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The Ford Ranger will be a domestically built, small pickup truck engineered to many design objectives typical of a fullsize pickup, yet with four cylinder engine fuel efficiency. Ranger is a full-function on-and-off road pickup truck with a uniquely smooth ride and a capacity to carry up to a 725.7 kg. (1600 lb.) payload. The truck features a three passenger body-on-frame cab and a double wall pickup box with provision for 1.2m × 2.4m (4 ft. × 8 ft.) sheets of construction material. Featured in this comprehensive paper are the engineering highlights and innovations contributing to the accomplishment of these Small Truck objectives.

The High Voltage Power Distribution Unit (PDU) is constructed of magnesium in support of Fuel Cell Electric Vehicle (FCEV) weight reduction efforts. The PDU distributes and controls a nominal 75 kilowatts of power generated by the Fuel Cell, the primary source of High Voltage power, to all the vehicle loads and accessories. The constraints imposed on the design of the PDU resulted in a component highly susceptible to general and galvanic corrosion. Corrosion abatement was the focus of the PDU redesign. This paper describes the redesign efforts undertaken by Ford personnel to improve the part robustness and corrosion resistance.

Ford Motor Company has recently implemented a Hardware-In-the-Loop (HIL) testing system for a new, highly complex, hybrid electric vehicle (HEV) Electronic Control Unit (ECU). The implementation of this HIL system has been quick and effective, since it is based on proven Commercial-Off-The-Shelf (COTS) automation tools for real-time that allow for a very flexible and intuitive design process. An overview of the HIL system implementation process and the derived development benefits will be shown in this paper. The initial concept for the use of this HIL system was a complete closed-loop vehicle simulation environment for Vehicle System Controller testing, but the paper will show that this concept has evolved to allow for the use of the HIL system for many facets of the design process.

In future vehicles (e.g. fuel cell vehicles, hybrid electric vehicles), the electrical system will have an important impact on the mechanical systems in the car (e.g. powertrain, steering). Furthermore, this coupling will become increasingly important over time. In order to develop effective designs and appropriate control systems for these systems, it is important that the plant models capture the detailed physical behavior in the system. This paper will describe models of two electrical components, a battery and a supercapacitor, which have been modeled in two ways: (i) modeling the plant and controller using block diagrams in Simulink and (ii) modeling the plant and controller in Dymola followed by compiling this model to an S-function for simulation in Simulink. Both the battery and supercapacitor model are based on impedance spectroscopy measurements and can be used for highly dynamic simulations.

Three pickup truck variants of the Generic Truck Utility (GTU) are evaluated and compared using wind tunnel test data and computational fluid dynamics (CFD) simulations. The configurations analyzed are the short cab/long box, medium cab/medium box, and long cab/short box geometries, which all share a common vehicle length and wheelbase. Both cab and box length are known to influence the total bluff body drag through the interaction of the cab wake in the pickup box with the total vehicle wake, and the GTU provides an excellent test box to investigate the details of these interactions. Experimental testing was conducted at the WindShear wind tunnel on a full-scale GTU model, while transient CFD simulations were carried out with IconCFD®, an open-source based solver. Experimental and CFD results are used to describe the general flow field around the vehicle, and a comparison is made with the wind tunnel integral force data as well as centerline pressure tap data.

Brake squeal has been a chronic customer complaint, often appearing high on the list of items that reduce customers' satisfaction with their vehicles. Brake squeal can emanate from either a drum brake or a disc brake even though the geometry of the two systems is significantly different. A drum brake generates friction within a cylindrical drum interacting with two semi-circular linings. A disc brake consists of a flat disc and two flat pads. The observed squeal behavior in a vehicle differs somewhat between drum and disc brakes. A drum brake may have a loud noise coming from three or more squeal frequencies, whereas a disc brake typically has one or two major squeal frequencies making up the noise. A good understanding of the operational deflection shapes of the brake components during noise events will definitely aid in design to reduce squeal occurrences and improve product quality.

