Swing Cylinder Magnetorheological Brake Technology Research

Pneumatic technology has been widely used in industrial automation area because of its unique advantages. Following the development of science and technology, industrial automation system requires accurate position control. So far, most of the research has been focused on the position control of the linear cylinder, but fewer researches on the position control of the rotary actuator were reported. Based on its solid characteristics and controllable damping force characteristics, magneto-rheological technology has been widely used in many industrial areas, such as braker, damper, shock absorber, etc. This paper is foucs on using the magnetic current converter brake to control pneumatic rotary actuator's position, designing the magnetic current converter brake's structure scheme and theoretical model, also carrying our performance test. On this basis, calculated and test the rotary actuator's position which controlled by magnetic current converter brake.The main work and achievements are as follows:1) To devise the pneumatic rotary actuator structure combines with magneto-rheological technology. Based on the analysis of magneto-rheological device's work mode, our study designed the structure program of magnetic current converter brake which acted on rotary actuator's position control, then designed the effective structure to achieve magnetism isolating and to seal MRP. Processed the prototype of magnetic current converter brake based on the design.2) To design the magnetic current converter brake's mathematical model. Simulated the moment modeling of the magnetic current converter brake and proved the correctness of theoretical design. In addition, the finite element analysis of the magnetic path structure indicated that the magnetic field intensity in work gap is consistent with the theoretical design.3) To carrying out the performance test on magnetic current converter brake prototype. The results showed that with the increasing of the input current can increase the braking torque of magnetic current converter brake, which presented non-linear relationship. Additionally, the rotating speed had little influence on magnetic current converter brake's braking torque at low rotating speed level.4) To applying the magnetic current converter brake to control position of the pneumatic rotary actuator. The results demonstrated that it can be reduced the braking time of the magnetic current converter brake when increasing the input current. Setting up reasonable parameters, which were the initial braking location and input current, it could promote the position accuracy of the pneumatic rotary actuator. Obtained the location error of pneumatic rotary actuator, which was controlled by the magnetic current converter brake, it was less than±0.85°in the angle range of 50°～200°.Theoretical analysis and experimental results suggest that the magnetic current converter brake, which is researched in this paper, has the reasonable structure and great braking performance. Using this magnetic current converter brake can realized the accurate and stable position control of pneumatic rotary actuator.