Method and system for controlling electric water pump

Abstract

A method of controlling an EWP through an EWP controller configured to communicate with an engine electronic control unit (ECU) on a controller area network (CAN) includes receiving a CAN signal from the ECU to control the EWP through the CAN; receiving a fail-safe digital signal (FSDS) that is related to a fail-safe control function of an engine or the EWP from the ECU; and controlling the EWP based on the CAN signal and the fail-safe digital signal.

What is claimed is: 
     
         1 . A method of controlling an electric water pump (EWP) through an EWP controller configured to communicate with an engine electronic control unit (ECU) on a controller area network (CAN), the method comprising:
 receiving a CAN signal from the ECU to control the EWP through the CAN;   receiving a fail-safe digital signal (FSDS) that is related to a fail-safe control function of an engine or the EWP from the ECU; and   controlling the EWP based on the CAN signal and the fail-safe digital signal.   
     
     
         2 . The method of  claim 1 , wherein the EWP comprises:
 an auxiliary EWP which cools a heater, a turbocharger, and an inverter.   
     
     
         3 . The method of  claim 1 , further comprising:
 detecting battery power that is supplied to the EWP by a battery or ignition (IG) power that is supplied to the EWP by an IG power portion.   
     
     
         4 . The method of  claim 3 , further comprising:
 receiving a rotation speed command for the EWP from the ECU through the CAN.   
     
     
         5 . The method of  claim 4 , further comprising:
 when the IG power is turned on and the CAN signal is normal, controlling the EWP in a normal mode based on commands from the ECU.   
     
     
         6 . The method of  claim 4 , further comprising:
 when the IG power is turned on and the FSDS is normally inputted to the EWP controller while the CAN signal is not inputted to the EWP controller, controlling the EWP in a limp-home mode.   
     
     
         7 . The method of  claim 4 , further comprising:
 when the IG power is turned on and the FSDS is not normally inputted to the EWP controller while the CAN signal is not inputted to the EWP controller, controlling the EWP in a wake-up mode.   
     
     
         8 . The method of  claim 4 , further comprising:
 when the IG power is turned off and the CAN signal is normally inputted to the EWP controller, controlling the EWP in a normal mode based on commands from the ECU, and   when the IG power is turned off and the CAN signal is not normally inputted to the EWP controller, setting the EWP to enter a sleep mode.   
     
     
         9 . The method of  claim 8 , further comprising:
 when the EWP is set to enter the sleep mode from the normal mode, performing the sleep mode after a predetermined time has passed.   
     
     
         10 . A system for controlling an electric water pump (EWP), comprising:
 an engine electronic control unit (ECU) configured to control an engine;   an electric water pump (EWP) configured to cool the engine;   a battery configured to supply the EWP with battery power;   an ignition power portion configured to supply the EWP with ignition (IG) power; and   an EWP controller configured to communicate with the ECU on a controller area network (CAN), receive a CAN signal from the ECU to control the EWP through the CAN, receive a fail-safe digital signal (FSDS) from the ECU, and control the EWP based on the CAN signal and the FSDS.   
     
     
         11 . The system of  claim 10 , wherein the EWP comprises:
 an auxiliary EWP which cools a heater, a turbocharger, and an inverter.   
     
     
         12 . The system of  claim 10 , wherein the EWP controller is further configured to detect the battery power that is supplied to the EWP by the battery or the IG power supplied by the IG power portion. 
     
     
         13 . The system of  claim 12 , wherein the EWP controller is further configured to receive a rotation speed command for the EWP from the ECU through the CAN. 
     
     
         14 . The system of  claim 13 , wherein the EWP controller is further configured to control the EWP in a normal mode based on commands from the ECU when the IG power is turned on and the CAN signal is normal. 
     
     
         15 . The system of  claim 13 , wherein the EWP controller is further configured to control the EWP in a limp-home mode when the IG power is turned on and the FSDS is normally inputted to the EWP controller while the CAN signal is not inputted to the EWP controller. 
     
     
         16 . The system of  claim 13 , wherein the EWP controller is further configured to control the EWP in a wake-up mode when the IG power is turned on and the FSDS is not normally inputted to the EWP controller while the CAN signal is not inputted to the EWP controller. 
     
     
         17 . The system of  claim 13 , wherein the EWP controller is further configured to control the EWP in a normal mode when the IG power is turned off and the CAN signal is normally inputted to the EWP controller, and
 set the EWP to enter a sleep mode when the IG power is turned off and the CAN signal is not normally inputted to the EWP controller.   
     
     
         18 . The system of  claim 17 , wherein the EWP is further configured to perform the sleep mode after a predetermined time has passed when the EWP is set to enter the sleep mode from the normal mode. 
     
     
         19 . A computer readable storage medium containing a computer program configured to cause an EWP controller to control an electric water pump (EWP) by the following method when read and processed by a computer system: receiving a controller area network (CAN) signal from an engine electronic control unit (ECU) to control the EWP through a controller area network (CAN);
 receiving a fail-safe digital signal (FSDS) that is related to a fail-safe control function of an engine or the EWP from the ECU; and controlling the EWP based on the CAN signal and the fail-safe digital signal.