Electromagnetic Braking System 5b1ku

ELECTROMAGNETIC BRAKING SYSTEM

BACHELOR OF ENGINEERING IN PRODUCTION AND INDUSTRIAL ENGINEERING

PEC UNIVERSITY OF TECHNOLOGY CHANDIGARH

2016

A PROJECT SUBMITTED BY ARPIT DHIMAN (14109006) GUNEEV SINGH BATTH (14109016) DILRAAJ SINGH MAND (14109032) SACHIN DUTT (14109046) NITESH KALRA (14109053)

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CANDIDATE’S DECLARATION

I hereby certify that the work which is being presented in the dissertation entitled “Electromagnetic Braking System” in the partial fulfilment of the requirements for the award of the Bachelor of Engineering in Production and Industrial Engineering and submitted in the Department of Production and Industrial Engineering of the PEC University of Technology, Chandigarh, is an authentic record of my own work carried out during the period from July 2016 to November 2016 under the Supervision of Prof. Rahul O. Vaishya. The matter presented in this project has not been submitted by me for the award of any other degree of this or any other Institute.

5-December-2016

(Candidate Name) Arpit Dhiman Guneev Singh Batth Dilraaj Singh Mand Sachin Dutt Nitesh Kalra

This is to certify that the above statement made by the candidate is correct to the best of our knowledge

Dr. Rahul Vaishya PEC University of Technology Chandigarh 05-December-2016

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Acknowledgements

The completion of this project could not have been possible without the help of our professors, Lab assistants and everyone who has been there for us whenever required. Their contributions are sincerely appreciated and gratefully acknowledged. However, the group would like to express their deep appreciation and indebtedness particularly to the following: Prof. Rahul O. Vaishya, Prof. Dina Nath Dhiman, Prof. Mohit Garg, Prof. Rajeev Verma and Jasbir Sir for their .

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Table of Contents 1. Abstract…………………………………..………………………………..……………………………Page No-5 2. Introduction………………………………..………………………………..………………………. Page No-6 3. Literature review………………………………..………..………………………..……………… Page No-8 4. Problem Statement………………………………..……….………………………..……………Page No-10 5. Solution Approach………………………………..………..………………………..……………Page No-11 6. Principle of Braking System…………………………….…..……………………………..…Page No-12 7. Components Used………………………………..…………..……………………..…………….Page No-16 8. Infrared Sensor………………………………………………………………………….…………Page No-22 9. Methodology………………………………..………………….……………..…………………… Page No-26 10. Design Optimization and Calculations………………..………………..…………..…… Page No-28 11. Advantages and Disadvantages…………………………..……..…………………………. Page No-30 12. Future Scope………………….……………..………………………………..…………………… Page No-31 13. Conclusion……………………..…………..……………………………..………………………… Page No-32 14. References…………………………………………………………………………………………...Page No-33

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ABSTRACT The principle of braking in road vehicles involves the conversion of kinetic energy into heat. This high energy conversion therefore demands an appropriate rate of heat dissipation if a reasonable temperature and performance stability are to be maintained. While the design, construction, and location features severely limit the heat dissipation function of the friction brake, electromagnetic brakes work in a relatively cool condition and avoid problems that friction brakes face by using a totally different working principle and installation location. By using the electromagnetic brake as supplementary retardation equipment, the friction brakes can be used less frequently and therefore practically never reach high temperatures. The brake linings thus have a longer life span, and the potential ‘brake fade’ problem can be avoided. It is apparent that the electromagnetic brake is an essential complement to the safe braking of heavy vehicles.

