【作者】 玄圣夷；

【导师】 宋传学；

【作者基本信息】 吉林大学 ， 车辆工程， 2010， 博士

【摘要】 汽车电子稳定性控制(ESP,Electronic Stability Program)系统是一种基于主动调节制动力、驱动力的车辆底盘主动安全控制系统,可以有效提高车辆的行驶稳定性。本文针对ESP系统中基于主动干预制动力的制动防抱死控制系统(ABS,Anti-lock Brake System)和主动横摆力矩控制系统(AYC,Active Yaw Control)的关键技术展开了深入的理论和试验研究。首先针对汽车行驶稳定性控制中的关键问题路面附着系数估计和汽车行驶状态算法进行了研究,并提出了基于车辆模型和动力学原理的路面附着系数联合估计算法、基于自适应Kalman滤波算法的汽车状态预测方法,有效提高了路面附着系数和车辆状态估计的精度。围绕制动防抱死系统在良好路面的制动防抱死控制、分离路面的制动方向稳定性控制策略和基于横摆角速度和质心侧偏角联合控制的主动横摆力矩控制策略进行了基本控制策略的研究。以此为基础,开发了制动防抱死控制和主动横摆力矩控制的协调控制逻辑与算法,并提出了制动防抱死控制系统和主动横摆力矩控制系统的评价方法。根据控制策略开发的需要,利用搭建的汽车稳定性控制系统硬件在环实验台,对所设计的控制算法的有效性和准确性进行了验证。仿真和试验结果表明,所开发控制算法和逻辑在各种工况下能够有效的提高汽车的行驶稳定性,所提出的评价方法能对汽车底盘电控系统进行有效评价。本文设计的制动防抱死控制策略、主动横摆力矩控制策略及二者的协调控制策略对汽车稳定性控制系统的开发具有重要参考意义。更多还原

