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Viewing 1 to 30 of 19927
2017-10-08
Technical Paper
2017-01-2268
Zhanming Chen, Long Wang, Tiancong Zhang, Qimeng Duan, Ke Zeng
Liquefied natural gas (LNG) fuelled engines have been widely equipped on heavy duty vehicles both for fuel-economic and environmental protection concerns, however, they always suffer from deteriorated combustion performance and flame stability due to relatively low burning velocity of methane for lean mixture. In this paper, experimental study was conducted on a turbo-charged, spark-ignition, lean-burn LNG engine with methanol port injection. The combustion characteristics such as cylinder pressure traces, heat release rate (HRR), mass fraction burned (MFB), ignition delay, centroid of heat release, position of CA50 and CA90, as well as cyclic variation of peak pressure were analysed under light load (BMEP=0.3876MPa) with different methanol substitution rates (MSR=0%, 5.2%, 10.2%, 17.2%). The experimental results show that combustion phase advanced with increment of MSR due to faster burning velocity of methanol.
2017-09-23
Technical Paper
2017-01-1953
Manfei Bai, Lu Xiong, Zhiqiang Fu, Renxie Zhang
Abstract: In this paper, a speed tracking controller is designed for the All-terrain vehicles. The method of feedforward with state variable feedback based on conditional integrators is adopted by the proposed control algorithm. The feedforward is designed considering the influence of the road slope on the longitudinal dynamics, which makes the All-terrain vehicles satisfy the acceleration demand of the upper controller when it tracks the desired speed on the road with slope varying greatly. The road slope is estimated based on a combined kinematic and dynamic model. This method solves the problem that road slope estimation require an accurate vehicle dynamic model and are susceptible to acceleration sensor bias. Based on the vehicle dynamic model and the nonlinear tire model, the method of conditional integration is used in the state variable feedback, which considers the saturation constraint of the actuator with the intention of preventing the divergent integral operation.
2017-09-23
Technical Paper
2017-01-1954
Peng Hang, Xinbo Chen, Fengmei Luo
Path tracking is the rudimentary capability and primary task for autonomous ground vehicles (AGVs). In this paper, a novel four-wheel-independent-steering (4WIS) and four-wheel-independent-drive (4WID) electric vehicle (EV) is proposed which is equipped with steer-by-wire (SBW) system. Compared with conventional front-wheel-steering (FWS) vehicles, 4WIS and 4WID EV has superior maneuverability, handing stability and path-tracking capability thanks to more actuators. Therefore, it is more suitable for a desired AGV. For path-tracking controller design, the nonlinear vehicle model with 2 degrees of freedom (DoF) is built utilizing the nonlinear Dugoff tire model. The nonlinear dynamic model of SBW system is conducted as well considering the external disturbances.
2017-09-23
Technical Paper
2017-01-1958
Motion Planning of Automatic Driving in Complex Traffic Scenarios With the increasing complexity, dynamicity and uncertainty of traffic, motion planning of automatic driving is getting more difficult and challenging. This paper focuses on the real-time motion planning problem of connected and automated vehicles in complex traffic scenarios. To effectively solve this problem, a general driving risk model is presented, which contains the following two essential parts: i) collision risk, i.e., the collision risk between the subject vehicle and other surrounding vehicles, pedestrians, buildings etc.; ii) non-collision risk, such as violation of traffic regulations, the difference between the actual operation state of the subject vehicle and the intention of driver, etc. In order to achieve the real time collision detection, the subject vehicle is approximated to a dot and its shape is considered by extending the dimension of obstcales considering their relative position and velocity.
2017-09-23
Technical Paper
2017-01-1955
Yandong Ruan, Hui Chen, Jiancong Li
An integrated automatic driving system consists of perception, planning and control. As one of the key component of autonomous driving system, the longitudinal planning module guides the vehicle to accelerate or decelerate automatically on the roads. A complete longitudinal planning module is supposed to consider the flexibility to various scenarios and multi-objective optimization including safety, comfort and economy. However, most of the current longitudinal planning methods can not meet all the requirements above. In order to satisfy the demands mentioned above, a new Potential Field (PF) based longitudinal planning method is presented in this paper. Firstly, a PF model is constructed to depict the potential risk of surrounding traffic entities, including obstacles and roads. The shape of each potential field is closely related to the property of the corresponding traffic entity.
