汽车ESP模糊自适应控制

基于模糊控制理论设计了一种模糊自适应ESP控制器,该控制器可根据反馈的车辆状态信息自动适应车速和路面附着系数的变化.采用Matlab/Smulink建立了14自由度车辆模型和控制器模型,考虑了轮胎的非线性特性对汽车转向特性与行驶稳定性的影响.仿真结果表明,该控制器能够提高汽车在高速或光滑路面上的操纵稳定性,有较强的适应性和鲁棒性.     

基于MPC的四轮转向车爆胎稳定性控制

四轮独立转向驱动汽车相比传统车辆具有更多控制自由度,具备在高曲率跟踪精度好,低附着路面操纵稳定性优越的特点。本文针对车辆在轨迹跟踪中所面对的低附着、爆胎等紧急工况,本研究采用模型预测控制理论,针对四轮转向电动汽车的横摆稳定性问题进行了探究。以横摆角速度和横向误差为控制目标,计算出最优四轮转角和直接横摆力矩,下层采用最优转矩分配并考虑轮胎摩擦圆约束,以实现对四轮驱动电动汽车的稳定性控制。在CarSim/Simulink联合仿真整车模型中,采用参数化建模设置整车参数。通过双移线爆胎工况仿真实验分析,所提出的策略能够有效地提高四轮驱动电动汽车的轨迹跟踪精度,从而提高整车的行驶稳定性。     

基于非线性模型预测控制的智能车路径跟踪算法

为解决高速工况下低附着系数复杂路面上转向和行驶稳定性等难以控制的问题,建立了6自由度整车动力学模型,在传统模型预测控制理论基础上,设计了前轮主动转向控制器,并通过CarSim和MATLAB/Simulink进行联合仿真,在兼顾路径跟踪精度和行驶稳定性的前提下,对控制器参数进行优化,使车辆在中低速下路径跟踪达到最佳状态,在较高车速下加入侧偏角软约束,以保证跟踪精度和行驶稳定性。试验结果表明,提出的控制方法能保证车辆在冰雪路面高速行驶时具备一定的转向精度和行驶稳定性。     

基于小波控制的电动汽车稳定性研究（双语出版）

针对前轮独立驱动电动汽车,研究一种基于小波控制器的驱动稳定性控制系统。为提高车辆对开路面的行驶稳定性,根据驱动轮等转矩分配控制策略,提出基于神经网络PID的驱动轮滑移率相近为目标控制策略。针对矢量控制中的电流控制,提出基于离散小波变换的电流控制器。通过CarSim/Simulink建立前轮独立驱动电动汽车联合仿真平台,进行不同工况整车性能仿真与分析,并基于A&D5435快速原型开发平台进行实车试验。仿真与试验结果表明：基于小波控制器的驱动控制系统不仅提高了车辆对开路面行驶的稳定性,而且具有更平滑、更快速的转矩响应;对开路面工况下,提出的控制策略左侧、右侧驱动轮速度仿真结果与试验结果最大偏差分别为3.43%和3.56%;等转矩分配控制策略下,左侧、右侧驱动轮速度仿真结果与试验结果最大偏差分别为3.86%和3.25%,表明了试验与仿真的一致性;对开路面仿真工况下,相比于驱动轮等转矩分配控制策略,基于神经网络PID的驱动轮滑移率相近为目标控制策略的车辆峰值质心侧偏角降低了79.57%,侧向跑偏距离降低了73.39%。     

电动汽车DYC/ASR变论域模糊集成控制EI北大核心CSCD

提出了一种集成直接横摆力矩控制(DYC)与驱动防滑控制(ASR)的四轮驱动电动汽车稳定性控制系统,协助驾驶员在紧急情况下保持对车辆的控制。采用变论域模糊控制策略,利用其内在固有的鲁棒性克服车辆严重非线性,独立调节四轮转矩以防止车辆甩尾;同时设计一个模糊控制器,对轮胎力饱和引起的侧向失稳进行开环补偿,协调控制各轮牵引力,防止车轮打滑。在不同路况下,对所提出的方法进行了J-turn仿真测试。结果表明:集成控制对高速、大转向行驶产生的扰动和路面附着系数变化引起的非线性,有比DYC更好的动态跟踪能力与自适应能力。     

考虑道路因素的智能车辆纵向运动决策与控制研究

针对智能车辆纵向运动时的交通道路适应性问题,考虑路面附着系数和前车运动速度等因素,研究了智能车辆纵向运动决策与控制方法。论文研究了基于车头时距的纵向运动决策方法并建立不同驾驶行为的目标车速模型,运用变论域模糊推理算法设计了目标加速度模型。基于纵向动力学模型,运用自适应反演滑模控制算法建立了驱动控制器和制动控制器。对高附着系数路面和低附着系数路面的行驶工况进行仿真试验验证,结果表明,在不同的附着系数路面和前车变速行驶条件下,智能车辆能实时、合理地决策目标车速、目标加速度,实现安全、高效、稳定的跟驰。     

