Browse Topic: Energy conservation
ABSTRACT Although bio-inspired legged robots have advantageous mobility, they can be very inefficient. Their intrinsic walking mobility is sometimes outweighed by the inefficiency of their drive-train. Some of these inefficiencies are due to collision losses, but they are also due to suboptimal powering schemes. This paper addresses the powering schemes and seeks to clearly delineate an optimal solution to powering the walking motion of a two-legged or biped walker. We examine a simplified model of locomotion called the “rocket car” to extract the meaningful parameters that affect time and energy cost. Using Pontryagin’s Maximum Principle, we dissect the cost function, the state equation, co-state equation, and control input constraints to describe the optimal control. The result of the paper shows a “bang-off” control, and we describe the “coasting line” between these extremes. It is not possible to find a complete closed-form solution for the problem, and numerical methods, such as
ABSTRACT Connected and automated vehicles (CAVs) leverage onboard sensing and external connectivity using Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I) and Vehicle-to-Everything (V2X) technologies to "know" the upcoming operating environment with some degree of certainty, significantly narrowing prior information gaps. These technologies have been traditionally developed and used for driver assistance and safety but are now being used to operate the vehicle more efficiently [1–5]. The eco-driving algorithm, which leverages the data available through these streams, performs two key functions: (1) acceleration smoothing and (2) eco-approach and departure (Eco-AND) at signalized intersections. The algorithm uses information from neighboring vehicles and signalized intersections to calculate an energy-efficient speed trajectory. This paper presents the development of an Android-based driver advisory application that leverages cellular Internet connectivity and Traffic
ABSTRACT This paper will discuss via case study both military and civilian hybrid vehicle development focusing on the processes required from the selection of the hybrid propulsion system architecture, component down-selection using advanced modeling and simulation tools, body/chassis development and integration, design verification testing using an advanced dynamometer test facility, and final full vehicle validation on the test track. The paper will incorporate results from the FED (Fuel Efficiency Demonstrator) program where AVL is responsible in collaboration with World Technical Services Inc., for delivering a fully developed hybrid propulsion system integrated into the demonstrator vehicle
ABSTRACT The demand for electrical power in ground combat vehicles has been consistently increasing over the years. In the years to come, abundant onboard electrical power, along with a modernized power system to manage and distribute it, will enable leap ahead capabilities for the warfighter. A carefully architected electrical power system will also help to improve fuel efficiency while reducing maintenance and logistics burden
ABSTRACT The US Army is seeking improvements in the fuel efficiency of their military vehicles.. They have initiated a number of R&D projects aimed at advancing the state-of-the-art of powertrain efficiency including demonstration in a laboratory environment. This effort will set a benchmark for the vehicle integrators, allowing them to improve future vehicle offerings. The SAIC, AVL, Badenoch, QinetiQ and Ker-Train Research team offered powertrain solutions from 7 Tons to 40 Tons that achieved the goal of 44% thermal efficiency and the stringent flexible fuel and emissions requirements. In each of these offerings the team was able to identify modifications to existing engines that allowed dramatic improvements in the thermal efficiency. These efficiency improvements were achieved through a combination of techniques, combustion cycle adjustments using in-cylinder pressure monitoring and precise control of fuel injector timing, and turbo-compounding. For the R&D project, the fuel
ABSTRACT General Dynamics Land Systems has developed an Auxiliary Power Unit (APU) that provides 508A at 28VDC, for 14.2 KW. It is a stand-alone system, independent of the vehicle systems, except for utilizing vehicle fuel and vehicle batteries. Power is generated by a 570 amp alternator that is belt-driven by a diesel engine. It is load following which improves fuel efficiency and eliminates the probability of “wet stacking.” All the major components are commercially available and the APU is ready for production
ABSTRACT One of the main thrusts in current Army Science & Technology (S&T) activities is the development of occupant-centric vehicle structures that make the operation of the vehicle both comfortable and safe for the soldiers. Furthermore, a lighter weight vehicle structure is an enabling factor for faster transport, higher mobility, greater fuel conservation, higher payload, and a reduced ground footprint of supporting forces. Therefore, a key design challenge is to develop lightweight occupant-centric vehicle structures that can provide high levels of protection against explosive threats. In this paper, concepts for using materials, damping and other mechanisms to design structures with unique dynamic characteristics for mitigating blast loads are investigated. The Dynamic Response Index (DRI) metric [1] is employed as an occupant injury measure for determining the effectiveness of the each blast mitigation configuration that is considered. A model of the TARDEC Generic V-Hull
