Control device for vehicle

• US 9,140,227 B2
• Filed: 07/19/2012
• Issued: 09/22/2015
• Est. Priority Date: 09/29/2011
• Status: Active Grant

• Current Assignee: Suzuki Motor Corporation
• Original Assignee: Suzuki Motor Corporation
• Inventors: Bito, Seiji
• Primary Examiner(s): Low, Lindsay
• Assistant Examiner(s): Monahon, Brian P
• Application Number:
  US13/553,241
• Publication Number:
  US 20130085657A1
• Time in Patent Office: 1,160 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A control device for a vehicle including an engine stop and start device includes a battery and a vehicle speed detecting unit and includes a battery current detecting unit, a battery temperature detecting unit, a deceleration state detecting unit, a fuel supply stop unit, an average charging current calculating unit, and an SOC estimating unit. The control device calculates, with the average charging current calculating unit, an average of a battery current in a predetermined time from detection of a stop of fuel supply to an engine in a deceleration state of the vehicle. The control device permits a stop of the engine when an SOC calculated by the SOC estimating unit is larger than a predetermined value.

Claims

1. A control device for a vehicle comprising:

an engine stop and start device configured to perform an automatic stop and a restart of an engine, which is a power source for the vehicle;

a battery configured to supply electric power to the engine stop and start device;

a vehicle speed detecting unit configured to detect speed of the vehicle;

a battery current detecting unit configured to detect an electric current of the battery;

a battery temperature detecting unit configured to detect temperature of the battery;

a deceleration state detecting unit configured to detect a deceleration state of the vehicle;

a fuel supply stop unit configured to stop fuel supply to the engine when the deceleration state detecting unit detects that the vehicle is in the deceleration state;

an average charging current calculating unit configured to calculate an average of a battery current detected by the battery current detecting unit;

an SOC estimating unit configured to estimate an SOC of the battery from an average charging current and calculate an estimated SOC;

a lower limit SOC calculating unit configured to calculate a lower limit SOC with which the restart after the automatic stop of the engine can be carried out at least once;

a discharge current calculating unit configured to calculate a discharge current of the battery during the automatic stop of the engine;

an engine stop time calculating unit configured to calculate an engine stoppable time from the automatic stop to the restart of the engine; and

a battery charging amount calculating unit configured to calculate a charging amount for the battery from a charging current and time from a stop of the fuel supply to the engine in the deceleration state of the vehicle until a stop of the vehicle, wherein;

the control device calculates, with the average charging current calculating unit, an average of a battery current in a predetermined time after detection of a stop of the fuel supply to the engine in the deceleration state of the vehicle and permits a stop of the engine when the SOC calculated by the SOC estimating unit is larger than a predetermined value; and

the engine stop time calculating unit includes;

a first stop time calculating unit configured to calculate an engine stop time from a difference between the estimated SOC and the lower limit SOC and the discharge current; and

a second stop time calculating unit configured to calculate an engine stop time from the charging amount calculated by the battery charging amount calculating unit and the discharge current, and

the control device selects, as the engine stop time, larger one of the engine stop time calculated by the first stop time calculating unit and the engine stop time calculated by the second stop time calculating unit.