Adams/SmartDriver

Adams/SmartDriverAdams/SmartDriver

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Adams/SmartDriverAdams/SmartDriver is an advanced driver simulator that can bring a vehicle to its dynamic limits or near targets you define. You must supply a path over which the vehicle will be driven and a target (either vehicle limits or user-defined limits). The typical Adams/SmartDriver application is for a single mini-maneuver for which you require maximum or target performance.

Adams/SmartDriver lets you improve handling, durability, or ride performance of the verhicle model based on predicted performance Adams/SmartDriver computes. It gives you the ability to investigate system-level dynamics of the vehicle model, while requiring minimal setup.

The following figure summarizes the Adams/SmartDriver internal architecture:

Adams/SmartDriver calculates the speed profile using a built-in quasi-static solver. This solver can take into account tire limits, engine and brake system limits, as well as full load transfer and aerodynamics.

The internal solver is a fast simplified vehicle model, with rigid suspensions. It inherits all vehicle data (initial conditions, geometry, inertial values, tires, and so on) from the full model, and integrates forward in time dynamics, taking into account inertial effects, load transfer, aerodynamics, and driver demands. Powertrain and tires are fully compliant with Adams (PAC2002 and PAC96 tire models are fully compliant; PAC94 and PAC89 are supported for compatibility).

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You provide Adams/SmartDriver with a path and start a dynamic simulation. Adams/SmartDriver inherits all vehicle data from the full Adams vehicle model, and performs one of the following two tasks:

• Vehicle Limits - Adams/SmartDriver iteratively performs the following steps:

1. Calculates a limit (maximum performance) speed profile over the reference path.

2. Checks the speed profile using a fast, simplified vehicle model (driven by the same Driving Machine as the full Adams model) to take into account transient dynamics during tracking of the speed generated by the quasi-static solver.

3. Performs an analysis of vehicle states over the trajectory, searching for path locations that cannot be traveled with the current target speed during the full dynamic simulation. If Adams/SmartDriver finds an unfeasible point, it notifies the lap-time simulator, which modifies the speed profile and repeats the entire procedure until it finds all feasible points.

• Used-Defined Limits - If you choose a user-defined vehicle limits maneuver, Adams/SmartDriver acts in a slightly different way, as explained next. First, you must provide four additional parameters:

• • % of maximum longitudinal acceleration

• • % of maximum longitudinal deceleration

• • % of maximum lateral acceleration during a left turn

• • % of maximum lateral acceleration during a right turn

Then, Adams/SmartDriver calculates a speed profile that brings the vehicle over those limits, as follows:

1. Calculates four additional limits using the parameters specified and theoretical limits of the vehicle. First, Adams/SmartDriver finds the vehicle limits, and then, using the given percentages, it calculates the actual limits.

2. Taking into account both vehicle limits and user-defined ones, Adams/SmartDriver creates a speed profile that brings the vehicle to those limits.

Adams/SmartDriverUsing Adams/SmartDriver

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Using Adams/SmartDriverTo run a SmartDriver analysis you need to provide a model drive and path to follow. In addition, you can select two different cruising modes:

• vehicle_limits - Drive the vehicle at maximum speed possible

• user_defined - Use only a defined percentage of the vehicle capabilities

Submitting an Adams/SmartDriver analysis is the easiest way to use the SmartDriver dialog box. To submit an analysis, from the Simulate menu, point to Full-Vehicle Analysis, and then select

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Adams/SmartDriver. The following example shows how to run an ISO lane change maneuver using the vehicle limits option.

Learn more about the dialog box.

In the example above, the initial speed and gear are set to 160 km/hr and 5th gear. Because the path orientation is already aligned to the vehicle (that is, the vehicle travels along negative X, as does the path in the .drd file), the path Course Marker option is set to Rearward.

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Adams/Solver automatically generates path graphics using the path description defined in the course file.

You can run a target performance analysis by changing the Smart Driver Task to user_defined and specifying desired performance scale factors for driving, braking, and right-hand and left-hand turns.

Modifying the Event FileThe SmartDriver analysis submission produces an event file in XML format. You can open this file in Event Builder to refine parameters that are not accessible using the SmartDriver analysis dialog box, for example, gear shift timing parameters or the RPM control.

Executing an Event File Dialog BoxYou can execute the modified event file using the File Driven Events dialog box. To execute an event, From the Simulate menu, point to Full-Vehicle Analysis, and then select File Driven Events.

The following example shows how to run an event file. In this case, no automatic generation of the path graphics (for example of a drd file) occurs.

Learn more about the dialog box.

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In this mode, you can submit multiple SmartDriver-based analyses with a single click. Modifying the event file you can, for example, switch the target path to a modified version with reduced curvature peaks (corner cutting), run a new analysis, and then compare the two results:

Obviously, when the path is smoother, SmartDriver can drive the vehicle faster.

Adams/SmartDriverUsing Adams/SmartDriver

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