基于轮速信号的侧向加速度估算与弯道制动控制算法研究
摘要
在弯道上制动的车辆由于轴荷的转移使得车辆向弯道内侧行驶,即发生过度转向。当车速很高时驾驶员无法及时纠正车辆的行为,甚至发生错误的操作加重车辆的不稳定。而传统的ABS和EBD都无法通过分配制动压力矩来避免车辆在弯道上制动时的过度转向趋势。因此为了避免弯道制动时产生的过度转向,本文针对弯道制动控制算法进行了研究。
侧向加速度是弯道制动控制系统重要的控制量之一,而且也是参考车速和滑移率修正的基础,因此首先必须计算出可靠的侧向加度才能够进行弯道制动控制。为节约成本,本文采用ABS轮速传感器的信号来估算侧向加速度。通过仿真的验证表明:本文的提出的侧向加速度的估算精度高、可靠性好,完全满足弯道制动控制的要求;弯道制动控制通过减少弯道内侧车轮的制动力矩解决了车辆弯道制动时过度转向问题,改善了车辆在弯道上的制动性能,增强车辆行驶安全性。
During braking on a curve, a lot of vehicles may exhibit a turn-inward tendency due to weight transfers, namely occur oversteering. When the vehicular velocity is very high, the driver can not correct vehicular performance immediately; even cause wrong operation which aggravates the vehicles instability. Traditional ABS and EBD can not allocate brake pressure for avoiding oversteering tendency when the vehicle is braking on a curve. So curving braking control (CBC) system is proposed in this paper.
The full text is divided into five chapters.
Chapter one is introduction. CBC working principles and domestic and foreign development status quo are intruded, besides the content of the dissertation is put forward also.
The calculations of CBC external control quantities, such as lateral acceleration, reference speed and slip ratio are introduced in chapter two. In this chapter, lateral acceleration is estimated by wheel speed sensor signal and points out that the estimation is disturbed by a lot of uncertain factors, for instance, manufacturing tolerance of vehicle system, tire wear, load change, tire pressure change, spare tire and so on. So, it is necessary to modify the estimated value and limit its maximum value to prevent CBC from controlling the vehicle by mistakes. The reference speed and slip ratio are also modified by the lateral acceleration value after finishing its estimation when the vehicle is driving on a curve.
The maximum wheel speed law is applied to estimate vehicle reference speed in this paper. Four wheel speed values are not the same in most cases on a curve. In general situation, the outside wheel speeds are faster than inside wheel speed, the front wheel speeds are faster than rear wheel speeds. For calculating curving reference speed, the wheel speeds must translate into the center of gravity (CG) speeds, and then obtain reference speed by maximum wheel speed law. Before translating the wheel speeds into CG speeds, the speed deviations between the wheel speeds and CG speeds should be calculated. If the outside wheel speed is the largest one, it should subtract the deviation to obtain CG speed. On the contrary, if the inside wheel speed is the largest one, it should add the deviation. The method is also applied for the front wheels and rear wheels.
Besides modifying curving reference speed, the curving slip ratio is needed to be modified too. The slip ratio stands for slip extent of tire. For driving on straight line, the slip ratio could be calculated by the slip ratio calculation formula directly. But, when the vehicle is turning, the CG speed is different from wheel speeds. In order to obtain curving slip ratios of individual wheels, it is necessary to translate the reference speed into the speeds at the points of wheels. Then the curving wheel slip ratios which are related to slip extent of tire are calculated from these speed values.
Cornering identification, oversteering identification and CBC algorithm are introduced in chapter three. The CBC only activates during cornering, so cornering identification should be done in advance. In this paper, slip ratio or wheel speed deviation is selected according to different driving situation to identify cornering. Besides, the lateral acceleration and slip ratio are used for identifying oversteering. If the vehicle occurs oversteering, the CBC makes sure the brake pressure of inside wheels reduce immediately to prevent oversteering. Actually, the CBC mainly keeps outside wheels pressure constant and reduces inside wheels pressure. When the vehicle is braking on a curve, the CBC reduces inside wheel brake torque to create yaw torque which makes the vehicle turn outward.
