Design Of Automatic Calibration System For The Car Pressure Sensor

Piezoresistive pressure sensor was widely used in the car and itsperformance was directly related to the overall performance and security of the car.But now the calibration system at home and abroad for the car pressure sensors haddisadvantages of low degree of automation, low accuracy and high cost. In responseto these problems, a car pressure sensor calibration system based on the software ofLabVIEW was designed, which could accurately calibrate car pressure sensor.Themain contents of this article include:Firstly, in order to understand why piezoresistive pressure sensor need to becalibrated, the article fully researched the structure principle and temperaturecharacteristic of piezoresistive pressure sensor; in addition, the article fullyresearched the method of calibrating piezoresistive pressure sensor and compareddifferent methods for their advantages and disadvantages.Secondly, design the hardware part of the calibration system, the hardware partof the calibration system included the mechanical structure part, gas path part, circuitpart. The design of mechanical structure part was mainly the design of bench andfixture, the design of the circuit part included the design of digital pressure sensor,data acquisition module, pressure control module, temperature control module.Thirdly, design the software part of the calibration system, the first step todesign the software was to analyze the demand of the software so as to design thesoftware. Use LabVIEW as the software language which had the characteristics ofshort development cycle and strong application reusability, the software used theway of modular design and it mainly included data acquisition module, pressurecontrol module, temperature control module, data analysis module.Fourthly, realize the calibration process and calibration algorithm, thecalibration process included calibration in advance and formal calibration.Fifthly, experiment with the sensor provided by manufacturer and analyze theresults of the experiment. Evaluation of repeatability and accuracy were marched onthe testing results, which was in accordance with the guide to dedicated detection equipment evaluation method JBT10633-2006. By calculation, the equipmentmeasurement capability indices were both more than2.0, which met the requirementsof new equipment acceptance.