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Viewing 1 to 30 of 12592
Technical Paper
2014-10-13
Chunshan Li, Guoying Chen, Changfu Zong
This paper presents a fault-tolerant control (FTC) approach for four-wheel independently driven and steered (4WID/4WIS) electric vehicles. An adaptive control-based passive fault-tolerant controller is designed to improve vehicle safety, performance and maneuverability when an actuator fault happens. The proposed fault tolerant control method consists of the following three parts: 1) a fault detection and diagnosis (FDD) module that monitors vehicle driving condition, detects and diagnoses actuator failures with the inequality constraints ; 2) a motion controller that computes the generalized forces/moments to track the desired vehicle motion using Model Predictive Control (MPC); 3) a reconfigurable control allocator that redistributes the generalized forces/moments to four wheels with equality constrained optimization. The FTC approach is based on the reconfigurable control allocation which reallocates the generalized forces/moments among healthy actuators once the actuator failures is detected.
Technical Paper
2014-10-13
Nicolas Arnault, Guy Monsallier
Cold weather is a challenge for compression ignition engines. As Diesel fuel creates wax crystals and gel when temperature goes down enough (sometimes just below 0°C), it comes to plug the fuel filter and the fuel injection system, leading to undesirable effects like loss of power, engine stall after start or even engine not starting at all. Side effects like fuel feeding pump durability can also be linked to it. Moreover, it has been shown that BioDiesel, and especially FAME coming from Palm, Tallow or Used Kitchen Oil has negative impacts on vehicle cold flow operability. Literature has even identified the key fuel components which impact the cold flow properties. Fuel cold flow properties can be improved through additives, which can be already included in the fuel at the pump, or manually added by the driver. But, obviously this cannot be easily controlled on the field and car manufacturers cannot handle in advanced where the fuel fill-up will be done, nor the quality of the fuel fed in the vehicle tank.
Technical Paper
2014-10-13
Dai Liu, Hongming Xu, Ramadhas Arumugam Sakunthalai, Jianyi Tian
Cold start is a critical operating condition for diesel engines because of the resultant pollutant emissions produced by the unstable combustion at lower temperatures. In this research work, a light-duty, turbocharged diesel engine equipped with a common rail injection system was tested on a transient engine testing bed for an investigation of the starting process in terms of engine performance and emissions. The engine (including engine coolant, engine oil and fuel) was soaked in a cold cell at -7°C for at least 8 hours before starting of the test. The engine operating parameters such as engine speed, air/fuel ratio and EGR rate were recorded during the tests. Pollutant emissions (HC, NOx and particles both in mode of nucleation and accumulation) were measured before and after DOC. The results showed that conversion efficiency of NOx was higher during acceleration period at -7°C start than the case at 20°C start. The reduction of NOx and THC by DOC was less during idle period at -7°C cold start.
Technical Paper
2014-10-13
Antonino La Rocca, David MacMillan, Paul Shayler, Michael Murphy, Ian Pegg
Cold idle operation of a modern design light duty diesel engine and the effect of multiple pilot injections on stability were investigated. Magnitude and cycle-to-cycle variation of indicated parameter have been used as key indicators of cold idle performance. The utility of different injection strategies, up to three pilot injections before a main, is investigated. The investigation was initially carried out experimentally at 1000rpm, a speed representative of idle conditions, and at -20ºC. Benefits of mixture preparation were initially explored by a heat release analysis performed for each case. A CFD investigation was then used to visualise the effect of multiple pilots on in-cylinder mixture distribution, with particular emphasis on how the injection patterns affect the mixture distribution in the proximity of the glow plug. Kiva 3v was used to model the combustion system and fuel injections. A 60º mesh was used taking advantage of rotational symmetry. Combustion system and injector arrangements mimic the HPCR diesel engine used in the experimental investigation.