2017-09-23
Technical Paper
2017-01-1959
Bin Li
A new anti-slip regulation algorithm adaptive to road slope is proposed for intelligent vehicles. The controller based on sliding mode control is robust to wheel parameter uncertainty. The longitudinal velocity estimator based on the integration of dynamic method and kinematic method is adopted to reduce the velocity estimation error. By putting wheel deceleration information into use, the kinematic estimator is able to estimate slip when the wheel is skidding, so the estimation accuracy is improved. In additional, an integration algorithm of four wheel velocity estimations is used to improve the estimation accuracy. The road slope is estimated online using recursive least square with forgetting factor in rampway and the longitudinal acceleration sensor information is calibrated by the slope estimation value for slope adaptive longitudinal velocity estimation.
2017-09-23
Technical Paper
2017-01-1960
Xiaopeng Zong, Guoyan Xu, Guizhen Yu, Hongjie Su, Chaowei Hu
Obstacle avoidance is an important function in self-driving vehicle control. When the vehicle move from any arbitrary start positions to any target positions in environment, a proper path must avoid both static obstacles and moving obstacles of arbitrary shape. There are many possible scenarios, manually tackling all possible cases will likely yield a too simplistic policy. In this paper we apply reinforcement learning to the problem of forming effective strategies. We note that there are two major challenges that make self-driving vehicle different from other robotic tasks. First, in order to control the vehicle precisely, the action space must be continuous which means that traditional Q-learning can’t deal with. Second, self-driving vehicle must satisfy various constraints including vehicle dynamics constraints and traffic rules constraints. We make three contributions in our work.
2017-09-23
Technical Paper
2017-01-1962
Hongluo Li, Yutao Luo
With the rapid development of science and technology, intelligent electric vehicle (IEV) has gradually become the research focus to the scholars. The planning of the trajectory and the accurate path tracking ability are the two key technologies to realize the intelligent driving objective. This paper is conducted in this field that related research about intelligent drive to study the optimal steering wheel angle input.This paper proposes a method that dynamically plans the trajectory, not only to achieve quick reaction to the changing driving environment, but also to optimize the balance between vehicle performance and driving efficiency. First of all, the lane changing trajectory was planned based on the positive and negative trapezoidal lateral acceleration method, synchronously, the multi-objective optimization function was built which comprehensive such indexes: lateral acceleration/ lateral acceleration rate/ yaw rate/lane changing time and lane changing distance.
2017-09-23
Technical Paper
2017-01-1967
Wei Liu, Huan Tian, Jun Hu, Shuai Cheng, Huai Yuan
Image segmentation is critical in autonomous driving field. It can reveal essential clues such as objects’ shape or boundary information. The information, moreover, can be leveraged as input information of other tasks: vehicle detection, for example, or vehicle trajectory prediction. SegNet, one deep learning based segmentation model proposed by Cambridge, has been a public baseline for scene perceptron tasks. It, however, suffers an accuracy deficiency in objects marginal area. Segmentation of the area can be seen as the most difficult one compared with others. To alleviate the problem, in this paper, we propose one edge enhanced deep learning based model. Specifically, we first introduced one simple, yet effective Artificial Interfering Mechanism (AIM) which feeds segmentation model manual extracted key features. We argue this mechanism possesses the ability to enhance essential features extraction and hence, ameliorate the model performance.
2017-09-23
Technical Paper
2017-01-1978
Yuxiang Feng, Simon Pickering, Edward Chappell, Pejman iravani PhD, Chris Brace
The major contribution of this paper is to propose a low-cost accurate distance estimation approach. It is the first step of a research program aiming to model driving style variance. This paper proposes to fuse long range radar and monocular camera using Kalman filter, and can potentially be used in driver modelling, accident avoidance and autonomous driving. Based on MATLAB and Python, sensory data from a Continental radar and a monocular dashcam were fused using Kalman filter. Both sensors were mounted on a VW Sharan, performing repeated driving on a same route. The established system consists of three components, radar data processing, camera data processing and data fusion using Kalman filter. For radar data processing, raw radar measurements were directly collected from a data logger and analyzed using a Python program. Valid data were extracted and time stamped for further use. Meanwhile, a Nextbase monocular dashcam was used to record corresponding traffic scenarios.
