+$#>KLotus Suspension Analysis – RAKVEN,  Introduction

Lotus Suspension provides a tool for the design of suspension characteristics using full vehicle handling analysis. Combinations of standard analysis modes are used to review vehicle response for the defined characteristics. The use of a non-multi body model, (only five parts are used, the sprung mass plus four un-sprung corner masses), allow the impact of individual characteristics to be assessed without reference to the constraints of a suspension mechanism.

{bmc bm0.bmp}
3D Graphical Display of Vehicle Model

Vehicle handling is assessed over either individual or combinations of Road Motion, Steering Motion, Acceleration and Braking. Each of these ‘motion’ sections has a number of individual pre-defined sub-tests, such as 1-wheel bump 2-wheel bump and sine sweep for the Road Motion. Currently the Adams solver is used to run the defined model over the prescribed event.

{bmc bm1.bmp}
Definition of the Road Motion Event

Results are displayed simultaneously as 3D animation of the model and x-Y graphs of selected results. Users can display any number of graphs each with their own unique display settings. A cross plot facility allows immediate comparison with previous analysis runs.

{bmc bm2.bmp}
Sample X-Y Results Graph Display

+$#>Overview – Introduction

The Raven module of Lotus Suspension Analysis provides an analysis tool for calculating the overall vehicle handling response under ‘standard’ road inputs, maneuvers and driver inputs. To do this a reduced degree of freedom model is used using only five parts, (sprung mass + the four un-sprung corner masses), and defining the relationship between them using combinations of splines. Each spline defines a particular characteristic, such as lateral force steer, which allows individual characteristics to be changed and their impact on the total handling response examined.

{bmc bm3.bmp}
Overall Appearance of Interface

The reduced mass model enables rapid analysis times, currently the solver uses ADAMS to solve the model. Raven is compatible with all recent versions of the ADAMS solver.

Data input for Raven can come from a number of sources. It can be entered directly by the user from any combination of estimates, measurements or other analysis tool results. It can be automatically produced from a full vehicle compliant SHARK model, (Shark is the Suspension kinematic and compliant module of Lotus Suspension Analysis which is licensed separately). It can come from measurements from an SKCMS rig. The SKCMS rig import is currently specific to Lotus Engineering SKCMS rigs, the import data file format is available for those wishing to convert alternative manufacturers rig results into the right format. The SKCMS file import does not at the current release level provide full a data set, some splines need to be defined after the import.

{bmc bm4.bmp}
Reviewing and editing the Spline data

Analysis runs are performed by selected the required solution type and submitting it via a command line option that writes an ADAMS *.adm and *.acf file. ADAMS then runs these files and the results files then loaded back into the interface. All of this is seamless to the user the file writing, solver start-up and results reading being carried out automatically once the job run is selected.

Results are displayed in both 3D graphical form and 2D X-Y graphs. The animation of the 3D viewer is linked to the graphs such that both displays can be used together to review the calculated behavior of the vehicle. Other options include cross plotting of two results for overall comparison between models.

{bmc bm5.bmp}
Cross plotting X-Y graphs

+$#>Overview – Defaults

All user definable settings are saved by the application when it has a normal program exit to its ‘ini’ file. The location of this ini file depends on the version of Windows currently being used. The file name is ‘shark.ini’ and will be saved to either C:\windows or C:\winnt. This file is not directly editable by the user but there are occasions when it is useful to understand where it is and what it stores.

All colours, symbols, visibility, line types and graphics size defaults that can be set by the user are saved to this file. In addition it will retain window sizes, folder settings, and recent open files.

At application start-up this file is searched for in the relevant Windows folder and if found read in to overwrite the internal default settings.

+$#>Overview – Graphical Interface

The graphical interface consists of a conventional Windows style container window, with a top menu bar and a series of status panels along the bottom.

Optional toolbars are drawn by default to the left of the window, containing short cut icons to some of the main menus. The user can specify the visibility of the toolbars together with their position. Additionally the toolbars can be displayed as ‘floating’ rather than anchored to one of the edges.

Floating toolbars can be re-docked to the required edge through picking and dragging to the new position, (note the outline shape will change to indicate docking).

The initial positions of the toolbars can be set via the SetUp / Start Options / ToolBar Position menu item, with Top, Bottom, Left or Right options available. This change is saved to the users ‘ini’ file and will be applied next time the application is re-started.

{bmc bm6.bmp}
Confirming the change in toolbar position

The suspension graphics is drawn in the window titled ‘3D Display’. This window cannot be closed, but can be repositioned, re-sized and minimized. Only one graphic window can be opened by the application at a time, (i.e. you cannot open different models at the same time using different graphic windows in the way that a multi-document application like Word would).

{bmc bm7.bmp}
Example 3D Graphic window

Results graphs are displayed in individual windows. Each new graph added opening a new window. The graph windows can be moved, re-sized, closed and minimized. The title of the graph window reflects the plotted variable.

{bmc bm8.bmp}
Example 3D Graph window

By default on start-up only the graphic window and toolbars are drawn, no graphs are displayed until they are added via the Graph / New/Open menu.

The settings for window positions, sizes and variables can be saved such that when the application is re-started all windows are re-opened in the same positions, see SetUp / Save Window Settings.

+$#>Overview – Dynamic Viewing

The main graphical window has dynamic viewing via the mouse, that allows translation, scaling and rotation, of the 3D graphics display.

The ‘dynamic view’ icon together with the associated menus indicate the status of the dynamic viewing mode, when checked the application is in dynamic view mode and the mouse and its buttons can be used to perform translation, scaling and rotation of the graphics model. Additionally the graphic display has symbols drawn in each corner as a visual indication that the application is in dynamic view mode.

{bmc bm9.bmp}
Dynamic Viewing – Indicators marked

The dynamic view mode has three options, being Translation, Scaling and Rotation. Each of these options has its own icon and menu item, View / Translate View, View / Scale View  and View / Rotate View. Selecting any of these options will enable dynamic viewing (if not currently on), or just change dynamic view type, (if already in dynamic view).

{bmc bm10.bmp}
Dynamic Viewing – View Type Icons

The dynamic view modes use the motion of the mouse between key down and key release to change the view. The translate view mode simply follows the translation of the mouse within the current view plane. The Scale view mode uses the mouse vertical position to scale the current view plane. Moving the mouse up scales the view out, (i.e. model appears further away), whilst moving the mouse down scales the view in.

The rotate dynamic view, has two actions depending on the position of  initial mouse selection point. Selecting towards the middle of the image will rotate the line of sight, whilst selecting towards the edge of the view will rotate the view around the line of sight only.

When in dynamic view mode the right mouse button will cycle through the available dynamic view options.

+$#>Overview – Graphs

The primary results display method for the application is through the x-y results graphs. Each graph show a single user selected parameters channel plotted against a second parameters channel (normally time). Any number of graphs can be opened and positioned within the display using either the Graphs / New/Open menu or equivalent icon.

{bmc bm11.bmp}
New Graph toolbar Icon

The appearance and settings of each graph can be changed through either the Graphs pull down menu or the graph’s right mouse menu. By selecting a graph with the right mouse button this implies that any changes made from the pop-up menu items is applied to the selected graph only.

{bmc bm12.bmp}
Graph right mouse button menu

As each new graph is opened the parameters and channels for x and y are set to the default values. To change the displayed parameters, use the right-mouse menu and select from the available Parameter list.

