高地隙自走式喷雾机全工况滑转率控制方法研究

发布时间：2018-07-24 11:41

【摘要】：高地隙自走式喷雾机属于一种大型、高端农业装备,它能用于几乎所有农作物及经济作物,尤其是高秆作物的大面积、高效率和精准植保作业,从而大大减轻农民的劳动强度,最大程度地保护劳动者和明显提高经济效益。目前,国内的高地隙自走式喷雾机主要依赖高价进口,而国产喷雾机整机性能难以满足使用要求。驱动系统作为车辆底盘的主要组成部分之一,对喷雾机整机性能有重要影响。作为保证整机驱动系统性能发挥的重要手段,车轮滑转率控制系统直接影响到喷雾机的作业效率、行驶的稳定性和安全性等。因此,本文针对高地隙自走式喷雾机车轮滑转率控制相关技术和方法进行了深入研究,具体内容包括:(1)通过对比分析现有高地隙自走式喷雾机常用的6种防滑驱动方案的结构组成、适用范围及防滑控制优缺点,提出了2种分别适用于中小功率、大功率高地隙自走式喷雾机的全工况滑转率驱动控制系统方案。同时,根据功能需求设计了一种主动电比例防滑控制阀(ASC阀)及喷雾机底盘驱动系统液压原理图。基于流体力学相关理论,建立了基于边界条件的分流集流阀(即HIC阀)、电比例ASC阀的数学模型,并建立了基于HIC阀、ASC阀的4种喷雾机滑转率控制液压驱动系统数学模型。基于喷雾机驱动系统的Matlab/Simulink仿真模型,对HIC阀、ASC阀特性进行了仿真分析,并对上述4种方案防滑控制效果及防滑阀的能量损耗进行了仿真对比分析。(2)根据高地隙自走式喷雾机独特的结构及功能特点,建立了十五自由度整车动力学模型,包括车身的6个自由度、4个非簧载质量的垂向跳动自由度、4个车轮的转动自由度、1个车轮转向角自由度。该整车动力学模型主要由车身模型、车轮模块、转角计算模块、悬架系统模型、轮胎模型及驱动系统模型等组成,能充分反映车辆在各方向的动力学特性。同时,分别建立了大功率、中小功率喷雾机整车的Matlab/Simulink仿真模型,并进行了几种典型工况下的仿真分析及实车试验研究。(3)分析了喷雾机产生滑转的原因、滑转基本原理及防滑控制方法。针对实际中喷雾机车轮轮心速度不易直接获取的问题,制定了车轮打滑判断标准:直线行驶时采用相对滑转率来判断、转向行驶时采用相对转速比差来判断。针对喷雾机转向时车轮偏转角的获取问题,设计了喷雾机两轮及四轮转向系统方案,并建立了全液压转向系统数学模型。基于ASC阀电比例控制原理,建立了包含外部输入模块、整车动力学模块、转向系统模块、驱动系统模块及控制系统模块的喷雾机滑转率控制系统。分别制定了 PID控制、模糊控制策略,并利用Matlab/Simulink软件进行了防滑控制的仿真对比分析。针对ASC阀控制时存在节流损失的问题,本文提出了一种基于全工况的滑转率控制策略,可根据具体运行工况、能耗对比分析来决定ASC阀的启闭。(4)开发了防滑控制器,并基于硬件在环仿真技术,搭建了高地隙自走式喷雾机滑转率控制系统硬件在环仿真试验平台,进行了防滑控制相关的试验验证。
[Abstract]:The high gap self-propelled sprayer belongs to a large, high end agricultural equipment, which can be used for almost all crops and economic crops, especially high straw crops, high efficiency and precision planting, thus greatly reducing the labor intensity of farmers, protecting workers and improving economic benefits to the greatest extent. At present, the high land in China The self-propelled sprayer mainly depends on the high price import, and the performance of the domestic sprayer is difficult to meet the requirements. As one of the main components of the vehicle chassis, the driving system has an important influence on the performance of the whole machine. As an important means to ensure the performance of the whole drive system, the wheel slip rate control system has a direct impact on the system. The efficiency of the sprayer, stability and safety of the driving, and so on. Therefore, this paper studies the technology and methods of the rotation rate control of the high clearance self walking spray locomotive. The specific contents include: (1) through the comparison and analysis of the structure of the 6 kinds of anti-skid driving schemes commonly used in the existing high clearance self walking sprayer, the application model is applied. For the advantages and disadvantages of the control and anti skid control, 2 schemes are proposed for the sliding rate driving control system, which are suitable for small and medium power and high power high gap self walking sprayers. At the same time, a hydraulic principle diagram of the active proportional anti slip control valve (ASC valve) and the bottom disk drive system of the sprayer is designed according to the functional requirements. In theory, a mathematical model of the 4 type of ASC valve based on HIC valve and ASC valve is set up, based on the boundary condition, and the mathematical model of the 4 kinds of spray rate control hydraulic drive system based on the HIC valve and the ASC valve. The simulation analysis of the HIC valve and the ASC valve characteristics is carried out based on the Matlab/Simulink simulation model of the spray machine driving system, and the performance of the ASC valve is simulated and analyzed. The anti slip control effect of the 4 schemes and the energy loss of the antiskid valve are compared and analyzed. (2) based on the unique structure and function characteristics of the high clearance self walking sprayer, a fifteen degree of freedom vehicle dynamic model is set up, including 6 degrees of freedom of the body, the vertical runout freedom of 4 non spring loads, and the free rotation of the 4 wheels. The dynamic model of the vehicle is composed of the body model, the wheel module, the angle calculation module, the suspension system model, the tire model and the driving system model, which can fully reflect the dynamic characteristics of the vehicle in all directions. At the same time, the Matlab/Simul of the high power, small and medium power sprayer is built, respectively, Matlab/Simul. Ink simulation model, and the simulation analysis and real car test research under several typical working conditions. (3) analysis of the cause of the skidding of the sprayer, the basic principle and the anti slip control method. In view of the problem that the wheel wheel center speed of the spray locomotive is not easy to obtain directly, the judging standard of the wheel skidding is formulated. To judge the slip rate, the relative speed ratio difference is used to judge the steering. In view of the problem of getting the wheel deflection angle when the sprayer steering, the scheme of the two wheel and four wheel steering system of the sprayer is designed, and the mathematical model of the full hydraulic steering system is set up. Based on the principle of the ASC valve electric proportion control system, the external input module and the whole vehicle are set up. The dynamics module, the steering system module, the driving system module and the control system module of the sprayer slip rate control system. The PID control, the fuzzy control strategy are formulated respectively, and the anti skid control simulation of the control is carried out with the Matlab/Simulink software. In view of the problem of the throttle loss in the control of the ASC valve, a base is put forward in this paper. The sliding rate control strategy in all working conditions can determine the opening and closing of the ASC valve according to the specific operating conditions and energy consumption comparison and analysis. (4) the anti skid controller is developed. Based on the hardware in the loop simulation technology, the hardware in the skid rate control system of the high clearance self walking spray machine is set up in the loop simulation test platform, and the test of anti skid control is carried out. Certificate.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S491

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