Design, modeling, and control of a reconfigurable rotary series elastic actuator with nonlinear stiffness for assistive robots

Qian，Yuepeng1,2; Han，Shuaishuai1; Aguirre-Ollinger，Gabriel1; Fu，Chenglong2; Yu，Haoyong1

2022-10-01

10.1016/j.mechatronics.2022.102872

MECHATRONICS   Impact Factor & Quartile

0957-4158

In assistive robots, compliant actuator is a key component in establishing safe and satisfactory physical human–robot interaction (pHRI). The performance of compliant actuators largely depends on the stiffness of the elastic element. Generally, low stiffness is desirable to achieve low impedance, high fidelity of force control and safe pHRI, while high stiffness is required to ensure sufficient force bandwidth and output force. These requirements, however, are contradictory and often vary according to different tasks and conditions. In order to address the contradiction of stiffness selection and improve adaptability to different applications, we develop a reconfigurable rotary series elastic actuator with nonlinear stiffness (RRSEAns) for assistive robots. In this paper, an accurate model of the reconfigurable rotary series elastic element (RSEE) is presented and the adjusting principles are investigated, followed by detailed analysis and experimental validation. The RRSEAns can provide a wide range of stiffness from 0.095 N m/ to 2.33 N m/, and different stiffness profiles can be yielded with respect to different configuration of the reconfigurable RSEE. The overall performance of the RRSEAns is verified by experiments on frequency response, torque control and pHRI, which is adequate for most applications in assistive robots. Specifically, the root-mean-square (RMS) error of the interaction torque results as low as 0.07 N m in transparent/human-in-charge mode, demonstrating the advantages of the RRSEAns in pHRI.

Assistive robots Nonlinear stiffness Physical human–robot interaction (pHRI) Reconfigurable series elastic element Series elastic actuator (SEA)

SCI ; EI

English

Others

Agency for Science, Technology and Research[192 25 00045];Agency for Science, Technology and Research[192 25 00054];National Natural Science Foundation of China[U1913205];

Automation & Control Systems ; Engineering ; Robotics

Automation & Control Systems ; Engineering, Electrical & Electronic ; Engineering, Mechanical ; Robotics

WOS:000864746000004

PERGAMON-ELSEVIER SCIENCE LTD

20223012420359

Actuators ; Elasticity ; Frequency response ; Human robot interaction ; Machine design

Mechanical Design:601 ; Robotics:731.5 ; Control Equipment:732.1 ; Materials Science:951

ENGINEERING

2-s2.0-85134816334

Scopus

1.Department of Biomedical Engineering,National University of Singapore,Singapore,117583,Singapore
2.Guangdong Provincial Key Laboratory of Human-Augmentation and Rehabilitation Robotics in Universities,Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Qian，Yuepeng,Han，Shuaishuai,Aguirre-Ollinger，Gabriel,et al. Design, modeling, and control of a reconfigurable rotary series elastic actuator with nonlinear stiffness for assistive robots[J]. MECHATRONICS,2022,86.

Qian，Yuepeng,Han，Shuaishuai,Aguirre-Ollinger，Gabriel,Fu，Chenglong,&Yu，Haoyong.(2022).Design, modeling, and control of a reconfigurable rotary series elastic actuator with nonlinear stiffness for assistive robots.MECHATRONICS,86.

Qian，Yuepeng,et al."Design, modeling, and control of a reconfigurable rotary series elastic actuator with nonlinear stiffness for assistive robots".MECHATRONICS 86(2022).