【作者】 殷卫乔；

【导师】 李幼德；

【作者基本信息】 吉林大学 ， 车辆工程， 2008， 硕士

【摘要】 汽车的主动安全性已经越来越受到汽车消费者和各大汽车厂商的重视。牵引力控制系统TCS(Traction Control System)通过控制车轮纵向滑移率使汽车获得最佳的纵向动力学性能。当在车辆转向或行驶在分离路面上时,驱动轮过度滑转不但会使驱动性能变差,而且地面对车辆产生附加的横摆力矩,对操纵稳定性有很大的影响,同时也增加了控制的难度。本文结以某越野汽车为研究对象,在MATLAB/SIMLINK建立汽车驱动转向动力学模型,建立了离线仿真模拟平台。提出牵引力控制策略,使用油门位置控制和驱动轮制动方法,完成了牵引力控制算法研究。完成了牵引力控制算法离线仿真研究。在基于Matlab xPC Target平台的TCS硬件在环试验台完成试验。本文采用的控制策略和控制算法抑制了驱动轮过度滑转,提高车辆的动力性能和操纵稳定性能。最后,提出液压制动系统方案和液压测试实验台的方案。更多还原

【Abstract】 More and more consumers and automobile manufactures have been paying more attention to automotive active safety system. TCS(traction control system), get the optimum vertical danymics performance by controling wheel verticle sliding rates. The driving wheel will excessive slip easily when the automobile begins to start,accelerate,or climb on the road with weak attachment coefficient ,which will deteriorate the attached conditions between tyre and road surface and also will have bad impact on driving performance maneuvering performance and stability of vehicles. When the vehcles steering or driving in the seperation road, the excessive slip driving wheel not only reduce driving performance,but also produce additional yaw torque,and that have big influence in manevering perfofmance,at the same time increase the difficult of control.The dynamic characteristics of hydraulic brake system is the essential step in the studying-process of hydraulic system design and developing hydraulic brake products.It also had directly affects on braking process,so control logic design must be based on the dynamic characteristics of hydraulic brake system. However,it is difficult to establish mathematical modeling and inaccurate. All these facts showed that experimental study is the directly method in hydraulic brake system design and analysis.There are five parts in this paper:1. Automobile driving-steering dynamic model It established automobile driving-steering dynamic model,this model sets mathematical model for engine,transmission,tire and brakes etc.A seven dof whole car model is builted by Matlab/Simulink software will satisfy the simulation of different road input, vehicles start, accelerate, drive straight,steer etc.,and simulate control effects of traction control system logic.2. Traction control strategy and control algorithm studyIdentify control target of driving steer conditions: By balancing the dynamic performance of the vehicles,it will assure the vehicles with good control stability. It proposes strategy of throttle control based on yaw angular velocity and driving wheel brake control based on slip rate.And also proposes speed eatimation based on steering wheel;nominal yaw angular velocity calculation;throttle control judge and driving wheel brake judge methods and so on;it designs PI incremental throttle control and PID,fuzzyPID driving wheel brake control strategy.3. Offline simulation study of traction control algorithmIt conducted offline simulation agaist steer contditions traction control in low attachment homogeneous road;comparative analysis agaist the results of throttle control, driving wheel brake control and joint control in this paper,which are based on determined test model parameters.The results show that:by using control strategy and control algorithm can effective inhibit driving wheel excessive slip and improve vehcles dynamic performance and stability of manipulation.It verificates correctness and reliability of algorithm for straight driving simulation in separation road, the questions yaw and driving wheel excessive slip have been contrlled effectively,dynamic performance and stability of manipulation of vehcles have been improved significantly.4. TCS hardware-in-the-loop testTCS hardware-in-the-loop test was builted basing on MATLAB/xPC Target platform,including sensor, actuator,experimental platform and signal rocessing site.It conducted TCS hardware-in-the-loop test against different driving conditions in TCS hardware-in-the-loop test-bed.the results show that TCS have effective inhibition with driving wheel excessive slip,improving vehcles dynamic performance and stability of manipulation.5. Hydraulic brake system programme and hydraulic test-bed programmeIt propses hydraulic brake system programme that have TCS function on the basis of test models,it determines hydraulic parts selection. It proposes hydraulic tast-bed overrall structureof the programme, at the same time,it selects test-bed parts model. Hydraulic brake system is in the process of being built.This paper established vehcle driving-steering dynamic model and offline simulation platform in MATLAB/SIMULINK for a linght vehcle.It praposes traction control strategy;it designs control system with different control method;traction control strategy study and traction control strategy offline simulation study is finished. On this basis,it proposes hydraulic brake system programme and hydraulic test-bed programme.更多还原