High precision A/F control ECU for ultra low emission vehicles

High precision A/F electronic control, which is an application of modern control technology, has played a special role as a ULEV emissions reduction technology. Observer theory has been used to compensate for variations in the air/fuel ratio between cylinders, and self tuning regulators have been used to control transient conditions and disturbances. These innovations have led to improvements in control performance.In order to implement these controls, the CPU must be capable of high speed computation. Thus RISC microcomputers for automotive use, which provide high speed computation in a small chip size, have been developed to replace conventional CISC microcomputers. This RISC chip has been used in our ULEV control ECU to provide high precision A/F control.     

汽车电子稳定系统（ESP）结构及常见故障检修

随着现代汽车技术的发展,汽车的主动安全性已有着大大地提高。汽车电子稳定系统（简称ESP）便是一种新型汽车主动安全系统。它可实时监控汽车的行驶状态,在紧急躲避障碍物或转弯时出现转向不足或转向过度时,可使汽车避免偏离理想轨迹,从而减少交通事故。ESP系统大致由四大部分构成（如图1所示）：用于检测汽车状态和驾驶员操作的传感器部分、     

Model-based control of an electropneumatic brake system for commercial vehicles

A properly functioning brake system is critical for ensuring the safe operation of any vehicle on roadways. Commercial vehicles such as trucks, tractors-trailers and buses are equipped with an air brake system that uses compressed air as the energy transmitting medium. This paper presents a model-based control scheme for an electropneumatic brake system for use in commercial vehicles. A mathematical model for an electropneumatic brake system was developed and corroborated with experimental data. A control scheme was developed based on this model and was used to regulate the pressure of air inside the brake chamber according to a desired pressure trajectory. This control scheme was implemented on an experimental test bench, and its performance was studied for various values of the controller parameter. The control scheme was tested for various desired pressure trajectories reflecting actual brake operation.     

Robust yaw stability control for electric vehicles based on active front steering control through a steer-by-wire system

A robust yaw stability control design based on active front steering control is proposed for in-wheel-motored electric vehicles with a Steer-by-Wire (SbW) system. The proposed control system consists of an inner-loop controller (referred to in this paper as the steering angle-disturbance observer (SA-DOB), which rejects an input steering disturbance by feeding a compensation steering angle) and an outer-loop tracking controller (i.e., a PI-type tracking controller) to achieve control performance and stability. Because the model uncertainties, which include unmodeled high frequency dynamics and parameter variations, occur in a wide range of driving situations, a robust control design method is applied to the control system to simultaneously guarantee robust stability and robust performance of the control system. The proposed control algorithm was implemented in a CaSim model, which was designed to describe actual in-wheel-motored electric vehicles. The control performances of the proposed yaw stability control system are verified through computer simulations and experimental results using an experimental electric vehicle.     

山路行驶的柴油车污染物排放特性试验

在山路和平路上,进行了不同载荷下国V柴油车的实际道路行驶排放(RDE)试验.采集车速、海拔、氮氧化物(Nox)和颗粒物数量(PN)排放浓度等数据,分析了道路坡度、车辆载荷与输出功率对排放的影响.研究发现:测试柴油车辆,在平均坡度约6％山路行驶时Nox排放因子高于平路20％以上,PN低于平路20％以上.道路坡度自0增大到...     

Development of a new traction control system for vehicles with automatic transmissions

A traction control system (TCS) is used to improve the acceleration performance on slippery roads by preventing excessive wheel slip. In this paper, a new traction control system using the integrated control of gear shifting and throttle actuation is developed for vehicles with automatic transmissions. In the design of the slip controller, by means of a differential manifold transformation, a slip control system with nonlinearities and uncertainties is transformed into a linear system, and a sliding mode controller is applied for the purpose of increasing the robustness of the system. Next, to achieve the required driving torque, the optimal throttle and gear position, maps are constructed based on dynamic programming. The simulation results indicate that the present traction control system can improve the acceleration performance of an automatic transmission vehicle for various types of road conditions.     

