Isotropic velocity radius (IVR) and isotropic acceleration
radius (IVR) are proposed as local performance indices to quantify the
dynamic responsiveness of a multi-arm robot as regards the velocity effects.
These performance measures are defined on the basis of the acceleration set
describing the effects of actuator torques, velocity of the manipulated object,
and gravity upon the acceleration of the object. An algorithm is presented to
obtain an explicit expression for calculating these measures by decomposing the
torque-related non-square matrix into square matrices without using the concept
of pseudo-inverse for the planar multi-arm robot composed of arms each with two
joints.
Numerical examples for a planar robot with two 2R arms show that
the proposed concepts are effective in representing the acceleration capability
and velocity effects of a multi-arm robot.