主被动踝关节假肢力/位混合控制研究

为了满足小腿截肢患者的运动需求，根据踝关节在人体步态周期中的生物力学特性，结合已有的研究基础和实验条件，研制了第一代主被动混合驱动的踝关节假肢样机。通过对样机仿生运动的分析和运动模型的建立，提出了一种基于有限状态机的力/位混合伺服控制系统，采用PID和模糊PID两种控制算法对假肢运动进行Matlab仿真和角度控制实验。实验结果表明，该假肢样机可以得到类似人体运动的踝关节角度-力矩曲线，并且模糊PID算法控制输出的曲线更加符合人体特性，从而验证了样机设计的合理性和控制方案的可行性，为进一步实现样机的应用提供了依据。

Hybrid Force/Position Control Research of Hybrid Active-Pqssive Powered Ankle-Foot Prosthesis

With the development of intelligent control algorithm and electronic technology, it becomes an important research direction in domestic and international studies to develop the dynamic ankle-foot prosthesis for the lower leg amputees. In order to achieve this goal, we designed a kind of hybrid model of ankle joint prosthesis which was emulated by Adams and got humanoid ankle angle and angle velocity curves in human walking. This paper designed the first generation of hybrid powered ankle-foot prosthetic prototype, combining active and passive actuators is designed which is combined with the existing research base and experimental conditions and based on the biomechanics characteristics of ankle in the human gait cycle to meet the demand of the movement of the shank amputees. The mechanical structure of prosthesis includes series elastic actuator, parallel spring mechanism, synchronous belt, lead screw drive system and direct current servo motor. Through analysis of the bionic movement of prototype and the build of prototype kinematic model, this paper proposes a servo system with hybrid angle/torque control based on the finite state machine. The kinematics analysis of prosthesis is carried out to meet the functions of ankle in working. And finite state machine control algorithm is used in different stages in gait cycle by different control methods. It uses matrix laboratory simulation of the prosthetic movement and the angle control experiment with the PID and fuzzy PID control algorithms. The result shows that the movement of ankle joint prosthesis can be similar to the ankle angles-moment curve of the human body, and the curve of fuzzy PID control algorithm''s output is closer to the human body characteristics, which verifies the rationality of the design and the feasibility of control scheme. The research can provide foundation for the application of prototype.