ABSTRACT New generations of ground vehicles are required to perform tasks with an increased level of autonomy. Autonomous navigation and Artificial Intelligence on the edge are growing fields that require more sensors and more computational power to perform these missions. Furthermore, new sensors in the market produce better quality data at higher rates while new processors can increase substantially the computational power. Therefore, near-future ground vehicles will be equipped with large number of sensors that will produce data at rates that has not been seen before, while at the same time, data processing power will be significantly increased. This new scenario of advanced ground vehicles applications and increase in data amount and processing power, has brought new challenges with it: low determinism, excessive power needs, data losses and large response latency. In this article, a novel approach to on-board artificial intelligence (AI) is presented that is based on state-of-the
ABSTRACT The U.S. Department of Defense faces growing fuel demand, resulting in increasing costs and compromised operational capability. In response to this issue, the Fuel Efficient Ground Vehicle Demonstrator (FED) program was initiated in order to demonstrate a tactical vehicle with significantly greater fuel efficiency than a Humvee while maintaining capability. This article provides an overview of a systems engineering methodology for maximizing fuel efficiency and its application in concept development for the FED program. Engineering tools and methods used include tradespace definition, provisional baseline product models, decomposition of energy expenditure over the product usage cycle, structured technology market surveys, complex systems modeling & simulation tools, and design space exploration / Pareto optimization. The methodology explores the impact of technology on fuel efficiency along with other aspects of vehicle development including drive cycle definition
ABSTRACT A distinctive feature of unmanned and conventional terrain vehicles with four or more driving wheels consists of the fact that energy/fuel efficiency and mobility depend markedly not only on the total power applied to all the driving wheels, but also on the distribution of the total power among the wheels. As shown, under given terrain conditions, the same vehicle with a constant total power at all the driving wheels, but with different power distributions among the driving wheels, will demonstrate different fuel consumption, mobility and traction; the vehicle will accelerate differently and turn at different turn radii. This paper explains the nature of mechanical wheel power losses which depend on the power distribution among all the driving wheels and provides mathematical models for evaluating vehicle fuel economy and mobility. The paper also describes in detail analytical technology and computational results of the optimization of wheel power distributions among the
ABSTRACT PEO CS&CSS and CCDC GVSC, in partnership with Industry partners, are working to ensure the next generation of power generation sets and tactical wheeled vehicle systems maximize the usage of COTS, are compatible with Industry Standards, are supportable, and have growth potential to meet the needs of our Soldiers. Increasing regulations on emissions worldwide will impact commercial availability of high sulfur fuel / Jet Propulsion (JP)-8 compatible engines. It is recommended that the Army relook its regulation for JP-8 as the single fuel on the battlefield, in comparison to the potential cost of modifying COTS powertrains or procuring military unique engines in the next generation of tactical wheeled vehicles and power generation sets. The Army will realize additional performance with the ability to procure modern commercial powertrain technology, including potential improvements in power density and fuel efficiency. The Army should also consider operational requirements that
ABSTRACT A retrofittable intelligent vehicle performance and fuel economy maximization system would have widespread application to military tactical and non-tactical ground vehicles as well as commercial vehicles. Barron Associates, Inc. and Southwest Research Institute (SwRI) recently conducted a research effort in collaboration with the U.S. Army RDECOM to demonstrate the feasibility of a Fuel Usage Monitor and Economizer (FUME) – an open architecture vehicle monitoring and fuel efficiency optimization system. FUME features two primary components: (1) vehicle and engine health monitoring and (2) real-time operational guidance to maximize fuel efficiency and extend equipment life given the current operating conditions. Key underlying FUME technologies include mathematical modeling of dynamic systems, real-time adaptive parameter estimation, model-based diagnostics, and intelligent usage monitoring. The research included demonstration of the underlying FUME technologies applied to a