{bmc bm13.bmp}
Graph Parameter list - right mouse button menu

Additional Graph properties that can be defined are;

Axis Scales: Set the minimum and maximum x and y axis values. The autoscale option can also be used to automatically set the scales.

{bmc bm14.bmp}

Visibility: Set the visibility of individual graph items, Grid Lines, Point Symbols, Data Values.

Colours: Sets the colour of individual graph items, Grid Lines, Background, Axis Lines + Text, Border Region, Primary Results Line and Secondary Results Line.

{bmc bm15.bmp}

Line Markers: Set the marker for individual graph lines, Primary Results Line and Secondary Results Line.

{bmc bm16.bmp}

Marker Sizes: Sets the size of the markers used for each line type.

Text Sizes: Sets the size of the text labels for Graph Data Values.

Decimal Points Display: Defines the number of decimal points used to display numerical values. Individual values are X-Data Listing and Y-Data Listing.

+$#>Overview – Data Entry

Data entry is through standard Windows style dialogue boxes. These employ standard text and numeric widgets, together with check boxes and selection boxes. Spread sheet style entry where used supports cut and paste from external applications via the clipboard.

{bmc bm17.bmp}
Example spread sheet data entry

When using ‘paste’ into a Raven spread sheet it is only necessary to select the location of the top left hand cell of the paste are that the paste is intended to fill, do not drag and highlight the entire target area.

+$#>Getting Started – Start-up Steps

Starting the program can be considered to consist of the following steps;

1) Start the executable, locate either from the Start menu, (normally Start / Programs / Lotus Engineering Software / Lotus Suspension Analysis), or through explorer. Browse to the installed folder (normally c:\lesoft), and run the suspension analysis executable shark.exe, (note that shark.exe contains both the Shark and Raven modules of Lotus Suspension Analysis).

2) Select the module required, ‘Raven / STD Interface’. You should only need to do this if you are licensed for both ‘Shark’ and ‘Raven’ modules. If you are licensed for both ‘Shark’ and ‘Raven’ then the application will always open in the module that you last used. This setting, along with many others user definable settings, is stored in the ‘ini’ file.

3) Enter the required suspension data, either from an existing saved file or through the new file options.

{bmc bm18.bmp}

+$#>Getting Started – Program Start-up

During program start-up a number of system checks are performed. The users ini file is searched for and if found, loaded to overwrite the internal defaults.

+$#>Getting Started – Start-up Errors

During program start-up the searching for and subsequent loading of the users ‘ini’ file can in exceptional circumstances, results in an error message. This implies a corrupt ini file possibly due to a previous partial save or inappropriate editing, (the ini file should not be edited by hand).

{bmc bm19.bmp}
Error message ini file read failure

Selecting okay will continue to start the program, but with only a partial reading of the ini file, (partial up to the point of read error). Partial reading of the ini file may cause problems which may require the program to be closed and restarted. If the problems persists, (as it may, since the invalid settings will be written back into ini file when the program has a normal exit), the only option may be to delete the ini file, see Defaults.

Whilst strictly not a start-up error, the other possible start-up event that may occur is the detection of a previous runs temporary scratch file. This is interpreted as a previous run incorrectly shutting down, as these temporary scratch files used for the undo feature, are deleted on normal program exit.

If a scratch file(s) is identified, the user is given the option of recovering the most recent file and thus avoids potential data loss.

{bmc bm20.bmp}
Data Recovery Message

+$#>Getting Started – Graphics Frame Types

The interfaces main graphics display has two alternative drivers. The default device driver is a Windows GDI, (View / Graphics Frame Type / Windows GDI), which whilst it works with all Hardware options does so at the expense of both speed and capability. The GDI driver is unable to support depth buffered display and hence the view styles View / Fill Style / Hidden Line and View / Fill Style / Depth Buffered (Flat shaded ) do not function correctly. The alternative device driver is Open GL, (View / Graphics Frame Type / Open GL), which is both faster and supports depth buffering/hidden line display types.

Not all hardware is able to use the Open GL device type, typical failures are inability to refresh and lack of correct hidden line display.

+$#>Getting Started – Window Descriptions

The application window layout utilizes a Multi Document interface (MDI) style. Where display and graph windows are displayed as children of the main window. The main window has a top menu bar and two toolbars which have optional positions. The graphical display is drawn in a 3D viewing window, whilst individual graphs have separate windows.

{bmc bm21.bmp}
Example screen shot – Overall appearance of application

+$#>Getting Started – Module Type

On program start-up by default the application will go into whichever module was last used. If you are licensed for both the ‘Shark’ and ‘Raven’ modules you may need to switch modules once the application is open depending on which was used last.

The menu entry Module / Raven sub menu can be used to select the required module.

{bmc bm22.bmp}
Setting the application module – pull-down menu options

+$#>Getting Started – Data Entry

At start-up the main form of data entry to the program is either from a previously saved file, imported from a SKCMS rig results file or as a new file entering data directly through the various data section dialogue boxes. To load an existing data file use the File  / Open... menu item, (note that the five most recently opened files are appended to the File menu). To import SKCMS rig data use the File / Import SKCMS Rig File… menu. To create a new model select the File / New menu item then enter data for the ‘Vehicle’, ‘Tyre’ and ‘Solution’ data sets.

{bmc bm23.bmp}
Importing an SKCMS rig File – Selecting symmetry type

+$#>Getting Started – Exiting the Program

The close the program select the File / Exit menu item, and then confirm the ‘okay to exit’ prompt. Alternative methods to close the application include the conventional ‘X’ from the windows top right corner, Alt+F4 or close from the main windows top left menu. In addition the ‘esc’ key will close the application, (subject to accepting the prompt).

{bmc bm24.bmp}
Okay to exit prompt

+$#>Pull Down Menu Items - File

File / New: Creates a new model. This initializes the model data and enables the necessary data menus. The user is warned about possible existing data loss, being asked to confirm this action.

File / Open: Opens the standard Windows file browser to locate the required existing file to load. Note that file open action will lose the current model data.

File / Save As: Opens the standard Windows  file browser to enable the current model to be saved to disc. Browse to the required folder and enter/select the required file name.

File / Write .adm: Opens the standard Windows  file browser to define the required file name for the .adm file and folder. This menu option will normally be disabled for external Non-Lotus customers as part of the protection of Lotus intellectual property. Writes a ‘standard’ Adams ‘adm’ data file based on the current model definition.
 
File / Write .acf: Opens the standard Windows  file browser to define the required file name for the .acf file and folder. This menu option will normally be disabled for external Non-Lotus customers as part of the protection of Lotus intellectual property. Writes a ‘standard’ Adams ‘acf’ data file based on the current model definition and solution settings.

File / Load External Res… (Primary): Opens the standard Windows  file browser to locate and load a previously saved set of Adams results. Users can search for both *.req and *.gra files. Whichever type is located and loaded the other file type of the same name is automatically checked for and loaded if found. These results are then available to be displayed in the 3d graphics viewer (.gra) and the x-y graphs (.req). The label ‘Primary’ indicates that these are the main results displayed, they can be compared to a second set of results referred to as the ‘Secondary’ results which are loaded through a similar menu entry, (see below).

File / Load External Res… (Secondary): Opens the standard Windows  file browser to locate and load a previously saved set of Adams results. Users can search for both *.req and *.gra files. Whichever type is located and loaded the other file type of the same name is automatically checked for and loaded if found. These results are then available to be displayed in the 3d graphics viewer (.gra) and the x-y graphs (.req). The label ‘Secondary’ indicates that these are the comparison results, only being displayed when the relevant visibility switch is set to ‘on’ and when primary results have also been loaded.

