Honda Date of issue: Apr 01, 2001
Development of the Humanoid Robot ASIMO
Honda has been conducting research on biped walking humanoid robots as a challenge toward a new field of mobility.This paper discusses ASIMO, the Advanced Step in Innovative MObility developed as a result of our efforts in this field. Our target in this development was a robot that could co-exist with humans and that could actually be useful to humans. This target was achieved through the development of a minimally sized robot (height: 1200 mm, weight: 43 kg) that could conform to a real living environment. Also, by further fostering past research we were able to advance the functionality of the robot. In particular, by adding “free walking technology,” which includes predictive control technology, to the existing walking stability control, we were able to achieve a biped robot that can move more smoothly and continuously.
By Masato HIROSE、Toru TAKENAKA
Styling Design of the Humanoid Robot ASIMO
The Honda humanoid robot ASIMO was developed as a challenge to create robots with a higher level of mobility than has existed before. For the first, the automotive styling division took part in this project from the initial planning stages. Furthermore, this humanoid robot is a product in a brand new category that does not have an established market. We proceeded in our development with our own unique proposals while at the same time we listened to the opinions of people, both inside and outside Honda, in order to determine our styling direction. Also, as ASIMO is a humanoid robot comprised of a multitude of moving elements, we made maximum use of computer technology from the initial stages of development. We were able to simulate, for example, walking motions with computer graphics to achieve an overall balance between styling and structure. By adding automotive styling experience to the robotic development cultivated to date, and by including new styling methods, we achieved a unique sense of value as well as familiarity and friendliness with the ASIMO styling.
By Akio KOIKE、Takeshi KOSHIISHI
Development of the 2001 Year Model Civic
In developing the new model Civic, high performance targets were set for comfort, efficiency, and style based on the overall concept of a “comfortable life,” as well as for collision safety, driving stability, and noise and vibration. The engine and chassis have a compact design to ensure a wide cabin space relative to the vehicle’s outer dimensions, and a flat floor was achieved with a centralized under-floor layout for the exhaust and fuel systems, thus achieving a “comfortable space.” In addition excellent fuel economy of 19.4 km/L in the 10-15 mode was achieved, and the Civic also obtained J-LEV certification. Further, the high performance targets were achieved in the areas of driving stability, noise and vibration performance, and collision safety performance.
By Chitoshi YOKOTA、Fumio KUBO、Tsuyoshi OHKUBO、Yoshinori NAKAMURA、Tadashi WATANABE、Shigeru YADA、Kouichi FUNATSU
Development of the New Civic Suspension
New front and rear suspensions have been developed for the new Civic to achieve a highly efficient package layout and good vehicle dynamic performance. The reduced front overhang of 60mm, collision safety target and linear front suspension toe curve are achieved by adopting a strut suspension with a steering gearbox that is mounted 250mm higher than the usual strut suspension. The increased rear luggage room width of 142mm and linear rear suspension toe curve are achieved by adopting an in-wheel double wishbone suspension with a lowered rear damper position. By having these suspension characteristics, the new Civic has enhanced handling and riding comfort performance over the previous Civic.
By Toshiya HASEGAWA、Noriaki Wada
Automation of Mode Driving Operation for Exhaust Gas Measurement
Mode driving is being automated using automatic driving units (robots) with the aim of reducing the number of man-hours needed for the measurement of automobile exhaust gases. Automation using robots offers significant advantages, particularly in high-altitude exhaust gas emissions tests, as it liberates workers from harsh working environments.
This system makes it possible to fully automate all work procedures by constructing automatic cooling fan start/stop systems and automatic hood opening/closing systems, which were issues for full automation with robotic driving under high-altitude conditions. In addition, vehicle speed trace accuracy relative to changes in atmospheric pressure inside the test chamber equivalent to that for driving with a human driver was realized by using separate acceleration parameters for low- and high-altitude conditions and optimizing the control parameters. These changes made it possible to reduce the number of staff and time required for tests and to eliminate tasks in harsh working environments.
