Patent ID: 8552688
Filing Date: 2013-10-08
Classification: B60L,B60W,F02D,F02N,G01R,Y02T

Abstract:
1. A battery condition estimation device capable of estimating conditions of an on-vehicle battery mounted to a vehicle during an operation period of an internal combustion engine counted from a restart operation of the internal combustion engine to a stop operation of the internal combustion engine, the on-vehicle battery being an electric power supply source to supply an electric power to on-vehicle devices such as an engine starter to start an internal combustion engine, comprising: pre-start operation voltage drop estimation means capable of estimating a battery voltage drop amount, as a pre-start operation voltage drop amount of the on-vehicle battery, based on at least one of detection values regarding battery condition, during a period from initiation of the stop operation of the internal combustion engine until initiation of the restart operation of the internal combustion engine; start operation voltage drop estimation means capable of estimating a battery voltage drop amount, as a start operation voltage drop amount, based on at least one of the detection values regarding the battery condition, during a period from the initiation of the restart operation until completion of the restart operation of the internal combustion engine; and minimum voltage estimation means capable of estimating a minimum voltage of the on-vehicle battery during a period from the initiation of the stop operation of the internal combustion engine until the completion of the restart operation of the internal combustion engine based on a voltage value of the on-vehicle battery detected before the initiation of the stop operation of the internal combustion engine, the pre-start voltage drop amount of the on-vehicle battery estimated by the pre-start operation voltage drop estimation means, and the start operation voltage drop amount estimated by the start operation voltage drop estimation means, wherein the pre-start operation voltage drop estimation means comprises pre-stop operation voltage drop estimation means capable of estimating a battery voltage drop amount of the on-vehicle battery, as a pre-stop operation voltage drop amount, during a period from the initiation of the stop operation until the completion of the stop operation of the internal combustion engine based on at least one of the detection values regarding the battery condition, the battery condition estimation device further comprises an internal resistance value map which stores a relationship between a current value or a voltage value and an internal resistance value of the on-vehicle battery in a one to one correspondence, wherein the pre-stop operation voltage drop estimation means estimates the pre-stop operation voltage drop amount based on the internal resistance value obtained from the internal resistance value map and a current change amount of the on-vehicle battery detected during the period from the initiation of the stop operation until the completion of the stop operation of the internal combustion engine, and the internal resistance map has: wherein when the output voltage of an AC generator capable of charging the on-vehicle battery is equal to an adjustment voltage, the pre-stop operation voltage drop estimation means estimates the pre-stop operation voltage drop amount of the on-vehicle battery based on the current change amount of the on-vehicle battery detected during the period from the initiation of the stop operation until the completion of the stop operation of the internal combustion engine, and based on the internal resistance value of the on-vehicle battery obtained from the current-internal resistance value map based on the current value of the on-vehicle battery detected before the initiation of the stop operation of the internal combustion engine, and when the output voltage of the AC generator capable of charging the on-vehicle battery is less than the adjustment voltage, the pre-stop operation voltage drop estimation means estimates the pre-stop operation voltage drop amount of the on-vehicle battery based on the current change amount of the on-vehicle battery detected during the period from the initiation of the stop operation until the completion of the stop operation of the internal combustion engine, and based on the internal resistance value of the on-vehicle battery obtained from the voltage-internal resistance value map based on the voltage value of the on-vehicle battery detected before the initiation of the stop operation of the internal combustion engine.