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INTRODUCTION Brake A vehicle brake is used to slow down a vehicle by converting its kinetic energy into heat. Most commonly brakes use friction between two surfaces pressed together to convert the kinetic energy of the moving object into heat, though other methods of energy conversion may be employed. For example regenerative braking converts much of the energy to electrical energy, which may be stored for later use. Other methods convert kinetic energy into potential energy in such stored forms as pressurized air or pressurized oil. Eddy current brakes use magnetic fields to convert kinetic energy into electric current in the brake disc, fin, or rail, which is converted into heat. Still other braking methods even transform kinetic energy into different forms, for example by transferring the energy to a rotating flywheel. Types of Brakes: 1) Friction Brake 2) Electromagnetic Brake

Friction Brake A friction brake is a type of automotive brake that slows or stops a vehicle by converting kinetic energy into heat energy, via friction. The heat energy is then dissipated into the atmosphere. In most systems, the brake acts on the vehicle's wheel hubs, but some vehicles use brakes which act on the axles or transmission. Friction brakes may be: 1. Drum Type 2. Disc Type

Drum Brake A drum brake is a vehicle brake in which the friction is caused by a set of brake shoes that press against the inner surface of a rotating drum. The drum is connected to the rotating road wheel hub.

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Disc Brake The disc brake is a device for slowing or stopping the rotation of a road wheel. A brake disc (or rotor in U.S. English), usually made of cast iron or ceramic, is connected to the wheel or the axle. To stop the wheel, friction material in the form of brake pads (mounted in a device called a brake caliper) is forced mechanically, hydraulically, pneumatically or electromagnetically against both sides of the disc. Friction causes the disc and attached wheel to slow or stop.

Electromagnetic Brake 1) Electromagnetic brakes slow an object through electromagnetic induction, which creates resistance and in turn either heat or electricity. Friction brakes apply pressure on two separate objects to slow the vehicle in a controlled manner. 2) In locomotives, a mechanical linkage transmits torque to an electromagnetic braking component. 3) Trams and trains use electromagnetic track brakes where the braking element is pressed by magnetic force to the rail. They are distinguished from mechanical track brakes, where the braking element is mechanically pressed on the rail. 4) Electric motors in industrial and robotic applications also employ electromagnetic brakes. 5) Recent design innovations have led to the application of electromagnetic brakes to aircraft applications. In this application, a combination motor/generator is used first as a motor to spin the tires up to speed prior to touchdown, thus reducing wear on the tires, and then as a generator to provide regenerative braking.

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LITERATURE REVIEW 1. Stephen Z. Oldakowski, Bedford, Ohio(2002): A magnetic brake provides braking or locking capability and is remotely controlled by electric power. The magnetic brake comprises a rotatable shaft and a brake disc mounted on the shaft. A non-rotating core housing assembly located around the shaft includes a permanent magnet and a bipolar solenoid. A magnetic armature adjacent to the core housing assembly is capable of movement toward the core housing assembly and toward and into engagement with a brake disc to prevent rotation of the shaft. A spring urges the armature away from the core housing assembly and into engagement with the brake disc. The brake does not use any electric power to maintain the brake in the set mode with the rotating shaft fully locked or in the released mode with the rotating shaft fully released. The permanent magnet is of sufficient strength to hold the armature against urging of the spring until an opposite polarity is supplied by the solenoid. 2. Karl Erny, Holzhausem(1999): An elevator drive has a brake device with compression springs to actuate brake levers, and brake linings on a brake drum creating a braking force. A sensor is provided to detect the movement of a brake magnet armature tappet. A bracket is attached to the brake magnet tappet on one end and a distance piece carrying the sensor housing is arranged on the other end. A restoring lug is attached to the existing mechanical indicator. A monitor evaluates the sensor signal and turns off the elevator drive in the event of dangerous operational states via a safety circuit. The system allows the state of the brake device to be monitored. The more the brake linings wear off due to abrasion, the smaller the distance between the armature and the brake magnet housing. If the armature is in with the brake magnet housing, the braking ability of the brake linings is completely void. 3. Hung-Chi Wu, 958-2, Ghung Shan Rd., Tao-Yuan, Taiwan(2003): This invention relates to an adjustable magnetic brake and in particular to one including an aluminum fan, a magnetic conducting ring enclosing the aluminum fan, a permanent magnet disposed within the aluminum fan, a fixing seat for keeping the permanent magnet in position, a sliding seat mounted in the fixing seat and provided with a bearing, a housing, bolts provided on one side of the fixing seat and extending out of the housing, a mounting plate connected with the bolts and a wire connected with the mounting plate such that when the wire is pulled outwards, the permanent magnet will be moved outwards. 4. Jae-Woong Lee, Seoul, Rep. of Korea(2003): Disclosed is a magnetic brake system for a vehicle. comprising: a plurality of brake disk solenoids for generating the magnetic force; a plurality of brake pad solenoids for generating the magnetic force; a braking 8

