Pseudo-Sensorless High-Performance Bilateral Teleoperation by Sliding-Mode Control and FPGA

This paper proposes a pseudo-sensorless implementation of scaled bilateral teleoperation. It is based on Hall effect sensors that are built within the motor housing. The proposed implementation requires no external sensor that can deteriorate system dynamics and performance. The integrated sensors have been used both for position measurement and external force estimation that are necessary in high-performance bilateral teleoperation. Nevertheless, system perturbation dynamics may always appear in a practical mechatronic system. Therefore, the chattering-free sliding-mode control algorithm is applied that ensures robustness toward the disturbances, and yet is easy to implement. The data acquisition algorithms as well as the control algorithm are implemented by field-programmable gate array (FPGA) in order to provide high control rate that can further increase robustness required for haptic fidelity of the system for scaled teleoperation. The applied algorithms along with the FGPA implementation were validated by the 2-DoF experimental system. It has been shown that the proposed pseudo-sensorless implementation by FPGA provides high bilateral teleoperation performance.