By Yoshiharu ABE、Yoshihiko KOBAYASHI
Study on the Generation Mechanism of Backfires
In motorcycle engines, backfires can become an issue with increased cylinder bore size. It has been thought that backfires are caused by an extra ignition at an overlapping top dead center or by backflows into combustion chamber of high temperature exhaust gas during exhaust stroke. As a result of taking pressure measurements inside the combustion chamber, at the inlet and exhaust ports, and of observing the inside of the combustion chamber with a high speed CCD camera, it was found that an extremely slow-burning cycle exists which continuously burns during the exhaust stroke. Further, it was confirmed that the extremely slow-burning cycle caused the fresh air-fuel mixture introduced in the subsequent intake stroke to ignite thus generating backfires. This paper provides an overview of the investigation and describes some of the factors that influence the extremely slow burning cycle.
By Masaya ADACHI、Shinji SAITO
Development of an On-Board System for the Simultaneous Analysis of Tailpipe Exhaust and Ambient Air
An on-board sampling and analysis system has been developed, capable of measuring on-road emissions at extremely low levels. Ambient air quality can also be monitored and compared to tailpipe emission levels in real time during actual roadway driving. This FTIR-based system can measure several chemical species, including HC, NOx, and CO. Hardware and software were developed to facilitate the monitoring of target species at concentration levels below 1ppm, in the harsh environment of an on-road vehicle. Countermeasures were required to mitigate or eliminate the effects of chemical interferences and vehicle motion. Algorithms were developed to calculate results on a mass basis (g/mi), thereby allowing such data to be acquired in real-world conditions outside a laboratory environment. This system has been used in the development of near-zero-emission vehicle technology; it has allowed instant assessment of vehicle software tuning during actual roadway driving. It is currently being used to determine the true impact of various advanced-technology vehicle classes upon the environment. In this capacity the system is performing a dual role as an on-board analyzer and also as a high-sensitivity ambient air monitoring station.
By Jeff JETTER、Norio SUZUKI、Seiji HATCHO、Shinji MAESHIRO
Computer-aided Engineering Technique for the Reduction of Exhaust System Noise and Back Pressure
A technique has been established for predicting the effects of changing cold end parts in an exhaust system on engine output and exhaust discharge noise. This technique enables the sharing of such parameters as velocity and pressure due to the application of flow analysis and acoustic analysis. One-dimensional compressible fluid analysis was used to predict engine output, and a value derived by steady flow analysis using the three-dimensional finite volume method (FVM) was introduced for the effective flow area, which is one of the parameters. Further, it was clarified that exhaust discharge noise is determined by the sum of pulsating noise and flow generated noise. The pulsating noise was predicted by the application of acoustic analysis using the three-dimensional finite element method (FEM). For the FEM input boundary conditions, precision verification was carried out using both pressure fluctuation values derived by compressible fluid analysis and measured values from an actual vehicle, while velocity derivable by steady flow analysis was introduced as a parameter for flow-generated noise prediction. As a result, it was possible to predict the variations of engine output caused by changes in the exhaust system with an accuracy of ±2%, and to predict exhaust discharge noise within ±2 dB. This has made it possible to optimize muffler design by implementing three-dimensional computer-aided design (CAD) modeling to evaluate parts performance from the initial layout investigation stages.
By Hidekazu AKIYAMA、Tsuyoshi ISHII、Satoshi WATANABE
Air Quality and Emission Control Strategy Evaluation Software BRIDGE PROGRAM
An original software tool, BRIDGE PROGRAM, has been developed to simplify the evaluation of emission control strategies for improving air quality. It is particularly effective for in-house evaluation of emission inventory reductions and air quality impacts as a result of introducing innovative, low emission technologies. The software uses a Relational Database Management System (RDBMS) to manage and modify the large emission data sets that characterize specific regions. Mobile, stationary, and biogenic emission rates can be scaled up or down, individually or by groups of source categories. The software automatically generates compatible files of gridded emissions for photochemical models used by regulatory agencies. This software has been used to modify emission inventories in regions of the United States and Japan. This paper describes the methodology and utility of the new software.