In this study the finite element method is used to simulate a light truck multi-leaf spring system and its interaction with a driven axle, u-bolts, and interface brackets. In the first part of the study, a detailed 3-D FE model is statically loaded by fastener pre-tension to determine stress, strain, and contact pressure. The FE results are then compared and correlated to both strain gage and interface pressure measurements from vehicle hardware test. Irregular contact conditions between the axle seat and leaf spring are investigated using a design of experiments (DOE) approach for both convex and discrete step geometries. In the second part of the study, the system FE model is loaded by both fastener pre-tension and external wheel end loads in order to obtain the twist motion response. Torsional deflection, slip onset, and subsequent slip motion at the critical contact plane are calculated as a function of external load over a range of Coulomb friction coefficients.

Variant modeling techniques have been developed to allow systems engineers to model multiple similar variants in a product line as a single variant model. In this paper, we expand on this past work to explore the extent to which variant modeling in SysML can be applied to a broad range of dissimilar systems, covering the entire domain of ground vehicles, in single reference architecture model. Traditionally, a system’s structure is decomposed into subsystems and components. However, this method is found to be ineffective when modeling variants that are functionally similar but structurally different. We propose to address this challenge by first decomposing the system not only by subsystem but also by high-level function. This pattern is particularly useful for situations where two variants perform the same function, but one variant performs the function using one subsystem, whereas the other variant performs the same function using one or more different subsystems.

There are several reasons why it can be daunting to apply Six Sigma to product creation. Foremost among them, the functional performance of new technologies is unknown prior to starting a project. Although, Design For Six Sigma (DFSS) was developed to overcome this difficulty, a lack of applicable in-class case studies makes it challenging to train the product creation community. The current paper describes an in-class project which illustrates how Six Sigma is applied to a simulated product creation environment. A toy construction set (TCS) project is used to instruct students how to meet customer expectations without violating cost, packaging volume and design-complexity constraints.

Subjective steering feel tuning and objective verification tests are conducted on vehicle prototypes that are a subset of the total number of buildable combinations of body style, drivetrain and tires. Limited development time, high prototype vehicle cost, and hence limited number of available prototypes are factors that affect the ability to tune and verify all the possible configurations. A new model-based process and a toolset have been developed to enhance the existing steering development process such that steering tuning efficiency and performance robustness can be improved. The innovative method utilizes the existing vehicle dynamics simulation and/or physical test data in conjunction with steering system control models, and provides users with simple interfaces which can be used by either CAE or development engineers to perform virtual tuning of the vehicle steering feel to meet performance targets.

The transportation sector is facing three revolutions: shared mobility, electrification, and autonomous driving. To inform decision making and guide smart transportation system development at the city-level, it is critical to model and evaluate how travelers will behave in these systems. Two key components in such models are (1) individual travel demands with high spatial and temporal resolutions, and (2) travelers’ sociodemographic information and trip purposes. These components impact one’s acceptance of autonomous vehicles, adoption of electric vehicles, and participation in shared mobility. Existing methods of travel demand generation either lack travelers’ demographics and trip purposes, or only generate trips at a zonal level. Higher resolution demand and sociodemographic data can enable analysis of trips’ shareability for car sharing and ride pooling and evaluation of electric vehicles’ charging needs.

The performance of structure-borne road NVH can be cascaded down to three major systems: 1) vehicle body structure, 2) chassis/suspension, 3) tire/wheel. The forces at the body attachment points are controlled by the isolation efficiency of the chassis/suspension system and the excitation at the spindle/knuckle due to the tire/road interaction. The chassis force transmissibility is a metric to quantify the isolation efficiency. This paper presents a new experimental methodology to estimate the chassis force transmissibility from a fully assembled vehicle. For the calculation of the transmissibility, the spindle force/moment estimation and the conventional Noise Path Analysis (NPA) methodologies are utilized. A merit of the methodology provides not only spindle force to body force transmissibility but also spindle moment to body force transmissibility. Hence it enables us to understand the effectiveness of the spindle moments on the body forces.

Past studies have shown that NVH CAE tire model quality is not adequate to correctly capture a mid-frequency range (100-300 Hz). A new methodology has been developed to estimate tire forces that are independent of dynamic characteristics of vehicle suspension and rig test fixture. The forces are called tire blocked forces and defined as a force generated by a tire/wheel system whose boundary condition is constrained. The tire blocked force is estimated by removing the dynamic effect of the tire force measurement fixture. The blocked forces can be applied to CAE models to predict vehicle road NVH responses. This new method can also be used as a target setting tool. Tire suppliers can check the blocked tire forces from the rig testing data against a force target before they submit tires to automotive manufacturers for evaluations on a prototype vehicle.

