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The purpose of this paper is to find a way to extend the high load limit of homogeneous charge compression ignition (HCCI) combustion. This paper presents the effect of in-cylinder flow and stratified mixture on HCCI combustion by experiments and three-dimensional computer fluid dynamics coupled with a detailed chemical reaction calculation. The first study was conducted using a rapid compression and expansion machine (RCEM) equipped with a flow generation plate to create in-cylinder turbulent flow and with a control unit of in-cylinder wall temperature to create in-cylinder temperature distribution. The study assesses the effect of the turbulent flow and the temperature distribution on HCCI combustion. In the second study, the numerical simulation of HCCI combustion was conducted using large eddy simulation coupled with a detailed chemical reaction calculation. The study analyzes the interaction between in-cylinder turbulent flow and mixture distribution and HCCI combustion.

This paper studies the use of active rear steering (4-wheel steering) to change the transient lateral dynamics and body motion of passenger cars in the stable or linear region of the tires. Rear steering systems have been used for several decades to improve low speed turning maneuverability and high speed stability, and various control strategies have been previously published. With a model-based, feed-forward rear steer control strategy, the lateral transient can be influenced separately from the steady-state steering gain. This lateral transient is influenced by many vehicle parameters, but we will look at the influence of active rear steer and various tire types such as all-season, snow, and summer. This study will explore the ability for a rear steering system to change the lateral transient to a step steer input, compared to the effect of changing tire types.

Today, 99% of the two wheelers in India operate with carburetor based fuel delivery system. But with implementation of Bharath Stage VI emission norms, compliance to emission limits along with monitoring of components in the system that contributes towards tail pipe emissions would be challenging. With the introduction of the OBD II (On-Board Diagnostics) and emission durability, mass migration to electronically controlled fuel delivery system is very much expected. The new emission norms also call for precise metering of the injected fuel and therefore demands extended calibration effort. The calibration of engine management system starts with the generation of pre-calibration dataset capable of operating the engine at all operating points followed by base calibration of the main parameters such as air charge estimation, fuel injection quantity, injection timing and ignition angles relative to the piston position.

Brake pad to rotor adhesion following exposure to corrosive environments, commonly referred to as “stiction”, continues to present braking engineers with challenges in predicting issues in early phases of development and in resolution once the condition has been identified. The goal of this study took on two parts - first to explore trends in field stiction data and how testing methods can be adapted to better replicate the vehicle issue at the component level, and second to explore the impacts of various brake pad physical properties variation on stiction propensity via a controlled design of experiments. Part one will involve comparison of various production hardware configurations on component level stiction tests with different levels of prior braking experience to evaluate conditioning effects on stiction breakaway force.

The strong focus on reducing brake drag, driven by a historic ramp-up in global fuel economy and carbon emissions standards, has led to renewed research on brake caliper drag behaviors and how to measure them. However, with the increased knowledge of the range of drag behaviors that a caliper can exhibit comes a particularly vexing problem - how should this complex range of behaviors be represented in the overall road load of the vehicle? What conditions are encountered during coastdown and fuel economy testing, and how should brake drag be measured and represented in these conditions? With the Environmental Protection Agency (amongst other regulating agencies around the world) conducting audit testing, and the requirement that published road load values be repeatable within a specified range during these audits, the importance of answering these questions accurately is elevated. This paper studies these questions, and even offers methodology for addressing them.

Automotive systems can generate un-intentional radio frequency energy. The levels of these emissions must be below maximum values set by the Original Equipment Manufacturer (OEM) for customer satisfaction and/or in order to meet governmental requirements. Due to the complexity of electromagnetic coupling mechanisms that can occur on a vehicle, many times it is difficult to measure and identify the noise source(s) without the use of an electromagnetic interference (EMI) receiver or spectrum analyzer (SA). An efficient and effective diagnostic solution can be to use a low-cost portable, battery powered RF detector with wide dynamic range as an alternative for automotive electromagnetic compatibility (EMC) and design engineers to identify, locate, and resolve radio frequency (RF) noise problems. A practical circuit described here can be implemented easily with little RF design knowledge, or experience.

