Browse Topic: Stop / start technology
ABSTRACT The 2015 defense budget, announced in March, 2014 was requested to be $496 Billion, which is down from $553 Billion three years ago [1]. This means that existing equipment, which has been trained on for numerous years, and fought two major wars, will be required to last longer and be maintained at a high state of readiness for years to come. In addition to acquisition and maintenance costs, fuel that propels these vehicles continues to also be at a premium. According to Forbes magazine, the US Department of Defense is the single-largest consumer of fuel in the world [2]. With fuel costs as volatile as ever, and an aging military fleet, researchers need to bring technology to the table that extends the life cycle of our vehicles and reduces the US DoD’s dependence on fuel. Technology that addresses both life cycle cost and fuel savings of commercial vehicles has been used for almost 40 years. This technology is a game changer for specialty vehicles such as police cars
Commercial transportation is the key pillar of any growing economy. Light and Small commercial vehicles are increasing every day to cater the logistics demand, but there is always a gap between customer’s actual and desired operational efficiency. This is because of lack of organized fleet and efficient fleet operation. The major requirement of fleet owners is timely delivery, high productivity, downtime reduction, real time tracking, etc., Automakers are now providing fleet management application in modern LCV & SCV to satisfy the fleet operator requirement. However, any feature malfunction, consignment mismatch, wrong notification, missed alerts, etc., can incur huge loss to fleet operator and disrupt the entire supply chain. Hence it is very critical to extensively validate the telematics features in fleet management application. This paper explains the approach for exhaustive validation strategy of fleet management applications (B2B) from end user perspective. An effective test
Cummins announced its seventh-generation series HE250 and HE300 waste-gate turbochargers for medium displacement on- and off-highway commercial engines. The turbos are sized for 5.5- to 8-liter medium-duty diesel engines and 8- to 11-liter natural-gas engines. Cummins states that the HE250 and 300 were designed to meet the global emissions regulations from 2024 onwards including the upcoming China Stage IV FE 2024, NSVII 2026 and Euro VII 2027. Cummins claims significant improvements in performance and durability compared to the outgoing models. Both turbos reportedly offer a 6-7% gain in overall efficiency as well as enhanced low-speed performance, which translates to additional low-end torque and better compatibility with engine start/stop systems
This SAE Recommended Practice applies to motor vehicle forward illumination systems and subsystems generated by discharge sources. It provides test methods, requirements, and guidelines applicable to the special characteristics of gaseous discharge lighting devices which supplement those required for forward illumination systems using incandescent light sources. The document is applicable to both discharge forward lighting systems, subsystems and components. This document is intended to be a guide to standard practice and is subject to change to reflect additional experience and technical advances
This SAE Recommended Practice applies to motor vehicle forward illumination systems and subsystems generated by discharge sources. It provides test methods, requirements, and guidelines applicable to the special characteristics of gaseous discharge lighting devices which supplement those required for forward illumination systems using incandescent light sources. The document is applicable to both discharge forward lighting systems, subsystems and components. This document is intended to be a guide to standard practice and is subject to change to reflect additional experience and technical advances
As the electrification of automobiles continues to accelerate, the need for a safe, reliable, high-power energy-storage technology is greater than ever. Ultracapacitors already have an established place in Voltage Stabilization Systems (VSS) for internal-combustion engine (ICE) stop-start applications. By providing additional voltage support during a high-current cranking event, voltage levels are maintained to allow proper operation of accessories without interruption and enable proper operation as battery state-of-health declines
In the current situation and upcoming government regulations, hybrid vehicles are very promising in terms of meeting fuel economy and stringent requirements of emission norms. Herein, hybridization will be mostly done with gasoline and CNG vehicles. As a normal practice, engine is switched off at the signal and again restart with engine start-stop technology. So, instances of engine start/stop are increased in hybrid vehicle in comparison with standard IC engine vehicle. In order to achieve smooth engine start, engine starting torque can be optimized by adjusting engine valve timing. As Electric Cam Phaser (ECP) meets valve timing target even before first engine combustion start, this is one of the critical technologies in reducing engine starting torque and time reaching to idle speed. This engine starting strategy also gives benefits in terms of reducing engine start emissions and improving fuel economy. This paper describes selection of electric cam phaser for hybrid vehicle
As computer-aided engineering software tools advance, more simulation-based processes are utilized to reduce development time and cost. Traditionally, during the development of a new control algorithm dyno or on-road testing is necessary to validate a new function, however, physical testing is both costly and time consuming. This study introduces a co-simulation platform and discusses its use as an improved method of powertrain control logic development. The simulation platform consists of a dynamic vehicle model, virtual road network and simulated traffic objects. Engineers can utilize Matlab/Simulink along with other programs such as PTV Vissim, Tass Prescan, and AVL Cruise to create an integrated platform capable of testing and validating new control strategies. The structure and configuration of this virtual platform is explained in this paper, and an example use case is demonstrated. A driver model was developed to simulate realistic vehicle inputs. Validation of this new driver
