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Technical Paper

A Study of Additive Effects on ATF Frictional Properties Using New Test Methods

A new test machine has been developed which can evaluate vibration due to stick-slip using an actual full-scale clutch pack. Using this machine, a static breakaway friction coefficient measurement test method and a stick-slip test method have been established. Both methods have been shown to provide results which correlate with the results from both a full-scale assembly test and a vehicle shudder evaluation test. The evaluation of the frictional properties of commercial oils using these test methods showed that the static breakaway friction coefficient and the stick-slip properties have generally contradictory performance to each other for automatic transmission. The study of the frictional properties for typical additives and an analysis of the surface of the steel plates with ESCA (Electron Spectroscopy for Chemical Analysis) showed that the frictional properties are significantly affected by the additives adsorbed on the clutch plate sliding surface.
Technical Paper

Application of Dynamic Mode Decomposition to Influence the Driving Stability of Road Vehicles

The recent growth of available computational resources has enabled the automotive industry to utilize unsteady Computational Fluid Dynamics (CFD) for their product development on a regular basis. Over the past years, it has been confirmed that unsteady CFD can accurately simulate the transient flow field around complex geometries. Concerning the aerodynamic properties of road vehicles, the detailed analysis of the transient flow field can help to improve the driving stability. Until now, however, there haven’t been many investigations that successfully identified a specific transient phenomenon from a simulated flow field corresponding to driving stability. This is because the unsteady flow field around a vehicle consists of various time and length scales and is therefore too complex to be analyzed with the same strategies as for steady state results.
Technical Paper

Automobile Navigation System Using Individual Communication Beacon

A communication system that uses roadside beacons to broadcast road and traffic information and private messages to vehicles has been developed. The system, called Road/Automobile Communication System (RACS), was the result of a joint research project involving the Public Works Research Institute and 25 private-sector corporations. This paper contains an outline of RACS and of an onboard system developed by TOYOTA and presents the results of field tests conducted in the Tokyo area. The results not only verify the capability of the RACS system and the effectiveness of the in-vehicle equipment but also indicate the potential of such a beacon based network to improve traffic jam and driving safety whilst providing enhanced communication facilities without increasing radio-wave congestion.
Technical Paper

Color and Height Characteristics of Surrogate Grass for the Evaluation of Vehicle Road Departure Mitigation Systems

In recent years Road Departure Mitigation Systems (RDMS) is introduced to the market for avoiding roadway departure collisions. To support the performance testing of the RDMS, the most commonly seen road edge, grass, is studied in this paper for the development of standard surrogate grass. This paper proposes a method for defining the resembling grass color and height features due to significant variations of grass appearances in different seasons, temperatures and environments. Randomly selected Google Street View images with grass road edges are gathered and analyzed. Image processing techniques are deployed to obtain the grass color distributions. The height of the grass is determined by referencing the gathered images with measured grass heights. The representative colors and heights of grass are derived as the specifications of surrogate grass for the standard evaluation of RDMS.
Technical Paper

Development and Application of Simulation for Low-Frequency Boom Noise and Ride Comfort

This paper investigates a new approach to the quantification technique for road induced vehicle interior noise and vibration within the frequency range up to 40 Hz. By employing the least squares method, both vertical and fore-aft load to each wheel were quantified using transfer function and actual vibration response of the vehicle driven on a road. The coupled structural-acoustic vehicle model using the finite element method, which is also detailed in this paper, is combined with the quantified input load to simulate road induced interior noise and vibration response. Experimental verification, which indicates reasonable accuracy of the simulation, and an application for the prototype development are also presented.
Technical Paper

Development of Assembly Line Verification

To more effectively improve the work on a vehicle assembly line, it is desirable to have a method by which the degree of work load on each person can be evaluated quantitatively; enables us to decide the priority order of improvement; and calculates the improvement effect. We developed a quantitative evaluation method of work load by introducing a concept of physiological stress generated regardless of the type of muscles involved. Applying the burden borne by the body to the load evaluation of various assembly operations involved the problem of complex load measuring methods. We solved this problem by categorizing the load conditions for various assembly operations and converting each to a standard state of loads evaluated by experiments.
Technical Paper

