Honda has developed the ultimate clean power fuel cell vehicle, the FCX, to respond to environmental and energy issues. Honda simultaneously marketed the FCX in the U.S. and Japan in December 2002. This vehicle is provided with a compressed pure hydrogen type fuel cell and an Ultra capacitor as a combined power source, and is driven by a high-performance drive motor. Honda’s original packaging technologies enable these units to be fitted in a compact body. The FCX has a practical driving range, high maximum speed, and excellent power performance. The vehicle also ensures crash safety from all directions and comfortably seat four adults.

To respond to increasing environmental concerns and demands for clean energy, Honda has developed an emission-free clean power train employing fuel cells. This power train has been fitted in the FCX fuel cell vehicle, which is being simultaneously marketed in Japan and the US in a world first. The new power train is made up of a combined pure hydrogen fuel cell stack and Ultra capacitor system, and a reluctance torque traction motor. In addition to having a zero level of emissions of CO₂ and other pollutants, the new power train has raised the energy efficiency of the FCX to 45%, almost 1.5 times that of an electric-gasoline hybrid vehicle (HEV) of equivalent size. The FCX also has higher fuel economy than an HEV, and superior acceleration from a standstill to a gasoline internal combustion engine vehicle (ICEV).

A practical fuel economy measurement method has been developed for fuel cell vehicles. The weight method was selected for study from among the various fuel economy measurement methods available for pure hydrogen-type fuel cell vehicles as a direct measurement method which was accurate and could be produced at a comparatively low cost. Solutions were provided to the drawbacks of measurement errors caused by pressure variations in the fuel pipes and lowered hydrogen purity due to air entering the pipes. This development project assisted in fuel economy measurements for the Honda FCX, the world’s first market-ready fuel cell vehicle; it also provided measurement system for the Environmental Protection Agency (EPA) tests of the same vehicle, which resulted in the world’s first confirmatory test of a fuel cell vehicle.

A compressed gas system previously utilized in natural gas vehicles (NGV) was utilized in the Honda FCX. Rapid filling tests of the high-pressure hydrogen tanks of both Type 3 (Aluminum liner) and Type 4 (High Density Polyethylene) were carried out using compressed hydrogen gas. Type 3 tanks showed better performance. This result can be explained in terms of the difference in heat diffusion coefficient between aluminum and HDPE. The shortest filling time from 1MPa to 34.4MPa to enable a gas temperature increase (ΔT) of 45°C to be observed using Type 3 tanks with a total volume of 156.6 dm³ was found to be 3.6 min., almost the same as the refueling time of present gasoline vehicles.

An electric double-layer capacitor system has been developed for the Honda FCX fuel cell vehicle. This high-power capacitor system offers more than 30% higher output power and more than twice the power density of the nickel-metal hydride batteries used in hybrid electric vehicles (HEV) at an equivalent system voltage, and satisfies automotive power requirements. The new system is equipped with a capacitor cell protection system which monitors capacitor voltage and provides equalization and fail detection functions, and heat insulation and a cooling system control temperature increase both when the vehicle is parked and when it is running. The effectiveness of these systems has enabled the new capacitor to satisfy durability and reliability requirements in unit tests and running tests.

An electric double-layer capacitor has been developed as an energy storage device for a fuel cell vehicle. This capacitor has been utilized in the Honda FCX fuel cell vehicle marketed in December 2002. The capacitor features a rolled electrode housed in a cylindrical case. The aluminum foil at the sides of the electrodes is welded to collector plates with radial U-shaped grooves; the structure is welded together after alignment of the terminals at the center of the collector plates with the holes in the center of the case and case cover. This configuration has enabled the achievement of a charging rate of 86% in the electrode and a connection resistance of less than 0.05mΩ. Due to this packaging the unit displays the world’s highest level of performance for a capacitor cell, with a specific power density of more than 1 500W/kg and a specific energy density of 3.9Wh/kg. Tests show that the longevity of the capacitor is equivalent to or greater than that of the vehicle in which it is fitted.

An electrode has been developed for the electric double-layer capacitor utilized in the Honda FCX fuel cell vehicle. Control of the property of the pores of the activated carbon which is the main material and efforts to increase electrode density have enabled the achievement of a capacitance per unit volume of 17.6F/ cm³, while optimization of the electric conductive adhesive has brought surface resistivity to 6.7Ω·cm². Excellent durability has been achieved by controlling residual organic impurities in the production process. As a result, the capacitor cell in which the electrode is utilized has a capacitance of 1 350F and an internal resistance of 2.5mΩ, is highly durable, and was judged suitable for use in the Honda FCX.