In this work, a dynamically loaded hydrodynamic journal bearing test rig is developed and introduced. The rig is a novel design, using a hydraulic actuator with fast acting spool valves to apply load to a connecting rod. This force is transmitted through the connecting rod to the large end bearing which is mounted on a spinning shaft. The hydraulic actuator allows for fully variable control and can be used to apply either static load in compression or tension, or dynamic loading to simulate engine operation. A variable speed electric motor controls shaft speed and is synchronized to the hydraulic actuator to accurately simulate loading to represent all four engine strokes. A high precision torque meter enables direct measurements of friction torque, while shaft position is measured via a high precision encoder. Data generated on the test rig is also presented, and includes frictional torque loss, cumulative energy consumption during transient operation, and starting energy during stop
The definition of the energy management strategy for a hybrid electric vehicle is a key element to ensure maximum energy efficiency. The ability to optimally manage the on-board energy sources, i.e., fuel and electricity, greatly affects the final energy consumption of hybrid powertrains. In the case of plug-in series-hybrid architectures, such as Range-Extender Electric Vehicles (REEVs), fuel efficiency optimization alone can result in a stressful operation of the range-extender engine with an excessively high number of start/stops. Nonetheless, reducing the number of start/stops can lead to long periods in which the engine is off, resulting in the after-treatment system temperature to drop and higher emissions to be produced at the next engine start. In this work, Dynamic Programming is used to define the optimal energy management strategy for the REEV with a multi-objective cost function that takes into account not only fuel consumption, but also engine start/stops and pollutant
Diesel engine cold start is emerging as a critical topic of investigation. Of key importance is the impact the warm-up period has on particulate emissions. Presented in this work is a fundamental and comprehensive study on the impact of cold, warm, and hot start on particulate emissions over a custom quasi-steady-state drive cycle discretized by frequent engine stop/start. The experiments were conducted on a six-cylinder, turbocharged, diesel engine. Compared with cold start, the count median diameter (CMD) increased by 16% and 5% in the Aitken mode at 1500 rpm and 2000 rpm, respectively, when the engine was fully warmed up. The geometric standard deviation (GSD) decreased as the engine warmed up. Particle number (PN) concentration decreased by 50% as the engine coolant temperature reached 70°C, compared to cold start (23°C), and a strong positive linear correlation was found between the particle mass (PM) and PN emissions at all loads. This work explores the topic of engine warm-up
The three-way-catalyst (TWC) is an essential part of the exhaust aftertreatment system in spark-ignited powertrains, converting nearly all toxic emissions to harmless gasses. The TWC’s conversion efficiency is significantly temperature-dependent, and cold-starts can be the dominating source of emissions for vehicles with frequent start/stops (e.g. hybrid vehicles). In this paper we develop a thermal TWC model and calibrate it with experimental data. Due to the few number of state variables the model is well suited for fast offline simulation as well as subsequent on-line control, for instance using non-linear state-feedback or explicit MPC. Using the model could allow an on-line controller to more optimally adjust the engine ignition timing, the power in an electric catalyst pre-heater, and/or the power split ratio in a hybrid vehicle when the catalyst is not completely hot. The model uses a physics-based approach and resolves both axial and radial temperature gradients, allowing for
Idle Stop-and-go (ISG), also known as Auto Stop/Start, is a fuel saving technology common to many modern vehicles that enables the engine to shut down when the vehicle comes to a stop. Although it may help with fuel efficiency, many drivers in the North American market find the feature to be an annoyance due to hesitation in vehicle re-launch and engine shudder during stop or restart. This paper introduces the usage of traffic signal phase and timing (SPaT) information for controlling the activation of ISG with the goal of reducing driver complaints and increasing acceptance of the function. Previous studies proposed the utilization of Advanced Driver Assistance System (ADAS) to introduce adaptability in powertrain controls to traffic situation changes. For instance, when a vehicle stops and the engine shuts off, the controller monitors the movement of the preceding vehicle using ADAS sensors and restarts the engine when the front launches, prior to the driver releasing the brake pedal
Battery models are being developed as a component of the powertrain systems of hybrid electric vehicles (HEVs) to predict the state of charge (SOC) accurately. Electrically heated catalysts (EHCs) can be employed in the powertrains of HEVs to reach the catalyst light off temperature in advance. However, EHCs draw power from the battery pack and hence sufficient energy needs to be stored to power auxiliary components. In series HEVs, the engine is primarily used to charge the battery pack. Therefore, it is important to develop a control strategy that triggers engine start/stop conditions and reduces the frequency of engine operation to minimize the equivalent fuel consumption. In this study, a battery pack model was constructed in MATLAB-Simulink to investigate the SOC variation of a high-power lithium ion battery during extreme engine cold start conditions (-7°C) with/without application of an EHC. The EHC was simulated in MATLAB to determine the energy required to heat the catalyst
Modern hybrid technologies, especially mild and micro-hybrids with auto start/stop feature, demand a starter with higher power, better performance and longer life than conventional brush-type starters. In this paper, a new starter design using a brushless motor is proposed. This improves the engine crank performance during autostarts due to lower inertia, higher torque and wider power band capability of the brushless motor, especially at higher speeds. The overall integrated system includes the motor, inverter and controller all packaged in the same form factor of the original starter housing as a “drop-in replacement”. The prototype starter motor is designed to operate at 48V with a peak power of 4kW but can be designed to operate at the standard 12V. This paper will describe in detail the functionalities of the overall system and the simulation and experimental results of the prototype that was tested on a 4-cylinder engine in a production crossover vehicle
