Performance Analysis And Experiment Research For Six-axis Heavy Force Sensor Based On Stewart Structure

The giant heavy operating equipment is urgently needed in the high-efficiency and high-precision manufacturing of huge parts. During the course of manufacturing, coordinated manipulation is needed between operating equipment and manufacturing equipment. Terminal actuator for operating equipment has compliance of force and position according to the part deformation in manufacturing. Real-time six-axis heavy force measurement is the basis of multi-degree of freedom coordinated control, so there is significant meaning to study six-axis heavy force measurement in extreme environment. Only single-dimension measurement is available for the force range between 100KN and 100MN at present, and present six-axis force sensor only is limited to measurement of small-range force. Thus, it's key condition for realizing six-axis heavy force measurement to solve the contradiction between heavy carrying capacity and multi-dimension force measurement.Static mathematical model for six-axis heavy force sensor based on Stewart structure is built according to measurement principle of six-axis heavy force sensor based on Stewart structure and heavy force load sharing measurement mechanism, and the inner relationship between the sensor measurement accuracy and the condition number of the static first order coefficient matrix is obtained through analyzing heavy force sensor measurement error. Through the analysis of static first order coefficient matrix and flexibility matrix of the force and moment, the isotropy performance indices and the sensitivity are obtained, as well as the relationship between the isotropy performance indices and the structure parameters of the sensor. Change regularity for static performance indices and structure parameters of six-axis heavy force sensor is obtained by utilizing space model theory and atlas analysis method according to different performance indices. In addition, genetic algorithm is used to optimize the structure parameters of new-type six-axis heavy force sensor and the structure design of six-axis heavy force sensor based on Stewart structure is finished. Lastly, static calibration experiment for new-type six-axis heavy force sensor based on Stewart structure is performed on the special calibration-loading device and calibration curves of sensor and experiment decoupling matrix are obtained.In this paper, the feasibility of designing and optimizing the structure of six-axis heavy force sensor by utilizing atlas analysis method and genetic algorithm is verified through analyzing the static performance indices of six-axis heavy force sensor based on Stewart structure; And it is verified that six-axis heavy force sensor has well-behaved measurement precision through static calibration experiments. The paper will provide theory reference for fast, highly accurate and coordinated control of the giant heavy operating equipment.