Historical of Brake

More than one hundred years ago, a kind of disc brake, which was called spot-type disc brakes was developed by Frederick William Lanchester, a British engineer. However, the American inventor Elmer Ambrose Sperry had designed the earliest disc brake in the 1890s. And during the Second World War, benefited from to the development of the aviation industry, aircraft disc were also used on automobile. That kind of brakes was improved from Sperry's and called clutch-type disc brakes.

Spot-type disc brake improvements can be traced back to the 1950s.Today, this kind of brakes used in automobile today is similar to the one in 1950s. Because of superior water resistance and fade performance, disc brake has become more popular than drum brakes in the United States since 1970s. (Harper, 1998)

A modern spot-type disc brake includes some major components: the rotor or disc, caliper, brake pad assemblies and a hydraulic actuation system. The rotor is firmly fitted on the axle hub. So it will rotate with the automobile wheel. The pair of brake pad assemblies, the main friction component, and the other components has to be pressed against the rotor, in order to provide the friction torque to slow down the rotation speed of the wheel. The hydraulic pistons, with the caliper cover, drive the pad assemblies. All of these components are known as the master cylinder. When the brake pedal is depressed, the hydraulic pressure in the pistons housed inside the caliper will increase. That means the master cylinder transforms the brake pedal's motion to hydraulic pressure, which is attached by brake lines and hoses to the caliper.

The figure about the automotive brake system

The brake pad assemblies consist of a friction material, mounted to a rigid pad. And friction materials are always considered as composite materials. Bergman and Jacko state that more than 25 components of a brake pad are termed the friction material. These can be divided into five types: a matrix, fibres, friction modifiers, mineral fillers, and solid lubricants. (Kinkaid, 2003)

In 1978, After Felske’s experimental work, he believed that the coupled vibration of the disc brake assembly lead to brake squeal. He found that "the greater the coefficient of friction of the rubbing surface, the more the likelihood of squeal". Nishiwaki who was working for the Toyota Motor Corporation, found that brake squeal could be eliminated by improving the rotor (or disc). His group eliminated a lot of cooling fins in the vented brake rotor. And Saad's experimental results in a recent also emphasized the importance of brake pad resonance in squeal. (Kinkaid, 2003)

Rhee, working at Allied-Signal Inc., observed the formation and destruction of friction films on the rotor in a series of dynamometer tests. And then he recorded effects on brake squeal. Rhee reported that brake squeal did not occur from an initial state to a stable state when the coefficient of friction was stable in the temperature range of 100– 300 degrees Celsius. High temperature eliminated squeal. However, this process also severely damaged the rotor and the pads. (Rhee, 1990)

Automotive Brake Noise

The automotive experts always discuss the automotive brake system as the topic because it is one of important parts in a vehicle. And the brake noise is still a main problem in the automotive industry even though we have already taken efforts to reduce the noise. According to our report, firstly this paper gives an introduction of automotive brake noise, and then gives a description of the historical development of reducing automotive brake noise, and the vibration of the brake system. After that, we will discuss about the reasons of generating automotive brake noise and give some solutions to reduce the noise. And then, this paper describes the different types of brake noises separately. At last, we will talk something about the developing direction of the automotive brake noise.

The automotive brake noise is generally caused by vibration on several parts within the wheels end section of the vehicle, which is between the tires and the connection to the chassis. The vibration can be generated in some components from the wheel bearing to the ball joint, and it is not always caused by the brake pad. It is normal to generate some vibrations when the brake system is operating, but frequently these vibrations cannot be heard because the frequency and the intensity are low. It only can be heard when the frequency and the intensity of vibration increase to the range.

Some ampliative effects from the overlap of the impulse frequencies and the resonance frequency between some brake system components generate high noise intensity. In other words, when two or more vibrations happen at the same time, or a vibration increases, and exert to the brake disc, the brake rotor is regarded as a speaker to make the vibration can be heard and expand the noise.

