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The objective of this study was to investigate the change of relative local velocity in each pulley groove at sliding between the belt and pulleys for a metal-pushing V-belt type CVT where micro elastic slips were inevitably accompanied to transmit power, while the transmissions were widely adopted to provide comfortable driving by continuously automatically adjusting the speed ratio. Local changes of wrapping radial position and velocity of the belt in each pulley groove of the CVT were simultaneously measured by a potentiometer with a spinning roller in the experiments. The mechanical power generated by the AC motor was transmitted through the CVT unit from the driving axis to the driven axis as usual under practical conditions while the speed ratio was set to 1.0. Pulley clamping force was applied by oil pressure.

The tire is one of the most important parts, which influence the noise, vibration, and harshness of the passenger cars. It is well known that effect of rotation influences tire vibration characteristics, and earlier studies presented formulas of tire vibration behavior. However, there are no studies of tire vibration including lateral vibration on effect of rotation. In this paper, we present new formulas of tire vibration on effect of rotation using a three-dimensional flexible ring model. The model consists of the cylindrical ring represents the tread and the springs represent the sidewall stiffness. The equation of motion of lateral, longitudinal, and radial vibration on the tread are derived based on the assumption of inextensional deformation. Many of the associated numerical parameters are identified from experimental tests.

In this research, we aim at the construction of a steering cooperation-type front-wheel steering control system to reduce the rider's steering load by stabilizing the behavior of the motorcycle when turbulence in the direction of a roll occurs during low-speed driving. Finally, a front-wheel steering control system that considers cooperation with a rider's steering based on the experimental result is constructed, and the utility is verified by simulation.

This paper describes how use of multi-objective optimization of pulsating noise and backpressure improved an exhaust silencer for diesel drive equipment. Low frequency pulsating noise and backpressure were simultaneously predicted using one-dimensional fluid dynamics and acoustic analysis by BEM. In addition, an experiment was done to investigate the relation between high frequency noise including flow-induced noise and the dimensions of perforations in silencer pipes. Finally, a prototype of the exhaust silencer was built and examined in order to confirm the effects of these design methods mentioned. As predicted, exhaust noise was reduced without increasing backpressure.

In this study, the air suspension is newly applied to the engine mounting layout for getting the significant vibration isolation effect. In this case, the genetic algorithm so called GA is also applied for the optimization of many parameters, calculations of stiffness matrix and inverse stiffness matrix to prevent the coupled vibration of lateral and rolling modes and to obtain the displacement of each mounting point. As a result, inexperienced engineers can easily obtain the optimum engine mounting layout in a minute. By the confirmation test of FEM, the engine lateral vibration level at 25Hz dropped below 1/10 and its effect was significant.

To reduce tire/road noise, it is important to examine the noise generation mechanism. Noise generated by a rolling tire is mainly emitted from the tread block. However, it has recently been reported that smooth tires also generate noise recently. This paper remarks on a smooth tire vibration by rolling on the road. The vibration of a rolling smooth tire is mainly vibration excited from the road surface. It is difficult to measure the input from the road surface, so we measured the tire's vibration at the leading and trailing edges. Scan Laser Doppler Vibrometers were employed to measure the vibration of the tire tread.

This paper presents an analytical model for the prediction of piston secondary motion and the vibration due to piston slap. For the modeling of piston slap phenomenon, cylinder liner is modeled as a several spring-mass system that are connected by modal characteristics, and lubricant film between the piston and the cylinder is modeled as reaction force vectors which excite resonant mode of them. By comparing experimental results and analytical ones, the validity of the proposed model has been confirmed. The optimization of the piston skirt profile is also carried out with the analytical model, and it is confirmed that the round shape of the lower part of piston skirt is effective for the reduction of piston slap excitation.

In this study, a system to perform a parameter search of heavy-duty diesel engines is proposed. Recently, it has become essential to use design methodologies including computer simulations for diesel engines that have small amounts of NOx and SOOT while maintaining reasonable fuel economy. For this purpose, multi-objective optimization techniques should be used. Multi-objective optimization problems have several types of objectives and they should be minimized or maximized at the same time. There is often a trade-off relationship between objects and derivation of the Pareto optimum solutions that express the relationship between the objects is one of the goals in this case. The proposed system consists of a multi-objective genetic algorithm (MOGA) and phenomenological model. MOGA has strong search capability for Pareto optimum solutions. However, MOGA requires a large number of iterations.

The present study extends the recently developed HIDECS-GA computer code to optimize diesel engine emissions and fuel economy with the existing techniques, such as exhaust gas recirculation (EGR) and multiple injections. A computational model of diesel engines named HIDECS is incorporated with the genetic algorithm (GA) to solve multi-objective optimization problems related to engine design. The phenomenological model, HIDECS code is used for analyzing the emissions and performance of a diesel engine. An extended Genetic Algorithm called the ‘Neighborhood Cultivation Genetic Algorithm’ (NCGA) is used as an optimizer due to its ability to derive the solutions with high accuracy effectively. In this paper, the HIDECS-NCGA methodology is used to optimize engine emissions and economy, simultaneously. The multiple injection patterns are included, along with the start of injection timing, and EGR rate.

This paper describes a steady vibration of an engine supported by rubber and hydraulic mounts at a relatively low frequency range, assuming an engine is a rigid body. We identify dynamic characteristics of a hydraulic mount with respect to frequency and amplitude. The equation of motion is solved numerically by the Newton-Raphson method, treating the mount characteristics as functions of frequency and amplitude. The excitation test to simulate an engine shake and an idling vibration was performed using a mass block instead of an actual engine. During the engine shake, we observed that the amplitude dependency of hydraulic mounts strongly influences the vibration, while idling, we investigated rolling vibration especially for the case where the torque axis does not pass through the engine's center of gravity. The theoretical predictions agree closely with the experimental results in both engine shake and idling vibration tests.

In this paper, the simulation of the multi-objective optimization problem of a diesel engine is performed using the phenomenological model of a diesel engine and the genetic algorithm. The target purpose functions are Specific fuel consumption, NOx, and Soot. The design variable is a shape of injection rate. In this research, we emphasize the following three topics by applying the optimization techniques to an emission problem of a diesel engine. Firstly, the multiple injections control the objectives. Secondly, the multi-objective optimization is very useful in an emission problem. Finally, the phenomenological model has a great advantage for optimization. The developed system is illustrated with the simulation examples.

Generally, it is well known that road noise generated by vibration from automobile tires and suspensions can be reduced by changing the stiffness of the rubber mounts installed in the suspension systems. Such stiffness, however, is rarely changed to avoid riding discomfort and so on. In this paper, a stiffness optimization method for suspension system rubber mounts that reduces road noise, and improves riding comfort as well, is presented. In the process, Road Noise Contribution Analysis (RNCA) is applied to the target vehicle to specify the major factors of road noise. Furthermore, the suspension system of the vehicle is investigated by Sensitivity Analysis using Measured FRF data (SAMF) to identify the optimal stiffness combination of rubber mounts. As a result, an effective stiffness combination of two mounts is specified to reduce road noise and to improve riding comfort.

A new discrete model was developed in order to analyze the power transmitting mechanisms of a dry hybrid V-belt CVT not only at steady states but also at transitional states where the speed ratio was changing. Block tilting in the pulley was considered in the advanced numerical model as well as pulley deformation due to pulley thrust. The validity of the present model was well confirmed by comparing the calculated results on transmitting and normal forces with the former experimental results. The calculated results showed that both block tilting and pulley deformation meaningfully affected the pulley thrust ratio between the driving and the driven pulleys.