ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

In the operation of grain combine harvester, the height control of header is particularly important. Effective header height control helps to improve the stability of feeding amount and reduce the working load fluctuation of each link of the whole machine. A kind of header height control strategy based on robust feedback linearization was introduced, which made the header follow the ground fluctuation to adjust the pitch control, so as to achieve the purpose of consistent stubble height. Firstly, the mathematical model of the system was established based on the analysis of the structure and dynamics of the header, and the approximate condition of sinusoidal angle reduction was selected to linearize the multi-variable complex nonlinear system into a typical nonlinear system. The traditional feedback linearization control was analyzed, and the controllable affine model building method was studied. The reason that it lacked of robustness due to its high dependence on the identification accuracy of the system was obtained. Furthermore, based on the integrated robust optimal design (IROD) controller, the robust feedback linearization (RFL) was proposed, which stabilized the system by constructing the sensitivity equation and selecting the gain;furthermore, the robust feedback linearization was proposed according to the current parameters of hydraulic output, the controller was designed for the output of robust feedback linearization control system. In the contrast simulation experiment, the traditional PID control was compared with the proposed robust feedback linearization control. The height error under the robust feedback linearization control was smaller than that of the traditional PID control under the conditions of different driving speeds, sinusoidal amplitude and terrain period;and the robust feedback linearization was realized under the measured conditions of three different driving speeds on rolling ground. Therefore, compared with the traditional PID control, the robust feedback linearization controller had higher steady-state accuracy and improved the consistency of stubble.