Today's automotive and electronics technologies are evolving so rapidly that educators and industry are both challenged to re-educate the technological workforce in the new area before they are replaced with yet another generation. In early November 2009 Ford's Product Development senior management formally approved a proposal by the University of Detroit Mercy to transform 125 of Ford's “IC Engine Automotive Engineers” into “Advanced Electric Vehicle Automotive Engineers.” Two months later, the first course of the Advanced Electric Vehicle Program began in Dearborn. UDM's response to Ford's needs (and those of other OEM's and suppliers) was not only at the rate of “academic light speed,” but it involved direct collaboration of Ford's electric vehicle leaders and subject matter experts and the UDM AEV Program faculty.

Road loads tire models are used in the automotive industry in full vehicle simulations to compute the loading from the road into the chassis encountered in proving ground durability events. Such events typically include Belgian Block events, bump events, potholes and others. Correctly capturing tire enveloping forces in such events has historically been challenging - several different approaches exist each with its own limitations. In this paper a model is presented which captures the first order tire dynamics (frequencies lower than 80 Hz) and associated enveloping loading without the need of an effective road profile. The theory behind this tire model is briefly introduced. Importantly, a comprehensive study of the validation of the tire model is given which shows correlation for full vehicle dynamic proving ground events. A Virtual Tire Lab (VTL) pre-processing tool is also presented which is used to compute tire model input parameters from a validated non-linear FEA tire model.

SiC devices have inherent fast switching capabilities due to their superior material properties, and are considered potential candidates to replace Si devices for traction inverters in electrified vehicles in future. However, due to the comparatively low gate threshold voltage, SiC devices may encounter oscillatory false triggering especially during fast switching. This paper analyzed the causes of false triggering, and also studied the impact of a critical parasitic parameter - common source inductance. It is shown that crosstalk is the main cause for the false triggering in the case and some positive common source inductance help to mitigate the crosstalk issue. A packaging layout method is proposed to create the positive common source inductance through layout of control terminals / busbars, and/or the use of control terminal bonded wires at different height.

Explicit finite element simulations were conducted on an aluminum wheel model where a rotating bend moment was applied on its hub to simulate wheel cornering fatigue testing. A post-processor was developed to calculate equivalent von Mises alternating and mean stresses from stress tensor. The safety factors of fatigue design for each finite element were determined to assess the fatigue performance by utilizing the Goodman linear relationship. Elements with low safety factors were identified due to the prescribed boundary conditions and stress concentrations arising from wheel geometry.

The IGBTs are dominantly used in traction inverters for automotive applications. Because the Si-based device technology is being pushed to its theoretical performance limit in such applications during recent years, the gate driver design is playing a more prominent role to further improve the traction inverter loss performance. The conventional gate driver design in traction inverter application needs to consider worst case scenarios which adversely limit the semiconductor devices' switching speed in its most frequent operation regions. Specifically, when selecting the gate resistors, the IGBT peak surge voltage induced by fast di/dt and stray inductance must be limited below the device rated voltage rating under any conditions. The worst cases considered include both highest dc bus voltage and maximum load current. However, the traction inverter operates mainly in low current regions and at bus voltage much lower than the worst case voltage.

Plug in hybrid electric vehicles (PHEVs) have gained interest over last decade due to their increased fuel economy and ability to displace some petroleum fuel with electricity from power grid. Given the complexity of this vehicle powertrain, the energy management plays a key role in providing higher fuel economy. The energy management algorithm on PHEVs performs the same task as a hybrid vehicle energy management but it has more freedom in utilizing the battery energy due to the larger battery capacity and ability to be recharged from the power grid. The state of charge (SOC) profile of the battery during the entire driving trip determines the electric energy usage, thus determining overall fuel consumption.

Utilization of statistical methods can improve vehicle stopping-distance projections and reduce the complexity of brake deceleration models. These techniques can be very useful in the course of ascertaining whether an untested vehicle conforms to the applicable Federal Motor Vehicle Safety Standard (FMVSS), but they have much broader uses in the design of brake systems.