Time-optimal control of kinematically redundant manipulators with limit heat characteristics of actuators

Abstract

In this study, we present a time-optimal control scheme for kinematically redundant manipulators to track a predefined geometric path, subject to the limit heat characteristics of actuators (a DC motor was assumed to be the actuator used). Constraints due to the rated torque and the rated velocity of the motor would not be valid for continuous use of manipulators, since the required mechanical output of the actuator (DC motor) exceeds its maximum power capacity and far more exceeds its heat-converted power limit. The heat-converted power limit of the DC motor is thus considered as the actuation bound of the actuator and the time-optimal trajectories are generated by using the phase-plane analysis and the linear programming technique subject to this bound. Computer simulation was also executed on a three-link planar rotary manipulator to demonstrate the effectiveness of the proposed scheme.

Keywords:

• Kinematically redundant manipulator
• time-optimal control
• limit heat characteristics of a DC motor
• heat-converted power
• phase plane analysis
• linear programming technique.