At the present time, the technology of producing automotive brake system is developed enough to make the vibration frequency of the brake system low enough that cannot be heard. So the brake noise that can be heard indicates that there are some problems or something wrong with the automotive brake system. As the developing of the automotive industry, automotive experts are doing their best to reduce the noise from brake system. And then, they put forward some methods to eliminate the brake noise. At first, they tried to change the structure of the brake system. Finally, they indicated that improving the situation about wear and tear during the using process. Unfortunately, the technology in those years was not developed enough to support the tests and research about the wear and tear of the brake system.

However, in modern automotive industry, the technology is more developed, and actually, the problems about wear and tear that cannot be solved in the past decades are resolved. Moreover, automotive experts could do much more tests and research to find more methods to reduce the brake noise. In the future, we believe that the automotive brake noise will not be a problem anymore.

Radiator Signature

Radiator Signature

Engine heat rejection @ peak power w/auto trans.	5400 BTU/min
Ambient temperature	100 F Grade with trailer
Air temperature into radiator	100F  (no heat pick up)
Air temperature out of radiator (fan blast)	194 F  AC fan and radiator will be retained for short term radiator out temperature rise
Coolant temperature into radiator (top tank)	245 F  Grade with trailer
Coolant temperature out of radiator (bottom tank)	223 F
Radiator type	Cross flow, tube and spacer, brazed
Radiator dimensions and aspect ratio	28’’w x 20’’h core x 0.80 deep. AR=28/20=1.4
Radiator frontal area	3.9 ft2
Fins per inch and spacer height	21 FPI, louvered, 0.340’’ spacer height
Material	Al, tubes, fins & tube sheets, 50% glass filled nylon tanks
Required front end air flow	280 lbs/min into radiator=3889 ft3/min
Air velocity across radiator	1029 ft/min
Radiator effectiveness	65% based on air side
LMTD, log mean temperature difference	82 F (assume cross flow air and coolant)
Pump coolant flow @ 4320 pump RPM	325 lbs/min
Coolant velocity through individual tubes	6.1 ft/sec
Uo overall heat transfer coefficient	35BTU/F
Inside heat transfer coefficient	1231 BTU/F
Outside heat transfer coefficient	44 BTU/F
Air side pressure drop	0.65’’ water

Prius

Introduction

The Toyota Prius c (Fig.1) is a full hybrid gasoline-electric hatchback designed and manufactured by Toyota Motor Corporation. It was introduced in 2012 after great success of the conventional Toyota Prius. According to the United States Environmental Protection Agency (EPA), Toyota Prius c is ranked by the EPA as the most fuel-efficient vehicle on the road in 2013 excluding plug-in hybrid vehicles and pure electric vehicles [1]. This report provides a brief overview of the most important design features of Toyota Prius c and a brief summary of the riding experience I had during the HEV Powertrain class in November 19, 2013





Toyota Hybrid Synergy Drive (HSD) and Test Drive

Similar to the third-generation conventional Toyota Prius, Toyota Prius c is equipped with HSD system but with a smaller Atkinson-cycle engine and more compact Permanent Magnet Synchronous Motor (PMSM)/generator power split device assembly. With smaller curb weight as well as smaller internal combustion engine, the fuel efficiency is extraordinary even compared to the conventional Toyota Prius.



At the heart of Toyota Prius c is the Toyota Hybrid Synergy Drive computer which oversees operations of the entire mechanical and electronic systems of the vehicle. Toyota Hybrid Synergy Drive computer determines which engine/motor/generator should be running at what conditions. Depending on the driving conditions both the engine and motors can be used to power the vehicle. The following section gives details regarding all the driving modes I have experienced during last Tuesday’s test drive.



1. At start off and low speeds of Prius c, HSD runs the car only on electric motor(s) since the internal combustion is not capable of delivering high fuel efficiency at low speeds.

2. During normal driving, the vehicle is powered mainly by the gasoline engine. Part of the power is distributed to the generator MG1 to recharge the battery.

