A New Method to Reduce Energy in Trajectory Planning

Abstract

A new method to reduce energy in trajectory planning will be proposed in this paper, and it is found that it can significantly reduce the energy. The method is to smooth the planned trajectory with a well-designed low-pass filter. The low-pass filter has the ability to block high frequencies and pass the low frequencies, so it can smooth waveforms and form a chamfer-like effect at the mutation. Besides this advantages, it is found that after using a low-pass filter to handle the Cartesian trajectory, the sampling points will be denser at the beginning and end of the Cartesian space trajectory than the original trace. This change can ensure the joint angle velocity smoothly change from zero to zero, which means the trajectory will be run in a smooth state without step or shake. Using the dynamics can calculate the joint torque, then multiply the joint torque with the joint angle velocity to get the joint power. And at last, the energy consumption of every joint can be gotten by integrating the joint power. As it is concluded from the simulation result, smooth the trajectory with a well-designed low-pass filter can protect the motor and reducer and extend the life of the manipulators, and every joint energy consumption can be greatly reduced. And the reduction of energy consumption is related to the shape of the original trajectory and the cut-off frequency of the low-pass filter.