Time-optimal control of robotic manipulators with limit heat characteristics of the actuator

In this paper, we present a time-optimal control scheme for a robot manipulator to track a predefined geometric path, subject to constraints due to the limit heat characteristics of the actuator (the DC motor was assumed to be the actuator used). Constraints due to the rated torque bounds and the rated velocity bounds of the motor would not be valid for continuous use of the manipulator, since the required mechanical output of the actuator (DC motor) exceeds its maximum power capacity and greatly exceeds its heat-converted power limit. The heat-converted power of the DC motor is thus considered as the actuation bound and the time-optimal trajectories are generated subject to this bound. Computer simulation was also executed to demonstrate the effectiveness of the proposed scheme in comparison to former schemes that used the rated torque and the rated velocity.