Vehicle Dynamics Estimation Using Kalman Filters

This paper deals with the application of stochastic state estimators in vehicle dynamics control. It is often unrealistic to assume that all vehicle states and the disturbances acting on it can be measured. System states that cannot be measured directly, can be estimated by a Kalman Filter. The idea of the Kalman filter is to implement a model of the real system in an on-board computer in parallel with the system itself. This paper will give 3 examples of this principle applied to automotive systems.     

Deterring the dauntless—appraising the effects of naval deterrence against the Somali piracy

This article considers whether the Somali pirates were deterred by the naval task forces between the years 2009 and 2013. By disaggregating data and using previously unpublished records regarding the naval operations, two areas of operations are identified as potential periods of deterrence. The article uses a model of asymmetric deterrence to study the outcomes and equilibria of the navy-pirate interaction. It is found that the naval operations eventually did deter the Somali pirates in the Gulf of Aden, but that this objective was not met in the Somali Basin. It is concluded that the operational focus on the Gulf of Aden coupled with the fact that the area is relatively smaller than the Somali Basin enabled the naval credibility, thus effectively denying the pirates access to the sea. Conversely, limited attention by the naval units and the long Somali southern coast with its open waters impeded naval control in the Somali Basin. In connection to these findings some conclusions regarding naval deterrence are discussed.     

An energy‐mobility beach classification system as a basis for the management of beach resources

Abstract

The successful implementation of structural and nonstructural solution to problems of shoreline erosion is greatly facilitated if the accumulation and analysis of data sets are accomplished within a design framework which has both theoretical validity and practical application. An inventory of beach resources based upon breaking‐wave energy and beach mobility is presented as a basis for a beach classification system. This method should be used with existing inventories compiled by the U.S. Army Corps of Engineers. A simplified means of determining changes in beach position and slope is suggested; this will facilitate gathering data in a daily time series at numerous locations by a minimum number of people. Examples of how the inventories may be conducted and a sample classification system are presented for selected portions of the shoreline of New Jersey.     

制动盘的定期维护

维修技师掌握一些汽车定期预防性维护的技能,能够为维修厂以及其顾客带来许多潜在的经济效益。 一些聪明的维修厂老板会大力加强汽车维修厂在定期预防性维护方面的业务能力,以努力提高客户车辆的可靠性;另外,这些维修厂还会耐心地向车主解释进行车辆定期维护能够给他们带来许多具体的好处的,然后给车主制定一个定期养护时间     

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.     

The analysis of motor vehicle crash clusters using the vector quantization technique

In this paper, a powerful tool for analyzing motor vehicle data based on the vector quantization (VQ) technique is demonstrated. The technique uses an approximation of a probability density function for a stochastic vector without assuming an “a priori” distribution. A self‐organizing map (SOM) is used to transform accident data from an N‐dimensional space into a two‐dimensional plane. The SOM retains all the original data yet provides an effective visual tool for describing patterns such as the frequency at which a particular category of events occurs. This enables new relationships to be identified. Accident data from three cities in Italy (Turin, Milan, and Legnano) are used to illustrate the usefulness of the technique. Crashes are aggregated and clustered crashes by type, severity, and along other dimensions. The paper includes discussion as to how this method can be utilized to further improve safety analysis. Copyright © 2010 John Wiley & Sons, Ltd.     

钱学森的现代科学技术体系与综合集成方法论 — 祝贺钱学森院士九十华诞

介绍了钱学森提出的现代科学技术体系和综合集成方法论.现代科学技术体系是由横 向11个科学技术部门和纵向三个层次所构成的矩阵式结构;综合集成方法论是由“从定性到定 量综合集成方法”和“从定性到定量综合集成研讨厅体系”,所构成。文章还讨论了它们在实践中的应用.