Research on Precision Control Strategy of Electro-hydraulic Proportional System for Shotcrete Robotic Arm Based on PID-MPC

This study addresses the slow dynamic response and significant hysteresis in nonlinear hydraulic systems of shotcreting robots. Using a 6-DOF shotcreting manipulator as the platform, an electro-hydraulic proportional control system was designed, and its mathematical model was established. Operational data were filtered, and system parameters were identified via a least squares-optimized particle swarm algorithm to derive an accurate transfer function. A dual-loop control strategy integrating PID closed-loop control (inner loop) and model predictive control (MPC, outer loop) was proposed for system optimization and simulation. Results indicate that the PID-MPC algorithm reduced the simulation settling time to 0.2 s and stabilization time to 0.5 s, significantly enhancing response speed without overshoot. Experimental validation confirmed significant reductions in speed tracking error and maximum settling time, directly evidencing enhanced control performance This methodology provides theoretical and experimental foundations for automated intelligent shotcreting technology.