File / Import SKCMS Rig File:  Opens the standard Windows file browser to locate the required existing file to load. The files required are those that have been produced from the Lotus SKCMS test rig and subsequently processed by the Lotus Controls data processing software. Note that this file import action will lose the current model data. The SKCMS file contains both averaged and individual Left/Right suspension data splines, thus the user is asked to define whether the imported model is required to be symmetrical, (in which case the averaged spline data is used) or asymmetric, (in which case the individual left and right splines are used).

File / Exit: Closes the application, subject to confirmation of ‘okay to exit’.

Appended to the bottom of the File menu, is a list of the last five (max) opened files.

+$#>Pull Down Menu Items – Module

Module / Shark / 2D Bump: Changes to the 2D module in Bump articulation mode. This will only be available if you are licensed for this full vehicle handling module, (licensed separately from Shark).

Module / Shark / 2D Roll: Changes to the 2D module in Roll articulation mode. This will only be available if you are licensed for this suspension kinematics module, (licensed separately from Raven).

Module / Shark / 3D Bump: Changes to the 3D module in Bump articulation mode. This will only be available if you are licensed for this suspension kinematics module, (licensed separately from Raven).

Module / Shark / 3D Roll: Changes to the 3D module in Roll articulation mode. This will only be available if you are licensed for this suspension kinematics module, (licensed separately from Raven).

Module / Shark / 3D Steer: Changes to the 3D module in Steer articulation mode. This will only be available if you are licensed for this suspension kinematics module, (licensed separately from Raven).

Module / Raven / STD Interface: Changes to the Raven module. 

+$#>Pull Down Menu Items - Data

Data / Vehicle: Displays the Vehicle data dialog box. All vehicle related property values can be displayed and edited through this display. All corner splines are similarly accessed through this via an additional pop-up display.

Data / Tyres: Displays the Tyre data dialog box. All tyre related properties can be viewed both numerically and graphically through this display. The selection of individual tyre model types and associated property files is similarly controlled/listed via this dialogue box.

Data / Solution: Displays the Solution control dialog box. The current solution mode is set via this display, with all related solution settings displayed in editable fields. The setting of single mode or multiple mode analysis is controlled by enabling a solution from more than one solution panel. 

+$#>Pull Down Menu Items - View

View / Refresh: Updates all graphical displays, both Graphics and Graphs.

View / Dynamic Viewing: Menu option to switch the  dynamic viewing mode on or off. Either by a toggle action or by specific selection..

View / Translate View: Sets the dynamic view mode to translate. If dynamic viewing is currently ‘off’ this will also cause the dynamic view mode to be turned ‘on’. Translation by left mouse button hold and move.

View / Scale View: Sets the dynamic view mode to scale. If dynamic viewing is currently ‘off’ this will also cause the dynamic view mode to be turned ‘on’. Scale by left mouse button hold and drag vertically.

View / Rotate View: Sets the dynamic view mode to rotate. If dynamic viewing is currently ‘off’ this will also cause the dynamic view mode to be turned ‘on’. Rotation by left mouse button hold and move.

View / Zoom: Pick the area of the display to zoom to fit current window. The zoom function can accommodate either a two press approach to area selection or a single press, hold and drag selection, a simple time delay trap being used to identify which type is being used. The zoomed view will retain the correct aspect ratio, (i.e. no distortion is allowed), and thus the final displayed region will include additional regions at either the top and bottom or both sides.

View / Autoscale (Ctrl+A): Resets the graphical view such that all drawn components appear within the display window. Note that this is only applied to the graphics window and not the graphs.

View / Fill Style: Sets the fill style to be used in the graphics display. Not all the fill style options are supported by every machine. Two graphics frame driver options are used one of which will not correctly support two of the fill styles. The fill styles available are, Wire Frame, Filled, Hidden Line and Depth Buffered (flat shaded). The later two will not work correctly unless the graphics frame type has been set to OpenGL

View / Std Views: Three orthogonal views are offered to aid simple planar viewing of the 3D model. The std views are y-z (front view), z-x (side view) and x-y (top view). Equivalent view toolbar icons are also available.

View / Saved Views / Save…: Saves the current 3D view settings to a temporary store, given a unique label for possible later retrieval. This temporary store only exists whilst the application is open such that all saved views are lost when the application is closed. Any number of views can be stored.

View / Saved Views / Recall Saved: Recalls a saved view, replacing the current view with that in the temporary store. Saved views are identified by their labels.

View / Saved Views / Delete Saved: Deletes a saved view from the temporary store. Only valid use is the simplifying of the displayed options through reduced menu list.

View / Saved Views / Delete All: Deletes all saved views from the temporary store. Quicker than deleting one at a time if looking to start the storing from scratch.

View / Set Background Colour…: Opens a standard colour selection dialog to pick a new colour for the background colour used in the graphics display. Note that graphs have their ow ncolour settings and are not affected by this change.

View / Graphics Frame Type: Sets the graphics frame device type as either Windows GDI or Open GL. The default device driver is a Windows GDI, (View / Graphics Frame Type / Windows GDI), which whilst it works with all Hardware options does so at the expense of both speed and capability. The GDI driver is unable to support depth buffered display and hence the view styles View / Fill Style / Hidden Line and View / Fill Style / Depth Buffered (Flat shaded ) do not function correctly. The alternative device driver is Open GL, (View / Graphics Frame Type / Open GL), which is both faster and supports depth buffering/hidden line display types.

Not all hardware is able to use the Open GL device type, typical failures are inability to refresh and lack of correct hidden line display.

View / Animation (Displacements): Switches on animation of the suspension(s) over the currently selected articulation type. All standard viewing and editing functions can still be used whilst the animation is on.

+$#>Pull Down Menu Items - Graphics

Graphics / Visibility: Toggles the visibility of specific classes of parts on the 3D graphical display. A class may include a number of individual graphical elements that together pictorially describe the ‘part’. The individual classes are; Front Tyres, Rear Tyres, Body C of G, ‘H’ Point, Front Spring/Damper, Rear Spring Damper, Front Roll Bar, Rear Roll Bar, Jacks, Ground Plane, Time counter and Axis Symbol. All settings are saved to the ini file.

Graphics / Visibility General: Toggles the visibility of individual graphical elements. Elements are identified by their type and No. Individual graphical element types are; Outlines, Circles, Arcs, Cylinders, Forces, Frustrums, Boxes and Spring/Dampers. The visibility settings are displayed in the form of a ‘tree’ structure. Expand each branch to find individual graphical elements or use the ‘All’ option to control the visibility of whole graphical type sets. All settings are saved to the ini file.

Graphics / Colours: Defines the colour of specific classes of parts on the 3D graphical display. The individual classes are; Front Tyres, Rear Tyres, Body C of G, ‘H’ Point, Front Spring/Damper, Rear Spring Damper, Front Roll Bar, Rear Roll Bar, Jack Plates, Jack Upper, Jack Lower, Ground Plane and Time Counter. All settings are saved to the ini file. Colour settings are changed by selecting the required new colour from the displayed palette. 

Graphics / Colours General: Defines the colour of individual graphical elements. As for visibility elements are identified by their type and No. Individual graphical element types are; Outlines, Circles, Arcs, Cylinders, Forces, Frustrums, Boxes and Spring/Dampers. The colour settings are displayed in the form of a ‘tree’ structure. Expand each branch to find individual graphical elements or use the ‘All’ option to control the colour of whole graphical type sets. All settings are saved to the ini file. The available colours are listed in the form of a menu option, note that fewer colour options are available through this than with the previous menu option.

