铰接转向工程车辆侧倾稳定性研究

发布时间：2018-01-09 10:21

本文关键词：铰接转向工程车辆侧倾稳定性研究　出处：《吉林大学》2013年博士论文　论文类型：学位论文

【摘要】：铰接转向工程车辆行驶路面复杂，工作环境恶劣，并且转弯时车辆重心会发生横向偏移，导致翻车事故发生几率较高。本文结合国家自然科学基金项目“非公路车辆防翻车主动安全技术研究”（NO.51175216）和高等学校博士学科点专项科研基金项目“工程车辆主动防倾翻系统设计理论与控制技术”（NO.20100061110014），对铰接转向工程车辆的侧倾稳定性进行系统研究，以轮式装载机为研究对象，提出了适用于铰接转向工程车辆的侧倾稳定性指标，并建立了7自由度非线性侧倾动力学模型，利用物理样机试验和虚拟样机仿真对所建立的动力学模型进行了验证，提出了改进铰接转向工程车辆的侧倾稳定性的措施。在综述国内外铰接转向工程车辆侧倾稳定性研究成果的基础上，结合铰接转向工程车辆的特性以及侧倾失稳原因，分析了铰接转向角、侧向加速度以及侧倾角等因素对现有指标的影响，讨论了现有各稳定性评价指标在铰接转向工程车辆上应用的不足，提出了适用于铰接转向工程车辆的侧倾稳定性指标。基于拉格朗日方程及虚功原理，建立了轮式装载机的7自由度非线性侧倾动力学模型，该模型全面考虑了车辆横摆、侧倾、俯仰等3个转动自由度以及纵向、横向、垂向3个平动自由度和后桥摆动自由度。模型以车辆的结构参数、铰接转向角、坡度角以及车速等作为输入，以车辆的动力学和运动学特性如侧倾角、侧倾角速度、侧向加速度、横向载荷转移率等作为输出。采用后向差分法对所建立的模型进行了数值求解。为验证所建立的动力学模型的可靠性，设计并制造了某型号铰接转向装载机的物理样机模型，进行了平面转弯，斜坡转弯以及越障等工况的试验；建立了铰接转向装载机虚拟样机模型，进行了对应工况下的虚拟样机仿真。通过对比侧倾动力学模型仿真结果、试验结果以及虚拟样机仿真结果，，发现三者吻合程度较高，从而验证了所建立的动力学模型的正确性。利用7自由度非线性侧倾动力学模型，对某轮式装载机的侧倾稳定性进行了详尽的分析。所分析的参数中包括转弯速度、转弯半径、铰接转向角速度、坡度角、前桥到铰接轴线的距离、后桥到铰接轴线的距离、轮距以及摆动桥等。结果显示，摆动桥的存在对车辆在水平路面上的侧倾稳定性影响不大但对其在坡路上的侧倾稳定性影响非常大。分析结果对改进车辆的侧倾稳定性设计有一定的参考价值。根据铰接转向工程车辆侧倾稳定性分析结果，提出了基于摆动桥的改进方案。该方案中在现有的被动式摆动桥基础上增加检测组件、控制组件以及液压组件，使其成为主动式摆动桥；当车辆在水平路面上行驶时，该主动式摆动桥所实现的功能与被动式摆动桥基本一致，不会影响到车辆的越障性能；当车辆在坡路行驶时，该主动式摆动桥将会限制后桥的摆动以增强其侧倾稳定性。对改进后的车辆进行了仿真分析，结果显示该方案可以提高铰接转向工程车辆的侧倾稳定性。本文建立了全面分析铰接转向工程车辆特性的侧倾动力学模型，提出了适用于铰接转向工程车辆的侧倾稳定性指标，并将被动式摆动桥改进为主动式摆动桥以提高车辆侧倾稳定性。论文的研究工作为铰接转向工程车辆的安全性设计及主动防倾翻安全技术的开发提供了依据，对于提高铰接转向工程车辆作业的安全性和保护司机的生命安全具有重要意义。
[Abstract]:Articulated engineering vehicles Road complex, poor working environment, and the center of gravity of the vehicle when turning lateral offset, resulting in a rollover accident probability is high. Non road vehicle anti rollover active safety technology research based on the National Science Fund Project "(NO.51175216) and SRFDP research foundation project of engineering vehicle active rollover design theory and control technology system" (NO.20100061110014), a systematic study of lateral stability of articulated engineering vehicles, the wheel loader as the research object, put forward roll stability indicator for articulated engineering vehicles, and the establishment of a 7 degree of freedom nonlinear dynamic model of the roll, the models verified by physical prototype and virtual prototype simulation, put forward the improvement of articulated engineering vehicles Measures for the stability of the tilting.
Based on engineering vehicle steering roll stability research results at home and abroad is on the stability of articulated engineering vehicles with characteristics and rollover analysis, articulated steering angle, lateral acceleration and roll angle and other factors on the existing indicators, discusses the evaluating indexes of stability understeering vehicle in engineering application is put forward roll stability indicator for articulated Engineering vehicles.
The Lagrange equation and based on the principle of virtual work, established 7 degrees of freedom nonlinear dynamic model of roll wheel loader, the model fully considers the yaw, roll, pitch and 3 rotational degrees of freedom and the longitudinal, transverse and vertical 3 translational degrees of freedom and freedom. After the swing bridge model with structural parameters the vehicle, articulated steering angle, slope angle and vehicle speed as input to dynamic and kinematic characteristics of the vehicle such as roll angle, roll angle speed, lateral acceleration, lateral load transfer rate as output. Using backward difference method to establish the model of numerical simulation is carried out. The reliability of dynamic model was established by to verify the design and manufacture of an articulated steering physical prototype model of the loader, the plane turning, turning and climbing slope test conditions; establish articulated loader virtual prototype The virtual prototype simulation under the corresponding working conditions is carried out. By comparing the simulation results of the lateral dynamics model, the experimental results and the simulation results of the virtual prototype, it is found that the three coincides well, which validates the correctness of the established dynamic model.
The use of 7 degree of freedom nonlinear dynamic model of the roll, the roll stability of a wheel loader was analyzed. The analyzed parameters including turning speed, the turning radius, articulated steering angular velocity, slope angle, front axle to the hinge axis distance to the rear axle articulation axis distance, tread and swing bridge. The results showed that there is a swing bridge has little influence on the roll stability of the vehicle in a horizontal road but the influence of roll stability in the slope of the road is very large. The analysis results have certain reference value for the design of improved vehicle roll stability.
According to the analysis results of engineering vehicle roll stability of articulated steering, put forward the improvement scheme based on swing bridge. The scheme in passive swing bridge on the basis of the existing increase detection components, control components, hydraulic components, make it become the active swing bridge; when the vehicle is traveling in the water on the road surface, the realization of the active swing bridge function and passive swing bridge is basically the same, will not affect the obstacle performance of the vehicle; when the vehicle on the slope road when the active swing bridge will limit the rear axle swing to enhance the lateral stability of the improved vehicle is simulated. The results show that this scheme can improve the lateral stability of engineering vehicle steering articulated.
Roll dynamics model is established in this paper a comprehensive analysis of characteristics of articulated engineering vehicles, the roll stability index for articulated engineering vehicles, and the improved swing bridge for active passive swing bridge to improve vehicle roll stability. Provide the basis for the development of security technology in double safety design on paper as articulated steering engineering vehicle and active defense, has important significance for the safety of life safety and protect the driver to improve the engineering vehicles are articulated.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH113.25;TH243

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