ESP Does Not Mean Your Car Is Psychic… At Least Not Yet
In the last 10 or so years, ESP has become almost as standard in new cars as seatbelts. OK, the manufacturers may not call this feature ESP, which stands for Electronic Stability Program(me) (the preferred term for Audi and a few others). It could also be called Electronic Stability Control (ESC – the original term used by Mercedes Benz and BMW) or some fancy marque-exclusive name like “Advance Trak” (Ford) or Porsche Stability Management (guess which marque uses that one!). ESC is the most common abbreviation but ESP has a tendency to stick in the mind a bit more, what with the mental images of psychic cars. Or maybe this only sticks in my mind because I’m weird.
Right, no matter what you call it, ESP or ESC is designed to prevent those hairy situations that happen during understeering or oversteering. For those of you who aren’t sure what this means, understeering happens when you don’t get enough turn when going out of the corner and fly off the side of the road, like a stone flying out of David’s sling while the sling itself (the road) keeps curving around. Oversteer is the reverse, when you end up turning more sharply than you ought to and end up on the road on the other side. This happens through driver error while we’re going through the learning process but it can happen to experienced drivers as well when the road is slippery.
This is where ESC or ESP kicks in. During understeer that isn’t caused by driver inexperience, the front wheels start sliding rather than rolling. During oversteer, the rear wheels are the ones doing the sliding. ESP detects that a wheel isn’t spinning all of a sudden when it ought to be but is sliding and skidding. This is done with yaw control. Yaw is a lovely old nautical term that’s been used for several centuries to describe how things swing and sway around a centre point, along with its siblings pitch and roll. You can visualise these easily by holding out your hand flat with the palm down and your thumb and pinkie pointing out so it looks like a plane. If you wiggle you hand from side to side so the tips of your fingers stay level with your wrist and your thumb and pinkie stay level, that’s yaw. Flip your hand over so it goes palm up, then back again and you’ve got roll. Tip your hand up and down like you’re doing a snake-arms wave dance move, and you’ve got pitch. With me so far? Well, the yaw detector feels how the car is yawing and matches this to what the steering system is doing. If there’s a mismatch, the rest of the system kicks in. It works alongside the traction control, which compares how fast the wheels are turning with how fast the engine is going (a mismatch means slipping (spinning too fast) or skidding (not spinning fast enough)).
ESP always works in tandem with ABS (anti-braking skid) brakes. This is because the main way to stop a skid is to reduce the speed, which your ESP system may do by overriding what your right foot is doing and controlling the throttle to take the power down, and by braking. However, as most of us experienced when we were learning to drive, if you slam the brakes on when you’re travelling at speed, you skid. What we had to do when learning old-school style without any driver aids was to pump the brakes so they didn’t lock up and skid. ABS brakes, however, spare us all the tap-dancing, as they’re able to pump the brakes much faster than we can, even if we’re part of a Riverdance line. A really good ESP system will apply the ABS brakes to as many wheels as it needs to (one, two, three or four) to get the speed down and get the “what ought to happen” and the “what is happening” in the yaw and traction departments happening.
ESC has been proven to reduce accidents on wet, slippery or icy roads. However, like any other driver aid or active safety feature, it’s not a substitute for common sense and driving to the conditions. No matter how good the ESP package is, it can’t suspend the laws of angular momentum. It also won’t do anything about understeer or oversteer caused by driver error when an inexperienced driver turns the steering wheel too little, too much, too soon or too late, as these won’t cause the mismatch that triggers the system. Although it’s called ESP, it can’t actually read your mind as to where you want to go.
At least cars can’t read your mind and work out where you want to go quite yet. Inventors and other clever-clogs are working on it, however. In China at the end of last year (2015), some researchers at Nankai University, came up with a brainwave – or, more accurately, a brainwave detector. This consists of a headset that contains EEG sensors that read the electrical pulses given off by different thoughts, which are then transferred to the steering and braking systems. According to a press release and a video, the team has managed to rig this up to what looks like a standard Haval H9, and the “driver” can make the car go forward, reverse, stop, lock and unlock.
http://www.reuters.com/article/us-china-brainpower-car-idUSKBN0TQ23620151207#FyqvAPiGuj8bgRDV.97
The mind boggles at how this could be combined with Google’s Driverless Car concepts. But hopefully, the mind won’t boggle too much or goodness knows what might happen.
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