By David DEWITT、Yoshiaki MATSUZONO
Development of an Ultra Flat Torque Converter by Applying Three-dimensional Computational Fluid Dynamics
A method has been created to optimize design parameters using three-dimensional CFD to analyze the internal flow condition of a flat torque converter, and one-dimensional angular momentum theory. This method has been used to design a torus and blade configuration which reduces flow loss, and to optimize the specifications of the stator, which has a great affect on torque capacity characteristics. This has allowed the development of the thinnest ultra flat mass production torque converter in the world without sacrificing torque converter performance.
BY Hiroya ABE、Tetsuro MARUYAMA、Masatoshi SAKATOU
Application of Helical Gear Tooth-root Bending Stress Simulation for Automotive Transmissions
This technique was adapted from Professor Aizoh Kubo’s program, which is capable of simulating tooth-root bending stress in helical gears, while taking into account the effects of misalignment and tooth surface configuration. A technique was created that is capable of more accurately simulating in a short time helical gear tooth-root bending stress in an actual automotive transmission during the first stages of design. The resulting tool was named GRANPLI. Misalignment in actual transmissions was measured using original gap sensors for a drive gear and driven gear behavior at low revolution speeds, and a misalignment map was created with respect to the loads. Particular attention was paid to the position of the primary reduction gear with respect to shaft orientation, the phase angle of the final reduction gear and the differential case, and so on. The appropriateness of calculation results obtained by GRANPLI was confirmed through comparison with data from measurements by strain gauges attached to a gear in an actual automotive transmission.
By Chiaki UZUKI、Yoshikazu TATENO、Kohki MIZUNO、Masayuki NAKADA、Masami HIRAOKA
Enhancements in Vehicle Stability and Steerability with Slip Control
To enhance both vehicle stability and steerability, vehicle dynamic parameters such as vehicle side slip angle, road friction coefficient, and tire side forces were precisely estimated in real time; and, utilizing four wheel slip control, a logic for optimizing vehicle dynamics was formulated. Tests on ICE-and snow-covered roads demonstrated the effectiveness of the control, and confirmed the validity of the logic.
By Keiyu KIN、Hiroyuki URABE、Osamu YANO
Study of the Dynamic Characteristics of the Suspension as Related to Brake Judder Reduction
The reduction of brake judder requires refined tuning of the dynamic characteristics in the suspension, which as an oscillatory system has a great influence on brake judder. Here, a component model of the suspension is used to calculate its vibration mode and frequency characteristics. This makes it possible to conduct a comparative examination of the influence of the suspension geometry (the main factor in brake judder), bushing characteristics, parts weight, and other such factors by means of simulation. As a result, the values predicted by calculation have been found to correspond closely with the actual measurements, and compliance steer has been confirmed to play a significant role in reducing brake judder.
By Tetsuya YAMAGUCHI、Kiyoshi KOBAYASHI
Enhancement of Cup Seal Performance in Brake Wheel Cylinders by Hyper Elastic Analysis
The shape of the cup seal that is installed in the wheel cylinder of drum brakes was examined using FEA hyper elastic analysis. The cup seal material was changed from the often used SBR to EPDM resulting in enhanced heat and wear resistance. Next, a prototype cup seal was made in a determined shape based on the results of the investigations. Various durability tests were carried out with the results confirming both enhanced durability and appropriate sliding resistance.
By Takeshi ITO、Kiyoshi KOBAYASHI、Koichi NAKAMURA
Research of Control Countermeasures for 3D Uneven Solar Radiation with Automatic Air Conditioning Systems for Automobiles
A new automobile air conditioning system was developed that is capable of maintaining passenger comfort under changing and uneven solar radiation conditions. This project differentiated the solar radiation energy that is absorbed by the human body affecting passengers directly, and energy that is absorbed by the car body and radiated to the passengers by means of the cabin air. Values for these two were then derived for every position of the sun. Based on the results, a map was created that enables the air conditioning system to change the coefficient adjusting for the influence of solar radiation. A control system has been developed that calculates the position of the sun relative to the automobile by means of a Global Positioning System, and provides only as much cooling as is needed to offset the amount of solar radiation energy absorbed by the passengers according to the position of the sun. An automobile with this air conditioning system installed was subjected to field study tests, which confirmed that passengers felt a constant level of comfort even when the direction of the sunlight changed with respect to the car body.
