Torque-Sensorless Control of Stepper Motors for Low-Cost Compliant Motion Generation
Journal
IEEE Access
Journal Volume
9
Start Page
94495
End Page
94504
ISSN
21693536
Date Issued
2021
Author(s)
Abstract
Actuators that can generate controllable compliant output motion are suitable for robots that need to interact safely with humans or the environment. To obtain the accurate output torque required to control the compliant motion, existing robotic actuators use one or more sensors to measure the deformation of a stiff or compliant element between the actuator and the output. The complexity, reliability, and cost of sensors are the current challenges. Deformation-based sensing also suffers from limited bandwidth and stability range. This paper proposes a torque-sensorless control method of stepper motors to generate compliant motion. Stepper motors are used because of their low cost and reliability. They also have a much higher torque-to-weight ratio and torque-to-rotor-inertia ratio than other DC motors. Torque and impedance controllers based on stepper motor current feedback are developed. Torque-sensorless impedance, and gripping force control experiments are provided to show the advantages of the proposed method. It is expected that the new control method for stepper motors can offer a competitive alternative when cost, stability, or bandwidth of complaint actuators are the major concerns.
Subjects
Compliant Motion
Friction Compensation
Gripping Force Control
Harmonic Drive
Phase Current
Stepper Motor
Torque-sensorless Control
Actuators
Bandwidth
Costs
Dc Motors
Deformation
Motion Control
Stepping Motors
Torque
Torque Control
Complaint Actuators
Compliant Motion
Control Experiments
Control Methods
Impedance Controllers
Limited Bandwidth
Robotic Actuators
Sensorless Control Method
Sensorless Control
SDGs
Publisher
Institute of Electrical and Electronics Engineers Inc.
Type
journal article