Straight Maneuver Reference Generator

Generate straight maneuver reference signals

Since R2021a

Description

The Straight Maneuver Reference Generator block generates accelerator and brake commands to conduct a straight line maneuver for the Braking Test. The acceleration begins at the specified rate until the vehicle achieves the longitudinal velocity setpoint. The vehicle controller maintains the longitudinal velocity setpoint for the specified time or distance. The controller then decelerates the vehicle.

Use the Maneuver Parameters to specify the maneuver start time, velocity setpoint, acceleration, and deceleration.

Optionally, on the Tracking Parameters tab, select Enable fault tracking before braking. Use the parameters to specify fault conditions before braking during a split-mu test. If the vehicle speed, steering angle, or yaw rate is not within the allowable range before braking, the block sets a fault condition. The default values represent compliance with ISO 14512¹.

Examples

Braking Test Reference Application

Simulate a full vehicle dynamics model undergoing a braking test. Use for vehicle dynamics ride and handling analysis and chassis controls development, including the dynamic response to split-mu tests.

Open Script

Ports

Input

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VehFdbk — Vehicle feedback
`Bus`

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

Output

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Ref — Vehicle reference signals
`Bus`

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

Parameters

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Maneuver Parameters

Maneuver start time, t_start — Start time
`2` (default) | `scalar`

Maneuver start time, in s.

Longitudinal acceleration at t_start, ax — Longitudinal acceleration
`0.5` (default) | `scalar`

Longitudinal acceleration at maneuver start, in g.

Longitudinal velocity reference, xdot_r — Longitudinal velocity reference, xdot_r
`20` (default) | `scalar`

Longitudinal velocity reference, xdot_r, in units specified by Units of velocity, xdotUnit.

Units of velocity, xdotUnit — Units
`m/s` (default) | `km/h` | `char`

Units of velocity.

Brake pedal actuation — Deceleration trigger
`Longitudinal displacement` (default) | `Time`

Method to start deceleration.

Select Longitudinal displacement to specify a displacement to start decelerating the vehicle.

Select Time to specify a time to start decelerating the vehicle.

Longitudinal displacement of vehicle CG, x_brake — Displacement
`200` (default) | `scalar`

Longitudinal displacement of vehicle CG to start deceleration, in m.

Dependency

To enable this parameter, set Brake pedal actuation to Longitudinal displacement.

Brake actuation time, t_brake — Time
`15` (default) | `scalar`

Time to start deceleration, in s.

Dependency

To enable this parameter, set Brake pedal actuation to Time.

Longitudinal deceleration at t_brake, ax_dec — Deceleration
`1` (default) | `scalar`

Longitudinal deceleration at braking time, in g.

Transport delay buffer size, BufferSize — Buffer
`4096` (default) | `scalar`

Transport delay buffer size.

Select handwheel angle to 0 deg after braking — Selection
`on` (default) | `off`

Set the handwheel angle to 0 after braking.

Tracking Parameters

Enable fault tracking before braking — Enable fault tracking
`on` (default) | `off`

Select this parameter to enable fault tracking before braking. Use the parameters to specify fault conditions before braking during a split-mu test. If the vehicle speed, steering angle, or yaw rate is not within the allowable range before braking, the block sets a fault condition. The default values represent compliance with ISO 14512¹.

Longitudinal velocity and mean longitudinal velocity, xdot_rmax — Maximum velocity tolerance
`1` (default) | `scalar`

The longitudinal velocity and mean longitudinal velocity tolerance. If the longitudinal velocity or mean longitudinal velocity exceeds the allowable range, the block sets a fault condition.