Я, например, могу помочь лишь подробнейшим описание работы на англ. с пресс-сайта.
ALFAROMEO, 1/20/1999
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ALFA 156: 2.0 SELESPEED
Towards a sportier drive
An Alfa Romeo with a gearbox derived from that of a Ferrari: meet the new Alfa 156 2.0 Selespeed with five-speed gearbox and robotised gear shift.
The Selespeed can be operated either using a two-button control on the steering wheel or a sequential joystick control on the tunnel between the seats. The Selespeed gearbox will allow Alfa 156 customers to discover a new way of driving: sporty, comfortable and safe in all conditions.
Sporty, because it allows fast, crisp shifts for better performance. An engineering feature of current Formula 1 sports cars has been applied to a mass-produced car with exceptional dynamic qualities.
Comfortable, because it is easy to use and less tiring than a conventional gearbox. The clutch pedal has been done away with and the gears are easy to engage. Any detrimental grating or binding has been eliminated and the engine never accidentally stalls.
The Selespeed also ensures smooth shifting and gradual torque transmission to the wheels. When in 'city' mode, it becomes a relaxing automatic transmission, ideal for town traffic.
The Alfa 156 2.0 Selespeed gearbox is also very safe, because the wheel is under full control even during gear shifts (you never have to remove a hand to reach the gear lever). Because the clutch pedal has been taken away, you are held more tightly in your seat on corners because your left leg is free to help.
How does it work and what are its advantages
From an engineering viewpoint, a conventional gearshift involves three stages: during the first stage, the clutch opens to gradually remove torque from the wheels; during the second stage (with zero torque), the driver selects and engages the gear; during the third, the clutch closes to send power back to the wheels (return torque) and the engine revs begin to rise.
The Selespeed gearbox implements these manoeuvres in fully automatic manner. When you change gear, you no longer need to release the accelerator pedal and depress the clutch: the electronic control unit controls the gearbox and requests clutch opening, it reduces torque regardless of the amount by which the accelerator is depressed - and also selects and engages the gears.
The Selespeed is to all intents and purposes a 'robotised' manual gearbox. The decision over which speed to be engaged is left to the driver, but three actuators intervene to carry out the actions that are normally performed during conventional gear shifts: one controls the clutch, the other controls engagement and the third controls speed selection.
A fourth actuator is linked to the engine's electronic throttle. This device manages drive torque flexibly on the basis of requests received through the gearbox control system. During gear shifts, the Selespeed is in charge of the engine: the engine must therefore be in optimum condition to respond with alacrity.
One advantage of the new gearbox is its fast gear engagement. Shift time is measured from the beginning of torque discharge to the end of torque return. With a conventional manual gearbox, this operation takes one to one-and-a-half seconds. The Selespeed takes the same time, when it is driven in normal mode. When the driver opts for a sporty drive (i.e. the accelerator is depressed through more than 60 per cent of its travel and engine speed is maintained at about 5000 rpm), the system shifts gear in half the time: 4-5 tenths of a second - less time than the best test-driver would take using a conventional manual gearbox.
A Selespeed makes it possible to push sportiness to the edge without altering engine performance (on a par with that of the 2.0T.Spark). The driver can shift gears without taking his hands off the steering wheel and without using the clutch. He is therefore left free to concentrate on steering and braking, which are the strong points of an Alfa 156. Without mentioning that the system prevents over-revving because if the driver happens to hesitate, the gear changes automatically.
Sporty when needed then, but also comfortable and easy to drive. The Selespeed can work in two modes: semiautomatic and automatic. In the first case, the driver changes gear manually using a lever on the tunnel or buttons on the steering wheel and the system automatically operates the clutch, selects and engages the gear and governs the engine during shifts. In the second case, when the 'city' button is pressed, shift controls and decisions over the type of gear to be engaged are delegated to the Selespeed and you are left free to enjoy a very relaxed drive that is particularly appreciated when driving through town traffic.
How it is made
The Selespeed gearbox is equipped with a hydraulic power system that constitutes the system's energy source. An electric pump takes oil up from a reservoir and sends it to an actuator that generates pressure in the circuit and provides the energy required to move the engagement and disengagement levers and to select the speeds - and also to operate the clutch.
Because the system needs energy from the time of start-up, the pump begins to turn even before the ignition is turned on - when the driver's door is opened to be exact. The circuit has already reached the required pressure by the time the car sets off.
The fuel supply unit is governed by a dedicated electronic control unit, manufactured by Magneti Marelli, the company responsible for the Ferrari 355 unit. The control unit communicates continuously with the Bosch Motronic unit, which controls the engine and is responsible for processing the driver's requests and converting them to gear commands.
To do this, the control unit calls on information such as accelerator pedal position, car speed, engine rpm and torque input. The system is also supplied with data by sensors and potentiometers located at specific points of various drive components, which it uses to monitor component service status.
Gear shifts can be made using steering wheel controls or a joystick located between the seats, in place of a conventional gear lever.
The steering wheel is fitted with two buttons: an 'up' control on the right hand side (identified by a '+' sign) for sequential gear shifts during acceleration; a down control (identified with a '-' sign) on the left for changing down when the car decelerates.
The lever works in the same way: it is shifted in the direction of motion to change up and towards the back of the car to change down.
A 'city' control on the central tunnel is used to activate automatic mode (the steering wheel or joystick controls are no longer required when this mode is selected). Unlike conventional automatic transmissions, however, this function imposes a single driving style suited to town traffic or routes with heavy traffic with a need for frequent gear shifts.
