基于积分分离式PID控制的耕深调节系统研究

On Auto-Control of Tillage Depth Based on Integral Separation PID Control Algorithm

耕作过程中保持耕深稳定是提高耕作质量的重要措施之一.以小型耕耘机的后悬挂旋耕部件为研究对象,提出了一种基于积分分离式PID控制的耕深自动测量和调节的系统,采用双倾角传感器检测耕深,消除了田块自身与绝对水平面倾角的误差影响,通过在误差信号的处理中使用积分分离式PID控制算法,利用Simulink中的SimHydraulic模块对耕深控制系统进行动态仿真研究,与未加入PID控制算法时的仿真结果进行比较,发现几乎消除了系统的耕深超调现象.同时,将响应时间由4.0s左右缩短到1.4s左右,使耕深控制系统的动态响应达到较好的效果.田间试验结果表明,当耕深设定为10cm和16cm时,实测耕深稳定性变异系数分别为6.05%和3.54%,均低于10%,达到了农业机械作业标准所规定的旋耕作业农艺要求.

Keeping the stability of tillage depth is one of the important measure to improve the quality of cultivating in the process of cultivation.By studying the rear rotary component of a cultivator,this paper designed an electro-hydraulic tillage depth auto-control system,based on the integral separation PID control algorithm.To eliminate the error influence of the dip between the farmland and the absolute level,two dip sensors were used to detect the depth of tillage.the integral separation PID control algorithm was used to process the error signal.In order to study the dynamic response characteristics of the system,the dynamic simulation of the tillage control system is carried out by using Simhydraulic of Simulink.Compared with the simulation result of without PID control algorithm,the depth overshoot is almost disappeared.Also,the response time is reduced from 4.0s to about 1.4s,indicating that the dynamic response characteristics of the system reach a good level.The result of the field experiment showed that the variation of tillage depth stability coefficient is 6.05%and 3.54%when the depth is 10cm and 16cm,lower than 10%,reached the prescribed agronomic requirements of rotary tillage.