商用车制动防抱死系统的弯道制动控制算法研究
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摘要
制动防抱死系统(ABS)是20世纪汽车电子最伟大的发明之一,为了提高ABS在弯道的性能,需要对其进行优化。在弯道上制动的车辆由于受离心力的影响,会发生轴荷转移,使得弯道内侧的车轮载荷减少,外侧载荷增大,整个轴的平均侧偏刚度减少,载荷转移越大,平均侧偏刚度下降得越快,而侧偏刚度下降导致车轮能够提供的侧向力和纵向力都会减少,而且最大侧向力对应的目标滑移率也发生了变化,本文就是针对这种情况,考虑到轴荷转移对滑移率的影响,优化目标滑移率,从而提高制动的方向稳定性和制动效能。弯道识别是弯道控制的前提,只有在知晓弯道的情况下,才能采取有别于其他的路况下的制动控制算法。因此必须进行转向的识别。由于本文是基于ABS的因此它可用的信号就只有轮速信号,本文通过对轮速信号进行处理,得到驱动情况下的转向因数K和制动情况下同轴弯道内外侧轮滑移率之差,利用这两个参数在驱动和制动下时识别弯道。结果显示这种方法可以有效的识别弯道,不需要额外的设备,稳定性好。本文采取的是滑移率的控制,因此参考车速的估算是本文的又一重点。车辆在弯道驱动时,其参考车速去四个车轮轮速的均值最接近实际车速。当车辆在弯道制动时,其参考车速取轮速波动最少轮可以得到最接近实际车速的参考车速。本文在平均轮速法的基础上加上轮速甄别程序,使车辆在驱动时取平均轮速,制动时取最大值。
The centrifugal force leads to the load transfer between the inner and outside tires of the cornering, when the vehicle is braking on the cornering. The load of inner tires decreases and the load of outside tires increases. The transfer occurs more heavily, and the cornering stiffness is less, and the slip angle of tire is bigger. Because the changes of the slip angle of tire and the vertical force of tire, the target slip ratio for every wheel should be varied. This article aims to improve the brake performance of the vehicle on the cornering by fuzzy control of the optimized slip ratio.
The article is comprised of five chapters:
The first chapter is the introduction. It introduces the general structure and theory of the Anti-lock Brake System, and expounds the relation between the cornering braking system and the ABS, then summarizes the overseas and domestic study statue of the task. The main study content is put forward at last.
The second chapter is the modeling of the vehicle dynamics. The vehicle model of the 8 degrees freedom is established including the longitudinal, lateral, yaw, roll degree freedom and four wheel vertical degrees freedom. The brake and the tire is modeled in the end. This work is the foundation of simulation.
The third chapter is the estimation of the reference speed and cornering detection and control. The control arithmetic bases on slip ratio control. The precision of the slip ratio directly influences the final control effect. If the estimation of the reference speed is too small, the wheel will be control on the unstable area, otherwise, if the estimation of the reference is too big, then the actual slip ratio is below the target slip ratio , and the braking efficiency is low. This article introduces the wheel speed distinguished beyond the method of the average wheel speed, which can improve the precision of the estimation of the reference speed. When the vehicle is under the condition of drive on the cornering, the average value of the four wheels’speed is close to the actual speed of the vehicle.
When the vehicle is under the condition of braking, the choice of the wheel which is the most close to the vehicle speed is reasonable. If the vehicle is braking, most of the wheel speed would be abandoned for the fluctuation of the wheel speed. This article analyses the theory of the estimation of the reference speed, sets up the particular flow chart, and makes the block of the estimation of the reference speed using software MATLAB. Cornering identification is the precondition of the cornering braking control. This test introduces the method of software and hardware for cornering identification. The wheel speed is used to identify the cornering because of the foundation of ABS. the method of difference of the inner and outside wheel speed and, method of turning factor and the method of difference of the inner and outside slip ratio have been analyzed and compared and then a better way to diagnose the cornering is obtained. This means can recognize mu split and cornering in the same time. In the last of the chapter, the means of optimized target slip ratio has been brought forward.
The conventional means of fixed target slip ratio will result that the slip ratio of the front. left wheel is too small and that of the front. right wheel is too big which will lead to the low brake efficiency and vehicle instability. Because the front axe influences the brake efficiency mostly, this method is used in the front axe and the rear axe takes the method of the fixed slip ratio.