The simulation of CBC is introduced in chapter four. In chapter two and chapter three, the CBC external control quantities calculation and internal control algorithm are proposed. Based on these theories, the simulating models are built up in the Matlab/Simulink environment. The vehicle model is from CarSim software and the driver model was built up by the other team members. The simulation results show that the lateral acceleration estimation is reliable and with high precision, the corrective reference speed and slip ratios approach actual values closely and the CBC improves the cornering brake control performance and alleviates the driver’s fatigue of driving.
Chapter five is the full text conclusion and research prospect. In this chapter, the next key point of research is that CBC works harmoniously with ABS, EBD and other active safety systems, so that further improve cornering braking performances.
In short, the CBC system which is described in the paper could improve cornering braking performances in certain extent, and based on which extends active safety system function.
侧向加速度是弯道制动控制系统重要的控制量之一,而且也是参考车速和滑移率修正的基础,因此首先必须计算出可靠的侧向加度才能够进行弯道制动控制。为节约成本,本文采用ABS轮速传感器的信号来估算侧向加速度。通过仿真的验证表明:本文的提出的侧向加速度的估算精度高、可靠性好,完全满足弯道制动控制的要求;弯道制动控制通过减少弯道内侧车轮的制动力矩解决了车辆弯道制动时过度转向问题,改善了车辆在弯道上的制动性能,增强车辆行驶安全性。
During braking on a curve, a lot of vehicles may exhibit a turn-inward tendency due to weight transfers, namely occur oversteering. When the vehicular velocity is very high, the driver can not correct vehicular performance immediately; even cause wrong operation which aggravates the vehicles instability. Traditional ABS and EBD can not allocate brake pressure for avoiding oversteering tendency when the vehicle is braking on a curve. So curving braking control (CBC) system is proposed in this paper.
The full text is divided into five chapters.
Chapter one is introduction. CBC working principles and domestic and foreign development status quo are intruded, besides the content of the dissertation is put forward also.
The calculations of CBC external control quantities, such as lateral acceleration, reference speed and slip ratio are introduced in chapter two. In this chapter, lateral acceleration is estimated by wheel speed sensor signal and points out that the estimation is disturbed by a lot of uncertain factors, for instance, manufacturing tolerance of vehicle system, tire wear, load change, tire pressure change, spare tire and so on. So, it is necessary to modify the estimated value and limit its maximum value to prevent CBC from controlling the vehicle by mistakes. The reference speed and slip ratio are also modified by the lateral acceleration value after finishing its estimation when the vehicle is driving on a curve.
The maximum wheel speed law is applied to estimate vehicle reference speed in this paper. Four wheel speed values are not the same in most cases on a curve. In general situation, the outside wheel speeds are faster than inside wheel speed, the front wheel speeds are faster than rear wheel speeds. For calculating curving reference speed, the wheel speeds must translate into the center of gravity (CG) speeds, and then obtain reference speed by maximum wheel speed law. Before translating the wheel speeds into CG speeds, the speed deviations between the wheel speeds and CG speeds should be calculated. If the outside wheel speed is the largest one, it should subtract the deviation to obtain CG speed. On the contrary, if the inside wheel speed is the largest one, it should add the deviation. The method is also applied for the front wheels and rear wheels.
Besides modifying curving reference speed, the curving slip ratio is needed to be modified too. The slip ratio stands for slip extent of tire. For driving on straight line, the slip ratio could be calculated by the slip ratio calculation formula directly. But, when the vehicle is turning, the CG speed is different from wheel speeds. In order to obtain curving slip ratios of individual wheels, it is necessary to translate the reference speed into the speeds at the points of wheels. Then the curving wheel slip ratios which are related to slip extent of tire are calculated from these speed values.
Cornering identification, oversteering identification and CBC algorithm are introduced in chapter three. The CBC only activates during cornering, so cornering identification should be done in advance. In this paper, slip ratio or wheel speed deviation is selected according to different driving situation to identify cornering. Besides, the lateral acceleration and slip ratio are used for identifying oversteering. If the vehicle occurs oversteering, the CBC makes sure the brake pressure of inside wheels reduce immediately to prevent oversteering. Actually, the CBC mainly keeps outside wheels pressure constant and reduces inside wheels pressure. When the vehicle is braking on a curve, the CBC reduces inside wheel brake torque to create yaw torque which makes the vehicle turn outward.
