Adaptive Wearable Robots for Movement Assistance via Bio-Inspired Sensorimotor Integration
Motivation: Providing robotic assistance for upper limb mobility in people with motor impairments is a challenging task. To achieve effective assistance, robots must monitor environmental interactions, predict the user’s movements, and dynamically adapt to tasks. This proposal suggests using bio-inspired sensorimotor principles to create soft robots with enhanced perception and adaptability. The aim is to improve users' upper limb movement, especially in daily activities, by developing robots that mimic human muscle function and neural control. The project will advance wearable robot technology, offering safe, effective, and user-controlled assistance for greater independence. The proposed actuator leverages the inherent flexibility of fabric materials combined with a pneumatic network, offering a lightweight, low-cost, and highly adaptable solution for achieving complex bending motions.
Project Highlights:
In this project, we have developed an omnidirectional bending actuator made from soft fabric materials. The actuator design integrates a pneumatic network within a fabric structure, allowing it to bend in various directions when pressurized. Therefore, it offers a lightweight, low-cost, and highly adaptable solution for providing assistance for the shoulder joint.
Figure 1. (a1) Top view of lateral bending: Left bending with one chamber pressurized to 414 kPa, right bending with two chambers at 414 kPa. (a2) Front view showing 360° bending with all chambers pressurized to 414 kPa. (b) Diagram of the OBA, with fabric wale and course directions labeled. (c1) Workspace measurement setup: EM sensor attached to the actuator's free end, with pneumatic and digital connections. (c2) Force measurement setup using a 6-DoF load cell and linear rail, with chambers P1, P2, and P3 labeled.
The design process involved selecting appropriate fabric materials and creating a multi-chambered structure that could be easily inflated and controlled. The characterization of the actuator's performance included tests to evaluate its bending angles, response time, and durability under repeated use. Results demonstrated that the actuator could achieve significant bending angles with precise control over the direction and magnitude of the movement. The fabric-based design also proved to be resilient, maintaining its performance over multiple cycles of operation.
Figure 2. (a, b) Bending and deformation compensation of the OBA: (a1, b1) Horizontal bending without external load. (a2, b2) Out-of-plane deformation with a 100 g payload. (a3, b3) Compensation of deformation by adjusting chamber pressures. (a4, b4) 3D plots of the OBA tip positions during pre-load, post-load, and post-compensation. (c1) 2D load-free workspace of the OBA. (c2) 3D load-free workspace with highlighted actuation paths. (c3) Torque output around the x- and z-axes under varying pressures and chamber configurations.
Refereed Journal Publications
Lee, K., Bayarsaikhan, K., Aguilar, G., Realmuto, J., & Sheng, J. (2024). Design and characterization of soft fabric omnidirectional bending actuators. Actuators, 13(3), 112. https://doi.org/10.3390/act13030112