sensor for detecting whether a brake pedal is applied; a wheel speed sensor for detecting wheel speed; a magnetic polarity sensor for detecting magnetic polarity of the brake disk solenoids; and a control unit for controlling the brake pad solenoids using signals from the braking sensor. The wheel speed sensor and the magnetic polarity sensor. 5. Albert E. Miller, Dayton, Ohio(2001): This invention relates to a fishing reel and more particularly to an improved type of reel having a compensated magnetic brake means for preventing backlash or overrunning of the spool. An object of this invention is to provide a reel which is inexpensive to manufacture and which is durable and trouble-free in operation. Still another object of this invention is to provide an improved form of magnetic brake having spring means for modifying the brake action. A further object of this invention is to provide a fishing reel which is smooth in operation and which is readily adjustable to desired degrees of drag or braking effect. Further objects and advantages of the present invention reside in the construction and combination of parts and in the mode of operation as will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of the present invention is clearly shown.

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PROBLEM STATEMENT 

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The conventional brake system consists of a lot of moving parts and is based on the principle of friction thus a lot of forces dissipated in the form of heat due to friction and the links involved. Disc brakes work using the same basic principle as the brakes on a bicycle: as the caliper pinches the wheel with pads on both sides, it slows the vehicle. Drum brakes consist of a heavy flat-topped cylinder, which is sandwiched between the wheel rim and the wheel hub. The inside surface of the drum is acted upon by the linings of the brake shoes. Air brakes use standard hydraulic brake system components such as braking lines, wheel cylinders and a slave cylinder similar to a master cylinder to transmit the air-pressureproduced braking energy to the wheel brakes. All the above mentioned convectional brakes have two chief problems one is the wear and tear and other is unnecessary excessive temperature in the service is attained. Excessive heating of brakes can result in fade, it causes temporary changes in the friction as they get hotter. Normally efficiency is regained when they cool again Brake pads and linings also wear away faster at higher temperatures.

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SOLUTION APPROACH 

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As seen in the above-mentioned problem with the convectional brakes the problem is arises due to the friction between two or more rubbing parts. Hence electromagnetic brakes can be used as a replacement which is totally frictionless. In Electromagnetic Braking System, there is no question of wear and tear of parts and unnecessary temperature issues as there is no friction in this braking system. This results in stable efficiency of the braking system for a longer service span. In addition, it results in longer life span of the braking system without any wear and tear. This also gives the answer for the replacement of cooling system. Therefore, the electromagnetic brakes give the answers for the questions that arise in the convectional braking systems.

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PRINCIPLE OF BRAKING SYSTEM The principle of braking in road vehicles involves the conversion of kinetic energy into thermal energy (heat). When stepping on the brakes, the driver commands a stopping force several times as powerful as the force that puts the car in motion and dissipates the associated kinetic energy as heat. Brakes must be able to arrest the speed of a vehicle in short periods of time regardless how fast the speed is. As a result, the brakes are required to have the ability to generating high torque and absorbing energy at extremely high rates for short periods of time.