Development of Hybrid System for SUV

Toyota Hybrid System (THS), that combines a gasoline engine and an electric motor was installed in the Prius, which was introduced in 1997 as the world's first mass-produced hybrid passenger car, and was vastly improved in 2003. The new Prius gained a status of highly innovative and practical vehicle. In 2005, combined with a V6 engine, THS had a further evolution as a Hybrid System for SUV, which was installed in the RX400h and Highlander Hybrid to be introduced into the world. This report will explain “new THS” which achieved both V8 engine power performance and compact class fuel economy, while securing the most stringent emission standard, SULEV.
Technical Paper

Development of In-cylinder Mixture and Flame Propagation Distribution Measurement Device with Spark Plug Type Sensor

A new method to measure in-cylinder flame propagation and mixture distribution has been developed. The distribution is derived from analyzing the temporal history of flame spectra of CH* and C2*, which are detected by a spark plug type sensor with multi-optical fibers. The validity of this method was confirmed by verifying that the measurement results corresponded with the results of high speed flame visualization and laser induced fluorescence (LIF) measurement. This method was also applied to analysis of cyclic combustion fluctuation on start-up in a direct injection spark ignition (DISI) engine, and its applicability was confirmed.
Technical Paper

Development of New Concept Iridium Plug

In the field of automotive gasoline engines, new products aiming at greater fuel economy and cleaner exhaust gases are under development with the aim of preventing environmental destruction. Severe ignition environments such as lean combustion, stronger charge motion, and large quantities of EGR require ever greater combustion stability. In an effort to meet these requirements, an iridium plug has been developed that achieves high ignitability and long service life through reduction of its diameter, using a highly wear-resistant iridium alloy as the center electrode.(1)(2) Recently, direct injection engines have attracted attention. In stratified combustion, a feature of the direct injection engine, the introduction of rich air-fuel mixtures in the vicinity of the plug ignition region tends to cause carbon fouling. This necessitates plug carbon fouling resistance.
Technical Paper

Development of Sleeve Clinching Method and Making Practicable

We developed a fastening method to reduce noise levels and fastening work loads. The development was based on research into improved tools and fasteners. This was done in preparation for an increase in elderly worker and female worker population in the Automobile Assembly Shop. The principle of this method is to form female threads inside a straight sleeve by clinching the sleeve around a threaded bolt. We achieved improvements in component material clinching force and a durability for loosening torque compared to conventional bolt and nut methods.
Technical Paper

Development of Torsion Beam Rear Suspension with Toe Control Links

Attaining optimum balance between longitudinal compliance and sideforce compliance steer in a torsion beam suspension system is a challenging task. We developed a suspension in which the longitudinal compliance is almost doubled and the side force compliance steer amount is improved by using the link effect of toe control links. This suspension system has been developed to realize excellent controllability, stability, riding comfort, and road noise performance.
Technical Paper

Development of a Robot Simulation and Off-Line Programming System

In Toyota, a robot off-line programming system was developed five years ago for the use at spot welding processes. And it has been effective to reduce and level off the engineering time. This time we have developed the new robot simulation system. It has three newly features so that the system becomes capable of simulating and programming robots from various manufacturers with different functions. As a result, the new system can be applied to a variety of processes in automobile manufacturing. First, a universal robot programming language was developed which includes a variety of commands such as definitions of motion attributes, signals of inputs/outputs, control of program flow, special functions proper to each process, and so on. And the language can be translated to and from any particular programming language using pre / post processor, so the simulation system needs to deal with only one language.
Technical Paper

Fatigue Life Prediction on Rough Road Using Full Vehicle Co-simulation Model with Suspension Control

A full vehicle multi-body dynamic (MBD) model with suspension control system is developed for fatigue life prediction under rough road condition. The model consists of tires, a trimmed body, heavy attached parts, powertrain, suspension, joints, and a driver model, and includes a suspension control system that varies characteristics of the suspension according to the rough road inputs. For tires, a commercial MBD tire model is employed with identifiable parameters. The models are simulated to run on the optically measured road surface of the proving ground. Apart from the trimmed body, several important heavy attached parts are modeled separately, that represent dynamic behavior that induces complex body input load. These parts, along with suspension and powertrain systems are connected to the body using nonlinear elements such as joints, springs, and dampers. Contact conditions are used to represent mount bushing, hood lock, stopper rubber, etc.
Technical Paper

