Study On Electro-hydraulic Proportional Servo System Of Hydraulic Hoister

Hydraulic hoister is widely used in lifting and droppin personnel and materiel as a important equipment of mine, which is a typical hydraulic system with large inertia, time-varying parameters and time delay non-linear properties. The existing hydraulic hoister control system seriously affects the efficiency of mine hoisting system and production safety, due to its manual open-loop control which result in low control level, poor precision and lack of cooperation between the driving and braking system. The electro-hydraulic proportional servo technology is applied in hydraulic hoister to improve the control level, so the electro-hydraulic proportional servo system for hydraulic hoister is established, the close loop automatic speed control system and working cooperation between the driving system and braking system of hydraulic hoister is achieved.Based on the dynamic machematic model of A4VSO electro-hydraulic proportional servo variable displacement pump, the performance of pump and the influence of oblique plate reacting force to variable displacement mechanism is analyzed through simulation. The optimized PI parameters were gained by adopting PI adjustment aimed for generalized error square integral optimization, the dynamic and steady performances of adjusted variable displacement pump were tested. The mathematical model of electro-hydraulic proportional servo speed control system was established and the study on PID optimizing control and fuzzy PID smith pre-estimated optimizing control were promoted aimed at the properties of time delay, varying parameters and large inertia load. Through the analysis and comparison of the stability and adaptability with variational inertia load under different control policy, the result indicated that fuzzy PID smith pre-estimated optimizing control can satisfy the control performances of hydraulic hoister.The main facts that influenced response time of braking system is gained through the dynamic performances analysis of existing hydraulic hoister braking system, and the basal reason of lack of cooperation between the driving system and braking system is widely variable load were indicated. The fuzzy auto-cooperating braking system of hydraulic hoister is established through the application of electro-hydraulic proportional control technic and fuzzy control policy. The experimental platform of hydraulic hoister electro-hydraulic proportional servo system was built up, and the relational experiment is done to realize above control policies and validate analysis results.This dissertation analyzed the performance of hydraulic hoister electro-hydraulic proportional servo system through the establishment of the model, the research of control policy, the verification of the test results, it has theoretical significance and practical value to the design and reconstruction of hydraulic hoister.