ABSTRACT
The position and orientation of the end effector of a robot are frequently expressed by the vectors p and (n, o, a) shown in Figure 11.1 The components of these vectors are given in terms of a fixed Cartesian coordinate frame at the base of the robot. The approach vector a is the unit vector in the direction in which the end effector will normally approach an object. The slide vector o lies along the fingertip-to-fingertip line of a two-fingered gripper. The third orientation vector is a normal vector n which completes a right-hand triad of unit vectors. This can be expressed by the vector product relation
n = o x a
