Tjoint Struct Reference

Relation between two links. More...

#include <joint.h>

Collaboration diagram for Tjoint:

Data Fields
unsigned int	t
unsigned int	id
unsigned int	linkID [2]
Tlink *	link [2]
double	points [6][3]
double	normals [3][3]
Tinterval	normRange
boolean	hasLimits
boolean	avoidLimits
double	avoidLimitsWeight
Tinterval	range
Tinterval	range2
double	vrange [2][3]
unsigned int	obj3d
double	rad
double	length
Tcolor	color
THTransform	trs

Detailed Description

Constraints on the relative moments between two links.

We store the pointers to the links related by the joint and also their identifiers. This is so because the identifiers are not stored in the links itselfs (they are the indexes of the links as stored in the mechanism).

Todo:: Right now only prismatic, spherical, revolute, universal and spherical-spherical joints are defined. Although it is not urgent, we have to define more types of joints: CYL_JOINT (cylindrical joint), and HEL_JOINT (helical joint).
To define a new type of joint, we have to define a new constructor, to to extend the GenerateJointEquations and the GenerateJointRangeEquations functions.

See also:: joint.h, joint.c.

Definition at line 129 of file joint.h.

Field Documentation

unsigned int Tjoint::t

Type of joint: REV_JOINT (revolute joint), PRS_JOINT (prismatic joint), FREE_JOINT (free joint).

Definition at line 130 of file joint.h.

Referenced by CopyJoint(), GenerateJointEquations(), GenerateJointEquationsInBranch(), GenerateJointRangeEquations(), GetJointDOF(), GetJointLength(), GetJointMaxCoordinate(), GetJointTransform(), GetJointType(), MoveJoint(), NewFixJoint(), NewFreeJoint(), NewInPatchJoint(), NewPrismaticJoint(), NewRevoluteJoint(), NewSphericalJoint(), NewSphSphJoint(), NewUniversalJoint(), PlotJoint(), and RegenerateJointSolution().

unsigned int Tjoint::id

Unique identifier assigned to the joint. This is used to generate unique names for the variables associated with the joint. Using the names of the links is informative but not enough since we can have several joint between the same couple of links.

Definition at line 133 of file joint.h.

Referenced by CopyJoint(), GenerateJointEquations(), GenerateJointEquationsInBranch(), GenerateJointRangeEquations(), GetJointID(), NewFixJoint(), NewFreeJoint(), NewInPatchJoint(), NewPrismaticJoint(), NewRevoluteJoint(), NewSphericalJoint(), NewSphSphJoint(), NewUniversalJoint(), and RegenerateJointSolution().

unsigned int Tjoint::linkID[2]

Identifiers of the links constrained by the joint.

Definition at line 138 of file joint.h.

Referenced by CopyJoint(), GenerateJointEquations(), GenerateJointEquationsInBranch(), GenerateJointRangeEquations(), JointFromID(), JointToID(), MoveJoint(), NewFixJoint(), NewFreeJoint(), NewInPatchJoint(), NewPrismaticJoint(), NewRevoluteJoint(), NewSphericalJoint(), NewSphSphJoint(), and NewUniversalJoint().

Tlink* Tjoint::link[2]

Pointers to the links constrained by the joint.

Definition at line 139 of file joint.h.

Referenced by CopyJoint(), GenerateJointEquations(), GenerateJointEquationsInBranch(), GenerateJointRangeEquations(), JointFrom(), JointTo(), MoveJoint(), NewFixJoint(), NewFreeJoint(), NewInPatchJoint(), NewPrismaticJoint(), NewRevoluteJoint(), NewSphericalJoint(), NewSphSphJoint(), NewUniversalJoint(), and RegenerateJointSolution().

double Tjoint::points[6][3]

In gneral, a joint constraints the relative motion between links stablishing relations between a vector defined in the first link reference frame and a vector defined in the second link reference frame.
In this case 4 points are used to define the two vectors (two points in the frame of reference of the first link and two points in that of the second link).
In some cases less than four points are necessary (for instance, for SPH_JOINTS only one point in each reference frame is required).
In other cases (for instance the IN_PATCH joint) 6 points are necessary: two to define the point and normal in the first link and 4 to define the patch in the second link.

Definition at line 141 of file joint.h.

Referenced by CopyJoint(), GenerateJointEquations(), GenerateJointEquationsInBranch(), GetJointPoint(), MoveJoint(), NewFixJoint(), NewFreeJoint(), NewInPatchJoint(), NewPrismaticJoint(), NewRevoluteJoint(), NewSphericalJoint(), NewSphSphJoint(), and NewUniversalJoint().

double Tjoint::normals[3][3]

In general, normalized version of the two vectors defined from the points. In this case only 2 vectors are defined.
For the IN_PATCH_JOINT, normals at the corners of the patch used to compute the normal at any point in the patch. In this case tree vectors are defined

Definition at line 155 of file joint.h.

Referenced by CopyJoint(), GenerateJointEquations(), GenerateJointEquationsInBranch(), NewFixJoint(), NewFreeJoint(), NewInPatchJoint(), NewPrismaticJoint(), NewRevoluteJoint(), and NewUniversalJoint().