Abstract: This paper presents the experimental study of vibration generated by friction materials of an automotive disc brake system using brake test rig. Effects of silica sand particles which are available on the road surface as an environmental condition with a size varied from 150 μm to 600 μm are evaluated. Also, the vibration of the brake disc is examined against the friction material in humidity environment conditions under variable rotational speed. The experimental results showed that the silica sand particles have significant contribution on the value of vibration amplitude which enhances with increasing the size of silica sand particles at different speed conditions. Also, it is noticed that the friction material is sensitive to humidity and the vibration magnitude increases under wet testing conditions. Moreover, it can be reported that with increasing the applied pressure and rotational speed of the braking system, the vibration amplitudes decrease for all cases.
Abstract: In recent years, increasing the usage of railway transportations especially in developing countries caused more attention to control systems railway vehicles. Consequently, designing and implementing the modern control systems to improve the operating performance of trains and locomotives become one of the main concerns of researches. Dynamic braking systems is an important safety system which controls the amount of braking torque generated by traction motors, to keep the adhesion coefficient between the wheel-sets and rail road in optimum bound. Adhesion force has an important role to control the braking distance and prevent the wheels from slipping during the braking process. Cascade control structure is one of the best control methods for the wide range of industrial plants in the presence of disturbances and errors. This paper presents cascade control structure based on two forward simple controllers with two feedback loops to control the slip ratio and braking torque. In this structure, the inner loop controls the angular velocity and the outer loop control the longitudinal velocity of the locomotive that its dynamic is slower than the dynamic of angular velocity. This control structure by controlling the torque of DC traction motors, tries to track the desired velocity profile to access the predefined braking distance and to control the slip ratio. Simulation results are employed to show the effectiveness of the introduced methodology in dynamic braking system.
Abstract: In this paper, we present an activity diagram model for double-loop control self-adaptive braking system. Since activity diagram helps to improve visibility of self-adaption. We can easily find where improvement is needed on double-loop control. Double-loop control is adopted since the design conditions and actual conditions can be different. The system is reconfigured in runtime by using double-loop control. We simulated to verify and validate our model by using MATLAB. We compared single-loop control model with double-loop control model. Simulation results show that double-loop control provides more consistent brake power control than single-loop control.
Abstract: The Automobile Braking System has a crucial role for safety of the passenger and riding quality of the vehicle. The braking force mainly depends on normal reaction on the wheel and the co-efficient of friction between the tire and the road surface. Whenever a vehicle is loaded, the normal reaction on the rear wheel is increased. Thus the amount of braking force required to halt the vehicle with minimum stopping distance, is based on the pillion load on the vehicle. In this work, in order to vary the braking force in two wheelers, the mechanical leverage which operates the master cylinder is varied based on the pillion load. Thus the amount of braking force developed between ground and tire is varied. This optimum braking force on the disc brake helps in attaining the minimum vehicle stopping distance. In addition to that, it also helps in preventing sliding. Thus the system results in reducing the stopping distance of the two wheelers and providing a better braking efficiency than the conventional braking system.
Abstract: In this paper two different Antilock braking system (ABS) are simulated and compared. One is the ordinary hydraulic ABS system which we call it ABS and the other is Electromagnetic Antilock braking system which is called (EMABS) the basis of performance of an EMABS is based upon Electromagnetic force. In this system there is no need to use servo hydraulic booster which are used in ABS system. In EMABS to generate the desired force we have use a magnetic relay which works with an input voltage through an air gap (g). The generated force will be amplified by the relay arm, and is applied to the brake shoes and thus the braking torque is generated. The braking torque is proportional to the applied electrical voltage E. to adjust the braking torque it is only necessary to regulate the electrical voltage E which is very faster and has a much smaller time constant T than the ABS system. The simulations of these two different ABS systems are done with MATLAB/SIMULINK software and the superiority of the EMABS has been shown.
Abstract: Over the course of the past century, the global
automotive industry-s stance towards safety has evolved from one of
contempt to one nearing reverence. A suspension system that
provides safe handling and cornering capabilities can, with the help
of an efficient braking system, improve safety to a large extent. The
aim of this research is to propose a new automotive brake rotor
design and to compare it with automotive vented disk rotor. Static
structural and transient thermal analysis have been carried out on the
vented disk rotor and proposed rotor designs to evaluate and compare
their performance. Finite element analysis was employed for both
static structural and transient thermal analysis. Structural analysis
was carried out to study the stress and deformation pattern of the
rotors under extreme loads. Time varying temperature load was
applied on the rotors and the temperature distribution was analysed
considering cooling parameters (convection and radiation). This
dissertation illustrates the use of Finite Element Methods to examine
models, concluding with a comparative study of the proposed rotor
design and the conventional vented disk rotor for structural stability
and thermal efficiency.
Abstract: The anti-lock braking systems installed on vehicles
for safe and effective braking, are high-order nonlinear and timevariant.
Using fuzzy logic controllers increase efficiency of such
systems, but impose a high computational complexity as well. The
main concept introduced by this paper is reducing computational
complexity of fuzzy controllers by deploying problem-solution data
structure. Unlike conventional methods that are based on
calculations, this approach is based on data oriented modeling.
Abstract: We see in the present day scenario that the Global
positioning system (GPS) has been an effective tool to track the
vehicle. However the adverse part of it is that it can only track a
vehicle-s position. Our present work provides a better platform to
track and disable a vehicle using wireless technology. In our system
we embed a microcomputer which monitors the series of automotive
systems like engine, fuel and braking system. The external USB
modem is connected with the microcomputer to provide 24 x 7
internet accesses. The microcomputer is synchronized with the
owner-s multimedia mobile by means of a software tool “REMOTE
DESKTOP". A unique username and password is provided to the
software tool, so that the owner can only access the microcomputer
through the internet on owner-s mobile. The key fact is that our
design is placed such that it is known only to the owner.
Abstract: A robust wheel slip controller for electric vehicles is
introduced. The proposed wheel slip controller exploits the dynamics
of electric traction drives and conventional hydraulic brakes for
achieving maximum energy efficiency and driving safety. Due to
the control of single wheel traction motors in combination with a
hydraulic braking system, it can be shown, that energy recuperation
and vehicle stability control can be realized simultaneously. The
derivation of a sliding mode wheel slip controller accessing two
drivetrain actuators is outlined and a comparison to a conventionally
braked vehicle is shown by means of simulation.