Design of a center-driven upper limb rehabilitation robot and its trajectory planning
10.3760/cma.j.cn121382-20250708-00052
- VernacularTitle:中央驱动式上肢康复机器人的设计与轨迹规划
- Author:
Shunpeng XU
1
;
Hongliu YU
;
Yang BO
Author Information
1. 上海理工大学智能康复工程研究院 民政部神经功能信息与康复工程重点实验室 上海康复器械工程技术研究中心，上海 200093
- Keywords:
Robot;
Center-driven upper limb rehabilitation robot;
Object retrieval;
Quadrilateral drawing;
Trajectory planning
- From:
International Journal of Biomedical Engineering
2025;48(5):435-442
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To design a center-driven upper limb rehabilitation robot, and to perform trajectory planning and simulation based experimental validation for two rehabilitation tasks: object retrieval and quadrilateral drawing.Methods:Firstly, the mechanical structure and system of the center-driven upper limb rehabilitation robot were designed. The mechanical structure included a micro-power system installed at the end of the robotic arm, enabling four-degree-of-freedom motion through a multi-stage transmission system. The system was mainly divided into two parts: the control system and the power system. Then, a kinematic model was established using the D-H method, and the safe workspace of the robot was analyzed. Finally, the quintic polynomial interpolation method was adopted to plan the motion trajectories for two typical rehabilitation actions, namely object retrieval and quadrilateral drawing, and it was validated through Matlab simulation experiments.Results:The object retrieval action of the center-driven upper limb rehabilitation robot was divided into six stages. In Stage 1, the end handle of the robotic arm was moved from the origin to the initial position within 3 s, with only shoulder flexion/extension angle ( θ1) rotated by ?60°. Stage 2 was defined as a motion interval lasting 2 s, during which all joints remained stationary. In Stage 3, the end handle was moved from the initial position to the end position within 5 s, with θ1 rotated by 30°, shoulder adduction/abduction angle ( θ2) by 15°, and elbow flexion/extension angle ( θ3) by 60°. Stage 4 was a rest interval of 3 s, with all joints kept stationary. In Stage 5, the end handle was returned to the initial position within 5 s, with θ1 rotated by ?30°, θ2 by ?15°, and θ3 by ?60°. Stage 6 was a final rest interval of 2 s, with all joints stationary. The quadrilateral drawing motion of the center-driven upper limb rehabilitation robot was also divided into six stages. In Stage 1, the end handle was moved from the origin to vertex 1 of the quadrilateral in 5 s; θ1 remained unchanged, θ2 was rotated by 30°, and θ3 by 60°. Stage 2 was defined as a motion interval lasting 2 s, during which all joints remained stationary. In Stage 3, the end handle was moved from vertex 1 to vertex 2 in 3 s, with θ1 rotated by 30°, θ2 by ?60°, and θ3 by ?60°. In Stage 4, the end handle was moved from vertex 2 to vertex 3 in 4 s, with θ1 rotated by ?60°, θ2 by 30°, and θ3 unchanged. In Stage 5, the end handle was moved from vertex 3 to vertex 4 in 4 s, with θ1 rotated by ?30°, θ2 by 15°, and θ3 by 60°. In Stage 6, the end handle was moved from vertex 4 back to vertex 1 in 2 s, with θ1 rotated by 60°, θ2 by 15°, and θ3 unchanged. Simulation results showed that the shoulder, elbow, and wrist joint angles all varied smoothly along the quintic polynomial trajectories, and the end-effector accurately tracked the predefined paths for both object retrieval and quadrilateral drawing. Conclusions:A center-driven upper limb rehabilitation robot was designed, which can realize the trajectory planning of two rehabilitation actions, namely object retrieval and quadrilateral drawing.
