Robust roll motion control of a vehicle using integrated control strategy

This paper presents an electrically actuated roll motion control of a vehicle using simulation and experimental analysis. The controller is designed with an H_∞ control scheme based on the 3 DOF vehicle model considering parameter variations, which affect the roll dynamics. To investigate the feasibility of the active roll control system, its performance is evaluated by simulation in a full vehicle model under various conditions. The Hil setup with the electrically actuated roll control system was devised and its performance was investigated through experimental works. Finally, to enhance the performance in a transient region, an integrated control strategy is presented.     

Maneuverability modeling and trajectory tracking for fish robot

This study develops a 6-DOF mathematical model for a robotic fish that considers surge, sway, heave, roll, pitch, and yaw. The model considers the conditions of a fish swimming in ocean current perturbations similar to the ocean current perturbations of the slender-body autonomous underwater vehicles. For swimming and turning behaviors, a nonlinear, dynamic, carangiform locomotion model is derived by using a planar four-link model. A 2-DOF barycenter mechanism is proposed to provide body stabilization and to serve as an actuating device for active control design. A barycenter control scheme is developed to change the center of gravity of the robot fish body by moving balancing masses along two axes. The projected torque on x and y axes propel pitch and roll angles to the desired settings. A Stabilizing controller, fish-tail mechanism, rigid body dynamics, and kinematics are incorporated to enable the fish robot to move in three dimensional space. Simulation results have demonstrated maneuverability and control system performance of the developed controller which is proposed to conduct path tracking of the robot fish as it swims under current perturbations.     

Improving vehicle performance using adaptive control techniques

This paper reviews a collaborative research programme aimed at improving vehicle performance using adaptive control techniques. Initially the design of active suspension systems is considered, and the benefits of using a non-linear controller model with an adaptive control scheme are discussed. Adaptive schemes for active roll control are then considered, and the merits of incorporating a Smith predictor to accommodate for system delays are high-lighted. Preliminary research in adaptive cruise control and collision avoidance is discussed and plans for further developments are outlined. This work was presented, in part, at the Third International Symposium on Artificial Life and Robotics, Oita, Japan, 19–21 January 1998     

Studies on improving vehicle handling and lane keeping performance of closed-loop driver–vehicle system with integrated chassis control

This study proposes a new integrated robust model matching chassis controller to improve vehicle handling performance and lane keep ability. The design framework of the H_∞ controller is based on linear matrix inequalities (LMIs), which integrates active rear wheel steering control, longitudinal force compensation and active yaw moment control. To comprehensively evaluate the performance of the integrated chassis control system, a closed-loop driver–vehicle system is used. The effectiveness of the integrated controller on handling performance improvement is tested by a vehicle without driver model under a crosswind disturbance. At the same time, both the handling and lane keeping improving performance of the closed-loop driver–vehicle system is evaluated by tracking an S shape winding road. The simulation results reveal that the integrated chassis controller not only achieves preferable handling performance and stability, but also improves the vehicle lane keep ability significantly, and can alleviate the working load of the driver.     

基于Carsim轻型货车EPS系统控制策略研究

汽车转向性能的优劣直接决定汽车驾驶的安全性,是影响汽车主动安全的重要因素。为了提高汽车在不同工况转向时的操纵动力学性能,以轻型货车为载体,利用模糊自适应PID控制策略参数自适应调整的优势,制定模糊自适应PID控制策略,在EPS系统基本的助力模式下展开研究,通过结合Carsim和Matlab/simulink建立的整车联合模型进行仿真,并和传统PID控制策略对比分析。结果表明:汽车行驶在不同的工况时,模糊自适应PID控制策略不仅能够满足在助力模式下转向的轻便性,还通过自身的参数自调整,比常规PID控制策略具有更快的响应速度和较小的超调量,系统的性能提高。研究的控制策略能够实现更好的控制效果,对轻型货车电动助力转向系统控制器的开发具有重要的意义。     

