H∞ control of electrorheological suspension system subjected to parameter uncertainties

Vehicle suspension is normally used to attenuate unwanted vibration from various road conditions. The successful suppression of the vibration leads to the improvement of ride comfort as well as steering stability of the vehicle. One of attractive candidates to formulate successful vehicle suspension is to use electrorheological (ER) damper. This paper presents robust control performances of ER suspension system subjected to parameter uncertainties associated with sprung mass of the vehicle and time constant of the ER damper. After identifying dynamic bandwidth of a cylindrical ER damper operated with two different ER fluids (one has fast response characteristic, while the other slow response characteristic), a quarter car model is established by incorporating with time constant of the damping force. A robust H_∞ controller, which compensates the sprung mass and time constant uncertainties, is designed in order to suppress unwanted vibration of the vehicle. Control responses such as vertical acceleration of the sprung mass are presented in time and frequency domains. In addition, the effect of time constant of the damping force on the vibration control performance is investigated by undertaking a comparative work between fast and slow dynamic characteristics of the ER damper.     

Fuzzy Gain-Scheduling Proportional–Integral Control for Improving Engine Power and Speed Behavior in a Hybrid Electric Vehicle

With the increased emphasis on improving fuel economy and reducing emissions, hybrid electric vehicles (HEVs) have emerged as very strong candidates to achieve these goals. The power-split hybrid system, which is a complex hybrid powertrain, exhibits great potential to improve fuel economy by determining the most efficient regions for engine operation and thereby high-voltage (HV) battery operation to achieve overall vehicle efficiency optimization. To control and maintain the actual HV battery power, a sophisticated control system is essential, which controls engine power and thereby engine speed to achieve the desired HV battery maintenance power. Conventional approaches use proportional-integral (PI) control systems to control the actual HV battery power in power-split HEV, which can sometimes result in either overshoots of engine speed and power or degraded response and settling times due to the nonlinearity of the power-split hybrid system. We have developed a novel approach to intelligently controlling engine power and speed behavior in a power-split HEV using the fuzzy control paradigm for better performances. To the best of our knowledge, this is the first reported use of the fuzzy control method to control engine power and speed of a power-split HEV in the applied automotive field. Our approach uses fuzzy gain scheduling to determine appropriate gains for the PI controller based on the system's operating conditions. The improvements include elimination of the overshoots as well as approximate 50% faster response and settling times in comparison with the conventional linear PI control approach. The improved performances are demonstrated through simulations and field experiments using a ford escape hybrid vehicle.     

A Microcomputer-Controlled Powertrain for a Hybrid Vehicle

The design and testing of a microcomputer-controlled powertrain for a hybrid (heat engine/electric) vehicle are described in this paper. The detailed control strategy used and its software implementation on the Intel 8086 microcomputer are discussed. The powertrain is made up of an electric motor, gasoline engine, automatic transmission with the torque converter removed, engine and electric motor clutches, and Hy-Vo transfer chains. The drive system has been installed in vehicles and tested on a chassis dynamometer. Test results show smooth shifting of the transmission and sequencing of the clutches in the different hybrid operating modes. The overall performance of the hybrid car is good, and driveability is comparable to a conventional automobile.     

Robust control of an electromagnetic active suspension system: Simulations and measurements

This paper considers the control of a novel high bandwidth electromagnetic active suspension system for a quarter car model in both simulations and experiments. The nature of the control problem with multiple objectives that have to be optimized as well as the uncertain parameters of the plant call for an H_∞-controller. By changing weighting filters different controllers can be designed, emphasizing either comfort or handling. Using the high bandwidth of the actuator comfort can be improved by 40% over the passive BMW whilst keeping suspension travel within the same limits. Using a different controller, handling can be improved up to 30%, limited by RMS actuator force.     