The forth chapter tells the control arithmetic and the design of the fuzzy controller. The control for ABS is comprised of the method of limited value and that of slip ratio. This paper adopts the method of slip ratio control because of the complexity and precision of the cornering braking. The controller has two inputs and one output. The slip ratio and the differential coefficient of the slip ratio are the input signal and the variation value of the brake pressure is the output. The input value is divided into five parts, and the output five parts. The controller can be designed using the MATLAB.
The fifth chapter is the simulation and analyze of the arithmetic of the cornering braking control. The simulation model is obtained by the control arithmetic of the third chapter and the controller of the forth chapter. The curves of the wheel speed and vehicle speed, the slip ratio, the braking moment, the vertical force of the tyre and the lateral acceleration of vehicle body are compared between fuzzy control and the traditional limited value control in open loop and close loop. The stabilization and performance of braking are taken into account. Through the comparison, it is clear that the braking performance of the fuzzy control is similar with that of the limited value control and the braking stabilization of the fuzzy control is better than that of limited value in the low mu road surface in the other hand, the braking performance of the fuzzy control is better than that of the limited value control and the braking stabilization of the fuzzy control is similar with that of limited value in the high mu road surface. in a word the fuzzy control is better than the limited control.
The sixth chapter is the full conclusion of the article and the research prospect. The next study emphasis is that the cornering braking control assorts with the ESP and improving the performance of the cornering braking.
The centrifugal force leads to the load transfer between the inner and outside tires of the cornering, when the vehicle is braking on the cornering. The load of inner tires decreases and the load of outside tires increases. The transfer occurs more heavily, and the cornering stiffness is less, and the slip angle of tire is bigger. Because the changes of the slip angle of tire and the vertical force of tire, the target slip ratio for every wheel should be varied. This article aims to improve the brake performance of the vehicle on the cornering by fuzzy control of the optimized slip ratio.
The article is comprised of five chapters:
The first chapter is the introduction. It introduces the general structure and theory of the Anti-lock Brake System, and expounds the relation between the cornering braking system and the ABS, then summarizes the overseas and domestic study statue of the task. The main study content is put forward at last.
The second chapter is the modeling of the vehicle dynamics. The vehicle model of the 8 degrees freedom is established including the longitudinal, lateral, yaw, roll degree freedom and four wheel vertical degrees freedom. The brake and the tire is modeled in the end. This work is the foundation of simulation.
The third chapter is the estimation of the reference speed and cornering detection and control. The control arithmetic bases on slip ratio control. The precision of the slip ratio directly influences the final control effect. If the estimation of the reference speed is too small, the wheel will be control on the unstable area, otherwise, if the estimation of the reference is too big, then the actual slip ratio is below the target slip ratio , and the braking efficiency is low. This article introduces the wheel speed distinguished beyond the method of the average wheel speed, which can improve the precision of the estimation of the reference speed. When the vehicle is under the condition of drive on the cornering, the average value of the four wheels’speed is close to the actual speed of the vehicle.
When the vehicle is under the condition of braking, the choice of the wheel which is the most close to the vehicle speed is reasonable. If the vehicle is braking, most of the wheel speed would be abandoned for the fluctuation of the wheel speed. This article analyses the theory of the estimation of the reference speed, sets up the particular flow chart, and makes the block of the estimation of the reference speed using software MATLAB. Cornering identification is the precondition of the cornering braking control. This test introduces the method of software and hardware for cornering identification. The wheel speed is used to identify the cornering because of the foundation of ABS. the method of difference of the inner and outside wheel speed and, method of turning factor and the method of difference of the inner and outside slip ratio have been analyzed and compared and then a better way to diagnose the cornering is obtained. This means can recognize mu split and cornering in the same time. In the last of the chapter, the means of optimized target slip ratio has been brought forward.
The conventional means of fixed target slip ratio will result that the slip ratio of the front. left wheel is too small and that of the front. right wheel is too big which will lead to the low brake efficiency and vehicle instability. Because the front axe influences the brake efficiency mostly, this method is used in the front axe and the rear axe takes the method of the fixed slip ratio.
The forth chapter tells the control arithmetic and the design of the fuzzy controller. The control for ABS is comprised of the method of limited value and that of slip ratio. This paper adopts the method of slip ratio control because of the complexity and precision of the cornering braking. The controller has two inputs and one output. The slip ratio and the differential coefficient of the slip ratio are the input signal and the variation value of the brake pressure is the output. The input value is divided into five parts, and the output five parts. The controller can be designed using the MATLAB.
