Asservissement en position d'un manipulateur robotique pour l'échographie 3D des artères des membres inférieurs

Abstract

Peripheral arterial disease requires a three-dimensional representation of the blood vessels for the diagnosis, the location and the treatment of the stenosis. Three-dimensional ultrasound imaging is a non-invasive and low cost alternative to conventional imaging systems. This 3D reconstruction can be obtained by combining planar ultrasound images where their positions are known. The robot ETS 3D-US of École de technologie supérieure is designed to follow this method by moving the probe in contact with the patient to capture images and their positions. This thesis presents the design and implementation of a first-level position control system for this robot. With modeling of the robot, low operating speed and high-ratio gearbox, the control law through computed torque is linear and decoupled. The computed torque control law is combined with a proportional–integral–derivative (PID) controller. Experimental results show a control with accuracy of 0.5 mm in position and 0.3° in orientation estimated from the motors’ position. This satisfies the precision requirements of an examination. Therefore, we can conclude this approach is a valid first-level position controller if the mechanical robot structure has small geometric errors. Hence, a geometric calibration will be needed to ensure adequate accuracy.

Date	28 Apr 2011
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Pascal Bigras (Supervisor) & Ilian Bonev (Co-supervisor)