Optimization of Energy Consumption of Industrial Robots Using Classical PID and MPC Controllers

Abstract

Industrial robots have a key role in the concept of Industry 4.0. On the one hand, these systems improve quality and productivity, but on the other hand, they require a huge amount of energy. Energy saving solutions have to be developed and applied to provide sustainable production. The purpose of this research is to develop the optimal control strategy for industrial robots in order to minimize energy consumption. Therefore, a case study was conducted for the development of two control strategies to be applied to the RV-2AJ Mitsubishi robot arm with 5 DOF, where the system is a nonlinear one. The first examined controller is the classical linear proportional integral derivative (PID) controller, while the second one is the linear model predictive control (MPC) controller. In our study, the performances of both the classical PID model and the linear MPC controller were compared. As a result, it was found that the MPC controller in the execution of the three defined reference trajectories [(1) curve motion, (2) N-shaped motion, and (3) circle motion] was always faster and required less energy consumption, whereas in terms of precision the PID succeeded in executing the trajectory more precisely than the MPC but with higher energy consumption. The main contribution of the research is that the performances of the two control strategies with regard to a complex dynamic system were compared in the case of the execution of three different trajectories. The evaluations show that the MPC controller is, on the one hand, more energy efficient; on the other hand, it provides a shorter cycle time compared to the PID controller.

Selected Issues, Methods, and Trends in the Energy Consumption of Industrial Robots

“…• Trajectory optimization; • Operation planning. Article [44] describes a study that aimed to develop an optimal control strateg dustrial robots to minimize energy consumption. The study includes a case study two controllers were developed for use in the Mitsubishi RV-2AJ robot arm.…”

“…Th estimated the energy efficiency of the robot during pick-and-place operations alo ear path. To achieve this, the study implemented electromechanical and dynamic Article [44] describes a study that aimed to develop an optimal control strategy for industrial robots to minimize energy consumption. The study includes a case study in which two controllers were developed for use in the Mitsubishi RV-2AJ robot arm.…”

The Five-DOF Explosion-Removal Manipulator Based on Position and Velocity Feedforward Compensation Control

“…When the deviation is eliminated, the output stops changing; K D is used to improve the steady-state performance of the system. The larger the K D adjust, the better the system can respond in advance, but it will also amplify unnecessary deviations [28,29]. The PID control parameter tuning method tuning steps are first proportional, then integral, then differential.…”

“…Sensors 2023, 23, x FOR PEER REVIEW 17 of 24 respond in advance, but it will also amplify unnecessary deviations [28,29]. The PID control parameter tuning method tuning steps are first proportional, then integral, then differential.…”

Regression Model for the Prediction of Total Motor Power Used by an Industrial Robot Manipulator during Operation

“…Precise modeling of robot power can be key when discussing robot dynamics as it's directly related to torque [1], energy use of robots [2], or for general control of robotic manipulators [3,4]. Motor power is a possible input to different models-such as fault detection based on machine-learning type observers [5], path control and correction [6], energy consumption optimization [7], and general performance monitoring [8].…”