Design and Analysis of Force/Moment Sensor for a Robot

Abstract

To safely hold an unidentified object by means of an intelligent hand of robot, the hand has to recognize the weight of it. By attaching six-axis Force/Torque (F/T or Force/Moment) sensor to an intelligent robot's hand the weight can be calculated by measuring forces F x , F y and F z . Forces should be measured in order to precisely pull and push an object. To securely grasp an unidentified object with an intelligent robot's gripper, the forces in the gripping direction and in the gravitational direction needs to be detected, but it also requires to perceive the moments to accurately recognize the position of the object in the grippers. A robot joint can be controlled in better way if three forces and three moments exerted at the joint are measured. The available Force/Torque sensors are bulky, not customized and costly. Therefore, it is essential to customize and develop low cost six axis Force/Torque sensor with new appropriate dimensions for an intelligent robot's joints. Six axis Force/Torque sensor is designed using strain gauge. The strain gauges are selected for Aluminium and its working conditions. The sensor design is based on results of parametric analysis done in ANSYS software to obtain the strain values in the measurable range. The analytical results are compared with Finite Element Analysis (ANSYS) results. The percentage error in deviation is 0.75% maximum.