Development of a modular, multifunctional, unilateral lower-limb rehabilitation exoskeleton system with assist-as-needed control

Abstract

This invention provides a modular, multifunctional unilateral lower limb rehabilitation exoskeleton system with on-demand auxiliary control. It includes: a main body with a control module and assembly elements on both sides, each assembly element equipped with a magnetic assembly sensor; an affected lower limb mechanism comprising a first drive device, a thigh exoskeleton module, a second drive device, and a calf exoskeleton module; and a healthy lower limb mechanism comprising a first support portion and a second support portion, and respectively equipped with a torque angle sensing element and a trajectory measurement module. The control module drives the first and second drive devices according to the measurements from the torque angle sensing element and the trajectory measurement module. Therefore, this invention only requires one affected lower limb mechanism and one healthy lower limb mechanism to accommodate patients with left or right limbs. A quick-release device allows for rapid left-right interchange; after interchange, the healthy and affected lower limb mechanisms are simply rotated 180 degrees and fastened together. Regarding the difference in gait trajectory between the left and right legs, this invention utilizes the magnetic assembly sensor to automatically identify the patient. Wearing the affected and unaffected lower limb exoskeleton on the left or right foot allows for the initiation of trajectory conversion drives and transmission directions corresponding to different directions and angles of the left and right feet. This reduces costs and effectively improves the applicability of the invention to patients. Furthermore, the invention simplifies the design for the unaffected side of hemiplegic patients. By collecting gait information from the patient's active movements on the unaffected side, it enables unilateral rehabilitation using mirror gait drives that match the patient's gait. Assistive support devices can help patients maintain balance, shift their center of gravity, and identify movement triggers, facilitating personalized learning of natural walking patterns and center of gravity shifting on both the unaffected and affected sides, thus increasing the patient's active participation in the training process. Moreover, the invention allows patients to autonomously initiate walking on the unaffected side, autonomously adjust their posture and center of gravity, and autonomously control walking on the affected side. This enables patients to actively control the lower limb exoskeleton through a closed-loop training mode of "central nervous system - peripheral nervous system (motor and sensory) - central nervous system," simultaneously training the central and peripheral nerves to achieve coordinated recovery of motor and cognitive functions, completing non-invasive neuromodulation-based human-machine fusion rehabilitation training.

Claims

1. A modular, multifunctional unilateral lower limb rehabilitation exoskeleton system development and on-demand auxiliary control, comprising: a main body having a control module, and an assembly element on each side of the main body, each assembly element having a quick-release device, and each assembly element having a magnetic assembly sensor connected to the control module; an affected lower limb mechanism having a first main body, the upper end of the first main body having an assembly portion corresponding to one of the assembly elements for corresponding connection to one of the assembly elements, and the lower end of the first main body having a first driving device that drives and pivotally connects to a thigh exoskeleton module, and the lower end of the thigh exoskeleton module having a second driving device that drives and pivotally connects to a calf exoskeleton module, the first driving device and the second driving device being coupled to the control module; and a healthy lower limb mechanism having a second main body, the... The second main body has a connecting portion at its top corresponding to one of the assembly elements, for corresponding connection to one of the assembly elements. The lower end of the second main body is pivotally connected to a first support portion corresponding to the thigh exoskeleton module, and the bottom end of the first support portion is pivotally connected to a second support portion corresponding to the calf exoskeleton module. A torque angle sensing element is respectively provided between the second main body and the first support portion, and between the first support portions. The healthy lower limb mechanism is provided with a trajectory measurement module. The torque angle sensing element and the trajectory measurement module are respectively coupled to the control module. The magnetic assembly sensor senses whether the affected lower limb mechanism and the healthy lower limb mechanism are assembled on the left or right side of the body, and controls the transmission direction of the first drive device and the second drive device according to the position of the left or right side. The control module identifies the measurement values ​​of the torque angle sensing element and the trajectory measurement module according to the position of the left or right side, and drives the first drive device and the second drive device accordingly. The control module constructs a gait trajectory model through DMP (Dynamic Movement Primitive) based on the measurement values ​​of the torque angle sensing element and the trajectory measurement module. The control module drives the first drive device and the second drive device according to the gait trajectory model, so that the movements of the thigh exoskeleton module and the lower leg exoskeleton module are mirrored on the first support part and the second support part. The control module updates the DMP and generates the gait trajectory model accordingly through path integral reinforcement learning (PIR).

2. The modular multifunctional unilateral lower limb rehabilitation exoskeleton system development and on-demand auxiliary control as described in claim 1 further includes a affected side shoe body, which is correspondingly assembled to the affected side lower limb mechanism; and a healthy side shoe body, which is correspondingly located at the lower end of the healthy side lower limb mechanism; and the affected side shoe body and the healthy side shoe body are respectively provided with a plurality of foot pressure sensors, which are coupled to the control module, and the control module drives the first drive device and the second drive device accordingly based on the torque angle sensing element, the trajectory measurement module and the measurement values ​​of the foot pressure sensors.

3. Development and on-demand auxiliary control of the modular, multifunctional unilateral lower limb rehabilitation exoskeleton system as described in claim 1, wherein, At least one of the thigh exoskeleton module and the calf exoskeleton module is further provided with a length adjustment module in the axial direction, for adjusting the length of the thigh exoskeleton module or the calf exoskeleton module respectively.

4. Development and on-demand auxiliary control of the modular, multifunctional unilateral lower limb rehabilitation exoskeleton system as described in claim 1, wherein, The control module uses an Adaptive Proxy-Based Sliding Torque Controller (APSTC-FRLESO) strategy based on a Finite-Time Reduced-order Linear Extended State Observer (FRLESO) to drive the first and second drive devices.

5. The modular multifunctional unilateral lower limb rehabilitation exoskeleton system development and on-demand auxiliary control as described in any one of claims 1 to 4, further comprising an auxiliary support device correspondingly disposed at one end of the healthy lower limb mechanism, the auxiliary support device comprising a rod, the rod being provided with a transmission module and an inertial sensing unit, the inertial sensing unit being used to measure the posture of the rod and connected to the transmission module, the transmission module being connected to the control module; and at least one pressure sensor being provided at the bottom end of the rod, the pressure sensor being connected to the transmission module; the transmission module transmitting the measurement values ​​of the inertial sensing unit and the pressure sensor to the control module, enabling the control module to assist in correspondingly driving the first driving device and the second driving device.

6. Development and on-demand auxiliary control of the modular, multifunctional unilateral lower limb rehabilitation exoskeleton system as described in claim 5, wherein, The control module uses the AAN (Assist-as-needed) algorithm to estimate a required torque and uses the measurements from the inertial sensing unit, torque angle sensing element, and the status of the first and second drive devices to provide feedback to the controller of the torque of the first and second drive devices.

7. Development and on-demand auxiliary control of the modular, multifunctional unilateral lower limb rehabilitation exoskeleton system as described in claim 6, wherein, The control module uses the AAN algorithm to compensate for the errors in the affected lower limb mechanism and the healthy lower limb mechanism, thereby controlling the speed of the first drive device and the second drive device.

8. The modular multifunctional unilateral lower limb rehabilitation exoskeleton system development and on-demand assistive control as described in any one of claims 1 to 4, further comprising a motion intention recognition device connected to the control module, wherein the control module uses the motion intention recognition device to sense the intention and provide corresponding feedback to control the first drive device and the second drive device.

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