3. During full acceleration, such as climbing a hill or overtaking a car, both the gasoline engine and the electric motor MG2 power the vehicle.

4. During deceleration, such as when braking, the vehicle regenerates kinetic energy from the front wheels through MG2 (acting as an electric generator) to produce electricity that recharges the battery pack.



5. When the vehicle is stopped, the engine might be turned on to recharge the battery if the battery level is considered to be very low (i.e. stationary charging mode).




ZENN Electric Vehicle (EV)

In addition to the Toyota Prius c, the CHARGE also uses pure EV to conduct research and experiments. ZENN, which stands for zero emission and no noise, is a two-seat pure EV designed and built by ZENN Motor Company to satisfy people’s need for small and neighborhood-only vehicles that do not require full certification as conventional automobiles.



ZENN is equipped with a 30-hp permanent magnet synchronous motor and six 12 Volts sealed lead-acid batteries. Among all six batteries, four of them are placed at the back of the vehicle, and two are placed close to the electric motor under the “engine hood”. In this way, the weight of the entire vehicle can be evenly distributed, which improves a variety of vehicle characteristics including handling, acceleration and traction. ZENN has a maximum speed of 40 Km/h, and its maximum range before requiring a recharge is about 65 Km.



Conclusion



There is no doubt that automotive manufactures are going to pay more attention to the development of HEVs and EVs. Although both HEVs and EVs are feasible solutions to the environmental problems and high oil prices, unless there is a breakthrough in battery technology to allow people to charge their vehicles more conveniently (e.g. similar to refill their gas tank in a gas station) as well as to allow people to drive at least 500 km with a single charge, EVs will not be widely accepted by the public, and HEVs will continue to dominate the market with no compromise in terms of practicality and fuel-efficiency.

The most popular toy. 2015 Jeep Wrangler.

Pushing the limits of where you can take a sport utility vehicle, the Trail Rated®2015 Jeep® Wrangler is open-air freedom personified. From downtown to the back woods, adventure is yours to discover.






Whatever your style, Wrangler can be configured for your ultimate adventure. With choices like full- or half-framed removable doors44 and hard or soft top roof options17 (or choose the Dual Top Group and get both), it’s clear why Wrangler is the only true 4x4 off-road convertible.


Wrangler comes standard with removable full-framed doors44, featuring rugged aluminum-forged hinges. Power windows and doors are standard on Wrangler Sahara and Rubicon, and available on Sport S. All doors include convenient map pockets with open slots along the lower edges for easy washout.

These feature manual locks and are completely removable for the ultimate in open-air adventure and freedom. Available on Sport S and Unlimited Sport S.




You can match the colour of your hardtop to the body colour of your Wrangler. Featuring larger rear and side windows, this innovative Jeep® Wrangler hardtop is available on Sahara, Unlimited Sahara, Rubicon and Unlimited Rubicon.




The standard Sunrider® Soft Top features large rear windows, and is easy to store and easy to open. With a convenient cable release, you can quickly let the sunshine in. The Jeep® Wrangler soft top is constructed from quiet and watertight 3-ply material and it completely folds down and tucks away when you want an open-air drive.

For top-of-the-line Wrangler air-in-your-hair good looks, opt for the Premium Sunrider Soft Top17. It adds durability and sound dampening for a quieter ride. Plus, a dust blocker helps keep your premium soft top in tip-top shape and always easy to wash.




The Jeep® Wrangler Sport model feature 16-inch steel wheels, while the Wrangler Sport S rides on rugged 17-inch aluminum wheels. Sahara rolls on commanding 18-inch aluminum wheels. Rubicon models are equipped with 17-inch polished aluminum wheels with Mineral Grey painted pockets riding on beefy 32-inch BFGoodrich® tires. 18-inch 7-spoke polished aluminum wheels are also available on the Wrangler Sahara.

The Jeep® Wrangler exterior proudly wears its legendary heritage right down to the classic details. There's the iconic 7-slot grille, exposed door hinges, fold-down windshield44, short front and rear overhangs, and trapezoidal wheel arches. It's a style that reinforces the Jeep® rugged functionality and purpose-designed character.