Graphics / Dim. Properties: Displays for editing the dimensional properties for graphical element classes. The listed properties control the physical size of the specific class. Each class has its own specific list of properties. Changes made to the graphical properties will have no effect on the currently displayed elements, they will only affect subsequent runs results. The graphical classes that have properties are; Front Tyres, Rear Tyres, Body, C of G, ‘H’ Point, Front Spring Damper, Rear Spring Damper, Front Roll Bar, Rear Roll Bar, Jacks and Ground Plane.

Graphics / Moving Eye: Toggles the ‘moving eye’ animation option on/off. When ‘on’ the moving eye modifies the animation view of the 3D graphical results such that the eye point moves with the specified part. The required part to ‘follow’ is identified through a separate menu. The moving eye can follow the part motion in all three axes or combinations as required, (set by separate toggle switches). A delay in following can also be defined such that there is a lag between the actual motion and the moving eye. This gives a feel for the motion direction but keeps the components within the displayed region.

Graphics / Follow Part: Opens a selection box listing the currently available parts. The current selection will be highlighted. To change to another part select it and confirm via the ‘ok’ button.

Graphics / Follow X: Toggles the setting for the moving eye following the x-axis motion of the selected part.
 
Graphics / Follow Y: Toggles the setting for the moving eye following the y-axis motion of the selected part.

Graphics / Follow Z: Toggles the setting for the moving eye following the z-axis motion of the selected part.

Graphics / Follow Delay: Toggles the follow delay switch. Controls whether the defined delay is applied to the moving eye view. Only effects the 3D view when in ‘moving eye’ animation mode.

Graphics / Delay Size: Defines the magnitude of the delay in terms of calculation steps. It only effects the 3D view if both ‘Moving Eye’ and ’Follow Delay’ are turned on. Note this actual delay value time depends on the solution time step size since this setting is based on the number of calculation steps.

Graphics / Secondary Graphics: Controls the visibility of the loaded secondary graphics. Controls both 3D graphics and opened graphs. Will only impact the displays if a results file has been loaded into the secondary slot via the external file load menu or via the job submission options.

Graphics / Moving  Ground: Toggles the moving ground option. When ‘on’ this visually rotates the wheel graphical elements and shifts the ground plane X lines to give the impression of forward motion.

Graphics / Copy to Clipboard: Copies the current graphical display to the Windows clipboard such that it can be pasted into other applications.

+$#>Pull Down Menu Items - Graphs

Graphs / New/Open: Opens a new graph window. Each new graph will by default take the use y-variable from the available list. To change the y-variable once opened use the mouse right button menu options.

Graphs / Visibility: Controls the visibility of the graph items. Options are given to switch individual graph items on and off. For the purpose of this menu the ‘graph’ items are; Grid Lines, Point Symbols and Data Values.

Graphs / Colours: Provides control over individual graph element colours. Modified colour settings are stored to the users ini file. The graph elements that can be defined via this menu include; Grid Lines, Background, Axis Lines and Text, Border Region, Primary Results Line and Secondary Results Line.

Graphs / Line Marker: Provides control over individual graph line markers. Modified marker settings are saved to the users ini file. The graph lines that marker types can be defined for are; Primary Results Line and Secondary Results Line. The nine marker types available are Filled Diamond, Triangle, Inverted Triangle, Plus, Cross, Square, Diamond, Circle and Star.

Graphs / Line Marker / Set to Defaults: Single menu selection to set all relevant graph line marker symbols back to the default settings. For relevant elements see previous menu item.

Graphs / Autoscale (All): Autoscales all open graphs for both x and y-axes. Includes all visible lines. To autoscale individual graphs use the mouse right button menu item.

Graphs / Marker/Text Sizes / Edit Sizes: Displays the graph marker and text sizes for viewing and editing. Changes are stored to the users ini file. Properties that can be edited include; Data Line Marker Size and Graph Data Values Text Size.

Graphs / Marker/Text Sizes / Set to Defaults: Single menu selection to set all relevant graph marker and text sizes back to the default settings. For relevant elements see previous menu item.

Graphs / Decimal Points Display / Edit Settings: Displays the graph decimal points display for viewing and editing. Changes are stored to the users ini file. Properties that can be edited include; X-Data Listing and Y-Data Listing.

Graphs / Decimal Points Display / Set to Defaults: Single menu selection to set all relevant graph decimal points displays back to the default settings. For relevant elements see previous menu item.

+$#>Pull Down Menu Items - Solve

Solve / Submit: Creates a new solution run. Based on the current model settings and solution settings this option writes an *.adm and *.acf file before running the standard ADAMS solver. Options are offered as to whether the results files should be permanently saved to the hard disc and how to load the results files upon job completion. Before this option can be used successfully users must ensure that they have edited the settings for the Batch File and the Command Line Arguments, (see later descriptions for these items).

Solve / Tolerances: A number of solver tolerances are edited through this menu item. They are included in the written adm and acf files and control the ADAMS solver run. The tolerances listed are; ERROR Tolerance, ALIMIT Tolerance, TLIMIT Tolerance and INTEGRATOR Tolerance. Users should refer to the appropriate ADAMS documentation for descriptions of these variables.

Solve / Command Line Arguments: Defines the command line arguments used to run the ADAMS solver. The minimum should be ‘ru-user’. Normally this would also include the path and name of the varsub.dll file supplied as part of the installation. Without the dll path and name on the command line, no tyre models other than the ‘mal’ tyre can be used. If the Lotus software has been installed into the default folder the setting for this would normally be ‘ru-user C:\lesoft\varsub.dll’.

Solve / ADAMS Batch File: Defines the path and name of the ADAMS solver ‘mdi.bat’ file. This would normally be in a sub folder of ‘Program Files’, but the exact folder name will vary depending on the actual version of ADAMS installed on the machine. As an example for Adams version 12.0 the setting for this would be ‘C\Program Files\ADAMS 12.0\common\mdi.bat’.

Solve / Solution Data: Displays the Solution control dialog box. The current solution mode is set via this display, with all related solution settings displayed in editable fields. The setting of single mode or multiple mode analysis is controlled by enabling a solution from more than one solution panel. 

Solve / Road Motion: Provides a visual check on the current Road Motion setting, and a quick route to change between Road Motion options.

Solve / Steering Motion: Provides a visual check on the current Steering Motion setting, and a quick route to change between Steering Motion options.

Solve / Braking/Accel.: Provides a visual check on the current Braking/Acceleration setting, and a quick route to change between the Braking and Acceleration options.

+$#>Pull Down Menu Items - SetUp

SetUp / Start Options / Toolbar Icons: Provides an option for two styles of icons. Select from either Standard or Mouse Sensitive. Standard icons have permanently visible boundaries to the icon, whilst mouse sensitive icons ‘raise’ as the mouse passes over them. This change is stored to the ini file and will only be implemented on next program start-up.

SetUp / Start Options / Toolbar Position: Sets the default starting position for the toolbars. All visible toolbars will be placed in this position when the application starts up. Once started the user can choose to change the toolbar positions individually as required. The four available positions are Top, Bottom, Left or Right. This change is stored to the ini file and will only be implemented on the next program start-up.

