MV-8003: Gear and Clutch Control

In this tutorial, you will learn how to interface gear clutch control for vehicles with manual transmission.

Gear clutch controller
The Engine speed based shift controller upshifts whenever engine speed goes above the upshift RPM, and it downshifts when the engine speed goes below the downshift RPM. The Gear shift controller also controls the throttle and clutch signal as shown in the figure below.
Figure 1.

Assemble the Vehicle

In this step, you will assemble the vehicle using the Assembly Wizard.

  1. Start a new MotionView session.
  2. Ensure the MBD-Vehicle Dynamics Tools preference file loaded is for all of the MotionView functionality of the Advanced Driver to work properly.
    Figure 2.
    Figure 3.
  3. From the menu bar, select Model > Assembly Wizard.
    In Script an Open Loop Acceleration Event, a linear torque map powertrain will be used to avoid the complexity of adding controllers for gear and clutch.
    Figure 4.
  4. Select the Full vehicle with advanced driver option.
    This takes care of all the dependencies of the advanced driver.
    Figure 5.
  5. Click Next.
  6. Choose the default selections in the following Assembly Wizard pages.
    Page Label Selection Default (Yes/No)
    1 Model type Full vehicle with driver No
    2 Driveline configuration Front wheel drive Yes
    3 Instrumentation Instrumentation Yes
    3 Front subframe None Yes
    3 Front suspension Frnt macpherson susp (1 pc. LCA) Yes
    3 Steering linkages Rackpin steering Yes
    3 Rear subframe None Yes
    3 Rear suspension Rear quadlink susp Yes
    3 Powertrain IC engine friction clutch (manual) No
    3 Signal generator Driver signal generator Yes
    3 Tires Auto Tires Yes
    4 Steering column Steering column 1 (not for Abaqus) Yes
    4 Steering boost None Yes
    5 Front struts Frnt strut (with inline jts) Yes
    5 Front stabilizer bars Frnt stabar with links Yes
    5 Rear struts Rear strut (with inline jts) Yes
    5 Rear stabilizer bars Rear stabar with links Yes
    6 Front jounce bumpers None Yes
    6 Front rebound bumpers None Yes
    6 Rear jounce bumpers None Yes
    6 Rear rebound bumpers None Yes
    7 Disk brakes Disk brakes Yes
    7 Front driveline Independent fwd Yes
    8 Driver System Altair Driver Yes
    9   Next No
    10   Finish No

Add Driver Analysis

In this step, you will use the Task Wizard to load the driver analysis.

  1. From the menu bar, select Analysis > Task Wizard.
    Figure 6.
  2. Select AltairDriverFile from the Type drop-down menu.


    Figure 7.
    Tip:

    Selecting (Altair Driver icon) will open up the Altair Driver panel. This automatically resolves all of the vehicle attachments for the Altair Driver.

    Figure 8.

    Selecting the AltairDriverFile 0 will open up the driver event panel. Selecting the Event Editor button will open the Altair Driver File dialog.

The Altair Advanced Driver is added to the browser tree.

Specify Vehicle Parameters

In this step, you will specify parameters for the vehicle.

Feedforward controllers require vehicle parameters because they model the vehicle. Vehicle parameters do not need to be precise. Most of the vehicle parameters required by the driver can be automatically calculated from the vehicle model.
Specify the parameters for the vehicle.

Write an Altair Driver File Driving Event

In this step, you will create a constant radius with constant velocity event, a straight line acceleration event, and a path as a table of cartesian coordinates of centerline points event.

Driver requires an event script or the Altair driver file (ADF) to run any driving event. ADF can be edited using any text editor or by clicking the Edit Driver File button on the driver panel.

Velocity Profile Following with Gear and Clutch Controller

In this step, you will modify the ADF written in Path as a Table of Cartesian Coordinates of Centerline Points Event of MV-8001: Path and Velocity Following and incorporate a gear and clutch controller.

