Method for maximizing microhybrid auto start-stop availability

Patent metadata

Field	Value
Publication number	US-9284896-B2
Application number	US-201313754930-A
Country	US
Kind code	B2
Filing date	Jan 31, 2013
Priority date	Jan 31, 2013
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

A method for maximizing the availability of start-stop operations within a microhybrid vehicle includes determining the electric current drawn by a set of electrical components of the vehicle, from the vehicle's battery. The internal resistance of the vehicle's battery, and the resistance of a starter motor loop circuit coupled to the engine of the vehicle are dynamically calculated. The closed-circuit voltage of the battery is predicted, using the internal resistance of the battery, the resistance of the starter motor loop circuit, and the current drawn by the set of electrical components of the vehicle. The start-stop operation is carried out if the closed-circuit voltage of the battery is predicted to be above a pre-determined minimum value.

First claim

What is claimed is:

1. A method of maximizing usage of start-stop operation for a vehicle equipped with a start-stop system and having an engine, a battery, and electrical components, and further having a battery management module including a processor, the method comprising:
measuring an electric current (I L ) drawn by a set of electrical components of the vehicle, from the battery;
determining an internal resistance of the battery of the vehicle (R B ), employing the battery management module, utilizing inputs from one or more temperature sensors positioned to monitor the battery temperature;
determining a resistance of a starter motor loop circuit (R S ) coupled to the engine and the battery of the vehicle, employing the battery management module, utilizing inputs from one or more temperature sensors positioned to monitor the loop circuit temperature; and
calculating a closed-circuit voltage of the battery of the vehicle (V B ), using the current drawn by the set of electrical component (I L ), the internal resistance of the battery (R B ), and the resistance of the starter motor loop circuit (R S ), employing the processor; and
carrying out the start-stop operation for the engine of the vehicle if the closed-circuit voltage of the battery of the vehicle is predicted to be above a pre-determined value.

2. The method of claim 1 , comprising, using an open-circuit voltage (V OC ) of the battery of the vehicle as a parameter to calculate the closed-circuit voltage (V B ) of the battery.

3. The method of claim 1 , further comprising, measuring the temperature of a coolant for the engine of the vehicle, and the temperature of the air surrounding one or more components of the vehicle constituting the starter motor loop circuit, to determine the resistance of the starter motor loop circuit (R s ).

4. The method of claim 1 , further comprising, continuously determining the internal resistance of the battery (R B ) and the resistance of the starter motor loop circuit (R s ), after an auto-stop condition for the vehicle's engine has occurred, to predict restart conditions for the engine.

5. The method of claim 1 , wherein the pre-determined value for the closed-circuit voltage of the battery is greater than 7 Volts.

6. The method of claim 1 , wherein the pre-determined value for the closed-circuit voltage of the battery depends on the cumulative power required to operate the set of electrical components of the vehicle, when an auto-stop operation for the engine of the vehicle has been initiated.

7. The method of claim 1 , wherein the vehicle is a microhybrid electric vehicle.

Assignees

• Ford Global Tech Llc

Inventors

• Atluru Ravi
• De Biasi Chuck
• Liu Xiangying
• Deljevic Zeljko
• Celinski David
• Symonow David Anthony
• Rademacher Eric Michael
• Pebley Kirk
• Linden Dave W

Classifications

• F02N2200/046

  Energy or power necessary for starting · CPC title

• F02D35/0007 Primary

  using electrical feedback (F02D35/0015 takes precedence) · CPC title

• F02N2200/044

  Starter current · CPC title

• F02N2200/023

  Engine temperature · CPC title

• F02N2200/061

  Battery state of charge [SOC] · CPC title