SetUp / Start Options / Maximised: If checked defines that the application will start up with the main window maximised, (i.e. expanded to fill the current screen size). Note that if the application is maximised during use, then this will also set the ‘maximised’ setting. This change is stored to the ini file and will be implemented on next program start-up.

SetUp / Exception Handler On: Provides a software trapping routine to handle application exception failures. Whilst this won’t enable the user to recover the current session it will prevent the exception causing a complete system failure. Not normally required this release.

SetUp / Save Def. Window Settings: When set this options will save to the users ini file the current size, positions and settings of the graphics and graph windows, such that on a subsequent program start-up all windows will be re-created in the same position/size as previously. They are referred to ‘default’ since users can store different settings to alternative files.

SetUp / Save Window Settings to…: This option allows the user to save the current window and graph settings to a file. These settings can then be retrieved at a later stage or in future runs.

SetUp / Load Window Settings from…: This option allows the user to retrieve from a previously saved file the settings for the main window and graphs. These settings included not only position and size but also displayed variables and axis settings.

SetUp / View Toolbar Visibility: Sets the visibility option for the View toolbar. This setting is saved to the ini file and will thus be applied to future runs.

SetUp / File + Data Toolbar Visibility: Sets the visibility option for the File and Data toolbar. This setting is saved to the ini file and will thus be applied to future runs.

+$#>Pull Down Menu Items - Window

Window / Tile Horizontal: Automatic window positioning option that lays open windows in to a primarily horizontal layout.

Window / Tile Vertical: Automatic window positioning option that lays open windows in to a primarily vertical layout. 

Window / Cascade: Automatic window positioning option. All open windows are re-sized to a common size and cascaded down from the top left hand corner in regular steps.

The Window menu has appended to it an entry for each child window. Child windows include graphic displays all graphs and results displays.

+$#>Pull Down Menu Items - Help

Help / Contents (F1): Opens this help file at the contents page.

Help / Search for Help On…: Opens this help file at the ’index’ page to allow for searching through the help file by key words.

Help / How to Use Help: Opens the standard Windows® Help document, describing how to use on-line help files.

Help / About Lotus Suspension Analysis…: Displays the Lotus Suspension Analysis ‘about’ box listing both the major and minor release levels. Support contact details are also given.

+$#>Mouse Right Button Menu Items – Graphics

No specific menus are used on the graphics display for the right mouse button, Instead it is used as a quick cycle through the dynamic viewing modes for the current dynamic viewing status.

In the view zoom mode the right mouse button will cancel the zoom event.

+$#>Mouse Right Button Menu Items – Graphs

X-Parameter: Used to change the displayed x-axis parameter No. for the selected graph. Lists all available options, (some may not be relevant to the current module or model). The current variable is shown checked in the list. A selection is a combination of the parameter and channel No. Each parameter has 6 possible channels.

X-Channel: Used to change the displayed x-axis channel No. for the selected graph. Lists all available options, (some may not be relevant to the current module or model). The current variable is shown checked in the list. A selection is a combination of the parameter and channel No.
 
Y-Parameter: Used to change the displayed y-axis parameter No. for the selected graph. Lists all available options, (some may not be relevant to the current module or model). The current variable is shown checked in the list. A selection is a combination of the parameter and channel No. Each parameter has 6 possible channels.

Y-Channel: Used to change the displayed y-axis channel No. for the selected graph. Lists all available options, (some may not be relevant to the current module or model). The current variable is shown checked in the list. A selection is a combination of the parameter and channel No.

Autoscale: Autoscales the selected graph for both x and y-axes. Includes all visible lines on the graph. To autoscale all graphs use the main menu or equivalent toolbar icon.

Zoom: Pick the area of the selected graph to fit the current window. The zoom function can accommodate either a two press approach to area selection or a single press, hold and drag selection, a simple time delay trap being used to identify which type is being used. The zoomed area will become the plotted region.

Axis Scales: Displays the selected graphs x and y-axis settings. Axes are defined simply by the minimum and maximum values.

List Primary Results Line: Lists the selected graphs primary results line for viewing. As these are calculated results they are display only.

Copy to Clipboard: Copies the selected graph display to the Windows clipboard such that it can be pasted into other applications.

+$#>Icon Description – General

The following icons are used within the application dialogue boxes. A brief description is given for each.

{bmc bm25.bmp} Generic Editor Icon, normally opens standard data editor display.

{bmc bm26.bmp} Opens this Help File at context sensitive page

+$#>Icon Description – View Toolbar

The following icons are displayed on the view toolbar. A brief description is given for each.

{bmc bm27.bmp} Toggle dynamic viewing on/off.

{bmc bm28.bmp} Set dynamic view on and mode to translate.

{bmc bm29.bmp} Set dynamic view on and mode to scale.

{bmc bm30.bmp} Set dynamic view on and mode to rotate.

{bmc bm31.bmp} Start zoom event on the graphics display.

{bmc bm32.bmp} Autoscale all open graphs.

{bmc bm33.bmp} Set graphics view style to Wire Frame.

{bmc bm34.bmp} Set graphics view style to Solid Fill.

{bmc bm35.bmp} Set graphics view style to Hidden Line.

{bmc bm36.bmp} Set graphics view style to Depth Buffered (flat shaded).

{bmc bm37.bmp} Set graphics view to Y-Z plane.

{bmc bm38.bmp} Set graphics view to X-Z plane.

{bmc bm39.bmp} Set graphics view to X-Y plane.

{bmc bm40.bmp} Save current graphics view to temporary store.

{bmc bm41.bmp} Cycle though the available dynamic view options.

+$#>Icon Description – File + Data Toolbar

The following icons are displayed on the File toolbar. A brief description is given for each.

{bmc bm42.bmp} Create a new data file.

{bmc bm43.bmp} Open existing data file.

{bmc bm44.bmp} Save data to file

{bmc bm45.bmp} Edit/View Vehicle data 

{bmc bm46.bmp} Edit/View Tyre data

{bmc bm47.bmp} Edit/View Solution data

{bmc bm48.bmp} Toggle Body visibility

{bmc bm49.bmp} Toggle Jacks visibility

{bmc bm50.bmp} Toggle ground plane visibility

{bmc bm51.bmp} Moving eye point viewing

{bmc bm52.bmp} Animate model

{bmc bm53.bmp} Copy display to clipboard

{bmc bm54.bmp} Open new results graph

{bmc bm55.bmp} Autoscale (all) results graphs

{bmc bm56.bmp} Submit analysis job

+$#>Data Requirements - Introduction

This section describes the data requirements for the Raven analysis module. Each data variable is listed, together with its units and any default value.

The listings are broken down into sections as they are displayed in the interface.

+$#>KData Requirements – Co-ordinate System

The ‘RAVEN’ co-ordinate system is a right handed system with the Y-axis across the car track, the origin of which is assumed to be on the vehicle centre line and the +ve direction being towards the offside suspension (Right hand Corner sitting in car). The X-axis is along the vehicle wheelbase with the +ve direction towards the rear.

{bmc bm57.bmp}
‘RAVEN’ Co-ordinate System

+$#>Data Requirements – Vehicle Data

The vehicle data display provides access to all vehicle related model data. To open this dialog box select the menu item Data / Vehicle... or the equivalent icon.

{bmc bm45.bmp}
Vehicle Data Display Icon

Vehicle data is split into three types:

1)	Individual vehicle values
1)	Corner Values
1)	Corner Splines

The individual vehicle values are always displayed on the vehicle graphic in their respective boxes. Corner values are only shown in the corner editable boxes when selected from the Corner-Data menu list. Corner splines are never listed directly on the main display, access to the splines being through pop-up displays.

