Defining the Mini-Maneuver Parameters
Now that you defined the three mini-maneuvers, you must define what each of the application areas and end conditions will do during the mini-maneuvers.
The application areas are steering, throttle, brake, clutch, and gear. For each application area, you define the Driving Machine control method (open, machine, or SmartDriver).
End conditions define a vehicle state that the Driving Machine uses to terminate a mini-maneuver. End conditions are extremely flexible, and let you define many types of situations that cause the vehicle state to move on to the next mini-maneuver. The following are some example end conditions:
■End conditions can have a single condition, such as time is greater than 5 seconds.
■End conditions can have a single value that must be within a tolerance over a prescribed period of time. Lateral acceleration is 0.5 g over a two-second period and within a 0.05 g tolerance.
■Multiple end conditions, such as time is greater than 5 seconds or vehicle velocity is lower than 10 kph.
■Combined end condition, such as vehicle velocity equal 100 kph (within a tolerance) and longitudinal acceleration equals 0 g (within a tolerance). Event Builder lets you group end conditions, allowing you to specify multiple conditions required to terminate a maneuver.
For more information on end conditions, see Specifying Conditions in the Adams Car online help.
To define mini-maneuver parameters for MINI_1:
1. To access the mini-maneuver property editor, double-click the name of the mini-maneuver you want to edit. In this case, MINI_1.
2. For the first mini-maneuver, the vehicle should drive in a straight line and maintain constant velocity. To achieve this, set the following parameters:
■Steering tab
Actuator Type: rotation
Control Method: machine
Steer Control: straight
The Steer Control setting enables the Driving Machine to drive the vehicle in a straight line.
■Throttle tab
Control Method: machine
Speed Control: maintain
Velocity: 27.7
The Velocity setting enables the Driving Machine to maintain the steady-state velocity that you established earlier. The Driving Machine will control the throttle to maintain this velocity much like a cruise control system.
■Braking tab
Control Method: machine
The Throttle and Brake settings control the longitudinal velocity of the vehicle.
■Gear tab
Control Method: open
Control Type: constant
Control Value: 5
Maintain the same gear specified for the static setup.
■Clutch tab
Control Method: open
Control Type: constant
Control Value: 0.0
For the first mini-maneuver, you’re using the Driving Machine for the steering and the throttle, so you can maintain the vehicle speed during straight-line driving.
The purpose of the first mini-maneuver is to reach a dynamic steady-state end condition. Although not absolutely necessary for this type of event, it helps demonstrate some important aspects of the Driving Machine. To satisfy a steady-state condition, the vehicle must be traveling a straight line (very low lateral acceleration) at a stable velocity (very low longitudinal velocity). You can use end conditions to group these two conditions together to satisfy the steady-state requirements.
To create end conditions for MINI_1:
1. Select the Conditions tab.
2. Select 
.
. 3. In the Name text box, enter END_2.
4. Select Add.
5. Modify the end conditions as follows:
■END_1
Type: lon_accel
Test : ==
Trigger Value: 0.0
Error: 0.05
Filter Time: 2.0
Delay Time: 0.0
Group Name: MINI_1
■END_2
Type: lat_accel
Test : ==
Trigger Value: 0.0
Error: 0.05
Filter Time: 2.0
Delay Time: 0.0
Group Name: MINI_1
Note that you used MINI_1 for both group names. Because END_1 and END_2 have the same Group Name, the vehicle state must satisfy both end conditions for the maneuver switch to occur.
6. Select Save.
To define mini-maneuver parameters for MINI_2:
1. Select to the left of Name label for the text box containing MINI_1.
to the left of Name label for the text box containing MINI_1. 2. Double-click on the name of the mini-maneuver, MINI_2.
3. Set the mini-maneuver parameters as follows:
■Steering tab
Actuator: rotation
Control Method: machine
Steer Control: skidpad
Entry Distance: 20.0
Radius: 120
Turn Direction: Right
These parameters will start the vehicle turning at the beginning of the second mini-maneuver.
■Throttle tab
Control Method: machine
Speed Control: maintain
Velocity: 27.7
These parameters allow the Driving Machine to maintain the straight line velocity established in MINI_1. The steering parameters established in the steering block are not modified.
■Braking tab
Control Method: machine
■Gear tab
Control Method: open
Control Type: constant
Control Value: 5
Maintain the same gear specified for the static setup.
■Clutch tab
Control Method: open
Control Type: constant
Control Value: 0.0
For the second mini-maneuver, you’re tellling the Driving Machine to make a right turn and control the vehicle on a radius of 120 m.
Next, you will create two end conditions to verify that the vehicle has reached a steady-state cornering condition.
To create end conditions for MINI_2:
1. Select the Conditions tab.
2. In the Name text box, enter END_1.
3. Select Add.
4. Create the second end condition, END_2, just as you created the first.
5. Modify the end conditions as follows:
■END_1
Condition Type: lon_accel
Test Type: ==
Trigger Value: 0.0
Error: 0.05
Filter Time: 2.0
Delay Time: 0.0
Group Name: MINI_2
■END_2
Condition Type: curvature
Test Type: ==
Trigger Value: 0.00833
Error: 0.00005
Filter Time: 2.0
Delay Time: 0.0
Group Name: MINI_2
These end conditions ensure that a radius of approximately 120 m is followed at a velocity of 100 kph.
6. Select Save.
To define mini-maneuver parameters for MINI_3:
1. Select .
. 2. Double-click on the name of the mini-maneuver, MINI_3.
3. Set the mini-maneuver parameters as follows:
■Steering tab
Actuator: rotation
Control Method: machine
Steer Control: skidpad
Entry Distance: 0.0
Radius: 120
Turn Direction: Right
These parameters maintain the radius from the previous mini-maneuver.
■Throttle tab
Control Method: machine
■Braking tab
Control Method: machine
Speed Control: lon_accel
Start Time: 1.0
Long. Acc.: - 3.0
These parameters drop the throttle at the beginning of the third mini-maneuver to zero, and control the deceleration to 3.0 m/s2.
■Gear tab
Control Method: machine
The Driving Machine controls the gear selection.
■Clutch tab
Control Method: machine
The Driving Machine controls the clutch selection.
For the third mini-maneuver, you use the Driving Machine for all vehicle activity; you want the Driving Machine to maintain the vehicle radius while at the same time braking the vehicle at 3 m/s2. You use a single end condition for the third mini-maneuver, which is velocity. You trigger the end of the simulation if the velocity is below 10 kph which is approximately 2.77 m/s.
To create the end condition for MINI_3:
1. Select the Conditions tab.
2. In the Name text box, enter END_1.
3. Select Add.
4. Modify the end condition as follows:
■END_1
Condition Type: velocity
Test Type: <<
Trigger Value: 2.77
Error: 0.01
Filter Time: 0.0
Delay Time: 0.0
5. Select Save. You can then select Cancel to close the Event Builder window.
By default, your Adams product saves the file in the current working directory. If you are not sure where the current working directory is located, do following:
■In Adams Car, from the File menu, select Select Directory.
This displays a dialog that shows the current working directory.