基于PSO-BP优化MPC的无人驾驶汽车路径跟踪控制研究

针对模型预测控制（MPC）路径跟踪控制器在不同路面附着系数及车速下跟踪误差大的问题，提出了基于粒子群寻优（PSO）-反向传播（BP）神经网络优化MPC的无人驾驶汽车路径跟踪控制策略。首先，设计了MPC路径跟踪控制器；其次，利用PSO-BP对MPC进行优化，以控制器精度和车辆稳定性作为评价函数，获得PSO离线最优时域参数；最后，选择4种工况进行双移线跟踪对比仿真验证。结果表明：所提出的控制策略在保证行驶稳定性的条件下，低路面附着系数低速、高路面附着系数低速、高路面附着系数高速及中路面附着系数中速工况下双移线跟踪横向控制精度分别提高了50%、55%、9%和20%。     

基于多参数控制的分布式驱动电动汽车操纵稳定性控制策略研究

为改善高速低附着路面上的车辆动力学性能，本文针对分布式驱动电动汽车提出一种基于多参数控制的操纵稳定性控制策略，包括上层轨迹跟踪控制和下层转矩分配控制。上层控制器设计基于2自由度车辆模型和驾驶员预瞄偏差模型，提出了MPC轨迹跟踪控制策略，实现对侧向偏差、横摆角偏差、质心侧偏角、横摆角速度的多参数控制。下层控制器以轮胎负荷率最小为优化目标，获得4个车轮电机转矩的最优分配量，借助于7自由度动力学模型，在双移线、蛇行工况下完成了CarSim-Simulink联合仿真。结果表明：提出的控制策略改善了高速、低附着工况下的操纵稳定性和轨迹跟踪精度。     

电动汽车DYC/ASR变论域模糊集成控制

提出了一种集成直接横摆力矩控制(DYC)与驱动防滑控制(ASR)的四轮驱动电动汽车稳定性控制系统,协助驾驶员在紧急情况下保持对车辆的控制。采用变论域模糊控制策略,利用其内在固有的鲁棒性克服车辆严重非线性,独立调节四轮转矩以防止车辆甩尾;同时设计一个模糊控制器,对轮胎力饱和引起的侧向失稳进行开环补偿,协调控制各轮牵引力,防止车轮打滑。在不同路况下,对所提出的方法进行了J-turn仿真测试。结果表明:集成控制对高速、大转向行驶产生的扰动和路面附着系数变化引起的非线性,有比DYC更好的动态跟踪能力与自适应能力。     

基于四轮轮边驱动电动车的路面附着系数估算方法

路面附着系数是影响车辆行驶安全性的重要因素,利用轮边驱动电动汽车驱动力矩可以对路面利用附着系数进行观测。当观测到μ-λ曲线接近于峰值点时,将该时刻的轮胎利用附着系数作为路面峰值附着系数,并根据识别的路面峰值附着系数进行驱动防滑控制。该方法能够有效防止轮胎滑转,提高车辆行驶稳定性。     

Vehicle stability control system for enhancing steerabilty,lateral stability,and roll stability

The Vehicle stability control system is an active safety system designed to prevent accidents from occurring and to stabilize dynamic maneuvers of a vehicle by generating an artificial yaw moment using differential brakes. In this paper, in order to enhance vehicle steerability, lateral stability, and roll stability, each reference yaw rate is designed and combined into a target yaw rate depending on the driving situation. A yaw rate controller is designed to track the target yaw rate based on sliding mode control theory. To generate the total yaw moment required from the proposed yaw rate controller, each brake pressure is properly distributed with effective control wheel decision. Estimators are developed to identify the roll angle and body sideslip angle of a vehicle based on the simplified roll dynamics model and parameter adaptation approach. The performance of the proposed vehicle stability control system and estimation algorithms is verified with simulation results and experimental results.     

Enhancing roll stability of heavy vehicle by LQR active anti-roll bar control using electronic servo-valve hydraulic actuators

Rollover of heavy vehicle is an important road safety problem world-wide. Although rollovers are relatively rare events, they are usually deadly accidents when they occur. The roll stability loss is the main cause of rollover accidents in which heavy vehicles are involved. In order to improve the roll stability, most of modern heavy vehicles are equipped with passive anti-roll bars to reduce roll motion during cornering or riding on uneven roads. However these may be not sufficient to overcome critical situations. This paper introduces the active anti-roll bars made of four electronic servo-valve hydraulic actuators, which are modelled and integrated in a yaw-roll model of a single unit heavy vehicle. The control signal is the current entering the electronic servo-valve and the output is the force generated by the hydraulic actuator. The active control design is achieved solving a linear optimal control problem based on the linear quadratic regulator (LQR) approach. A comparison of several LQR controllers is provided to allow for tackling the considered multi-objective problems. Simulation results in frequency and time domains show that the use of two active anti-roll bars (front and rear axles) drastically improves the roll stability of the single unit heavy vehicle compared with the passive anti-roll bar.     

