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Constant Radius

Generate commands for tracking constant radius path

Since R2024b

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  • Constant radius block icon

Libraries:
Vehicle Dynamics Blockset / Vehicle Scenarios / Drive Cycle and Maneuvers

Description

The Constant Radius block generates an open-loop longitudinal velocity reference and a reference pose using vehicle feedback to track a constant radius path, which is helpful to characterize a vehicle’s roll and understeer responses, usually at various speeds. You can use these references directly with the Predictive Driver block with the Lateral control type, controlTypeLat parameter set to Stanley. You can also vary the radius and direction of travel and optionally stop the simulation at a specified lateral acceleration limit.

Ports

Input

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Longitudinal position of the vehicle center of mass in the global coordinate frame, specified as a scalar, in m.

Data Types: double

Lateral position of the vehicle center of mass in the global coordinate frame, specified as a scalar, in m.

Data Types: double

Vehicle yaw angle with respect to the global coordinate system, specified as a scalar, in m.

Data Types: double

Vehicle lateral acceleration needed to stop the simulation, specified as a scalar, in gee.

Dependencies

To enable this parameter, select Stop simulation at lateral acceleration threshold.

Data Types: double

Output

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Driver reference data, returned as a bus containing these block values.

SignalDescriptionUnits

LngRef

Longitudinal reference velocity

m/s

LtrRef

Lateral reference displacement

m

XRef

Vehicle global longitudinal reference position

m

YRef

Vehicle global lateral reference position

m

PhiRef

Vehicle global yaw reference position

rad

CurvRef

Reference path curvature

1/m

CurvGradRef

Reference path curvature gradient

1/m^2

Data Types: bus

Driver command data, returned as a bus containing these block values.

SignalDescriptionUnits

SteerCmd

EnblSteerCmd

Boolean signal used to override driver model steering commands

one

SteerCmd

Handwheel angle

one

SteerZero

Boolean signal used to override driver model steering commands with zero when value is true

one

SteerHld

Boolean signal used to hold the current driver model steering output when true

one

AccelCmd

EnblAccelCmd

Boolean signal used to override driver model acceleration commands

one

AccelCmd

Normalized accelerator input

one

AccelHld

Boolean signal used to hold the current driver model acceleration output when true

one

AccelZero

Boolean signal used to override driver model acceleration commands with zero when value is true

one

DecelCmd

EnblDecelCmd

Boolean signal used to override driver model deceleration commands

one

DecelCmd

Normalized decelerator or brake input

one

DecelHld

Boolean signal used to hold the current driver model deceleration output when true

one

DecelZero

Boolean signal used to override driver model deceleration commands with zero when value is true

one

HndBrkCmd

Normalized handbrake or park brake input

one

TransCmd

TransModeCmd

Command to specify the transmission mode

one

GearCmd

Command to specify manual gear number or automatic transmission shifter position

one

UpShiftCmd

Command to upshift

one

DwnShiftCmd

Command to downshift

one

ClutchCmd

Normalized clutch open command for manual transmissions

one

Note

By default, the TransCmd bus is not actively used. Use a Bus Assignment block to override the TransCmd bus to customize and extend the scenario.

Block diagram where the Bus Assignment block overrides the TransCmd output from the Constant Radius block.

Data Types: bus

Parameters

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To edit block parameters interactively, use the Property Inspector. From the Simulink® Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Maneuver start time, in s.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: tStart
Values: 2 (default) | positive scalar
Data Types: double

Target velocity.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: velRef
Values: 35 (default) | positive scalar
Data Types: double

Units for target velocity.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: velRefUnit
Values: mph (default) | character vector
Data Types: character vector

Radius to be tracked, in m.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: R
Values: 100 (default) | positive scalar
Data Types: double

Initial longitudinal start point of the circular reference in global coordinates, in m.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: X_o
Values: 0 (default) | scalar
Data Types: double

Initial lateral start point of the circular reference in global coordinates, in m.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: Y_o
Values: 0 (default) | scalar
Data Types: double

Starting heading angle of the circular reference in global coordinates, in rad.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: psi_o
Values: 0 (default) | scalar
Data Types: double

Radial distance between cones, in m.

Dependencies

To enable this parameter, select Instantiate 3D cones (Simulation 3D Scene Configuration required).

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: radialConeDist
Values: 6 (default) | positive scalar
Data Types: double

Maximum allowable lateral acceleration before the simulation is stopped, in g.

Dependencies

To enable this parameter, select Stop simulation at lateral acceleration threshold.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: ayMax
Values: 0.5 (default) | positive scalar
Data Types: double

Set the maneuver direction as Right or Left.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: steerDir
Values: Right (default) | Left
Data Types: character vector

Select this parameter to stop the simulation at the lateral acceleration threshold.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: ayStop
Values: off (default) | on
Data Types: character vector

Select this parameter to instantiate 3D cones. The Simulation 3D Scene Configuration block is required.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

To get the block parameter value programmatically, use the get_param function.

Parameter: use3DCones
Values: off (default) | on
Data Types: character vector

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2024b

See Also