Research On Key Technology And Feature Extraction Method Of Saplings For Tending & Clearing Machine

At present, China forestry acreage and plantation acreage increase rapidly. With the continuous improvement of forestry workers’ income, the need for mechanized forestry practice become urgent. This research relies on public welfare project:research on key technology of tending and clearing equipment for plantation (201104007-3), the equipment mainly contains three parts:Mechanical body, hydraulic drive and feature extraction of working target. In the present paper, contents are orgnised focusing on this tending & clearing machine and the main reaserch contents and methods are as follows:1. Structure design and experiment of tending & clearing machine. Based on careful study of development of existing similar products at home and abroad, analysis the demand for platation usage, select disc working device structure as domestic mechine. Design the working device with the guide of traditional machine design theory and complete the prototype finally.2. Design and improvement of hydraulic system. During experiments of the project, hydraulic shock problems are founded, to solve these problems, a combination of theory and simulation methods are used to determine the hydraulic impact. On this basis, combining the needs of environmental protection, and energy conservation, an accumulator brake energy regeneration system is presented, and its optimized accumulator parameters are being obtained by using simulation method. The charge capacity is 1.2L, and its relevant charging pressure is 7MPa, a better energy regeneration effect can be obtained in this situation, in which can save 1775J in each stoping process.3. Study on the feature extaction method of reserved saplings. In actual prototype experiment, we found that operators need to on the one hand drive chassis between the trees lines and rows, on the other hand to operate the working device swing around the forest doing clearing operations, and in order to prevent accidental cut young trees, the driver need to carefully observe the surrounding environment. Such workflow increases the driver’s psychological pressure greatly, resulting in fatigue, thus reduces working efficiency. To solve this problem, a two-dimension laser scanner is used to scan and measure the work scene, by using scan data filtering, segmentation, feature extraction and classification methods to achieve recognition of saplings in the work scene, thus offer a theoretical basis to the establishment of intelligent control system.Through the above study, culminating in the following results:1. Design, manufacture new work equipment prototype for clearing & Tending.2. An improved Gaussian filtering algorithm is proposed particularly used for the two-dimension laser scan data processing.3. A differential algorithm using dynamic threshold is proposed to extract arc like data from 2D laser scan data.4. A set of saplings characteristics extraction method is proposed for 2D laser scanning based on tangent transform.Actual test proved clearing & tending device designed to work with good brush clearing effects, and the proposed filtering, extraction algorithm can extract saplings of small-scale from 2D laser scan data, and the proposed two features of saplings with 2D laser scan data have good recognition results.