Characteristics: Brakes are often described according to several characteristics including:  Peak force is the maximum decelerating effect that can be obtained. The peak force is often greater than the traction limit of the tires, in which case the brake can cause a wheel skid.  Continuous power dissipation Brakes typically get hot in use, and fail when the temperature gets too high. The greatest amount of power (energy per unit time) that can be dissipated through the brake without failure is the continuous power dissipation. Continuous power dissipation often depends on e.g., the temperature and speed of ambient cooling air.  Fade As a brake heats, it may become less effective, called brake fade. Some designs are inherently prone to fade, while other designs are relatively immune. Further, use considerations, such as cooling, often have a big effect on fade.

Existing Condition A. Brake fading effect The conventional friction brake can absorb and convert enormous energy values (25h.p. without self-destruction for a 5-axle truck, Reverdin1974), but only if the temperature rise of the friction materials is controlled. This high energy conversion therefore demands an appropriate rate of heat dissipation if a reasonable temperature and performance stability are to be maintained.

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B. Brake fluid leakage If your vehicle has worn brake pads or brake shoes, the fluid level in your brake fluid reservoir will be low. But let's say you have relatively new brake pads and you recently topped-off your brake reservoir only to notice a few days later that the fluid level has dropped noticeably. If that's the case, it's a good bet you have a leak somewhere in your brake system -- which means that you likely have bigger brake issues than something as simple as worn brake pads. C. Other major problems And other problems include the brake fluid vaporization and brake fluid freezing though vaporization occurs only in rare cases. Freezing is quite common in colder places like Scandinavian countries and Russia etc. where the temperature reaches as low as -50°C to−65°C, in such cases there is a need for some anti-freezing agents and increases the complexity and cost of the system.

Working Principle A. Electromagnetism Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation. Electromagnetism(refer fig-1) is the force that causes the interaction between electrically charged particles; the areas in which this happens are called electromagnetic fields.

Fig-1 Working principle of Electromagnetism 13

B. Magnetic Effect of Current The term "Magnetic effect of current" means that "a current flowing in a wire produces a magnetic field around it"(refer Fig-2). The magnetic effect of current was discovered by Oersted in 1820. Oersted found that a wire carrying a current was able to deflect a magnetic needle.

Fig-2 Magnetic Field Lines through and around the current carrying solenoid C. Electromagnet An electric current can be used for making temporary magnets known as electromagnets. An electromagnet works on the magnetic effect of current. It has been found that if a soft iron rod called core is placed inside a solenoid, then the strength of the magnetic field becomes very large because the iron ore is magnetized by induction D. Factors affecting strength of an Electromagnet The strength of an electromagnet is:  Directly proportional to the number of turns in the coil.  Directly proportional to the current flowing in the coil.  Inversely proportional to the length of air gap between the poles.

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In general, an electromagnet is often considered better than a permanent magnet because it can produce very strong magnetic fields and its strength can be controlled by varying the number of turns in its coil or by changing the current flowing through the coil. Electromagnetic brakes operate electrically, but transmit torque mechanically. This is why they used to be referred to as electro-mechanical brakes. Over the years, EM brakes became known as electromagnetic, referring to their actuation method. The variety of applications and brake designs has increased dramatically, but the basic operation remains the same. Single face electromagnetic brakes make up approximately 80% of all of the power applied brake applications. It was found that electromagnetic brakes can develop a negative power which represents nearly twice the maximum power output of a typical engine, and at least three times the braking power of an exhaust brake. These performances of electromagnetic brakes make them much more competitive candidate for alternative retardation equipment’s compared with other retarders. The brake linings would last considerably longer before requiring maintenance, and the potentially “brake fade” problem could be avoided. In research conducted by a truck manufacturer, it was proved that the electromagnetic brake assumed 80 percentage of the duty which would otherwise have been demanded of the regular service brake. Furthermore, the electromagnetic brake prevents the dangers that can arise from the prolonged use of brakes beyond their capability to dissipate heat. This is most likely to occur while a vehicle descending a long gradient at high speed.

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COMPONENTS USED 1. AC Motor An AC motor is an electric motor driven by an alternating current. It commonly consists of two basic parts, an outside stationary stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft that is given a torque by the rotating field. Where speed stability is important, some AC motors (such as some past motors) have the stator on the inside and the rotor on the outside to optimize inertia and cooling.

