Study of H_* Control for 4WD Tractor-Implement Systems

本课题的研究目标是拖拉机机具系统的鲁棒控制器设计。研究工作分为四个方面：(1)包括系统内部旋转部件在内的拖拉机-农机具系统（TIS）野外作业条件下的数学模型的建立。(2)机耕机系统的田间试验及分析；(3)机耕机系统的参数辨识实验室试验；(4)机耕机系统的鲁棒控制器设计分析。(1)耕作作业下拖拉机-机具系统的动力特性拖拉机-机具系统一般在耕作作业下的重载工况下工作。在不同条件下进行了拖拉机系统耕作作业的田间试验。通过对这些数据的分析，建立了TIS在野外工作条件下的数学模型。该模型既包括内部旋转运动，也包括平移运动，代表了系统的反馈控制特性。(2)拖拉机-履带系统参数辨识为了明确TIS的整体行为，必须了解这两个参数。然后我们执行参数识别测试。其中一个参数是一对时间常数，表示系统的转矩-燃料关系和动力学。另一个是发动机传动系统的粘滞系数。提出了一种非线性RSM方法来辨识这些参数。(3)牵引机系统鲁棒控制器设计分析针对牵引机系统的非线性，提出了一种由H_*00鲁棒控制组成的控制器设计方法。由于农机具系统在耕作作业中受转矩扰动的影响较大，轮胎转速控制的稳定性在耕作作业中至关重要。首先，将混合灵敏度鲁棒控制方法应用于TIS，得到了H_*控制器集；其次，采用所提出的H_*控制器代替机械调速器，设计了TIS的反馈控制。该系统的动态特性得到了很大的改善。少

The objective of this research work is the robust controller design for tractor-implement system. The research work is divided into four categories (1) Formulation of mathematical model of tractor-implement system (TIS) under field operation condition including internal rotating parts of the system. (2) A field experiment with a tractor-implement system tinier tillage operation and its analysis, (3) A parameter identifiction laboratory test with the tractor-implement system, and (4) Robust controller design analysis with the tractor-implement systeim.(1) Dynamical characteristics of the tractor-implement system under tillage operationsGenerally a tractor-implement system works in heavy-duty conditions under tillage operations. We executed the field experiments for tillage operations with the tractor-impliment system under various conditions. Analyzing these data, we formulated a mathematical model for the TIS under field operating conditions. The model includes both internal rotational … More and translational motions and represents the feedback control characteristics of the system.(2) Parameter identification of the tractcr-implement systemFor the clarification of the TIS overall behaviors, the knowledge of two parameters is inevitable. We then execute the parameter identification test. One of the parameter is a pair of time constant that represents the torque-fuel relationship and dynamics of the system. The other is the viscous coefficient of the engine-transmission system. A nonlinear RSM method was introduced to identify these parameters.(3) Robust controller design analysis with the tractor-implement systemTalking account of the nonlinearity of the tractor-implement system(TIS), we propose a controller design method which consists of H_*00 robust control. As the tractor-implement system under tillage operation is heavily influenced by the torque disturbances, the stability of tire speed control is essentially important in tillage operations. First, we applied the Mixed-Sensitivity approach of the robust control system for the TIS and obtained the set of H_* controller Second, we designed the feedback control of the TIS using the proposed H_* controller instead of the mechanical govemor. The dynamic characteristics of the TIS are greatly improved. Less