Constant Radius

Generate commands for tracking constant radius path

Since R2024b

• 

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

X — Longitudinal position vehicle center of mass

scalar

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

Data Types: double

Y — Lateral position vehicle center of mass

scalar

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

Data Types: double

psi — Vehicle yaw angle

scalar

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

Data Types: double

ay — Vehicle lateral acceleration

scalar

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

DrvRef — Driver reference data

bus

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

Signal	Description	Units
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

DrvCmd — Driver command data

bus

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

Signal		Description	Units
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.

Data Types: bus

Parameters

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, tStart [s] — Start time

2 (default) | positive scalar

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

Longitudinal velocity setpoint, velRef — Target velocity

35 (default) | positive scalar

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

Longitudinal velocity setpoint units, velRefUnit [] — Units

mph (default)

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

R — Radius to be tracked

100 (default) | positive scalar

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 position, X_o [m] — Initial longitudinal start point

0 (default) | scalar

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 position, Y_o [m] — Initial lateral start point

0 (default) | scalar

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

Initial yaw angle, psi_o [rad] — Starting heading angle

0 (default) | scalar

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

Distance between inside and outside cone boundaries, radialConeDist [m] — Radial distance between cones

6 (default) | positive scalar

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

Lateral acceleration absolute threshold, ayMax [g] — Maximum allowable lateral acceleration before simulation is stopped

0.5 (default) | positive scalar

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

Maneuver direction, steerDir — Maneuver direction

Right (default) | Left

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

Stop simulation at lateral acceleration threshold — Option to stop simulation at lateral acceleration threshold

off (default) | on

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

Instantiate 3D cones (Simulation 3D Scene Configuration required) — Option to instantiate 3D cones

off (default) | on

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