The Research And Design Of Wide Range And High-precision Intelligent Electro-hydraulic Servo Controller

Electro-hydraulic servo control system has a very wide rang of applications in the fieldof industrial control and automation, especially in the high-power and high-precision controlsystem. The development of electro-hydraulic servo control system has become an importantsymbol to measure a country’s level of industrialization.The servo controller is the corecomponents of the electro-hydraulic servo control system.This paper discusses the researchand design of electro-hydraulic servo controller based on position feedback.This article first describes the composition and working principle of theelectro-hydraulic servo control system, and makes a detailed analysis of each module’smathematical model. At the same time, combined with the specific requirements analysis, itdetermine the overall design of the electro-hydraulic servo controller,which divides into theprocessor module,input singial conditioning module,output signal module,expansioncommunication module,display and keys modules,power module and the hardware circuitfault self-diagnosis modules.In the realization of the servo controller,it uses theTI’TMS320F2812as the core processor chip to design peripheral circuits,and to improve theaccuracy of the circuit as much as possible.The maximum rang of the output current scaleextend from－70mA～+70mA to－100mA～+100mA, and make a high-precision andwide rang achievement of the servo controller. In software, for the nonlinear and variabilityof the electro-hydraulic servo control system, this paper uses intelligent controlalgorithm,which combines the PID control and fuzzy control to compose fuzzy PIDcompound control.This compound control has smaller overshoot,faster response speed andhigher steady accuracy.The test results in the laboratory show that the designed servo controller operatesreliably, which gets the real-time and precise control effect, and achieve the expectedperformance.The innovation of this thesis lies in: the servo controller takes full advantage ofthe powerful data processing capability and control functions of TMS320F2812, the richperipheral interfaces, simplify circuits design to achieve a wide rang and high-precision servocontroller. It makes the addition of self-diagnostic circuit and alarm functions in hardwaredesign, and expands the RS232serial communication features for debugging and fault diagnosising easily.It uses CPLD to control LCD and keys circuits, which makes it possibleto achieve a real-time display of the data, to set the relevant paramenters online.The DSP ofTMS320F2812reads keys coding by interrupt mode, achieving real-time response ofkeys.This design approach reduces the overhead of DSP greatly, and is conductive to therealization of real-time control and the arrangements of program.