拖拉机组驾驶员持续疲劳状态腰椎加速损伤机理及其减损控制方法

The tractor driver exposed to vibration environment is extremely easy to fatigue. More than 80% of drivers suffer from lumbar disease due to the coupling effect of fatigue and vibration accelerating lumbar spine injury. This project takes the tractor driver as the research object, reveals the accelerated lumbar spine injury mechanism of tractor drivers, and research damage-mitigating control method of Lumbar Spine Damage. The main research contents are as follows: (1) The evolution law that the drivers’ lumbar physiological function increases with their fatigue degree is clarified based on vibration test of tractor unit and driver fatigue identification. (2) The cab-driver musculoskeletal biomechanical model will be established to analyze the effects of drivers’ fatigue and vibration intensity on the stress of lumbar joints and muscles. (3) To reveal the mechanism of lumbar spine injury of tractor drivers, the lumbar vertebra-pelvis-sacrum complex finite element model is established, and numerical calculation of lumbar spine injury is done based on the load boundary conditions of lumbar spine. (4) Finally, the tractor seat with three degrees of freedom is designed, and the matching relationship between vibration characteristics and suspension characteristic parameters is clarified based on the mechanism of lumbar spine injury of tractor drivers. The stiffness control strategy of electronically controlled air spring is determined, and bench test and field test are carried out to verify the effectiveness of seat suspension. The research content of the project provides theoretical and technical support for the protection of tractor drivers’ lumbar spine injury.

拖拉机驾驶员暴露振动环境中极易疲劳，疲劳和振动的耦合作用加速腰椎损伤，超过80%驾驶员腰部患有疾病。本项目以拖拉机驾驶员为研究对象，揭示驾驶员持续疲劳状态下腰椎加速损伤机理，开展拖拉机组驾驶员腰椎减损控制方法研究。主要研究内容：（1）开展拖拉机组振动测试与驾驶员疲劳程度辨识，阐明驾驶员腰部生理机能随疲劳程度增加的演化规律；（2）创建驾驶室-驾驶员肌肉骨骼生物力学模型，分析驾驶员疲劳程度和振动强度对腰椎关节和肌肉受力的影响；（3）创建腰椎-骨盆-骶骨复合体有限元模型，基于腰椎生物力学模型建立腰椎损伤数值模拟载荷边界条件，揭示驾驶员疲劳状态下腰椎加速损伤机理；（4）设计拖拉机三自由度座椅悬架结构，基于腰椎损伤机理阐明振动特性与悬架特性参数匹配关系，确定电控空气弹簧刚度控制策略，开展台架试验和田间试验验证座椅悬架有效性。项目研究内容为保护拖拉机驾驶员腰椎损伤提供理论依据和技术支撑。

本项目搭建了拖拉机驾驶员人机交互测试系统，运用三维运动捕捉、表面肌电等仪器设备，获取了驾驶员在不同坐姿和作业时间工况下，腰部肌肉激活程度、驾驶员脊柱姿态和主观疲劳感受等试验测试数据，创建了拖拉机驾驶室-驾驶员肌肉骨骼生物力学模型、腰椎-骨盆-骶骨复合体三维有限元模型。通过试验数据和数值计算系统的阐明拖拉机驾驶员坐姿、驾驶室振动特性等对腰椎关节受力和腰部肌肉激活程度的影响。项目发现驾驶舱倾斜导致驾驶员坐姿变化会显著增加驾驶员腰椎肌肉疲劳和腰椎关节剪切力。结果显示，（1）随着倾斜角度增加驾驶员全身最大肌肉激活程度和凸侧竖脊肌肌肉激活程度不断增加，且驾驶室振动显著增加肌肉激活程度。（2）随着拖拉机侧倾角度增加，驾驶员的腰椎L4受到负荷也增加，特别是剪切力的增加速度比轴向力的增加速度快，当拖拉机从0°倾斜到15°时，驾驶员的L4受到的剪切力从0N增加到138.7N。（3）驾驶员腰椎L4-L5椎间盘的最大Von-Mises应力和最大应变会因倾斜而增加。最大Von-Mises应力发生在椎间盘环II（侧倾15°时，静态最大为5.286Mpa，动态最大为7.643Mpa)，最大应变发生在椎间盘的上端板(侧倾15°时，静态最大为0.495mm，动态最大为0.720mm）。随着倾斜的发生，最大Von-Mises应力的位置会发生变化。结果表明拖拉机侧倾会加速驾驶员的肌肉疲劳，并对驾驶员的腰椎造成损伤，且振动会加剧这种影响。.在揭示驾驶员腰椎损伤主要原因的基础上，设计了结构紧凑的座椅椅面调平机械装置，基于人机交互舒适性原则开发了高精度调平装置控制系统，实现了驾驶员的腰部均匀受力，提高了驾驶员操作适应性有促进作用。此外，项目还开展了拖拉机辅助驾驶技术研究，降低驾驶员方向盘操纵劳动强度，提高驾驶员田间作业的舒适性。.项目执行期间，发表SCI/EI论文12篇，申报发明专利２项，培养研究生3名（硕士毕业），完成项目规定的各项任务。