{bmc bm58.bmp}
Main Vehicle Data Display

Each data type will be listed separately.

Individual Vehicle Values

Front Track,  (real),  (units m)
The lateral distance between the centres of tyre contact of a pair of front wheels, (SAE J670e)

No. of Tyres Front Corner,  (integer)
Sets the number of tyres at each front corner. Normally this would be one.

Front Single Wheel Damper Rate,  (real),  (units Ns/m)
The rate of the viscous damping force of a single front wheel, in vertical displacement, which is proportional and opposite in direction to the wheel vertical velocity. (Note Damping is equivalent to at the wheel).

Front Tyre Relaxation Angle,  (real),  (units Rad)
The 1st order lag angle. Used to define the rate of lateral force rise as a function of vertical load, at a specified pressure and temperature for the front tyre. Can also be accessed through the Tyre data display.

Steering Ratio,  (real)
Defines the ratio between hand wheel angle and tyre steer angle.

‘H’ Point X, Y and Z,  (real),  (units m)
Defines the position of the ‘H’ point relative to the C of G position. Locates the point for specific output response results to be calculated for.

Wheelbase,  (real),  (units m)
The fore/aft distance between the centres of tyre contact of a pair of axles.

Sprung C of G Height,  (real),  (units m)
Sets the height of the sprung mass’s C of G position above the ground plane.

Sprung Mass,  (real),  (units kg)
All mass which is supported by the suspension, includes portions of the mass of the suspension members, (SAE J670e).

Total Front Weight Split,  (real),  (units %)
Defines the vehicle total weight split between the front and rear axles, by defining the % weight on the front axle.

Sprung Inertia, X-X, Y-Y and Z-Z,  (real),  (units kg.m2)
Defines the inertia of the sprung mass about the three global axes. The inertia values should not include the inertial component due to the un-sprung corner weights.

Rear Track,  (real),  (units m)
The lateral distance between the centres of tyre contact of a pair of rear wheels, (SAE J670e)

No. of Tyres Rear Corner,  (integer)
Sets the number of tyres at each rear corner. Normally this would be one.

Rear Single Wheel Damper Rate,  (real),  (units Ns/m)
The rate of the viscous damping force of a single rear wheel, in vertical displacement, which is proportional and opposite in direction to the wheel vertical velocity. (Note Damping is equivalent to at the wheel).

Rear Relaxation Angle,  (real),  (units Rad)
The 1st order lag angle. Used to define the rate of lateral force rise as a function of vertical load, at a specified pressure and temperature for the rear tyre. Can also be accessed through the Tyre data display.

Corner Values

Corner values are only displayed in the editable boxes when that particular variable has been selected from the Corner Data / Single Values menu list. The listed value’s description is shown to the left of the edit box to indicate the displayed variable. If the ‘Edit Data’ icon is shown rather than an editable field this is because a Corner Spline has been selected rather than a Corner Value.

As an alternative all Corner Values can be displayed together using the Corner Data / Single Values / Display Full List menu option.

{bmc bm59.bmp}
Vehicle Data ‘All Corner Values’ Display

Depending whether the model is defined as symmetrical or asymmetrical will affect if both Left and Right sides are listed/editable. For a symmetrical model only the right hand side is displayed/editable. The Left hand side being assumed the same/mirrored.

The list of corner values includes;

Unsprung Mass,  (real),  (units kg)
Defines the un-sprung mass for one corner of the car. Un-Sprung mass is defined as all mass which is not carried by the suspension system, but is supported directly by the tyre or wheel and is considered to move with it.

Tyre Vertical Stiffness,  (real),  (units N/m)
Sets the tyre vertical stiffness for each corner at a specified load and inflation pressure. This value can also be edited through the Tyre data section. The Tyre Vertical Stiffness, Tyre Vertical Damping and Tyre Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle).

Tyre Vertical Damping,  (real),  (units N.s/m)
Sets the tyre vertical damping for each corner at a specified load and inflation pressure. This value can also be edited through the Tyre data section. The Tyre Vertical Stiffness, Tyre Vertical Damping and Tyre Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). If this field is not editable it is because the interface is currently set to define the damping via the loss angle rather than directly with the damping value. The setting of whether to use the loss angle or the damping value is controlled by the Vehicle Data menu item Loss Angle / Use Loss Angles.

Non Dimensional Cornering Stiffness,  (real)
Sets one of the tyre characteristics for the simple MAL tyre model. A non-dimensional coefficient that defines the tyre lateral force as a function of the slip angle and vertical load. This value is also editable through the Tyre data section.

Non Dimensional Camber Stiffness,  (real)
Sets one of the tyre characteristics for the simple MAL tyre model. A non-dimensional coefficient that defines the tyre camber thrust as a function of the camber angle and vertical load. This value is also editable through the Tyre data section.

Bush Lateral Stiffness,  (real),  (units N/m)
Sets the bush lateral stiffness properties for each corner. This is the bush connecting the unsprung corner mass to the sprung mass. The Bush Lateral Stiffness, Bush Lateral Damping and Bush Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). 

Bush Lateral Damping,  (real),  (units N.s/m)
Sets the bush lateral damping for each corner. This is the bush connecting the unsprung corner mass to the sprung mass. The Bush Lateral Stiffness, Bush Lateral Damping and Bush Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). If this field is not editable it is because the interface is currently set to define the damping via the loss angle rather than directly with the damping value. The setting of whether to use the loss angle or the damping value is controlled by the Vehicle Data menu item Loss Angle / Use Loss Angles.

Bush Longitudinal Stiffness,  (real),  (units N/m)
Sets the bush longitudinal stiffness properties for each corner. This is the bush connecting the unsprung corner mass to the sprung mass. The Bush Longitudinal Stiffness, Bush Longitudinal Damping and Bush Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). 

Bush Longitudinal Damping,  (real),  (units N.s/m)
Sets the bush longitudinal damping for each corner. This is the bush connecting the unsprung corner mass to the sprung mass. The Bush Longitudinal Stiffness, Bush Longitudinal Damping and Bush Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). If this field is not editable it is because the interface is currently set to define the damping via the loss angle rather than directly with the damping value. The setting of whether to use the loss angle or the damping value is controlled by the Vehicle Data menu item Loss Angle / Use Loss Angles.

Static Toe,  (real),  (units Deg)
Sets the static toe angle for each corner. The sign convention is based on the right hand grip rule about the global Z-axis, thus the conventional ‘toe-in’ would give a different sign for the right (+ve) and left (-ve) suspension sides. Toe angle is defined as the angle between a longitudinal axis of the vehicle and the line of intersection of the wheel plane and the road surface, (SAE J670e).

Static Camber,  (real),  (units Deg)
Sets the static camber angle for each corner. The sign convention is based on the right hand grip rule about the global X-axis, thus the conventional ‘negative camber’ would give a different sign for the right (+ve) and left (-ve) suspension sides. Camber angle is defined as the inclination of the wheel plane to the vertical, (SAE J670e).

Wheel Diameter,  (real),  (units m)
Defines the wheel diameter for each corner.

Wheel Inertia,  (real),  (units kg/m2)
Defines the wheel inertia for each corner.

