Design And Test Of The Hillside Tractor Body Automatic Leveling Control System

Automatic leveling system combined a variety of technology such as electronics, control,and hydraulic,achieved the Integrative Technique of Mechanics-electronics-hydraulics.Thethesis takes the miniature hillside tractor research prototype as the research object developedby Northwest A&f University and the body automatic leveling technology is applied to thehillside tractor, improving the automaticity of the hillside tractor, making the operation moreconvenient,the main research contents and conclusions are as follows:(1) The thesis proposed a hillside tractor body automatic leveling control systemscheme.The hillside tractor hydraulic leveling principle was analyzed; the mathematicalmodel of the hillside tractor body leveling process was obtained; a body automatic levelingscheme was proposed on the basis of it，then according to the requirements of bodyautomatic leveling scheme, designed a body automatic leveling device and analyzed itsrelated parameters; the function of each module of the control system was introduced,thescheme satisfied the requirement of practical work.(2) The thesis completed the circuit design of the automatic leveling controlsystem.With function of the realization of the automatic leveling control system as the mainline, respectively designed the obliquity signal collection circuit, the LCD display circuit,the serial communication circuit, the limit switch interface circuit and the wireless signalreceiving circuit; the working principle of each circuit in detail was introduced; finallydesigned the PCB board of the body automatic leveling control system.(3) The thesis completed the software design of the automatic leveling controlsystem.With the working process of the two processors as the main line, respectively designthe angle signal A/D conversion algorithm,the angle signal acquisition algorithm, the serialport communication algorithm, the angle signal filtering algorithm, the angle signal displayalgorithm and the body automatic leveling algorithm; the working principle and workingprocess of the each algorithm was introduced in detail; realized the algorithm in C language;set the leveling accuracy of the body tilt angle α is2°<α<2°.(4) The related experiments were carried out after the completion of the design of thebody automatic leveling control system. The filtering parameter and the hydraulic cylinderspeed were determined through the experiments; then verified the A/D conversion and the LCD display algorithmon on the Proteus emulator; the wireless remote control module andthe automatic leveling algorithm was verified in a laboratory environment; the relatedequipment were installed in the hillside tractor and outdoor experiment was carried out.Theexperiment shows that, under laboratory environment, the related circuits and algorithms ofthe body automatic leveling control system have high reliability, but in the outdoorenvironment, due to the influence of random noise produced by vehicle vibration,thefiltering effect of the filtering algorithm is not ideal, leading to the lower body automaticleveling accuracy,its value is only40%.