Abstract:  In the field operation of the planter in the clean wheat area of the whole straw stubble field, the quality of straw mulching cannot be guaranteed due to the mismatch between the straw delivery rate and the speed of the uniform scatters device, resulting in problems such as low seedling emergence rate and poor seedling uniformity. Aiming to solve this problem, a set of strawspreading automatic control systems was designed. The system used STM32 singlechip microcomputer as the main control unit, used the phase difference torque detection device to collect the torque of the cutter roller shaft, and realized the adaptive adjustment of the speed of uniform scatters device through the indirect detection of the straw delivery rate. In order to verify the effect of the system, the cutter roller shaft spined at a top speed of 2 200 r/min, and the tractor was running at five common speeds, which were 0.9 m/s, 1.0 m/s, 1.1 m/s, 1.2 m/s, 1.3 m/s, respectively. A comparative test was carried out with or without the automatic control system of straw scattering and covering. In this experiment, without an automatic control system, the uniform scatters device rotated at 800 r/min. In contrast, the rotation speed of the uniform scatters device was automatically adjusted with the system, and the adjustment range was 600-1 200 r/min. The test results indicated that, in the same working conditions, after using the automatic control system for straw scattering and covering, the unevenness of straw spreading can be maintained below 15%, which improves the operational performance of the machine.

Key words: straw covering quality, delivery rate, speed of uniform scatters device, dynamic matching

摘要： 在全秸硬茬地小麦洁区播种机田间作业过程中，常因秸秆拾输量和抛撒转速不匹配，而无法保证覆秸质量，造成出苗率低、出苗均匀性差等问题。针对这一问题，设计一套秸秆撒覆自动调控系统，该系统以STM32单片机作为主控单元，利用相位差式扭矩检测装置采集刀辊轴扭矩，通过对拾输量的间接检测实现抛撒转速的自适应调节。为验证系统效果，以常用的5个拖拉机作业速度作为调节量度，分别为0.9 m/s、1.0 m/s、1.1 m/s、1.2 m/s、1.3 m/s，同一速度下分别进行有、无秸秆撒覆自动调控系统对比试验；刀辊轴始终以最大转速2 200 r/min进行作业；无调控系统时，抛撒转速保持设定值800 r/min；有调控系统时，抛撒转速自动调节，调节范围为600~1 200 r/min。试验结果表明，在相同工况下，使用秸秆撒覆自动调控系统后，能够将秸秆抛撒不均匀度始终维持在15%以下，提高了机具作业性能。

关键词: 覆秸质量, 拾输量, 抛撒转速, 动态匹配