Swept Sine Reference Generator

Generate swept-sine maneuver reference signals

Since R2019a

Description

The Swept Sine Reference Generator block sets the parameters that configure the swept-sine maneuver. Once the vehicle reaches the target longitudinal velocity, the block generates a sinusoidal steering command with linearly increasing frequency, up to the maximum specified in the allotted time.

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:

Set Steady-state solver mode to Solve using block parameters.
On the Steady-State Solver tab, specify the initial conditions, workspace variable, and solver settings. Click Generate steady state solution.
After the simulation completes, set Steady-state solver mode to Resume from a workspace variable.
Set Steady-state solution to start from, ssVar to the workspace variable you specified in step 2.
Run the simulation.

Examples

Swept-Sine Steering Reference Application

Simulate a full vehicle dynamics model undergoing a swept sine steering maneuver. Use for vehicle dynamics ride and handling analysis and chassis controls development, including the dynamic steering response.

Open Example

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

Steady-state solver mode — Start maneuver from steady-state
`Initialize from model` (default) | `Solve using block parameters` | `Resume from a workspace variable`

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.

Setting	Description
`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.

Steady-state solution to start from, ssVar — Workspace variable with steady-state operating points
`char`

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, t_start — Start time
`scalar`

Maneuver start time, in s.

Dependencies

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

Longitudinal velocity setpoint, xdot_ref — Target velocity
`50` (default) | `scalar`

Target velocity.

Longitudinal speed setpoint units, xdotUnit — Units
`mph` (default)

Units for target velocity.

Steering amplitude, theta_hw — Steering amplitude
`scalar`

Sinusoidal steering amplitude, in deg.

Final frequency, theta_hw_final — Final frequency
`scalar`

Cut off frequency to stop the maneuver, in Hz.

Swept time, t_sweep — Sweep time
`scalar`

Sweep time, in s.

Steady-State Solver