2017-09-23
Technical Paper
2017-01-1989
Yi Chen, Gaoxiang Lin, Ying He
Intelligent and Connected Vehicles ( ICV) is a new generation of vehicles equipped with advanced sensors,controllers and actuators,and integrated with modern communication and network technologies. It can realize intelligent information exchange and sharing between vehicle and X(X——pedestrian,vehicle,road,background, etc.), with the functionalities of environment sensing,intelligent decision-making and cooperative control.It is safer,cleaner and smarter,and finally can replace the human driver.ICV becomes hotspot all around the world and it is highly concerned by Chinese government. National projects(e.g.,“13th Five Year Plan”and “Made in China 2025”) have paid a lot attention to the development of ICV. China's Ministry of Industry and Information Technology has established a demonstration area of ICV in Shanghai,thus Shanghai became the first pilot city of intelligent vehicle and autonomous driving.
2017-09-23
Technical Paper
2017-01-2010
Junfeng Yang, Michael Ward, Jahangir Akhtar‎
The INSIGHT project aims to develop driverless shuttles with advanced sensors and control systems for testing pedestrian areas with a focus on improving urban accessibility for disabled and visually-impaired people. The project activities require a safety case to provide guidance to identify and classify hazardous events, and avoid these risks by providing appropriate requirements and processes. The safety approach complying with requirements in ISO 26262 has been employed to generate series of hazardous events, safety goals and functional safety requirements in the vehicle level throughout the entire development lifecycle process. The technical focus of this study is on navigation system, human-machine interaction system and vehicle motion control system, e.g. steering, propulsion, suspension and brake. The malfunctioning behaviour of these system has been assessed, and their safety with layers of protection are produced based on the present method.
2017-09-23
Technical Paper
2017-01-2011
Suyash Singh, Ankur Mathur, Sandeep Das, Purnendu Sinha, Vinay Singh
In the Smart Cities, main objective is to promote cities that provide core infrastructure and give a decent quality of life to its citizens, a clean and sustainable environment and application of ‘Smart’ Solutions. The process said for utilization of available resources is the best fit for our concept. Our Concept is to convert and refurbish the old and scrap vehicles which will also increase their longevity and can be used in any smart city in India or abroad. The ultimate aim to provide this technology for the development of any new smart city in India is the utilization of available resources and reduction in the junk materials and environmental pollution. Refurbishing the old and scrap vehicles with replacement of IC engines doesn’t mean that they will be kept as a scrap and be thrown away, our idea is to utilize maximum of all the available resources. The IC engines taken out of these vehicles will be re-used appropriately.
2017-09-23
Technical Paper
2017-01-1977
Xin Bi, Bin Tan, Zhijun Xu, Libo Huang
The sensing technology of vehicle is the primary problem for advanced driver assistant system(ADAS) and autonomous driving functions. The fusion of millimeter wave radar and camera is an important trend to enhance the environmental perception performance. Converting the multiple target parameters (such as distance, velocity, angle, etc.) detected by radar sensor into the corresponding image coordinates is the key of fusion algorithm processing, as well as a difficulty. This paper presents a method in order to detect and classify the on-road obstacles, like cars or not cars (other obstacles),faster and more accurately.
2017-09-19
Technical Paper
2017-01-2062
Tushar Choudhary, Mithilesh Sahu, Shreya KRISHNA
Solid oxide fuel cell (SOFC) is the most promising candidate for utilization of waste generated from the GT based power system. By coupling SOFC with gas turbine (GT) based power system, a hybrid SOFC–GT power system has been developed and the thermal efficiency of the system can be enhanced upto 70-85%. This paper focuses of thermodynamic analysis of an internal reformed solid oxide fuel cell which is integrated with the gas turbine cycle to form a hybrid power generation system for an unmanned aerial vehicle (UAV) with a long range. Thermodynamic 1st and 2nd law, parametric analysis has been carried out and the effect of various parameters such as compressor pressure ratio, turbine inlet temperature, air flow rate has been examined. In order to validate the results, present work has been compared with the available literature and it shows good agreement.