轻型汽油车实际行驶污染物排放的影响因素

为了研究车辆冷起动、行程动力学参数和不同数据处理方法对实际行驶排放(RDE)试验的影响,本文利用4辆轻型汽油车进行试验研究,通过CO2移动平均窗口法和欧6新方法进行排放计算。结果表明:冷起动对CO和NOx排放影响偏差均在10%以内,对于未装配汽油机颗粒捕集器(GPF)车辆的市区PN排放影响偏差最大可达32.25%,在国6车型标定时应重点关注。相对正向加速度(RPA)与PN排放成正相关,与CO、NOx排放相关性不明显;v*apos,95(速度与正向加速度乘积按升序排序的第95个百分位取值)与CO、PN排放成正相关,与NOx排放成负相关,与CO和PN的相关系数大于与NOx的相关系数。对于同一个有效行程的污染物排放计算结果,欧6新方法大于CO2移动平均窗口法,欧6新方法能更加真实地反映车辆在RDE试验中的污染物排放水平。     

A semi-active control suspension system for railway vehicles with magnetorheological fluid dampers

The high-speed train has achieved great progress in the last decades. It is one of the most important modes of transportation between cities. With the rapid development of the high-speed train, its safety issue is paid much more attention than ever before. To improve the stability of the vehicle with high speed, extra dampers (i.e. anti-hunting damper) are used in the traditional bogies with passive suspension system. However, the curving performance of the vehicle is undermined due to the extra lateral force generated by the dampers. The active suspension systems proposed in the last decades attempt to solve the vehicle steering issue. However, the active suspension systems need extra actuators driven by electrical power or hydraulic power. There are some implementation and even safety issues which are not easy to be overcome. In this paper, an innovative semi-active controlled lateral suspension system for railway vehicles is proposed. Four magnetorheological fluid dampers are fixed to the primary suspension system of each bogie. They are controlled by online controllers for enhancing the running stability on the straight track line on the one hand and further improving the curving performance by controlling the damper force on the other hand. Two control strategies are proposed in the light of the pure rolling concept. The effectiveness of the proposed strategies is demonstrated by SIMPACK and Matlab co-simulation for a full railway vehicle with two conventional bogies.     

Application of rack type motor driven power steering control system for heavy vehicles

The Electric Power Steering (EPS) or Motor Driven Power Steering (MDPS) mechanism proves to be a bright prospect among passenger vehicles ensuring better vehicle safety and fuel economy. The car manufacturers are focusing on the production of Rack type EPS system (REPS). This paper describes the development of concurrent simulation technique using TruckSim and control strategy for analysing RMDPS control system with a dynamic vehicle system. A full Truck vehicle model interacting with RMDPS control algorithm was concurrently simulated on a sinusoidal steering input. The dynamic responses of vehicle chassis and steering system resulting were evaluated and compared with proving ground experimental data. The comparisons show reasonable agreement on steering wheel torque, lateral acceleration and yaw rate. This concurrent simulation research leads the possibility of RMDPS performance evaluation of Truck and Semi-bonnet cars.     

Development of a systematic and practical methodology for the design of vehicles semi-active suspension control system

In this paper, a novel systematic and practical methodology is presented for design of vehicle semi-active suspension systems. Typically, the semi-active control strategies developed to improve vehicle ride comfort and stability have a switching nature. This makes the design of the controlled suspension systems difficult and highly dependent on an extensive trial-and-error process. The proposed methodology maps the discontinuous control system model to a continuous linear region, where all the time and frequency design techniques, established in the conventional control system theory, can be applied. If the semi-active control system is designed to satisfy some ride and stability requirements, an inverse mapping offers the ultimate control law. At the end, the entire design procedure is summarised in six steps. The effectiveness of the proposed methodology in the design of a semi-active suspension system for a Cadillac SRX 2005 is demonstrated with road tests results. Real-time experiments confirm that the use of the newly developed systematic design method reduces the required time and effort in real industrial problems.     

