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Slowly Increasing Steer Reference Generator

Generate slowly increasing steer maneuver reference signals

Description

The Slowly Increasing Steer Reference Generator block sets the parameters that configure the slowly increasing steer maneuver.

The block generates steering, accelerator, and brake commands to conduct a linearly increasing steering maneuver. The steering command begins at the specified rate once the vehicle reaches the longitudinal velocity setpoint. After the vehicle achieves the maximum steering angle, the vehicle maintains the steering angle for a desired duration. The block then reduces the steering angle to zero at the same rate. A longitudinal controller regulates the vehicle at the prescribed speed throughout the maneuver.

Use the Steady-state solver mode parameter to specify the initial conditions for the maneuver. By default, the parameter is set to Initialize from model, and the simulation starts with the vehicle at rest at the specified initial position. If you want to start the simulation at the non-zero steady-state velocity:

  1. Set Steady-state solver mode to Solve using block parameters.

  2. On the Steady-State Solver tab, specify the initial conditions, workspace variable, and solver settings. Click Generate steady state solution.

  3. After the simulation completes, set Steady-state solver mode to Resume from a workspace variable.

  4. Set Steady-state solution to start from, ssVar to the workspace variable you specified in step 2.

  5. Run the simulation.

Ports

Input

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Bus containing vehicle feedback signals, including velocity, acceleration, and steering wheel torque.

Output

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Bus containing the vehicle reference signals, including longitudinal and lateral displacement, and steering.

Parameters

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Maneuver

Use the Steady-state solver mode parameter to specify the steady-state initial conditions for the maneuver. By default, the simulation will not find or start the simulation at the steady-state operating points.

SettingDescription
Initialize from model

Simulation starts maneuver at the simulation start time specified by Maneuver start time, t_start at longitudinal velocity of 0.

Solve using block parameters

Simulation finds the steady-state operating points using the parameters on the Steady-State Solver tab.

Resume from a workspace variable

Simulation starts at the steady-state operating points workspace variable specified by Steady-state solution to start from, ssVar.

Workspace variable containing the steady-state operating points.

Dependencies

To enable this parameter, set Steady-state initial conditions to Resume from a workspace variable.

Maneuver start time, in s.

Dependencies

To enable this parameter, set Steady-state initial conditions to Initialize from model.

Target velocity.

Units for target velocity.

Handwheel rate, in deg/s.

Maximum handwheel angle, in deg.

Steering hold, in s.

Lateral acceleration threshold, in g.

Steady-State Solver

Initial vehicle CG position along the earth-fixed X-axis, in m.

Dependencies

To enable this parameter, set Steady-state initial conditions to Solve using block parameters.

Initial vehicle CG position along the earth-fixed Y-axis, in m.

Dependencies

To enable this parameter, set Steady-state initial conditions to Solve using block parameters.

Initial vehicle yaw angle about the earth-fixed Z-axis, in rad.

Dependencies

To enable this parameter, set Steady-state initial conditions to Solve using block parameters.

Steady-state solver velocity tolerance.

Dependencies

To enable this parameter, set Steady-state initial conditions to Solve using block parameters.

Maximum simulated time to reach steady-state, in s.

Dependencies

To enable this parameter, set Steady-state initial conditions to Solve using block parameters.

Name of workspace variable containing steady-state operating points.

Dependencies

To enable this parameter, set Steady-state initial conditions to Solve using block parameters.

Version History

Introduced in R2019a