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The design of the newly developed Toyota AZ series 4 cylinder engine has been optimized through both simulations and experiments to improve heat transfer, cooling water flow, vibration noise and other characteristics. The AZ engine was developed to achieve good power performance and significantly reduced vibration noise. The new engine meets the LEV regulations due to the improved combustion and optimized exhaust gas flow. A major reduction in friction has resulted in a significant improvement in fuel economy compared with conventional models. It also pioneered a newly developed resin gear drive balance shaft.

Seat Effective Amplitude Transmissibility (SEAT) values can be obtained from direct measurements at seat track and top or estimated from transmissibility data and seat track input. Vertical transmissibility was measured for sixteen seats and six subjects on the Ford Vehicle Vibration Simulator, and these 96 functions used to estimate the seat top response for rough road input. SEAT values were calculated, and good correlation to values computed from direct seat top measurements obtained (R2 of 0.86). Averaging transmissibilities and direct seat measurements over the 6 subjects to obtain correlations for the 16 seats improved R2 to 0.94, validating this approach.

The ride values of seven cars(six passenger car and one RV car) are evaluated for 4 subjects based on the vibration of the bodies. And the seat qualities are investigated with the SEAT(seat effective amplitude transmissibility) value. The evaluated values are arranged as DB in html files. Since one of the most important parameters for ride comfort is the level and duration of the root mean square acceleration experienced, the acceleration responses of subjects are measured at 8 points on their bodies(3 Translational axes on the seat surface, 3 translational axes at the feet and 2 axes(x,z) at the backrest) when the subjects are excited by driving a vehicle on the road. The ride values such as the overall ride value, the component ride values and the seat effective amplitude transmissibility based on acceleration root mean square are evaluated for different seven vehicles using frequency weighting functions and axis multiplying factors.

Industrial computed tomography has developed from a medical technology base. As such industrial systems reflect medical requirements which are not necessarily efficient for industrial applications. The Tangential CT scanner is truly a volume scanner system designed for industrial inspection. The part motions required for CT data collection are efficient and fit well with part handling motions normally used by industrial inspection equipment. The part enters the system, moves through the scanning station and exits with a single linear motion. The detectors are designed for industrial applications to maximize sensitivity while minimizing electronic and x-ray scatter noise. The system can be easily programed for different size parts with different resolution requirements. The result is a data set that is acquired efficiently and has the required volumetric data for Flaw detection, Metrology or Reverse Engineering.

The purpose of this study was to determine the adequacy of butt and T-shape welds in predicting the burst strength of realistic nylon 66 parts. This study assessed the effects and interactions of vibration welding process parameters using a central composite design of experiment on selected part geometries. The results confirm that butt-welded plaques exhibit higher weld strengths under tensile load than T-welded plaques and simple cup-plaque parts. These latter two welds were typically 50% weaker than butt welds. A comparison of weld strengths suggests that the lab-scale T-joint geometry more closely models more complex vibration welded parts.

A mathematical model for a hydraulic power steering system was constructed and numerical analysis was performed for self-excited vibration caused by rapid steering in the power steering system. From the examination, the guide of the prevention against the vibration was derived, such as positioning the rather long hose at near the power steering gear in the supply line, and the mechanism of the prevention was clarified. Moreover, the mathematical model and the guide of the prevention were verified by bench tests.

Even if the brake judder is an often analyzed problem from the mechanical point of view, its influence on the hydraulic elements such as the braking and steering systems is not fully established. The aim of this paper is to present models of the hydraulic components connected to a model of the front suspension and thus having a view of the influence of these hydraulic elements on the amplification of the brake judder vibrations. Each models of the front suspension, the braking circuit and the hydraulically powered steering assistance are validated separately versus or measurements or other softwares. The introduction of the disc thickness variation (DTV) generates the braking judder of interest. Some first simulation results are shown to see couplings or influence of hydraulic components on vibration propagations.