Combined control of a regenerative braking and antilock braking system for hybrid electric vehicles

Most parallel hybrid electric vehicles (HEV) employ both a hydraulic braking system and a regenerative braking system to provide enhanced braking performance and energy regeneration. A new design of a combined braking control strategy (CBCS) is presented in this paper. The design is based on a new method of HEV braking torque distribution that makes the hydraulic braking system work together with the regenerative braking system. The control system meets the requirements of a vehicle longitudinal braking performance and gets more regenerative energy charge back to the battery. In the described system, a logic threshold control strategy (LTCS) is developed to adjust the hydraulic braking torque dynamically, and a fuzzy logic control strategy (FCS) is applied to adjust the regenerative braking torque dynamically. With the control strategy, the hydraulic braking system and the regenerative braking system work synchronously to assure high regenerative efficiency and good braking performance, even on roads with a low adhesion coefficient when emergency braking is required. The proposed braking control strategy is steady and effective, as demonstrated by the experiment and the simulation.     

军用电站运行监控系统设计

阐述了军用电站检测监控系统研制的必要性,介绍了系统的软、硬件设计方案,并详细介绍了系统的抗干扰设计。     

Electro-hydraulic braking system for autonomous vehicles

Reducing the number of traffic accidents is a declared target of most governments. Since dependence on driver reaction is the main cause of road accidents, it would be advisable to replace the human factor in some driving-related tasks with automated solutions. To automate a vehicle, it is necessary to control the actuators of a car, i.e., the steering wheel, accelerator, and brake. This paper presents the design and implementation of an electro-hydraulic braking system consisting of a pump and various valves, allowing the control computer to stop the car. It is assembled in conjunction with the original circuit for the sake of robustness and to permit the two systems to halt the car independently. This system was developed for installation in a commercial Citroën C3 Pluriel of the AUTOPIA program. Various tests were carried out to verify its correct operation, and an experiment showing the integration of the system into the longitudinal control of the car is described.     

Three-speed transmission system for purely electric vehicles

This paper discusses the necessity of using a transmission system to improve the energy efficiency of purely electric vehicles (EVs). The energy efficiency of an electric motor varies at different operating points to meet the output power demand. The three gear ratios of a transmission system can maintain the motor speed within a stable region with relatively high energy efficiency, while various vehicle speeds are needed. This work is based on a light EV prototype. The optimized gear ratios of this transmission result in a considerably reduced energy consumption of 9.3% compared with conventional EVs with single-speed reducers under the condition of the Urban Dynamometer Driving Schedule driving cycle. Thus, the transmission system is necessary to improve the energy efficiency of EVs.     

Full drive-by-wire dynamic control for four-wheel-steer all-wheel-drive vehicles

Most of the controllers introduced for four-wheel-steer (4WS) vehicles are derived with the assumption that the longitudinal speed of the vehicle is constant. However, in real applications, the longitudinal speed varies, and the longitudinal, lateral, and yaw dynamics are coupled. In this paper, the longitudinal dynamics of the vehicle as well as its lateral and yaw motions are controlled simultaneously. This way, the effect of driving/braking forces of the tires on the lateral and yaw motions of the vehicle are automatically included in the control laws. To address the dynamic parameter uncertainty of the vehicle, a chatter-free variable structure controller is introduced. Elimination of chatter is achieved by introducing a dynamically adaptive boundary layer thickness. It is shown via simulations that the proposed control approach performs more robustly than the controllers developed based on dynamic models, in which longitudinal speed is assumed to be constant, and only lateral speed and yaw rate are used as system states. Furthermore, this approach supports all-wheel-drive vehicles. Front-wheel-drive or rear-wheel-drive vehicles are also supported as special cases of an all-wheel-drive vehicle.     

电动汽车摩擦制动器的轻量化设计

本文主要对制动器的性能要求,在某一附着条件下所需的制动器制动力,在制动过程中的能量负荷及约束条件进行了描述,并运用遗传算法对摩擦制动器轻量化进行计算和设计     

四通道电液伺服汽车零部件试验计算机控制系统

就多通道电液伺服试验系统的计算机控制系统设计进行了研究，并取得实际应用。重点介绍了控制系统的配置、工作原理、功能和性能指标，具有良好的商业使用价值。     

关于控制重型汽车NO_x排放方法的研究

近年来随着我国汽车保有量与日俱增,汽车排放污染物已经成为一个非常严峻的问题。NOx是汽车排放污染物的重要组成部分,而重型汽车又是NOx的主要排放源,因此控制重型汽车NOx的排放具有重大现实意义。本文首先介绍了重型汽车主要污染物NOx的生成机理及其影响因素,随后对控制重型汽车NOX排放的EGR系统进行研究。