外文翻译--新型直动式压电电液伺服阀复合控制方法(编辑修改稿)

外文翻译--新型直动式压电电液伺服阀复合控制方法(编辑修改稿)内容摘要：

control loop， a high— precise fuzzy control algorithm was adopted． The method can obtain good performance． 3． 2 High precise fuzzy control Conventional fuzzy controller has two input variables， e and Δ e， and one output variable （ U） ， they are error, change of error and output control of fuzzy controller． In the new type of piezoelectric electrohydraulic servo valve system， the physical range of the slide valve position error( and change of error (△ e) are [x， x] and [Δ x ， Δ x]， respectively． The corresponding discrete universes of discourse of e， △ e and u are E， EC and U respectively． E, EC and U are designed as normalized form ： {n， (n一 1)， ⋯， 0， ⋯， n一 1， n}(i=1， 2， 3) (3) 第 页 4 The scale factors are ek，eck and uk， respectively. Then xnke /1, xnkec /2,3/nyku  (4) Based on control rule of conventional fuzzy controller, when eke 0． 5 and ekec 0． 5， the conventional fuzzy controller considers the inputs e and e as zero and the output u is also zero． However, the inputs e and △ e are not certainly equal to zero. Hence conventional fuzzy controller has control dead zone. Control dead zone of conventional fuzzy controller is the main reason why the steady state precision of lookup table algorithm is poor. The key to improving the controlling precision of fuzzy control algorithm based on lookup table is to eliminate its control dead zone. To resolve this problem, an improved fuzzy controller is adopted. When E or EC is not equal to 0, the lookup table is adapted to calculating the control output U。 when E or EC are equal to 0, Interpolation algorithm is adopted to calculating the control output U’ instead of quantization. The method of interpolation calculation is shown in . The U(I,j),U(i+1,j),and U(i+1,j+1) are four point in the lookup table ,and the value of U’ can be calculated based on them. 4. Experimental research The position precision of the new type of piezoelectric electrohydraulic servo valve system is significantly reduced due to the effect of nonlinearity and uncertainty． In this paper，the highprecise fuzzy control method with Preisach hysteresis nonlinear model in feedforward loop was developed to solve this problem. To demonstrate the effectiveness of this proposed control method ， a series of experiments were performed on the new type of piezoelectric electrohydraulic servo valve system under various conditions． The experimental setup was built. which consisted of industrial control puter, hydraulic pressure experimental bench ， pumping station ， PES arbitrary waveform generator(Model AG1200， Yokogawa Co． ) and multipurpose FFT analyzer (Model CF5220， Onosokki Co． )． The experiments were conducted under a hydraulic pressure of 7 MPa. Hydraulic pressure experimental bench was used to provide the operational environment for the PESV . Pumping station was used to provide the liquid pressure for hydraulic pressure experimental bench． Waveform generator was used to provide the waveform． Fourier analyzer was used to analyze the experimental result． Industrial control puter was used to receive the position feedback signals and provide control voltage based on the proposed control method． The industrial control puter still includes a 12 bit AD／ DA card (Model PC一 63 l1， Zhongtai Co． )， a power amplifier and program of the proposed control method． Industrial control puter accepts the given signal from waveform generator and position feedback signal through A／ D conversion interface， soon afterwards， calculates the control voltage signal based on the proposed the control method and sends it through D／ A conversion interface to a power amplifier． In the power amplifier, the control method was amplified with l 0 times gains to drive the piezoelectric actuator of the PESV The position feedback signal was also sent to the Fourier analyser for analyzing the experimental data besides sending to industrial control puter for calculating the control voltage． Firstly, the experiments were done under open loop control， PID control， and high— precise fuzzy control method with Preisach hysteresis nonlinear model in feedforward 第 页 5 loop． The hysteresis loop curves were plotted． Fig． 6(a) shows the hysteresis loop output curve of the system under open loop contro1． It was calculated that hysteresis loop is about 13． 08％ and the maximum output hysteresis is about m． Fig． 6(b) shows the hysteresis loop output curve of the system under PID control method． It was calculated that the hysteresis loop is about ％ and the maximum output hysteresis is about m． This control method can restrain the nonlinear effects of the system． Fig． 6(c) shows the hysteresis loop output curve of the system under the highprecise fuzzy control method with Preisach hysteresis nonlinear model in f。