3自由度气动柔性手指包络抓持力模型研究

Static Model of Envelop Grasping for 3-DOF Flexible Pneumatic Finger

提出了一种基于气动柔性驱动器的3个自由度手指指节法向力可控的包络抓持模型。分析了目标物体受力状况,按照手指指节与目标物体之间的各个接触力尽量均匀的原则,对目标物体受力进行了优化。建立了关于手指指节接触点所受到的法向力及摩擦力与关节驱动器输出力之间的力学模型。使用2个触力传感器,应用杠杆原理建立了接触点法向力及其作用点的测量模型。提出了指节接触点法向力的双闭环控制策略,设置了补偿器对摩擦力进行实时补偿,对压力反馈信号进行微分处理,用以消除压力检测信号中所包含的高频噪声。搭建了试验平台,试验结果表明:手指法向力动态响应时间为约1 s,误差范围稳定在±0.5 N。

Envelop grasping model based on 3-DOF fingers driven by a flexible pneumatic actuatordirectly was proposed. Based on the principle of equalization, the interaction forces between the object and knuckle was optimized. The static model of the pressured air in FPAs and the positive pressure on knuckle or correlative friction force was built. The measure model about the positive pressure and its position, based on leverage principle depending on two touch-force sensors, was obtained. Using a series dual loops control method and the compensator about friction force, the positive pressure could be controlled precisely. In order to filtrate the high-frequency noise, the feedback signal of the pressured air in FPA was processed by different analysis. The experimental results showed that dynamic response time of the positive pressure was about ls and the steady-state deviation was less than ± 0.5 N.