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A special vehicle dynamometer has been developed that allows engineers to evaluate driveline components and control algorithms for advanced, electrically-assisted drive systems on commercial vehicles. This dynamometer allows objective measurements of performance, fuel economy, and exhaust emissions, while the full vehicle is operated over a specified driving cycle. This system can be used to exercise the electric motor, engine, transmission and battery systems on Medium Duty Hybrid Trucks - in regeneration as well as power mode - all indoors and in a controlled, repeatable environment. This paper will provide descriptions of the operating goals, control features, and results of testing with this dynamometer. Once the various parameters have been optimized for fuel and emissions performance in this facility, the vehicle can be evaluated where it counts - on the road.

Diesel Cylinder Deactivation (CDA) has been shown in previous work to increase exhaust temperatures, improve fuel efficiency, and reduce engine-out NOx for engine loads up to 3 bar BMEP. The purpose of this study is to determine whether or not the turbocharger needs to be altered when implementing CDA on a diesel engine. This study investigates the effect of CDA on exhaust temperature, fuel efficiency, and turbocharger performance in a 15L heavy-duty diesel engine under low-load (0-3 bar BMEP) steady-state operating conditions. Two calibration strategies were evaluated. First, a “stay-hot” thermal management strategy in which CDA was used to increase exhaust temperature and reduce fuel consumption. Next, a “get-hot” strategy where CDA and elevated idle speed was used to increase exhaust temperature and exhaust enthalpy for rapid aftertreatment warm-up.

The automotive industry has seen accelerating demand for electrified transportation. While the complexity of conventional ICE vehicles has increased, the powertrain still largely consists of a mechanical system. In contrast, vehicle architectures in electrified transportation are a complex integration of power electronics, batteries, control units, and software. This shift in system architecture impacts the entire organization during new product development, with increased focus on high power electronic components, energy management strategies, and complex algorithm development. Additionally, product development impact extends beyond the vehicle and impacts charging networks, electrical infrastructure, and communication protocols. The complex interaction between systems has a significant impact on vehicle safety, development timeline, scope, and cost.

With the increasing demand for efficient & clean transport solutions, applications such as road transport vehicles, aerospace and marine are seeing a rise in electrification at a significant rate. Irrespective of industries, the main source of power that enables electrification in mobility applications like electric vehicles (EV), electric ships and electrical vertical take-off & landing (e-VTOL) is primarily a battery making it fundamentally a DC system. Fast charging solutions for EVs & e-VTOLs are also found to be DC in nature because of several advantages like ease of integration, higher efficiency, etc. Likewise, the key drivers of the electric grid are resulting in an energy transition towards renewable sources, that are also essentially DC in nature. Overall, these different business trends with their drivers appear to be converging towards DC power systems, making it pertinent.

An advanced variable valve actuation (VVA) system is characterized following end-of-life testing to enable fuel economy solutions for passenger car applications. The system consists of a switching roller finger follower (SRFF) combined with a dual feed hydraulic lash adjuster and an oil control valve that are integrated into a four cylinder gasoline engine. The SRFF provides discrete valve lift capability on the intake valves. The motivation for designing this type of VVA system is targeted to improve fuel economy by reducing the air pumping losses during part load engine operation. This paper addresses the durability of a SRFF for meeting passenger car durability requirements. Extensive durability tests were conducted for high speed, low speed, switching, and cold start operation. High engine speed test results show stable valvetrain dynamics above 7000 engine rpm. System wear requirements met end-of-life criteria for the switching, sliding, rolling and torsion spring interfaces.

With the advent of wide band gap semiconductor devices like SiC based MOSFETs/Diodes, there is a growing demand for utilizing electrical power instead of the conventional fuel-based power generation in both automotive and aerospace industry. In automotive/aerospace industry the focus on electrification has resulted in a need for sub-systems like inverters, power distribution units, motor controllers, DC-DC converters that actively utilize SiC based power electronics devices. To address the growing power density requirements for electronics in next generation product families, more efficient & reliable thermal management solution plays a critical role. The effective thermal management of the power electronics is also critical aspect to ensure overall system reliability. The conventional thermal management system (TMS) optimization targets heat sink/ cold plate design parameters like fin spacing, thickness, height etc. or sizing of the required cooling pump/fan.

