Robert Bosch has come up with an anti-lock braking system for fast moving hydrostatically driven vehicles, particularly tractors.
Now that top speeds have greatly increased, the aim is to reduce energy losses in brakes and brake wear by using the transmission system to perform braking. However, if applied directly, this can prove too fierce, states Bruno Hartmann, vice president sales for international mobile hydraulics. If not well controlled, this can lead to engine over-speed and skidding in wet conditions. The answer, it seems, is to improve electronic control.
ABS needs to be added, according to Hartmann: “Whenever a wheel locks, the system reduces wheel motor torque.” He describes it as an old idea – regenerative braking – but with new software. Wet condition tests when subjecting a tractor to emergency stops from 40 km/h show that the vehicle is unstable during braking, unless the system is engaged, which restores stability.
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