Browse Topic: Starters and starting
As the global energy transition moves to increased levels of electrification for passenger cars, then the number and role of hybrid electric vehicles (HEVs) increases rapidly. For these, the power reaches the road from an internal combustion engine (ICE) and/or an electric motor, with several switches between these three modes, over a typical drive-cycle. Consequently, this comes with a large increase in the number of significant engine stop and start events. Such events are potentially challenging for the HEV engine lubricant, as by comparison, for standard ICE cycles there is almost continuous relative movement of the two lubricated surfaces, for most areas of the engine. Based on both field and test cell observations, a challenging area for the lubricant within the gasoline direct injection (GDI) engine is the high pressure (HP) fuel pump, typically driven by a cam and follower, whilst lubricated by engine oil. From engine start, the speeds are low, also the fuel pump loads are high
In cost- effective P2 hybrid vehicles with low voltage electric machines connected to the engine, an interesting control problem arises during the transition to a locked driveline state. This occurs when the engine connects to the wheels via a separation clutch. The two primary torque sources, the engine and the clutch, are traditionally imperfect estimators of applied and transferred torques. The Hybrid Supervisor’s feedforward constraints model relies on these imperfect inputs to determine torque and acceleration limits for the engine’s desired acceleration profiles and to specify engine feedforward commands, aiming for synchronization speed. Due to the inaccuracies in the torque estimates of the engine and clutch, the Hybrid Supervisor is susceptible to control windup, increased jerk to the driveline during synchronization, and inaccurate computation of its target acceleration profile, speed, and torque targets for the engine to achieve synchronization speed. This paper presents a
Opening a tailgate can cause rain that has settled on its surfaces to run off onto the customer or into the rear loadspace, causing annoyance. Relatively small adjustments to tailgate seals and encapsulation can effectively mitigate these effects. However, these failure modes tend to be discovered relatively late in the design process as they, to date, need a representative physical system to test – including ensuring that any materials used on the surface flow paths elicit the same liquid flow behaviours (i.e. contact angles and velocity) as would be seen on the production vehicle surfaces. In this work we describe the development and validation of an early-stage simulation approach using a Smoothed Particle Hydrodynamics code (PreonLab). This includes its calibration against fundamental experiments to provide models for the flow of water over automotive surfaces and their subsequent application to a tailgate system simulation which includes fully detailed surrounding vehicle geometry
Hydrogen internal combustion engines (H2-ICE) do not emit any fuel-borne carbon emission species. Nitrogen oxides are the remaining raw emission species at significant levels. However, the exhaust aftertreatment system is exposed to a different exhaust matrix, including unburned hydrogen. This raises the question of the role of hydrogen emissions for the aftertreatment system. Extensive synthetic gas bench (SGB) test campaigns address the role of hydrogen in several production catalyst components. Starting with selective catalytic reduction (SCR) systems, a systematic variation of the hydrogen concentration shows rather small effects on the NOX reduction performance. A change in selectivity results in increased secondary N2O emissions for a copper-zeolite system, whereas a vanadium-based SCR catalyst is unaffected. However, both SCR types are highly sensitive to the NO2/NOX ratio in the raw emission. Therefore, an upstream oxidation catalyst remains important for low temperature
Battery cell aging and loss of capacity are some of the many challenges facing the widespread implementation of electrification in mobility. One of the factors contributing to cell aging is the dissimilarities of individual cells connected in a module. This paper reports the results of several aging experiments using a mini-module consisting of seven 5 Ah 21700 lithium-ion battery cells connected in parallel. The aging cycle comprised a constant current-constant voltage charge cycle at a 0.7C C-rate, followed by a 0.2C constant current discharge, spanning the useful voltage range from minimum to maximum according to the cell manufacturer. Charge and discharge events were separated by one-hour rest periods and were repeated for four weeks. Weekly reference performance tests were executed to measure static capacity, pulse power capability and resistance at different states of charge. All diagnostics were normalized with respect to their starting numbers to achieve a percentage change
This SAE Standard describes guarding to help prevent hazardous machine movement caused by activation of the starter motor by bypassing the starter control system. This document is applicable to off-road, self-propelled work machines, as identified in SAE J1116, and agricultural tractors, as defined in ANSI/ASAE S390, which have the potential for hazardous machine movement as a result of bypassing the starter control system and powering of the starter motor.