Now standard across all models is a Torx® Toolkit to make door, hardtop and soft top removal a breeze44. This 3-piece set comes in a Jeep®-branded carrying pouch with durable, laminated instruction cards on how to remove and install the doors and hard/soft tops. So whenever the weather or terrain calls for a change, you're equipped to make the call at a moment's notice.




All Wrangler models feature the 3.6L PentastarTM VVT V6 engine with Best-in-Class 285 horsepower and 260 lb-ft of torque23. Among the unique features of Wrangler's 3.6L Pentastar VVT V6 are an acoustic engine cover to reduce noise, optimized upper intake airflow for more torque, added equal-length downpipes to improve low- and mid-range torque response, and a high-mounted, rear-facing alternator for water fording2.


The available 5-speed automatic transmission offers refined shifting and gear selection, and helps the engine operate in a more efficient RPM range to improve fuel economy. The 6-speed manual transmission is standard on all models.
With its Trail Rated® capability and legendary off-road pedigree, it's even more impressive that the award-winning 3.6L PentastarTM VVT V6 also provides the Jeep® Wrangler with strong fuel economy. You'll notice the fuel numbers look different for all makes of 2015 model year cars and light trucks. The federal government has implemented a new 5-cycle test method to replace the 2-cycle method. It now takes into account air conditioner usage, cold temperature operation, and higher-speed driving with more rapid braking and acceleration for more realistic fuel economy numbers. While the new fuel efficiency ratings are lower, actual fuel consumption has not changed – just the way it is calculated.




This is a 2-speed transfer case that offers part-time 4-wheel-drive capability on Sport and Sahara models for smooth, quiet operation and enhanced reliability with manual operation. The Command-TracTM shift-on-the-fly feature allows you to quickly change between 2WD and 4WD, and the 2.72:1 low range gives you the capability to crawl over rocks.




Available for Unlimited Sport, Unlimited Sahara and Unlimited Rubicon, the Max Tow Package provides an impressive 3.73:1 rear axle ratio, a Class II receiver hitch and a 4-pin connector. When equipped, the Jeep® Wrangler towing capacity reaches up to 1,588 kg (3,500 lb).


All Wrangler models are Trail Rated®, which means they're ready for just about anything out there. Created by Jeep®, the Trail Rated system is a series of gruelling tests designed to prove superior off-road capability in 5 main categories: traction, ground clearance, manoeuvrability, articulation and water fording2. With the Trail Rated designation, you can have complete confidence that Wrangler can handle the most challenging terrain. This is Jeep off-road pedigree at its finest.


Engineered and built for the toughest treks, Wrangler's available heavy-duty suspension incorporates solid axles with locating arms, coil springs, track/stabilizer bars and front steering damper. Tunable monotube shock absorbers are firm at low speeds for improved feel on rocks, while delivering a more relaxed ride at higher speeds.




Off-Road Leadership

Nothing tops Wrangler Rubicon for sheer off-road prowess. Engineered to be the ultimate adventure machine, Rubicon goes where others fear to tread, thanks to its Best-in-Class ground clearance, Best-in-Class approach and departure angles, and Best-in-Class manoeuvrability23.

Rock-Trac Transfer Case

Standard on Rubicon, the legendary Rock-Trac® transfer case features a 4:1 low-range gear ratio for more precision and control and incorporates Tru-Lok®front and rear locking differentials, electronic sway bar disconnect and
Dana® 44 heavy-duty solid front axles.




When the going gets tough, Wrangler makes sure the stopping doesn’t. It's equipped with a 4-Wheel Disc Antilock Brake System (ABS) specially calibrated for off-road 4-wheel-drive conditions.




Skid plates protect the underside of your vehicle from off-road rocks and
on-road debris. Front suspension and drivetrain plates are constructed of
3-mm-thick stamped steel and include an automatic transmission skid bar
(not shown) that protects the transmission oil pan, a transfer case skid plate
and a fuel tank skid plate.