Technical Paper
2014-10-13
Xianjing Li, Liguang Li
Gasoline Direct Injection (GDI) engines have attracted interest as automotive powerplants because of their potential advantages in down-sizing, fuel efficiency and in emissions reduction. In modern gasoline combustion concepts the application of direct injection combined with stratification is one of the most promising strategies. However, GDI engines suffer from elevated unburned hydrocarbon (HC) emissions at the start up process, which are sometimes worsened by misfires and partial burns. Moreover, as the engine is cranked to idle speed quickly in HEV mode, the transients are more dramatically than that in traditional vehicle, which are harmful to combustion and emission performance. This paper concerned about the GDI engine performances for ISG HEVs during the start-up process. A servo motor was connected directly to the engine output shaft to simulate the ISG. Based on the test system, cycle-controlled of the fuel injection mass, fuel injection timing, ignition timing and so on, can be obtained, as well as the cycle-resolved measurement of the HC concentrations and NO emissions.
Technical Paper
2014-10-13
Krzysztof Jan Siczek
Nowadays microbes like bacteria are used to wring out electrical energy trapped in wastewater. Such bacterial batteries use oxygen at the cathode to soak up the harvested electrons. Oxygen is used because of its efficiency during collecting electrons. Unfortunately such mini power plants can be treacherous and sensitive to leak of oxygen and microbes. The oxygen can bubble over to the anode and the bacteria can migrate closer to the cathode to swipe the gas for their own energy production. They can also case risks a short circuit. In the case of such battery it is a real problem the control of gas flow and behaviour. To prevent spillover between electrodes in such batteries, engineers use the complex membrane barriers should be used. Replacing of bubbling oxygen with solid silver oxide that gobbles up electrons allows creating rechargeable bacterial battery. For both fuel cell and microbe-based battery it is needed a place to send electrons, but putting oxygen in there is a real problem.
Technical Paper
2014-10-13
Cheng Tan, Hongming Xu, He Ma, Jianyi Tian, Akbar Ghafourian
Automotive engines especially turbocharged diesel engines produce higher level of emissions during transient operation than in steady state. Therefore, the study of engine transients has received increasing attention for meeting the new emission legislations. In order to improve understanding of the engine transients and develop advanced technologies to reduce the transient emissions, the engine researchers require accurate data acquisition and appropriate post-processing techniques which are capable of dealing with noise and synchronization issues. The objective of this study is to develop a methodology for the measurement and processing of data during transient engine tests concerning the noise in time-resolved data during the transient which requires proper filtering. A common practice in engine tests is ensemble averaging the data of a number of cycles for the steady state experiments but this method is not suitable for the transient cases. In this study, four alternative automated methods were implemented on in-cylinder pressure data of each individual cycle to compare and analyze the suitability of combustion diagnostic.
Technical Paper
2014-10-13
Ramadhas Arumugam Sakunthalai, Hongming Xu, Dai Liu, Jianyi Tian, Miroslaw Wyszynski, Jakub Piaszyk
The cold start performance of diesel engines has been receiving more attention when the European Commission emission regulations directed to include the cold start emissions in the legislative emission driving cycles. The cold start performance of diesel engines is influenced by the ambient conditions, engine design, fuel, lubricant and engine operating conditions. The present research work investigates the effect of the cold ambient conditions on the engine idle speed stability and the exhaust emissions (gaseous and particle emissions) from the diesel engine during the cold start and followed by idle conditions. The engine startability and idling tests were carried out on the diesel engine in the cold cell at the different ambient temperatures ranges between +20 ºC and -20 ºC. The higher fuel consumption and peak speed observed at very cold ambient temperatures have been compared to those at ambient conditions. The exhaust emissions of the engine were higher at cold start and then it started decreasing during idle.