Anti-lock Braking Systems (ABS) for motorcycles have already contributed significantly to the safety of powered two-wheelers (PTW) on public roads by improving bike stability and controllability in emergency braking situations. In order to address further riding situations, another step forward has been achieved with Motorcycle Stability Control (MSC) system. By combining ABS, electronically combined braking system (eCBS), traction control and inertial sensors even in situations like braking and accelerating in corners the riders' safety can be improved. The MSC system controls the distribution of braking and traction forces using an algorithm that takes into account all available vehicle information from wheels, power train and vehicle attitude. With its ability to control fundamental vehicle dynamics, the MSC system will be a basis for further development and integration of comprehensive safety systems.

The Chevrolet Volt is an electric vehicle with extended-range that is capable of operation on battery power alone, and on engine power after depletion of the battery charge. First generation Chevrolet Volts were driven over half a billion miles in North America from October 2013 through September 2014, 74% of which were all-electric [1, 12]. For 2016, GM has developed the second-generation of the Volt vehicle and “Voltec” propulsion system. By significantly re-engineering the traction power inverter module (TPIM) for the second-generation Chevrolet Volt extended-range electric vehicle (EREV), we were able to meet all performance targets while maintaining extremely high reliability and environmental robustness. The power switch was re-designed to achieve efficiency targets and meet thermal challenges. A novel cooling approach enables high power density while maintaining a very high overall conversion efficiency.

This paper presents the work of the SAE Brake NVH Standards Committee in developing a draft Low-Frequency Brake Noise Test Procedure. The goal of the procedure is to be able to accurately measure noise issues in the frequency range below 900 Hz using a conventional shaft brake noise dynamometer. The tests conducted while evaluating alternative test protocols will be discussed and examined in detail. The unique issues encountered in developing a suitable test procedure for low-frequency noise will be discussed, and the results of tests using both shaft brake dynamometers and chassis dynamometers will be described. The current draft procedure incorporating the knowledge gained from this development effort will be described in detail and conclusions as to its applicability will also be presented

NVH development is an important part of modern brake product development plans. This paper analyzes a typical NVH development process and identifies gaps in available development technologies and processes that when filled can improve the brake NVH development effort. The paper also discusses how the disciplines of simulation, component testing, dynamometer testing, and vehicle testing are currently integrated and proposes more effective processes of development. The paper identifies opportunities for contributions from professional societies and standardization organizations, vendors of test equipment and software, test laboratories, university research centers as well as brake suppliers' engineering centers to improve the engineering toolbox and fill the gaps in brake NVH development.

As part of the development of a new SAE Recommended Practice for brake rotor modal frequencies measurement and control, the SAE Brake NVH Standards Committee developed detailed recommendations for such measurement, data reporting and use in quality control. This paper addresses the need for formalizing measurement techniques of rotor modal frequencies and documenting the proper set up and measurement parameters. Additionally, a rotor mode classification system is proposed so that important rotor modes may be tracked. Statistical control of modal frequencies is presented and practical limits are defined

The main purposes of the KB variant engine development were not only to reduce fuel consumption or to enhance reliability & quality but also to make better productivity for global manufacture. This paper introduces technical approaches of KB, higher thermal efficiency, better performance and emissions, and well balanced product design with such high energy efficiency, and low-cost and global application. Maximum brake torque per displacement is 7% higher and overall engine weight is lighter by 24kg than an existing 1.3L engine. Design feature includes compactness, low noise characteristics and universal production design considered with globally purchasable materials and simple manufacturing requirement. These contribute short production preparation period and short production task time at Suzuki's key overseas local factories e.g., Maruti Suzuki India Limited.

“Creep groan” is a braking systems noise that is observed when a vehicle is starting to move from a stopped condition with brake pressure applied. Motion takes place when brake pressure is reduced while a motive force, such as an idling engine through an automatic transmission, or gravity due to the vehicle being on a slope, is present. The vibration causing the sound is commonly thought to result from friction force variation in stick-slip mode. Detection and evaluation of “creep groan” noise has been a challenge for NVH test groups. First, this sound typically is not purely tonal like the more common brake squeal, although ultimately it may produce a tonal subjective impression. In this work the authors study different methods that may be applied to “creep groan” detection and evaluation.