2017-09-19
Technical Paper
2017-01-2064
Parvez Alam M, Dinesh Manoharan, Satheesh Chandramohan, Sabarish Chakkath, Sunil MAURYA
In the present market, multiple sophisticate and expensive Thrust Test Rigs for Brushless Motors (BLDC Motor) are available making it impossible to conduct such thrust analysis on a regular and cost effective basis. Moreover the present test rigs are incapable to measure high Thrust values. This needs specialized thrust testing rig which is more expensive. This paper aims at Design & Development of the Small Scale Test Rig Setup for measurement of the thrust of any Brushless DC motor and helps in refining the Selection of motor and propeller. This is a set up based on cost efficiency factor to implement such rigs, test and for comparing the static thrust produced by the BLDC motor. The fairly simple construction contains a weighing machine, a Tachometer and a Wattmeter to measure the Thrust, RPM and the Current Drawn respectively, and provide comprehensive, accurate and efficient data coming from the BLDC Motor including the Propeller and Electronic Speed Control (ESC).
2017-09-19
Technical Paper
2017-01-2018
Won Il Jung, Larry Lowe, Luis Rabelo, Gene Lee, Ojeong Kwon
Operator training using a real weapon in a real-world environment is risky, expensive, time-consuming, and restricted to the given environment. The simulator, or a virtual simulation, is usually employed to solve these limitations. As the operator is trained to maximize weapon effectiveness, the effectiveness-focused training can be completed. However, the training was completed in limited scenarios without guidelines to optimize the weapon effectiveness for an individual operator, thus the training will not be effective with a bias. For overcoming this problem, we suggest a methodology on guiding effectiveness-focused training of the weapon operator using big data and Virtual and Constructive (VC) simulations. Big data, which includes structured, unstructured, and semi-structured types, are generated by VC simulations under a variety of scenarios.
2017-09-19
Technical Paper
2017-01-2020
Michael Croegaert
Modern military aircraft platforms are using more and more power which results in an ever increasing power density (SWaP). This in turn, generates more heat that has to be dissipated from the instrument panel and cockpit of the aircraft. Complicating this further is that the use of structural composites which are not efficient conductors of heat and the mission requirements of small heat signatures. Therefore alternative means of extracting the heat from the avionics systems must be used. Liquid cooled systems have the advantage over air cooled systems of a much higher heat transfer rate and the fact that the heat can be transported a significant distance from the source. Liquid cooled avionics have their own challenges as well. The architecture of the components (cold plates, etc) used for extracting the heat from the electronics component must be optimized to perform consistently and reliably while maintaining the smallest footprint possible in the already crowded instrument panel.
2017-09-19
Technical Paper
2017-01-2019
Rakshath G Poojary, Mohammed Ali Jouhar, Abubakar K
Human Powered Helicopter which uses man power to operate. The main aim of this paper is to design commercially available vehicle for an Adventure Sporting under 5-6 lakh Indian Rupees. This structural design is extremely lightweight and strong. The product is designed in such a way that it can be easily assembled and dismantled for transportability and storage. We developed an aero-structural optimization scheme for rotor design, including an aerodynamic model with included ground effect prediction, finite-element analysis and integrated composite failure analysis, and a detailed weight estimation scheme. This was solely build on computer CAD models. This design includes the use of gear box to increase the output. The Aerodynamic analysis was done using CFD and BET (blade element theory-Bhramwell) in MATLAB.
2017-09-19
Technical Paper
2017-01-2024
Natasha L. Schatzman, Narayanan Komerath, Ethan A. Romander
The crossing event of the blades of a coaxial counter-rotating rotor is a potential source of noise and severe blade loads. Blade crossings occur several times each rotor revolution. Most of the radial variation in the flow field can be efficiently captured by stacking the results of a 2-D analysis using two airfoils approaching each other at the appropriate relative Mach number and separation distance. Previously, this phenomenon was analyzed by simulating two airfoils passing each other at specified speeds and vertical separation distances, using the compressible Navier-Stokes solver OVERFLOW. The simulations explored thickness, circulation, and compressible effects. Results revealed the complex nature of the aerodynamic and fluid dynamic impulses generated by blade-blade interactions, with implications for aeroelastic loads and aeroacoustic sources.
