Multi-Axis Force-Torque Sensor

Abstract

A force-torque sensor is the essential sensor in humanoid robots, and it is used to measure interaction between the robot and environment. By measuring the force and torque information at the foot, it is possible to calculate the ZMP (zero moment point), which is the important criterion for the dynamic stability of biped humanoid robot. Force-torque information at the wrist is also useful in manipulation in human environment especially when it interacts with human with its hands. At least four force-torque sensors are required for a full body humanoid robot, but these are the most expensive components. Limited number of companies in global market are providing multi-axis force-torque sensors with extremely high price. If the force-torque sensor is realized at a low cost, humanoid research will be promoted and humanoid robots will be widely used in many fields in the future. To facilitate low-cost development of force torque sensors in humanoid robots, this chapter summarizes several topics such as ZMP concept, strain gauge measurements, electrical interfaces, and some examples of sensors.