A new method in the identification of noise and vibration characteristics of automotive disk brakes in the low frequency domain

\u3cp\u3eNoise and vibration characterization is an important benchmark to reduce brake noise. Brake noise and vibration measurement is commonly done on an actual vehicle or on a brake dynamometer. A full scale brake dynamometer takes into account the attached mass which resembles the mass of a quarter scale vehicle. This paper proposes a testing method which eliminates the need for attached masses. This is achieved through the scaling of the brake system parameters to accommodate the loss of mass and produce similar conditions to those in actual braking. The measurement of noise and vibration is measured simultaneously and an FFT is performed to identify the frequencies of noise and vibration. An experimental modal analysis (EMA) is done to obtain the frequencies which the brake system tends to produce as a validation to the proposed method. It is shown that through this method the noise and vibration characteristics of the brake system and the unstable frequencies can be identified.\u3c/p\u3

A predictive tool to evaluate disk brake squeal using a fully coupled thermo-mechanical finite element model

\u3cp\u3eThis paper presents a new integrated approach to the analysis of brake squeal modelling. It focuses on developing a validated thermo-mechanical finite element model by taking full account of the effect of thermal loading on the structural response of the brake. An integrated study involving time-dependent non-linear contact and a fully coupled transient thermal analysis are carried out to provide the contact and temperature distribution within the brake before executing an instability study using the complex eigenvalue technique. The results, in turn, demonstrate the fugitive nature of brake squeal through the system eigenvalues that are extracted throughout the braking period.\u3c/p\u3

Suspension kinematic analysis of UTeM’s FV Malaysia electric vehicle racing car

The purpose of this paper is to investigate the kinematic performance of students’ racing car, namely UTeM’s FV Malaysia Electric Vehicle. An elasto-kinematic analysis approach is used to predict the car’s performance during straight line drive and curvature drive. Two suspension design factors involved in this analysis are toe and camber. The kinematic analysis is iterated using the multibody dynamics simulation. The suspension performance is then compared to the standard SLA suspension. The result shows that the front suspension design does not follow the good C shaped toe and camber curves for the SLA suspension type. However, the suspension design of the rear suspension performs well as it follows the good SLA performance curve. \u3cbr/\u3

Numerical prediction of brake friction pair vibration using dynamics green's function

\u3cp\u3eThe prediction capability of the brake system vibration is still unable to cover a broad range of frequencies. Current predictive models are contained within a particular range to cater for specific vibration types. Therefore, a numerical model which could make predictions in a broad spectrum range is required. The model presented in this paper is derived with such aim. The model is derived from the interaction between the friction pairs with the focus on the brake pad. The brake disc is simplified as a travelling sinusoidal wave. Where else, the brake pad is modelled as a Euler- Bernoulli beam with forces and distributed friction acting upon it. The Dynamic Green Equation applied in solving the derived friction pair equation. The outcome of the developed model predicted brake pad vibrational frequency coinciding accurately with brake dynamometer experimental results. Therefore, the validated model could be a viable prediction and study tool for various brake system parameters.\u3c/p\u3

An exploration on new product development process of Malaysian small-sized automaker

\u3cp\u3eThis paper focused on the identification and description of a new product development (NPD) approach adopted by one of the smallsized car producers in Malaysia. The NPD processes for European, Japanese and American auto makers have been studied and discussed in literature. However, the business strategy of NPD approach of small-sized car makers remains unidentified and less understood. This research involved semistructured face-to-face interview sessions at several occasions with senior project managers and development team members, a senior product planning manager together with a selected first tier vendor. The information obtained through literature on the NPD process was used as secondary data to correlate with the data obtained from the primary source (interview). Results derived from both sources later were used to completely identify and describe the NPD process of this car maker. The results indicated that the NPD process of the automaker was not that distinct as compared with the generic product development of others. In addition, the findings also showed the automaker has adopted the concurrent engineering practices in the product development process. This paper also highlighted the importance of a formal NPD with regard to the frequency of the new product introduction and managing risks and uncertainty.\u3c/p\u3

