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ТОП 10 на сайтеПриготовление дезинфицирующих растворов различной концентрации
Техника нижней прямой подачи мяча.
Франко-прусская война (причины и последствия)
Организация работы процедурного кабинета
Смысловое и механическое запоминание, их место и роль в усвоении знаний
Коммуникативные барьеры и пути их преодоления
Обработка изделий медицинского назначения многократного применения
Образцы текста публицистического стиля
Четыре типа изменения баланса
Задачи с ответами для Всероссийской олимпиады по праву
Мы поможем в написании ваших работ!
ЗНАЕТЕ ЛИ ВЫ?
Влияние общества на человека
Приготовление дезинфицирующих растворов различной концентрации
Практические работы по географии для 6 класса
Организация работы процедурного кабинета
Изменения в неживой природе осенью
Уборка процедурного кабинета
Сольфеджио. Все правила по сольфеджио
Балочные системы. Определение реакций опор и моментов защемления
Active Words and Word – Combinations
backlash — скольжение (винта)
ball bearings — шарикоподшипники
bump — бугор, выпуклость
to deviate — отклоняться
feedback — обратная связь, отдача
to intersect — пересекать
kingpin — шкворень
lever arm — плечо рычага
nut — гайка
pitman — соединительная тяга
rack — стойка, рейка
rack-and-pinion — реечная передача
rim — обод, край
robustness — жесткость, прочность
screw — винт
slack — зазор, провес
steering — рулевое управление
steering arm — рулевая сошка
steering wheel — рулевое колесо
tie rod — поперечная рулевая тяга
tight torn — тугой поворот
worm-amd-sector — с червяком и сектором
1. Choose the right word and fill in the gaps:
1. Conventional steering arrangement supposes turning the ... wheels using a hand-operated steering wheel positioned in front of the driver.
2. While a car is turning smoothly, each wheel follows a ... circle,
3. Recirculating ball-and-nut type of steering is practically ... worm-and-sector one.
a) counterpart to
b) the same as
c) much alike
4. The rack is a sort of linear gear which ... with the pinion from side to side.
5. The recirculating ball mechanism ... the considerable friction by placing large ball bearings between the teeth of the worm and those of the screw.
6. The rack-and-pinion’s disadvantage is that it is not adjustable, so when it does ... and develop lash, the only cure is replacement.
7. The driving instructors advice students to keep their thumbs ... the steering wheel.
b) on the front of
c) away from
2. Find in the text equivalents to the following words and word combinations:
Применять термин, передние колеса, допускать, указывать в том же направлении, составлять, рулевая колонка, червячная передача, вращаться вокруг своей оси, износ, замена, первоначально ограниченный, ведущий, в любом направлении, сломать большие пальцы, инструкторы по вождению, при нормальных условиях, новые разработки.
3. Find the English equivalents to the following Russian words:
Divide text into logical parts and give each a suitable title.
Fill in the gaps with the words from the box:
survival reduction mechanical road characteristics
The aim of steer-by-wire technology is to completely do away with as many 1)_______ components as possible. They include the steering shaft, the steering column, gear reduction mechanism and other elements.
Completely replacing 2)_________steering system with steer-by-wire holds several advantages. The absence of steering column simplifies the car interior design. The absence of steering shaft, column and gear 3)_________ mechanism allows much better space 4)_________in the engine compartment. The steering mechanism can be designed and installed as a modular unit. Without mechanical connection between the steering wheel and the 5)___________wheel, it is less likely that the impact of a frontal crash will force the steering wheel to intrude into the driver’s 6)__________space. Steering system 7)_________can easily and infinitely be adjusted to optimize the steering response and feel.
Cruise Control System
By Karim Nice
Cruise control is an invaluable feature on American cars. Without cruise control, long road trips would be more tiring, for the driver at least, and those of us suffering from lead-foot syndrome would probably get a lot more speeding tickets. Cruise control is far more common on American cars than European cars, because the roads in America are generally bigger and straighten, and destinations are farther apart. With traffic continually increasing, basic cruise control is becoming less useful, but instead of becoming obsolete, cruise control systems are adapting to this new reality — soon, cars will be equipped with adaptive cruise control, which will allow your car to follow the car in front of it while continually adjusting speed to maintain a safe distance.
What It Does? The cruise control system actually has a lot of functions other than controlling the speed of your car. For instance, the cruise control can accelerate or decelerate the car by 1 mph with the tap of a button. Hit the button five times to go 5 mph faster.
