Agricultural Machinery Based On GNSS Navigation Attitude Calibration Study

In the process of development of precision agriculture and intelligent agriculture, most of the domestic and foreign researchers are on the road flat under the environment of agricultural machinery automatic navigation of the experiment, the research of agricultural machinery navigation ultimate goal is to realize the navigation operations, in the field of agricultural machinery and agricultural machinery in the field operation process, the ground uneven lead to car body centre of gravity will be in a small range of space to do certain mechanical wave, bodywork tilt by pitching Angle and roll Angle. Generally speaking, the attitude Angle is usually in the range of 0 to 25 degrees. The tilt will directly affect the GNSS positioning accuracy. Usually GNSS antenna height distance is 3 m, roll Angle phi is 15 degrees, the receiver antenna positioning in the car body lateral 39 cm positioning error, if the roll Angle phi of 25 degrees, will create unacceptable in the horizontal coordinate positioning error. This error has already exceeded the requirements of the precision agriculture cm-level positioning accuracy, and the tilt error for large-scale farm sowing and harvest control precision of the navigation requirements is unacceptable and must be corrected.The subject of this study is on the basis of improved pure tracing model navigation algorithm upload attitude correction algorithm of the introduction of pavement under the environment of ups and downs of linear planning and path tracking control, first research analysis calculation of navigation and positioning principle and absolute positioning and differential positioning principle.Secondly on the basis of the navigation and positioning and analyzes the dual antenna heading attitude measuring principle and pose measurement principle of electronic compass, and then the posture calibration algorithm design and hardware and software design of agricultural machinery automatic navigation control, analyze the basic structureof the carriage, provide hardware platform for the research on the experiment; Analyze the mathematical model of the four-wheel electric vehicle research, provide a basis for the research of automatic navigation algorithms. An improved path tracking algorithm is proposed, and conducted on MTALAB simulation.Finally with electric cars, modified by field experiment, set on the upper machine controller is going to take driving route, automatic navigation experiments. GNSS satellite receiver real-time record farm machinery location, location of the record is model car actually walking paths. Transform the original conditions, repeatedly experiment, analysis of the experimental results, the analysis results show that the maximum error of automatic navigation to maintain within 12 cm. Joined the posture calibration experimental results verify the effectiveness of path tracking algorithm, verify the navigation control system is stable and reliable.