By Isao TSUNODA、Ikuo TAKAMATSU、Hironori SHUTO
Application of Finite Element Analysis Using 3D Auto-mesher for Transmission Development
In order to effectively utilize three-dimensional models, the quality of a 3D auto meshing function linked with a 3D CAD system and 3D models was improved. This was achieved with the aim of performing finite element analysis on, without modification of, detail models including detailed fillets, draft angles and other complex shapes which can be applied to die manufacturing. As a result, 3D detail models with a data volume in excess of 100 MB could be converted to CAE models by auto meshing, allowing designers to perform finite element analysis at the transmission design site.
By Shigeru NAGAI、Takanao UCHIDA
Development of Metal Pushing V-Belt Stress Simulation for Continuously Variable Transmission
This paper describes the development of a new method to evaluate dynamic behavior and stress for durability simulations of metal pushing CVT V-belts undergoing high rotational speeds. The explicit finite element method typically used in crash analysis is adopted to simulate the high rotational speed range. A finite element model of the complete metal pushing V-belt including the layered bands is constructed where the torque is transmitted by the friction of the contact surface. In the simulation, the rotational speed gradually increases from zero to the target speed. As a result, it is possible to predict the belt stress in the high speed range and as this stress correlated with the test results, belt durability can, for the first time, be judged. To make this simulation more accessible to designers, customized pre-and post-analyzing tools were developed that enable the quick creation of new belt models.
By Takemasa OKANO、Toshihiro SAITO
Development of a New Software for Objective Evaluation of Interior Sound of Sports Cars
An evaluation method was developed for the interior sound of sports cars. This method was derived from the precise subjective evaluations of 12 sports cars and consists of objective parameters. Further, it was found that there is only a slight difference in perception of sporty sound between Austrians and Japanese. As a result of this research, software for use in development of sound quality was developed and will be useful in the development of sports cars with optimum interior sound.
By Franz K. BRANDL、Siegmund THOMANN、Werner BIERMAYER、Tsuyoshi YAMASHITA、Yasuo ISHII
A Method for Measuring the Excitation Forces Inside Engines
This paper presents a method for directly measuring the excitation forces exerted on the main bearing journal from the crankshaft. A method was developed for obtaining the amplitude and direction of the constantly changing excitation forces, which had not previously been accomplished. The excitation force direction and absolute value are obtained when the relative error between the strain during actual operation obtained from multiple strain gauges affixed to the inner surface of the main bearing journal and the strain estimated from calibration curves is at a minimum.
By Naoki KAMIMURA、Yukitaka TAKAHASHI、Toshifumi SUZUKI
Prediction Technique for Gear Noise Transfer in Engine Mounting Systems
Prediction methods using finite element method (FEM) analysis were investigated to construct technology for predicting the aggravation of gear noise and other high frequency vibrations due to engine mount transfer in the initial development stages. Engine mounts are normally comprised of rubber clasped between metal brackets on the power plant and chassis sides. Coupled vibration including these metal parts is a problem for high frequency vibration transfer. This study showed the mount vibration transfer characteristics are a composite of the response characteristics of each metal part, and that simple evaluation by the response level can be used to predict the aggravation of noise in the cabin. In addition, modeling the chassis frame and case to which the metal fittings are joined, and modeling the clamping rigidity of the joints using spring elements, made it possible to accurately calculate the frequency response (error of resonance frequency: approximately 5%).
By Akiko SEKINE、Masayuki RYOUKATA、Kazuomi KIKU
Development of a Night Vision System (Vehicle-Pedestrian Collision Avoidance System)
A night vision system has been developed to help reduce vehicle-pedestrian accidents occurring at night. High temperature objects presumed to be pedestrians are detected by processing the images from infrared stereo cameras mounted on the front of the vehicle, and the possibility of a collision is judged by calculating the position and relative moving vector of the pedestrian. In addition, voice guidance is provided and a highlighted infrared image of the pedestrian is displayed at the bottom of the front windshield using a head-up display (HUD) installed in the instrument panel.
