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Originally Posted by rwemersonrw
Hope all is well. I was reviewing this thread and I was just curious: How do I know that I've triggered ABS? I do not feel the "judder" on my brake pedal that some people have described? Does that mean I haven't triggered it? Thanks!
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Depends on the brake system in your car. Some newer cars have by-wire brakes. Means you won't feel the pedal pulsating. C8 is one of those cars for example. But if you see a vacuum booster under the hood you know you're connected and will feel the pedal.
Also no vehicle ABS outperforms threshold braking. Point of ABS is to maintain steerability, not to achieve min stopping distance.
Also this is limited by information available to the brake system. You have to know the exact speed of the car to know how much slip the wheels have. If all 4 wheels are sliding, you no longer know exact speed of the car based on wheel speed sensors. To maintain knowledge of exact speed at any given point brakes are released off of 2 wheels, while the other 2 are slipping. This way you can maintain an accurate reference.
A fine tuned human can maintain ~4-6% slip by gut feel, preventing the need to release brake pressure during the stop on any of the wheels. That's why well executed threshold braking always beats ABS in stopping distance. It is possible to develop ABS that matches or maybe even beats the driver best effort, but it would require additional high resolution, high frequency speed measurement capability which doesn't depend on the wheel speed sensors. And that gets expensive.