Card 9 - JOINT Definition

KODE

KODE is the code JOINT (or 50)

N1

N1 is the joint number.

T1

T1 is the joint type. It can be REVOLUTE for a rotational joint or TRANSLATIONAL for a translational joint.

T2

T2 is a parent joint number. The parent joint number is zero when the joint is a primary joint.

T3

T3 is a vector number. For a rotational joint, the elements rotate about the given vector. For a translational joint, the elements move along the given vector. For more information, see Card 9 - VECTOR.

Code example

ARTICUT 1 ARTICG1 5.
JOINT   1 REVOLUTE 0 1
VECTOR  1 0. 0. 0. 0. 0. 1.
$
$ ELEMENTS IN GROUP ARTICG1 ROTATE AT A SPEED OF 5 DEGREES PER SECOND ABOUT
$ VECTOR 1.
$
ARTICUT 2 ARTICG2 10.
JOINT   2 REVOLUTE 1 2
VECTOR  2 1. 0. 0. 0. 0. 1.
$
$ ELEMENTS IN GROUP ARTICG2 ROTATE AT A SPEED OF 10 DEGREES PER SECOND ABOUT
$ VECTOR 2 RELATIVE TO ELEMENTS OF GROUP ARTICG1. THE ABSOLUTE MOVEMENT OF JOINT 2
$ IS THE MOVEMENT OF JOINT 2 RELATIVE TO JOINT 1 PLUS THE MOVEMENT OF JOINT 1.

Notes

The movement of an articulating member is defined by both ARTICUT and JOINT Cards. An articulation may consist of multiple joints. These joints form a chain.

An example of such a joint chain is a robotic arm. The multi-joint articulation is handled by assigning a parent to a joint to represent the relative movement. A parent of a joint can have its own parent. Only the first joint in a chain has no parent.

The joint definition is used with an articulation definition card 9 ARTICUT. The joint number of the joint definition card is associated with the same joint number of the articulation definition card.