Claims:WE CLAIM:
1. A control unit (100) for diagnosing health of a fuel pump (50) of a vehicle (10), the control unit (100) in communication with a fuel injector (102) and the fuel pump (50), the control unit (100) configured to:
determine speed of a motor (52) of the fuel pump (50) based on current drawn by the motor (52);
determine fuel flow rate based on one or more parameters of the motor (52);
determine pressure in a fuel line (54) connecting the fuel pump (50) and the fuel injector (102) for a predetermined time “T”,
determine a first fuel flow rate for the predetermined time “T”; and
determine a second fuel flow rate after the predetermined time “T”, wherein the control unit (100) diagnoses the fuel pump (50) as faulty when at least one of the first fuel flow rate and the second fuel flow rate being greater or lower than a threshold range of fuel flow rate or diagnoses the fuel pump (50) as not faulty when at least one of the first fuel flow rate and the second fuel flow rate being within the threshold range of fuel flow rate.

2. The control unit (100) as claimed in claim 1, wherein the control unit (100) is configured to determine motor current value during fuel priming and compare the determined motor current value with a threshold current value.

3. The control unit (100) as claimed in claim 2, wherein the control unit (100) is configured to diagnose the fuel pump (50) as faulty when the motor current is higher than the threshold current value and display an alert on an instrument cluster (32) about servicing of the fuel pump (50).

4. The control unit (100) as claimed in claims 1 and 3, the control unit (100) is configured to disable mobility of the vehicle (10) when the fuel pump (50) is determined to be faulty.

5. The control unit (100) as claimed in claim 1, wherein the control unit (100) comprises a motor current detection module (106) which is configured for determining current drawn by the motor (52) of the fuel pump (50).

6. The control unit (100) as claimed in claim 1, wherein the control unit (100) comprises a motor speed computing module (108) which is configured for determining speed of the motor (52) based on the current drawn by the motor (52).

7. The control unit (100) as claimed in claim 1, wherein the control unit (100) comprises a fuel flow rate computing module (110) which is configured for determining the fuel flow rate based on one or more parameters of the motor (52).

8. The control unit (100) as claimed in claim 1, wherein the control unit (100) comprises a fuel line pressure computing module (112) which is configured for determining pressure of the fuel in the fuel line (54) connecting the fuel pump (50) and the fuel injector (102) for a predetermined time.

9. The control unit (100) as claimed in claim 1, wherein the threshold range of fuel flow rate is in a range of 1 litre per hour to 10 litres per hour.

10. The control unit (100) as claimed in claim 1, wherein the one or more parameters of the motor (52) comprises motor speed, viscosity of fuel, construction and dimension of the fuel pump (50) and dimension of a fuel hose.

11. The control unit (100) as claimed in claim 1, wherein the control unit (100) is configured to communicate a signal to the instrument cluster (32) of the vehicle (10) to display diagnoses of the fuel pump (50) onto the instrument cluster (32).

12. A method (200) for diagnosing health of a fuel pump (50) of a vehicle (10), the method comprising:
determining (202), by a control unit (100), speed of a motor (52) of the fuel pump (50) based on current drawn by the motor (52);
determining (204), by the control unit (100), a fuel flow rate based on one or more parameters of the motor (52);
determining (206), by the control unit (100), a pressure in a fuel line (54) connecting the fuel pump (50) and a fuel injector (102) for a predetermined time “T”,
determining (208), by the control unit (100), a first fuel flow rate for the predetermined time “T”; and
determining (210), by the control unit (100), a second fuel flow rate after the predetermined time “T”,
wherein when (212) at least one of the first fuel flow rate and the second fuel flow rate is greater or lower than a threshold range of fuel flow rate, the control unit (100) diagnoses the fuel pump (50) as faulty or when (214) at least one of the first fuel flow rate and the second fuel flow rate is within the threshold range of fuel flow rate, the control unit (100) diagnoses the fuel pump (50) as not faulty.

13. The method (200) as claimed in claim 12, wherein the control unit (100) is configured to determine motor current value during fuel priming and compare the determined motor current value with a threshold current value.

14. The method (200) as claimed in claim 13, wherein the control unit (100) is configured to diagnose the fuel pump (50) as faulty when the motor current is higher than the threshold current value and display an alert on an instrument cluster (32) about servicing of the fuel pump (50).

15. The method (200) as claimed in claims 12 and 14, the control unit (100) is configured to disable mobility of the vehicle (10) when the fuel pump (50) is determined to be faulty.

, Description:FIELD OF THE INVENTION
[001] The present invention relates toa control unit and a method for diagnosing health of a fuel pump of a vehicle.