Tyre Loss Angle,  (real),  (units deg)
Sets the Tyre Loss angle for each corner. This value can also be edited through the Tyre data section. The Tyre Vertical Stiffness, Tyre Vertical Damping and Tyre Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). If this field is not editable it is because the interface is currently set to define the damping directly with the damping value rather than via the loss angle rather. The setting of whether to use the loss angle or the damping value is controlled by the Vehicle Data menu item Loss Angle / Use Loss Angles.

Bush Loss Angle,  (real),  (units deg)
Sets the Bush Loss Angle for each corner. The Bush Stiffness’s, Bush Damping and Bush Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). If this field is not editable it is because the interface is currently set to define the damping via the loss angle rather than directly with the damping value. The setting of whether to use the loss angle or the damping value is controlled by the Vehicle Data menu item Loss Angle / Use Loss Angles.

Corner Splines

Corner splines are only displayed by selecting either the individual Edit Data button when that particular variable has been selected from the Corner Data / Splines menu list or a from the combined displaye using the Corner Data / Splines / Display Full List menu option.

{bmc bm60.bmp}
Vehicle Data ‘Display Full List’ Display

Depending whether the model is defined as symmetrical or asymmetrical will affect if both Left and Right sides are listed/editable. For a symmetrical model only the right hand side is displayed/editable. The Left hand side being assumed the same/mirrored.

The list of corner splines includes;

Toe Change Bump,  (real),  (units m,deg)
List the change in Toe angle for each wheel with bump/rebound motion.

Camber Change Bump,  (real),  (units m,deg)
List the change in Camber angle for each wheel with bump/rebound motion.

Toe Change Roll,  (real),  (units m,deg)
List the change in Toe angle for each wheel with roll motion. Currently this is not used by the adm so can be left undefined unless the user has set the Spline-Type setting to Roll.

Camber Change Roll,  (real),  (units m,deg)
List the change in Camber angle for each wheel with roll motion. Currently this is not used by the adm so can be left undefined unless the user has set the Spline-Type setting to Roll.

Opposed Lateral Force Steer,  (real),  (units N,deg)
List the change in Toe angle of each wheel for opposed lateral forces applied to each upright at the tyre contact point.

Parallel Lateral Force Steer,  (real),  (units N,deg)
List the change in Toe angle of each wheel for parallel lateral forces applied to each upright at the tyre contact point.

Opposed Trailed Lateral Force Steer,  (real),  (units N,deg)
List the change in Toe angle of each wheel for opposed trailed lateral forces applied to each upright at 30 mm behind the tyre contact point.

Parallel Trailed Lateral Force Steer,  (real),  (units N,deg)
List the change in Toe angle of each wheel for parallel trailed lateral forces applied to each upright at 30 mm behind the tyre contact point.

Opposed Wheel Vertical Force,  (real),  (units m,N)
List the change in tyre vertical force for opposed vertical displacement of the tyre contact point.

Parallel Wheel Vertical Force,  (real),  (units m,N)
List the variation in tyre vertical force for parallel vertical displacement of the tyre contact point.

Single Wheel Brake Steer,  (real),  (units N,deg)
List the change in Toe angle of each wheel for a single longitudinal force applied to the upright at the tyre contact point.

Parallel Wheel Brake Steer,  (real),  (units N,deg)
List the change in Toe angle of each wheel for parallel longitudinal forces applied to each upright at the tyre contact point.

Track Change Gradient,  (real),  (units m, mm/mm)
List the variation in the rate of change of track for each wheel over bump/rebound motion.

Lateral Force Camber Compliance,  (real),  (units N, deg)
List the change in the camber angle of each wheel for lateral forces applied to each upright at the tyre contact point.

Wbase TCP Gradient,  (real),  (units m, mm/mm)
List the variation in the rate of change of the wheelbase for each wheel over bump/rebound motion for the Tyre contact point.

Wbase Hub Gradient,  (real),  (units m, mm/mm)
List the variation in the rate of change of the wheelbase for each wheel over bump/rebound motion for the Hub point.

Ackermann,  (real),  (units deg, deg)
Not strictly the variation in Ackermann % but the relationship of the wheel toe angles with change in steering hand wheel angle. Is only applicable for the front corners.

Steer Jacking,  (real),  (units deg, N)
List the change in tyre vertical force due to steering. Vertical force is listed against toe angle for each wheel at the normal ride height. Is only applicable for the front corners.

+$#>Data Requirements – Tyre Data

The tyre data display provides access to all tyre related model data. To open this dialog box select the menu item Data / Tyre... or the equivalent icon.

{bmc bm46.bmp}
Tyre Data Display Icon

The primary function of the tyre display window is to select the required tyre model and graphically display the defined tyre properties. The tyre properties displayed graphically are Lateral Force, Aligning Torque and Longitudinal Force. The Longitudinal Force option is only relevant for the ‘Modified Delft’ model option.

{bmc bm61.bmp}
Tyre Data Display – Showing Lateral Force Plot

Each tyre model has its own unique data requirements, usually in the form of a series of coefficients, or a complete data file.

The secondary function of the tyre display window is to list for editing/display the other tyre related model properties. Some of these can also be edited through the vehicle data display.

{bmc bm62.bmp}
Tyre General Data Display

Tyre General Data

Unloaded Radius,  (real),  (units m)
Defines the rolling radius for the tyre.

Vertical Stiffness,  (real),  (units N/m)
Defines the tyres vertical stiffness. The Tyre Vertical Stiffness, Tyre Vertical Damping and Tyre Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle).

Vertical Damping,  (real),  (units Ns/m)
Sets the tyre vertical damping. The Tyre Vertical Stiffness, Tyre Vertical Damping and Tyre Loss Angle values are linked via the relationship, Damping = Stiffness x Sin(Loss Angle). The setting of whether to use the loss angle or the damping value is controlled by the Vehicle Data menu item Loss Angle / Use Loss Angles.

Lateral Stiffness,  (real),  (units N/m)
Defines the tyre lateral stiffness value. Only used with the Adams carpet plot type tyre model.

‘Mu’ Dynamic,  (real)
Defines the Dynamic coefficient of friction. Only used with the Adams carpet plot type tyre model.

‘Mu’ Static,  (real)
Defines the Static coefficient of friction. Only used with the Adams carpet plot type tyre model.

Dynamic Velocity,  (real),  (units m/s)
Defines the Dynamic velocity value for the tyre model. Only used with the Adams carpet plot type tyre model.

Static Velocity,  (real),  (units m/s)
Defines the Static velocity value for the tyre model. Only used with the Adams carpet plot type tyre model.

Rolling Resistance Coefficient,  (real)
Defines the Rolling resistance coefficient value for the tyre model. Only used with the Adams carpet plot type tyre model.

Equivalent Plane Angle,  (real)
Defines the Equivalent plane angle value for the tyre model. Only used with the Adams carpet plot type tyre model.

Equivalent Plane Increment,  (real)
Defines the Equivalent plane increment value for the tyre model. Only used with the Adams carpet plot type tyre model.

Tyre Relaxation Angle,  (real),  (units rad)
The 1st order lag angle. Used to define the rate of lateral force rise as a function of vertical load, at a specified pressure and temperature for the tyre. Can also be accessed through the Vehicle data display.

MAL - Tyre Model Data

Non Dimensional Cornering Stiffness,  (real)
A non-dimensional coefficient that defines the tyre lateral force as a function of the slip angle and vertical load. This value is also editable through the Tyre data section.

Non Dimensional Camber Stiffness,  (real)
A non-dimensional coefficient that defines the tyre camber thrust as a function of the camber angle and vertical load. This value is also editable through the Tyre data section.

