| During operating mechanization of field management, a problem often encountered is the difficulty in traveling between the lines crew, often pressing seedlings, injury the seedling, affecting the work efficiency and quality of units. Especially operating twice a year, and the practice areas of intercropping, crop sowing due Previous Crops neat line of business is not enough, a subsequent set of multicast or very difficult for the follow-up field management and operations, it has become an obstacle to promote crop production and full mechanization. The traditional method is the use of paddle device, auxiliary unit building plot in the field or planting. However, due to the soil is relatively wet, the grooves which drew by paddle devices is wide and fuzzy, illegible, affecting the traveling linear of the unit, and prone bringing accumulated error. In order to change this situation, field operation unit laser guidance system is designed by learning paddle's working principle and laser emission-acceptance technology. With the help of this system, drivers can improve their driving ability.Laser guiding system for field machinery consists of laser systems and laser receiving system composed of two parts, the laser transmitter and laser light modulation circuit launching system is installed at both ends of the block, located in front of a moving unit, by the laser receiver and signal processing circuit of the laser receiving system, is fixed in front of the tractor cab. Its working principle is that the invisible laser which is produced by the laser system is accepted by laser acceptance system in the tractor. The receiver position is pointed out by LED, drivers can adjust steering wheel on time by the judgment of unit's direction offset. To improve the laser transmitter and receiver interference immunity and emission wavelength of 850nm laser is invisible infrared laser, and emission frequency modulation is 38 kHz. Meanwhile, in order to ensure a reliable receiver, laser transmitter uses lamp cap which transmits light like'—', even if the tractor up and down the field there would not affect the reception of laser signals.To verify the performance of the laser guiding system for field machinery, carrying on road test. The test divided into 3 groups, were independent traveling visual target in front, configuration paddle device traveling along the curb edge and traveling by the indicator using of laser guiding system, each experiment was repeated 3 times, the stroke is 50 m, test the travel offset units every 2 m, calculating the average of the 3 times and distribution. Selected infrared laser transmitter which the wavelength is 850 nm, the transmit power is 30 mW, the DC Voltage is 4.5 ~ 5.0 V, the current is less than 10 mA, the effective receiving distance of the laser is greater than 150 m. Test results: when not using the paddle device and laser guiding system, the maximum driving offset of the unit is 29 cm, the minimum offset is 1 cm, the average offset is 14.1 cm, the variance is 0.34; When using the paddle device: the maximum driving offset of the unit is 25 cm, the minimum offset is 0 cm, the average offset is 5.94 cm, the variance is 0.13; When using the laser guiding system: the maximum driving offset of the unit is 13 cm, the minimum offset is 0 cm, the average offset is 4.5 cm, the variance is 0.09. Under the conditions of the laser guiding system, the maximum driving offset of the unit, the minimum offset and the average offset, which were less than or equal the first two groups to test, showing that the role of the laser guiding system is effective.The laser guiding system is simple, easy to use and low cost. Using the system, the unit has no accumulation of errors when driving in the field, improved the driving linear of the unit, easy to carry out follow-up field operations, for the implementation of full mechanization has created good conditions. |
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