The Design And Research Of The Lower-limb Power-assist Exoskeleton Robot

The power-assist exoskeleton robot is a kind of mechanical device, which can adjust the intention of operator and provide power for assistance. By analyzing acquired information of human motion, it can provide power to enhance walking ability and speed. The robot will be widely used in military, medical rehabilitation and relief for a large number of advantages. This dissertation mainly researched exoskeleton robot from the mechanical structure and motion control. Main research contents are as follows:1. For realizing function of assistance, the robot structure was designed based on the human anatomy of the lower-limb and gait movement theory. The DOF configuration, the driving joints, driven joints, leg-adjustment mechanism and others are designed, which ensure the adaptability, practicability, comfort and safety of the exoskeleton robot.2. The kinematics model of exoskeleton robot was established, and the kinematics analysis was completed by homogeneous coordinate transformation. According to the joint motion angles of human normal walking from database CGA, characteristics of gait was studied, as well as torque and power of each joint. Then the mathematical model of joint angle's variation was established with curve fitting, which lay the foundation for the research and simulation of gait control.3. Using the Lagrange equation to establish the dynamic equations of exoskeleton robot. For ensuring accurate follow-up and meeting the requirement of human-computer interaction, both position control and force control are used to study the control strategy of joint drive. Based on the characteristics of the motion control, fuzzy-PID is applied to realize precise control.4. The controller was modeled and packaged in Simulink and the effectiveness of the control algorithm is verified by simulation. Then, the co-simulation platform of lower limb exoskeleton robot system was established with ADAMS. The correctness of the model and the validity of the control strategy were verified by co-simulation. The results also show that the trajectory tracking system and the exoskeleton robot system scheme can achieve the desired results.