The Study And Design Of Laser-Controlled Land Leveling System

China is a large agricultural country, in order to develop the production scale of the agriculture; we must develop the land leveling technology. The higher flatness of the land, the more uniform by the watering and the fertilizing, it is good at emergence uniformity, it helps to improve crop yield and help the realization of agricultural mechanization. Laser controlled land leveling system is the most advanced and effective precise land leveling technology. After the operation, the ground can be achieved the accuracy of 1 ~ 2cm. However, the laser graders is expensive in abroad, and domestic laser leveling technology is still not perfect, these are hider the technology develop in china. Therefore, proposing and designing a laser-controlled land leveling system, which can used in China, has important practical significance and a high scientific value.(1)According to demands of the whole system, this paper proposed a system with single laser receiver and another system with two laser receivers to fitness the different widths of flat shovels, to solve the problem of the inclination because of the wide of the flat shovel.(2)Analyzed and compared the LASER used in land leveling system at home and abroad, this paper chose a homemade laser swinger system as laser transmitters to meet the operating precision in order to reduce costs.(3) Researched and designed a laser receiving device. Based on theoretical analysis, using spatial filtering, spectral filtering and circuit filtering deal with background noise in three steps, it can filter solar radiation and other background light on the impact of laser; Designed a 22×4 array of changes in pitch as the laser light battery receiver photoelectric sensors; Designed the signal processing circuit, it can change the light signal into a TTL level signal, and used PROTUES to complete the hardware emulation; Completed a peripheral circuit and software programming design of MCU, achieved a position error signal recognition and code output.(4) Researched and designed a laser controller. Analysis the distance impaction of the signal transmission, using the RS-485 bus to complete the two-MCU serial communication, realized the position signal transmission between the receiver and controller; Chose AT89C51 microcontroller as the controller microprocessor, used PROTUES to design external circuits, used KEIL C to write the programming, through the position error signal recognition, realized the real-time control with the moving direction and magnitude of the flat shovel.The laser controlled land leveling system can realize automatic land leveling, the precision can achieve around 1cm, the working area is 300m, working height range is 20.9cm, meet the requirements of design.