design of a closed loop control virtual test for vehicle handling stability

In an effort to address the high risks and qualification demands of test drivers, a vehicle model and a driver model were built based on ADAMS/CAR, an advanced block of ADAMS. The steering efforts test procedure was designed according to the national standard GB/T 6223.5—1994. A virtual test was performed in ADAMS, and the results calculated. The results show that the driver model possesses a strong capacity to charge the vehicle model. The virtual test results satisfy the evaluation index, indicating the virtual test can be used to test and improve vehicle performance.     

Vehicle stability control system design using optimal allocation of yaw moment

In order to improve vehicle handling stability,a control system using optimal allocation of yaw moment was designed.The first layer is a linear quadratic regulator (LQR) controller,which optimizes a desired yaw moment to work on the vehicle and calculates reference wheel slip for the target wheel.The second layer of the control system is a PID controller which can track the reference wheel slip rate,and then apply braking torque on the target wheel to make the vehicle stable.Simulations are carried out by using an 8-dof nonlinear vehicle model under different conditions.The simulation results indicate that the designed control system can effectively improve vehicle handling stability.     

Application of state feedback and observer inmulti-axle vehicle steering system

A 3-degrees of freedom multi-axle vehicle dynamic model is established.Taking account of the practical difficulties for measuring the sideslip,rolling angles and rolling angle speed,a Luenberger observer is designed,and the simulation and analysis of the Luenberger observer are performed.The results show that the Luenberger observer has excellent characteristics in the considered speed range in tracking path.Then,a state feedback controller is designed on the basis of the Luenberger observer,and simulation of a multi-axle vehicle is also carried out.The results show that the performances of a multi-axle vehicle with the proposed control strategy is better than a multi-axle vehicle with front wheel steering strategy,and its control system has fine dynamic characteristic and strong robustness,so multi-axle vehicle with the proposed control strategy can improve vehicle handling stability and security.     

Model predictive control strategy of a medium hybrid electric vehicle

The intense coupled and nonlinear behaviors were observed on the tall long span tower line systems which were under the icing and wind loads in heavy icing areas. A set of stiffness equations of insulator, conductor and boundary conditions was deduced. Taking the ±800 kV UHV DC transmission line from Xiangjiaba to Shanghai as an example, the simplified numerical model of transmission tower, conductor, insulator and constraint was developed. The long span transmission tower line system models under seven loads conditions were analyzed by static nonlinear methods. It was found that the P Δ effect of tower components was small when the covered ice was uniformly distributed. The unbalanced wire loads on the tower would lead to twist effect when the covered ice was uneven distributed. The axial forces, moments at restraint nodes and the longest cantilever member were greatly affected by the P Δ effect, under which the unfavorable effect on the structure should be considered.     

Coordinated pressure control of a regenerative braking system based on a hybrid electric vehicle with an integrated startor and generator

With a focus on a Changan hybrid electric vehicle (HEV) with an integrated startor and generator (ISG), strategies for braking force distribution and coordinated pressure control are put forward, and a dynamic braking control model is constructed for off     

Dynamic scheduling method of vehicle air-conditioning assembly shop based on feedback control

By analyzing the inherent uncertainties, discrete uncertainties and external environmental uncertainties, a dual-feedback control strategy and the dynamic scheduling method are proposed to solve the dynamic scheduling problem of vehicle air-conditioning assembly shop under uncertainty. Considering the reentrant constraint, equipment capacity constraint, and time discrete constraint etc., the multi-objective scheduling model of vehicle air-conditioning assembly shop is set up,taken the earliness/tardiness, process time, production cost and quality loss as optimization objectives. According to the characteristic of the model, sectional chromosome encoding, crossover operator and mutation operator are designed to prevent the generation of illegal solutions and improve efficiency of the algorithm. An example is given to prove the feasibility and validity of the approach.     

RS UM based information system security assurance evaluation model

Based on the information system security assurance evaluation framework (GB/T20274),the information system security assurance model and evaluation index system are introduced, and the formalization evaluation method and flow are presented. An information security evaluation model is proposed by applying rough set (RS) and unascertained measure (UM) theory. At the criterion pre process period, rough set theory is used to obtain the key evaluation indexes and construct the reduced index set to simplify the original complex index system. At the evaluation period, unascertained measure model is adopted to analyze the evaluation data to implement a quantitative integration evaluation on the information system security assurance ability.     

