Error Analysis And Experiment Research On Flexible Hinge Parallel Six-dimensional Force Sensor

In recent years,the six-dimensional force sensor based on flexible parallel mechanism has been paid more and more attention because of its high measurement accuracy.However,it is inevitable that the manufacturing and working process will inevitably cause the geostationary error,seriously affect the sensor accuracy,linearity,sensitivity and other static performance indicators,making it difficult to meet the precise measurement of the working environment.Based on the engineering practice,the error factors of the flexible hinge 6-UPUR six-dimensional force sensor mechanism is discussed,and the static calibration experiment is carried out to verify it.The main research is as follows:Firstly,the error model of sensor manufacturing is deduced by Denavit-Hartenberg(hereinafter referred to as DH)modeling method,and the error sources are mapped into four types of DH parameters by means of dummy motion pair.For the main error sources The radius error of the fixed platform,the spacing error of the two motion axes of the middle Upair and the lower positioning block U,and the installation error of the single-dimensional force sensor)are analyzed by the Monte Carlo method.Secondly,based on the theory of Euler-Bernoulli beam and the hypothesis of small deformation,the flexibility matrices of the two R-pair used by the sensor are given.By using the deformation superposition principle of the flexible tandem branch and the deformation coordination condition of the parallel combination,the sensor The stiffness matrix is established,and the finite element analysis software ANSYS Workbench is used to analyze the static force of the sensor,and the change of the dynamometer platform caused by the change of the force is obtained.The results were compared and analyzed.Thirdly,the mechanical model of the six-dimensional force sensor based on the parallel mechanism is given,and the error of the sensor machining and the calibration error are integrated.The definition of the sensor precision and other static performance indexes is given,and the ideal situation and the Error under the two cases of comparative analysis,the error on the static performance of the sensor.Finally,the static calibration experiment is carried out to obtain the calibration matrix and the error matrix calculated by the least squares decoupling.The laser deformation is used to detect the structural deformation during the sensor calibration process,and then the sensor is tested in three cases.Order static influence coefficient matrix,and provide guidance for the optimization of flexible parallel six-dimensional force sensor parameters.