Tham khảo tài liệu 'advances in robot navigation part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Gait Training using Pneumatically Actuated Robot System 229 The overall exoskeleton structure is positioned on a treadmill and supported at the pelvis level with a space guide mechanism that allows vertical and horizontal movements. The space guide mechanism also prevents a backward movement caused by the moving treadmill belt. Space guide mechanism is connected with the chassis equipped with a weight balance system which ensure balance during walking. The developed system is capable to support person heavy less than 85kg. Fig. 5. Realized prototype of the overall rehabilitation system 4. Kinematical behaviour and joint forces In order to develop the control system it is useful to analyze the actuator forces necessary to move the mechanical system with reference to the shinbone and thighbone angular positions. Since the system is a rehabilitation one with slow velocities dynamic loads will be neglected in the following. The articulations have only one DOF or they are actuated by only one pneumatic actuator . The kinematic scheme of the leg is shown on the . P H B 1 PHA 81 AHB Y1 BHK 01 ABH 2 HKC 82 CKD Y 2 DKO 02 CDK Fig. 6. a Kinematic articulation scheme and b free body diagram of the leg 230 Advances in Robot Navigation The P1 segment represents the pneumatic actuator of the thighbone the p2 segment represents the pneumatic actuator of the shinbone whereas the hip angle position is indicated by the Bl angle with reference to the vertical direction and the knee angle position is indicated by the B2 angle with reference to the thighbone direction. By means of simple geometric relations the process that calculates the length of the actuator of the shinbone once known the rotation angle B2 is described with 1 . The equations 1 show this process for the shinbone considering the geometrical structure and the connections between different components. ỗ2 n 02 Y2 a2 p2 y c2 d2 2cd cos S2 1 After the calculation of the actuators length p2 the angle p2 can