The fifth chapter is the simulation and analyze of the arithmetic of the cornering braking control. The simulation model is obtained by the control arithmetic of the third chapter and the controller of the forth chapter. The curves of the wheel speed and vehicle speed, the slip ratio, the braking moment, the vertical force of the tyre and the lateral acceleration of vehicle body are compared between fuzzy control and the traditional limited value control in open loop and close loop. The stabilization and performance of braking are taken into account. Through the comparison, it is clear that the braking performance of the fuzzy control is similar with that of the limited value control and the braking stabilization of the fuzzy control is better than that of limited value in the low mu road surface in the other hand, the braking performance of the fuzzy control is better than that of the limited value control and the braking stabilization of the fuzzy control is similar with that of limited value in the high mu road surface. in a word the fuzzy control is better than the limited control.
The sixth chapter is the full conclusion of the article and the research prospect. The next study emphasis is that the cornering braking control assorts with the ESP and improving the performance of the cornering braking.
引文
[1]余志生.汽车理论(第三版)[M].机械工业出版社,2006.
[2]魏春源等译.汽车安全性与舒适性系统[M].北京理工大学出版社,2007.
[3]司利增.汽车防滑控制技术—ABS与ASR[M].人民交通出版社,1996-6.
[4]孙万峰.中重型汽车制动防抱死系统控制算法研究[D].吉林大学,2006-4.
[5]程军.汽车防抱死制动系统的理论与实践[M].北京理工大学出版社,1999-9.
[6] http://auto.eccn.com/pub/techview.asp?id=6174
[7] http://en.wikipedia.org/wiki/Corneringing_Brake_Control
[8] http://www.usautoparts.net/bmw/technology/cbc.htm
[9]张代胜,顾勤林,陈朝阳,尹安东,赵虎.车辆转弯制动防抱死系统仿真[J].农业机械学报,2005-9:16-20.
[10]赵六奇,金达锋译.车辆动力学基础[M].清华大学出版社,2006-12.
[11]李君,喻凡,张建武,冯金芝.车辆转向制动防抱死系统仿真研究[J].系统仿真学报,2001-11,13(6):789-793.
[12]王国业,刘昭度,崔海峰,吴利军.汽车ABS弯道制动的阶梯控制[J].汽车工程,2006年(11).
[13]宋健,孔磊,沈俊.特殊工况下的ABS控制算法[J].江苏大学学报,2006-3,27(2).
[14]汪知望,孙习武.基于模糊控制的车辆弯道防抱制动系统仿真分析[J].汽车科技2006-1(1).
[15]方锡邦,孙习武.车辆弯道防抱死制动系统仿真分析研究[J].拖拉机与农用运输车,2006-2:77-83.
[16]程军,瞿宏敏.载货汽车转弯制动模拟研究与评价[J].汽车研究与开发,1999(1):31-44.
[17]陈朝阳,顾勤林,张代胜.车辆转向时制动防抱死系统的仿真研究[J].合肥工业大学学报(自然科学版)2004-12,27(12).
[18]周英杰.对转向过程中理想制动力分配形式的理论研究[J].轻型汽车技术,2006,6:7-9.
[19]王国业,刘昭度,崔海峰,吴利军.汽车ABS弯道制动的阶梯控制[J].汽车工程,2006(11).
[20]马云杰.车辆弯道制动工况下的动力学分析[J].汽车技术,2005(5):17-20.
[21]任秉银,宋政吉,郑德林.汽车弯道制动过程仿真研究[J].哈尔滨工业大学学报,1998(10).
[22]王阳阳,章志龙.整车转弯制动控制仿真研究[J].汽车科技,2007-9(5).
[23] Shinji matsumoto, Yokohama; Takeshi Kimura, Yokosuka; Taku Takahama.Road surface friction coefficient estimating apparatus.United states patent, US 6,418,369 B2.
[24]程军瞿宏敏.车辆动力学建模和模拟的研究[J].实验与研究,1997-12.
[25]王仁广,刘昭度,齐志权,崔海峰.汽车ABS参考速度的确定方法[J].农机化研究,2006-3月(3).