利用前列腺癌细胞株比较各种茄红素的传送载体对茄红素的稳定性及吸收效果

许多研究指出摄取富含茄红素的食物具有降低多种癌症的发生率,如前列腺癌、肺癌等[1,2]。在茄红素体外试验中,最常使用四氢呋喃(tetrahydrofuran;THF)作为溶剂,但THF结构不稳定,极易氧化,且具有细胞毒性,因此易造成茄红素体外试验之干扰[3￣5]。本实验拟使用胎牛血清(fetalbovineserum;FBS)作为载体,我们认为FBS中的脂蛋白(lipoprotein)可以增加茄红素稳定性并促进细胞的吸收效果。     

The study on EMI principle and suppression method of vehicle ignition system

Vehicle ignition system is the main electromagnetic interference source. Electromagnetic radiation produced by ignition system will produce the interference to electromagnetic environment around. It is necessary to study the electromagnetic interference (EMI) principle, noise paths and suppression method. We analyze the electromagnetic interference principle of ignition system, and harness trouble-shooting related to electromagnetic interference is also tested. Results show that the spark discharge between spark plug electrodes is the main interference source in ignition system. Then, the paths of conducted interference and the reason of radiated emission are discussed in detail. Finally, two kinds of power supply cord EMI filters are designed and implemented on the basis of analysis results. Experimental results indicate that the filter can reduce the noise of power-wire in broadband range. Simultaneously, the radiation emission performance from power wire is also reduced observably. The proposed mixing filter has been demonstrated in this paper to perform satisfactorily with excellent effectiveness in suppression of conducted EMI from 10 MHz to 110 MHz, and the object car can also pass the EMC standard tests.     

The predictive control of an incremental model based on tracking error

An algorithm of incremental model predictive control is proposed to solve a class of industrial production process real-time tracking problems. The basic idea is to establish a predictive model by adopting speed response on the basis of tracking error, and realize the optimization of the second time performance by using the soft constraint of the increment of control quantity and the online rolling optimization method. The theoretical analysis and Matlab simulation results show that the control algorithm can obtain good tracking performance, smooth dynamic response of the controlled object and strong robustness of the closed-loop system.     

Control strategy of regenerative braking for hybrid electric vehicle based on engine braking

Focusing on a continuously variable transmission(CVT) hybrid electric vehicle with integrate starter generator(ISG), modeling and simulating of engine braking was conducted. An optical control strategy of regenerative braking was put forward. When there is no regenerative braking, engine brake force can be used effectively by changing the CVT ratio to reduce the braking force requirements for wheel brakes based on the calculated results of engine braking. When there is regenerative braking, the braking priority sequence is generator braking, engine braking, and finally frictional braking. A forward simulation model for regenerative braking system of hybrid electric vehicle was built. The simulation and analysis under typical driving cycles was conducted. The result shows the control strategy and the models are reasonable and feasible.     

基于LS-SVM逆系统的焦炉集气管压力系统内模控制

焦炉集气管压力是炼焦生产过程中重要的工艺参数,其值是否稳定,直接影响到煤气质量、焦炉寿命、焦炭质量和生产环境。针对焦炉集气管压力系统是一个强干扰、非线性和多变量耦合的复杂系统,采用LS-SVM辨识出焦炉集气管压力系统的逆系统模型,并将其串联在原系统之前,运用逆系统的方法将集气管压力系统解耦成2个相互独立的单输入单输出伪线性子系统。同时,对解耦后的系统采用非线性内模控制策略以保证系统的鲁棒性和稳定性。仿真和应用结果表明该控制策略的解耦控制效果较好,提高了系统的快速调节能力和跟踪精度,而且增强了系统的鲁棒性,可以保证焦炉集气管压力稳定在现场工艺要求的范围内。     

Research and development of a testing control system for a heavy duty vehicle automatic mechanical transmission test bench

Automatic mechanical transmissions (AMT) are suitable for use in heavy duty vehicles. Bench testing is an important task of the research and development. Many objectives, such as AMT performance testing, matching AMTs with engines, and optimizing control rules, can be achieved through bench testing, thereby laying a foundation for AMT application. An AMT testing bench is built up based on a developed AMT. By analyzing the performance requirements of AMT bench testing for heavy duty vehicles, a testing controlling system scheme is proposed and methods of data acquisition and communication are analyzed. Control methods for actuators are proposed based on analyzing the characteristics of AMT actuators. A testing control program for AMT bench testing is developed based on the Delphi platform. The entire bench testing system possesses advances test functions.     

