Research On Design And Performance Of Flexible Pneumatic Actuator

Software robots focus on the use of soft,flexible materials rather than rigid joints like traditional rigid robots.Therefore,software robotic actuators can also be called artificial muscles because they have similar characteristics to biological muscles.In order to reflect the superior performance of the software robot,the design of the driver is very important.Although many types of pneumatic flexible actuators have been proposed in previous studies,the development of pneumatic flexible actuators with large strain and low driving pressure is still a challenge.In this thesis,a simple pneumatic flexible actuator structure is proposed,which can produce large deformation,movement and force under low driving pressure.It also solves the problem of large elongation of flexible actuator.Based on the new pneumatic flexible actuator,this thesis also proposes a flexible bending joint structure that produces a large angle of bending at low driving air pressure.Firstly,the structural principle of the new pneumatic flexible actuator is proposed,and it presents a kind of expandable corrugated pneumatic actuator.The motion mechanism of the actuator is explained,and the manufacturing process of the new pneumatic flexible actuator is also elaborated.The basic characteristics of the actuator are studied,and the static theoretical model is analyzed.The theoretical characteristics of the actuator under constant load,constant voltage and constant length are analyzed in combination with MATLAB.Sencondly,based on the new pneumatically flexible drive,three identical actuators were used to form a flexible curved joint with a 120° uniform assembly.In the third chapter,the structure and motion mechanism of the bending joint are expounded in detail.According to the geometric principle,the kinematics model is established,and the theoretical bending angle of the bending joint under different air pressure is analyzed.The pneumatic experimental platform was built to test the performance of the pneumatic flexible actuator,including constant load,constant pressure and constant length performance tests.At the same time,the theoretical values were compared and verified to verify the correctness of the theoretical model.Secondly,the experimental study of the bending joint was carried out,mainly by maintaining the same air pressure in the inner cavity of the two actuators,and the bending motion of the flexible bending joint was achieved by increasing the pressure of the third actuator inner cavity,which was measured by photographing with an industrial camera.The bending angle during the movement is compared with the theoretical value,and the correctness of the bending model is analyzed.The experimental results show that the pneumatic flexible actuator can achieve a large strain of more than 200% under the air pressure of 0.3 MPa,and the bending joint can reach a large bending angle of more than 180° under the pressure of 0.2 Mpa.The new pneumatic flexible actuator and flexible driving joint designed in this paper have the characteristics of small driving pressure and large deformation.The research results can provide a solid structural foundation for the subsequent development of bionic flexible manipulator.