The simulation of CBC is introduced in chapter four. In chapter two and chapter three, the CBC external control quantities calculation and internal control algorithm are proposed. Based on these theories, the simulating models are built up in the Matlab/Simulink environment. The vehicle model is from CarSim software and the driver model was built up by the other team members. The simulation results show that the lateral acceleration estimation is reliable and with high precision, the corrective reference speed and slip ratios approach actual values closely and the CBC improves the cornering brake control performance and alleviates the driver’s fatigue of driving.
Chapter five is the full text conclusion and research prospect. In this chapter, the next key point of research is that CBC works harmoniously with ABS, EBD and other active safety systems, so that further improve cornering braking performances.
In short, the CBC system which is described in the paper could improve cornering braking performances in certain extent, and based on which extends active safety system function.
引文
[1]魏春源 等译,汽车安全性与舒适性系统,北京理工大学出版社,2007年1月第1版
[2]司利增,汽车防滑控制技术——ABS 与 ASR,人民交通出版社,1996年6月第1版
[3]孙万峰, 中重型汽车制动防抱死系统控制算法研究,吉林大学硕士学位论文,2006,4
[4]程军,汽车防抱死制动系统的理论与实践,北京理工大学出版社,1999年9月第1版
[5]郑伟 过学迅,车辆电控主动安全系统,汽车研究与开发,2005,NO.12
[6] US Patent, Method for Increasing the Driving Stability of a Motor Vehicle, US 7330785, Feb.12, 2008
[7] http://auto.eccn.com/pub/techview.asp?id=6174
[8] http://en.wikipedia.org/wiki/Cornering_Brake_Control
[9] http://www.usautoparts.net/bmw/technology/cbc.htm
[10]PDF Chassis and powertrain,Economical Engines Combined with Outstanding Roadholding,Opel media information
[11]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,汽车科技第1期2006年1月
[12]方锡邦 孙习武,车辆弯道防抱死制动系统仿真分析研究,拖拉机与农用运输车,2006年2月,pp.77~83
[13]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,合肥工业大学学报(自然科学版)第27卷第12期,2004年12月
[14]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,系统仿真学报,2001年11月第13卷第6期,pp.789~793
[15]王国业 刘昭度 崔海峰 吴利军,汽车 ABS 弯道制动的阶梯控制,汽车工程,2006年第11期
[16]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,农业机械学报,2005年9月,pp.16~20
[17]任秉银 宋政吉 郑德林,汽车弯道制动过程仿真研究,哈尔滨工业大学学报,1998年10月
[18]周英杰,对转向过程中理想制动力分配形式的理论研究,轻型汽车技术,2006年6月,pp.7~9
[19]王阳阳 章志龙,整车转弯制动控制仿真研究,汽车科技第 5 期,2007年9月
[20]马云杰,车辆弯道制动工况下的动力学分析,汽车技术,2005 年第 5期,pp.17~20
[21]宋健 孔磊 沈俊,特殊工况下的 ABS 控制算法,江苏大学学报(自然科学版),2006年3月
[22]程军 瞿宏敏, 载货汽车转弯制动模拟研究与评价,汽车研究与开发,1999 年第 1 期,pp.31~44
[23]赵六奇 金达锋 译, 车辆动力学基础,清华大学出版社,2006 年 12月第1版
[24]喻凡 林逸, 汽车系统动力学,机械工业出版社 2005 年 9 月第 1 版
[25]王绍銧 夏群生 李剑秋,汽车电子学,清华大学出版社,2005 年 8 月第1版
[26]张永生,商用车轮速与轮加速度信号采集与处理技术研究,吉林大学硕士学位论文,2007年
[27]项承寨 夏群生 何乐,ABS 控制量的计算研究,汽车技术,2001 年第1 期
[28]US Patent, Device for Detecting Vehicle Speed of Four-Wheeld Vehicles for Use in ABS, US 6302500, Oct. 16, 2001
[29]US Patent, ABS Reference Speed Determination, US 4989923, Feb. 5, 1991