Enhanced fuzzy sliding mode controller for active suspension systems

We proposed a fuzzy sliding mode controller (FSMC) to control an active suspension system and evaluated its control performance. The FSMC employed the error of the sprung mass position and the error change to establish a sliding surface, and then introduced the sliding surface and the change of the sliding surface as input variables of a traditional fuzzy controller (TFC) in controlling the suspension system. However, no substantial improvement in the ride comfort could be obtained with the FSMC relative to the TFC because the dynamic effect of the sprung mass acceleration from the bouncing tire during tire rotation was not eliminated. We have developed an enhanced fuzzy sliding mode controller (EFSMC) that maintained not only the original FSMC property but also introduced an assisted FSMC to address and compensate for this problem, and to enhance the road-holding capability of the vehicle. The assisted FSMC differs from the original FSMC only in using the sprung mass acceleration instead of the sprung mass position as a variable of the controller design. The EFSMC exhibits better control performance than either the TFC or the FSMC, in suppressing the acceleration of the vehicle body to improve the ride quality, and in reducing the tire deflection to increase the road-holding ability of a car, as confirmed by experimental results.     

Design and Control Methodology of Plug-in Hybrid Electric Vehicles

This paper systematically discusses the design and control methodologies of a plug-in hybrid electric vehicle (PHEV). Design methodology is focused on battery energy and power capacity design. Two kinds of typical batteries, namely, NiMH and Li-ion, are discussed. Control strategies focus on all electric range and charge depletion range operations. In addition, a constrained engine on and off control strategy is discussed for charge-sustained operation. Simulation has been performed for an example passenger car. The simulation results indicate that a significant amount of fuel can be displaced by electric energy in typical urban driving.      

基于安卓智能手机的车载诊断系统实现

本文主要研究了基于安卓智能手机的汽车诊断系统的实现,通过对帕萨特B5示教板进行实际测试验证了对诊断数据的处理和管理的有效性,并实现了汽车故障代码的读取及汽车实时数据的监控。     

Constant Power Acceleration Profiles for Electric Vehicles

Constant power acceleration has been shown to extend the range of electric vehicles. However, this type of acceleration generally requires accelerations above a vehiclés maximum attainable acceleration when the vehicle is at low velocities. A practical approach is to accelerate at the maximum until a velocity is reached such that constant power acceleration from that point onward does not require accelerations larger than the maximum available. To implement this approach it is necessary to know the time at which to begin constant power acceleration and the constant power to use. This paper formulates and solves this problem.     

Vehicle Stability Enhancement of Four-Wheel-Drive Hybrid Electric Vehicle Using Rear Motor Control

A vehicle stability enhancement control algorithm for a four-wheel-drive hybrid electric vehicle (HEV) is proposed using rear motor driving, regenerative braking control, and electrohydraulic brake (EHB) control. A fuzzy-rule-based control algorithm is proposed, which generates the direct yaw moment to compensate for the errors of the sideslip angle and yaw rate. Performance of the vehicle stability control algorithm is evaluated using ADAMS and MATLAB Simulink cosimulations. HEV chassis elements such as the tires, suspension system, and steering system are modeled to describe the vehicle's dynamic behavior in more detail using ADAMS, whereas HEV power train elements such as the engine, motor, battery, and transmission are modeled using MATLAB Simulink with the control algorithm. It is found from the simulation results that the driving and regenerative braking at the rear motor is able to provide improved stability. In addition, better performance can be achieved by applying the driving and regenerative braking control, as well as EHB control.     

H<Subscript>∞</Subscript> control of multiple model subject to actuator saturation: application to quarter-car suspension system

This paper deals with the H_∞ control of nonlinear systems in multiple model representation subject to actuator saturation. An application to Quarter-Car suspension system under actuator saturation is then given using the multiple model approach. The concept of so-called parallel distributed compensation (PDC) is employed for designing control system. The idea of this controller consists in designing a linear feedback control for each local linear model. To address the input saturation problem in this paper, both constrained and saturated controls input cases are proposed. In the two cases, H_∞ stabilization conditions in the sense of Lyapunov method are derived. Moreover, a controller design with larger attraction domain is formulated and solved as a linear matrix inequality (LMI) optimization problem. Our simulation results show that both the saturated and constrained controls can stabilize the resulting closed-loop suspension system and eliminate the effect of external disturbances. Indeed, the main roles of car suspension systems, which consist on improving ride comfort of passengers and the road holding capacity of the vehicle, are achieved.     

