Brake controller for preventing wheel lock - has reference signal derived from speed of other road wheels to set correct brake pressure for individual wheel

摘要

The servo control prevents wheel lock, and gives faster response to friction coefficient changes between tyre and road surface than earlier designs. It improves performance of the system on icy roads where the road to tyre friction can change very suddenly. The retardation of the wheel being controlled by a sensor and the actual speed by a pulse generator. The speed of other road wheels is similarly measured and applied to a max. value detector. This value and a voltage proportional to impulse generator frequency, are applied to a comparator. Its output is one of two reference values for determining the required alteration in brake pressure, the other being derived from the retardation evaluation circuit. Both are applied to an OR gate as one input to an otherwise conventional brake pressure controller.