Recently, as part of the effort to enhance fuel efficiency and reduce costs for eco-friendly vehicles, the R-gearless system has been implemented in the TMED (P)HEV system. Due to the removal of the reverse gear, a distinct backward driving method needs to be developed, allowing the Electronic Motor (e-Motor) system to facilitate backward movement in the TMED (P)HEV system. However, the capability of backward driving with the e-Motor is limited because of partial failure in the high-voltage system of an R-gearless system. Thus, we demonstrate that it is possible to improve backward driving problems by applying a new fail-safe strategy. In the event of a high-voltage battery system failure, backward driving can be achieved using the e-Motor with constant voltage control by the Hybrid Starter Generator (HSG), as proposed in this study. The introduction of feed-forward compensation for variable constant voltage control allows for the securement of more active output power within the
In this paper, we present a novel algorithm designed to accurately trigger the engine coolant flow at the optimal moment, thereby safeguarding gas-engines from catastrophic failures such as engine boil. To achieve this objective, we derive models for crucial temperatures within a gas-engine, including the engine combustion wall temperature, engine coolant-out temperature, engine block temperature, and engine oil temperature. To overcome the challenge of measuring hard-to-measure signals such as engine combustion gas temperature, we propose the use of new intermediate parameters. Our approach utilizes a lumped parameter concept with a mean-value approach, enabling precise temperature prediction and rapid simulation. The proposed engine thermal model is capable of estimating temperatures under various conditions, including steady-state or transient engine performance, without the need for extra sensors. Moreover, it exhibits greater robustness compared to temperature estimation systems
The recommended practice describes a design standard that defines the maximum recommended voltage drop of the starting motor main circuits, as well as control system circuits, for 12/24-V starter systems. The battery technologies used in developing this document include the flooded lead acid, gel cell, and AGM. Starting systems supported by NiCd, Lithium Ion, NiZn, etc., or Ultracaps are not included in this document. This document is not intended to be updated or modified to include starter motors rated at voltages above the nominal 24-V electrical system. The starter is basically an electrical-to-mechanical power converter. If you double the available battery power in, you double the peak mechanical power out and double the heat losses. This means that we have to pay special attention to how battery power changes when we change the battery voltage and the effects it may have in overpowering the cranking system. A new stand-alone document would need to be developed to address
Automobiles are incorporated with advanced technologies to improve riding experience, safety, and vehicle management. Considering riding experience, major concern prevails in starting and charging system. For quick start and stop, implemented Integrated Starter Generator (ISG) in two wheelers. The ISG system consists of an ISG machine and ISG controller. ISG machine acts as motor during cranking and generator during charging, controlled by ISG controller. Automation kit is made with the help of real sensors, actuators, and microcontroller to monitor and log the performance characteristics of ISG system during te sting in rig level. Sensors continuously monitor the performance parameters and once the parameters are not meeting the specification, actuators stop the testing and raise the indication. All tested data are stored in cloud and taken for analysis. This automation kit served two purposes. One is eliminated test running on the failure sample for full long testing duration. Second
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.
Teleo announced that Florida-based Tomahawk Construction will become the first customer to deploy its autonomous capabilities on an active jobsite. Starting in December, Tomahawk Construction's articulated dump trucks will use autonomous functions to move material to build a residential community in Naples, Florida. Teleo also announced deals with eight new construction customers, including Ajax Paving Industries in Florida. The new customers have placed orders for 42 machines to be retrofitted with Teleo's autonomous and remote-operated technology. In addition, the tech company expanded its global dealer partner network to include Ozark Laser, Murphy Tractor and Position Partners. The expanded network covers an additional seven states across the U.S. Midwest and in Australia.
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