A Torque-Controlled Actuator With High Rigidity and Low Aspect Ratio
Journal
IEEE/ASME Transactions on Mechatronics
Journal Volume
27
Journal Issue
6
Start Page
5572
End Page
5582
ISSN
10834435
Date Issued
2022
Author(s)
Abstract
To ensure safe and accurate environment-robot interaction, a torque sensor is usually mounted at the output of an actuator to detect and control the output torque. Deformation-based sensors at the actuator output would significantly increase the actuator size and complexity while decreasing the output rigidity in off-axis directions. To reduce the extra complexity, space, and output compliance required for torque sensing, this article proposes a torque-controlled actuator that does not rely on deformation-based sensing at the actuator output. Instead, a torsion spring is mounted at the input of the harmonic drive. Encoders are used to sense the spring deformation to control the output torque with low sensing noise. Hence, the size of the actuator can be minimized while the output rigidity can be maintained. Using the torsion spring can also significantly reduce the reflected output inertia of the actuator. Experiments are provided to demonstrate torque control accuracy and bandwidth. Position control results also show a comparable response to actuators that do not have torque sensors. This new torque-controlled actuator can provide a more competitive solution for collaborative robots to interact with humans or the environment.
Subjects
Harmonic Drive
Position And Torque Control Bandwidth
Series Elastic Actuator
Torque-controlled Actuator
Torsion Spring
Virtual Stiffness Rendering
Aspect Ratio
Bandwidth
Deformation
Position Control
Rigidity
Robots
Torque
Torque Control
Torque Meters
Torsional Stress
Control Bandwidth
Harmonic Drive
Position And Torque Control Bandwidth
Robot Sensing System
Series Elastic Actuators
Torque Sensors
Torque-controled Actuator
Torsion Springs
Virtual Stiffness
Virtual Stiffness Rendering
Actuators
SDGs
Publisher
Institute of Electrical and Electronics Engineers Inc.
Type
journal article