Technical Paper
2014-09-30
Antoine Delorme, Jason L. Robert, William Eli Hollowell, Andre M. Strobel, Jason T. Krajewski
Abstract In the recent years, Automated Manual Transmissions have become more popular for class 8 heavy trucks. Besides the benefits of smoother gear changes and reduced driver fatigue, AMTs can also greatly reduce fuel consumption by using optimized shifting strategies and advanced controls. The Detroit DT12 AMT demonstrated its ability to save fuel over a standard AMT, due in part to its eCoast feature. eCoast relies on intelligent and advanced electronic controls to safely allow the vehicle to coast on downgrades. While the engine is idling, the drag parasitic energy losses are decreased and the vehicle can fully use its momentum to travel further up and down hill. As one could expect, the type of route profile can greatly affect the fuel savings due to eCoast, since more hilly terrains might offer more opportunities to activate eCoast than flatter roads. In addition, when combined with different vehicle and driving parameters such as vehicle weight and driver desired cruise set speed, the fuel consumption reduction of eCoast is always there, but becomes a more complicated function.
Technical Paper
2014-09-30
Daofei Li, Lei Wang, Huanxiang Xu, Zhipeng Fan, Xiaoli Yu
Abstract Braking energy recovery can significantly contribute to fuel economy and emission reduction, particularly for commercial vehicles driving in urban environment. By using the compressed air storage, rather than expensive and vulnerable batteries, this paper proposes a pneumatic hybrid system with an integrated compressor/expander unit (CEU) for commercial vehicles, in order to achieve stop/start function and braking energy recovery. During braking, the compressed air is recovered by CEU working in compressor mode and is charged to the air tanks. When the vehicle starts from stop, the CEU works as an expander to crank the engine with compressed air. The compressed air can also be used to supply the air tank of brake boost system, thus reducing its energy consumption. The mathematical models of energy conversion units, including the two modes of CEU and the air brake system, are established and analyzed. A preliminary case study of an urban bus application shows that, in an urban driving cycle, the compressed air recovered from braking is sufficient both for engine cranking and air brake system.
Technical Paper
2014-09-30
Hiroyuki Ishizaka, Kazuo Tanaka, Motoyasu Tanaka, Yusuke Tanaka
Abstract For the purpose of reducing fuel consumption, a hybrid heavy duty truck was considered. Generally, HV (Hybrid Vehicle)'s energy is regenerated from deceleration energy in urban area. Hybrid heavy duty truck's energy is regenerated from potential energy on highway. Under this circumstance, some portion of energy may not be accumulated, because capacity of HV battery is limited. In order to maximize accumulating energy in the next descent, HV battery's energy shall be adequately reduced beforehand. This can be achieved by optimizing motor assist torque considering road's altitude and gradient. In this paper, performance of the algorithm is discussed.
Technical Paper
2014-09-30
Demetrio Cortese
Abstract Using a Model-based approach to the embedded software development process contributed significantly in reducing the development time while also supporting a high quality level of the software code implementation. However, based on our experience with CNH Industrial application scenarios, involving multiple suppliers from vehicle ECU to the engine ECU, it only addressed the need of the implementation phase without any consistent influence in other software development life-cycle phases such as requirements and specification. Mandatory functional safety requirements, new complex functionalities, and reducing time to delivery while maintaining high quality level of software are driving factors in our new software development projects. Ideally the adoption of international standards, as for example the ISO 12007, and the safety standards, as the ISO 26262, ISO 25119 and ISO 13849, should represent a consistent guide to develop software. In this approach, the adoption of them should satisfy both the development guidelines and recommendations while at the same time to meeting application scenario requirements.
Technical Paper
2014-09-30
Jeffrey K. Ball, Mark Kittel, Trevor Buss, Greg Weiss
Abstract Trucking fleets are increasingly installing video event recorders in their vehicles. The video event recorder system is usually mounted near the vehicle's rear view mirror, and consists of two cameras: one looking forward and one looking towards the driver. The system also contains accelerometers that record lateral and longitudinal g-loading, and some may record vehicle speed (in mph) based on GPS positions. The unit constantly monitors vehicle acceleration and speed, and also records video. However, the recorded data is only stored when a preset acceleration threshold is met. The primary use of the system is to assist fleets with driver training and education, but the recorded data is also being used as a tool to reconstruct accidents. By integrating the accelerometer data, the vehicle speed and distance traveled during the event can be calculated. However, the calculated speeds and distances from video event recorder data may differ from reconstructions based on data taken from engine control modules (ECM's) or classic reconstruction techniques.
