| Currently the international trend of pesticides spraying technology is precision medicine, the primary question and key technology of which is target detecting. Then build a matched up intelligent control system to achieve precisely target spraying. Based on analyzing the situation and developing trend of plant protection machinery and pesticide spraying technology, this paper listed and contrasted advantages and disadvantages, feasibility and economic applicability of several kinds of target detecting technologies, found out infrared detecting technology applied in plant target detecting have some characters, such as simple and feasible operation, low cost, high reliability and easy commercialized.Directed towards open fund project demand of modern agricultural equipment and technology key laboratory of Jiangsu province, then based on the analysis of infrared optical properties and working principle of detecting systems, the paper designed an infrared detecting system apply to plant targeting. The radiator of infrared detector was an infrared LED and receiver was an infrared photosensitive triode with a sensitivity adjustable photoelectric switch amplifier ahead. Besides, infrared optical lenses were installed before radiator and receiver to improve the efficiency of transmission and reception. Firstly took the simulate target as research object, then chose different convexes with different diameters and the focal lengths and combinations between LEDs with different power and different sensitivity of photoelectric switch amplifier, to make experiment according to different size of reflectors, light intensity and reflectance of the reflector, and got the best performance detector combination and capacity parameters. Secondly made real plants infrared detection experiments with the best detector selected before under the best working conditions. Then it analyzed the effects of the plant appearance, light intensity, temperature, humidity, walking speed and plant spaces to infrared detecting results. And it took a infrared targeting detection analysis with plants of trees, shrubs and grasses.Through the above work, it got the following conclusions:(1) Having a performance testing for several different specifications infrared detectors, the detection distance and detection width of the infrared detector, whose diameter is 36cm and focal length is 50cm (signed as"D36,F50"), had the best comprehensive effect, and the best working parameters got when infrared radiator with 0.42W and 10 grades sensitivity. Besides, the reflector edges sizes bigger and the surrounding light intensity stronger and the reflectance of reflector surface larger, the detection effect better.(2) In the actual growth environment, there had no significant effects on the plant infrared targeting results by temperature and humidity. The plants grow more densely, the stronger the reflection of infrared ray, the detection effect better. Meanwhile detection width change by the law that an increase followed a descent with detection distance increasing. Walking speed of detector had a linear correlation with the minimum distance of individual plant could be distinguished effectively. When plant spacing (hmin) was zero, the minimum speed limit theoretically(v) was 0.43m/s; And the plant space will affect the detector sensitivity with increasing and decreasing synchronously.(3) Although different species of plant had their unique characteristics in infrared detection results, they also had some similarities. Besides a improved universal law, the plants grow more densely, the stronger the reflection of infrared ray, detection width changed by the law that an increase followed a descent and there had a maximum value near mid-point, when the light intensity (R) increased, the most thick foliage of every kind plants could significantly increased in detection distance, and the other two differences, which had significant differences from other two in same group.The capacity of infrared detecting system and the law of affecting factors were quested, effect of affecting factors for detection results when doing infrared targeting detection with real plants were researched, and detections of different kinds of plants were done in this paper, all of which provided putting forward a optimization target program match up to the intellective target spraying control system practiced on real plants for a theoretical basis and technological base, and provided datum for the construction of classific plant infrared detection database, meanwhile had a theoretical contribution for industrialization of target spraying technology, improvement of agricultural ecological environment and achieve the high efficiency and low pollution agriculture operations. |
PDF Full Text Request