基于土壤比阻的大功率拖拉机变权重力位综合控制研究

摘要

In order to adapt to the multivariate environment of soil condition,a control algorithm based on soil specific resistance for force-position mixed control was explored.By building fuzzy PID control strategy,soil specific resistance B was introduced to simulate soil environment,and Matlab was used to analyze the specific resistance of different soils.Based on the system overshoot,stability time and change of tillage depth,combined with practical experience,the relationship between weight coefficient and soil specific resistance was discussed,and the control algorithm of weight coefficient was designed by the relationship.The method was compared with the method with fixed coefficient of 0.5,and the field tests were carried out.The experimental results showed that the method of variable weight force-position mixed control using this control algorithm can take advantage of position adjustment in the soil with smaller resistance,so as to ensure the depth of tillage;in the soil with larger resistance,the advantages of force adjustment can be taken to ensure the performance of the engine.The method can realize the automatic judgment and setting of the weight coefficient in the area where the soil specific resistance changed greatly,and laied the foundation for the more accurate control of the system,which can also have implications for researchers in the field.%针对土壤条件变化较大的作业环境,基于土壤比阻的力位综合控制,探索了其权重系数的自动控制算法.通过构建模糊PID控制策略,并采用土壤比阻B模拟土壤环境,利用Matlab对不同土壤比阻进行分析,以系统超调量、稳定时间以及耕深变化为依据,建立了权重系数与土壤比阻之间的关系模型,得出了基于土壤比阻的权重系数自动控制算法.将采用该算法的变权重力位综合控制(以下简称“变权重方法”)与权重系数为0.5的控制方式进行田间试验并对比.结果表明,变权重方法在土壤比阻较小的区域可以保证耕深,发挥位调节的优势;在土壤比阻较大的区域可以确保发动机的性能,发挥力调节的优势.该方法在土壤比阻变化较大的区域可实现权重系数的自动判断与设定,为系统更精确化控制奠定了基础.