Tyre ‘mu’,  (real)
Defines the limiting lateral mu for the tyre.

Saturation Force,  (real),  (units N)
Defines the vertical force saturation value fro the tyre.

Tyre Width,  (real),  (units m)
Defines the overall tyre width.

Vertical Force Coefficient,  (real)
A non-dimensional coefficient that defines the tyre vertical force behaviour.

Pacejka - Tyre Model Data

Lateral Force Coefficients,  (real)
Pacejka uses 15 ‘A’ coefficients to describe the variation of tyre lateral force with variation in Vertical force, slip angle and camber angle.

A0, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A111, A112, A12 and A13

Aligning Torque Coefficients,  (real)
Pacejka uses 18 ‘C’ coefficients to describe the variation of tyre aligning torque with variation in Vertical force, slip angle and camber angle.

C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16 and C17

Delft - Tyre Model Data

Lateral Force Coefficients,  (real)
Delft uses 19 ‘A’ coefficients to describe the variation of tyre lateral force with variation in Vertical force, slip angle and camber angle.

A0, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A111, A12, A13, A14, A15, A16, A17 and FZ0

Aligning Torque Coefficients,  (real)
Delft uses 25 ‘C’ coefficients to describe the variation of tyre aligning torque with variation in Vertical force, slip angle and camber angle.

C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23 and R0

Modified Delft - Tyre Model Data

Lateral Force Coefficients,  (real)
Modified Delft uses 30 ‘A’ coefficients to describe the variation of tyre lateral force with variation in Vertical force, slip angle and camber angle.

A0, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A111, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28 and FZ0

Aligning Torque Coefficients,  (real)
Modified Delft uses 29 ‘C’ coefficients to describe the variation of tyre aligning torque with variation in Vertical force, slip angle and camber angle.

C0, C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C27 and R0

Longitudinal Force Coefficients,  (real)
Modified Delft uses 18 ‘L’ coefficients to describe the variation of tyre longitudinal force with variation in Vertical force, slip angle and camber angle.

L0, L1, L2, L3, L4, L5, L6, L7, L8, L9, L10, L11, L12, L13, L14, L15, L16, L17 and L18

Adams Carpet/Tyre - Tyre Model Data

Lateral Force,  (real),  (N)
Listed in a data file as a fully populated 3D array of lateral force variation with vertical force, slip angle and camber angle.

Aligning Torque,  (real),  (Nm)
Listed in a data file as a fully populated 3D array of aligning torque variation with vertical force, slip angle and camber angle.

+$#>KData Requirements – Solution Data

The Solution data display provides access to all solution related settings. To open this dialog box select the menu item Data / Solution... or the equivalent icon.

{bmc bm47.bmp}
Solution Data Display Icon

The solution data is subdivided into three solution classes; Road motion, Steering Motion and Acceleration/Braking. Additional general solution data/settings can also be edited through this display, (see pull down menus).

Solution Control

The following values are listed independent of the solution class, (for further information on solution control variables refer to the relevant ADAMS documentation).

End Time,  (real),  (s)
Sets the end of solution time value. Solution will run till this value provided no errors occur.

No. of Solution Steps,  (integer)
Defines the number of solution time steps used over the defined run time.

Road Motion

{bmc bm63.bmp}
Solution Data  - Road Motion

Road Motion Types,  (choice)
Three road motion types are available; 1-Wheel Bump, 2-Wheel Bump and Sine Sweep.

Velocity,  (real),  (m/s)
Defines the vehicle forward speed for the analysis event.

Start Time,  (real),  (s)
Defines the point in the analysis event when the start of the bump is reached by the front axle.

Bump Height,  (real),  (m)
Sets the maximum height of the bump above the ground plane.

Length Up,  (real),  (m)
Defines the length of the ‘up-ramp’ of the bump, distance taken to reach the maximum bump height from ground plane.

Dwell Length,  (real),  (m)
Defines the length of the bump at the maximum bump height..

Length Down,  (real),  (m)
Defines the length of the ‘down-ramp’ of the bump, distance taken to reach the ground plane from the maximum bump height.

Steer Input,  (real),  (deg)
Defines the magnitude of the steering input of the input sine wave.

Phase,  (real),  (rad)
Defines the initial phase of the input sine wave.

Time Offset,  (real),  (s)
Defines the time delay to the start of the sine wave steering input.

Steering Motion

{bmc bm64.bmp}
Solution Data  - Steering Motion

Steering Motion Types,  (choice)
Five steering motion types are available; Step Change, Ramp Up, Lane Change, Sine Sweep and Steering Pad.

Velocity,  (real),  (m/s)
Defines the vehicle forward speed for the analysis event.

Start Time,  (real),  (s)
Defines the point in the analysis event when the steering event starts.

Steer Input,  (real),  (deg)
Defines the magnitude of the hand-wheel step steer input.

Duration,  (real),  (deg)
Defines the time duration of the step steer input.

Rate,  (real),  (deg/s)
Defines the rate of change of the steering hand-wheel angle for ramp steer input.

Change Size,  (real),  (deg/s)
For a lane change manoeuvre defines the hand-wheel angle magnitude for each of the three steering inputs.

Lock On Time,  (real),  (s)
Sets the event time for the lock on, (first), part of the lane change manoeuvre.

Lock Off Time,  (real),  (s)
Sets the event time for the lock off, (second), part of the lane change manoeuvre.

Straighten Time,  (real),  (s)
Sets the event time for the straighten, (third), part of the lane change manoeuvre.

Steer Input,  (real),  (deg)
Defines the magnitude of the steering input of the input sine wave.

Phase,  (real),  (rad)
Defines the initial phase of the input sine wave.

Time Offset,  (real),  (s)
Defines the time delay to the start of the sine wave steering input.

Corner Radius,  (real),  (m)
Defines the radius of the steering pad.

Velocity Rate,  (real),  (m/s/s)
Sets the rate at which the vehicle speed is increased from the initial velocity.

Gain,  (real)
Defines the gain value for the steering feedback controller, used to retain the prescribed path.

Integral Feedback,  (real)
Defines the Integral value for the steering feedback controller, used to retain the prescribed path.

Differential Feedback,  (real)
Defines the Differential value for the steering feedback controller, used to retain the prescribed path.

Acceleration/Braking Events

{bmc bm65.bmp}
Solution Data  - Acceleration and Braking Events

Acceleration and Braking Event Types,  (choice)
Two acceleration/braking event types are available; Braking ‘G’ and Acceleration ‘G’.

Velocity,  (real),  (m/s)
Defines the vehicle forward speed for the analysis event.

Start Time,  (real),  (s)
Defines the point in the analysis event when the accel/braking event starts.

Lift Off Time,  (real),  (s)
Defines the point in the analysis event when the accel/braking event ends.

Lift Duration,  (real),  (s)
Defines the duration of the lift for the acceleration or braking event.

G Level,  (real),  (g)
Defines accel. or Deccel. level applied to the model.

Split Mu Factor Right,  (real)
Defines the surface mu for the right hand wheels.

Split Mu Factor Left,  (real)
Defines the surface mu for the left hand wheels.

Brake Split Front,  (real) ,  (0-1)
Defines the overall vehicle brake split by definition of the amount on the front axle.

Drive Split Front,  (real) ,  (0-1)
Defines the overall vehicle drive split by definition of the amount of drive through the front axle.

$#>KLOTUS ENGINEERING

{bmc bm66.bmp}
{bmc bm67.bmp}
{bmc bm68.bmp}