Design of miniature parallel manipulators for integration in a self-propelling endoscope

This paper presents two designs for a miniature robotic manipulator that has to be integrated into a self-propelling endoscope. The endoscope is meant to inspect and intervene in the human colon through which it moves by inchworm locomotion. Both manipulator designs are based on a 3-degree-of-freedom (dof) Stewart platform, either driven by hydraulic pistons or by electromagnetic motors. The hydraulic manipulator is 12 mm in diameter and 30 mm long. It has a stroke of 10 mm and tilts 30-35 degrees. The system is designed to be used at pressures up to 10 bar at which each piston generates a force of 7 N. Piezoelectric and electromagnetic valves are developed that will be integrated into the manipulator. The electrical platform has three telescopic legs driven by a motor-spindle combination. This manipulator has a length and diameter of respectively 50 and 15 mm, and generates speeds up to 5 mm/s and forces up to 1.2 N per leg. (C) 2000 Elsevier Science S.A. All rights reserved.