2017-09-19
Technical Paper
2017-01-2030
Benjamin Cheong, Patrick Wheeler, Pericle Zanchetta, Michael Galea
In effort to reduce environmental impact of the aerospace industry, More Electric Aircraft (MEA) concepts with electrical systems for fuel pumping, wing ice protection, environmental control systems and aircraft actuation are becoming more and more widely researched. The replacement of hydraulic actuators by motor drives for flight control surfaces is particularly attractive for maintainability, reduction in operating costs and to eliminate the hydraulic fluid. High power density of aerospace motor drives is a key factor in the successful realization of these concepts. An integrated system design approach offer optimization opportunities for further improvements in power density however the challenge lies in its multi-disciplinary modelling and the handling of numerous optimization variables or constraints that are discrete and non-linear in nature. A 4-level modelling paradigm has been proposed by multiple authors to represent a motor drive.
2017-09-19
Technical Paper
2017-01-2034
Bailey Hall, Benjamin Palmer, Tyler Milburn, Luis Herrera, Bang Tsao, Joseph Weimer
Future aircrafts will demand a significant amount of flight critical electrical power to drive the primary flight control surfaces. These electrical architectures will need to meet the load requirements and provide power to the flight critical buses at all times. For this to happen, a fast, resilient, and autonomous control scheme is needed. In this presentation, formal methods and linear temporal logic are used to develop a contactor control scheme to meet the given specifications of an electrical power system. The resulting control strategy is able to manage multiple contactors during different types of generator failures, while ensuring that flight critical buses maintain power. To verify the feasibility of the proposed control scheme, a real-time simulation platform is developed. Capability to test the control strategy, along with any future versions, was implemented with a microprocessor and analog/digital I/O’s (Hardware in the Loop).
2017-09-19
Technical Paper
2017-01-2110
Ashutosh Kumar Jha, Prakash Choudhary
The complexity of software development is increasing unprecedentedly with every next generation of aircraft systems. This requires to adopt new techniques of software design and verification that could optimize the time and cost of software development. At the same time these techniques need to ensure high quality of software design and safety compliance to regulatory guidelines like DO-178C[1] and its supplements DO-330[2] and DO-331[3]. To arrive at new technologies one has to evaluate the alternate methods available for software design by developing models, integration of models, auto-code generation, auto test generation and also the performance parameters like time, effort, reuse and presentability needs to be evaluated. We have made an attempt to present summary of alternate design concept study, and edge of MBD over other design techniques.
2017-09-19
Technical Paper
2017-01-2135
Alex Thirkell, Rui Chen, Ian Harrington
Electrification of aircraft is on track to be a future key design principal due to the increasing pressure on the aviation industry to significantly reduce harmful emissions by 2050 and the increased use of electrical equipment. This has led to an increased focus on the research and development of alternative power sources for aircraft, including fuel cells. These alternative power sources could either be used to provide propulsive power or as an Auxiliary Power Unit (APU). Previous studies have considered isolated design cases where a fuel cell system was tailored for their specific application. To accommodate for the large variation between aircraft, this study covers the design of an empirical model, which will be used to size a fuel cell system for any given aircraft based on basic design parameters. The model was constructed utilising aircraft categorisation, fuel cell sizing and balance of plant sub-models.
2017-09-19
Technical Paper
2017-01-2039
Michael Sielemann, Changsoo Lee, Victor-Marie LeBrun, Chiwoo Ahn, Arnaud Colleoni, Dongkyu Lee, JeongSeok Lee, Anh Nguyen, Katrin Proelss, Hyon Min Yoon
Thermal management on aircraft has been an important discipline for several decades. However, with the recent generations of high performance aircraft, thermal management has evolved more and more into a critical performance and capability constraint on the whole aircraft level. Fuel continues to be the most important heat sink on high performance aircraft, and consequently the requirements on thermal models of fuel systems are expanding. As the scope of modeling and simulation is widened in general, it is not meaningful to introduce a new isolated modeling and simulation capability. Instead, thermal models must be derived from existing model assets, and eventually enable integration across several physical domains. This paper describes such an integrated approach based on the Modelica Fuel System Library and the 3DExperience Platform.
