气动侧摆关节的动态特性

针对目前气动关节存在的缺点,提出了采用气动柔性驱动器(flexible pneumatic actuator,FPA)直接驱动,模拟人手指侧摆运动的侧摆关节。介绍了侧摆关节的工作原理。根据热力学第一定律,结合关节的动力学方程,推导建立了关节的转角及输出力矩的动态模型,并进行了仿真分析研究了关节的动态特性;试验研究了侧摆关节的动态特性,分析了关节转角及输出力矩的实际动态响应较慢原因;采用了串联双闭环控制方法,对关节的转角及输出力矩进行了控制研究,结果表明:期望角度为15°时,关节转角闭环动态响应时间约为0.3s,稳态相对偏差小于0.65%;期望输出力矩为188N?mm时,闭环输出力矩动态响应约为0.3s,稳态相对偏差小于1.5%。侧摆关节可控性高,可满足多指灵巧手关节设计要求。

Dynamic characteristics of pneumatic side-sway joint

Because of shortcomings of the existing pneumatic joints,side-sway joint driven by FPAs directly was proposed which could simulate swing movement of human hand.The operating principle of the side-sway joint finger was presented.According to the first law of thermodynamics,combined with dynamic equation of the joint,the dynamic model of the side-sway joint was established.Experiments were carried out to test the static and dynamic characteristics of the joint.There was certain error between experimental curve and theoretical curve,and the error cause was analyzed.Using a series dual loop control method,the output angle and output force of joint were controlled.The results showed:when expected output angle was15°,the loop dynamic response time was about 0.3 s,and the steady-state relative deviation was less than 0.65%.When expected output force was 188 N·mm,the loop dynamic response time was about 0.3 s,and the steady-state relative deviation was less than 1.5%.The side-sway joint can meet the requirement for designing multi-fingered dexterous hand joint.