Technical Paper
2014-09-30
Michael Sprengel, Monika Ivantysynova
Abstract A novel Blended Hydraulic Hybrid transmission architecture is presented in this paper with benefits over conventional designs. This novel configuration combines elements of a hydrostatic transmission, a parallel hybrid, and a selectively connectable high pressure accumulator using passive and actively controlled logic elements. Losses are reduced compared to existing series hybrid transmissions by enabling the units to operate efficiently at pressures below the current high pressure accumulator's pressure. A selective connection to the high pressure accumulator also allows for higher system precharge which increases regenerative braking torque and energy capture with little determent to system efficiency. Finally operating as a hydrostatic transmission increases transmission stiffness (i.e. driver response) and may improve driver feel in certain situations when compared to a conventional series hybrid transmission. To explore the novel blended hybrid architecture six transmissions were modeled and simulated.
Technical Paper
2014-09-30
Massimiliano Ruggeri, Pietro Marani
Abstract The new X-by-Wire systems under study for commercial and heavy-duty vehicles, as well as for Agricultural Tractors, are increasingly real autonomous systems, capable to autonomously control a vehicle functionality, actuating the operator's commands, or managing in a complete autonomy a machine function. These application need an higher Performance Level from the functional safety point of view, due to the risk of a malfunction consequence. The paper deals with a new concept hydraulic spool valve that allow the design of new safer and more compacted hydraulic circuit architectures, ensuring higher safety performance levels. The architecture presents advantages both from performance (precision, fastness), both from operational point of view. The paper will focus in particular on safety and control topics. The new patented valve presents a secondary rotary type actuator connected to a sleeve interposed between the spool and the valve body, thus composing a roto-translating valve.
Technical Paper
2014-09-30
Alexander Sappok, Leslie Bromberg
Abstract Diesel Particulate Filters (DPF) are a key component in many on- and off-road aftertreatment systems to meet increasingly stringent particle emissions limits. Efficient thermal management and regeneration control is critical for reliable and cost-effective operation of the combined engine and aftertreatment system. Conventional DPF control systems predominantly rely on a combination of filter pressure drop measurements and predictive models to indirectly estimate the soot loading state of the filter. Over time, the build-up of incombustible ash, primarily derived from metal-containing lubricant additives, accumulates in the filter to levels far exceeding the DPF's soot storage limit. The combined effects of soot and ash build-up dynamically impact the filter's pressure drop response, service life, and fuel consumption, and must be accurately accounted for in order to optimize engine and aftertreatment system performance. This work applied a radio frequency (RF) sensor to directly monitor diesel particulate filter soot and ash levels, thereby enabling direct feedback control of the filter based on its actual loading state.
Technical Paper
2014-09-30
Tyson McWha
Abstract Transport Canada, through its ecoTECHNOLOGY for Vehicles program, retained the services of the National Research Council Canada to undertake a test program to examine the operational and human factors considerations concerning the removal of the side mirrors on a Class 8 tractor equipped with a 53 foot dry van semi-trailer. Full scale aerodynamic testing was performed in a 2 m by 3 m wind tunnel on a system component basis to quantify the possible fuel savings associated with the removal of the side mirrors. The mirrors on a Volvo VN780 tractor were removed and replaced with a prototype camera-based indirect vision system consisting of four cameras mounted in the front fender location; two cameras on either side of the vehicle. Four monitors mounted in the vehicle - two mounted on the right A-pillar and two mounted on the left A-pillar - provided indirect vision information to the vehicle operator. Four commercial drivers were asked to perform a series of tests simulating typical driving scenarios on a closed course test track.