Fig-3 AC Motor

2. IR Sensor Infrared (IR) light leaving an LED reflects off an object. The reflected light travels back to an IR receiver. The IR receiver “detects” the presence of the object. The object does not need to move to be detected. This sensor provides the system with ability to detect the presence of object position. The theory is the IR emitter emits infrared light. If an object presence the signal will be reflected back to the receiver. Then, the IR detector implemented will detect the reflected light. Then, the correspondence signal sends to the Micro Controller for being analyze.

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Fig-4(a) Working Principle

Fig-4(b) Component

3. Capacitor A capacitor is a ive two terminal electrical component used to store electrical energy temporarily in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors (plates) separated by a dielectric (i.e. an insulator that can store energy by becoming polarized). The conductors can be thin films, foils or sintered beads of metal or conductive electrolyte, etc. The non-conducting dielectric acts to increase the capacitor's charge capacity. Materials commonly used as dielectrics include glass, ceramic, plastic film, air, vacuum, paper, mica, and oxide layers. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

Fig-5 100F Capacitor

4. Diode In electronics, a diode is a two terminal electronic component that conducts primarily in one direction (asymmetric conductance) ; It has low (ideally zero) resistance to the flow of current in one direction, and high (ideally infinite) resistance in the other. A semiconductor 17

diode, the most common type today, is a crystalline piece of semiconductor material with a p–n junction connected to two electrical terminals.

Fig-6 Diode

5. Resistors A resistor is a ive two terminal electrical component that implements electrical resistance as a circuit element. Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits. In electronic circuits, resistors are used to limit current flow, to adjust signal levels, bias active elements, and terminate transmission lines among other uses.

Fig-7 Resistors

6. Transformer Transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction Electromagnetic induction produces an electromotive force within a conductor which is exposed to time varying magnetic fields Transformers are used to increase or decrease the alternating voltages in electric power 18

applications varying current in the transformer primary winding creates a varying magnetic flu in the transformer core and a varying field impinging on the transformers secondary winding This varying magnetic field at the secondary winding induces a varying electromotive force E or voltage in the secondary winding due to electromagnetic induction Making use of faradays law discovered in in conduction with high magnetic permeability core properties transformers can be designed to change efficiently C voltages from one voltage level to another within power networks.

Fig-8 Working Principle and the component used 7. Transistor A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.

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Fig-9 7569 Transistor 8. Relay The term Relay generally refers to a device that provides an electrical connection between two or more points in response to the application of a control signal. The most common and widely used type of electrical relay is the electromechanical relay or EMR. The most fundamental control of any equipment is the ability to turn it “ON” and “OFF”. The easiest way to do this is using switches to interrupt the electrical supply. Although switches can be used to control something, they have their disadvantages. The biggest one is that they have to be manually (physically) turned “ON” or “OFF”. Also, they are relatively large, slow and only switch small electrical currents.

Fig-10(a) Working Principle

Fig-10(b) Component

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9. Solenoid A solenoid is a type of electromagnet when the purpose is to generate a controlled magnetic field. If the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

Fig-11 Solenoid Used

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Infrared Sensor An infrared sensor is an electronic device, that emits in order to sense some aspects of the surroundings. An IR sensor can measure the heat of an object as well as detects the motion. These types of sensors measures only infrared radiation, rather than emitting it that is called as a ive IR sensor. Usually in the infrared spectrum, all the objects radiate some form of thermal radiations. These types of radiations are invisible to our eyes, that can be detected by an infrared sensor. The emitter is simply an IR LED (Light Emitting Diode) and the detector is simply an IR photodiode which is sensitive to IR light of the same wavelength as that emitted by the IR LED. When IR light falls on the photodiode, the resistances and these output voltages, change in proportion to the magnitude of the IR light received.

