Research And Application Of The Readout Approach For Resistive Sensor Array

As a hot topic in recent international research,tactile sensor array,in the form of electronic skin,has been widely adopted in different fields including robotics,medical equipment,hurman prosthese,and wearable devices.Resistive sensor array(RSA)with features of high stability,low cost,simple signal processing circuit and ease of inplcimentation,is widely applied in tactile sensing field.The performance of the RSA depends not only on its preparation tchnology.but also on the features of its readout approach.To achieve low circuit complexity and high measuremtut accuracy,combining with tactile applications,research and application of the readout approach for RSA has been conducted in this paper.Specifically,for reducing circuit complexity,improving measurement accuracy and resistance range,an Improved Resistance Matrix Approach(IRMA)is proposed A joint simulation system based on multi-sofrware is designied for rapid evaluation of the readout approach for RSA.Then,a thermal sensing cushion with flexibility and elasticity is designed and manufactured Finally,a flexible and elastic thermal sensing cusion system based on the IRMA is built,and cortesponding experimental verification are carried outThe contents and acbievements of this work are organized are as follows:1.The existence of the output ports' internal resistance of the microcontroller is verified through the IO port test experiments of STC and STM32,which is about tens of ohms.Multisim simulation results.further show that the measurement accuracy of the Resistance Matrix Approach(RMA)affected by the output ports' internal resistance.Therefore,by adding additional row ADC acquisition chanels based on the RMA,the IRMA is proposed to eliminate the influence of the output internal resistance,finally to improve measurement accuracy and resistance range.2.A multi-software joint simulation system based on LabVIEW,MATLAB,and Multisim is designed for evaluating RSA's performance rapidly.Base.on the correctness of the simulaion resultg,the performance of the RMA and the IRMA,including the ablity to depress the influence of the output ports' internal resistance and adjacent sensing units,measurement accuracy and resiatance range,are simulated.Results show that the influence of the output parts' internal reisisatance of the microcontroller is eliminated in the IRMA,and the IRMA is ess susceptible to adjacent sensing units.Ttherefore,higer measurement accuracy and wider restance range are achieved in the IRMA.3.A thertmistors-bayed sensing cuhion is designed with shared row-column wires.The conductive fabric is evenly curled in the ungrretched elatic abric and fixed at an equal interval with the unstrerehed elastic fabric for placing the thermal-sensing unit,leading to the both flexibility and elasticity of eletrode and the same stretching between adjacent thermal units.Finally a thermal-sensing cushion with soft easticity is achieved.The manufactured thermal-sensing cushion can fit well on the surface of the three-dimensional object and also bas the capability of being stretched4.An IRMA-based flexible thermal sensing cushion systemis designed.Based on the STM32F3 73 microcontroller embedded with 16-bit high-precision ADC and floating processing unit,high-precision voltages on row elerndes and cohun eletrodes are acquired,and rapid solution of the resistance values of thernal-sensing units in the cushion is achieved.The MFC-based soft-ware is developed to realize communcation with the hardware acquisition circuit,display of resisitance value and temperature value of the thermal sensing units,the temperature distribution image,and data storage and data inquiry.5.Experiments of the IRA-based hardwarte circuit and flexible thermal senasing cushion system are carried out.The performances of the IRMA are verified with the IRMA-based hardware circuit experiments.Simultaneously.experiments including cup,human hand and sitting posture sensing experiments are conducted with the IRMA-based flexible thermal sensor cushion system.Experiment results show that temperature distribution detection can be realized with designed thermal sensing cushion system.