It is required to employ variable rate (VR) tillage because the soil is not uniform and immense spatial variability is available inside the agricultural fields. A conventional rotary tiller was instrumented to instantly vary the tillage intensity based on the tilled soil surface roughness measurement. The random roughness (RR) was estimated as the standard deviation of surface peaks and depressions which were measured using an infrared sensor. The tilling intensity was adjusted based on rising off and lowering down the tiller soil shield that was controlled by a hydraulic actuator. The soil shield could be adjusted from 0° to 80° in 20° increments with an average response time of 0.26 s. The field tests were performed in order to recognize whether the VR tiller can create predefined soil roughness which was assigned in three ranges of 0.5 ≤ RR₁ ≤ 1.5, 1.5 < RR₂ ≤ 2.5, and 2.5 < RR₃ ≤ 3.5 cm. As a reference, a pin-type profiler was utilized to measure the soil roughness created by the VR tiller. The results showed the soil shield tended to be closer when finer predefined roughness was requested. There were no significant differences in RR over the experimental subplots which received similar adjustments, verifying the tiller performance. The results also showed that different surface roughness could be statistically separated when they were created by the tiller at different travel speeds of 2.6, 3.5, and 4.8 km/h (p < 0.01), because the soil shield tends to be closer when the travel speed increases. The tiller developed in this study could perform VR tillage across the field with an overall success of 83.3%.

需要采用可变速率 (VR) 耕作，​​因为土壤不均匀并且农田内部存在巨大的空间可变性。使用传统的旋耕机根据耕作土壤表面粗糙度测量结果立即改变耕作强度。随机粗糙度 (RR) 被估计为使用红外传感器测量的表面峰和凹陷的标准偏差。耕作强度是根据由液压执行器控制的分蘖土盾的升降来调整的。土盾可以以 20° 的增量从 0° 调整到 80°，平均响应时间为 0.26 秒。进行现场测试是为了识别 VR 分蘖是否可以产生预定义的土壤粗糙度，该粗糙度被分配在三个范围内 0.5 ≤ RR₁ ≤ 1.5、1.5 < RR ₂ ≤ 2.5 和 2.5 < RR ₃ ≤ 3.5 厘米。作为参考，使用针式剖面仪测量 VR 分蘖产生的土壤粗糙度。结果表明，当要求更精细的预定义粗糙度时，土盾往往更接近。与接受类似调整的实验子地块相比，RR 没有显着差异，验证了分蘖性能。结果还表明，在 2.6、3.5 和 4.8 公里/小时（p < 0.01）的不同行驶速度下，由分蘖产生的不同表面粗糙度可以在统计上分开，因为在行驶时土盾往往更接近速度增加。本研究中开发的分蘖可以在整个田间进行 VR 耕作，总体成功率为 83.3%。