[30]US Patent, Method for Determining a Vehicle Reference Velocity, US 7308373, Dec. 11, 2007
[31]黄安全 李亮 王会义,用于车辆动力学稳定性控制系统的参考车速实时算法研究,汽车电子技术分会第七届年会论文集,汽车制造业,pp.181~185
[32]US Patent, Device for Estimating Reference Wheel Speed of Vehicle for Turn Stability Control, US 5879061, Mar.9, 1999
[33]刘巧伶,理论力学(第二版),吉林科学技术出版社
[34]余志生,汽车理论,机械工业出版社,2004 年 1 月第 3 版
[35]Circuit Configuration for a Brake System with Anti-lock Control and/or Traction Slip Control, US 5270933, Dec. 14, 1993
[36]US Patent, Method of Improving ABS Control Behavior, US 6202019, Mar. 13, 2001
[37]US Patent, Method of Improving ABS Control Behavior on Cornering, US 6289272, Sep. 11, 2001
[38]US Patent, Method of Improving ABS Control Behavior, US 6246947, Jun.12,2001
[39]US Patent, Method of Improving ABS Control Behavior, US 6295499, Sep.25,2001
[40]US Patent, Vehicle Steerability and Driving Stability While Braking in a Curve, US 6523914, Feb. 25, 2003
[41]US Patent, Method of Improving ABS Control Behavior, US 6208928, Mar. 27, 2001
[42]US Patent Apparatus and Method of Controlling Braking of an Automotive Vehicle, Operating in a Curved Path, US 4657314, Apr. 14, 1987
[43]US Patent, Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over-steered Cornering, US 6580995, Jun.17,2003
[44] US Patent, Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over-steered Cornering, US 6580995, Mar. 8, 2005
[45]Gillespie. T. D. 1992, Fundamentals of Vehicle Dynamics, SAE, Varrendle.
[46]Milliken, W. F. and Milliken. D.L. 1995, Race Car Vehicle Dynamics. SAE, Warrendale
[47]Dixon. J. C. 1991, Tyres, Suspension and Handling, Cambridge University Press
[48]于良耀 王会义 宋健 祁雪乐 孔磊,汽车 ABS 液压系统性能评价与试验研究,第四届全国流体传动及控制学术会议,pp.39~43
[49]罗明贵,基于滑移率控制的汽车横向稳定性控制算法研究,吉林大学硕士学位论文,2007年5月
[50]姚国成,汽车稳定性控制策略的仿真研究,吉林大学硕士学位论文,2007 年 5 月
[51]陈箭, ABS&TCS 控制系统的控制算法研究与仿真,吉林大学硕士学位论文,2005,4
[52]薛定宇 陈阳泉, 基于 MATLAB/Simulink 的系统仿真技术与应用,清华大学出版社,2002年4月第1版
[53]欧阳,乘用车 ABS/TCS/ESP HCU 的仿真与特性研究,吉林大学硕士学位论文,2007年5月
[2]司利增,汽车防滑控制技术——ABS 与 ASR,人民交通出版社,1996年6月第1版
[3]孙万峰, 中重型汽车制动防抱死系统控制算法研究,吉林大学硕士学位论文,2006,4
[4]程军,汽车防抱死制动系统的理论与实践,北京理工大学出版社,1999年9月第1版
[5]郑伟 过学迅,车辆电控主动安全系统,汽车研究与开发,2005,NO.12
[6] US Patent, Method for Increasing the Driving Stability of a Motor Vehicle, US 7330785, Feb.12, 2008
[7] http://auto.eccn.com/pub/techview.asp?id=6174
[8] http://en.wikipedia.org/wiki/Cornering_Brake_Control
[9] http://www.usautoparts.net/bmw/technology/cbc.htm
[10]PDF Chassis and powertrain,Economical Engines Combined with Outstanding Roadholding,Opel media information
[11]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,汽车科技第1期2006年1月
[12]方锡邦 孙习武,车辆弯道防抱死制动系统仿真分析研究,拖拉机与农用运输车,2006年2月,pp.77~83
[13]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,合肥工业大学学报(自然科学版)第27卷第12期,2004年12月
[14]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,系统仿真学报,2001年11月第13卷第6期,pp.789~793