Fig-12 IR Sensor IR Sensor Circuit Diagram and Working Principle An infrared sensor circuit is one of the basic and popular sensor module in an electronic device. This sensor is analogous to human’s visionary senses, which can be used to detect obstacles and it is one of the common applications in real time. This circuit comprises of the following components    

LM358 IC 2 IR transmitter and receiver pair Resistors of the range of kilo ohms. Variable resistors. LED (Light Emitting Diode).

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Fig- 13 IR Sensor Circuit In this project, the transmitter section includes an IR sensor, which transmits continuous IR rays to be received by an IR receiver module. An IR output terminal of the receiver varies depending upon its receiving of IR rays. Since this variation cannot be analyzed as such, therefore this output can be fed to a comparator circuit. Here an operational amplifier (opamp) of LM 339 is used as comparator circuit. When the IR receiver does not receive a signal, the potential at the inverting input goes higher than that non-inverting input of the comparator IC (LM339). Thus, the output of the comparator goes low, but the LED does not glow. When the IR receiver module receives signal to the potential at the inverting input goes low. Thus, the output of the comparator (LM 339) goes high and the LED starts glowing. Resistor R1 (100), R2 (10k) and R3 (330) are used to ensure that minimum 10 mA current es through the IR LED Devices like Photodiode and normal LEDs respectively. Resistor VR2 (preset=5k) is used to adjust the output terminals. Resistor VR1 (preset=10k) is used to set the sensitivity of the circuit Diagram. Read more about IR sensors. Different Types of IR Sensors and Their Applications IR sensors are classified into different types depending on the applications. Some of the typical applications of different types of sensors are The speed sensor is used for synchronizing the speed of multiple motors. The temperature sensor is used for industrial temperature control. PIR sensor is used for automatic door opening system and Ultrasonic sensor are used for distance measurement.

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IR Sensor Applications IR sensors are used in various Sensor based projects and also in various electronic devices which measures the temperature that are discussed in the below. Radiation Thermometers IR sensors are used in radiation thermometers to measure the temperature depend upon the temperature and the material of the object and these thermometers have some of the following features   

Measurement without direct with the object Faster response Easy pattern measurements

Flame Monitors These types of devices are used for detecting the light emitted from the flames and to monitor how the flames are burning. The Light emitted from flames extend from UV to IR region types. PbS, PbSe, Two-color detector, pyro electric detector are some of the commonly employed detector used in flame monitors. Moisture Analyzers Moisture analyzers use wavelengths which are absorbed by the moisture in the IR region. Objects are irradiated with light having these wavelengths(1.1 µm, 1.4 µm, 1.9 µm, and 2.7µm) and also with reference wavelengths. The Lights reflected from the objects depend upon the moisture content and is detected by analyzer to measure moisture (ratio of reflected light at these wavelengths to the reflected light at reference wavelength). In GaAs PIN photodiodes, Pbs photoconductive detectors are employed in moisture analyzer circuits.

Gas Analyzers IR sensors are used in gas analyzers which use absorption characteristics of gases in the IR region. Two types of methods are used to measure the density of gas such as dispersive and non-dispersive. Dispersive: An Emitted light is spectroscopically divided and their absorption characteristics are used to analyze the gas ingredients and the sample quantity. Non-dispersive: It is most commonly used method and it uses absorption characteristics without dividing the emitted light. Non-dispersive types use discrete optical band filters, similar to sunglasses that are used for eye protection to filter out unwanted UV radiation. 24

This type of configuration is commonly referred to as non-dispersive infrared (NDIR) technology. This type of analyzer is used for carbonated drinks, whereas non-dispersive analyzer is used in most of the commercial IR instruments, for an automobile exhaust gas fuel leakages.