With increasing emphasis on sustainable mobility and efficient energy use, advanced driver assistance systems (ADAS) may potentially be utilized to improve vehicles’ energy efficiency by influencing driver behavior. Despite the growing adoption of such systems in passenger vehicles for active safety and driver comfort, systematic studies examining the effects of ADAS on human driving, in the context of vehicle energy use, remain scarce. This study investigates the impacts of a driver speed advisory system on energy use in a plug-in hybrid electric vehicle (PHEV) through a controlled experiment using a driving simulator. A mixed urban highway driving environment was reconstructed from digitalizing a real-world route to observe the human driver’s behavior with and without driving assistance. The advisory system provided drivers with an optimized speed profile, pre-calculated for the simulated route to achieve maximum energy efficiency. Participants were instructed to navigate the
Hydrogen is considered one of the most promising clean energy sources. Hydrogen fuel cells offer high energy conversion efficiency and zero emissions. But the development of hydrogen fuel cells faces many challenges, including the issue of carbon-monoxide (CO) poisoning of the fuel cell electrodes
Over the past twenty years, the automotive sector has increasingly prioritized lightweight and eco-friendly products. Specifically, in the realm of tyres, achieving reduced weight and lower rolling resistance is crucial for improving fuel efficiency. However, these goals introduce significant challenges in managing Noise, Vibration, and Harshness (NVH), particularly regarding mid-frequency noise inside the vehicle. This study focuses on analyzing the interior noise of a passenger car within the 250 to 500 Hz frequency range. It examines how tyre tread stiffness and carcass stiffness affect this noise through structural borne noise test on a rough road drum and modal analysis, employing both experimental and computational approaches. Findings reveal that mid-frequency interior noise is significantly affected by factors such as the tension in the cap ply, the stiffness of the belt, and the properties of the tyre sidewall
Safe and efficient energy storage is important for American prosperity and security. With the adoption of both renewable energy sources and electric vehicles on the rise around the world, it is no surprise that research into a new generation of batteries is a major focus. Researchers have been developing batteries with higher energy storage density, and thus, longer driving range. Other goals include shorter charging times, greater tolerance to low temperatures, and safer operation
The next-gen 15-liter diesel engine meets all 2027 EPA emissions regulations while boosting fuel efficiency. Cummins provided extensive details of the design and engineering efforts involved in developing the new HELM version of its X15 diesel engine. The company says its new engine will offer up to a 7% improvement in fuel economy compared to the current EPA 2024-certified X15 while also meeting all 2027 emissions targets. Truck & Off-Highway Engineering was invited to tour the company's headquarters in Columbus, Indiana, where journalists were given a comprehensive update on the hardware powering the latest X15
As the demand for EVs grows, it will be necessary to innovate batteries that achieve durability, power density, safety, lower cost, increased range, and faster recharge time using a fast, cost-effective, and energy-efficient process
Energy efficiency in both internal combustion engine (ICE) and electric vehicles (EV) is a strategic advantage of automotive companies. It provides a better user experience that emanates amongst others from the reduction in operation expenses, particularly critical for fleets, and the increase in range. This is especially important in EVs where customers may experience range anxiety. The energetical impact of using the air conditioning system in vehicles is not negligible with power consumptions in the range of kilowatts, even with a stopped vehicle. This becomes particularly important in areas with high temperature and humidity levels where the usage of the air conditioning systems becomes safety factor. In such areas, drivers are effectively forced to use the air conditioning system continuously. Hence, the air conditioning system becomes an ideal choice to deploy control strategies for optimized energy usage. In this paper, we propose and implement a control strategy that allows a
Effective thermal management is crucial for vehicles, impacting both passenger comfort and safety, as well as overall energy efficiency. Electric vehicles (EVs) are particularly sensitive to thermal considerations, as customers often experience range anxiety. Improving efficiency not only benefits customers by extending vehicle range and reducing operational costs but also provides manufacturers with a competitive edge and potential revenue growth. Additionally, efficient thermal management contributes to minimizing the environmental impact of the vehicle throughout its lifespan. Digital twins have gained prominence across various industries due to their ability to accelerate development while minimizing testing costs. Some applications have transitioned to comprehensive three-dimensional models, while others employ model reduction techniques or hybrid approaches that combine different modeling methods. The discovery of unknown working mechanisms, more efficient and effective control
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