Bosch announces ESP for motorbikes

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IOL mot pic sep25 Bosch Bike Stability Control 1 . Bosch motorcycle stability control system uses pitch and yaw sensors to help the bike straighten up and fly right.

German electronics giant Bosch has developed what it calls the first motorcycle stability control system, using the biker's existing ABS hardware, inputs from yaw, lean and acceleration sensors and some nifty software to improve the stability of the bike - whether accelerating or braking, while riding straight as well as in corners.

That's a pretty big claim - and this is not a hand-built demo set-up, but a production-ready module that will be available at the end of this year on the 2014 KTM 1190 Adventure and Adventure R models.

And this is how it works:

Wheel sensors measure the rotational speed of the front and rear wheels, and an inertia sensor module computes the vehicle's lean and pitch angles more than 100 times a second. By analysing the sensor data, the difference in speed between front and rear wheels, and other motorcycle-specific parameters such as tyre size, tyre shape, and sensor location, the ABS control unit calculates just how much brake force the tyres can deal with.

Traction control uses the difference between front and rear-wheel speeds to modulate maximum engine torque so that even on variable or slippery road surfaces, the driving force is efficiently transferred to the road and the drive wheel does not lose its grip.

It also uses the pitch sensor to control wheelies, once again by regulating maximum torque. This is not new - both BMW and Kawasaki have it on their litre-class sports machines - but the Bosch system also uses the pitch sensor to modulate the brake pressure, thus preventing 'stoppies' under heavy braking.

IOL mot pic sep25 Bosch Bike Stability Control 2 Blue lines show brake hydraulics leading to pressure module, yellow lines the ABS sensor cables on 2014 KTM 1190 Adventure. .

ELECTRONIC COMBINED BRAKING SYSTEM

Moto Guzzi and Honda have had linked brakes for years, but the Bosch system takes the concept to a whole new level by distributing the maximum brake force between front and rear wheels according to how much weight is on each wheel, the angle of lean and the yaw angle (which is a function of how hard you are turning in).

This has two important functions, the first of which is to prevent the bike standing up and running wide if the rider applies the brakes in mid-corner, by balancing the bike and steering with the brakes, Gran-Prix style.

The second is to detect when the front wheel begins to move sideways, and back off on the brakes, allowing the front tyre to recover its grip and, hopefully, preventing a 'low-side'.

The electronic combined braking function distributes the braking force evenly between front and rear wheel at all times, even when the rider uses only one lever.

This, however, can be a problem, particularly when the rider is deliberately using a rear-wheel slide to scrub off speed and turn the bike in more sharply. It's a technique routinely used by most off-road riders and the reason why ABS systems fitted to dual-purpose machines can be disabled at the handlebars.

IMMUTABLE LAWS

The Bosch Boffins are quick to point out that no stability system can re-write the laws of physics; if you go into a corner way too hot the bike is going to spit you off.

However, they say the system can keep the shiny side up in marginal situations, such as wet or slippery roads, or too-heavy use of throttle or brakes, by doing what the rider should be doing - only a hundred times quicker and more accurately.


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