robLSPB Class Reference

Linear Segments with Parabolic Blends trajectory generator. More...

#include <robLSPB.h>

Public Types
enum	CoordinationType { LSPB_NONE , LSPB_DURATION }

Public Member Functions
	robLSPB (void)
	robLSPB (const vctDoubleVec &start, const vctDoubleVec &finish, const vctDoubleVec &velocity, const vctDoubleVec &acceleration, const double startTime=0.0, const CoordinationType coordination=LSPB_NONE)
	~robLSPB ()
void	Set (const vctDoubleVec &start, const vctDoubleVec &finish, const vctDoubleVec &velocity, const vctDoubleVec &acceleration, const double startTime=0.0, const CoordinationType coordination=LSPB_NONE)
	Set start and finish position as well as desired maximum velocities and accelerations. Start time is provided as a convenience so that future calls to Evaluate can use absolute time. All vectors must match the start position size.
void	Evaluate (const double time, vctDoubleVec &position, vctDoubleVec &velocity, vctDoubleVec &acceleration)
void	Evaluate (const double time, vctDoubleVec &position)
double &	StartTime (void)
	Return start time.
double	Duration (void) const
	Return duration.

Protected Attributes
bool	mIsSet
size_t	mDimension
double	mStartTime
double	mDuration
CoordinationType	mCoordination
vctDoubleVec	mStart
vctDoubleVec	mFinish
vctDoubleVec	mVelocity
vctDoubleVec	mAcceleration
vctDoubleVec	mAccelerationTime
vctDoubleVec	mFinishTime
vctDoubleVec	mTimeScale
vctDoubleVec	mTemp

Detailed Description

Linear Segments with Parabolic Blends trajectory generator.

This trajectory generator is based on LSPB as described in "Robotics: Basic Analysis and Design" by William A. Wolovich. The trajectory generated corresponds to maximum acceleration until maximum velocity is reached followed by maximum deceleration until final position is reached. Desired velocities and accelerations are defined as strictly positive numbers.

It can operate on multiple joints and the user must choose how to coordinate the motion. Current options to coordinate the joint trajectories are LSPB_NONE and LSPB_DURATION. With LSPB_NONE, each joint moves as fast as possible. With LSPB_DURATION, the trajectories are scaled so they start and end at the same time based on the slowest joint. It's important to note that acceleration, constant velocities and decelaration phases are not coordinated.

If the user attempt to evaluate a point before the start time, the generator returns the start point. For any time after the end time, the generator returns the end point.

Member Enumeration Documentation

CoordinationType

enum robLSPB::CoordinationType

Enumerator
LSPB_NONE
LSPB_DURATION

Constructor & Destructor Documentation

robLSPB() [1/2]

robLSPB::robLSPB

(

void

)

robLSPB() [2/2]

robLSPB::robLSPB	(	const vctDoubleVec &	start,
		const vctDoubleVec &	finish,
		const vctDoubleVec &	velocity,
		const vctDoubleVec &	acceleration,
		const double	startTime = 0.0,
		const CoordinationType	coordination = LSPB_NONE )

~robLSPB()

robLSPB::~robLSPB ( )

inline

Member Function Documentation

Duration()

double robLSPB::Duration

(

void

)

const

Return duration.

Evaluate() [1/2]

void robLSPB::Evaluate	(	const double	time,
		vctDoubleVec &	position )

Evaluate() [2/2]

void robLSPB::Evaluate	(	const double	time,
		vctDoubleVec &	position,
		vctDoubleVec &	velocity,
		vctDoubleVec &	acceleration )

Set()

void robLSPB::Set	(	const vctDoubleVec &	start,
		const vctDoubleVec &	finish,
		const vctDoubleVec &	velocity,
		const vctDoubleVec &	acceleration,
		const double	startTime = 0.0,
		const CoordinationType	coordination = LSPB_NONE )

Set start and finish position as well as desired maximum velocities and accelerations. Start time is provided as a convenience so that future calls to Evaluate can use absolute time. All vectors must match the start position size.

Parameters

start	Start position
finish	Finish position
velocity	Desired maximum velocity \accelerations Acceleration (and deceleration) used to reach maximum velocity

StartTime()

double & robLSPB::StartTime

(

void

)

Return start time.

Member Data Documentation

mAcceleration

vctDoubleVec robLSPB::mAcceleration

protected

mAccelerationTime

vctDoubleVec robLSPB::mAccelerationTime

protected

mCoordination

CoordinationType robLSPB::mCoordination

protected

mDimension

size_t robLSPB::mDimension

protected

Number of degrees of freedom

mDuration

double robLSPB::mDuration

protected

Max of all finish times

mFinish

vctDoubleVec robLSPB::mFinish

protected

mFinishTime

vctDoubleVec robLSPB::mFinishTime

protected

mIsSet

bool robLSPB::mIsSet

protected

To ensure we don't evaluate if the parameters are not set

mStart

vctDoubleVec robLSPB::mStart

protected

mStartTime

double robLSPB::mStartTime

protected

Start time, used to evaluate relative to 0

mTemp

vctDoubleVec robLSPB::mTemp

protected

mTimeScale

vctDoubleVec robLSPB::mTimeScale

protected

mVelocity

vctDoubleVec robLSPB::mVelocity

protected

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The documentation for this class was generated from the following file:

• tmp/cisst-saw/cisst/cisstRobot/robLSPB.h