Electric double-layer capacitor covers are required to seal in organic liquid electrolytes, isolate positive and negative electrodes, and maintain pressure tightness. An insert mould process using chemically combined aluminum and resin and a rib to prevent resin shrinkage have been developed to enable these requirements to be met. In this process aluminum and resin are bonded by insert moulding after triazinedithiol electrocoating of the aluminum surface. Optimization of the formation of the triazinedithiol coat and insert mould conditions and the establishment of a rib between the aluminum and resin have enabled the production of covers which satisfy the requirements enumerated above after acceleration tests based on actual use conditions. The long-term sealing performance of the new covers has also been verified.

Micro-cogeneration units (MCHP1.0) for residential use have been developed. These units produce both hot water and electricity. This process is carried out in an extremely efficient manner. By fueling the system with clean burning natural gas, carbon-dioxide emissions can be further reduced. Power line from those units can be connected to the electricity grid. Honda MCHP1.0 has reached 85% (LHV) of total energy efficiency, 380mm width of enclosure and 46dB(A)/1m of operating noise level by advanced small engine technology and inverter generator technology accumulated in Honda power equipment business. These units are the smallest ones as commercialized cogeneration units.

“RINCON TRX650FA” of a new concept, which can ride enjoyably and comfortably for the recreation use mainly, was developed as Honda’s flagship model of utility oriented ATV(All Terrain Vehicle) series. An electronic controlled three speed automatic transmission with torque converter was employed for the first time in the world and a powerful and comfortable running performance was realized by combining with newly developed 648cm³ single-cylinder engine of flat torque type. Moreover, riding comfort and the running stability were achieved in the higher performance by adopting a rear independent suspension for the first time for Honda and a radial tire. Some weight reduction technologies such as an aluminum alloy forged suspension arm was effective for the higher maneuverability during running on the rough road. As a result, these advanced technologies by an original new design of SUV concept realized the powerful running performance.

The world’s first engine with a torque converter has been developed for the paramount TRX650FA in Honda’s utility oriented ATVs (All Terrain Vehicle). A linear solenoid valve and a hydraulic clutch control the creep phenomenon at an idling peculiar to the torque converter. The start-ability is equal to a wet automatic centrifugal clutch for conventional ATVs. A pleasant running like automobiles was realized by employing electronically controlled three-speed automatic transmission. To assemble the transmission and the engine using an existing production line was enabled because the lubrication systems of both the transmission and the engine were designed in common. A substantial mass reduction was achieved by the optimizing design of each part.

Concerns about environmental protection and energy saving are growing in the world, and Thailand market also strongly requires an improvement of fuel consumption and emission for motorcycles. Therefore, we developed a 125 cm³ 4-stroke engine with revolutionized fuel consumption and emission for Thailand market. For enhancing the fuel consumption, the friction of contact surfaces of rocker-arm and piston and the mechanical input of generator was reduced. Also the combustion efficiency was enhanced by changing the ignition timing by throttle opening. For reducing the emission, the secondary air pulse induction system, introducing fresh air into an exhaust port, was employed. As a result, the fuel consumption was enhanced 30% in ECE40 mode compared to the 108cm³ engine of previous model. The emission was reduced 55% in CO and 60% in HC+NOx against the value of the 4th emission regulation in Thailand.

Recently, concerns about environmental conservation have been growing, and reducing the exhaust emission and enhancing the fuel economy are being major subjects for small motorcycles. Therefore, electronic control fuel injection systems, which can finely control an air-fuel ratio, have been employing. This time, the ECU integrated throttle body system for the electronic control fuel injection system, which is compact and low-cost, for a small displacement engine was developed. Features of this system are to combine two modules. The modules are throttle body module with several bore sizes in series and ECU module with electronic control unit, sensors, and idling-air-control device. As a result, the complex wiring and piping were minimized, the miniaturization was achieved, and the system with generality that enables to install to the single cylinder engine from 50cm³ to 250cm³ was achieved.

