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The environment is one of the most important issues currently facing the world and the automobile industry is required to respond with eco-cars. To meet this requirement, the hybrid vehicle is one of the most optimal solutions. The hybrid system automatically stops engine idling (idling stop), or stops the engine during deceleration to recover energy. The engine stop however creates a problem concerning the vehicle's climate control system. Because the conventional climate control system incorporates a compressor driven by engine belt, there is almost no cooling performance while the engine is stopped. Until now, when a driver needed more cooling comfort the engine has been switched back on as a compromise measure. To realize cabin comfort that is consistent with fuel saving, a 2-way driven compressor has been developed that can be driven both by engine belt while the engine is running and by electric motor when the engine is stopped.

This paper presents a custom integrated circuit (IC) on which circuit functions necessary for “Active Hydraulic Brake (AHB) system” are integrated, and its key component, “Current-to-Digital Converter” for solenoid current measurement. The AHB system, which realizes a seamless brake feeling for Antilock Brake System (ABS) and Regenerative Brake Cooperative Control of Hybrid Vehicle, and the custom IC are installed in the 4th-generation Prius released in 2015. In the AHB system, as linear solenoid valves are used for hydraulic brake pressure control, high-resolution and high-speed sensing of solenoid current with ripple components due to pulse width modulation (PWM) is one of the key technologies. The proposed current-to-digital converter directly samples the drain-source voltage of the sensing DMOS (double-diffused MOSFET) with an analog-to-digital (A/D) converter (ADC) on the IC, and digitizes it.

This paper provides a description of a newly developed dynamometer capable of measuring torque at speeds up to 90,000 rpm. The development which has been made enables the dynamometer to measure output of a small single shaft gas turbine engine without a speed reducing gear box. The unit consists of a high speed generator to absorb the power and a torque measuring device. Since the generator is a key component of this dynamometer, a substantial portion of this paper is devoted to describing the configuration of the generator and the design considerations, as well as its performance. The rotational speed of turbomachines is gradually being increased and will be accelerated further as ceramic materials are introduced. The subjects to be discussed here will, hopefully, be of some use when a torque measuring device for speeds over 100,000 rpm becomes necessary.

A very difficult problem exists regarding windshield shape, and that is to create a balance between aerodynamics and optical distortion. To assist in solving this problem, this study, concerning the characteristics of visual perception for the optical distortion when drivers receive visual information through a windshield, was carried out. In this study, the windshield area was divided into 4 zones from the viewpoints of the level of drivers' fixation frequency and types of objects observed. Distortion was defined as the gap angle ( distortion angle ), which crossed the lines of a grid board with and without a windshield, and distortion angles were measured on a total of 4 windshields. Four drivers indicated areas in each windshield in which they felt the area was distorted. As a result, the thresholds of optical distortion were shown as a function of the horizontal and vertical distortion angles by discriminatory analysis.

Future Automotive Systems Technology Simulator (FASTSim) is a free and open-source tool developed by National Renewable Energy Lab (NREL). Among the attractive capabilities of the FASTSim is that it can perform computationally efficient fuel economy simulations of automotive vehicles with reasonable accuracy for standard or arbitrary drive cycles. The modeling capability includes vehicles with various types of powertrains such as: conventional vehicles (CVs), hybrid-electric vehicles (HEVs), plugin hybrid electric vehicles (PHEVs) and battery-only electric vehicles (BEVs). The public version of FASTSim available from NREL is implemented in Excel, which achieves the goal of good accessibility to a broad audience, but has some limitations, including: i) bottleneck in computations when importing arbitrary drive cycles, ii) slower computations in general than other scripting or programming languages, and iii) less portable to integration with other applications and/or other platforms.

In the field of automotive body electronic control such as control of door locks, power windows, and wipers, there is a growing need of multiplexing communication to reduce the amount of wire harnesses. To meet this need, we developed a multiplexing communication protocol particularly suited to the body electronic control. Based on the developed protocol, we designed a communication control IC and a simple driver/receiver circuit with a few discrete components. The bus access method of the communication is the CSMA/CD with nondestructive bit arbitration, and its bit rate is 5 kbps. Its transmission media is a single wire. The communication IC has a multiplexing control block and a serial I/O block for an interface with a host CPU. It was fabricated using CMOS technology and has a chip of 2.6mm x 3.0mm in size that contains about 5,000 transistors. The driver/receiver circuit consists of one transistor, one capacitor and several resistors.

