Ⅰ、Brief introduction to the paper Ⅱ、Authors’ information Ⅲ、Project based on the foundation

Ⅰ、Brief introduction to the paper

Research source、purpose and significance Source: National Natural Science Foundation of China (Grant No. 51575199) Purpose: Achieve relatively consistent dynamic pressure control performance across the scope of work (2–140 kPa) Significance: Meet the demand of dynamic pressure signal generation in the application of the hardware-in-the-loop simulation of aerospace engineering

Research status In the past decades, a great interest has been shown in pneumatic position servo systems. Compared with that of position servo controls, research on the design of pressure controllers at present is quite limited. At present, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. PID controller and fuzzy controller have been widely used in nonlinear system.

Research contents System description and analysis Design of fuzzy PID controller with asymmetric fuzzy compensator Experimental verification

Open-loop system step responses from simulation and experiment System description and analysis The system uses a compressor and a vacuum pump as positive and negative pressure source. Computer gets pressure signal measured by a pressure sensor and outputs command to an EPPCV, which controls airflow rate and process of chamber charging and discharging. The mathematical model of the system is not very accurate. There exists the asymmetry during charging and discharging processes, especially in the range of lower pressure. Principle sketch of PNPPSS Configuration of the exoskeleton arm system Open-loop system step responses from simulation and experiment

Structure of fuzzy PID controller with asymmetric fuzzy compensator Design of fuzzy PID controller with asymmetric fuzzy compensator Because of the difficulty to obtain the accurate mathematic model, PID controller with a fuzzy inference module is proposed Because of the wide range of pressure and serious asymmetry of charging and discharging process, an asymmetric compensator using the current pressure p and output uf of the fuzzy PID controller as inputs is designed Structure of fuzzy PID controller with asymmetric fuzzy compensator

Fuzzy rules for the fuzzy PID controller Fuzzy rules for the asymmetric fuzzy compensator KP/KI/KD E NB NM NS ZE PS PM PB EC BB/ SS/ SM BM/ SM/ MM MM/ SS MM/MM/ BB BM MM/MM MM/MM/MM MM/MM/BM MM/BM BM/MM Uf P ZE SS SM MM BB VB NB BM VS NS PS PB Membership functions for p, uf and λ

Experimental verification Proposed controller has better performance than PID controller, especially in the condition of lower pressure. Sinusoid and square wave tracing experimental results with PID and proposed controller

Comparison experimental results show that the control performance with the proposed controller is better and relatively stable at different setting pressure The asymmetry of charging and discharging rate can be compensated by the fuzzy compensator The phase and amplitude errors tracking sinusoid Experimental results with fuzzy PID and proposed controller Average value p / kPa Phase error θe / (°) Amplitude error Ae / % Proposed controller Fuzzy PID PID 140 6.2 8.6 3.9 2.4 6.7 7.6 20 6.4 17.9 13.7 2.7 10.7 22.8 5 7.9 36.4 28.9 4.6 3.8 32.6 2 8.1 45.8 42.0 4.7 7.4 38.7 The output of asymmetric fuzzy compensator

Ⅱ、Authors’ information

Yang Gang Assistant Professor, HUST，China Research interest: Electro-pneumatic control system; High-pressure pneumatic component and system; Intelligent control. Tel: +86-27-87541769; E-mail: ygxing_73@hust.edu.cn Li Baoren Professor, HUST，China Research interest: Electro-pneumatic control component and system; Hydraulic control system; System synthesis for mechatronic equipment. Du Jingmin Assistant Professor , HUST，China Research interest: Pneumatics Intelligent control Tel: +86-27-87541769 E-mail: hustdjm@hust.edu.cn Fu Xiaoyun Assistant Professor, HUST，China Research interest: Nonlinear control of dynamic systems; Electro-pneumatic control component and system; System synthesis for mechatronic equipment.

Research areas FESTO Pneumatic Center is organized into the following areas: Intelligent hydraulic/ pneumatic components Electro-hydraulic/ pneumatic servo system High-pressure pneumatic technology Mechatronics/ hydraulic/ pneumatic intelligent control Autonomous Control Technology of underwater vehicle Hardware in the loop simulation technology of aircraft

Honor/ awards The First High Education Award for Science and Technology Progress, 2009 The Second National Award for Science and Technology Progress, 2003

Ⅲ 、Project based on the foundation

Project: FADS dynamic simulation test equipment Technical basis: Positive and negative pneumatic pressure servo technology Function: Simulate atmospheric pressure parameter and measure atmospheric pressure parameter