Development Of Piezoelectric Six-axis Force Sensor On Axis With Four-pivot

The development degree of giant heavy-load manufacturing equipment stands for the national manufacturing ability and the manufacturing level, which is important for the national economy and national defense security. It is a technical challenge for the design of heavy-load manufacturing equipment that how to ensure the operational capability in the whole work space and speed capability of equipment working under extreme operating conditions. In the working process of heavy-load operation equipment, the six-axis force measurement and real-time feedback are not only the basis of achieving the coordination of operational control and force-response control, but also important for the planning and adjusting in forging process. In order to achieve feedback control, the measurement of six-axis is needed. The technology difficulty is how to solve the contradiction between large carrying capacity and high sensitivity force measurement.This project is funded by 973 Project of China (No.2006CB705406). From the application aspect of engineering, interdisciplinary knowledge, such as Physics of Crystals, Physics of Dielectrics, Piezoelectricity, Theory of Elasticity of an Anisotropic Body, Electromagnetics is utilized in the investigation on design and manufacture. On the basis of theory analysis, the key dimensions and dynamic characteristic of the six-axis force sensor are designed and analyzed according to its specialty and applied demandIn this paper, a six-axis force sensor is designed with structure of parallel mechanism. At the same time, a new-style special holding device is designed for the six-axis force sensor. The specific work is as follows.A relatively rational spatial layout of the form of force-sensitive element is proposed, and its mathematical model is built and solved. Through analyzing longitudinal and shearing piezoelectric effect of quartz crystal, the combination of force-sensing element is identified, that is two yx crystal groups and one xy crystal group. A four-pivot model is determined through the research which investigates the spatial layout of multi-pivot force sensitive components and analyzes the mechanical models. The corresponding six-axis force sensor is designed and fabricated.A new-type holding device used to connect the axis and the six-axis piezoelectric quartz force sensor rigidly is designed. The model is analyzed by ANSYS software, and then the main parameters are determined. As the same time, the special calibration scheme is designed, and the static and dynamic calibration experiments are carried out.The experimental results show that the six-axis piezoelectric force sensor has good quality and good dynamic performance. The non-linearity error is less than 0.710%, repeatability error is less than 0.532%, the interference is within 4.28% and the hysteresis error is less than 4.552%.Therefore, the indexes of the six-axis piezoelectric quartz force sensor reach to the standards of CIRP - STCC on dynamic dynamometer completely.