A new 4.5 liter in-line 6 cylinder engine,1 FZ-FE has been developed for the Toyota Land Cruiser. To obtain high power, fuel efficient engine, we adopted the most advanced Toyota technologies, such as Toyota original 4 Valve DOHC system with scissors gear between camshafts, compact combustion chamber with smooth inlet and outlet system, KCS and so on. The engine produces 212 HP at 4600 rpm and 275 ft-lbs at 3200 rpm. Aluminum cylinder head,short skirt cylinder block stiffened with aluminum oil pan give the engine light weight and make it rigid enough to have low vibration and quietness. And we also designed every engine part appropriately so as to make the engine durable enough in severe operating condition of off-road vehicle.

Development of a new battery system for Toyota Estima Hybrid, the world's first minivan hybrid vehicle, has been completed. The battery pack that consists of 30 nickel metal hydride battery modules is compactly arranged under the 3rd seat in the cabin along with components such as the battery cooling blower and the ducts. This arrangement was designed in consideration of user's vehicle use, passengers' comfort and efficient battery-cooling performance.

A new 4.0 liter V8 engine, 1UZ-FE, has been developed for the luxury sedan, LEXUS LS400. The engine has 4 camshafts and 32 valves, and weighs only 195 kg (430 lbs) having many light alloy components and carefully designed configurations. The appropriate engine displacement and high technology adopted throughout from design to manufacturing process enable the LS400 to run powerfully with excellent fuel economy and a pleasant sounds. It develops 250HP at 5600 rpm and 260ft-lbs of torque at 4400 rpm, and its fuel economy figure, well exceeds the EPA's tax charge level of 22.5mpg. These figures have been achieved through the newest technologies applied to every part of the design, such as: Well studied intake and exhaust systems, centrally located spark plug in the TOYOTA original four-valve combustion chamber, which has a narrow valve including angle, and low friction components like aluminum alloy valve lifters and well balanced moving parts.

To meet the requirements for higher horsepower and torque as well as lower fuel consumption and emissions, we have developed a new “Intelligent Variable Valve Timing (VV-i)” system. It gives continuously variable intake cam phasing by up to 60 degrees crank angle (CA) . This system not only increases WOT output by optimizing intake valve closing timing but also reduces fuel consumption and NOx/ HC emissions under part load by increasing intake and exhaust valve overlap on 4 stroke Spark Ignited engines. VVT-i has been applied to optimize a new 3-liter inline 6 engine for higher torque and at the same time better fuel economy with continuous and wide-range cam phasing.

A silicon micromachined gyroscope (angular rate sensor, yaw rate sensor) and accelerometer for vehicle stability control system is presented. The 5.1mm×4.7mm sensor chip is fabricated with a silicon micromachining process using a SOI (Silicon on Insulator) silicon wafer and a deep reactive ion etching. The sensor chip has a pair of resonators which are mechanically coupled and function as a tuning fork. The resonators are driven by electrostatic force and their movements are detected by capacitively sensing angstrom displacements. This sensor chip works not only as a gyroscope but also as an accelerometer with a single sensor chip. The sensor unit consists of the sensor chip above, a signal processing IC, a microcomputer and an EEPROM. sigma-delta analog-to-digital conversion (sigma-delta ADC) is adopted to realize the digital calibration of sensor properties.

A new experimental method, that enables to estimate the body and driveline sensitivity to unit transmitting error of a hypoid gear for automotive rear axle gear noise, has been developed. Measurements were made by exciting the tooth of the drive-pinion gear and that of the ring gear separately using the special devices designed with regard to simulation of acceleration and deceleration. The characteristic of this method is to estimate the forces at the contact point of the gears. Estimation of these forces is carried out under the condition that the higher stiffness is provided by the tooth of the drive-pinion gear and that of the ring gear, compared with the stiffness of the driveshafts and that of the propeller shaft etc., and relative angular displacement of the torsional vibration between the teeth of the drive-pinion gear and those of the ring gear is constant.

A laboratory scale simulation test method was developed to evaluate deterioration of radial lip seals of fluoroelastomer (FKM) compounds for engine crankshafts. The investigation of the collected radial lip seals of FKM compounds from the field with service up to 450,000km indicated that the only symptom of deterioration is a decrease of lip interference. This deterioration was not duplicated under conventional test conditions using an oil seal test machine because sludge build up at the seal lip caused oil leakage. However, revised test conditions make it possible to duplicate the deterioration experienced in the field. An immersion test using a radial lip seal assembled with the mating shaft was newly developed. This test method was found to be useful to evaluate deterioration of radial lip seals using FKM compounds. Oil additives affect the deterioration of lip seal materials significantly. Therefore, immersion tests of four different oils were conducted to evaluate this effect.

