A new type of ankle prosthesis with lower power combining active and passive actuators is designed based on the research results of human ankle joint biomechanics. The human motion during level walking with slow speed is divided into four phases by analyzing the relation of ankle joint torque versus angle, the idealization and decomposition of walking movement, which are the plantarflexion after heel-strike buffering, the dorsiflexion during body forward, the plantarflexion during pushing off ground and swing. A series elastic actuator system and a parallel spring are used to produce walking motion, and the ankle prosthesis is designed with a series elastic actuator and parallel spring. The motion simulation of ankle prosthesis is implemented with SolidWorks and ADAMS softwares. The results show that the ankle prosthesis can realize the expected movement trajectory, which verifies the correctness of the design.
 Hwang S, Kim J, Yi J, et al. Development of an active ankle foot orthosis for the prevention of foot drop and toe drag [C]//International Conference on Biomedical and Pharmaceutical Engineering. Piscataway, NJ, USA: IEEE, 2006: 418-423. Kobayashi T, Leung A K L, Akazawa Y, et al. Design of a stiffness adjustable ankle foot orthosis and its effect on ankle joint kinematics in patients with stroke[J]. Gait & Posture, 2011, 33(4): 721-723.  Naito H, Akazawa Y, Tagaya K, et al. An ankle-foot orthosis with a variable-resistance ankle joint using a magnetorheological-fluid rotary damper[J]. Journal of Biomechanical Science and Engineering, 2009, 4(2): 182-191.  Au S K, Herr H, Weber J, et al. Powered ankle-foot prosthesis for the improvement of amputee ambulation[C]//Annual International Conference of the IEEE Engineering in Medicine and Biology. Piscataway, NJ, USA: IEEE, 2007: 3020-3026. Au S K, Berniker M, Herr H. Powered ankle-foot prosthesis to assist level-ground and stair-descent gaits[J]. Neural Networks, 2008, 21(4): 654-666.  Segal A D, Zelik K E, Collins S H, et al. The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation[J]. Human Movement Science, 2011, 31(4): 918-931. Cain S M, Gordon K E, Ferris D P. Locomotor adaptation to a powered ankle-foot orthosis depends on control method[J]. Journal of NeuroEngineering and Rehabilitation, 2007, 4: doi. 10.1186/1743-0003-4-48. 王人成,金德闻.仿生智能假肢的研究与进展[J].中国医疗器械信息,2009,15(1):3-5. Wang R C, Jin D W. Research and development of bionic and intelligent limb prosthesis[J]. China Medical Devices Information, 2009, 15(1): 3-5. 高成,王斌锐,谢华龙,等.异构双腿机器人仿生腿的设计与控制实现[J].东北大学学报:自然科学版,2004,25(11):1030-1033. Gao C, Wang B R , Xie H L, et al. Design and control of bionic limb of biped robot with heterogeneous legs[J]. Journal of Northeastern University: Natural Science, 2004, 25(11): 1030-1033. 谭冠政,赵洪涛.步态相位识别技术在人工腿设计中的应用研究[J].计算机测量与控制,2007,15(10):1315-1318. Tan G Z, Zhao H T. Gait phase identification and its application research on design of artificial leg[J]. Computer Measurement & Control, 2007, 15(10): 1315-1318. 陈静,刘洋,邱长青,等.主动式踝关节假肢运动轨迹的迭代学习控制[J].计算机技术与自动化,2008,27(4):69-71. Chen J, Liu Y, Qiu C Q, et al. Iterative learning control of moving trail of a powered angle prosthesis[J]. Computing Technology and Automation, 2008, 27(4): 69-71. 耿艳利,杨鹏,许晓云,等.动力型假肢膝关节设计与仿真研究[J].河北工业大学学报,2011,40(5):1-4. Geng Y L, Yang P, Xu X Y, et al. Design and simulation of active transfemoral prosthesis[J]. Journal of Hebei University of Technology, 2011, 40(5): 1-4. Han Y L, Wang X S. The biomechanical study of lower limb during human walking[J]. Science China: Technological Science, 2011, 54(4): 983-991.  Vaughan C L, Davis B L, O'Connor J C. Dynamics of human gait[M]. 2nd ed. Cape Town, South African: Human Kinetics Publishers, 1999.