Study On Three-dimension Fingertip Force Sensor And Biomimetic Whisker Sensor

Besides the need for multiple degrees of freedom manipulator,the space cabin is responsible for the precision operation of the space station,which needs to be designed with five high imitation degree dexterous fingers.The three-dimensional fingertip force sensors are arranged at the fingertip and the joint of each finger of the manipulator to achieve the above functions,to realize the function of auxiliary force compliance dexterous manipulator operating process control,to ensure the smooth operation of space.According to the application background and technical indicators,and on the base of theory and experiment in our laboratory for many years study of multidimensional force sensor,this thesis designed a new type of elastic body structure,which combines the traditional beam structure with the central straight beam structure.The static structure of the elastomer structure of the sensor is simulated by means of finite element analysis tool ANSYS.Based on the analysis,the structural dimensions of the elastomer are optimized,at the same time,the final size of the elastic structure and the best paste position of the strain are determined.According to the measurement requirements,the strain bridge circuit is designed to measure the force in each direction,converting the force signal into a voltage signal.Due to the output signal of the bridge circuit is very weak,it is necessary to amplify and filter the voltage signal in order to collect the stable voltage signal.The amplified signal is transmitted to the host computer through the data acquisition card NET2801,and the data acquisition and real-time display are realized by the data acquisition software.In order to improve the characteristics and accuracy of the sensor,a calibration device for small sensor is designed.The calibration experiment of the sensor is carried out by using the method of loading standard weights.Two decoupling methods are discussed in detail,one is the decoupling algorithm based on the inter dimensional coupling error and the piecewise two order fitting model,and the other is based on the BP neural network static nonlinear decoupling,and the decoupling accuracy of the two algorithms is compared with the calibration data.The results show that the decoupling accuracy of algorithm 1 is 2.101%and the decoupling accuracy of algorithm 2 is 1.235%.The design of the fingertip force sensor meets the technical requirements,moreover,algorithm 2 has higher decoupling accuracy than algorithm 1.Then,according to the obtained decoupling coefficient,the data acquisition software of the host computer was modified to realize the self decoupling of the software for decoupling algorithm 1,convert the collected voltage value into force,and display it in real time and save it automatically.Finally,based on the fingertip three-dimensional force sensor,a flexible carbon fiber rod was used as a whisker to fabricate biomimetic whisker sensors.Displacement measurement theory is analyzed and experiments are carried out to verify the sensor in the end.