Fig-14 Gas Analyzer IR Imaging Devices IR image device is one of the major applications of IR waves, primarily by virtue of its property that is not visible. It is used for thermal imagers, night vision devices, etc. For examples Water, rocks, soil, vegetation, an atmosphere, and human tissue all features emit IR radiation. The Thermal infrared detectors measure these radiations in IR range and map the spatial temperature distributions of the object/area on an image. Thermal imagers usually composed of a Sb (indium antimonite), Gd Hg (mercury-doped germanium), Hg Cd Te (mercury-cium-telluride) sensors. An electronic detector is cooled to low temperatures using liquid helium or liquid nitrogen’s. Then the Cooling the detectors ensures that the radiant energy (photons) recorded by the detectors comes from the terrain and not from the ambient temperature of objects within the scanner itself an IR imaging electronic devices. Thus, this is all about IR sensor circuit with working and applications. These sensors are used in many sensors based electronics projects. We believe that, we might have got a better understanding of this IR sensor and its working principle

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METHODOLOGY 

L-frame: - total 6 flats (4 used in making base and 2 used in uprights).

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Fig-15 L-Section: - L section welded on the frame and is provided for solenoid base.

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Fig - 16 Triangulation Member: -

Fig-17 26

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Axle, Tire and brake drum and belt: - axle ed through tire and brake and then welded onto frame.

Fig-18 Motor: - using length of the belt, the placement of motor is finalized.

Fig-19 Solenoid connected to brake: - connection is made between the solenoid piston and brake lever.

Fig-19 27

DESIGN OPTIMIZATION AND CALCULATIONS Final CAD Model

Fig-20

Calculations For calculating minimum stopping distance, a value of 0.8 is a nominal value for the coefficient of static friction between good tires and a good road surface. Almost always, coefficients of kinetic friction are less, and are dramatically less for wet, icy, slick, sandy, dirty very smooth or oily surfaces. For many newer high performance tires with good tread, the coefficient of kinetic friction on a dry road surface may approach 0.8 if the braking is not so prolonged as to cause tire melting. You may wish to plug in a smaller value such as .7 or .6 for a vehicle with normally driven and worn tires. Poor condition tires might yield .5 or .4 for a closer representation of friction (For eg. In factories where rough roads are absent and tiled floor is present).

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The stopping distance is given by:

Also, since the stopping force for braking is provided entirely by the friction, the maximum force that can be applied for braking (above which the tire will lock and wheel will start to skid) is = μmg The maximum deceleration that can be provided, a = μg Therefore minimum stopping time is given by t=v/a = v/ μg The values for the project:      

RPM of motor, R1 = 9000 rpm Size/diameter of driver pulley, D1 = 2.5cm Size/diameter of driven pulley, D2 = 17”= 17x2.54cm = 43.18cm Reduction Ratio, S = D1/D2 = 2.5/43.18 = 1:17.272 RPM of tire, R2 = S x R1 = 9000/17.272 = 521.075rpm Speed of tire, V = R2 x 0.022609048 = 11.78 m/s

Therefore, Stopping Distance, d1 = 11.782/ (2 x 0.4 x 9.81) = 17.682 m However, on rough road Stopping Distance, d2 = 11.782/ (2 x 0.7 x 9.81) = 10.104 m Stopping time, t1 = 11.78/ (.4 x 9.81) = 3.002sec Stopping time, t2 = 11.78/ (0.7 x 9.81) = 1.71sec

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ADVANTAGES AND DISADVANTAGES Advantages: 1) Problems of drum distortion at widely varying temperatures. Which is common for friction-brake drums to exceed 500 °C surface temperatures when subject to heavy braking demands, and at temperatures of this order, a reduction in the coefficient of friction (“brake fade”) suddenly occurs. 2) This is reduced significantly in electromagnetic disk brake systems. 3) Potential hazard of tire deterioration and bursts due to friction is eliminated. 4) There is no need to change brake oils regularly. 5) There is no oil leakage. 6) The practical location of the retarder within the vehicle prevents the direct impingement of air on the retarder Caused by the motion of the vehicle. 7) The retarders help to extend the life span of the regular brakes and keep the regular brakes cool for emergency situation. 8) The electromagnetic brakes have excellent heat dissipation efficiency owing to the high temperature of the surface of the disc which is being cooled. 9) Due to its special mounting location and heat dissipation mechanism, electromagnetic brakes have better thermal dynamic performance than regular friction brakes. 10) Burnishing is the wearing or mating of opposing surfaces .This is reduced significantly here. 11) In the future, there may be shortage of crude oil; hence by-products such as brake oils will be in much demand. EMBs will overcome this problem. 12) Electromagnetic brake systems will reduce maintenance cost. 13) The problem of brake fluid vaporization and freezing is eliminated. 14) Electric actuation, no fluid. 15) Easier integration with anti-lock, traction, and dynamic stability controls. 16) Easy individual wheel braking control.

