Study Of Parallel Piezoelectric Six-axis Heavy Force Sensor

The huge heavy-load operation equipment is the basic equipment in manufacturing industry chain, embodies a country's ability of extreme manufacture, it is a kind of huge industry robot used under the condition of extreme load, it can actualize multi-positional operation. During the operational process of operation equipment, measurement of six-axis force and real-time force feedback is the base of cooperative operation control and comformable control of multiple equipments.The technology of heavy force measurement developed under the need of heavy-load equipment, and commonly force sensors whose carrying capacity is in the range of 10~2000kN is called heavy force sensor, while the rated load of force sensor used on heavy-load operation equipment may reach 100MN. In order to actualize force feedback control, measurement of six-axis heavy force is needed. The contradiction of heavy load and multiple force measurement should be resolved. A method of parallel load distribution is put forword in the paper, and piezoelectric quartz is used as measuring sensitive element to measure dynamic 6-axis force on operation equipment's arm.First, this paper analyzes and compares all kinds of heavy load measuring technologies and multi-axis force measuring technologies, introduces the principle of piezoelectric force measurement and method of multi-axis force measurement using piezoelectric sensor.Second, the paper analyzes the principle of parallel load distribution and 6-axis force measurement of piezoelectric sensor. The principle of parallel load distribution is using parallel mechanism to proportion the load on sensor's sensitive element to the total load applied on measurement device. Quartz groups are evenly arranged by square on measuring plane, the value and direction of six-axis force could be obtained through experimental decoupling.Third, with the method of finite element analysis and experiments, the paper studies principle of parallel load distribution of piezoelectric multi-axis force sensor in depth, and figures out the influence of sensor's structure dimensions on sensor's load distribution ratio in each direction. By means of experiments, load distribution experimental device performs well in load distribution and line output. According to the results of analyses and experiments, it could be known that the parallel load distribution mechanism is qualified to measure multi-axis heavy force. Fourth, this paper designs the quartz groups and body structure of piezoelectric six-axis heavy force sensor, and analyzes the structure with ANSYS. By changing dimensions of sensor's finite element model, the relationship between sensor's load distribution ratio and its dimensions has been known. And load is applied on each direction of sensor' model, the transfer function of input and output has been got.Finally, a six-axis force measuring experimental device is designed, and a load is applied on each direction of the device. The results of the experiments show that this device can do well in measuring six-axis force and line output.