Engine mount development for the manual transmission 2003 3.2 CL Type-S included the use of engine rock dampers, a new technology for Honda. A damper mounted between the engine and subframe with isolation rubber to control engine-roll motion was developed as a countermeasure to improve shock hunt. Engine rock dampers are found to be an effective means of controlling engine roll stiffness for transient torque input. Shock hunt targets are achieved, sports coupe drivability is maintained, and marketable noise and vibration levels are preserved.

An image-based gesture recognition module has been developed as a part of biped walking humanoid robot ASIMO’s man-machine interaction function in order to enhance its autonomy. ASIMO recognizes human gestures based on statistical analysis, using spatiotemporal variance of three-dimensional(3D) positions of the face and hand. It is able to distinguish 10 kinds of gestures and postures on left and right side each. It is also able to recognize a position pointed by an operator from the relative position of operator’s head and hand and from the direction of the arm. This is calculated by PCA(Principal Component Analysis) on a 3D-point set observed in the proximity of his arm. These components are implemented in a layered structure to reduce complexity, and in optimally designed communication structure to minimize processing resources. This effort has resulted in a comprehensive image processing system in ASIMO’s onboard computer.

An intake port design support tool using a CFD(Computational Fluid Dynamics) software based around the PCC (Partial Cells in Cartesian coordinate) computational mesh method was applied during the development of a motorcycle engine. The CFD analyses were performed with a relatively quick turn around time due to the reduced mesh generation time. To ensure the practical use of the tool, the CFD results have been validated using measurement data. Also recommendations for the mesh setup are described as well as details of the post processing improvements which have been implemented. This has confirmed the CFD software as a suitable design support tool.

Three-dimensional (3D) CAD systems have been used for design and development of automobile transmissions for several years. These systems have been improved to the point that they can be used to design sand castings which have precision equivalent to that mass-produced from die molds. Since automatic meshers for CAE analysis have improved so much, it has become increasingly common practice for designers to use, as is, the 3D models of prototype parts and mass products in CAE analyses to make decisions on the detailed specifications of components. The next step in this revision of CAE systems is to re-create them as a more designer-friendly environment, and allow designers to use these systems to perform CAE analyses not only of individual components, but also of assemblies, a much more difficult task.

The characteristics required for wheel function were clarified and a thin, lightweight aluminum wheel was developed. The method adopted to reduce wheel thickness involved improving the mechanical properties of the materials by modification of the die layout. In the newly developed die layout, the gates that are set at the periphery of the outer rim are positioned at the bottom of the slide die so that the number of gates, their locations, and their shapes can be changed freely as needed. This arrangement made it possible to reduce the thickness of the material and increase the cooling rate. The faster cooling rate resulted in a finer structure, yielding greater elongation, which improved the fatigue strength and increased the toughness of the material. As a result, the thickness of the product in the inner rim and spoke portions was reduced 25%, achieving a 10% reduction in the weight of the wheel. This also shortened the casting cycle time and eliminated the need for a reforming press, therefore improving productivity.

To rationalize the layout and increase the mass productivity of HEV drive motors, integrated molding of high voltage distribution parts using plastic insulation material was investigated as a method to reduce the number of parts and increase ease of assembly. The enlargement of part dimensions occurring with the change to molding plastic from using the former cure coat-type fluoropolymer insulator material was minimized and waterproofing performance was increased. Selection of materials on the basis of measurements of heat strain in plastic molded parts and full molding using floating over molding ensure waterproofing. Study of the design basis for high-voltage insulation clarified the minimum insulation distance, enabling the development of an integrated bus ring molding technology which allows mass production without increasing the dimensions of the parts.

A positive proportional relation between arc length and arc illumination was found to apply in arc welding. By applying this relation, a control technology was developed that maintains arc length at a constant fixed value during welding. This enabled control that is able to maintain a fixed arc length of 1.0 mm or less, which was not possible with conventional arc voltage control. As a result, stable, uniform melting was achieved on ultrathin boards 0.5 mm thick or less by the application of low-current, low-voltage welding.

The auto-ignition is focused as a combustion process, where improving efficiency and lowering NOx emission could be compatible. A current subject would be controlling combustion process. Honda demonstrated a method to control the auto-ignition, i.e. Activated Radical (AR) Combustion, in several commercial motorcycle engines.

