The Research And Application Of RLS Adaptive Filtering Algorithm In Width-height Detecting System

With the rapid development of China's national economy and society, the transportation industry plays an increasingly significant role. However, the problem about vehicle overload has become increasingly prominent with the rapid development of transportation industry. In the governance of oversized vehicles, it need to measure geometry size (including length, width and height of vehicle) of vehicle accurately, and there is noise in the process of measurements. This paper uses laser sensors on the vehicle's width and height detection, and use the RLS adaptive filtering algorithm to filter out the statistical characteristics of random noise. It can according to changes in the environment, and requires not priori knowledge of the statistical properties of the input signal and noise, gradually estimate the required statistical properties, and constantly changing its weight to achieve the function of the filter. In the software implementation, the M-file eventually be converted to a COM component by the Matlab COM Builder technology in matlab6.5 for the application calls for width-height detection system. It implements the mixed programming between VB and Matlab.The main contents of this paper are shown as follows:(1) By measuring and analysising the data of the width-height detection system, we conclude that the measurement data contains statistical characteristics of random noise.(2) Through the study about the structure and principle of the adaptive filter, we found that the adaptive algorithm can remove noises effectively;(3) LMS adaptive algorithm and RLS adaptive algorithm are compared. We studied the filtering performance between the two algorithms by matlab simulation. By contrasting, we choose the relatively superior RLS adaptive filtering algorithm used in the width-height detection system.(4) Matlab COM Builder function of Matlab6.5 has been studied. By the function module,the M-file is converted for COM components and registered to the target computer,then the width-height detection program based on VB language realize the adaptive filter function by calling the component implementation.(5) By the waveform analysis generated by simulation of Matlab and a large amount of measured data, proved that the noise interference in measurement data can be effectively restrained by RLS adaptive filtering algorithm.Therefore,the RLS adaptive filtering algorithm can improve the measurement precision and the design is effective and practical.(6) The summary and prospect of this research was made.It analysis of some problems existing in the width-height detection system, and points out its future.One of the major innovations of the recursive least squares (RLS) algorithm is applied to the width and height detection system for data processing; and the application of the software that will convert the file to a COM component M way, the successful realization of VB language call Matlab functions of the algorithm.