Research On Ultrasonic Technology Of High-precision Single Probe Ranging And Multi Probe Positioning

Ultrasonic ranging technology has many strong points,such as low cost,high performance,strongly anti electromagnetic interference ability,no effect on light and color of object,and other advantages,compared with other ranging technology.It was widely used in vehicle driving,liquid level and material position measurement,detection field,localization and obstacle avoidance for intelligent robots.The range of ultrasonic ranging module in common is generally short and the accuracy is not high.The localization algorithm for ultrasonic positioning system which widely used need to solve the nonlinear equations,its solution is complexity and its time of calculation is longer,this is not conducive to the real-time of the system.To solve these problems,the main contents of this thesis are as follows:(1)Have studied the ultrasonic propagation process in depth.A power ultrasonic driving circuit with the driving voltage of 100V is designed.In order to reduce the influence of high power drive on the time of the inertia of the probe,this thesis has a design to reduce the time of the inertial vibration of the probe;(2)Have designed and accomplished a ultrasonic signal receiving circuit,this circuit has some parts such as program control amplifier,bandpass filter,two stage amplifier,envelope detection,dual threshold comparator and so on.Through the WiFi Signal adjust the time reference between transmit and receive circuits.(3)Using the capture function of DSP successfully and accurately collected ultrasonic echo signal.I have completed launch program and receiving program based on C8051F020(launch circuit controller)and DSP2812(receiving circuit controller).Lab VIEW PC program is written,this program can show the moving track of the target.(4)A new,highly efficient and accurate positioning algorithm is proposed and the positioning principle and thought of the method are described in detail in this thesis.The feasibility of the algorithm is verified by experiments.(5)The accuracy of distance and the positioning measurement of the system is carried out in the indoor case.The cause of the error and the error of the system is analyzed in detail.The absolute error of distance measurement is less than 5 centimeters in the range of 10 meters.The relative error is less than 1%within 1 metres to 10 metres.The absolute error of positioning measurement for the XY direction is less than 5cm in the measurement range of the system.