Technical Paper
2014-09-30
Quon Kwan, Leverson Boodlal
In this particular field study, the authors have demonstrated that telematics can be used to monitor and improve safe and fuel-efficient driving behavior. Telematics was used to monitor various driver performance parameters: unsafe events (sudden accelerations and hard braking expressed as Yellow and Red events, depending on severity), speeding, engine revolutions per minute (RPM), and fuel economy (miles per gallon). The drivers consisted of two groups: drivers of day cabs and drivers of sleeper cabs. The drivers of both groups were monitored during a baseline period during which no feedback, coaching, or rewards were provided. Then, the drivers of both groups were monitored during an intervention period, during which drivers were provided with feedback, coaching, and rewards. As the result of monitoring unsafe events and of driver intervention, drivers of sleeper cabs showed a 55 percent reduction from the baseline in less severe (Yellow) unsafe events and a 60 percent reduction from the baseline in more severe (Red) unsafe events.
Technical Paper
2014-09-30
Raghuram Krishnamurthy, Rani Mukherjee
Abstract Safety compliance has a new set of difficult questions to address due to the usage of COTS, OSS and externally supplied software code in automotive systems. The use of third-party software component is essential to business as it helps in reduction of cost and development cycle. However, there are many technical risks encountered when incorporating Third-Party Software (TPSW) components into safety related software. Moreover, safety systems conforming to new automotive safety standard ISO 26262 are expected to satisfy criteria for co-existence of TPSW with internal safety related software and legacy code. The purpose is to avoid a potential failure that may be triggered by TPSW which in turn may propagate to cause failure in other software partitions. There are several options available to address the above requirements. We should carefully evaluate the TPSW's functionality and pedigree and apply combination of techniques to assist in supporting the intent of ISO 26262. This paper discusses on the issues concerning insertion of third party software code (OEM supplied code, Tier 2 vendor software) into in-house developed ECU software.
Technical Paper
2014-09-30
Massimiliano Ruggeri, Carlo Ferraresi, Luca Dariz, Giorgio Malaguti
Abstract Functional safety requirements and solutions are more expensive when it comes to lower cost machines with less power but same functionalities with respect to big machines. The paper will show a real Electronic Control Unit (ECU) design of a machine controller, controlling both engine working point, transmission, and other utilities like PTO, 4WD, brakes and Differential Lock; the ECU was designed in accordance to ISO 25119 regulation, to meet AgPL = C or even D for some functionalities. The unit is a fully redundant electronic control unit with two CAN networks and some special safe state oriented mechanism, that allow the Performance Level C with less software analysis requirements compared with traditional solutions. All safety critical sensors are redounded and singularly diagnosable, all command effects are directly observable and most of commands are directly diagnosable. With a minimum extra-cost the hardware category for the most critical controls was brought to the category 4, thus theoretically allowing the Performance Level D achievement.
Technical Paper
2014-09-30
Giorgio Malaguti, Carlo Ferraresi, Luca Dariz, Massimiliano Ruggeri
Abstract Alongside with the increasing vehicle complexity, the functionalities related to the safety, diagnosis and maintainability have become critical. The operators of special machines such as agricultural, mining, construction vehicles might be overwhelmed by this increased complexity and, as a result, operations for the recovery or maintenance of their vehicles become difficult. The Augmented Reality (AR) seems to be a very promising technology both if applied to traditional smart-phones or to the upcoming glasses, that has been just presented to the market by several manufacturers. This paper reviews some use cases of applications created in Institute for Agricultural and Earthmoving Machines (IMAMOTER) of the National research Council of Italy (CNR) engineers laboratories, which propose a novel approach for assisted maintenance, recovery or training. These take advantage of the use of AR, providing an efficient method for user fast learning of simple procedures as well as a support for fault recovery and maintenance in hazardous environments or work places.
