Theoretical Research And Structural Design Of Magnetostrictive Tactile Sensor

With the development of robotics,simple structure,high sensitivity and high accuracy are required for sensor technology.Among them,tactile sensor is an important way for robots to obtain external information,which is widely used in electronic skin,industrial gas detection and other fields.Currently,piezoelectric sensors,pressure-volume sensors,piezoresistive sensors and other tactile sensors have been proposed.Although piezoelectric sensors are simple in structure,their ductility is poor.Piezoresistive sensor is easy to prepare,but its sensitivity is low.Capacitive sensor is not affected by temperature,but the measurement circuit is more complicated.Based on the Jiles-Atherton model,this paper optimally solved it,combined with cantilever magnetostrictive tactile sensor and Fe-gallium alloy to optimize the existing magnetostrictive tactile sensor structure,and verified it using COMSOL software.COMSOL software is used for verification.Ferrogallium alloy sheet in magnetostrictive sensor generates magnetization under the magnetization of external magnetic field.Hysteresis loop is a curve describing magnetization under the action of external magnetic field of different strengths,and the J-A model is a mathematical model describing the hysteresis loop of different materials.In order to improve the accuracy of the mathematical model of the tactile sensor,this paper first summarizes and modifies the J-A model.The influence of parameters in the J-A model on hysteresis loop was obtained by simulation.A new mathematical calculation method was proposed for parameter k,and the calculation formula was verified.All the parameters in the J-A model are required by the mathematical model and simulation of the tactile sensor.However,it is easy to diverge and not converge when solving by formula method,and easy to fall into the local optimal solution when solving by meta-heuristic algorithm.In this paper,L-WOA algorithm is proposed by combining whale optimization algorithm with Levi’s flight algorithm to improve problems such as slow convergence and easy to fall into the optimal solution in the late period of whale algorithm.In addition,C-LWOA algorithm is proposed by combining the physical meaning of J-A model parameters and the new calculation method of parameter k.The algorithm improves the calculation accuracy by reducing the search dimension and scope,and is verified by literature data and experimental data.Based on the classical magnetostrictive cantilever sensor,a new type of magnetostrictive tactile sensor was optimized,and the corresponding relationship between the voltage U of the sensor and the external stress F was deduced by combining the theory of material mechanics,electromagnetics and piezomagnetic equation.The magnetic field simulation of the model was carried out by finite element analysis,and the number and position of permanent magnets and the size of fe-gallium sheet were determined.