2017-09-19
Technical Paper
2017-01-2109
Kiran Thupakula
Airport environment consists of several object movements both in air and on ground. In air objects include aircrafts, UAVs and birds etc. On ground objects include aircrafts, airport structures, ground vehicles and ground personnel etc. Detecting, classifying, identifying and tracking these objects are necessary for avoiding collisions in all environmental situations. Multiple sensors need to be employed for capturing the object shape and position from multiple directions. Data from these sensors are combined and processed for object identification. In current scenario, there is no comprehensive traffic monitoring system that uses multisensor data for monitoring in all the airport areas. In this paper, for explanation purpose, a hypothetical airport traffic monitoring system [1] is presumed that uses multiple sensors for avoiding collisions.
2017-09-19
Technical Paper
2017-01-2155
Michal Salacinski, Piotr Broda, Piotr Samoraj
Polish Armed Forces are currently operating hundred helicopters belonging to Mi family. Metal fuselage is usually resistant to the battle and the human factor. Unfortunately, metal rotor blades of Mi helicopters are sensitive to operating conditions. Single blade is made from monolithic aluminum spar and mutually separated trailing sections, which are bonded to the spar. The sections are constructed of metal sandwich panels. During aggressive military operating conditions blades sections are often damaged by debonding from the spar, fatigue cracks of section skin, dents and perforations as well as erosion. The manufacturer assumed that structurally damaged sections should be exchanged. Provided repair technologies are applied only to cosmetic damages. Unfortunately, there is a limit to number repairs which prevents replacement of two neighboring sections due to the high temperature of curing cycle during the section replacement.
2017-09-19
Technical Paper
2017-01-2159
Federico Cappuzzo, Olivier Broca, Jeremy Leboi
To answer the ever-increasing complexity of aircraft, it becomes of foremost importance to better and earlier assess the interactions among their systems and sub-systems. The study presents the Virtual Integrated Aircraft (VIA) methodology, which allows achieving the integration of aircraft systems with virtual means, complementing and preceding physical integration, which is usually completed at the end of the validation and integration phase. LMS Imagine.Lab platform provides the means for applying this methodology. A simulation architecture, integrating models from different platforms, is built and simulations are run on High Performance Computers (HPC) to cover multiple scenarios and therefore validate the selected architecture and pre-design in the early system development phases. Equipment, systems and subsystems are essential for the performance, safety, reliability and comfort.
2017-09-04
Technical Paper
2017-24-0095
Zbynek Syrovatka, Michal Takats, Jiri Vavra
Abstract An ongoing research and development activities on the scavenged pre-chamber ignition system for an automotive natural gas fueled engine is presented in this paper. The experimental works have been performed in engine laboratory at steady state conditions on a gas engine with 102 mm bore and 120 mm stroke, converted to a single cylinder engine. The in-house designed scavenged pre-chamber is equipped with a spark plug, fuel supply and a miniature pressure sensor for detailed combustion diagnostics. The engine was operated at constant speed, fully open throttle valve and four different fueling modes with or without spark discharge. A partly motored mode allowed direct evaluation of the pre-chamber heat release. The experimental data acquired in this research served as a validation data for the numerical simulations. The performed tests of prototypes and calculations have recently been expanded to include 3-D flow calculations in the Ansys Fluent software.
2017-09-04
Technical Paper
2017-24-0133
Jelica Pavlovic, Alessandro Tansini, Georgios Fontaras, Biagio Ciuffo, Marcos Garcia Otura, Germana Trentadue, Ricardo Suarez Bertoa, Federico Millo
Plug-in Hybrid Electric Vehicles (PHEVs) are one of the main options for reducing vehicle CO2 emissions and helping vehicle manufacturers (OEMs) to meet the CO2 targets imposed by different Governments from all around the world. In Europe OEMs have introduced a significant number of PHEV models to meet their CO2 target of 95 g/km for passenger cars set for 2021. Fuel consumption and CO2 emissions from PHEVs, however, strongly depend on the way they are used and on the frequency with which their battery is charged by the user. Studies have indeed revealed that in real life, with poor charging behavior from users, PHEV fuel consumption is equivalent to that of conventional vehicles, and in some cases higher, due to the increased mass and the need to keep the battery at a certain charging level.
Viewing 1 to 30 of 19927