Investigation of the Energy Regeneration of Active Suspension System in Hybrid Electric Vehicles

This paper investigates the idea of the energy regeneration of active suspension (AS) system in hybrid electric vehicles (HEVs). For this purpose, extensive simulation and control methods are utilized to develop a simultaneous simulation in which both HEV powertrain and AS systems are simulated in a unified medium. In addition, a hybrid energy storage system (ESS) comprising electrochemical batteries and ultracapacitors (UCs) is proposed for this application. Simulation results reveal that the regeneration of the AS energy results in an improved fuel economy. Moreover, by using the hybrid ESS, AS load fluctuations are transferred from the batteries to the UCs, which, in turn, will improve the efficiency of the batteries and increase their life.      

车辆视图大数据深度联网应用平台技术方案

车景大数据深度网络应用平台是根据位于不同位置卡口系统的业务需求开发的,其具有快速搜索、轨迹跟踪和结构化特征提取等功能。车辆视图大数据深度联网应用平台提供了大量的应用模块,可以有效提高车祸的检出率,减少车祸的发生。该平台顺应了当前的卡口建设趋势,采用先进技术弥补了卡口数据处理的不足,解决了当前业务需求面临的问题。通过分析可以发现,其能很好地整合现有资源,以深入调查过往车辆数据为主线,从民警角度提升警务安全防控能力。在落地方案和应用场景中,该平台采用高效、经济、稳定的部署方式,可以在不改变原有前端设备的情况下,实现人、车、物的连接与分析,最终服务警用实战,为视频的深度应用奠定良好的技术基础,具有广泛的应用前景。     

Pulsed Doppler signal processing for use in mice: design and evaluation

We have developed and evaluated a high-frequency, real-time pulsed Doppler and physiological signal acquisition and analysis system specifically for use in mice. The system was designed to provide sampling rates up to 125 kilosamples/s (ksps) with software controlled data acquisition and analysis in real-time. Complex fast Fourier transforms are performed every 0.1 ms (or longer up to 10 ms) to provide 0.1-ms time resolution and using 64-1024 sample segments of the Doppler audio signals resulting in frequency resolution ranging from 122-1953 Hz. The system was evaluated by its response to frequency swept signals with slopes (accelerations) and magnitudes (velocities) comparable to actual blood velocity signals in mice. Signals up to a maximum frequency of 125 kHz and a maximum acceleration of 20 MHz/s were processed and displayed. This corresponds to a maximum velocity of 480 (960) cm/s and a maximum acceleration of 750 (1500) m/s2 when Doppler shifts are measured with a 20- (10-) MHz probe, thereby allowing us to measure high stenotic jet velocities. The directional transitions of the spectrogram across zero frequency and across Nyquist frequency (sampling rate/2) were smooth with no discernible artifacts. Signals with period as low as 2 ms were processed and displayed at sweep speed that is ten times that in clinical Doppler systems, so that measurements of small temporal events can be made with precision. Thus, the new system can measure higher blood velocities with higher spatial and temporal resolution than is possible using clinical Doppler systems adapted for use in mice.     

Evaluation of motor characteristics for hybrid electric vehicles using the hardware-in-the-loop concept

If the concept of Hardware-in-the-Loop (HIL) is applied to component testing, characteristic of component of hybrid electric vehicle in real vehicle environment can be evaluated without actually installing that component in real vehicle. In this paper, when commercially available test motor is adopted as a drivetrain of hybrid vehicle, we need to figure out which drive train configuration would be best for specific purpose. The characteristic of the motor when it is installed in the vehicle at different drive train and driving mode can be simulated and actual characteristic can be measured. Also both results can be compared. For the hardware characteristic measurement, test facility which consists of vehicle simulator and dynamometer is required. In this case, vehicle controller in the vehicle simulator is used as a vehicle controller and dynamometer is used to simulate vehicle dynamics. Two drive train types, 4-motor series, and 2-motor parallel type are proposed. Vehicle speed tracks driving cycle speed command well in both simulation and HIL implementation.     