Brake squeal is caused by the friction-induced vibration at the rotor/pad interfaces (primary contact interfaces) in a disc brake system. While there have been numerous research work evaluating the influence of primary contact interfaces on brake squeal, few studies can be found on the effect of the secondary contact interfaces, i.e., outer pad/caliper fingers, inner pad/pistons and pad/abutment, which can also significantly affect brake squeal based on our various dynamometer and vehicle tests. It is therefore the objective of this paper to investigate both the primary and the secondary contact interfaces and their influence on brake squeal. Simplified analytical models are created to gain insight into the stability of the brake system under low and high brake pressure; non-linear FEA analysis is employed for parametric study and countermeasure development; dynamometer and vehicle tests are used for verification.

Automotive engines are regularly utilized in the material handling market where LPG is often the primary fuel used. When compared to gasoline, the use of gaseous fuels (LPG and CNG) as well as alcohol based fuels, often result in significant increases in valve seat insert (VSI) and valve face wear. This phenomenon is widely recognized and the engine manufacturer is tasked to identify and incorporate appropriate valvetrain material and design features that can meet the ever increasing life expectations of the end-user. Alternate materials are often developed based on laboratory testing – testing that may not represent real world usage. The ultimate goal of the product engineer is to utilize accelerated lab test procedures that can be correlated to field life and field failure mechanisms, and then select appropriate materials/design features that meet the targeted life requirements.

The auto industry has had decades of experience with designing safe vehicles. The introduction of highly integrated features brings new challenges that require innovative adaptations of existing safety methodologies and perhaps even some completely new concepts. In this paper, we describe some of the new challenges that will be faced by all OEMs and suppliers. We also describe a set of generic top-level potential hazards that can be used as a starting point for the Preliminary Hazard Analysis (PHA) of a vehicle software-intensive motion control system. Based on our experience with the safety analysis of a system of this kind, we describe some general categories of hazard causes that are considered for software-intensive systems and can be used systematically in developing the PHA.

By adapting vehicle control systems to the skill level of the driver, the overall vehicle active safety provided to the driver can be further enhanced for the existing active vehicle controls, such as ABS, Traction Control, Vehicle Stability Enhancement Systems. As a follow-up to the feasibility study in [1], this paper provides some recent results on data-driven driving skill characterization. In particular, the paper presents an enhancement of discriminant features, the comparison of three different learning algorithms for recognizer design, and the performance enhancement with decision fusion. The paper concludes with the discussions of the experimental results and some of the future work.

Model-based design is a collection of practices in which a system model is at the center of the development process, from requirements definition and system design to implementation and testing. This approach provides a number of benefits such as reducing development time and cost, improving product quality, and generating a more reliable final product through the use of computer models for system verification and testing. Model-based design is particularly useful in automotive control applications where ease of calibration and reliability are critical parameters. A novel application of the model-based design approach is demonstrated by The Ohio State University (OSU) student team as part of the Challenge X advanced vehicle development competition. In 2008, the team participated in the final year of the competition with a highly refined hybrid-electric vehicle (HEV) that uses a through-the-road parallel architecture.

In racetrack conditions, brake systems are subjected to extreme energy loads and energy load distributions. This can lead to very high friction surface temperatures, especially on the brake corner that operates, for a given track, with the most available traction and the highest energy loading. Individual brake corners can be stressed to the point of extreme fade and lining wear, and the resultant degradation in brake corner performance can affect the performance of the entire brake system, causing significant changes in pedal feel, brake balance, and brake lining life. It is therefore important in high performance brake system design to ensure favorable operating conditions for the selected brake corner components under the full range of conditions that the intended vehicle application will place them under. To address this task in an early design stage, it is helpful to use brake system modeling tools to analyze system performance.

Over the past decade, the automotive industry has seen a rapid decrease in product development cycle time and an ever increasing need by original equipment manufacturers and their suppliers to differentiate themselves in the marketplace. This differentiation is increasingly accomplished by introducing new technology while continually improving the performance of existing automotive systems. In the area of automotive brake system design, and, in particular, the brake apply subsystem, an increased focus has been placed on the development of electrohydraulic apply systems and brake-by-wire systems to replace traditional pneumatic and hydraulic systems. Nevertheless, the traditional brake apply systems, especially vacuum-based or pneumatic systems, will continue to represent the majority of brake apply system production volume into the foreseeable future, which underscores the need to improve the performance and application of these traditional systems in passenger cars and light-trucks.