【Abstract】 based on controlling brake system and driving torque actively. With the rapid development of automotive chassis electronic control technology, ESP has been more and more widely used in modern cars, and the system make a significant role in improving the stability and safety of vehicles. Now many major automobile manufacturers and research institutions have carried out their products on ESP,and ESP will become the standard installation in modern cars.This paper introduces the Anti-lock Brake System (ABS) and Active Yaw-moment Control (AYC), then control strategies and performance evaluation methods have been carried out. Firstly, the estimation of road surface coefficient and the estimation algorithm of sideslip angle which is difficult to be measured have been brought out. According to above, yaw rate and sideslip angle feedback control strategy of AYC system is presented in Chapter 2. Secondly, the ABS basic control strategy is designed then yaw moment control algorithm in ABS system is researched. Thirdly the integrated control strategy of ABS and AYC has been put forward. The chassis stability control strategy for vehicle on longitudinal and lateral dynamics in critical states is introduced. A vehicle braking system hardware in the loop test bench is established based on real time rapid prototyping technology. Utilizing the test bench, hardware in the loop simulation for ABS, AYC and integrated control algorithms of ABS and AYC have been validated. Finally, vehicle dynamics principle and the system characteristics, the ABS and AYC system performance evaluation method is proposed. Combined with HILS the effectiveness of the evaluation methods are validated. The paper mainly includes the following details:1. Vehicle states and road adhesion conditions estimation Based on self-adaptive Kalman filtering theory and vehicle dynamics model, the sideslip angle estimation algorithm has been brought out for AYC control system design. The algorithm validation has been carried out with vehicle test data. The results show that method can estimate the value of sideslip angle accurately when the vehicle is driving. On the basis of adaptive Kalman filtering theory, a recursive algorithm has been researched. The vehicle yaw rate estimation methods and algorithm validation have been tested and verified with vehicle test data. Road adhesion conditions play an important role in AYC and ABS control strategies. According to vehicle wheel dynamic principle, Timothy tires and road empirical model, road conditions attached estimation algorithm has been established by dividing the road coefficient into three cases: 0.8, 0.5 and 0.2.2. ABS control strategiesFirst, an improved sliding mode control method based on reaching law has been proposed to solve the vibration problem in traditional sliding mode control. The ABS basic antilock control strategy has been designed based on the improved sliding mode control method. On this basis, braking distance and directional stability as the measure standard, the ABS single wheel depending on yaw rate predictive value feedback closed-loop control strategy has been designed. Ensuring the braking direction stability, making the braking distance as shorten as possible, enhancing the control performance of ABS comprehensive, this ABS control strategy has improved the ABS control effect on split road3. AYC control strategiesThe active yaw-moment control algorithm establishes yaw moment depending on two reference control parameters: yaw rate and sideslip angle. According to the characteristics of driving conditions and the combination control with robust control and PID algorithm, the yaw rate control and sideslip angle control based on multi-stage robust PID control strategy are proposed respectively. The yaw rate and sideslip angle can reflect the status of vehicles in different driving condition. The combination control strategy can improve the control quality of the AYC and effectively enhance the vehicle’s lateral driving ability.4. Integrated control strategy for ABS and AYC ABS and AYC systems are both based on active brake system to realize vehicle active safety control, but their action system is different, so it is necessary to research on the integration of two control strategies. In this paper, the integrated control strategy when ABS and AYC reach the threshold at the same time have been studied. The integrated control strategy of ABS and AYC based on the control priorities and vehicle’s stability margin is carried out. It is determined the priority of ABS is higher than AYC, then AYC control strategy is used secondary to realize the vehicle stability control.5. Hardware in the loop experimental studyESP system hardware in the loop test bench has been built by using Matlab / xPC Target rapid prototyping technology. The hardware of the test bench includes vehicle braking system and steering wheel, etc. The software of the bench includes vehicle dynamics simulation software-using Matlab /Simulink to provide driving environment and vehicle states, in order to build a person - vehicle - road closed-loop driving environment. ABS and AYC control algorithms has been validated through the hardware in the loop experiment. Hardware-in-loop simulation results show that: (1) the Designed AYC and ABS control strategies can realize the basic vehicle yaw stability control and antilock braking control. (2)ABS control strategy of single wheel can effectively guarantee the directional stability when vehicles brake on split road and the ABS control can effectively shorten the braking distance. (3) The integrated control strategy of ABS and AYC can achieve the stability control when vehicles reach the dynamics critical states.6. ABS and AYC performance evaluation methodAccording to vehicle assessment standards and ABS and AYC system characteristics, the objective evaluation methods of ABS and AYC have been brought out. First, according to vehicle driving conditions and performance requirements, a corresponding evaluation test conditions have been presented. Combined with driver’s subjective feelings, the limits of each evaluation has been carried out. For the ABS and AYC integrated control, the test conditions which can simultaneously make ABS and AYC work have been designed. Based on above research results the integrated control performance evaluation method is presented. Finally an objective evaluation method for ABS, AYC, and integrated control has been established.Through above research, the conclusions of this paper are as follows:(1) Multi-level threshold control strategy of yaw rate and side slip angle can effectively solve the integrated problem in vehicle stability control. Yaw rate and side slip angle can always been kept within reasonable limits through different threshold settings, and enhancing the stability of vehicle effectively.(2) Based on the yaw rate predictive feedback, ABS control strategy of single wheel could solve the contradiction between the braking direction stability and braking distance when vehicles run on split road. To guarantee the stability of vehicle braking direction the braking distance can become shorten through a single wheel braking regulation.(3) Based on the performance characteristics of electronic control system and the influence of vehicle performance the objective evaluation method is designed .And the method can evaluated ABS and AYC system performance effectively. The evaluation methods can provide reference for ABS and AYC system control strategy.(4) Vehicle braking system hardware in the loop test bench based on rapid prototyping technology can enhance the safety and development efficiency. The test bench can also play the role of validation and guidance in ABS and AYC system development. It is an effective chassis active safety electronic control system tool.更多还原