Disadvantages: 1) Dependence on battery power to energize the brake system drains down the battery much faster. 2) Due to residual magnetism present in electromagnets, the brake shoe takes time to come back to its original position. 3) The installation of an electromagnetic brake is very difficult if there is not enough space between the gearbox and the rear axle.

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FUTURE SCOPE 1. CONVEYOR BELT A conveyor moving a series of open boxes under a filling head will use a brake to stop and hold the box stationary while the filling operation takes place. In this application the critical performance characteristics are the ability to repeatedly stop the load in the correct position hundreds or thousands of times per day. 2. PRINTING PRESS In a printing press a roll or paper unwinds into the printing operation. If the speed of the press changes during operation, it is critical that the unwind roll match this change to avoid spilling paper loosely onto the floor. The brake engages at less than full strength to slow the roll but not loo stop it. In this case the brake slips during engagement. 3. MILLING MACHINE In a milling machine the vertical axis is typically driven into position by a lead screw. Once in position it is critical that the load stay put. A brake is used to simply hold the screw from rotating and moving. Nearly all applications fall within one of these three categories. 4. ROBOTICS Electromagnetic brake can position and hold robotic equipment. Hence, emergency braking in the event of power loss can prevent damage 10 equipment. 5. MEDICAL EQUIPMENT Electromagnetic brake is used as parking brakes in wheelchairs and holding brakes in medical apparatus such as mammography & CT scan equipment.

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CONCLUSION 

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In electromagnetic braking system as four disc plates, coils and firing circuits are attached individually on each wheel, even any coil fails the brake does not completely fails remaining three coil works properly. It is found that electromagnetic brakes make up approximately 80% of all of the power applied brake applications. This enhanced braking system not only helps in effective braking but also helps in avoiding the accidents and reducing the frequency of accidents to a minimum. Furthermore, the electromagnetic brakes prevent the danger that can arise from the prolonged use of brake beyond their capability to dissipate heat. These electromagnetic brakes can be used as an auxiliary braking system along with the friction braking system to avoid overheating and brake failure. ABS usage can be neglected by simply using a micro controlled electromagnetic disk brake system. These electromagnetic brakes can be used in wet conditions which eliminate the antiskidding equipment, and cost of these brake are cheaper than the other types. Hence the braking force produced in this is less than the disc brakes.

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References 1. Stephen Z. Oldakowski, Bedford, Ohio(2002): 2. 3. 4. 5. 6. 7. 8.

http://www.ijirst.org/articles/ohio-865523er_9.html Karl Erny, Holzhausem(1999): http://exploredoc.com/doc/9111863/23.jahrgang--nr.-42-vom-14.10.1999.html Hung-Chi Wu, 958-2, Ghung Shan Rd., Tao-Yuan, Taiwan(2007): http://www.dois.moea.gov.tw/content/pdf/moeaic_book_2002~2007.html Jae-Woong Lee, Seoul, Rep. of Korea(2003): http://asia.nd.edu/assets/131479/program_final_white.html Albert E. Miller, Dayton, Ohio(2001): https://billiongraves.com/grave/Albert-EMiller/13448195.html www.wikipedia.com https://www.elprocus.com/infrared-ir-sensor-circuit-and-working/ http://education.rec.ri.cmu.edu/content/electronics/boe/ir_sensor/1.html

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