轮式拖拉机是我国农业生产的主要机械设备，具有牵引力强，操作简单及维修方便等优点，但由于自身悬架性能较差及运行路况恶劣的原因，使得驾驶员在驾驶过程中长期承受低频高强度振动，严重损害驾驶员身心健康，降低工作效率。本文研究内容主要分两部分：拖拉机行驶路面不平度信息获取和座椅悬架半主动控制方法的研究。准确获取行驶路面信息是进一步改善轮式拖拉机减振性能的基础，本文采用双目立体视觉技术，通过获取道路二维图像实现对三维路面信息的重构，准确获取路面不平度信息；提出一种新型轮式拖拉机座椅悬架半主动控制方法，来改善拖拉机座椅的减振性能。本文的研究对于提高拖拉机行驶稳定性、驾驶员乘坐舒适性具有重要现实意义。具体研究内容如下：

（1）利用双目机器立体视觉技术，对轮式拖拉机行驶过程中路面环境进行感知，对双目立体视觉的原理及相关技术，ZED双目相机的标定、采集图像预处理、立体匹配、恢复三维信息等技术作了详细研究，搭建相机实验平台，双目相机标定平均误差在0.24像素，实验恢复三维信息与实际相差在2.95%以内，说明双目机器立体视觉在感知轮式拖拉机行驶环境方面的准确性，可行性。

（2）根据获得的三维环境数据，建立数学高程地形图。并利用邻域分析法分析高程地形图，提取地形坡度、起伏度、高程等地形因子的信息，在此基础上，进行拖拉机在100m标准路面上行驶路况信息的获取实验，提取出轮式拖拉机行驶过程中的路面不平度曲线，为轮式拖拉机整体和座椅的振动特性分析提供路面激励。

（3）提出一种新型带犁具轮式拖拉机系统的动力学模型并建立动力学微分方程组。该模型充分模拟了拖拉机带犁具作业时工况，以CF700型轮式拖拉机为研讨对象，以获取的路面不平度信息为激励，利用MATLAB软件求解带农具轮式拖拉机系统的动力学微分方程组，仿真轮式拖拉机系统在100m实验路面上的振动特性。得到被动座椅、驾驶室和车身的加速度、速度信息，分析得出被动座椅悬架的减振效果欠佳。

（4）提出一种新型轮式拖拉机座椅悬架的半主动控制方法，分为并联刚度开关切换策略和磁流变阻尼器天棚控制策略两部分。设计并联刚度开关系统并建立数学模型。研究磁流变阻尼器特性，对比不同的半主动控制方法优缺点，选用自适应天棚阻尼控制算法，对座椅悬架整体及刚度控制系统结构进行设计，通过硬件选型，制作出座椅实物，完成座椅悬架控制平台搭建，利用LABVIEW编写了座椅控制程序。通过在路面激励下的实验结果表明位移响应相对定刚度系统平均降低了22.5%，垂向加速度的整体水平降低了26.1%，验证了本文提出的座椅悬架半主动控制策略的有效性。

本课题的研究，对于准确检测轮式拖拉机行驶过程路面不平度信息，促进轮式拖拉机座椅悬架半主动控制研究，提高轮式拖拉机的乘坐舒适性具有重要的理论意义和实用价值。

ABSTRACT

The wheeled tractor is the main mechanical equipment of agricultural production in China, which has the advantages of strong traction, simple operation and convenient maintenance. However, due to the poor performance of its suspension and poor road conditions, the driver suffers from low-frequency rigid vibration for a long time in the driving process, which seriously damages the physical and mental health of the driver and reduces the working efficiency. The research content of this paper is mainly divided into two parts: the information acquisition of tractor road roughness and the research of semi-active control method of seat suspension. Accurate acquisition of road information is the basis of further improving the damping performance of wheeled tractors. In this paper, binocular stereo vision technology is used to reconstruct the three-dimensional road information and accurately obtain the road roughness information by acquiring the two-dimensional road image. A new semi-active control method of wheeled tractors is proposed to improve the damping performance of tractor seats It is of great significance to improve the driving stability of the tractor and the riding comfort of the driver. The specific research contents are as follows:

(1) By using the binocular machine stereo vision technology, the road environment during the driving process of the wheeled tractor is sensed, the principle and related technology of binocular stereo vision, the calibration of zed binocular camera, image pre-processing, stereo matching and 3D information recovery are studied in detail, and the camera experiment platform is built. The average calibration error of binocular camera is 0.24 pixel, and the experiment recovery is carried out The difference between the three-dimensional information and the reality is less than 2.95%, which shows the accuracy and feasibility of binocular machine stereo vision in perceiving the driving environment of wheeled tractor.

(2) According to the obtained three-dimensional environment data, the mathematical elevation topographic map is established. Based on the analysis of elevation topographic map by neighborhood analysis method, the information of terrain factors such as terrain slope, fluctuation and elevation is extracted. On this basis, the experiment of obtaining the road condition information of tractor on 100m standard road is carried out, and the road roughness curve during the driving process of the wheeled tractor is extracted, which provides the road excitation for the vibration characteristics analysis of the whole wheeled tractor and the seat.

(3) In this paper, a dynamic model of a new type of tractor with plough wheel is proposed and the differential equations are established. The model fully simulates the working condition of tractor with plow. Taking the cf700 wheeled tractor as the research object and the road roughness information obtained as the excitation, the dynamic differential equations of the wheeled tractor system with agricultural tools are solved by MATLAB software, and the vibration characteristics of the wheeled tractor system on the 100m experimental road are simulated. The acceleration and speed information of passive seat, cab and body are obtained, and the analysis shows that the damping effect of passive seat suspension is not good.

(4) A new semi-active control method of wheel tractor seat suspension is proposed, which is divided into two parts: parallel stiffness switch strategy and magnetorheological damper ceiling control strategy. The parallel stiffness switch system is designed and its mathematical model is established. Study the characteristics of MR damper, compare the advantages and disadvantages of different semi-active control methods, select the adaptive ceiling damping control algorithm, design the overall and stiffness control system structure of the seat suspension, through the hardware selection, make the physical seats, complete the construction of the seat suspension control platform, and use LabVIEW to write the seat control program. The experimental results under road excitation show that the displacement response is reduced by 22.5% on average compared with the constant stiffness system, and the overall level of vertical acceleration is reduced by 26.1%, which verifies the effectiveness of the semi-active control strategy of the seat suspension proposed in this paper.

The research of this subject has important theoretical significance and practical value for the accurate detection of the road roughness information, the promotion of semi-active control of the wheel tractor seat suspension, and the improvement of the ride comfort of the wheel tractor.