Almost disturbance decoupling control of mimo nonlinear system subject to feedback linearization and a feedforward neural network: Application to half-car active suspension system

A novel tracking and almost disturbance decoupling problem of multi-input, multi-output (MIMO) nonlinear systems based on feedback linearization and a multi-layered feedforward neural network approach has been proposed. The feedback linearization and neural network controller guarantees exponentially global uniform ultimate bounded stability and almost disturbance decoupling performance without using any learning or adaptive algorithms. The new approach renders the system to be stable with the almost disturbance decoupling property at each step when selecting weights to enhance the performance if the proposed sufficient conditions are maintained. One example, which cannot be solved by the existing approach of the almost disturbance decoupling problem because it requires the sufficient conditions that the nonlinearities that multiply the disturbances satisfy structural triangular conditions, is proposed to exploit the fact that the tracking and the almost disturbance decoupling performances are easily achieved by the proposed approach. In order to demonstrate the practical applicability, a famous half-car active suspension system is investigated.     

展望中国Telematics业务发展

中国汽车生产商们首先必须了解,哪些是消费者愿意花钱购买的Telematics服务,一味地模仿西方市场,是不够的。     

Experiments on knocking and abnormal combustion through optical diagnostics in a boosted spark ignition port fuel injection engine

In this paper, flame front propagation during normal and abnormal combustion was investigated. Cycle-resolved flame emission imaging was applied in the combustion chamber of a port fuel injection-boosted spark ignition engine. The engine was fueled with a mixture of 90% iso-octane and 10% n-heptane by volume (Primary Reference Fuel 90: PRF90) and commercial gasoline. The combustion process was monitored from the flame kernel formation until the exhaust valves opened. Different phenomena associated with abnormal combustion were analyzed, including the fuel deposition burning. Moreover, the ignition surfaces and end-gas auto-ignitions were investigated in terms of timing, location and frequency of occurrence. The analysis was performed by considering different knocking intensities for both the selected fuels.     

Valuing road noise for residents in Hong Kong

This study estimates the willingness-to-pay value for a one dB(A) change over a range of initial noise levels for a sample population in Hong Kong. It establishes a protocol for estimating the willingness-to-pay values by first establishing an annoyance–dB relationship. The protocol takes into account the characteristics that the probability of being annoyed at a particular level varied with the initial objective noise level, and the annoyance–dB relationship varied for a range of initial annoyance level. The study shows that household income level and initial annoyance levels exert considerable influences on the individual’s willingness-to-pay values. However, age and educational level were found not to exert any significant influence on individual’s willingness-to-pay values.     

Intérêt du modèle ? Hurdle ? pour la comparaison des comportements de mobilité déclarée dans un protocole d’enquête mixte

Due to decline in response rate to household travel surveys, it is essential that survey methods research explore the use of mixed-mode surveys. With this in mind, the Laboratoire d??économie des transports (Transport Economics Laboratory) conducted a web-based survey on non-respondents to a face-to-face household travel survey administered in the Lyon urban area in 2005?C2006. Comparative analysis of the figures shows that, overall, face-to-face respondents travel more than web-based respondents. This difference is partly explained by a high proportion of individuals who did not travel on the survey reference day and also by a lower trip level for those who travel. Classical regression methods can explain the individual mobility level with individuals socioeconomic characteristics, but do not take account of individuals who did not travel during the survey reference period. Using two econometric methods (simple Poisson and Hurdle Poisson regression) we examined factors affecting the decision to travel on one hand and the level of mobility on the other hand. This involves estimating the average daily mobility of individuals as a function of their socioeconomic characteristics while taking into account the fact that for a considerable part of the survey population, daily mobility is nil. Our approach intends firstly to define the causes of immobility better and secondly to characterise the mobility level with the help of a Hurdle model, so as to compare the results obtained in the web-based and faceto-face samples.     

碧海之上 挑衅骄阳 航海防晒攻略

夏季是乘风破浪的最佳季节，热爱冒险刺激的你渴望出海扬帆，注重生活品质的你又需要保护好皮肤——航海防晒，就成为了航行之前，你不可不做的”功课”。只需要一点点时间和心思，将以下7点身体力行，你就可以尽享在碧波蓝天下，驯服烈日的快乐。     

Effects of closed trawl fishery areas on some elasmobranch species in the Cantabrian Sea

This study examines the effects of certain closed areas to the trawl fishery on some Rajidae species and small-spotted catshark in the southern area of the Bay of Biscay. The results are based on abundance index (number/haul) and catch length composition obtained from a series of bottom trawl surveys carried out in the area (1993–2005). Abundance trends are similar considering or not closed areas, but with much lower values excluding closed areas. The length distributions revealed that in some of the species like Scyliorhinus canicula the larger specimens were the most affected by this decrease in number. Finally, the effects and consequences of one of these marine protected areas (MPAs), an artificial reef were examined in more detail for all the fishes and invertebrates. The analysis of the yield series showed an increase in total biomass after the placement of the reefs not only for S. canicula and rays but also teleosts fishes like Pagellus acarne, Trachurus trachurus, Mullus surmuletus and Trachinus draco and particularly invertebrates (sea urchins). On the contrary, the main target species of the trawl fishery (hake, monkfish and megrim among others) did not increase.     

哪种航速能提供最佳经济效益？

最近,不断上涨的燃料价格致使人们更积极地探索减少货船燃耗的方法.诸多可能方法中,德国劳氏船级社研究了合理减小航速对集装箱船队的影响.研究结果表明,根据对未来船舶推进成本的预测,使用比目前低的航速能为集装箱船队带来经济利益.     

Assessment of the influence of different cooling system configurations on engine warm-up, emissions and fuel consumption

One of the major goals of engine designers is the reduction of fuel consumption and pollutant emissions while keeping or even improving engine performance. In recent years, different technical issues have been investigated and incorporated into internal combustion engines in order to fulfill these requirements. Most are related to the combustion process since it is responsible for both fuel consumption and pollutant emissions. Additionally, the most critical operating points for an engine are both the starting and the warming up periods (the time the engine takes to reach its nominal temperature, generally between 80°C and 90°C), since at these points fuel consumption and pollutant emissions are larger than at any other points. Thus, reducing the warm-up period can be crucial to fulfill new demands and regulations. This period depends strongly on the engine cooling system and the different strategies used to control and regulate coolant flow and temperature. In the present work, the influences of different engine cooling system configurations on the warm-up period of a Diesel engine are studied. The first part of the work focuses on the modeling of a baseline engine cooling system and the tests performed to adjust and validate the model. Once the model was validated, different modifications of the engine coolant system were simulated. From the modelled results, the most favourable condition was selected in order to check on the test bench the reduction achieved in engine warm-up time and to quantify the benefits obtained in terms of engine fuel consumption and pollutant emissions under the New European Driving Cycle (NEDC). The results show that one of the selected configurations reduced the warm-up period by approximately 159 s when compared with the baseline configuration. As a consequence, important reductions in fuel consumption and pollutant emissions (HC and CO) were obtained. On doctoral leave from Universidad Technológica de Pereira (Colombia)