[15]王国业 刘昭度 崔海峰 吴利军,汽车 ABS 弯道制动的阶梯控制,汽车工程,2006年第11期
[16]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,农业机械学报,2005年9月,pp.16~20
[17]任秉银 宋政吉 郑德林,汽车弯道制动过程仿真研究,哈尔滨工业大学学报,1998年10月
[18]周英杰,对转向过程中理想制动力分配形式的理论研究,轻型汽车技术,2006年6月,pp.7~9
[19]王阳阳 章志龙,整车转弯制动控制仿真研究,汽车科技第 5 期,2007年9月
[20]马云杰,车辆弯道制动工况下的动力学分析,汽车技术,2005 年第 5期,pp.17~20
[21]宋健 孔磊 沈俊,特殊工况下的 ABS 控制算法,江苏大学学报(自然科学版),2006年3月
[22]程军 瞿宏敏, 载货汽车转弯制动模拟研究与评价,汽车研究与开发,1999 年第 1 期,pp.31~44
[23]赵六奇 金达锋 译, 车辆动力学基础,清华大学出版社,2006 年 12月第1版
[24]喻凡 林逸, 汽车系统动力学,机械工业出版社 2005 年 9 月第 1 版
[25]王绍銧 夏群生 李剑秋,汽车电子学,清华大学出版社,2005 年 8 月第1版
[26]张永生,商用车轮速与轮加速度信号采集与处理技术研究,吉林大学硕士学位论文,2007年
[27]项承寨 夏群生 何乐,ABS 控制量的计算研究,汽车技术,2001 年第1 期
[28]US Patent, Device for Detecting Vehicle Speed of Four-Wheeld Vehicles for Use in ABS, US 6302500, Oct. 16, 2001
[29]US Patent, ABS Reference Speed Determination, US 4989923, Feb. 5, 1991
[30]US Patent, Method for Determining a Vehicle Reference Velocity, US 7308373, Dec. 11, 2007
[31]黄安全 李亮 王会义,用于车辆动力学稳定性控制系统的参考车速实时算法研究,汽车电子技术分会第七届年会论文集,汽车制造业,pp.181~185
[32]US Patent, Device for Estimating Reference Wheel Speed of Vehicle for Turn Stability Control, US 5879061, Mar.9, 1999
[33]刘巧伶,理论力学(第二版),吉林科学技术出版社
[34]余志生,汽车理论,机械工业出版社,2004 年 1 月第 3 版
[35]Circuit Configuration for a Brake System with Anti-lock Control and/or Traction Slip Control, US 5270933, Dec. 14, 1993
[36]US Patent, Method of Improving ABS Control Behavior, US 6202019, Mar. 13, 2001
[37]US Patent, Method of Improving ABS Control Behavior on Cornering, US 6289272, Sep. 11, 2001
[38]US Patent, Method of Improving ABS Control Behavior, US 6246947, Jun.12,2001
[39]US Patent, Method of Improving ABS Control Behavior, US 6295499, Sep.25,2001
[40]US Patent, Vehicle Steerability and Driving Stability While Braking in a Curve, US 6523914, Feb. 25, 2003
[41]US Patent, Method of Improving ABS Control Behavior, US 6208928, Mar. 27, 2001
[42]US Patent Apparatus and Method of Controlling Braking of an Automotive Vehicle, Operating in a Curved Path, US 4657314, Apr. 14, 1987
[43]US Patent, Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over-steered Cornering, US 6580995, Jun.17,2003
[44] US Patent, Method and Device for Recognizing Cornering and for Stabilizing a Vehicle in Case of Over-steered Cornering, US 6580995, Mar. 8, 2005
[45]Gillespie. T. D. 1992, Fundamentals of Vehicle Dynamics, SAE, Varrendle.
[46]Milliken, W. F. and Milliken. D.L. 1995, Race Car Vehicle Dynamics. SAE, Warrendale
[47]Dixon. J. C. 1991, Tyres, Suspension and Handling, Cambridge University Press
[48]于良耀 王会义 宋健 祁雪乐 孔磊,汽车 ABS 液压系统性能评价与试验研究,第四届全国流体传动及控制学术会议,pp.39~43
[49]罗明贵,基于滑移率控制的汽车横向稳定性控制算法研究,吉林大学硕士学位论文,2007年5月
[50]姚国成,汽车稳定性控制策略的仿真研究,吉林大学硕士学位论文,2007 年 5 月
[51]陈箭, ABS&TCS 控制系统的控制算法研究与仿真,吉林大学硕士学位论文,2005,4
[52]薛定宇 陈阳泉, 基于 MATLAB/Simulink 的系统仿真技术与应用,清华大学出版社,2002年4月第1版
[53]欧阳,乘用车 ABS/TCS/ESP HCU 的仿真与特性研究,吉林大学硕士学位论文,2007年5月