基于FPGA实现简易数字频率计的设计

简易数字频率计的设计,采用FPGA实现对模数转换芯片A/Dtlc549的控制,对外来信号采样,实现信号从模拟到数字的转换,在单位时间内通过计数器的累加实现对频率的计数。该设计实现的频率精度为1Hz,测量范围为0～100MHz,经实际电路测试,仿真结果表明,该频率计具有较高的实用性和可靠性。     

基于Arduino的自动避障技术实现

应用Arduino控制板及红外传感器实现了小车自动避障。利用红外线接近开关传感器来获得障碍物信息,经过算法处理后,采用差速方法控制电机,从而实现小车自主避障功能。小车采用直流电机驱动的双后轮,前端万向轮的分布方式,核心数据处理模块选取Arduino控制板。对系统进行了软硬件设计,搭建起了自动避障小车实验平台,并取得了良好的实验效果。     

Adaptive sliding controller with self-tuning fuzzy compensation for vehicle suspension control

Since the hydraulic actuating suspension system has nonlinear and time-varying behavior, it is difficult to establish an accurate dynamic model for a model-based sliding mode control design. Here, a novel model-free adaptive sliding controller is proposed to suppress the position oscillation of the sprung mass in response to road surface variation. This control strategy employs the functional approximation technique to establish the unknown function for releasing the model-based requirement. In addition, a fuzzy scheme with online learning ability is introduced to compensate the functional approximation error for improving the control performance and reducing the implementation difficulty. The important advantages of this approach are to achieve the sliding mode controller design without the system dynamic model requirement and release the trial-and-error work of selecting approximation function. The update laws for the coefficients of the Fourier series functions and the fuzzy tuning parameters are derived from a Lyapunov function to guarantee the control system stability. The experimental results show that the proposed control scheme effectively suppresses the oscillation amplitude of the vehicle sprung mass corresponding to the road surface variation and external uncertainties, and the control performance is better than that of a traditional model-based sliding mode controller.     

Modeling and Simulation of Various Hybrid-Electric Configurations of the High-Mobility Multipurpose Wheeled Vehicle (HMMWV)

Although hybrid-electric vehicles have been studied mainly with the aim of increasing fuel economy, little has been done in order to improve both fuel economy and performance. However, vehicular-dynamic-performance characteristics such as acceleration and climbing ability are of prime importance in military vehicles such as the high-mobility multipurpose wheeled vehicle (HMMWV). This paper concentrates on the models that describe hybridized HMMWV vehicles and the simulation results of those models. Parallel and series configurations have been modeled using the advanced-vehicle-simulator software developed by the National Renewable Energy Laboratory. Both a retrofit approach and a constant-power approach have been tested, and the results are compared to the conventional model results. In addition, the effects of using smaller engines than the existing ones in hybrid HMMWV drive trains have been studied, and the results are compared to the data collected from an actual implementation of such a vehicle. Moreover, the integrated-starter/alternator (ISA) configuration has been considered, and the results were encouraging     

Impedance control of an active suspension system

A novel control system is developed to control dynamic behavior of a vehicle subject to road disturbances. The novelty of this paper is to apply the impedance control on an active vehicle suspension system operated by a hydraulic actuator. A relation between the passenger comfort and vehicle handling is derived using the impedance parameters. The impedance control law is simple, free of model and can be applied for a broad range of road conditions including a flat road. Impedance control is achieved through two interior loops which are force control of the actuator by feedback linearization and fuzzy control loop to track a desired body displacement provided by the impedance rule. The system stability is analyzed. A quarter-car model of suspension system and a nonlinear model of hydraulic actuator are used to simulate the control system.     

基于Zigbee技术的智能车运行状态实时监控系统

为了获取智能车在运行中的各项实时参数以及切合实际需求的控制策略,提出基于Zigbee无线通信的解决方案,设计并实现了智能车运行状态实时监控系统。实验证明,该系统能够获得智能车运行中的实时数据,对智能车的运行状况实行实时监控,能在线修正运行参数,并为智能车控制算法的离线改进提供有效的依据。