Supersonic Distance Measurement Based On Correlation Approaches Of Pseudo Random Binary Sequences

Distance measurement plays an important role in such area as industry, agriculture, national defense and so on. Attention of Measurement technology with high efficient and high precision have been extensively-paid by experts of these area domestically and international. With excellent character of beam emission and direction when transmitting, supersonic is easy available, inexpensive, unrestricted by environment ,and less difficult when measuring. As a result, supersonic is widely used in a majority of area.Traditional adapted main principal of supersonic distance measurement is to compare the time difference between launched band and receipted band, and then distance measured can be obtained based on the relation of distance and time. The primary choice of hardware is various of series of single chips and the arithmetic of measurement is to gain come-and -go time through simple compare of signal, accordingly, this method is adapted in less demanding occasion. However, because of intrinsic disadvantage of single chips and relative simple of arithmetic, this measurement's precision is low and the effective distance is less. A lots of factors in environment also have influence on it. So precision improvement and disturb resistance enhancement has became the primary heading of development of technology of supersonic distance measurement.Pseudo random binary sequences are widely in communication and cryptology because of its nicer correlation performance. Among those sequences m sequences gain more applications. M sequence can be obtained both through hardware and through software. So its application in measurement and control became popular among research subjects.Digital signal process technology has close relation with Computer, Electron, Information and automatization . With the rapid development ofthose relative, especially change quickly of chip technology, recent 20s years saw the flying development of digital signal process, of it the most impartment is extensive practice of DSP chips. As a special digital signal process chip, DSP chips almost penetrate anywhere both in production and life of peoples to change the way of production and life. In some high-required areas, DSP chips has been main choice in measurement and control as substitute of single chips. Fewer price of those chips make it possible for more widely use ness of digital signal process in modern production and life.Theoretic base is as follows: Emission supersonic signal is driven by s sequences, and its correlation operation outcome with reflected band is the primary basis of access of time of emission and reflection, which become the academic foundation of those thesis. Another impactment factor is hardware platform of this arithmetic whose foundation is predominant digital signal process capability of DSP chips.Detailed method of distance measurement is analyzed in this thesis, characteristic of supersonic capability performance and its theory of measurement is set forth. Capability of m sequences and its self-correlation is illuminated. So the theory structure of supersonic distance measurement based on correlation approaches of pseudo random binary sequences. On the basis of it hardware and software is given in this thesis.