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1.
A dynamic model of a remotely operated vehicle(ROV) is developed. The hydrodynamic damping coefficients are estimated using a semi-predictive approach and computational fluid dynamic software ANSYS-CFX~(?) and WAMIT~(?). A sliding-mode controller(SMC) is then designed for the ROV model. The controller is subsequently robustified against modeling uncertainties,disturbances, and measurement errors. It is shown that when the system is subjected to bounded uncertainties, the SMC will preserve stability and tracking response. The paper ends with simulation results for a variety of conditions such as disturbances and parametric uncertainties.  相似文献   
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改善商用汽车主动和被动安全性的途径   总被引:1,自引:1,他引:1  
冯超 《汽车技术》1997,(11):1-8
重点介绍了改善商用汽车安全的途径,通过对交以爱事故的分析表明,为改善商用车的主动安全性,必须应用电子智能技术,如全电子控制制动动系统,电子控制的动力向,全电子控制传动系统和电子网络技术等。还介绍了加强被动安全性的措施,如防前钻保护装置等。  相似文献   
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This study presents a new method for calculating return values. The essence of the method is that it utilizes nonstationary data to calculate the return value for a region in the Northeast Pacific. The nonstationary data was obtained from a model which was previously developed for the behavior of the significant wave height as a function of time in the region. The method is illustrated by convolving two generalized Pareto distribution functions fitted to two parts of the model, computing a suitable extreme value from the new distribution function, and calculating the return value using this extreme value.  相似文献   
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Electric vehicle’s motor draws power from battery to meet its power demand in different road profiles. Battery high discharged currents are causes of warming battery’s cells. The temperature of 40 ºC and above reduces battery life span. The rationale of fuzzy controlled evaporative battery thermal management system (EC-BThMS) development from this study is to control the battery temperature in the range of 20 ~ 40 ºC both in charging/discharging modes. The proposed system has been developed with estimating the total cooling loads and thermal behavior of the battery cells. A fuzzy controlling system has been introduced with the EC-BThMS to control the electro-compressor and the expansion valve based on the response of battery temperature sensors.A battery pack of 8.6 kWh equipped EV has been operated with 60 km/h on 0 % gradient and 40 km/h on 5 % gradient in IIUM campus while 130 km/h on 0 % gradient and 50 km/h on 3.67 % gradient in Malaysia International Formula circuit to study the battery temperature profile and percentage of battery power saving. Comparison has been made on the performance of EC-BThMS with air cooling battery thermal management system (AC-BThMS) by using same vehicle. Result shows that EC-BThMS can save energy 17.69 % more than AC-BThM 1 and 23 % more than AC-BThM 2.  相似文献   
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The real-time simulation of vehicle trains requires an accurate and numerically feasible representation of the vehicle-trailer coupling. Although the equations of motion for the chassis instances can be reduced to systems of ordinary differential equations, additional constraints on the relative motion of vehicle and trailer are introduced when considering the hitch. In this article, we present a strategy for the simulation of vehicle-trailer combinations, where the algebraic constraints of the coupling are treated explicitly. Although this approach allows exact modeling of the respective joint geometry and realistic calculation of the coupling forces, a suitable numerical algorithm is required in order to solve the resulting differential-algebraic system of index 3 in real-time. The implementation in a commercial vehicle dynamics program is discussed and real-time simulation results are shown, which prove its feasibility for different coupling joints and demanding driving maneuvers.  相似文献   
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Long-term observations of the marine atmospheric boundary layer were performed by an eddy correlation system, which was set-up on a platform in the Baltic Sea. In this experiment the three-dimensional wind vector and the turbulent fluxes of momentum, sensible and latent heat and CO2 were measured for one and a half years. Simultaneously the CO2 partial pressure pCO2 in surface water was measured by a submersible autonomous moored instrument for CO2 at the platform in 7-m depth. The high-resolution eddy correlation measurements of the atmospheric CO2 flux FCO2, together with the measurements of the CO2 partial pressure differences between air and sea ΔpCO2 led to a long-term data set which provided the possibility to investigate the parameterization of the CO2 transfer velocity k as a function of 10-m wind speed u in a statistical manner. From half-hour mean CO2 fluxes and CO2 partial pressure differences, k was calculated using k = FCO2 / (K0ΔpCO2), with K0 the CO2 solubility. The half-hour mean data points, used for the determination of the ku parameterization, show large scatter. However, assuming a linear, quadratic dependency the analysis yields: k660 = 0.365u2 + 0.46u (k at 20 °C and salinity 35 psu) with a correlation coefficient of r2 = 0.81. The large scatter indicates that the kinetics of the air–sea CO2 transfer velocity is not only a function of the wind speed alone, but might also be controlled by other environmental parameters and mechanisms, such as sea state and surface coverage with surfactants.  相似文献   
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具有共轨式喷射系统的燃烧技术的新发展   总被引:1,自引:0,他引:1  
新型MTU 4000系列柴油机,采用了一种新的共轨式喷射系统。它克服了传统喷射系统的典型约束,即喷射压力与柴油机转速有关,本文提出了有关燃烧技术发展的新措施,并要求充分利用共轨式喷射系统的优点,利用柴油机整个特性场中可获得的高的喷射压喷孔的数量,还可以应用更浅的活塞顶面盆槽从而将改善空气在燃烧室中的分布,最终可以降低有害物的排放和燃油消耗率。  相似文献   
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Via a conventional steering system the driver perceives desired and disturbing effects such as road feedback and resonance effects, respectively. They appear with overlapping frequency spectra within the driver's steering torque. This paper introduces a control algorithm that is suppressing periodic disturbances without affecting useful steering road feedback attributes as well as regular power assistance characteristic. This is realised by an integrated torque actuator within the steering column in conjunction with a conventional Hydraulic-assisted Power Steering (HPS) system.  相似文献   
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