This paper presents a new motor current control strategy for Electric Power Steering (EPS) to reduce current fluctuation. Such current fluctuation may cause undesirable steering torque ripple and acoustic noise, if an inexpensive microprocessor is used. Using a DC-motor, current fluctuation associated with change in the battery voltage, etc., may occur. We have developed a new current control strategy which effectively alleviates current fluctuations of the motor without using higher performance microprocessors. The new controller is based on the estimation of disturbance voltage and compensation for this disturbance voltage. We have bench-tested the performance of this control strategy and confirmed that current fluctuation is reduced below that using conventional PI controller. The PI gain for the proposed controller is the same as that for the conventional controller.

Front road wheel toe dynamics directly affects tire wear and steering wheel vibration, which in turn negatively impacts customer satisfaction. Though static toe can be preset in assembly plants, the front road wheels can vibrate around steering axes or kingpin axes due to tire mass unbalance and nonuniformity. The frequency of the vibration depends on the wheel size and vehicle speed, while the amplitude of the vibration is not only dictated by the tire forces, but also by suspension and steering parameters. This paper presents a study on the sensitivities of the front road wheel toe dynamics to the parameters of a short-long-arm suspension (SLA) and a parallelogram steering system. These parameters includes hard point shift, steering gear compliance, gear friction, control arm bushing rates, friction in control arm ball joints, and compliance in tie rod outboard joints.

Recently, EPS (Electrical Power Steering) is being widely applied in order to reduce fuel consumption and decrease installation problems of the power steering system. EPS also decreases development time and cost of the steering system due to its ease of tuning. As we mentioned in the former paper “2000-01-0824”, the larger output motors are required. Upon developing the higher output motors, Mitsubishi realized that the EPS Systems brought about high acoustic noise, vibration, large torque ripple and friction loss. We have developed a very silent motor based on our unique technology. This involved a very unique electromagnetic force and mechanical vibration analysis method. Our super silent motor is so quiet, that the occupants of a vehicle can not distinguish the motor noise even when the motor is installed in the vehicle cabin.

A method for predicting body deformation during operation, which cannot be measured by conventional methods, has been developed. The method creates a body model based on the characteristics extracted by modal analysis of the results of a vibration testing of an actual vehicle. The model is combined with a suspension model, using multibody dynamics software, and body deformation calculations are performed. In this paper, the influence of body deformation on vehicle controllability and stability is studied and the usefulness of the method is verified.

Using a finite element approach, a technique for optimization of an exhaust system design was developed. This technique involved the creation of the parameterized model, implementation of the loading and finally the optimization of the model. In the creation of the finite element model, pipe elements were used. Parameters were assigned to the structure using coordinate relations between nodes, instead of the positions of the nodes in coordinate space. The model was then verified using modal analysis. A random vibration analysis was used as a loading criterion for the model, as well as static gravitational loading. The optimization of the design focused primarily on the shape characteristics of the structure and secondarily on each component thickness. Using only thickness parameters, a 15% reduction of the weight of the system was achieved, with an additional 2-3% decrease in weight possible through shape optimization.

Product development processes generate large quantities of experimental and analytical data. The data evaluation process is usually quite lengthy since the data needs to be extracted from a large number of individual output files and arranged in suitable formats before they can be compared. When the data quantity grows extremely large, manual extraction cannot be done in a limited timeframe. This paper describes a set of tools developed by MTS engineers to automatically extract the desired information from a large number of files and perform data post-processing. The tools greatly improved both speed and accuracy of the evaluation process during the development of a sound quality-based end-of-line inspection system for seat tracks [1]. It allowed engineers to quickly gather a comprehensive understanding of the relative importance of individual design parameters and of their correlation to the subjective perception of the sound quality of the seat track.

