APOFEOSIS OF ERGONOMICS
Steering wheel, two or three pedals, a pair of steering column switches -
how all this is familiar to every driver.
it wasn’t always and,
what’s most interesting is that the “set” will probably change
in the near future.
Ergonomics is a relatively young science. No wonder: at the dawn of the technical age, it was not up to the convenience of the driver. Driving without a horse was already considered a miracle in itself, and the fact that the lucky owner of a gasoline crew had to light a pilot ignition, twist the “curve starter” to exhaustion, and feverishly go through numerous regulators on the move seemed an inevitable payment for technological progress. But - that’s why he is progressing so as not to stand still. The number of organs needed for management has decreased, they gradually acquired the outlines and locations familiar to us, although they could not do without futuristic delights. However, take a better look at the photographs. Here is the Swiss “Dufot” of 1904 with hand gas and an ignition timing, here is a cockpit with devices on the steering wheel (to better see) of the prototype Neumann-Neander of 1939, and here is something from the “Gia JXG” of 1961 …
Here, for example, the driver holds in his hands, although unusual, but the steering wheel. But the story began with the “oxtail” - a long lever, which, in fact, needed to be turned. Even then, on some “strollers”, the vertical movement of the lever was responsible for acceleration and braking … But the lever - it is the lever: either light, but bulky, or compact, but too heavy and inaccurate for control. With the spread of rudders of the "sheepskin" type, the levers disappeared from the cars, however, as it turned out, not forever.
Servo mechanisms appeared - amplifiers, the steering wheel became lighter, and this made it possible to create a compact lever with acceptable effort and accuracy. The experiments were carried out in the USA in the late sixties; they proved the convenience and prospects of the steering lever (by the way, which retained power over gas and brake). However, an unsolvable problem was revealed at that time. Imagine what happens during a sharp turn at high speed … Therefore, the freedom of the driver, depending on traffic conditions, needs to be limited. And the conditions are diverse, you can not do without many sensors and a device that interprets signals. Computers at that time were very cumbersome - at the experienced Ford, the brains occupied the entire trunk and part of the passenger compartment, and yet the controls were not very reliable. The story retained only the idea and words of one of the testers: "An unforgettable feeling - I slightly turned the lever and put in a dizzying bend at a speed of 45 miles per hour."
A couple of decades passed before suitable processors appeared; they took control of the braking and slipping, engine and gearbox. And the lever again revived. Now it resembles a joystick of electronic games, but the functions are the same - direction, gas and brake.
Today, the joystick was in the place of the steering wheel in the experimental Mercedes-Benz-SL500 (see photo). More precisely, there are two of them - under the left and right hand. You never know what someone will like. There are three buttons at the end of the lever (one is not visible), but these are not trigger switches for shooting the remaining participants in the movement, but just switches for direction indicators and an audible signal. Above the ignition, there are four more automatic transmission control buttons with the familiar notation “P”, “D”, “R”, “N”. And no pedals.
Let’s take the driver’s seat, turn the ignition key and press “D”. The motor purred rather, but the car stood, held by the parking brake. However, it is also automatic, and therefore we will not puzzle over in search of the necessary lever - just … put the right (or left) hand on the joystick and push it forward. It’s good that there is no one in front, because it is not clear in what position the wheels were. Well, yes, now it’s clear, in a direct one - our “Merc”, picking up speed, moved forward. Now let's try to “steer” by moving the lever to the right and left. The car obediently writes out an intricate curve, trying to guess our intentions. How to stop? How about a horse - pull the reins, pah, pull the joystick back!
Interestingly, the lever moves sideways by 20 °, and does not move back and forth. However, the gas and brake are obedient to the driver, because the sensor measures not the movement, but the force applied to the joystick. By the way, the amount of effort is also used for turns - it turned out to be more convenient. In the first samples of the system from Fokker Control Systems, the side stick (this is the term for developers) moved in all directions - because of this, the driver lost the feeling of control over the car. Now they control only the movement of the hand. Moreover, with the help of servomotors, feedback with the driver is simulated, that is, the hand feels resistance that increases in proportion to the speed of the machine or, for example, when the wheel runs over a curbstone. Without such a connection, “driving” a real car would have nothing to do, and this is precisely the difference between the side stick and the handle of a game console.
So that the hand does not become numb, all the while putting pressure on the lever, an automatic tempomat is applied here: once you release the handle, it will turn on and maintain the gained speed. So on the highway, the hand just rests on the joystick.
Another thing is parking, especially in reverse. Here, the accumulated experience only interferes. After all, you need to look back, push the joystick forward and, moreover, in the right direction. Well, at least the radar helps - it whistles when it is dangerously close to an obstacle. They say that to acquire the necessary automatism, it may take up to seven years of practice! Just in case, the designers put in the computer program a control function that allows you to ignore the driver’s commands that are ridiculous in this maneuver. So at full speed too steep turn you can not lay!
Well, what did the experiment show? Two groups of novice 17-year-old drivers spent two hours driving and a side stick on the simulator. Then they were offered to make test trips (again on the simulator - such a Mercedes is too expensive a toy). It turned out that in both groups the skills were acquired equally quickly, but in a car with a traditional steering wheel, a quarter of the subjects reacted too slowly to a dangerous situation and in reality would not have avoided a collision. While with the joystick everyone managed to dodge.
What are the advantages of the system developers see? First of all, safety and … safety again. Firstly, as already mentioned, now the computer has got “access” to all the driver’s commands and can actively intervene in case of dangerous orders. Secondly, the absence of a steering wheel allows you to place a large airbag and generally saves the chest from dangerous injuries. Finally, if transferring a foot from gas to brake takes at least 0.2 s (and this is about 5.5 m of braking distance), then everything happens almost instantly (remember: the joystick does not even move back and forth).
Well, what about reliability? Reasonable question. The answer is given by the photo: to the right of the driver in front of the "passenger" … a standard steering wheel and two pedals. So, just in case. However, this, of course, is only on a super-expensive prototype. However, there are similar solutions cheaper - in cars for the disabled. So, the German company "Rollie Cars" from Polkh since 1996 converted 100 joysticks "Windstar" and 15 "Chrysler-voyager" under the joystick. And such a machine costs about $ 100, 000 plus $ 3, 000 for training. Expensive, but comparable to luxury cars.