Research On Flexible Pressure/Temperature Composite Tactile Sensor For Hydropower Station Inspection Robot

Equipment inspection is an important guarantee in the normal operation of hydropower stations.With the introduction and advancement of "smart hydropower stations",intelligent inspection robots have become a trend to replace manual inspections.As a device that can be used in intelligent inspection robots to measure object characteristic information,tactile sensors can detect information such as pressure and temperature changes caused by vibration when hydropower units are working,and realize a new working mode of intelligent inspection of hydropower stations.This idea provides a new direction for research.In order to more comprehensively detect the characteristic information of the operating environment of the hydropower unit,and overcome the problems that the traditional tactile sensor can only measure the single information of the object and cannot work in a flexible bending state,this paper proposes a flexible composite tactile sensor with both pressure and temperature detection capabilities.First,the overall structure of a flexible composite tactile sensor is designed,in which the capacitive pressure sensing part includes a PI flexible substrate,a patterned Ag electrode layer,and a porous PU intermediate dielectric layer;the thermocouple temperature part includes a PI flexible substrate,a Cu positive electrode,Cu Ni negative electrode.Secondly,perform finite element simulation on the pressure part of the capacitor to explore the relationship between pressure-capacitance and capacitancetemperature.According to the designed structure,a flexible composite tactile sensor composed of a capacitive pressure sensing unit and a thermocouple temperature sensing unit is prepared by using MEMS technology.The experimental results show that the flexible composite tactile sensor is fully flexible;the sensitivity of the capacitive pressure sensing part reaches 23.62%/N,the range is 6N,the response time is 0.1s,and the rebound time is 0.3s.The capacitance and pressure are similar within the range Linear relationship;The adhesion force of the metal electrode of the thermocouple temperature sensing part is about 9.4N.The thermocouple is statically calibrated and fitted with the least square method to improve the accuracy.The calculation shows that the error is ±1℃,which belongs to the second level standard.The flexible composite tactile sensor has been tested with human fingers,and the theoretical temperature is calculated to be 30.81℃,the temperature error is 0.09℃,and the error rate is 0.29%;after the finger is pressed,the corresponding theoretical pressure value is 6.8N,and the pressure error is 0.2 N,the error rate is 2.86%.Finally,the ultrasonic cleaner is used to simulate the operating environment of the hydropower unit before and 30 minutes after the start,and the application test shows that the device is feasible.The experimental results prove that the composite tactile sensor prepared in this paper has good application value.