[26]齐志权,刘昭度,时开斌等.基于汽车ABS/ASR/ACC集成化系统的ABS参考车速确定方法的研究[J] .
[27] Device For Detecting Vehicle Speed Of Four. wheel Vehicle For Use.US Patent, No.6302500B1.
[28]刘巧玲.理论力学(第二版)[M].吉林科学技术出版社.
[29] Device for Detecting Vehicle Speed of Four. Wheel Vehicles for Use in ABS.US Patent, No.6302500.
[30]杨拯民,李伟.汽车制动过程中瞬时车速和轮速的仿真计算[J].合肥工业大学学报,2003,23(3).
[31] Device for Estimating Reference Wheel Speed of Vehicle for Turn Stability Control.US Patent, No.5879061.
[32] Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over. Steered Cornering.US Patent, No. 6580995.
[33]李守卫.基于轮速信号的侧向加速度估算和弯道制动控制算法研究[D].吉林大学,2008-6.
[34]喻凡,林逸,汽车系统动力学[M].机械工业出版社,2005-9.
[35] Turn Control Apparatus For A Vehicle.US Patent, No.5826951.
[36] Circuit Configuration for a Brake System with Anti-lock Control and/or Traction Slip Control.US Patent, No.5270933.
[37] Egbert,Bakker ,Lars,Nyborg.Tyre Modeling for Use in Vehicle Dynamics Studies[J],SAE870421.
[38] Taheri S.An.An Investigation and Design of Slip Control Braking Systems Integrated with Four wheel Steering[J] . Department of Mechanical Engineering Clemson University,1990.
[39]郑伟峰.汽车防抱死逻辑门限值控制算法研究[D].国防科技大学,2003-11.
[40]李国勇.智能控制及其MATLAB实现[M].电子工业出版社,2005-5.
[41] US Patent, No.6523914.Vehicle Steer ability and Driving Stability While Braking in aCurve.
[42]阎耀双.轻型客车气压ABS模糊控制研究[D] .合肥工业大学,2008-4.
[43]潘开广.汽车防抱死模糊控制策略研究[D].长沙理工大学,2007-3.
[44]薛定宇陈阳泉.基于MATLAB/Simulink的系统仿真技术与应用[M].清华大学出版社,2002-4.
[45] http://www.knorr-bremse.com
[46] http://www.wabco-auto.com/
[47] http://www.jnabs.com/
[48]汪学慧.具有EBD系统功能的ABS系统[J].汽车维修与保养,2004(07).
[49] http://en.wikipedia.org/wiki/Corneringing_Brake_Control
[50] http://www.hdzxw.com/news/2009/3-24/FD_U_Article-1-6-44-772533.html
[51] Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over-steered Cornering.US 6580995.Mar.-8-2005.
[52]陈箭.ABS&TCS控制系统的控制算法研究与仿真分析[D].吉林大学,2005.
[2]魏春源等译.汽车安全性与舒适性系统[M].北京理工大学出版社,2007.
[3]司利增.汽车防滑控制技术—ABS与ASR[M].人民交通出版社,1996-6.
[4]孙万峰.中重型汽车制动防抱死系统控制算法研究[D].吉林大学,2006-4.
[5]程军.汽车防抱死制动系统的理论与实践[M].北京理工大学出版社,1999-9.
[6] http://auto.eccn.com/pub/techview.asp?id=6174
[7] http://en.wikipedia.org/wiki/Corneringing_Brake_Control
[8] http://www.usautoparts.net/bmw/technology/cbc.htm
[9]张代胜,顾勤林,陈朝阳,尹安东,赵虎.车辆转弯制动防抱死系统仿真[J].农业机械学报,2005-9:16-20.
[10]赵六奇,金达锋译.车辆动力学基础[M].清华大学出版社,2006-12.
[11]李君,喻凡,张建武,冯金芝.车辆转向制动防抱死系统仿真研究[J].系统仿真学报,2001-11,13(6):789-793.
[12]王国业,刘昭度,崔海峰,吴利军.汽车ABS弯道制动的阶梯控制[J].汽车工程,2006年(11).
[13]宋健,孔磊,沈俊.特殊工况下的ABS控制算法[J].江苏大学学报,2006-3,27(2).
[14]汪知望,孙习武.基于模糊控制的车辆弯道防抱制动系统仿真分析[J].汽车科技2006-1(1).
