Automobile Wheel Alignment and Wheel Balancing

With over thirty years of experience in the design, development, and patenting of some products in the field of wheel alignment, the author shares his knowledge on the importance of wheel maintenance to the overall performance of a vehicle. From the ancient bullock carts to chariots to automobiles, wheels have undergone many changes to serve the purpose of mankind's mobility. Mobility is inevitable in today's life. A world without wheels is unimaginable. Every vehicle owner expects his tires to last longer and perform better. But improper wheel alignment and wheel balancing can drastically impact the wear and tear on a tire. This book walks the readers through the basics to techniques for wheel alignment on light vehicles, commercial vehicles, and trailers. In addition, illustrations present various types of tire wear and the cause of each. Finally, the author delves into tire safety from understanding how air pressure effects a tire to the importance of tire rotation.

Investigation of Tire Rotating Modeling Techniques Using Computational Fluid Dynamics

Fuel efficiency becomes very important for new vehicles. Therefore, improving the aerodynamics of tires has started to receive increasing interest. While the experimental approaches are time consuming and costly, numerical methods have been employed to investigate the air flow around tires. Rotating boundary and contact patch are important challenges in the modeling of tire aerodynamics. Therefore, majority of the current modelling approaches are simplified by neglecting the tire deformation and contact patch. In this study, a baseline CFD model is created for a tire with contact patch. To generate mesh efficiently, a hybrid mesh, which combines hex elements and polyhedral elements, is used. Then, three modeling approaches (rotating wall, multiple reference frame and sliding mesh) are compared for the modeling of tire rotation. Additionally, three different tire designs are investigated, including smooth tire, grooved tire and grooved tire with open rim. The predicted results of the baseline model agree well with the measured data. Additionally, the hybrid mesh show to be efficient and to generate accurate results. The CFD model tends to over predict the drag of a rotating tire with contact patch. Sliding mesh approach generated more accurate predictions than the rotating wall and multiple reference frame approaches. For different tire designs, tire with open rim has the highest drag. It is believed that the methodology presented in this study will help in designing new tires with high aerodynamic performance.

A Novel Longitudinal Speed Estimator for Four-Wheel Slip in Snowy Conditions

This article proposes a novel longitudinal vehicle speed estimator for snowy roads in extreme conditions (four-wheel slip) based on low-cost wheel speed encoders and a longitudinal acceleration sensor. The tire rotation factor, η, is introduced to reduce the deviation between the rotation tire radius and the manufacturer’s marked tire radius. The Local Vehicle Speed Estimator is defined to eliminate longitudinal vehicle speed estimation error. It improves the tire slip accuracy of four-wheel slip, even with a high slip rate. The final vehicle speed is estimated using two fuzzy control strategies that use vehicle speed estimates from speed encoders and a longitudinal acceleration sensor. Experimental and simulation results confirm the algorithm’s validity for estimating longitudinal vehicle speed for four-wheel slip in snowy road conditions.

Investigation on the Modeling of Tire Rotating Using Computational Fluid Dynamics

Fuel efficiency is very important when designing new vehicles. There is a continuous demand for lower fuel cost to customers. Many researchers have started to investigate the aerodynamics of tires. Since the experimental approaches are time consuming and costly, numerical methods have been developed to model the air flow around the tire. One of the challenges for modeling the tire is rotating boundary and contact patch. In the CFD model, both rotating and tire deformation have to be considered to get accurate predictions. However, most of the current methods neglect the tire deformation and contact patch. Therefore, in this study, three modeling approaches are compared for the modeling of tire rotation. They include rotating wall, multiple reference frame and sliding mesh. In CFD simulation, another challenge is mesh generation due to the sharp edge and large curvature around the contact patch. In order to generate mesh efficiently. A hybrid mesh which combines hex elements and polyhedral elements is used in this study. In addition, three different tire designs are investigated, including smooth tire, smooth tire with grooves and grooved tire with open rim. The results show that tire with open rim has the highest drag. Sliding mesh provides the most accurate predictions regarding of aerodynamic drag.

A Parametric Study of Air-Pumping Phenomenon in Tire Grooves Using Computational Fluid Dynamics

The tire/road interaction process results in generation of noise, which is transmitted and audible in the inside and outside of the car. In the recent years, the structural-borne noise in a tire has been extensively studied. However, very few studies have been conducted on air-borne noise. Various studies and indoor experimental measurements suggest that among all air-borne tire noise mechanisms, air-pumping mechanisms, i.e. rapid displacement of air near the tire/road contact patch, is the dominant source of noise for certain tires and operating conditions. This research focuses on studying air-pumping mechanisms and uses a previously developed computational model to predict air-borne noise generated using a hybrid approach. The basis of the hybrid approach is a direct prediction of near-field solution using compressible Navier-Stokes equations with turbulence modeling, combined with an analytical prediction of far-field acoustics using an acoustic model. Only the near-field acoustic characteristics are discussed in this paper. The tire rotation and groove deformations at the tire/road contact is modeled through mesh motion and prescribed deformation functions, thereby circumventing the need for coupling with a structural solver for fluid-structure interactions. The capability of the developed computational model in estimating the tire noise is shown and the effects of varying different parameters such as tire speed and geometry on the evolution of the estimated responses at various near-field receiver locations are studied.

