谷子精量排种控制系统的设计与试验

Design and Experiment of Millet Precision Metering Control System

针对现有气吸式谷子播种机播种量大、播种穴距不均匀、重播漏播严重等问题,设计了一种谷子精量排种的控制系统,并详细地阐述了系统的工作结构、工作原理、硬件选型设计及软件算法控制。系统通过安装在地轮上的旋转编码器输出脉冲信号给STM32单片机,计算出播种机前进速度并输出PWM信号控制排种器转速;同时,在排种器内部安装红外传感器检测单位时间内的落种数进行排种器重播漏播判定,当出现重播漏播现象后,STM32单片机通过改变PWM方波占空比进行无极调速电机调速从而调节气室内风压,达到控制精量排种的目的。台架试验结果表明:谷种穴距合格率为88.00%~90.67%,穴粒合格率88%~91.34%,漏播率为5.33%~7.33%,重播率为2.67%~4.67%,各项指标均符合谷子播种机质量标准和农业要求。

Aiming at the problems of the existing air suction millet planter with large seeding volume,uneven seeding hole spacing,serious replay missed seeding and users unable to timely,etc.,a control system for millet sperm metering was designed and elaborated in detail.The specific working principle of the system,hardware selection design and software algorithm control.The system uses the rotary encoder installed on the ground wheel to output pulse signals to the STM32 single-chip microcomputer to calculate the forward speed of the seeder and output the signal to control the speed of the seeder,and install an infrared sensor inside the seeder to detect the number of seeds per unit time.The seed metering device replay missed determination,when the replay missed phenomenon occurs,the STM32 single-chip microcomputer adjusts the speed of the stepless speed motor by changing the PWM square wave duty cycle to adjust the air pressure in the air chamber to achieve the purpose of controlling precise seeding.The bench test results show that the qualified rate of seed hole spacing is 88.00%-90.67%,the qualified rate of hole grain is 88%-91.34%,the rate of missed seeding is 5.33%-7.33%,and the replay rate is 2.67%-4.67%.The indicators are in line with the quality standards of millet planters and agricultural requirements.