Electro-hydraulic braking system having cold temperature detection and compensation

Abstract

An improved cold temperature compensation control method for an EH braking system in which cold temperature operation is detected without requiring a temperature sensor. An electronic controller monitors the pressure developed by one or more electrically operated boost units for a characteristic pressure profile that occurs in cold temperature operation of the braking system, and adjusts the control strategy when the characteristic pressure profile is detected. The characteristic pressure profile is deemed by its frequency and amplitude parameters; specifically, a frequency above a threshold frequency, and an amplitude above a threshold amplitude. In a first mechanization, the controller responds to a detected cold temperature operation by reducing the gain of a closed-loop pressure control, while in a second mechanization, the controller responds by switching from the closed-loop pressure control to a closed-loop position control.

Dependencies are inferred from the claim text.