2015 Toyota Tacoma

The 2015 Toyota Tacoma inherits legendary Toyota Truck heritage, helping it to earn it the Best Retained Value Award from Canadian Black Book for 5 consecutive years. With 4x2 and 4x4, Access and DoubleCab, and manual and automatic transmission options, there’s a Tacoma waiting for you to take it for a ride.









4-Cylinder

Tacoma's powerful and efficient 2.7L 16-Valve DOHC4-Cylinder engine generates a sturdy 159 horsepower while cranking out 180 lbs.-ft. of torque — smoothly deployed by Toyota's advanced Variable Valve Timing with Intelligence (VVT-i).

V6 Power

For V6 Models, a 4.0L DOHC Engine offers a burly 236 Horsepower, while pounding out 266 lbs.-ft. of trail-tacklingtorque — kept in check by Toyota's Variable Valve Timing with Intelligence (VVT-i). That’s one more reason that all Tacoma engines boast a Tier2 Bin5 Emissions Rating.


All models feature a Limited Slip Differential that works to maintain the equal distribution of torque between the rear wheels, helping to minimize slippage if one or more tires lose traction.4X4 Access Cab V6 models offer an optional Rear Differential Lock providing maximum low-speedtraction by locking the rear differential, helping to deliver equal torque to each wheel and preventing rear wheel slippage (TRD Offroad Package).

ETCS-i

4x4 Tacoma engines also feature an Electronic Throttle Control System with Intelligence (ETCS-i) which results in the optimal amount of throttle for anysituation-enhancing response, increasing fuel efficiency and reducing maintenance.

Transmission

On V6 models, Tacoma offers a finely tuned 6-speed manual or 5-speed automatic with Overdrive. The automatic transmission employs a Super Electronically Controlled Transmission (Super ECT) that works to help eliminate "gear-hunting" on uphill grades. 4-Cylinder models are equipped with a rapid-fire 5-speed manual, or4-speed automatic with Overdrive.

Towing

Hitch up and hit the road with Tacoma's towing capacity of 3,500 lbs. (1,587 kg). Add the 4X4's SR5 and TRD Offroad Packages (Access Cab V6) and SR5, TRD Sport Packages and Limited (Double Cab models) and increase the load to a whopping 6,500 lbs. (2,948 kg — manual), 6,400 lbs. (2,903 kg — automatic).

Suspension

Up front, Tacoma's reliable Independent Double Wishbone Type Suspension employs Coil Springs, Gas Shocks and a Front Stabilizer Bar to keep turns flat and tight, while in the rear, Leaf Springs and Bias Mounted Gas Shocks provide a responsive, level ride. To help tame tougher terrain, the 4x4 models add available Bilstein® Shocks Front and Rear (TRD Offroad and TRD Sport Packages).

Advanced Control

As part of Toyota's Star Safety™ System, all Tacoma models feature the advanced command delivered by Vehicle Stability Control and Traction Control — helping to handle slippery conditions on- or off-road. 4x4 Access Cab V6 models equipped with the TRD Offroad Package add Active Traction Control.

TRD Offroad Package

For those bored by the beaten path, Tacoma's 4X4 TRD Offroad Package offers a stack of trail-blazing features, including an Upgraded Alternator, Front Skid Plate, and a 400-Watt (120V) Cargo Bed Power Outlet.

Induction Motor

Siemens Induction Motor

There are two induction motors, the left one is made of aluminum, the right one is made of copper. The aluminum one is lighter and cheaper. The copper one is more efficiency, heavy and expensive. As to the induction motor, the magnetic fields from the rotor is created due to the electromagnetic excitation, whereas the magnetic fields are generated by permanent magnet inside the rotor of PMMs.

Measurement and Control Equipment

This is a simulator system of different driving conditions of induction motors. We can receive data and analysis the operation conditions by sending signals of different driving conditions to the induction motor.