Many efforts have been made to understand the mechanism of whiplash injury. Recently, the cervical facet joint capsules have been focused on as a potential site of injury. An experimental approach has been taken to analyze the vertebral motion and to estimate joint capsule stretch that was thought to be a potential cause of pain. The purpose of this study is to analyze the kinematics of the cervical facet joint using a human FE model in order to better understand the injury mechanism. The Total Human Model for Safety (THUMS) was used to visually analyze the local and global kinematics of the spine. Soft tissues in the neck were newly modeled and introduced into THUMS for estimating the loading level in rear impacts. The model was first validated against human test data in the literature by comparing vertebrae motion as well as head and neck responses. Joint capsule strain was estimated from a maximum principal strain output from the elements representing the capsule tissues.

This paper analyzed the mechanisms of injury in high speed, right-lateral impacts of stock car auto racing, and interaction of the occupant and the seat system for the purpose of reducing the risk of injury, primarily rib fractures. Many safety improvements have been made to stock car racing recently, including the Head and Neck Support devices (HANS®), the 6-point restraint harnesses, and the implementation of the SAFER Barrier. These improvements have contributed greatly to mitigating injury during the race crash event. However, there is still potential to improve the seat structure and the understanding of the interaction between the driver and the seat in the continuation of making racing safety improvements. This is particularly true in the case of right-lateral impacts where the primary interaction is between the seat supports and the driver and where the chest is the primary region of injury.

Electric drive vehicles (EDV) have the potential to greatly reduce greenhouse gas (GHG) emissions and thus, there are many policies in place to encourage the purchase and use of gasoline-hybrid, battery, plug-in hybrid, and fuel cell electric vehicles. But not all vehicles are the same, and households use vehicles in very different ways. What if policies took these differences into consideration with the goal of further reducing GHG emissions? This paper attempts to answer two questions: i) are there certain households that, by switching from a conventional vehicle to an EDV, would result in a comparatively large GHG reduction (as compared to other households making that switch), and, if so, ii) how large is the difference in GHG reductions? The paper considers over 65,000 actual GPS trip traces (generated by one-second interval recording of the speed of approximately 2,900 vehicles) collected by the 2013 California Household Travel Survey (CHTS).

Posterior translation of the tibia with respect to the femur can stretch the posterior cruciate ligament (PCL). Fifteen millimeters of relative displacement between the femur and tibia is known as the Injury Assessment Reference Value (IARV) for the PCL injury. Since the anterior protuberance of the tibial plateau can be the first site of contact when the knee is flexed, the knee bolster is generally designed with an inclined surface so as not to directly load the projection in frontal crashes. It should be noted, however, that the initial flexion angle of the occupant knee can vary among individuals and the knee flexion angle can change due to the occupant motion. The behavior of the tibial protuberance related to the knee flexion angle has not been described yet. The instantaneous angle of the knee joint at the timing of restraining the knee should be known to manage the geometry and functions of knee restraint devices.

To meet the requirement for higher performance engine bearings, the microgrooved bearings, that is the plain bearings with shallow circumferential grooves, have been developed. Recently, the performance of microgrooved bearings obtained experimentally have reported1)2). The authors calculated the bearing performance of the microgrooved bearings by elastohydrodynamic lubrication theory. In this paper, the authors described thecalculation method and the performance of the microgrooved bearings obtained theoretically.

Brake squeal is a phenomenon of self-induced vibration of the brake components during braking. There are many kinds of brake squeal cases whose mechanisms require acting on a various number of potential root causes. Brake squeal phenomena can be generally separated into 2 main mode types related to the direction of disc vibration involved: in-plane mode and out-of-plane mode. For out-of-plane mode, a number of existing countermeasures can be potentially applied after characterization of the squeal occurrence condition by direct experiment or simulation analysis[1,2,3,4]. However, as there are many possible mechanisms and root causes for the in-plane modes[5,6,7,8,9,10,11,12,13], it is generally necessary to perform a detailed analysis of the vibration mechanism before implementing a countermeasure.

Whinning gear noise(final gear noise), one of the causes for automobile interior noise is due to the exciting force of final gear kit and as a general countermeasure for this problem, a reduction of resonance level in transfer system and better meshing of gears have been utilized. However,vibration characteristics of final gear unit have not been considered much in this case. Authors have executed impacting test on final gear unit and confirmed its vibration characteristics. Based on this fact,vibration model consisting of bearings and gears spring system was constructed to evaluate vibration characteristics of final gear unit along with the results obtained from final gear unit of front engine,rear drive passenger car.