National concerns over energy consumption and emissions from the transportation sector have prompted regulatory agencies to implement aggressive fuel economy targets for light-duty vehicles through the U.S. National Highway Traffic Safety Administration/Environmental Protection Agency (EPA) Corporate Average Fuel Economy (CAFE) program. Automotive manufacturers have responded by bringing competitive technologies to market that maximize efficiency while meeting or exceeding consumer performance and comfort expectations. In a collaborative effort among Toyota Motor Corporation, Argonne National Laboratory (ANL), and the National Renewable Energy Laboratory (NREL), the real-world savings of one such technology is evaluated. A commercially available Toyota Highlander equipped with two-phase cold storage technology was tested at ANL’s chassis dynamometer testing facility. The cold storage technology maintains the thermal state of air-conditioning evaporators to enable longer and more
Electronic Stop-Start (ESS) system automatically stops and restarts the engine to save energy, improve fuel economy and reduce emissions when the vehicle is stationary during traffic lights, traffic jams etc. The stop and start events cause unwanted vibrations at the seat track which induce discomfort to the driver and passengers in the vehicle. These events are very short duration events, usually taking less than a second. Time domain analysis can help in simulating this event but it is difficult to see modal interactions and root cause issues. Modal transient analysis also poses a limitation on defining frequency dependent stiffness and damping for multiple mounts. This leads to inaccuracy in capturing mount behavior at different frequencies. Most efficient way to simulate this event would be by frequency response analysis using modal superposition method. In order to do the same, there is a major hurdle which is due to the nature of the signal being highly transient and of short
Wire and cable products progress through a series of handling or operational steps from the time they leave the manufacturer, and until a finished harness or assembly is ready for installation on a vehicle. Throughout these many steps, environmental or processing conditions may be present which can generate damage detrimental to the wire or cable and/or its intended application
To achieve accuracy in model development with large-scale actual customer data in low cost and limited time usage of telematics system was adopted. Honda’s OBD II diagnostic connecting device Honda Connect was used as transceiver for this telematics system, which was used as an accessory in Honda vehicles. Data collected with this device with large sample size and regional diversity across India was used in product development for Honda System. Control system development for BSVI vehicles, Idle start stop hardware specification selection and Battery electric vehicle target range study was done with Honda Connect Data
Hybridization of off road vehicles is in its early phase but it is likely to increase in coming years. In order to improve fuel economy and overall emission of the 3.3 litre tractor model, various kinds of engine hybridization is studied. This paper presents a methodology to predict vehicle fuel consumption and emission using 1-D software by coupling Ricardo Wave and Ricardo Ignite. Initially, An acceptable agreement within 5% deviation between simulation and experimental is established for engine steady state points, both for engine performance and NOx emission parameters. Engine fuel consumption and emission maps are predicted using Ricardo WAVE model. These maps are used as an input to IGNITE model for predicting cumulative fuel consumption. Same calibrated model is used further for studying idle start stop and fully hybrid P0 type hybrid architecture. The hybrid P0 type involves idle start stop, e-boost and regeneration. Model predicts overall significant reduction in cumulative
This paper presents an investigation of drivability issue of engine start-stop. Hybrid vehicles provide excellent benefits regarding fuel efficiency and emission. However, vibration results from constant engine start and stop events generate drivability issues, thus compromising driving comfort. This paper has designed a high speed torque sensor to capture instantaneous torque at the engine shaft. Its consequences help to find out the most suitable index of vibration severity. This paper is organized in four sections. The first section introduces the powertrain to be studied. The second section introduces development of a specially designed torque sensor. The torque sensor is installed between the engine and ISG (Integrated Starter Generator), alongside with an encoder. The torque sensor is utilized to collect the instantaneous shaft torque on occasion of engine start. In the third section, this paper has performed two experiments. Firstly, a typical engine start process (from 0 to 650
Until 2017 in Europe the Type Approval (TA) procedure for light duty vehicles for the determination of pollutant emissions and fuel consumption was based on the New European Driving Cycle (NEDC), a test cycle performed on a chassis dynamometer. However several studies highlighted significant discrepancies in terms of CO2 emissions between the TA test and the real world, due to the limited representativeness of the test procedure. Therefore, the European authorities decided to introduce a new, up-to date, test procedure capable to closer represent real world driving conditions, called Worldwide Harmonized Light Vehicles Test Procedure (WLTP). This work aims to analyze the effects of the new WLTP on vehicle CO2 emissions through both experimental and simulation investigations on two different Euro 5 vehicles, a petrol and a diesel car, representatives of average European passenger cars. The study also considers the effect of the engine warm-up and the impact of the start-stop technology
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