This paper presents some of Renault's knowhow in modelling aerodynamic flows obtained in an operational environment on development configurations. The methodologies, developed from Navier Stokes equations averaged for turbulence, are used indeed to size openings and body elements, determine positions and optimize the geometry of the various air inlets and outlets, reduce pressure losses in the cab ventilation circuits, improve exchanger efficiency, optimize the underhood architecture devise encapsulation solutions, model windscreen de-icing, reduce aerodynamic noise and improve the understanding of certain physical processes associated with fouling.

A new Tyre Model suitable for Tyre Dynamic Representation on uneven road and in general high-frequency handling excitations has been developed in a multi-body code. The tyre representation is both empirical and physical: contact forces between contact patch and road are achieved from numerical Pacejka formulation but applied to a physical structure representation instead of to a simple spring-damper element. Such a physical tyre model enables the simulation of the dynamics up to 100 Hz and vibration due to high frequency handling manoeuvre or on uneven road contact excitation. Validations with experimental results are of course included both for tyre tests on suitable testrigs and for full vehicle manoeuvres.

0 The accuracy of nowadays CAE tools for simulation of sound pressure level distributions in the passenger compartment of vehicles is not satisfactory because of the simplify models, especially with regard to the description of common passive acoustical treatments. This report describes the application of the TREASURI method on a complete vehicle, equipped with sound deadening treatment sound absorbing material sound insulation treatment and interior trim material (e.g. instrument panel, seats, center console). In order to validate the method, the simulation results were compared with the measurement results from the corresponding vehicle. The evaluation shows that the TREASURI approach yields considerable improvements in simulation accuracy up to 300 Hz compared to classical approaches [1]. This method now enables reliable predictions of acoustical influence on structural modifications and changes of the sound package.

This paper analyzes hysteresis (HCR), delta modulation (DCR), and pulse width modulation (PWMCR) current regulators for switched reluctance machines. The current regulators are implemented in real-time for a 6/4 3-phase 15 kW switched reluctance machine (SRM). The comparative study of the performance of the current regulator is focused on the current transient response, deviation from the current reference, acoustic noise, and vibration for soft chopping and hard chopping mode of operation.

Switched Reluctance Motor (SRM) mainly has two advantageous characteristics such as no magnet and simple construction. These characteristics contribute lower cost and higher reliability compared with other motor systems such as brushless permanent magnet motors or induction motors. However, acoustic noise and output torque ripple should be improved when the SRM is applied to a traction system for passenger electric vehicle since these characteristics directly affect vehicle quietness and drivability. In this paper, we describe a system configuration of the SRM traction system for passenger electric vehicle. The SRM traction system includes an electric motor, transmission gears and power inverter module. Then, an approach to improve acoustic noise and output torque ripple is introduced. Generation mechanisms of acoustic noise and output torque ripple are analyzed.

Brake squeal noise is studied in this paper by feed-in energy analysis. Based on the closed-loop coupling brake model, the computation method of feed-in energy is derived for the system squeal mode. The amount of feed-in energy can indicate the degree of squeal tendency of the brake system. Feed-in energy analysis can clearly reveal the influence of some structural parameters on brake noise, such as coefficient of friction, the geometric shape and stiffness of pads, and key substructure modal shape. It also can help to analyze the structure modification to eliminate brake squeal.

This paper describes a new process for vibrating large automotive bucks (body in white) to 500 Hz and higher. This process utilizes multiple electrodynamic shakers driving large magnesium mounting plates. The vertical axis utilizes three large head shakers driving a common magnesium plate 12 ft. long x 4 ft. wide. The shakers are dynamically matched, and the input a feedback signal is paralleled. This approach coupled with a closed loop digital vibration controller offers excellent dynamic uniformity to better than 500 Hz to the buck under test. The fore/aft and lateral utilize two shakers driving a common 12 ft. x 4 ft. magnesium slip plate. In the lateral, the shakers are side by side; and in the fore/aft, they are in a push-pull configuration. This approach offers control and spectrum tailoring to 500 Hz or higher. This method is dynamically superior over single shaker input and four poster shakers because the buck under test is seeing homogeneous vibration to 500 Hz.