Through the experimental analyses of the AR Combustion, this article shows that control of the gas exchange generates a temperature for the auto-ignition in the end of compression stroke, due to heat exchange between residual and new mixture. It is also revealed that its combustion speed is affected by the engine speed, scavenging efficiency and etc, however, 10% to 90% mass burn timing is settled on the same crank-angle duration, as result, regardlessly of the engine operating conditions. This is owing to the dualism of the residual gas, i.e. combustion promotion action as heat energy potential and the inhibitory action as the inert gas. Both action should balance for the two-stroke gas exchanging method for controlling auto-Ignition.

Development of the 1kW-class inverter unit with a small engine generator that conforms to “Guideline of the interconnection technology requirements” has succeeded. To connect distributed sources such as wind power generation , photovoltaic generation , or cogeneration to the utility grid, it is necessary to detect demand-side problems including the distributed sources (short circuit, ground fault, troubles in generated voltage or frequency) and to detect problems in the grid (power failure and troubles of voltage or frequency). It is also necessary to protect both electric power systems and distributed sources and electrical appliances. The inverter unit uses two types of islanding detection method that is passive one and active one. Total distortion factor is reduced to less than 1% by applying two kinds of input current to the power supply unit. Efficiency of the interconnection inverter unit has been achieved 91% and total efficiency of power generation of the cogeneration unit has been achieved 20%.

The mechanism of generation of noise was analyzed and research on noise reduction was conducted in pinion shift-type starters for idle stop systems. Both pinion shift noise and cranking noise are components of the noise generated during engine start; vehicle tests demonstrated that cranking noise is produced for a longer period and causes greater discomfort to driver and passengers, and countermeasures were therefore devised against this form of noise. Bench tests revealed that gear whine was a more significant factor in cranking noise than gear rattle, and countermeasures therefore targeted this source of noise. The spur gears conventionally used in pinion shifttype starters were replaced by helical gears and the contact ratio was increased, reducing noise by 7dB. When establishing gear specifications, analyses of stress in the sections making contact were conducted to enable judgment of the ease with which damage occurs to gear end faces during pinion gear shifting. The relation between angle and stroke of the pinion gears during shifting was optimized to achieve superior shift performance.

In computer simulation method for motorcycle rider motion in collision of motorcycle to car, we have validated the computer simulation results in two cases in which a motorcycle runs into a running car side with 45 degree and 90 degree angles. The simulation software of explicit finite element method (FEM) has been used, because of its capability for expressing accurate shape and deformation. The mesh size was determined by considering a simulation accuracy and a calculation time, and FEM model of a motorcycle, an air bag, a dummy, a helmet and a passenger car were built. To shorten calculation times, a rigid body was adopted to a part of the model and contact regions were limited. As the results, higher accuracy of head speed and posture at the ground contact of dummy was obtained in simulations of the two cases this time. Calculation time of the two cases was about 50 hours with the computer of 14.4Gflops.

The paper presents new Object Oriented Formulation of the FE algorithm that encompasses traditional FE, Super Element, experimental data and rigid body mechanics in a single calculation environment. The new formulation is implemented in a software for dynamic crash simulation of an arbitrary 3D frame structure discretized into Super Elements and subjected to large dynamic crash loading. The paper presents basics of the general algorithm and element formulation. The theoretical part is followed by the discussion of benchmark tests and result of application of the real world structures.

Micro-slip motion occurs in the metal contact surfaces around the hub bearings of the driven wheels when automotive driving torque is applied. A stick-slip noise can accompany this slip motion. Analysis of the occurrence of stick-slip has shown that it is caused by a combination of factors. The research described in this paper has discovered previously unknown causes. Excess insertion load or axial force causes non-uniform strain in the bearing inner race; this strain builds up even after the load is released. Changes occur in the lubrication conditions of the press-fit face of the hub and the bearing inner race with varying insertion speed and humidity conditions, leading to the generation of excess insertion load. An effective method for prevention of stick-slip is proposed on the basis of this analysis.

This paper describes a method for prediction of automotive sound package acoustical characteristics. This method is based on the transfer matrix approach and is applied to calculate the TL and absorption of multilayered insulation components from the acoustical impedance of each layer. The predicted results are necessary as fundamental input parameters of SEA vehicle models. The accuracy of this method was verified by comparing the predicted TL and absorption values of trimmed components with measurement results.