Vehicle sideslip estimation and compensation for banked road

The sideslip driving status is of fundamental importance to the stability of a vehicle. This paper presents a practical vehicle sideslip driving status estimation method that uses ESP (electronic stability program) sensors. ESP sensors such as wheel speed, lateral acceleration, yaw rate and steering wheel angle sensors are used to determine the sideslip driving status and distinguish a banked road. This estimation algorithm contains front-rear sideslip and banked road detection methods. The proposed sideslip estimation algorithm was designed to use the analytical redundancy of these sensors and Lagrange interpolation methods. The performance and effectiveness of the proposed estimation and compensation algorithm were investigated using vehicle tests. This paper presents the results of two cases that were used for the experimental verification: a curved flat road and banked road.     

基于驾驶人转向意图的双电机驱动电动汽车稳定性控制策略

为了使双电机驱动电动车在车辆稳定性控制过程中能够精确解读驾驶意图,使车辆实际行驶状态与驾驶意图期望的车辆行驶状态尽可能相符合,提出一种基于驾驶人意图辨识的稳定性控制策略.利用基于支持向量机递归特征消除(SVM-RFE)得到的特征参数构建基于长短期记忆(LSTM)模型的驾驶人转向意图辨识模型;基于转向意图识别结果,以方向...     

Handling stability improvement through robust active front steering and active differential control

The design of the integrated active front steering and active differential control for handling improvement of road vehicles is undertaken. The controller design algorithm is based on the solution of a set of linear matrix inequalities that guarantee robustness against a number of vehicle parameters such as speed, cornering and braking stiffnesses. Vehicle plane dynamics are first expressed in the generic linear parameter-varying form, where the above-stated parameters are treated as interval uncertainties. Then, static-state feedback controllers ensuring robust performance against changing road conditions are designed. In a first series of simulations, the performance of the integrated controller is evaluated for a fishhook manoeuvre for different values of road adhesion coefficient. Then, the controller is tested for an emergency braking manoeuvre executed on a split-μ road. In all cases, it is shown that static-state feedback controllers designed by the proposed method can achieve remarkable road handling performance compared with uncontrolled vehicles.     

Active front wheel steering model and controller for integrated dynamics control systems

We report a model and controller for an active front-wheel steering (AFS) system. Two integrated dynamics control (IDC) systems are designed to investigate the performance of the AFS system when integrated with braking and steering systems. An 8-degrees-of-freedom vehicle model was employed to test the controllers. The controllers were inspected and compared under different driving and road conditions, with and without braking input, and with and without steering input. The results show that the AFS system performs kinematic steering assistance function and kinematic stabilisation function very well. Three controllers allowed the yaw rate to accurately follow a reference yaw rate, improving the lateral stability. The two IDC systems improved the lateral stability and vehicle control and were effective in reducing the sideslip angle.     

Robust control of anti-lock brake system

A robust control algorithm for an anti-lock brake system is proposed. The method used is based on static-state feedback of longitudinal slip and does not involve controller scheduling with changing vehicle speed or road adhesion coefficient estimation. An improvement involving scheduling of longitudinal slip reference with longitudinal acceleration measurement is included. Electromechanical braking actuators are used in simulations, and the algorithm used in this study is shown to have high performance on roads with constant and varying adhesion coefficients, displaying nice robustness properties against large vehicle speed and road adhesion coefficient variations. Guidelines are provided for tuning controller gains to cope with unknown actuator delay and measurement noise.     

Active Roll Control of Single Unit Heavy Road Vehicles

Summary Strategies are investigated for controlling active anti-roll systems in single unit heavy road vehicles, so as to maximise roll stability. The achievable roll stability improvements that can be obtained by applying active anti-roll torques to truck suspensions are discussed. Active roll control strategies are developed, based on linear quadratic controllers. It is shown that an effective controller can be designed using the LQG approach, combined with the loop transfer recovery method to ensure adequate stability margins. A roll controller is designed for a torsionally flexible single unit vehicle, and the vehicle response to steady-state and transient cornering manoeuvres is simulated. It is concluded that roll stability can be improved by between 26% and 46% depending on the manoeuvre. Handling stability is also improved significantly.     

基于混合仿真技术的车辆横向稳定性控制系统

介绍了利用先进计算机技术和仿真软件，进行车辆横向稳定性控制器设计以及系统混合仿真的过程。首先建立了8自由度车辆动力学系统模型，然后利用前馈补偿和模糊控制策略，设计了车辆横向稳定性控制器。最后对车辆横向稳定性控制系统进行了实时混合仿真研究。仿真结果表明所设计的车辆横向稳定性控制器控制有效，实时性好，而且在道路条件和行驶条件改变时具有较强的适应性和鲁棒性。