基于载荷特征预测的甘蔗联合收割机协调联动电液系统设计理论研究

The hydraulic system of the sugarcane harvester is a system with high power, multi-pumps and multi-actuators. the coordination and control between the various subsystems has a significant impact on improving the quality of the sugar cane harvest, preventing clogging of the conveying path, reducing energy consumption..Load of the hydraulic system are related with a variety of factors including the changes in terrain, depth of cut of the cutter, growing status of sugar cane and other logistics status,etc. Coordinated control of Electro-hydraulic System for Sugarcane Harvester based on load characteristic prediction will help improve the adaptability of the machine to ensure the continuous harvesting operations..The overall idea of the project is: to make hydraulic system absorbed power and engine power output adapted to each other through controlling the traveling speed to adapting the changes of load features; to make cut cane subsystem and conveying subsystem automatically tracking changes in the traveling speed of harvester in order to holding the ratio between the two subsystem under the ratio requirement through a new type mechanctronic servo speed control system. By using wavelet transform and support vector machines method, identificating extracting, integration clustering, optimizating the various characteristic parameters, to building intelligent control systems for online analysis and decision-making, and solving the difficulties of coodination and control regarding sugercane harvester system in the case of multiple parallel control parameters and a variety of constraints and conflicts. .Establish a mechanical - electronic - hydraulic system dynamics model of sugar cane harvesters, analyze operating characteristics of the system, find the key parameters affecting the operating characteristics of the system, then analyze the mechanism of interaction of these parameters. On this basis, propose a optimizing method of design.

甘蔗联合收割机的液压系统是一个多泵、多执行器、大功率的系统，基于甘蔗收割质量、防止输送通道堵塞、节能等要求，各子系统之间需要综合协调控制。由于系统工作载荷大小与地形的变化、刀盘的切深、物流的状态等多种因素有关，基于载荷特征预测的协调控制有利于提高机器的适应性，保证收割作业的连续进行。项目的总体构想是：通过控制收割机的行走速度以适应全局载荷的变化，使液压系统的吸收功率与发动机输出功率相适应；提出一种新型的机-电复合速度伺服控制系统，使砍蔗和喂送子系统能自动跟踪行走速度的变化，以保持两者间的速比要求。拟综合运用小波变换、支持向量机等方法，对各种特征参数进行识别、提取、聚类融合和优化，构建智能控制系统，实现在线智能分析与决策，解决大惯量、非线性、时变性、多约束复杂条件下，多泵多执行器的协调控制难题。构建该系统的动力学模型，研究其耦合运行特性、主要影响因素及影响规律，提出关键变量的优化设计方法。

甘蔗联合收割机的液压系统是一个多泵、多执行器、大功率的系统，基于载荷特征预测的优化设计和协调控制，有利于提高机器的适应性，保证甘蔗收割质量和作业的连续进行，提高节能效果。项目通过大量甘蔗机械收割试验采集各关键子系统的工作载荷和转速等信息，并基于雨流计数法构建了甘蔗收割机各关键子系统的载荷谱，获得了不同工况下载荷的均值、幅值、极值等分布和变化规律。提出一种新型的机-电复合速度伺服控制系统，通过动力学建模分析和试验验证其应用于甘蔗联合收割机的可行性并给出优化设计准则；研究了收割机液压负载敏感系统与载荷谱耦合运行的响应特性和节能性，揭示了影响系统性能的主要因素及影响规律；基于实测载荷建立刀盘轴、切断辊、风机等关键部件的疲劳寿命预测模型，并提出了零部件的优化设计方法。通过单因素试验和正交试验找到关键子系统运行参数对甘蔗收割质量的影响规律，并结合神经网络、粒子群优化算法、遗传算法、最小二乘支持向量机等智能预测算法实现对各液压执行器的协同优化控制。建立了甘蔗收割机工作模式的预测模型和砍蔗刀盘入土切深的预测模型，开发了一种基于数据实例和智能算法结合的甘蔗联合收割机关键部件运行参数决策支持系统，提出一种基于移动网络的甘蔗联合收割机远程监控系统设计及控制方法，实现对联合收割机工作参数进行远程实时监控，能对物流堵塞、刀盘入土切深、油温等进行预警，可以远程给出决策指导。为了验证本项目所提方法的有效性，将所研究的算法及系统在广西扶绥、武鸣、宁明、来宾等蔗区进行了应用性试验，优化效果明显。研究成果为丘陵地区甘蔗联合收割机的研究和优化设计提供了理论和应用指导，对同类多执行器作业机械的设计与优化硏究同样具有借鉴参考价值。