亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

Traditional precision rapeseed planters mostly use passive land wheel to drive seed metering device. The phenomenon of land wheel slippage is easy to occur under high-speed operation conditions. This phenomenon resulting in missing seeding and other more serious problems, which reduced the quality of precision seeding in high-speed operations. Besides, traditional precision rapeseed planters are difficult to achieve precise adjustment of seed spacing and seeding amount by manual gearbox. In allusion to the problems mentioned above, a speed-dependent control system of rapeseed precision seeding which used STM32 as MCU and realized real-time data interaction with the WeChat applet on the mobile phone through the Bluetooth module was proposed. Different from the traditional electric drive seeding control system, two speed measurement were used in this system, the land wheel encoder and BDS receiver were used to measure the forward speed of the tractor during low-speed and medium-high-speed operation respectively. When the system was working, MCU analyzed the data from each sensor and generated motor control commands to drive the closed-loop stepper motor to drive the rotation of the seed metering shaft, so as to realize the matching of seed metering shaft speed and tractor forward speed, and to realize the stepless seeding amount adjustment. Meanwhile, users could set parameters such as target seed spacing, ratio of transmission and land wheel diameter through the WeChat applet to apply to different seeders, and key parameters were obtained such as total seeding amount and seeding area. Crucial parameter calibration experiment showed that the critical negative pressure of adsorption seeds was 1477Pa, the critical speed of switching the speed measurement mode was 3.7km/h, speed measuring range was 1.44~12.77km/h and motor speed regulation frequency was 5Hz. The bench experiment results showed that the seeding quality of speed-dependent control system was better than seeding at constant speed, and seed spacing qualification index was higher than 87% when the speed range was 2.6~7.8km/h. The field experiment results showed that seeding error was less than 3.9% and seed spacing qualification index was no less than 84% at seeding speed ranged from 1.44km/h to 7.99km/h. The system met the requirements of rapeseed precision seeding and can provide a reference for the improvement of the structure of speed-dependent control system of precision rapeseed planters.