Finishing mill strip gage setup and control by interval type-1 non-singleton type-2 fuzzy logic systems

The setup and control of the finishing mill roll gap positions required to achieve the desired strip head thickness as measured by the finish mill exit X-ray gauge sensor is made by an intelligent controller based on an interval type-2 fuzzy logic system. The controller calculates the finishing mill stand screw positions required to achieve the strip finishing mill exit target thickness. The interval type-2 fuzzy head gage controller uses as inputs the transfer bar thickness, the width and the temperature at finishing mill entry, the strip target thickness, the width and the temperature at finishing mill exit, the stand work roll diameter, the stand work roll speed, the stand entry thickness, the stand exit thickness, the stand rolling force, and the %C of the strip. Taking into account that the measurements and inputs to the proposed system are modeled as type-1 non-singleton fuzzy numbers, we present the so called interval type-1 non-singleton type-2 fuzzy logic roll gap controller. As reported in the literature, interval type-2 fuzzy logic systems have greater non-linear approximation capacity than that of its type-1 counterpart and it has the advantage to develop more robust and reliable solutions than the latter. The experiments of these applications were carried out for three different types of coils, from a real hot strip mill. The results proved the feasibility of the developed system for roll gap control. Comparison against the mathematical based model shows that the proposed interval type-2 fuzzy logic system equalizes the performance in finishing mill stand screw positions setup and enhances the achieved strip thickness under the tested conditions characterized by high uncertainty levels.     

电机驱动驻车系统的非线性自抗扰控制

电机是电动汽车的动力源,能快速启动,并通过矢量控制技术精确控制输出转矩.本文针对电动汽车电子驻车系统制动问题,提出了一种采用自抗扰控制技术驱动电机实现驻车制动的有效方法.为此分析了车辆在坡道上的纵向运动学模型,结合电机数学模型和整车模型,设计了电动汽车电子驻车非线性自抗扰控制器,并搭建了闭环仿真模型.仿真结果表明,自抗扰控制系统响应性能明显优于PID控制,最后通过实验,验证所设计的控制方案对驻车过程内外扰动具有较强的鲁棒性,能够实现驻车过程快速有效制动.     

四轮驱动电动汽车稳定性预测控制器快速实现

为解决四轮驱动电动汽车在高速情况下易发生甩尾失控的安全性问题,针对整车和执行器间的动力学耦合、控制系统非线性、多变量、实时性等问题,本文采用集中式的控制策略,设计了一种车辆横摆稳定的快速非线性预测控制器,实现了整车横摆稳定和电机转矩分配的一体化控制.为了控制系统的实时实现,将非线性规划问题转化为代数方程组求解,通过解耦预测时域间方程组的耦合关系,实现时域间优化问题的并行求解,提高了控制器的计算速度.最后给出了控制器的硬件并行加速实验,完成了控制系统的硬件在环实验,实现了车辆横摆稳定系统的实时控制.实验结果表明该控制器不仅具有良好的控制性能,而且明显提升了系统实时性.     

电动车制动防抱死自适应鲁棒控制系统

为了改善电动车的可操作性和稳定性,本文进行电动车制动防抱死控制系统的研究.首先针对汽车纵向四轮模型,设计自适应鲁棒控制器.所提出的自适应控制器和自适应鲁棒控制律不仅保证了闭环系统的稳定性,而且实现了所期望的性能.然后通过试验结果证明了控制算法的有效性.尽管道路条件的变化不同,电动车制动防抱死控制系统表现出满意的控制性能.     