Technical Paper
2014-09-30
Jennifer Wheeler, Joshua Stein, Gary Hunter
Abstract Recent advances in natural gas (NG) recovery technologies and availability have sparked a renewed interest in using NG as a fuel for commercial vehicles. NG can potentially provide both reduced operating cost and reductions in CO2 emissions. Commercial NG vehicles, depending on application and region, have different performance and fuel consumption targets and are subject to various emissions regulations. Therefore, different applications may require different combustion strategies to achieve specific targets and regulations. This paper summarizes an evaluation of combustion strategies and parameters available to meet these requirements while using NG in a spark ignited engine. A single-cylinder research engine using a modified diesel cylinder head was employed for this study. Both stoichiometric combustion with cooled exhaust gas recirculation (EGR) and lean-burn were evaluated. Testing quantified the effects of dilution (EGR or excess air), swirl ratio, and compression ratio on the operating limits, engine-out emissions, and fuel efficiency at operating conditions typical for heavy-duty vehicle applications.
Technical Paper
2014-09-28
Chendi Sun, Xiaofei Pei
Abstract This paper presents how hardware-in-the-loop (HIL) simulations have been used for testing during the development of ABS (Anti-lock Braking System). The Labcar system of ETAS is a popular tool for HIL tests. The vehicle model which is built in Matlab/Simulink is downloaded to run in RTPC (Real-time PC). The Labcar software, Integration Platform (IP), can configure boards which is a link between the model and ABS ECU. In this paper, a classical logic threshold control algorithm is adopted in ABS ECU. Through Labcar Experiment Environment (EE) various parameters can be monitored and modified conveniently. The HIL test of ABS ECU is implemented on high or low - adhesion road respectively. The results show that, although response lag exists in the hydraulic braking system, the curves of velocity and pressure in wheel cylinders can be close to those on real road with proper adjustment of control parameters. So HIL simulations are invaluable, when considering the short development time required in the automotive industry.
Technical Paper
2014-09-28
Mandeep Singh Walia, Magnus Karlsson, Lars Hakansson, Gaurav Chopra
Abstract An analysis method to study the potentials of recovering the brake energy from Volvo articulated haulers has been developed. The study has been carried out with purpose to find out how and where possible hybrid solutions can be used. The method is based on the mapping of the peak brake power, brake energy and engine energy. This method was developed using adequate signals collected on haulers at three different customer sites. A conceptual study was also carried out concerning the brake energy to understand the actual amount of brake energy that may be stored in an Energy storage system (ESS). The results indicate that the analysis method developed can map the brake energy generated and also provide an overview of the actual amount of brake energy that can be accumulated in an ESS. Hence, the method may also providing guidelines regarding the selection of an ESS for a particular work site.
Technical Paper
2014-09-28
Gunn Hwang, Axel Freiwald, Hyun-Sik Ahn
Abstract Currently major investments by Tier1 and vehicle manufacturers are made to implement and optimize safety critical automotive systems according to the ISO standard 26262 “Road vehicles functional safety”. The ISO 26262 standard describes methods to detect the safety critical faults of a system designed according to the rules of functional safety, but it does not describe how an actual implementation shall look like. Development of ISO 26262 standard compliant systems concentrates on optimizing and improving cost and performance in a competitive environment. More competitive and practical implementations use fewer additional hardware and software resources for safety control and error detection and have higher performance with less overhead. Microcontrollers already have implemented many safety related hardware functions, so called safety mechanisms to mitigate safety critical risks. Depending on how these safety mechanisms are used, functional safety compliant system can get optimized for cost and performance.
Technical Paper
2014-09-28
Liang Zhou, Chuqi Su
Abstract Recovering the braking energy and reusing it can significantly improve the fuel economy of hybrid electric vehicles (HEVs).The battery ability of recovering electricity limits the improvement of the regenerative braking performance. As one way to solve this problem, the technology of brake-by-wire can be adopted in the HEVs to use the recovery dynamically. The use of high-power electrical equipment, such as electromechanical brake (EMB), is working in the form of brake-by-wire. Due to the nature of EMB, there exists an obvious coupling relationship between the energy flow and brake force distribution. In this paper, a brake force distribution controller is proposed in HEV with EMB, which can maximize braking energy recovery, compared with the conventional distribution control without EMB. Meanwhile, an energy flow strategy working with the distribution controller is designed, which is less limited to the performance of the battery. In this strategy, the recovery transfers to the motor of EMB directly, rather than being stored statically in the battery, so it improves the efficiency of the braking energy recovery.
