Patent ID: 7467692
Filing Date: 2008-12-23
Classification: B60T

Abstract:
1. In a brake system comprising: a piston for applying an output force to a brake; a motor operatively connected to the piston via a gear assembly or other means of transmission; and a controller receiving a brake force request and sending a brake force signal to the motor to cause the motor to move the piston and apply an output force to the brake; a method for performing high force static braking with reduced motor power consumption and self-heating comprising the steps of: generating a changing brake force signal during an initial period during which the brake force request is changing, applying a substantially constant brake force signal during a period when the brake force request is substantially fixed, the output force being less than the brake force signal during this period, due to resisting friction in the gear assembly or transmission, and following the period of applying the substantially constant brake force signal, while the brake force request is still substantially fixed, momentarily increasing the brake force signal to a value greater than the substantially constant brake force signal, sufficient to overcome internal friction of the gear assembly or transmission, and then reducing the brake force signal to a value somewhat less than the substantially constant brake force signal, to achieve and sustain an output force that is now assisted by the friction of the gear assembly or transmission, therefore resulting in an output force that equals or exceeds the substantially constant brake force signal, thereby providing the desired output force at a reduced power level to the motor, and reducing the heat generated inside the motor during the high force static braking.