A Power-Assisted Cart with the Optimal Assistance Ratio and Disturbance Observer-Based Methods for Walking Assistance Applications

Abstract

In this paper, we propose two control methods for driving a power-assisted cart made for walking assistance for the elderly. The optimal assistance ratio (OAR) and disturbance observer-based (DOB) methods properly adjust the motor output of the cart with high operational efficiency in response to changes in the environment. Healthy subjects walked with the cart on several road surfaces under various conditions, and the experimental results indicate the high operational efficiency of the two proposed methods. Meanwhile, their drawbacks are also discussed herein. The two methods can be used separately or combined according to the application. The OAR method is more suitable for indoor use, while the DOB method is applicable for outdoor applications. Combining these two methods could overcome the mentioned drawbacks.

Adaptive Mode-switching From Autonomous Driving Mode to Manual Operation Mode of Mobile Robot Based on Body Sway

“…Considering the relationship between the operator and AMR, the introduction of a power-assisted manual operation mode, in which the operator directly touches the AMR to adjust the stopping position and/or change the target motion, in addition to autonomous operation, can help in achieving greater flexibility in the use of AMRs. Force sensors are typically employed to measure the operation force in power-assisted manual operation control of machines [8,9]. Because this type of sensor is typically expensive and fragile, it is unsuitable for use in AMRs that are deployed in large numbers in factories.…”