Design of a Custom Compact Actuator for Pediatric Rehabilitation Exoskeleton Robots

Reducing the volume and weight of actuators is crucial for exoskeletons designed for children with cerebral palsy. However, few studies have been conducted to develop dedicated actuators for the exoskeletons of children. Most studies have used a combination of commercial motors and reducers, resulting in a lack of integration and making it difficult to meet the requirements for compactness. Therefore, this study explores the design practices of a custom compact actuator for pediatric rehabilitation exoskeletons and presents an actuator with high torque density and control bandwidth. The compactness of the actuator is improved by fully integrating the two-stage reducer into the motor stator. The motor and reducer of the actuator are designed and simulated using finite element analysis to ensure electromagnetic and mechanical reliability. The customized control hardware and control method of the actuator are also presented. Finally, the actuator prototype is subjected to system identification and load-characteristic tests. The experimental results demonstrate that the actuator has the advantages of a small size, high torque density, and good dynamic performance.