DHTransform Class Reference

Converts 4 parameter Denavit-Hartenberg notation to a 4x4 transform. More...

#include <joint.h>

List of all members.

Public Member Functions
	DHTransform (const DHTransform *d)
	DHTransform (double thval=0.0, double dval=0.0, double aval=0.0, double alval=0.0)
double	getA () const
double	getD () const
double	getTheta () const
transf	getTran (double thetaVal, double dVal) const
const transf &	getTran () const
void	setA (double q)
void	setD (double q)
void	setTheta (double q)
Private Member Functions
void	computeTran ()
	Re-computes the transform from scratch based on theta, d, a and alpha.
Private Attributes
double	a
	Translation along x-axis in mm.
double	alpha
	Rotation about x-axis in radians.
vec3	atrans
	Translation vector along the x-axis.
double	d
	Translation along z-axis in mm.
vec3	dtrans
	Translation vector along the z-axis.
double	theta
	Rotation about z-axis in radians.
transf	tr1
	Rotation transform of theta about z-axis.
transf	tr2
	Translation transform of d along z-axis.
transf	tr4TimesTr3
	Precomputed value of transform 4 times transform 3.
transf	tran
	Final transform.

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Detailed Description

Converts 4 parameter Denavit-Hartenberg notation to a 4x4 transform.

Stores the 4 Denavit-Hartenberg parameters that define a transform between the joints of a robot. Each joint has its axis aligned with the z-axis of the joint frame. The four values are theta, d, a, and alpha. Theta is the rotation about the z-axis of the current joint frame (this value is variable for revolute joints). D is the translation along the z-axis of the joint frame (this value is variable for prismatic joints). A is the transaltion along the x-axis of the joint frame, and alpha is the rotation about the x-axis.

Definition at line 58 of file joint.h.

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Constructor & Destructor Documentation

DHTransform::DHTransform	(	double	thval = 0.0,
		double	dval = 0.0,
		double	aval = 0.0,
		double	alval = 0.0
	)

Initializes the DHTransform with the 4 DH parameters.

Definition at line 62 of file joint.cpp.

DHTransform::DHTransform

(

const DHTransform *

d

)

[inline]

Definition at line 96 of file joint.h.

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Member Function Documentation

void DHTransform::computeTran

(

)

[private]

Re-computes the transform from scratch based on theta, d, a and alpha.

Definition at line 68 of file joint.cpp.

double DHTransform::getA

(

)

const [inline]

Returns the current a value.

Definition at line 107 of file joint.h.

double DHTransform::getD

(

)

const [inline]

Returns the current d value.

Definition at line 101 of file joint.h.

double DHTransform::getTheta

(

)

const [inline]

Returns the current theta value.

Definition at line 104 of file joint.h.

transf DHTransform::getTran	(	double	thetaVal,
		double	dVal
	)			const [inline]

Returns the value of this transform if thetaVal is substituted for theta and dval is substituted for d. It does not change any values within the DHTransform.

Definition at line 126 of file joint.h.

const transf& DHTransform::getTran

(

)

const [inline]

Returns the current value of this transform.

Definition at line 119 of file joint.h.

void DHTransform::setA

(

double

q

)

[inline]

Sets the a value and re-computes the transform (from scratch).

Definition at line 116 of file joint.h.

void DHTransform::setD

(

double

q

)

Sets the d value.

Sets a new d value for prismatic joints and recomputes the current value of the transform.

Definition at line 93 of file joint.cpp.

void DHTransform::setTheta

(

double

q

)

Sets the theta value.

Sets a new theta value for revolute joints and recomputes the current value of the transform.

Definition at line 106 of file joint.cpp.

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Member Data Documentation

double DHTransform::a [private]

Translation along x-axis in mm.

Definition at line 85 of file joint.h.

double DHTransform::alpha [private]

Rotation about x-axis in radians.

Definition at line 88 of file joint.h.

vec3 DHTransform::atrans [private]

Translation vector along the x-axis.

Definition at line 64 of file joint.h.

double DHTransform::d [private]

Translation along z-axis in mm.

Definition at line 82 of file joint.h.

vec3 DHTransform::dtrans [private]

Translation vector along the z-axis.

Definition at line 61 of file joint.h.

double DHTransform::theta [private]

Rotation about z-axis in radians.

Definition at line 79 of file joint.h.

transf DHTransform::tr1 [private]

Rotation transform of theta about z-axis.

Definition at line 73 of file joint.h.

transf DHTransform::tr2 [private]

Translation transform of d along z-axis.

Definition at line 70 of file joint.h.

transf DHTransform::tr4TimesTr3 [private]

Precomputed value of transform 4 times transform 3.

Definition at line 67 of file joint.h.

transf DHTransform::tran [private]

Final transform.

Definition at line 76 of file joint.h.

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

• joint.h
• joint.cpp