PURPOSE: To ensure sufficient brake force while assuming failure of regenerative brake system in a vehicle in which a selection is made between hydraulic brake and regenerative brake based on the operation of brake pedal.
CONSTITUTION: Power to be generated through regenerative brake is determined based on the outputs from a voltage sensor 201 and a current sensor 202 for a battery 1 and a decision is made that an abnormal state has occurred if the error between the actual power and theoretically estimated power of regenerative brake exceeds a predetermined value whereby selecting only hydraulic brake having high response and high brake force. A decision is also made that the regenerative brake system is abnormal if the output from the current sensor 202 has a negative value (discharge state) although regenerative torque is produced or if the output from the current has a positive value (charged state) although regenerative torque is not produced.
AOKI YASUSHI
ASANUMA SHINKICHI
ONO ATSUO