Finite Element Simulation of Stamping a Laser-Welded Blank

In order to achieve higher assembly accuracy for automotive body, increased body rigidity, and decreased stamping and assembly costs in car body manufacturing, a new method of sheet metal stamping has been developed, in which several blanks of different strength and thickness are integrated using CO2 laser-welding. The stamping formability of the laser-welded blank is limited compared with that of the conventional single blank. It is very difficult to predict the exact decrease in formability for different positions of the weld line and for different matching of materials. Because experimental estimations were indispensable for stamping die designers to evaluate formability at the stage of planning dies, many man-hours were spent conducting actual experiments.
Technical Paper

Future Automotive Technical Trends

This paper provides an overview of the automotive technology and its future trends mainly focussing on Japan. The future automotive technology will basically be on the projection of current technology, although it is expected more progress to be made in advanced and precision control systems. The application of electronics and development of new materials will play a very important role in this area.
Technical Paper

Highly Functional Engine Testing Technology Using an Electric Motor Drive

In contrast to the sensory inspection conventionally performed on the firing bench during final assembly, a technology in which quality inspections are distributed throughout the engine assembly line by using an electric motor to drive the engine, has been developed. Through this process, combustion conditions can be quantitatively tested by component, and leak test conditions can be optimized. Consequently, defects can be detected and their causes identified at an early stage of assembly, thus accelerating the feedback of information to the appropriate process. The result, a level of product quality that is higher than through the conventional means.
Technical Paper

Improvement of Ride Comfort by Continuously Controlled Damper

The object of this study is to investigate the possibility of improving ride comfort, and develop a new damping control system. We supposed and analyzed the ideal damping control for vehicle suspension system using optimal control strategy. The parameter study shows the effect of reducing vehicle acceleration from road excitation. To achieve the same performance with a more simple and lower cost control strategy, we introduce another control strategy called ‘Skyhook model’ proposed by D.Karnopp. Continuously damping control system is developed based on this to avoid some problems that might be caused in the case of a two-stage switching system. Further more, variable control gain depends on vehicle vibration circumstances introduced to realize the adaptation of various road conditions. Using computer simulation and testing the experimental vehicle, effectiveness of this system is evident and the possibility of ride comfort improvement is verified by using this control.
Technical Paper

International Technical Transfer of Automobile Manufacturing

Automobile production technology has been transferred in the order of "automobile assembly technology", "automotive parts manufacturing technology" and "production preparation technology". Transfer of our "automobile assembly technology" has already been nearly 100% completed and, as the manufacture of local parts is promoted and our experiences to undergo model changes are widened, the transfer of "automotive parts manufacturing technology" and "production preparation technology" is making a steady progress. The most critical point that makes the technical transfer difficult is the small automobile markets in developing countries where it is impossible to acquire a sufficient production volume which permits satisfactorily low cost. Various measures to secure a sufficient production volume such as exports and complementation within regions have been taken so far, but any remarkable effect has not been achieved.
Technical Paper

Joint PAJ/JAMA Project - Development of a JASO Gasoline Bench Engine Test for Measuring CCDs

Detergent additives in automotive gasoline fuel are mainly designed to reduce deposit formation on intake valves and fuel injectors, but it has been reported that some additives may contribute to CCD formation. Therefore, a standardized bench engine test method for CCDs needs to be developed in response to industry demands. Cooperative research between the Petroleum Association of Japan (PAJ) and the Japan Automobile Manufacturers Association, Inc. (JAMA), has led to the development of a 2.2L Honda engine dynamometer-based CCD test procedure to evaluate CCDs from fuel additives. Ten automobile manufacturers, nine petroleum companies and the Petroleum Energy Center joined the project, which underwent PAJ-JAMA round robin testing. This paper describes the CCD test development activities, which include the selection of an engine and the determination of the optimum test conditions and other test criteria.
Technical Paper

Overview and Future Plan of Automotive Electronic Systems

This paper provides an overview of automotive electronic systems put into products over the past decade, and describes automotive electronics which have been demonstrated in experimental cars. In addition, future electronic systems found to be promising for the practical use in coming years and the direction of development of electronics are also discussed, as an extention of the overview mentioned above.