[15]方锡邦,孙习武.车辆弯道防抱死制动系统仿真分析研究[J].拖拉机与农用运输车,2006-2:77-83.
[16]程军,瞿宏敏.载货汽车转弯制动模拟研究与评价[J].汽车研究与开发,1999(1):31-44.
[17]陈朝阳,顾勤林,张代胜.车辆转向时制动防抱死系统的仿真研究[J].合肥工业大学学报(自然科学版)2004-12,27(12).
[18]周英杰.对转向过程中理想制动力分配形式的理论研究[J].轻型汽车技术,2006,6:7-9.
[19]王国业,刘昭度,崔海峰,吴利军.汽车ABS弯道制动的阶梯控制[J].汽车工程,2006(11).
[20]马云杰.车辆弯道制动工况下的动力学分析[J].汽车技术,2005(5):17-20.
[21]任秉银,宋政吉,郑德林.汽车弯道制动过程仿真研究[J].哈尔滨工业大学学报,1998(10).
[22]王阳阳,章志龙.整车转弯制动控制仿真研究[J].汽车科技,2007-9(5).
[23] Shinji matsumoto, Yokohama; Takeshi Kimura, Yokosuka; Taku Takahama.Road surface friction coefficient estimating apparatus.United states patent, US 6,418,369 B2.
[24]程军瞿宏敏.车辆动力学建模和模拟的研究[J].实验与研究,1997-12.
[25]王仁广,刘昭度,齐志权,崔海峰.汽车ABS参考速度的确定方法[J].农机化研究,2006-3月(3).
[26]齐志权,刘昭度,时开斌等.基于汽车ABS/ASR/ACC集成化系统的ABS参考车速确定方法的研究[J] .
[27] Device For Detecting Vehicle Speed Of Four. wheel Vehicle For Use.US Patent, No.6302500B1.
[28]刘巧玲.理论力学(第二版)[M].吉林科学技术出版社.
[29] Device for Detecting Vehicle Speed of Four. Wheel Vehicles for Use in ABS.US Patent, No.6302500.
[30]杨拯民,李伟.汽车制动过程中瞬时车速和轮速的仿真计算[J].合肥工业大学学报,2003,23(3).
[31] Device for Estimating Reference Wheel Speed of Vehicle for Turn Stability Control.US Patent, No.5879061.
[32] Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over. Steered Cornering.US Patent, No. 6580995.
[33]李守卫.基于轮速信号的侧向加速度估算和弯道制动控制算法研究[D].吉林大学,2008-6.
[34]喻凡,林逸,汽车系统动力学[M].机械工业出版社,2005-9.
[35] Turn Control Apparatus For A Vehicle.US Patent, No.5826951.
[36] Circuit Configuration for a Brake System with Anti-lock Control and/or Traction Slip Control.US Patent, No.5270933.
[37] Egbert,Bakker ,Lars,Nyborg.Tyre Modeling for Use in Vehicle Dynamics Studies[J],SAE870421.
[38] Taheri S.An.An Investigation and Design of Slip Control Braking Systems Integrated with Four wheel Steering[J] . Department of Mechanical Engineering Clemson University,1990.
[39]郑伟峰.汽车防抱死逻辑门限值控制算法研究[D].国防科技大学,2003-11.
[40]李国勇.智能控制及其MATLAB实现[M].电子工业出版社,2005-5.
[41] US Patent, No.6523914.Vehicle Steer ability and Driving Stability While Braking in aCurve.
[42]阎耀双.轻型客车气压ABS模糊控制研究[D] .合肥工业大学,2008-4.
[43]潘开广.汽车防抱死模糊控制策略研究[D].长沙理工大学,2007-3.
[44]薛定宇陈阳泉.基于MATLAB/Simulink的系统仿真技术与应用[M].清华大学出版社,2002-4.
[45] http://www.knorr-bremse.com
[46] http://www.wabco-auto.com/
[47] http://www.jnabs.com/
[48]汪学慧.具有EBD系统功能的ABS系统[J].汽车维修与保养,2004(07).
[49] http://en.wikipedia.org/wiki/Corneringing_Brake_Control
[50] http://www.hdzxw.com/news/2009/3-24/FD_U_Article-1-6-44-772533.html
[51] Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over-steered Cornering.US 6580995.Mar.-8-2005.
[52]陈箭.ABS&TCS控制系统的控制算法研究与仿真分析[D].吉林大学,2005.