Performance Criteria - Van Doren and Tesar have formulated and implemented in software over 30 performance criteria. These criteria emphasize task-based performance indicators derived from the physical description of the manipulator. These formulations emphasize efficiency and portability. Available computing power makes decisions based on several of these criteria possible in real-time. Given the rapid pace of advancements in computational speed, it will soon be possible to employ the entire suite of performance criteria in a real-time decision making process. The general categories of these performance criteria are listed below. Continuing work focuses on issues of normalization and multiple criteria fusion.
constraint criteria - physical limitations
geometric - task independent
inertial - from dynamic models
compliance - design and operational issues
kinetic energy - content and distribution
Elementary physical limitations form the basis for the constraint criteria. These limitations restrict joint travels, joint speeds, joint accelerations, and joint torques. The joint travel availability is a representative criterion that seeking to keep the joint displacements as near as possible to the midpoints of their travel.
The Jacobian matrix forms the basis for the geometric performance criteria. These criteria are task independent and based only on the geometry of the robot, thus these criteria are formulated once for each robot with no need for reformulation if the task changes.
The inertial performance criteria have their basis in dynamic models of forces and torques within the robot and are essential to the intelligent design and application of robots. The rate of change of inertial criteria measures how fast the robot can respond to torque and force demands. They are especially important because larger actuators or higher gear ratios can supply more torque, but both will slow the overall response of the robot to external disturbances.