基于发动机转速的拖拉机机组协同控制研究

Research on Cooperative Control of Tractor Based on Engine Speed

拖拉机进行犁耕作业时受到土壤特性、道路坡度等不确定因素的影响,故针对拖拉机在作业中外部干扰的复杂与多变性,提出一种发动机转速-耕深协同控制的方法。基于AMESim与Simulink建立了拖拉机纵向动力学模型,考虑犁耕作业时土壤特性变化下农具牵引阻力的变化,通过对档位、油门位置、犁具耕深的控制实现了机组的综合自动化控制,获得了良好的动力性。仿真结果表明:在土壤阻力增加较小时,牵引阻力增加,发动机转速将降低,此时油门位置将增加以避免换挡;土壤阻力增加较大且油门位置为最大时,作业机具将小幅提升以避免转速急剧掉落;极限情况下,拖拉机将降挡以避免发动机熄火。台架试验表明:所提出的控制方法可实现通过减小耕深而保证发动机稳定运转的效果。

Due to the influence of uncertain factors such as soil characteristics and road slope,a collaborative control method of engine speed and tillage depth is proposed to deal with the complexity and variability of external interference during tractor plowing.Based on AMESim and Simulink,the longitudinal dynamic model of tractor is established.Consid-ering the change of traction resistance of farm implements under the change of soil characteristics during ploughing,the comprehensive automatic control of the unit is realized through the control of gear,throttle position and plough depth,and good dynamic performance is obtained.The simulation results show that when the soil resistance increases,the traction re-sistance increases,the engine speed decreases,and the throttle position increases to avoid gear shifting;When the soil re-sistance increases greatly and the throttle position is the maximum,the work tool will be lifted slightly to prevent the speed from falling sharply;In extreme cases,the tractor will downshift to avoid engine stalling.The bench test shows that the proposed control method can ensure the stable operation of the engine by reducing the tillage depth.