Placement of a Manipulator for Minimum Cycle Time

Productivity of a manipulator depends, largely, on the time it takes to traverse a path, which is a function of the capacity of the actuators to produce torque. Increasing the torque capacity of the actuators to reduce path traversal time may be unrealistic in many cases. Therefore, this article studies the effects of the manipulator location, within a workcell, on the path traversal time. The article defines the boundaries of the manipulator base locus when the end-effector path is prescribed. Effects of joint mechanical limits and obstacles on this locus are also considered. The proposed algorithm uses nonlinear programming to search the manipulator base locus for the base location that yields the minimum time to traverse a path, subject to the actuator torque constraints of the manipulator. Detailed examples are included