Technical Paper
2014-09-28
Kyung-Jung Lee, Jae-Min Kwon, Jae Seung Cheon, Hyun-Sik Ahn
Abstract This paper proposes a design approach for the network configuration of brake-by-wire (BBW) systems using the FlexRay communication protocol. Owing to the absence of mechanical or hydraulic back-ups, the BBW system needs to be highly reliable and fault-tolerant. The FlexRay network is shown to be very effective for such requirements of BBW systems by using hardware in-the-loop simulation (HILS), which allows developing and testing various algorithms and faithfully reproduces the actual system. The FlexRay protocols are designed using the FIBEX configuration tool appropriately for the control of BBW systems, and they are analyzed using the FlexRay communication monitoring tool. The results of HILS illustrate that the braking performance of a controller area network (CAN)-based network and that of a FlexRay-based network for BBW systems are very similar, however, the FlexRay-based network system is more reliable and ensures better fault diagnosis by monitoring more variables.
Technical Paper
2014-09-28
Zhizhong Wang, Liangyao Yu, Yufeng Wang, Kaihui Wu, Ning Pan, Jian Song, Liangxu Ma
Abstract The four-wheel-independent Electro-hydraulic Braking system (4WI EHB) is a wet type Brake-by-Wire system for passenger vehicle and is suitable for electric vehicle (EV) and hybrid electric vehicle (HEV) to cooperate with regenerative braking. This paper gives a review on the design concepts of the 4WI EHB from the following three aspects. 1. Hydraulic architectures. 2. Design concepts of the brake actuator. 3. Installation of the components on the vehicle. Simulations and experiments are carried out to further explore the performance of hydraulic backup and implicit hardware redundancy (IHR). A method to integrate the IHR with hydraulic backup without increasing the total amount of valves is proposed, making the IHR cost and weight competitive. By reviewing various design concepts and analyzing their advantages and drawbacks, a cost and weight competitive design concept of the 4WI EHB with good fail-safe and fault-tolerant performance is proposed.
Technical Paper
2014-09-16
Jon Zumberge, John Mersch
Cost and performance requirements are driving military and commercial systems to highly integrated, optimized systems which require more sophisticated, highly complex controls. To realize benefits and make confident decisions, the validation of both plant and control models becomes critical. To quickly develop controls for these systems, it is beneficial to develop models and determine the uncertainty of those models so as to predict performance and stability. A process of model validation for a boost circuit based on acceptance sampling is presented here. The validation process described in this paper includes the steps of defining requirements, performing a screening and exploration of the system, completing a system and parameter identification, and finally executing a validation test. To minimize the cost of experimentation and simulation, design of experiments is used extensively to limit the amount of data taken without losing information. One key contribution in this paper is the use of tolerance intervals as an estimation of model accuracy.
Technical Paper
2014-09-16
Joseph Dygert, Melissa Morris, Patrick Browning
Abstract The high demand for traditional air traffic as well as increased use of unmanned aerial systems (UAS) has resulted in researchers examining alternative technologies which would result in safer, more reliable, and better performing aircraft. Active methods of aerodynamic flow control may be the most promising approach to this problem. Research in the area of aerodynamic control is transitioning from traditional mechanical flow control devices to, among other methods, plasma actuators. Plasma actuators offer an inexpensive and energy efficient method of flow control. Dielectric Barrier Discharge (DBD), one of the most widely studied forms of plasma actuation, employs an electrohydrodynamic (EHD) device which uses dominant electric fields for actuation. Unlike traditional flow control methods, a DBD device operates without moving components or mass injection methods. Publications discussing the optimization of DBD flow control versus a single variable such as gap width, voltage, dielectric constant, etc., have been widely published, and instigated a 2003 paper published by the IEEE-DEIS-EHD Technical Committee titled “Recommended International Standard for Dimensionless Parameters Used in Electrohydrodynamics.”
Viewing 1 to 30 of 12592