基于RBF神经网络滑模控制的车辆横向控制研究

针对车辆横向控制系统中滑模控制器存在的抖振现象对转向机械结构带来的损耗问题,提出了一种基于RBF神经网络的滑模控制算法。利用RBF神经网络较强的自学习能力实时在线调节滑模控制器的切换项增益参数,增强系统的抗干扰能力与动态性能。将车辆实际参数代入仿真数学模型中,在Simulink仿真环境中进行对比仿真实验,仿真结果表明:该控制算法跟踪性能好,能够有效降低滑模控制器的抖振,满足车辆横向控制要求。     

汽车转向/防抱死制动系统的无模型协同控制

汽车制动系统和转向系统相互之间存在着复杂的耦合关系,会对汽车行驶安全性和操纵稳定性造成极大的影响。为了动态补偿这种干扰影响,以无模型控制方法设计汽车整车防抱死制动控制器、整车前轮主动转向控制器及转向系统和制动系统的协同控制器,从理论上证明了设计的无模型控制系统的稳定性。最后,在MATLAB/Simulink平台上搭建了车辆模型和控制器,进行汽车转向制动控制的动态性能仿真。仿真结果表明其解决了汽车两个系统的耦合干扰,提高了汽车制动效能和转向稳定性。     

基于模糊控制策略的车辆主动悬架研究

建立了车辆整车7自由度模型的主动悬架控制的系统状态方程模型,设计了两种模糊控制策略,方法一针对整车模型,采用一种控制方法,方法二针对整车模型的运动方式,设计不同的模糊控制器,垂直振动模糊控制器,俯仰振动模糊控制器,侧倾振动模糊控制器和逻辑控制器,仿真结果表明,所设计的模糊控制器对提高车辆的舒适性与操纵稳定性有较好的效果.     

基于过程阻尼效应的电动汽车弹簧型扭振减振系统设计

为了提高电动汽车弹簧型扭振减振控制能力,提出基于过程阻尼效应的电动汽车弹簧型扭振减振方法。构建电动汽车弹簧型扭振减振的力学加载模型,采用基于直角坐标系的力矩控制方法进行电动汽车弹簧型扭振的载荷转移机构力学特征分析,构建载荷转移的电动汽车弹簧型扭振参数辨识模型,根据过程阻尼效应进行电动汽车弹簧型扭振减振的自适应调整,实现控制器参数的优化估计和辨识,基于载荷转移机构模型实现电动汽车弹簧型扭振减振系统的控制律优化设计。仿真结果表明,采用该方法进行电动汽车弹簧型扭振减振控制的自适应性较好,被控系统的跟踪误差较低,提高了电动汽车弹簧型扭振减振的稳定性。     

基于无刷直流电机控制器设计

无刷直流电机具有运行效率高、调速性能好、结构简单、维护方便、运行可靠的优点,是电动汽车驱动系统的理想动力来源;安装在电动汽车上的驱动电机所处环境复杂,工况多变,启停频繁;然而,目前电机控制器响应速度慢、控制精度低、稳定性误差大、抗干扰力弱。为了解决这些难题,通过建立无刷直流电机的数学模型,研究电机的矢量控制算法基本原理以及实现方式,设计出了电流、转速双闭环的调速控制系统,通过引入先进的控制策略来提高控制器性能;最后,通过对无刷电机控制器进行实际测试,实验结果表明,与传统 PID 控制相比,在相同的调整频率下。本次设计的控制器具有调节时间小,调速范围广,转速波动小的优点,验证了设计的可行性。     

基于模糊PID控制的列车主动悬架振动控制研究

为了研究高速列车主动悬架系统横向振动控制,将研究对象简化为二自由度1/4车悬挂模型,研究了高速列车车体的横移、侧滚为变量的列车悬挂控制系统,采用德国轨道谱作为列车的激励拟合。算法控制器选择方面,在PID控制和模糊控制的基础上,建立模糊PID控制,并建立了基于模糊PID控制的高速列车主动悬架横向振动控制系统,通过MATLAB仿真生成关系曲线,验证了模糊PID控制算法具有更好的控制效果。     

Longitudinal control of an intelligent vehicle using particle swarm optimization based sliding mode control

This paper focuses on the design of longitudinal controller for an intelligent vehicle which was built at Asian Institute of Technology based on sliding mode control. The proposed controller uses particle swarm optimization (PSO) for optimal tuning of sliding surface and controller gain in the sliding mode controller (SMC). The longitudinal control is conducted via controlling of throttle value angle using PSO-based SMC on the simplified first-order linear model of the intelligent vehicle and controlling of brake force using fuzzy logic. In order to achieve the desired headway time, integration of throttle valve angle control and brake force control is required. To obtain the optimal parameters of SMC, two equations velocity updating and position updating are applied. Firstly, the performance of proposed controller is evaluated by using MATLAB simulation to compare with conventional PD controller. Finally, the experimental results show that the proposed PSO-based SMC can perform efficiently in longitudinal control of the intelligent vehicle.     