A display in the rev counter indicates number of the gear engaged, 'city' mode or system faults.
How it is used when driving
An Alfa 156 2.0 Selespeed is easy to drive. To start the car, simply hold the brake pedal down and engage gear to set off: first, second or reverse. Use the joystick on the central console for this operation, because the steering wheel controls are not active when the car sets off.
Now take your foot off the brake and accelerate: the system closes the clutch gradually to give the car pick-up. Once it is travelling at 10 km/h, you can begin to change gear using the steering wheel controls or continue to use the joystick. The joystick takes priority if both controls are operated at the same time.
We have already said that you need not take your foot off the accelerator pedal during gear changes. The Selespeed controls the engine directly to reduce and then increase torque and adjust rpm to the new speed engaged.
Due to an inbuilt maximum safety system, gear shift commands are accepted only if compatible with maximum and minimum rpm limits and may be interrupted at any time by another request. Actuator control sequences are also equipped with a timeout function, which allows the command to be repeated if it is not initially successful. When mechanical binding occurs during gear engagement, the system first attempts to engage the required gear and then, if this is not possible, it immediately moves to a higher gear so as not to leave the car in neutral.
Finally, during emergency braking manoeuvres, the system detects the rate at which engine speed is dropping (rpm levels are directly linked to vehicle deceleration because the clutch is still closed) and automatically changes down through the gears. This operation is carried out only in the case of sudden braking manoeuvres: the system does not replace the driver altogether, but intervenes solely to ensure greater safety.
Different approaches for different situations. On a flat surface, when the driver presses the accelerator to the floor and pushes the car in a low gear until the engine races, the system shifts up a gear by itself. The same thing does not happen, however, if the accelerator pedal is not pressed. In this case, the Selespeed realises that the car is on a downhill gradient and automatically closes the clutch once a set speed has been reached to increase the engine braking effect. Control of the car is restored to the driver when the accelerator is pressed again.
The Selespeed has a nice surprise up its sleeve for seasoned drivers. The new gearbox will double-shift automatically. When you change up, you must increase rpm during gear engagement. The surge of extra gas you provide to achieve this result is perfectly gauged to suit engine speed and rpm at the moment of gear shifting. This is an important safety guarantee. Double-shifting avoids excessive engine rpm increases due to the force of inertia and possible wheel lock during over-run.
This is not all. When you release the accelerator as you approach a cross-roads or traffic light, the Selespeed detects your intention to slow down and automatically shifts down and releases the clutch to prevent the engine stalling. If you intend to start off again without pulling the car up completely, you will find yourself already in the best gear for pulling away. The system automatically engages first gear when you stop the car.
With the car at a standstill, press the brake and push the gear lever to the right to engage neutral. If the accelerator and brake pedals are not touched for one minute, the gearbox automatically shifts to neutral. For safety reasons, you are prevented from engaging neutral at speeds greater than 40 km/h.
A speed must be engaged before you can turn off the engine and remove the ignition key. If you turn the ignition key to 'off' with the gearbox in neutral, a buzzer reminds you of your mistake.
The system deactivates itself two seconds after receiving a zero speed signal from the engine and the gearbox input and output - and also after saving operating and test data in the control unit's permanent memory.
The Selespeed automatically shifts to neutral when the car is restarted.
Safety
As we have seen, the Selespeed boasts a series of features designed to prevent the driver making incorrect commands that could create dangerous situations or damage the system. The system is therefore able to ensure maximum safety in all situations.
Let's take a look at a few of these features:
The engine may be started with a gear engaged or in neutral. In any case, when the brake pedal is pressed and the accelerator pedal released (condition required for start-up), the system automatically searches for neutral.
The brake pedal must be held down in order to engage a gear when the car is at a standstill. This prevents the lever from being operated involuntarily by the passengers or driver.
With the car at a standstill and the engine running, only speeds enabled for take-off are accepted, i.e. first, second and reverse.
When car speed is lower than 10 km/h, the steering wheel buttons are disabled. This prevents possible driver errors during parking manoeuvres.
If two gear shift requests are made simultaneously using the steering wheel buttons and joystick, the joystick command takes priority.
A reverse engagement command is not accepted if the car is moving.
Gear shift requests are not accepted if they would increase or decrease engine rpm to levels outside the permitted range.
The gear is changed automatically when the driver continues to race the engine without changing gear. This does not happen if the accelerator pedal is not pressed to the floor as the system detects a downhill gradient.
Neutral commands are inhibited at speeds greater than 40 km/h to prevent incorrect commands being issued in critical situations (such as descents or overtaking).
The gearbox is shifted to neutral automatically and notifies the driver using a buzzer when:
with the engine running, the driver's door is open and neither accelerator nor brake have been pressed for at least one second (e.g. if, as sometimes occurs, the door is held open during a difficult parking manoeuvre);
with the engine running, a gear is engaged and neither accelerator nor brake are operated within one minute;
oil pressure is too low to operate the clutch.
'City' mode is cancelled when the driver selects a gear directly using joystick or buttons.
You are also kept up to date on system operation and informed when a gear change is impossible. Reverse engagement is indicated by an acoustic and visual signal, for example, and another signal notifies you when you turn off the engine and leave the gearbox in neutral. A warning light also comes on when gear oil pressure is too low and an intermittent sound warns you that you are slipping the clutch.
The Selespeed system is also able to test automatically for faults in its components. When the lever is faulty, it automatically switches to 'city' mode. If the fault is another type, it closes down all functions to a minimum in order to allow the driver to reach the closest service centre in complete safety.
