Design Of Magnetostrictive Array Tactile Sensorand Experimental Research

Intelligent robot work in complex environment needs a variety of sensors to cooperate with each other accurately.As an important perception form next to vision,touch plays an important role in the process of information interaction and sensor cognition.As the core of tactile sensing technology,tactile sensor needs to be researched in design,manufacture and output characteristics.The existing tactile sensor composed of a single sensitive element can not obtain static and dynamic tactile information accurately at the same time.Based on the piezomagnetic effect,two new tactile sensing units are designed and fabricated by using the filiform iron gallium magnetostrictive material,which can obtain the static and dynamic tactile information at the same time,and integrate them to form an array structure,which can be used to test the grasping force of the manipulator and the rigidity of the object.Firstly,the structure of magnetostrictive tactile sensing unit is designed based on the biological sensing principle,combined with the biological sensing mechanism and the characteristics of magnetostrictive materials.The working principle of the sensing unit is analyzed,and it is formed into an array.Based on the magnetostrictive linear constitutive equation,the test force model of magnetostrictive tactile sensor unit is established.According to the method of controlling variables,the best bias magnetic field of Fe GA wire is 1.908ka/m,and the effects of pressure,length and diameter of Fe GA wire on voltage output are measured.The output characteristic of the sensor unit is calculated,and the experimental results are compared with the theoretical results.The output characteristics of the magnetostrictive tactile sensor array are tested respectively,and the influence of the magnetic field between the sensor arrays is simulated and analyzed,and the most suitable distance between the array units is obtained.The magnetostrictive tactile sensing unit and array prototype are made,and the tactile sensing unit test system is built.The static force and dynamic force of the sensor unit are tested,and the sensitivity of the sensor unit to measure the force is obtained.The sensor has a good response and a good sensing accuracy to the dynamic force in the frequency range of 1-4hz.Based on the tactile sensor test system,an experimental method is designed to test the stiffness of the object,and a test stiffness model is established,which can be used to describe the relationship between the output voltage of the sensor and the grasping force and the stiffness of the object.The estimated stiffness of different objects is obtained by analyzing the output voltage of the sensor.The stiffness of different parts of the same object can be measured at the same time by using the sensor array.As a result,the surface sensor array can perceive more information than a single sensor.