车辆主动转向系统的鲁棒控制器设计研究

本文将H2/H∞鲁棒控制理论应用于电动助力转向系统的控制策略研究,在建立前轮转向理想跟踪模型基础上,提出一种基于H2/H∞模型跟踪技术的主动转向控制方法,并对设计的控制器进行仿真分析与对比.通过仿真分析,从理论上验证基于H2/H∞跟踪控制理论的转向控制器可以适用于汽车的EPS转向系统,能很好地跟随理想车辆转向模型,有利于提高车辆的主动安全和稳定性.     

Integrated stability control of AFS and DYC for electric vehicle based on non-smooth control

A controller which ensures the driving stability of a four-wheel-independent-drive electric vehicle (4WID-EV) is designed in this paper. The controller is structurally hierarchically designed. In order to keep the 4WID-EV running steadily, an upper-level controller integrating the active front-wheel steering control method (AFS) and direct yaw moment control method (DYC) is designed to keep the sideslip angle and yaw rate tracking the ideal values. A non-smooth control method is used to improve the closed-loop system's convergence and anti-disturbance performance. The additional yaw moment generated by the upper-level controller is distributed to four driving wheels by the lower-level controller. An optimal control algorithm is used in the lower-level controller to achieve the minimum sum of tire utilisation, and ensure the power performance and driving stability of the 4WID-EV. In order to verify the effectiveness of the designed controller, a simulation model of the stability control system is established based on Carsim-Matlab/Simulink. And the simulation is performed under double lane change road considering the disturbances. The results of the simulation show that the 4WID-EV with the designed controller achieves smaller sideslip angle than sliding-mode control and the actuator chatter is slight. Then the stability and safety of the 4WID-EV are greatly improved.     

Design of a two‐level controller for an active suspension system

The paper focuses on a control design for a vehicle suspension system in which a balance between different performance demands is achieved. The starting point of the control design is a full–car model which contains nonlinear components, i.e. the dynamics of the dampers and springs and nonlinear actuator dynamics. In order to handle the high complexity of the problem this paper proposes the design of a two‐level controller of an active suspension system. The required control force is computed by applying a high‐level controller, which is designed using a linear parameter varying (LPV) method. For the control design the model is augmented with weighting functions specified by the performance demands and the uncertainty assumptions. The actuator generating the necessary control force is modelled as a nonlinear system for which a low‐level force‐tracking controller is designed. To obtain the low‐level controller a backstepping method is proposed. As an alternative solution a feedback linearization method is also presented. The operation of the controller is illustrated through simulation examples. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

智能车载感知与侧翻预警系统的设计

为了防止汽车在行驶过程中发生侧翻,使汽车始终处在安全工况下行驶,减少交通事故,设计了一种基于ARM9的智能车载感知和侧翻预警系统,对汽车在途行驶时的侧倾角和侧倾角速度进行监测,并采用多阶递推模型对汽车侧倾姿态进行预测,当预测到侧倾达到极限工况时发出报警信息,提醒驾驶人员注意并采取相应减少侧向加速度的措施,从而达到预防汽车侧翻事故的发生,并基于VB2005,Matlab和NIMeasurement Studio开发了车载感知与侧翻预警系统软件,进行了系统仿真。实车道路试验与系统仿真实验进行了比较,结果表明:车载感知和预警系统能够及时准确预测汽车侧翻,提高汽车主动安全。