The Research On The Coordinated Control Strategy Of Distributed Electric Direct Driven Hydraulic System

Abstract:Hydraulic systems are widely used in every industrial field, while the motorized device is an important part of the hydraulic system, which determine the static and dynamic characteristics of the system to a large extent. For the problem existing in the motorized device of traditional hydraulic system, this paper propose a new distributed electric direct drive hydraulic servo system for the first time. In this paper, the traditional piston pump controlled by a single rotary motor which called centralized control by changing to distributed control which multiple electric devices driving multiple plungers. This paper has discussed multi-channel coordinated control strategies to achieve faster response speed, reduce unnecessary flow of the system, achieve non-throttle control, improve efficiency of the hydraulic system from the overall, reduce energy consumption, improved the dynamic performance of the system.First of all, this paper analyzes the present study situation of the hydraulic servo system at home and abroad. This paper briefly introduces the working principle of the traditional valve control hydraulic servo system and bump control hydraulic servo system and points out existing problems. To solve these problems this paper put forward a new kind of distributed electric direct drive hydraulic servo system.Secondly, this paper introduces how to select the servo motor and hydraulic cylinder, establishes the mathematical model of the AC servo motor、mechanical transmission device and hydraulic cylinder, simulates and analysis the dynamic characteristics of the AC servo motor and distributed electric direct drive hydraulic servo system. In the third chapter, this paper made a detailed analysis about multi-channel synchronous and coordinated control strategies. Good research on synchronous control is the basis of good research on coordinated control. The PID algorithm is used in the channel.Distributed electric direct drive hydraulic servo system experiment platform is built, including the design of electric control cabinet, hardware of experiment system, mechanical structure, etc. This paper introduced the main components of experimental platform, the design of strong and weak electric circuit, the characteristic parameters of the main equipment and CAD drawings of mechanical platform in detailFinally, this paper designed the PC control software and carried out multiple sets of experiment based on the experiment platform has been built. Including single channel servo motor position step response, sinusoidal response, ramp response, square wave response, which measured the dynamic characteristics of the servo motor, including the response speed, low speed characteristic and frequency response of the servo motor, etc. Then this paper carried out the position synchronous experiment of the dual-channel and four-channel, compared and analyzed synchronous performance of them. At last, speed coordinated control experiment of four-channel was carried out. The experiment result shows that the design of distributed electric direct drive hydraulic servo system can work stable Implements the load position and speed control with high control precision and good synchronous performance; Achieve a coordinated control strategy, which proved the feasibility of this innovative solutions, laid a solid foundation for the subsequent experiments.