Study On The Calculation Method Of Three-dimensional Force Sensor Calibration

In recent years, with the development of electronic technology such as semiconductor micro fabrication, the research on three-dimensional force sensor has been developed quickly at home and abroad. The calibration of a three-dimensional force sensor is one of the important links in engineering test.In recent years, with the development of electronic technology such as semiconductor micro fabrication, the research on three-dimensional force sensor has been developed quickly at home and abroad. The calibration of a three-dimensional force sensor is one of the important links in engineering test.In domestic at present in terms of calibration algorithm for three-dimensional force sensor, both at the same time to consider three strain sensor beams are orthogonal, and at the same time, considering the three-way deformation coupling relationship is still relatively less. The paper starts from the abstract three inputs and three output mathematical models and established the three-dimensional force sensor's general mathematical model. Then unfold the model as a first-order Taylor-series and ignore Lagrange remainder term as a system error in this study, get the three-dimensional force sensor's canonical equations which used to calculated linear calibration. Take the one-way repeated loading in three directions respectively, and used the least square method to fit the output data corresponding to the load, after comparing the fitting result with the original canonical equations can determine its coefficient matrix, finally derived the calibration algorithm; Using the least squares method to fit the results calculated by the calibration algorithm corresponding to the square of the difference of actual load to calculate the calibration coefficient matrix of system error, plug in the calibration formula can get the system error of the calibration algorithm. In order to verify the calibration algorithm is feasibility in theory, the paper will put a concrete example data processing, it can draw numerical examples of specific calibration algorithm and the example of the system error, and found that the algorithm is feasible and the effect of the system error of examples, but the algorithm still exist certain errors, so the paper also analyses every possible cause of the algorithm error and puts forward the method to improve and avoid. Finally designs a universal three-dimensional force sensor to carry on the calibration experiment, and it is concluded that a series of calibration data, using the proposed to calculate the calibration results and compared with the experimental results, the results show that the proposed algorithm has certain availability and calibration accuracy.The calibration just assumes the three strain beam of sensors is orthogonal during the deriving of this algorithm, and taking up the three deformation coupling relationship at the same time, without limit the specific structure of sensor, thus the algorithm is universal for three-dimensional force sensor with different structure. The algorithm provides a new train of thought and research methods for the calibration of multi-directional coupling type sensor.