Typical traction control systems based on brake intervention have the disadvantage of dissipating an amount of energy roughly equal to that spent in biasing the high-friction wheel. Fully locked differentials achieve the best possible longitudinal traction but, in situations such as slippery or split-friction (split-μ) surfaces, the lateral dynamics of the vehicle can be degraded and deviate from the driver's intended direction. This paper presents an active stability control strategy using electronic limited slip differentials to enhance the vehicle lateral dynamics while preserving longitudinal motion. The proposed control system includes stability enhancement of the traction control and yaw stability control. The stability-enhanced traction control is evaluated under the condition of straight-line full-throttle launching on a split-μ ice/snow surface. The experimental data show a significant stability improvement in a traction mode.

The use of electrical contacts in aerospace applications is crucial, particularly in connectors that transmit signal and power. Crimping is a widely preferred method for joining electrical contacts, as it provides a durable connection and can be easily formed. This process involves applying mechanical load to the contact, inducing permanent deformation in the barrel and wire to create a reliable joint with sufficient wire retention force. This study utilizes commercially available Abaqus software to simulate the crimping process using an explicit solver. The methodology developed for this study correlates FEA and testing for critical quality parameters such as structural integrity, mechanical strength, and joint filling percentage. A four-indenter crimping tool CAD model is utilized to form the permanent joint at the barrel-wire contact interfaces, with displacement boundary conditions applied to the jaws of the tool in accordance with MIL-C-22520/1C standard.

Commercial vehicles require continual improvements in order to meet fuel emission standards, improve diesel aftertreatment system performance and optimize vehicle fuel economy. Aftertreatment systems, used to remove engine NOx, are temperature dependent. Variable valve actuation in the form of cylinder deactivation (CDA) has been shown to manage exhaust temperatures to the aftertreatment system during low load operation (i.e., under 3-4 bar BMEP). During cylinder deactivation mode, a diesel engine can have higher vibration levels when compared to normal six cylinder operation. The viability of CDA needs to be implemented in a way to manage noise, vibration and harshness (NVH) within acceptable ranges for today’s commercial vehicles and drivelines. A heavy duty diesel engine (inline 6 cylinder) was instrumented to collect vibration data in a dynamometer test cell.

Recent studies have shown that hydraulic hybrid drivelines can significantly improve fuel savings for medium weight vehicles on stop-start drive cycles. In a series hydraulic hybrid (SHH) architecture, the conventional mechanical driveline is replaced with a hydraulic driveline that decouples vehicle speed from engine speed. In an effort to increase the design space, this paper explores the use of a fixed displacement checkball piston pump in an SHH driveline. This paper identifies the potential life-limiting components of a fixed displacement checkball piston pump and examines the likelihood of surface fatigue in the check valves themselves. Numerical analysis in ABAQUS software suggests that under worst case operating conditions, cyclic pressure loading will result in low-cycle plastic deformation of check valve surfaces.

Automated clutches for vehicle startup is being increasingly deployed in commercial trucks for benefits, which include driver comfort, gradient performance, improved clutch life, emissions and driveline vibration reduction potential. The process of designing the controller is divided into 2 parts. Firstly, the parameter estimation of previously developed driveline models is carried out. The procedure involves an off-line minimization technique based on measured and estimated speeds. Secondly, the nominal plant model is used to develop LQR based optimal control strategy, which takes into account the slip time, dissipated power and slip acceleration. Mathematical expression of the performance index is clearly developed. A variety of clutch lock up profiles can be incorporated by changing a single tuning parameter, thus providing the driver the ability to select a launch profile based on specific driving objectives.

Large-scale flows in internal combustion engines directly affect combustion duration and emissions production. These benefits are significant given increasingly stringent emissions and fuel economy requirements. Recent efforts by engine manufacturers to improve in-cylinder flows have focused on the design of specially shaped intake ports. Utility engine manufacturers are limited to simple intake port geometries to reduce the complexity of casting and cost of manufacturing. These constraints create unique flow physics in the engine cylinder in comparison to automotive engines. An experimental study of intake-generated flows was conducted in a four-stroke spark-ignition utility engine. Steady flow and in-cylinder flow measurements were made using three simple intake port geometries at three port orientations. Steady flow measurements were performed to characterize the swirl and tumble-generating capability of the intake ports.

The three parameter Ramberg-Osgood (RO) method finds popular usage for extracting complete stress-strain curve from limited data which is usually available. The currently popular practice of assuming the plasticity to set in only at the Yield point provides computational advantage by separating the complete nonlinear curve, obtained from RO method, into elastic and plastic regions. It is shown, with an example problem, that serious errors are committed by using this method if one compares the obtained results with results of complete stress-strain curve. In the present work we propose a simple Taylor series based approach based on RO method to overcome the above deficiency. This method is found to be computationally efficient. The proposed method is applicable for stress-strain curves of materials for which RO method provides a good approximation.

