Design and Implementation of a Self-Calibration Method for a Dual-Arm Haptic Device

摘要

Existing surgical robotic systems for laparoscopic procedures mainly utilize a teleoperation paradigm. In this paradigm, a dual-arm haptic device installed at the master console is used by an operator to give motion commands. To convey the operator's intent precisely, a calibration process for the haptic device is essential. Different from the traditional calibration methods of using external measuring equipment, a self-calibration method for such a dual-arm haptic device, the ParaMaster, is proposed in this paper. First, a fiducial connector is designed to connect the 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> link of the left ParaMaster and the 4th link of the right ParaMaster so that a closed-loop kinematic chain is formed. Using the constraints introduced by the connector, a calibration model is then formulated. In this model, only the data from the internal encoders of both devices is utilized. To reduce the variance of the estimated parameters, both the parameter identifiability and calibration pose set selection are analyzed. Finally, the effectiveness of the proposed self-calibration method was verified through both a simulation study and a calibration experiment. After the calibration, the average end-position errors of the left and right ParaMasters were 0.25 mm and 0.27 mm, respectively.