Research On Quick-wear Upper Limb Assist Device Based On Pneumatic Muscle Driv

The fast-wearing exoskeleton on upper limb is a device which can provide handling assistance and enhance upper limb functions.Its development and research is based on the integration of human anatomy,mechanical engineering,electronic control technology and other disciplines.It is a typical mechatronics device.It has important research value and wide application prospect in military and industrial neighborhood.The design principle of upper limb booster exoskeleton is based on human-machine combination.Pneumatic muscle is a new type of pneumatic actuating element.Compared with conventional actuators,it has advantages of good compliance,high power-mass ratio,safety and reliability.In this paper,it is used as the driving mechanism of upper limb booster and relevant research on upper limb booster system is carried out.Firstly,combined with kinematics foundation of upper limb joint,the overall mechanical structure of relevant upper limb booster device is designed so that the degree of freedom can meet the requirements of free movement of upper limb.Aiming at the problem that lumbar joint assist is not considered by most upper extremity exoskeletons at present,this paper designs a structure which can realize the user’s lumbar assist.At the same time,the overall structure layout is optimized by combining active assist with passive assist of ratchet pawl using pneumatic muscle as actuating element.Secondly,kinematics and dynamics of arm structure of upper limb are studied.Spatial motion equation is established by D-H method and space motion cloud diagram is solved by using the mathematics software,which verifies the feasibility of structure design by using the dynamic simulation software simulation,the law of torque variation of lumbar-shoulderelbow joint during movement is analyzed,which provides reference for selection of pneumatic muscle.Furthermore,for the control of upper limb assist system,a control strategy which uses voice control to identify the intention of human motion and uses joint rotation as a given reference trajectory tracking control is proposed.Taking single joint rotating mechanism as controlled object,an improved PID control method based on fuzzy principle is designed.After deriving the mathematical model of each subsystem,the control simulation model is established by using the system simulation software,and the control effects of the fuzzy PID and the common PID are compared,which verifies the correctness of the system model and the improvement effect of the fuzzy PID control.Finally,the physical prototype and test platform are built,the fuzzy PID controller is developed,and the experimental test is completed,which verifies the correctness of the structural design and the feasibility of the control strategy.The designed booster equipment can meet the wearing requirements and adapt to the changes of external loads.It can achieve certain boosting effect under the control of man-machine cooperation.It can assist the wearer to carry heavy objects and enhance the upper limb function.