Multi-connection load compensation and load information calculation for an upper-limb exoskeleton based on a six-axis force/torque sensor

Abstract

In this article, a method of multi-connection load compensation and load information calculation for an upper-limb exoskeleton is proposed based on a six-axis force/torque sensor installed between the exoskeleton and the end effector. The proposed load compensation method uses a mounted sensor to measure the force and torque between the exoskeleton and load of different connections and adds a compensator to the controller to compensate the component caused by the load in the human-robot interaction force, so that the human-robot interaction force is only used to operate the exoskeleton. Therefore, the operator can manipulate the exoskeleton with the same interaction force to lift loads of different weights with a passive or fixed connection, and the human-robot interaction force is minimized. Moreover, the proposed load information calculation method can calculate the weight of the load and the position of its center of gravity relative to the exoskeleton and end effector accurately, which is necessary for acquiring the upper-limb exoskeleton center of gravity and stability control of whole-body exoskeleton. In order to verify the effectiveness of the proposed method, we performed load handling and operational stability experiments. The experimental results showed that the proposed method realized the expected function.

Robotics Perception and Control: Key Technologies and Applications

“…With respect to human-robot collaboration, Wang et al [65] presented a novel approach for compensating load and calculating load information in upper limb exoskeletons using a six-axis force/torque sensor. By measuring the force and torque across the exoskeleton's links and employing a compensator within the controller, this method allows operators to handle varying weights with consistent human-machine interaction forces.…”

“…Multijoint Load Compensation and Load Information Calculation for Upper Limb Exoskeletons [65] Effective load compensation and strength enhancement.…”

IMU-based human activity recognition and payload classification for low-back exoskeletons

“…Payload estimation and compensation could be achieved by exploiting classical inverse dynamics 16 or electromyography 17,18 , or a combination of the two. To achieve this, the exoskeleton needs to be equipped either with force/torque sensors or EMG electrodes, respectively, jeopardizing wearability, task-technology fit, and enduser willingness-to-use, already critical in the industrial context 19,20 .…”

Medical Robotics: Opportunities in China

“…In China, a lower-limb exoskeleton developed by Beijing Ai-Robotics Technology Company was the first to be approved by the CFDA. In addition, the Intelligent Robotics and Technology Response to Active Health and Aging programs funded several projects to address the key technical challenges of power-assisted exoskeletons (82)(83)(84)(85) and orthoses (99) designed to assist people with impaired physical functions. Abbreviation: HMI, human-machine interface.…”