ADVISOR is a flexible drivetrain analysis tool, developed in MATLAB/Simulink® to compare fuel economy and emissions performance between different drivetrain configurations. This paper reports a couple of numerical issues with application of ADVISOR 2002 to commercial vehicles with traditional powertrain systems. One instance is when ADVISOR model is set up to simulate running a heavy-duty (HD) truck with an automated manual transmission (AMT) on a demanding pickup-delivery duty cycle. The other is highlighted during an analysis of a medium-duty (MD) truck with an automatic transmission (AT) where wide-open throttle, i.e., fast acceleration is requested. These two cases have shown different numerical difficulties by using ADVISOR 2002. Based on studying the details of the models, solutions to these numerical issues are developed. The simulation results will demonstrate the effectiveness of these solutions.

This paper presents the modeling of an Electromagnetic Valve Actuator (EMV). A nonlinear model is formulated and presented that takes into account secondary nonlinearities like hysteresis, saturation, bounce and mutual inductance. The uniqueness of the model is contained in the method used in modeling hysteresis, saturation and mutual inductance. Theoretical and experimental methods for identifying parameters of the model are presented. The nonlinear model is experimentally validated. Simulation and experimental results are presented for an EMV designed and built in our laboratory. The experimental results show that sensorless estimation could be a possible solution for position control.

The Mississippi State University Formula SAE race car upright was optimized using radial basis function metamodels and an internal state variable (ISV) plasticity damage material model. The weight reduction of the upright was part of a goal to reduce the weight of the vehicle by 25 percent. Using an optimization routine provided an upright design that is lighter that helps to improve vehicle fuel economy, acceleration, and handling. Finite element (FE) models of the upright were produced using quadratic tetrahedral elements. Using tetrahedral elements provided a quick way to produce the multiple FE models of the upright required for the multi-objective optimization. A design of experiments was used to determine how many simulations were required for the optimization. The loads for the simulations included braking, acceleration, and corning loads seen by the car under track conditions.

This paper presents an empirical dynamic model of a single spring electromagnetic solenoid actuator system, including bounce, temperature effects and coil leakage inductance. The model neglects hysteresis and saturation, the aim being to compensate for these uncertainties through estimator robustness. The model is validated for all regions of operation and there is a good agreement between model and experimental data. A nonlinear (sliding mode) estimator is developed to estimate position and speed from current measurements. Since the estimator makes use of only current measurement it is given the name sensorless. The estimator is validated in simulation and experimentally. The novelty in this paper lies in the fact that accurate state estimation can be realized on a simple linear model using a robust observer theory. Also, the formulations for leakage inductance and coil temperature are unique.

A simulation framework with a validated system model capable of estimating fuel consumption is a valuable tool in analysis and design of the hybrid vehicles. In particular, the framework can be used for (1) benchmarking the fuel economy achievable from alternate hybrid powertrain technologies, (2) investigating sensitivity of fuel savings with respect to design parameters (for example, component sizing), and (3) evaluating the performance of various supervisory control algorithms for energy management. Presenter Chinmaya Patil, Eaton Corporation

A simulation framework with a validated system model capable of estimating fuel consumption is a valuable tool in analysis and design of the hybrid vehicles. In particular, the framework can be used for (1) benchmarking the fuel economy achievable from alternate hybrid powertrain technologies, (2) investigating sensitivity of fuel savings with respect to design parameters (for example, component sizing), and (3) evaluating the performance of various supervisory control algorithms for energy management. This paper describes such a simulation framework that can be used to predict fuel economy of series hydraulic hybrid vehicle for any specified driver demand schedule (drive cycle), developed in MATLAB/Simulink. The key components of the series hydraulic hybrid vehicle are modeled using a combination of first principles and empirical data. A simplified driver model is included to follow the specified drive cycle.

Car hauler ramps have historically been hydraulically positioned via banks of manual control valves that provide limited operator visibility and flexibility. On some enclosed type haulers, manual valves are not feasible. An electro-hydraulic system has been developed utilizing on/off solenoid valve stacks. A handheld control unit with a membrane switch pad communicates with a valve interface module near each valve stack. The handheld unit and the interface modules each have microprocessor circuitry to provide intelligent distributed control. Self monitoring circuitry provides safety features and system diagnostics. Wiring harness assemblies connect the valve stacks to the interface modules. A retractile cable from the handheld unit to the trailer allows improved operator mobility and visibility. An infrared wireless interface between the trailer and handheld unit will also be available.