Engine control device and method for estimating brake pedal depressing force

An engine control device configured to control an engine based on operation of an accelerator pedal and a brake pedal, comprising:

• a master vac negative pressure acquiring unit configured to acquire a master vac negative pressure in a master vac, wherein the master vac includes a stabilized chamber having an internal pressure kept negative, and a variable pressure chamber having an internal pressure which changes in accordance with an actuation of the brake pedal, wherein the master vac amplifies a brake pedal depressing force applied to the brake pedal in accordance with a difference between the internal pressure of the stabilized chamber and the internal pressure of the variable pressure chamber, and wherein the master vac negative pressure is a negative pressure of the stabilized chamber of the master vac;
• a brake working fluid pressure acquiring unit configured to acquire a brake working fluid pressure as a braking hydraulic pressure generated by a master cylinder in accordance with the brake pedal depressing force amplified by the master vac;
• a necessity determining unit configured to determine whether or not it is necessary to decrease engine output based on the master vac negative pressure acquired by the master vac negative pressure acquiring unit and the brake working fluid pressure acquired by the brake working fluid pressure acquiring unit, when both the accelerator pedal and the brake pedal are depressed simultaneously;
• and
• an engine controlling unit configured to perform an output decreasing control to decrease the engine output when the necessity determining unit determines that it is necessary to decrease the engine output.