A CAE technology which can be applied from the concept stage of BIW in the design of lightweight, highperformance vehicle bodies was developed. This technology formulates an FE model from design lines and frame cross-sections, and enables analysis of body performance using the frame performance indicators static characteristics, dynamic characteristics and side collision characteristics. Because this technology does not require CAD diagrams, designers can quickly employ numerous ideas and images in FE models and utilize CAE to predict performance, enabling the creation of new frame structures. Comparison of analysis results with conventional high-accuracy large-scale models has confirmed correlativity between the methods, and verified that it is possible to predict performance from the concept stage of BIW using the new technology. This paper discusses the application of CAE at the concept stage of BIW to examine frame structure and predict performance when altering the design of a vehicle.

Taking the elastic deformation of parts into account in calculations to simulate the characteristics of suspension alignment was confirmed to improve prediction accuracy. Taking the elastic deformation of the main elements of the overall suspension, the subframe, and the body into account made it possible to accurately determine the side force compliance at the tire contact point with the ground, and also to clarify the contribution made by each of those parts. Development of an elastic body modeling method that accounts for significant deformation made it possible to improve the accuracy of alignment prediction, even in parts such as the twist beam axle that undergo significant deformation. Software was developed to assist with design analysis so that these prediction methods could be utilized in practical design work.

A coupled simulation using concurrent execution of mechanical and control simulations was developed and applied to prediction of vehicle behavior while under mechanical control. Also, a technique for automatic generation of real-time programs based on mechanical models applicable to HIL simulators, which require realtime executable calculations, was developed. This greatly eased accounting for the influence of vehicle body mechanisms in the behavior of suspensions and other systems. Thus, it is now possible to carry out ‘paper experimental tries’ and HIL simulator tries of simulations of full vehicle behavior under control by systems such as EPS or VSA. Formerly difficult predictions of vehicle behavior due to steering wheel torque or in non-linear regions have become possible.

A carbon fiber-reinforced plastic (CFRP) hood and rear spoiler were developed to achieve weight reduction in vehicle body parts. In addition to its low weight, CFRP has the high degree of freedom which is the molding characteristic of polymer materials. It has therefore been possible to integrate undercut areas with sections in which plate thickness varies to achieve the required functional characteristics with no increase in weight. Utilizing CFRP instead of aluminum for the hood has enabled integral molding of aerodynamic air ducts, and bonding of the skin and frame with adhesive joints has increased the section modulus of the entire hood, making it approximately 30% lighter. Forming the rear spoiler from CFRP rather than sheet molding compounds (SMC) has enabled the undercut section, composed of numerous curved surfaces, to be monolithic constructional molding without the necessity of joining separate parts. Thus, a reduction in weight of approximately 40% against the ’93 model has been achieved, despite the increase in size.

In an effort to reduce cost and foster an all-olefin material direction, a polypropylene material has been developed to perform without paint in applications traditionally requiring paint. An existing instrument panel polypropylene’s scratch resistance has been enhanced by talc encapsulation, increased surface lubricity and reduced talc particle size. The additive loadings and types were balanced with physical property performance and material cost. Mold flow analysis and a sequential valve gate molding process were used to optimize the part appearance. The result is an impactmodified polypropylene with scratch characteristics equivalent to painted polypropylene with a minimal cost increase.

A new electrocoating has been developed as part of the ongoing efforts to move towards the use of lead-free cationic electrocoatings as auto body primers. The new e-coat dispels concerns such as increased cost and inferior rust protection due to the absence of lead, and will be able to be easily introduced to automotive production lines. Several technologies were necessary for this development: new corrosion inhibitors, essential for rust protection; improvement of the perfomance of the base resin of the paint film; methods to control the viscosity of the deposited film in order to prevent deterioration of the workability and the appearance of the paint; and optimization of pigment mixture to control costs.

To expand the scope of parts in which recycled bumper materials can be used, methods were developed to modify the properties of the materials to enable adaptation to the requirements demanded in the individual parts. The parts targeted in the research were 1) Aerial under cover; 2) Side spacer; 3) Evaporator case; 4) Rear shelf; and 5) Floor carpet. The following methods were used to modify the properties of the material for the respective parts: 1) Fluidity was improved through addition of constituents with low molecular weight; 2) Flexural strength was improved by addition of constituents to chemically bond filler and matrix resin; 3) Shrinkage performance was improved and flexural modulus was increased by addition of filler and resin with high flexural modulus; 4) Flexural modulus was increased by addition of filler; 5) Tensile elongation was improved by addition of an elastomer compatibilizer. In each case, these methods enabled the use of recycled materials at an equivalent cost to virgin materials.