Precise and stable feedback for haptic device with exact dynamics and optimal estimation

In this paper, we propose a force feedback scheme for Delta device to improve precision and stability in master-slave teleoperation. A simple and exact dynamical equation is created with principle of virtual work, which is easy to calculate in real-Time. After analysing three items deep in dynamical equation, a reasonable strategy is designed to identify the mass of Delta mechanism. The identified parameters and dynamical equation are verified correct in ADAMS and MATLAB softwares. Simultaneously, following previous work on haptic interface, a suitable Kalman Filter algorithm is proposed to attain smooth contact force in real-Time based on the impedance of environment, and simplified due to the short period of a cycle. Finally, a whole master-slave system is set up with CHAI3D toolkit, which consists of Phantom Omni, Computer and Delta device. With a force sensor mounted on the end, the contact force is measured in practice and then filtered with proposed algorithm. The final result shows that the estimated curve followed measured data well and lied at the center of original curve.