球团矿还原的动力学模型分析

基于还原炉控温还原实验,通过分析CO和H2还原球团矿过程中的反应速率模型,提出两种气体混合后还原球团矿的反应动力学模型,得到还原过程中阻力和反应速率随温度及还原度的变化规律,得出结论：CO还原球团矿时,内扩散阻力所占比例随着温度及还原度增加而变大;H2还原球团矿时,内扩散属于速率控制环节;混合气还原球团矿时,反应速率随温度升高而增大,温度低于500 ℃时,CO浓度增加,反应速率降低,而温度超过500 ℃后,反应速率则随着CO浓度的增加而增大;混合气反应速率模型的计算值与实验结果一致。     

An illuminance ratio model based on a luminance transfer function matrix

An illuminance ratio model of both single and multiple sources was proposed. The model tried to compensate for a lighting dimming system acting incorrectly as a result of an illuminance sensor aimed at a workplace sheltered by paper or a human body. The method was based on a luminance transfer function matrix, and the model parameters were estimated via the least squares method. Simulated and experimental results show the illuminance calculated using the model is consistent with the actual situation. The illuminance sensor setting based on this model can not only reduce difficulties associated with laying lines, but also avoid incorrect action caused by the illuminance sensor aimed at a workplace sheltered by paper or a human body. This research serves as a reference for the design of lighting dimming systems.     

Safety evaluation of hazards based on discrete Hopfield neural network

In order to evaluate hazard’s level efficiently and decrease disasters’ influence on the surrounding environment,a safety evaluation index system of hazards is set up first by considering influence factors of personnel,equipment,raw material,technology,and environment. Then,a hazards safety evaluation model is built by combining neural network with safety system engineering theory. Finally,case studies testify the model can evaluate the hazards’ level reasonably and objectively.     

基于内聚力模型的锈蚀砼梁抗弯刚度

粘结性能退化是导致锈蚀钢筋混凝土构件力学性能下降的主要因素之一,基于锈蚀构件粘结性能实验研究成果与内聚力模型,建立了有厚度的双线性内聚力单元与分离式钢筋混凝土梁分析模型,引入粘结界面层,研究了粘结性能退化对锈蚀钢筋混凝土梁抗弯刚度的影响。结果表明,双线性内聚力单元可以有效模拟钢筋与混凝土之间的粘结机制,而根据锈蚀深度确定的有厚度的粘结单元能合理描述锈蚀程度对粘结性能的影响。数值分析结果与实验及经验公式对比,表明了文中方法的有效性和合理性。     

大体积混凝土BIM智能温控系统的研究与应用

回顾并分析了2015年我国蒜薹产业的经营情况,预测2016年全国蒜薹产业的前景,并提出蒜薹产业新时期面临的新挑战,旨在为稳健科学地应对2016年我国蒜薹产业的发展提供有益的参考借鉴。     

The method of dynamic aperture control technology based on ultrasound imaging system

Dynamic aperture control technology is one of the most important parts in ultrasonic imaging system. Excellent control technology of dynamic aperture can effectively improve the quality of ultrasonic imaging. Based on deep analysis of ultrasonic beam distribution, a control method for dynamic aperture which can eliminate the scanning dead zone of focused beam is presented. The detection region is even divided according to the number of probe array elements. The desired focused beam width is calculated between the next two scan lines at different depths, and then according to the beam width, the required aperture size for different depths is determined. The method is not affected by the probe parameters or detection objects, and it can be widely employed in ultrasonic imaging system. The simulation experiments indicate that the proposed method can effectively improve the whole quality of ultrasonic imaging.