Figure 4.22 Full vehicle models
4.3.6 Testing the Full Vehicle
1. Creating Motion and Torque
Select
the Rotational Joint Motion tool
.
Select the Cylindrical Joint between the Steering_wheel
and the Chassis, to create the Rotational Joint Motion
on the Steering_wheel. Modify the motion equation: step(time,
1,0,2,100d), see Fig.4.23.
Figure 4.23 Joint Motion Dialog Box
Select the Torque tool
.
Select Two Bodies, see Figure 4.23. Select the Left_RCA
as master body, then select the TIRE_3 as slave body,
select design point of the Left_RCA_outer as master point,
select design point of the RL_Wheel_center as slave point, to
create the drive torque on the Left Tire. Modify the torque
equation: step(time, 0,0,1,-11000)+step(time,60,-30000,120,-150000),
see Fig.4.25.
Figure 4.24 Figure 4.25 Modify Torque Dialog Box
Follow above steps to create the drive torque on the Right Tire between the Right_RCA and the TIRE_4.
2. Creating curves on the vehicle characteristic
1) From the Build menu, point to Measure, point to Function, and then select New. The Function Builder dialog box appears.
2) In the Measure Name text box, enter the measure name as Radius. Units select Length(m), then edit the function expression of Radius with Function Builder.
The function expression of Radius:
(VM(.jeep.chassis.cm)/WY(.jeep.chassis.cm))/1000
3) From the Build menu, point to Measure, point to Function, and then select New. The Function Builder dialog box appears.
4) In the Measure Name text box, enter the measure name as Velocity. Units select Length(m), then edit the function expression of Velocity with Function Builder.
The function expression of Velocity:
SQRT(VX(.JEEP.Chassis.cm)**2+VZ(.JEEP.Chassis.cm)**2)*3.6/1000
3. Simulation
1) Select the Simulation tool .
2) Set up a simulation with an end time of 120 second and Step Size of 0.01.
3) Select the Simulation Start tool .
4) To return to the initial model configuration, select the Reset tool .
The curves on the vehicle characteristic appear during the simulation, as shown next:
Figure 4.26 The curve of the Kingpin_Inclination vs time
Figure 4.27 The curve of the velocity vs time
Figure 4.28 The curve of the Kingpin_Inclination vs velocity
Figure 4.29 The motion trace of the vehicle mass center
Section II - ADAMS/Car
5 Introduce adams/Car
This chapter introduces you to ADAMS/Car and explains how you can benefit from using it. It also explains how you can learn more about ADAMS/Car and introduces the tutorials that we’ve included in this guide to help you become familiar with ADAMS/Car.
5.1 What is adams/Car?
ADAMS/Car is a specialized environment for modeling vehicles. It allows you to create virtual prototypes of vehicle subsystems, and analyze the virtual prototypes much like you would analyze the physical prototypes.
The ADAMS/Car model hierarchy is comprised of the following components, which are stored in databases:
Templates - Are ADAMS/Car models built in ADAMS/Car Template Builder by users who have expert privileges. Templates are parameterized and generally are topological representations of vehicle subsystems, which can include front suspensions, brakes, chassis, and so on.
You save templates in ASCII or binary format.
Subsystems - Are based on ADAMS/Car templates and allow standard users to change the parametric data of the template. For example, you can change the location of hardpoints, modify parameter variables, and so on.
You save subsystems in ASCII format.
Assemblies - Are comprised of subsystems that can be grouped together to form suspension assemblies, full-vehicle assemblies, and so on.
You save assemblies in ASCII format.
ADAMS/Car has two modes:
Standard Interface - You use it when working with existing templates to create and analyze assemblies of suspensions and full vehicles. Both standard users and expert users can use ADAMS/Car Standard Interface.
Template Builder - If you have expert user privileges, you use ADAMS/Car Template Builder to create new templates for use in ADAMS/Car Standard Interface.
When you create a new component in the Template Builder, ADAMS/Car automatically adds a prefix based on the entity type and the symmetry. ADAMS/Car uses a naming convention to let you easily determine an entity’s type from the entity’s name.