Nonlinear Vehicle Dynamics and Trailer Steering Control of the TowPlow, a Steerable Articulated Snowplowing Vehicle System

The TowPlow is a novel type of snowplow that consists of a conventional snowplow vehicle and a steerable, plow-mounted trailer. The system is used to plow two typical traffic lanes simultaneously. In this paper, a nonlinear dynamic model of the TowPlow is developed for longitudinal, lateral, and yaw motions. The model considers nonlinearity through a modified Dugoff’s tire friction model, tire rotation dynamics, and quasi-static load transfer. The model is verified through steady-state and transient tests on an actual TowPlow system. A new snow resistance model is developed to allow simulation of the TowPlow in snow clearing operations. Then, active steering control of the trailer axle is derived with the goal of improving safety and efficiency of the TowPlow. The comparison of the simulation results between the controlled system and the uncontrolled system for cornering, slalom, up and down hill, and split friction coefficient braking maneuvers clearly demonstrates the efficacy of active steering control for the trailer axle of the TowPlow.

Perancangan Robot Line Follower Pemisah Benda Berdasarkan Warna Berbasis Mikrokontroler ATMega16

Line Follower Robot adalah sebuah robot otomatis yang dapat mengikuti garis yang dibuat dengan menggunakan bahan yang berwarna gelap (hitam) yang didukung oleh rangkain komponen elektronika yang dilengkapi dengan roda dan digerakan oleh motor. Pengendalian kecepatan sangat bergantung pada bata putaran dan pergesekan antara ban robot dengan lantainya. Robot tersebut dirancang untuk bernavigasi dan bergerak secara otomatis mengikuti sebuah alur garis yang dibuat. Untuk membaca garis, robot dilengkapi dengan sensor optik yang diletakkan diujung depan dari robot tersebut. Line Follower Robot ini memiliki jenis dan bentuk serta memiliki beberapa sistem penggerak dan pengendali sebagai pengatur kinerja yang beraneka ragam sesuai dengan kreatifita pembuatnya. Pada perancangan proyek line follower robot kali ini akan dibahas tentang pemisah warna benda dan dianalisi lebih dalam terhadap faktor suatu kecepatan robot dengan gerakan motor yang dikontrol oleh pengendali Prorportional Integral Derivative (PID) sehingga gerakan robot dapat dinamis sesuai dengan track yang akan diujikan.Line Follower Robot is an automated robot that can follow a line that is made using a dark -colored material (black) which is supported by a chain of electronics components are equipped with wheels and is moved by a motor. Speed control is very dependent on the brick and the friction between the tire rotation robot with the floor. The robot is designed to navigate and move automatically in response to a flow line made . To read the line, the robot is equipped with an optical sensor that is placed in front of the tip of the robot. Line Follower Robot has the type and shape and have some drive and control system as a regulator of diverse performance in accordance with the maker's creativity. In designing the project time line follower robot will be discussed on the object color separator and analyzed over a factor in the speed of movement of the robot with a motor that is controlled by the controller Proportional Integral Derivative (PID) so that the robot can move dynamical in accordance with a track that will be tested.

Uniformity: A Crucial Attribute of Tire/Wheel Assemblies

Good ride, acceptable comfort for passengers, is a required attribute for all road vehicles particularly automobiles and light trucks. The tire/wheel assembly is a critical component in providing good ride. Indeed, obtaining good ride was the crucial factor that drove the invention of and rapid popularization of the pneumatic tire. Today, the ride effect of tires is often thought of in two ways. The first is in terms of the transmission of vibration produced by the interaction of the tire with road surface irregularities, harshness. The second is in terms of tire structural irregularity generated energy transmitted during operation on a smooth road, uniformity. Both types of energy share the dynamic properties of the tire structure though they differ in source. This paper concentrates primarily on uniformity induced vibration particularly at the frequency of tire rotation, but does touch on harshness to a small degree, when the sharing of structural dynamics makes it appropriate. This review of the subject of force uniformity includes the effect of wheels, as wheels contribute to the vibration that reaches the vehicle spindle. Balance is touched on only as it affects force uniformity in well-balanced assemblies. This is not a treatise on balancing. A suggestion is made, which should, if practical, greatly improve the installed uniformity of tire/wheel assemblies.

Validation of a Belt Model for Prediction of Hub Forces from a Rolling Tire4

An integrated model is under development which will be able to predict the interior noise due to the vibrations of a rolling tire structurally transmitted to the hub of a vehicle. Here, the tire belt model used as part of this prediction method is first briefly presented and discussed, and it is then compared to other models available in the literature. This component will be linked to the tread blocks through normal and tangential forces and to the sidewalls through impedance boundary conditions. The tire belt is modeled as an orthotropic cylindrical ring of negligible thickness with rotational effects, internal pressure, and prestresses included. The associated equations of motion are derived by a variational approach and are investigated for both unforced and forced motions. The model supports extensional and bending waves, which are believed to be the important features to correctly predict the hub forces in the midfrequency (50–500 Hz) range of interest. The predicted waves and forced responses of a benchmark structure are compared to the predictions of several alternative analytical models: two three dimensional models that can support multiple isotropic layers, one of these models include curvature and the other one is flat; a one-dimensional beam model which does not consider axial variations; and several shell models. Finally, the effects of internal pressure, prestress, curvature, and tire rotation on free waves are discussed.