Force/position-based velocity control strategy for the lower limb rehabilitation robot during active training: design...

Area of Science:

• Robotics
• Rehabilitation Engineering
• Biomechanics

Background:

• Existing lower limb rehabilitation robot control strategies often struggle to balance trajectory tracking accuracy with patient engagement.
• Ensuring both precise movement and active patient involvement is crucial for effective lower limb rehabilitation.

Purpose of the Study:

• To propose and validate a novel force/position-based velocity control (FPVC) strategy for a hybrid end-effector lower limb rehabilitation robot (HE-LRR).
• To enhance trajectory tracking performance and facilitate adjustable active patient participation during robot-assisted training.

Main Methods:

• Detailed description of the HE-LRR configuration and inverse Jacobian analysis.
• Design and implementation of the FPVC strategy, including normal and tangential velocity planning.
• Experimental validation using trajectory measurement, force/velocity measurement, and active participation experiments.

Main Results:

• The FPVC strategy demonstrated excellent end-effector following performance along the reference trajectory and to the desired velocity.
• Experimental results confirmed that patient active participation levels can be effectively modulated by adjusting control strategy parameters.
• The HE-LRR system, utilizing the FPVC strategy, met the requirements for both trajectory tracking and active participation.

Conclusions:

• The proposed FPVC strategy is rational and effective for lower limb rehabilitation robots.
• This control approach shows significant promise for improving robot-assisted active training for patients.
• The FPVC strategy offers a viable solution for enhancing the efficacy of lower limb rehabilitation robotics.