There are also several important safety features — the cruise control will disengage as soon as you hit the brake pedal, and it won’t engage at speeds less than 25 mph (40 kph). The system has five buttons: On, Off, Set/Accel, Resume and Coast. It also has a sixth control — the brake pedal, and if your car has a manual transmission the clutch pedal is also hooked up to the cruise control.
The on and off buttons don’t actually do much. Hitting the ‘on’ button does not do anything except telling the car that you might be hitting another button soon. The off button turns the cruise control off even if it is engaged. Some cruise controls don’t have these buttons; instead, they turn off when the driver hits the brakes, and turn on when the driver hits the set button.
The set/accel button tells the car to maintain the speed you are currently driving. If you bit the set button at 45 mph, the car will maintain your speed at 45 mph. Holding down the set/accel button will make the car accelerate; and on this car, tapping it once will make the car go 1 mph faster.
If you recently disengaged the cruise control by hitting the brake pedal, hitting the resume button will command the car to accelerate back to the most recent speed setting.
Holding down the coast button will cause the car to decelerate, just as if you took your foot completely off the gas. On this car, tapping the coast button once will cause the car to slow down by 1 mph.
The brake pedal and clutch pedal each have a switch that disengages the cruise control as soon as the pedal is pressed, so you can shut off the cruise control with a light tap on the brake or clutch.
How It’s Hooked Up. The cruise control system controls the speed of your car the same way you do — by adjusting the throttle position. But cruise control actuates the throttle valve by a cable connected to an actuator, instead of pressing a pedal. The throttle valve controls the power and speed of the engine by limiting how much air the engine takes in. Two cables connected to a pivot that moves the throttle valve. One cable comes from the accelerator pedal, and one from the actuator.
When the cruise control is engaged, the actuator moves the cable connected to the pivot, which adjusts the throttle; but it also pulls on the cable that is connected to the gas pedal - this is why your pedal moves up and down when the cruise control is engaged.
Many cars use actuators powered by engine vacuum to open and close the throttle. These systems use a small, electronically-controlled valve to regulate the vacuum in a diaphragm. This works in a similar way to the brake booster, which provides power to your brake system.
Controlling the Cruise Control. The brain of a cruise control system is a small computer that is normally found under the hood or behind the dashboard. It is connected to the throttle control, as well as several sensors. The diagram below shows the inputs and outputs of a typical cruise control system. A good cruise control system accelerates aggressively to the desired speed without overshooting, and then maintains that speed with little deviation no matter how much weight is in the car, or how steep the hill you drive up. Controlling the speed of a car is a classic application of control system theory. The cruise control system controls the speed of the car by adjusting the throttle position, so it needs sensors to tell it the speed and throttle position. It also needs to monitor the controls so it can tell what the desired speed is and when to disengage. The most important input is the speed signal; the cruise control system does a lot with this signal. First, let’s start with one of the most basic control systems you could have — a proportional control.
Proportional Control. In a proportional control system, the cruise control adjusts the throttle proportional to the error, the error being the difference between the desired speed and the actual speed. So, if the cruise control is set at 60 mph and the car is going 50 mph, the throttle position will be open quite far. When the car is going 55 mph, the throttle position opening will be only half of what it was before. The result is that the closer the car gets to the desired speed, the slower it accelerates. Also, if you were on a steep enough hill, the car might not accelerate at all.
PID Control. Most cruise control systems use a control scheme called PID control. Don’t worry, you don’t need to know any calculus to make it through this explanation — just remember that:
-The integral of speed is distance.
-The derivative of speed is acceleration.
A PID control system uses these three factors — proportional, integral and derivative, calculating each individually and adding them to get the throttle position.
We’ve already discussed the proportional factor. The integral factor is based on the time integral of the vehicle speed error. Translation: the difference between the distance your car actually travelled and the distance it would have travelled if it were going at the desired speed, calculated over a set period of time. This factor helps the car deal with hills, and also helps it settle into the correct speed and stay there. Det’s say your car starts to go up a hill and slows down. The proportional control increases the throttle a little, but you may still slow down. After a little while, the integral control will start to increase the throttle, opening it more and more, because the longer the car maintains a speed slower than the desired speed, the larger the distance error gets.
Now let’s add in the final factor, the derivative. Remember that the derivative of speed is acceleration. This factor helps the cruise control respond quickly to changes, such as hills. If the car starts to slow down, the cruise control can see this acceleration (slowing down and speeding up are both acceleration) before the speed can actually change much, and respond by increasing the throttle position.
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