| The paddy direct-seeding machine with lower labour and cost has a great future in our country. For the purpose of winning a greater advantage on economic and practical index, on the premise of satisfying agricultural need, developing a combined direct-seeding machine for multiple suited power, various work condition and sustainable development seems to have an insistent demand. The thesis originates from one of the key process of the research item called the little and intensive paddy-seeding technical research.The thesis applies Virtual Technology to the paddy field trial and optimal designing of the existing chassis:(1) Aiming at the Traction Characteristic Test on the existing chassis prototype, based on Virtual Instrument Technology and Sensor Technology, the thesis realizes a simple and applied testing system. From the hardware aspect, the system can watch status of the field by sensors, DAQ card and laptop PC. From the software aspect, the system can achieve sampling, analysis, display, storage and alarm modularized by LabVIEW, on-line watching & controlling and off-line analysis. The field trial confirms that the testing system is credible and reliable, and the sampling data have a satisfying precision at the speed of range from 0 to 0.5 meters per second.(2) By means of further analysis of the recorded data of the drawing signal and rotated speed signal. It indicates: Only when direct-seeding machine works at third speed and is loaded with earthbags having a 100 kilograms weight, the Unit has a better dynamic and economic performance. The ultimate load of the chassis is 250 kilograms.(3) The paddy field trial indicates: the weight of chassis affects the performance of direct-seeding machine, while the weights increasing, steering wheels sink badly and its rolling resistance has a sharp augmentation; the material and shape of the Floaty board have a great influence on the drawing performance, choosing a low friction material for Floaty board machining, and optimizing the shape with assistant fitting for slop-film lubricating completely, these means can reduce the friction between paddy field and Floaty board.(4) Aiming at the optimal designing of the chassis, based on Virtual Prototyping, the thesis constructs a Virtual test platform by ADAMS/View module, including the following steps, such as parameterized and geometrical modeling, inflicting restriction and outside force. Two measurement values are considered the Primary Index, there are moment inflicted on the driving wheel, restriction force between tractor and chassis, slipping rate on the driving wheel. Several parameters influencing on pass performance while the chassis running in the paddy field are considered the Design Variable, including mass center, wheelbase, steering-wheel tread, steering-wheel breadth and so on, which are carried on Design Study respectively. Then putting forward a set of the most appropriate Design Variable as follows: 1.8meter for wheelbase, 0.1 meter offset above the steering shaft, 1.5meter for steering wheel tread, 0.15 meter for steering wheel breadth. Modifying the prototype model using above-mentioned parameters, changing the mass of Floaty-board and doing virtual trial, it do realize simulative load and find a appropriate load of 150 kilogram at the Primary third speed. |
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