Design of a Wankel pump constant pressure grouting system based on Fuzzy PID Method

Abstract

Abstract In underground engineering disaster management, existing grouting devices are mainly plunger pumps with large output pulses, which easily cause secondary damage to the surrounding rock of tunnels. Using a rotary piston Wankel pump, an intelligent dual-liquid grouting automation control system (SDUZJ) was developed based on the Fuzzy-PID composite control method to achieve steady output pressure control. Fuzzy control was used when the target and current pressure difference was large to improve self-adaptability and response time. Conversely, PID controller was used when the difference was small to eliminate static differences for steady-state regulation. Combined with the human–computer interaction interface of the computer, automatic control of dual-liquid grouting, alarm recording, real-time monitoring curve, system data setting, and historical data query were realized. A constant-pressure fracturing grouting model experiment with three-axis stress was performed using the proposed system. The Fuzzy control mode was selected to rapidly increase the grouting pressure and flow (pressurization stage) and adjust the grouting pressure to the target value (fracture initiation stage) through rapid rotation of the stepper motor. In the pressure stabilization and fracturing expansion stage, the PID control mode was used for grouting pressure and flow stabilization. Therefore, the Fuzzy-PID pressure stabilization grouting control was realized.