As a result of confirming detection performance on a test course, it was found that the possibility of collisions with pedestrians on the road and crossing the road could be judged.
Further, as a result of confirming evasive action on the part of the driver with respect to the provided information, this system was found to be a useful means of reducing vehicle collisions with pedestrians. Further development is needed to bring this kind of system to the point of practical application.
By Nobuharu NAGAOKA、Takayuki TSUJI、Masahito WATANABE、Hiroshi HATTORI
Rear-end Collision Velocity Reduction System
Through the use of traffic accident statistics and questionnaire surveys, some causation factors for rear-end collisions were obtained. Next, accident analysis was performed through simulations based on these factors. The results indicated that many rear-end collisions are caused by momentary inattention during daily driving. Therefore, a collision avoidance assist system was developed that can be useful in these situations. In developing this system, a warning timing that does not interfere with the driver was set so as to reduce the potential for a less effective warning , and a system structure was adopted where delays in recognition and judgment are compensated for by automatic braking. The automatic brake activation method was investigated through calculations and actual vehicle tests. The activation timing was set so as not to interfere with normal driver operations, and the deceleration rate was set to assist the driver’s avoidance operations. As a result, the basis for a system to help reduce rear-end collisions was developed. Further development is needed to bring this kind of system to the point of practical application
By Yoshihiro URAI、Shoji ICHIKAWA、Kenji KODAKA、Makoto OTABE、Yoichi SUGIMOTO
Development of 7003 Aluminum Extrusions for Motorcycle Frame Applications
The 7003-T4 alloy as an acceptable material for production of a motorcycle frame was developed. In the development of the material, a designed experiment was planned by which nine 7003 alloy variants were cast and homogenized. The cast billets were extruded into hollow frame tubes on a production extrusion line and the natural aging response of the material was evaluated. The tendency for recrystallized grains at the surface of the extruded tubes was measured and confirmed to be at an acceptable level for painting. The reversion and recovery of mechanical properties during paint curing was evaluated and curing limits were established for mass production. From the results, parametric equations were derived to describe the relationships between mechanical properties, composition and natural aging time to insure design compliance. This development has resulted in a frame which is 35% lighter than the tubular steel construction applied to previous models.
By Junichi UEDA、Rowdy JOSEPH
Development of an Alloy for High Pressure Die Cast Pistons
High pressure die casting material was developed for the use of pistons in various mass-produced, small, general-purpose engines. This new material enables a significant reduction in casting tact time, allows a continuous line through the casting and machining processes, which is impossible to achieve by the permanent mold gravity die casting method (GDC), and contributes to production cost reduction. This material provides a material hardness of HRB65, which is equivalent to the material used in conventional methods, due to the high speed filling of the molten metal into the dies and the quick solidification of it. The material also accomplishes the high temperature durability requirements after undergoing a short T5 process. For the stabilization of the material properties in mass production, various alloy prototypes were produced and evaluated on strength, residual stress, seizure, microstructure, and actual engine durability in order to determine the optimal alloy composition.
By Yuko YOSHIMURA、Norimasa TAKASAKI、Takanori SATO、Kazuyoshi SATO、Yukio SUGIMOTO
Development of a Chromium-free Pretreatment System for Aluminum Bodies
A chromium-free surface treatment method was developed for aluminum bodies. By adding fluorine ions and iron complex compounds to the current zinc phosphate pretreatment bath, an improved zinc phosphate film is formed on aluminum. Also, increasing the manganese in the pretreatment bath improves the alkaline resistance properties of the zinc phosphate film. As a result of these changes, the zinc phosphate film has improved secondary adhesion after water conditioning and improved filiform corrosion resistance without using a chromium rinse. Therefore, chromium can be eliminated from the paint process of aluminum bodies. This, in turn, reduces environmental burdens previously posed.
By Toshiya NISHINO、Koichiro IZUMI