  1. Open any text editor and copy and paste the following text into it.
    Important: All blank lines must be removed prior to saving the file.
    Tip: Read through the comments for a better understanding on what is written in the ADF.
    $-----------------------------------------------------------------ALTAIR_HEADER
[ALTAIR_HEADER]                                                                             
FILE_TYPE 		= 'ADF'                                                                  
FILE_VERSION 	= 1.0                                                                
FILE_FORMAT 	= 'ASCII'                                                            
$--------------------------------------------------------------------------UNITS
[UNITS]                                                                                     
(BASE)                                                                                      
{length  force      	angle       mass   time}                                               
'meter'   'newton'   	'radians'  'kg'      'sec'                                              
$--------------------------------------------------------------------VEHICLE_IC
[VEHICLE_INITIAL_CONDITIONS]                                                                 
VX0 = -20.0                                                                                     
VY0 = 0.0                                                                                    
VZ0 = 0.0                                                                                    
$--------------------------------------------------------------STEERING_STANDARD
[STEER_STANDARD]                                                                            
MAX_VALUE 			= 3.141593                                                         
MIN_VALUE 			= -3.141593                                                         
SMOOTHING_FREQUENCY 	= 10.0
INITIAL_VALUE 		= 0.0
$--------------------------------------------------------------THROTTLE_STANDARD
[THROTTLE_STANDARD]                                                                         
MAX_VALUE 			= 1.0                                                      
MIN_VALUE 			= 0.00                                                      
SMOOTHING_FREQUENCY 	= 10.0
INITIAL_VALUE 			= 0.2                                        
$---------------------------------------------------------------BRAKING_STANDARD            
 [BRAKE_STANDARD]                                                                            
MAX_VALUE 			= 1.0                                                         
MIN_VALUE 			= 0.0                            
SMOOTHING_FREQUENCY 	= 10.0                             
INITIAL_VALUE 			= 0.0 
$---------------------------------------------------------------GEAR_STANDARD
[GEAR_STANDARD]
MAX_VALUE           = 6
MIN_VALUE           = 1
INITIAL_VALUE       = 1
$---------------------------------------------------------------CLUTCH_STANDARD
[CLUTCH_STANDARD]
MAX_VALUE           = 1
MIN_VALUE           = 0
SCALING_FACTOR      = 1
INITIAL_VALUE       = 0.0
$-----------------------------------------------------------------MANEUVERS_LIST 
[MANEUVERS_LIST]                                                                            
{ name       		simulation_time  h_max  print_interval}                         
'MANEUVER_1'		10.0                     0.01     0.01                                    
$---------------------------------------------------------------------MANEUVER_1            
[MANEUVER_1]
TASK = 'STANDARD'                                                                           
(CONTROLLERS)                                                                               
{DRIVER_SIGNAL  	PRIMARY_CONTROLLER 	ADDITIONAL_CONTROLLER}      
 STEER                   	FEEDFORWARD_STEER	  		NONE                                
 THROTTLE             	FEEDFORWARD_TRACTION	  		NONE                            
 BRAKE                   	FEEDFORWARD_TRACTION 			NONE                                
 GEAR 			GEAR_CLUTCH_CONTROL			NONE
 CLUTCH			GEAR_CLUTCH_CONTROL			NONE
$---------------------------------------------------------STEER
 [FEEDFORWARD_STEER]                                                                      
TAG 			= 'FEEDFORWARD'
LOOK_AHEAD_TIME 	= 0.5
$Instruction to the driver that the path is of type DDF 
PATH 			= 'DDF' 
$Path of the ddf file, data lies in same folder in file named snet.ddf
FILE 			= 'snet.ddf'
$--------------------------------------------------THROTTLE & BRAKE             
[FEEDFORWARD_TRACTION]                                                                      
TAG 			= 'FEEDFORWARD'
TYPE 			= 'FOLLOW_VELOCITY'
LOOK_AHEAD_TIME 	= 0.5
DEMAND_SIGNAL 	= 'DEMAND_SPEED'
$---------------------------------------------------------DEMAND_SPEED
$Block containing all the information about the acceleration profile to be followed             
[DEMAND_SPEED]                                                                      
TYPE 			= 'CURVE'
$Velocity profile information is in the file snet.ddf in the same folder
$Velocity profile is defined under the column name DV in the DDF
${X 	Y 	Z 	DV}
FILE			= 'snet.ddf'
DEMAND_VECTOR	= 'DV'
$Gear clutch controller
[GEAR_CLUTCH_CONTROL]
TAG = 'ENGINE_SPEED'
(GEAR_SHIFT_MAP)
{G  US      DS      CT      CRT     TFD     TFT     CFT     TRD     TRT}
1   650     285     0.45    0.05    0.1     0.1     0.05    0.05    0.05
2   650     285     0.45    0.05    0.1     0.1     0.05    0.05    0.05
3   650     285     0.45    0.05    0.1     0.1     0.05    0.05    0.05
4   650     285     0.45    0.05    0.1     0.1     0.05    0.05    0.05
5   650     285     0.45    0.05    0.1     0.1     0.05    0.05    0.05
  2. Click to run the simulation.
  3. Observe the results.