Numerical analysis of spring stiffness in vehicle design development stage

\u3cp\u3eThis paper reported the numerical analysis technique to investigate the influence of spring stiffness in automotive suspension towards improving the vehicle ride and performance. There are three type of spring’s stiffness categories which have been used to conduct the numerical analysis; soft, medium and hard. Using the full vehicle model and front suspension mathematical model, the study on rolling analysis for these three type of spring stiffness parameter towards the effect of the suspension total roll rate, tramp rate, roll centre height, roll centre lateral as the vehicle subjected to go through the longitudinal and cornering test. The results from the numerical simulation was then applied to the real vehicle model for field test. The outcome from the present work highlight the important of spring stiffness investigation during the vehicle design stage to improve the vehicle ride and performance.\u3c/p\u3

Position tracking of automatic rack and pinion steering linkage system through hardware in the loop testing

\u3cp\u3eVehicle handling behavior is much influenced by the performance of steering system and its mechanism. Steering linkage play a very important role in maneuvering of a vehicle. In this paper, a set of kinematic relations of rack and pinion steering linkage system are modeled in MATLAB Simulink environment based on kinematic model equations is presented to study the relationship between steering wheel and tire angle. A Hardware-in-the-loop Simulations (HILS) test rig with actual rack and pinion mechanism has been set up using real time software environment from MathWorks namely xPC Target, LVDT and encoder sensors installed for data measurement at various steering angle. Results from simulation model demonstrate a linear pattern occurred from maximum lock-to-lock steering wheel angle and it is closely follow the sine input trend through HILS experiment with acceptable error.\u3c/p\u3

Simulating autonomous driving styles: accelerations for three road profiles

This paper presents a new experimental approach to simulate projected autonomous driving styles based on the accelerations at three road profiles. This study was focused on the determination of ranges of accelerations in triaxial direction to simulate the autonomous driving experience. A special device, known as the Automatic Acceleration and Data controller (AUTOAccD), has been developed to guide the designated driver to accomplish the selected accelerations based on the road profiles and the intended driving styles namely assertive, defensive and light rail transit (LRT). Experimental investigations have been carried out at three different road profiles (junction, speed hump, and corner) with two designated drivers with five trials on each condition. A driving style with the accelerations of LRT has also been included in this study as it is significant to the present methodology because the autonomous car is predicted to accelerate like an LRT, in such a way that it enables the users to conduct activities such as working on a laptop, using personal devices or eating and drinking while travelling. The results demonstrated that 92 out of 110 trials of the intended accelerations for autonomous driving styles could be achieved and simulated on the real road by the designated drivers. The differences between the two designated drivers were negligible, and the rates of succeeding in realizing the intended accelerations were high. The present approach in simulating autonomous driving styles focusing on accelerations can be used as a tool for experimental setup involving autonomous driving experience and acceptance

The exploration of autonomous vehicle driving styles : preferred longitudinal, lateral, and vertical accelerations

This paper describes a new approach in exploring preferred driving styles for autonomous vehicles through simulation of autonomous driving in real road conditions. A Wizard experiment with an equipped car was conducted to investigate the preferences of people with different driving styles, assertive and defensive, for three autonomous vehicle driving styles (defensive, assertive and light rail transit), inducing different acceleration forces, at three different road profiles. Subjective and objective measurements were collected. The results show that the defensive driving style was preferred and there were variations between participants related to their own driving style. The results indicate that the preferences of assertive drivers for the driving style of an autonomous vehicle may not match their own driving style. Yet, users of future autonomous vehicles should be able to indicate and adjust the driving behavior of an autonomous vehicle to their own preferences in order to maximize comfort in travelling experience

The identification of Malaysian driving styles using the multidimensional driving style inventory

A study was conducted to investigate the driving styles within the geographical region of Malaysia. The first part of the study determined Malaysian drivers’ driving styles using the Multidimensional Driving Style Inventory approach. Respondents had various backgrounds in terms of age, gender and experience of driving. A statistical factor analysis was done for 338 respondents revealing four driving styles; careful, risky, anxious-dissociative and angry. In addition, a comparison with previous findings from Netherlands and Israel was also done in this study. The next part of the study focused on the associations of these driving styles with two personality traits (sensation seeking and desire for control), sociodemographic factors and experience of driving. The last part of the paper discusses the relevance of the study against the background of future automotive developmen