Haptic Feedback Interface based on Cascade Admittance-Impedance Controller

Author(s)

Ostan, Icaro ; Goncalves Siqueira, Adriano Almeida ; IEEE

• Document type: Journal article
• Source: 2022 9TH IEEE RAS/EMBS INTERNATIONAL CONFERENCE ON BIOMEDICAL ROBOTICS AND BIOMECHATRONICS (BIOROB 2022); v. N/A, p. 6-pg., 2022-01-01.

Abstract

Assistive technologies are fundamental to improve the recovery and quality of life of individuals impaired by temporary or long-term disabilities. In that sense, rehabilitation robotics and virtual reality act together to accomplish a more efficient and engaging physical therapy practice. To achieve these benefits, robotic devices must deliver, ideally, both movement assistance and haptic feedback, although, in reality, most assistive robots were designed to deliver assistance only. By means of the proper control architecture, already existing robots may function as haptic devices to achieve more immersive experiences. In this case, to adapt assistive robots, instead of building new ones from sketch, seems to be a practical and feasible approach. This work proposes a control architecture which handles the human, robot and environment interaction through a cascaded admittance-impedance controller. Tests showed that the proposed controller is capable of delivering movement assistance and haptic feedback, and that it retains the impedance controller performance by modulating the desired trajectory in order to account for the environment forces. Tests with ten healthy subjects suggested that the proposed controller ensures the expected robot behavior, but there must be other factors affecting the overall user experience, since, statistically, the subjects could not distinguish from the moments the robot was providing haptic feedback besides the assistance. (AU)

• FAPESP's process: 19/05937-7 - Hybrid adaptive strategies for lower limb exoskeletons
• Grantee: Adriano Almeida Gonçalves Siqueira
• Support Opportunities: Regular Research Grants