Research Of Log Maximum Inscribed Sircle Searching System

Since enormous waste of timber resources is the main reason for the development of forestry in China, logs centering technology is one of the important ways to improve the comprehensive utilization of timber. Along with the development of social economy has been increasing rapidly, there is an important significance for carrying out the centering research to enhance the comprehensive utilization of timber, reduce the waste of resources, relieve the strain on the timber resources and promote sustainable development of forestry.Logs digital centering technology is the technology that combined with advanced scanning technology and mathematical theory to depict logs digital silhouette and achieve logs centering. Compared with the traditional artificial centering and mechanical centering, it is not only had higher centering accuracy and speed of centering, it also can save the labor. To research centering optimization algorithm and detection method, the maximum inscribed circle search system research based on the traditional discrete centering theory is proposed, which extends a theoretical basis for later logs digital centering technology.Firstly, the concept of logs digital centering technology was expounded, then introduced several commonly methods which is used to determine the maximum inscribed circle logs section and analyzed their advantages and disadvantages respectively. The principle of using ultrasonic sensors to detect logs the outline data is introduced briefly. On the basis of several commonly used methods, this paper proposed a new algorithm of solving logs section maximum inscribed circle and introduced the basic idea of this method, the mathematical model, the experimental steps in detail.Secondly, describe the reconstruction method of log discrete 3-D profile briefly. Introduce least square cylinder method which is the common method for determining the log maximum inscribed cylinder. Discuss in detail the optimization algorithm to search for log maximum inscribed cylinder in this study, main steps are as follows:determining the direction vector of log central axis, determining the spatial location of log central axis and determining radius of the maximum inscribed cylinder.Then, study the whole experimental system, including the design of system general structure, Select the test equipments accurately based on system requirements, accomplish the design for program flow chart and hardware circuit diagram of the data acquisition and control system, set the human-computer interaction interface of touch screen and the communication between touch screen and the PLC, analyze the advantage of MATLAB as centering software, and give its programming interface.Finally, build a experimental platform of log maximum inscribed circle searching system, detect log profile data and calculate the log cross section maximum inscribed circle and log maximum inscribed cylinder based on the program software carried out by the optimization algorithm of this paper. Compare the digital centering results with CAD mapping results and artificial calculation results. Take the variance of calculated maximum inscribed circles as criterion, compare and analyze the accuracy of the commonly used wood section maximum inscribed circle detection algorithm to verify the accuracy, reliability, high precision of section centering algorithm put forward by this paper. Compare the log maximum inscribed cylinder determined by program software with artificial calculation to verify the correctness of the algorithm for cylinder and the reliability of the whole system.