BACKGROUND OF THE INVENTION
[002] Conventional two-wheeled internal combustion vehicles have used carburettor for controlling air-fuel mixture to engine. Due to stringent emission norms, the use of carburettor has been switched over to an Electronic Fuel Injection (EFI) system in the two-wheeled internal combustion vehicles. Typically, the EFI system in the two-wheeled vehicles having internal combustion engines use various sensors and actuators to control engine and meet the emission norms, thereby achieving better fuel economy and driveability requirements of the vehicle. All EFI systems in the two-wheeled vehicles typically use a fuel injector to atomize the fuel and a fuel pump is used to deliver the fuel at a desired pressure to a fuel injector. The fuel pump can be operated either mechanically or electrically. The electrically operated in-tank fuel pump module used in the two-wheeled vehicles have the components including, but not limited to, an electric fuel pump unit, a filter unit, a pressure regulator, check valves, springs and an electrical connector. The electric fuel pump motor can be a brushed DC motor, a brushless or a reciprocating type.
[003] In one kind of existing electrically operated fuel injection, when the fuel pressure in a fuel line is lower than a predetermined level, the electric power consumption of the motor is calculated. If the motor power consumption is normal, then it is determined as failure of a pump part. If the motor power consumption is abnormal, then it is determined as failure of a motor part. The motor unit fault determination in this kind of electrically operated fuel injection based on power consumed by the fuel pump drive will not be able to accurately determine the exact failure mode in the motor.
[004] In another kind of electrically operated fuel injection system, a pump inrush current during starting of the pump is used to detect brush deterioration. This system teaches a method of detecting the failure of a fuel pump motor of brush type.
[005] In the above-mentioned existing systems, fuel pump failure diagnosis is based on the fuel line pressure and the motor power consumption. In all of these cases, a pressure sensor has to be fitted in the fuel line to diagnose fuel pump failure. Thus, these systems and methods involve using additional components such as the pressure sensor for determining the problem in the fuel pump performance.
[006] In many other conventional vehicles, the fuel pump electrical fault detection is performed by an Electronic Control Unit (ECU) based on a voltage level. But the deterioration in the fuel pump performance over a period of time is not detected by the ECU. For example, the method which involves diagnosing circuit continuity-based failures involves the ECU performing electrical fault detection based on the voltage. If no voltage is received for a predetermined time, it is diagnosed as an open circuit fault. If the voltage received is greater than a predetermined value over a predetermined time, then it is diagnosed as short to battery fault. However, with these methods, it may still not be possible to detect the deterioration of the fuel pump performance.
[007] Thus, the internal combustion vehicles incorporating EFI system use electric fuel pump module having major child parts like pump unit and the mechanical pressure regulator. The fuel pump is controlled by an ECU directly or through a relay. In case of direct control of fuel pump by ECU, motor power consumption can be computed by the ECU. But in case of indirect control of fuel pump through relay, it is possible to monitor power consumption only if the pump voltage and current are available as a feedback to the ECU. In either of the above-mentioned cases, the fuel pump malfunction (short to ground, short to battery, open circuit) can be diagnosed based on the motor power consumption. In order for the ECU to check if the desired system pressure is being delivered by the pump, pressure sensor has to be used in the fuel line of the vehicle, where the pressure sensor input, and the motor power consumption are read by ECU to diagnose the fuel pump.
[008] Thus, there is a need in the art for a control unit and a method for diagnosing health of a fuel pump of a vehicle which could address at least the aforementioned problems and limitations.

SUMMARY OF THE INVENTION
[009] In one aspect, the present invention is directed to a control unit for diagnosing health of a fuel pump of a vehicle. The control unit is in communication with a fuel injector and the fuel pump of the vehicle. The control unit is configured to determine speed of a motor of the fuel pump based on current drawn by the motor. The control unit is further configured to determine fuel flow rate based on one or more parameters of the motor. The control unit is further configured to determine pressure in a fuel line connecting the fuel pump and the fuel injector for a predetermined time. The control unit is further configured to determine a first fuel flow rate for the predetermined time. The control unit is further configured to determine a second fuel flow rate after the predetermined time. The control unit diagnoses the fuel pump as faulty when at least one of the first fuel flow rate and the second fuel flow rate being greater or lower than a threshold range of fuel flow rate or diagnoses the fuel pump as not faulty when at least one of the first fuel flow rate and the second fuel flow rate being within the threshold range of fuel flow rate.
[010] In an embodiment, the control unit is configured to determine motor current value during fuel priming and compare the determined motor current value with a threshold current value.
[011] In a further embodiment, the control unit is configured to diagnose the fuel pump as faulty when the motor current is higher than the threshold current value and display an alert on an instrument cluster about servicing of the fuel pump.
[012] In a further embodiment, the control unit is configured to disable mobility of the vehicle when the fuel pump is determined to be faulty.
[013] In a further embodiment, the control unit includes a motor current detection module which is configured for determining current drawn by the motor of the fuel pump.
[014] In a further embodiment, the control unit includes a motor speed computing module which is configured for determining speed of the motor based on the current drawn by the motor.
[015] In a further embodiment, the control unit includes a fuel flow rate computing module which is configured for determining the fuel flow rate based on one or more parameters of the motor.
[016] In a further embodiment, the control unit includes a fuel line pressure computing module which is configured for determining pressure of the fuel in the fuel line connecting the fuel pump and the fuel injector for a predetermined time.
[017] In a further embodiment, the threshold range of fuel flow rate is in a range of 1 litre per hour to 10 litres per hour.
[018] In a further embodiment, the one or more parameters of the motor includes motor speed, viscosity of fuel, construction and dimension of the fuel pump and dimension of a fuel hose.
[019] In a further embodiment, the control unit is configured to communicate a signal to the instrument cluster of the vehicle to display diagnoses of the fuel pump onto the instrument cluster.
[020] In another aspect, the present invention is directed to a method for diagnosing health of a fuel pump of a vehicle. The method includes determining, by a control unit, speed of a motor of the fuel pump based on current drawn by the motor. The method further includes determining, by the control unit, a fuel flow rate based on one or more parameters of the motor. The method further includes determining, by the control unit, a pressure in a fuel line connecting the fuel pump and a fuel injector for a predetermined time. The method further includes determining, by the control unit, a first fuel flow rate for the predetermined time. The method further includes determining, by the control unit, a second fuel flow rate after the predetermined time. When at least one of the first fuel flow rate and the second fuel flow rate is greater or lower than a threshold range of fuel flow rate, the control unit diagnoses the fuel pump as faulty or when at least one of the first fuel flow rate and the second fuel flow rate is within the threshold range of fuel flow rate, the control unit diagnoses the fuel pump as not faulty.

BRIEF DESCRIPTION OF THE DRAWINGS
[021] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a schematic block diagram of a vehicle having a control unit for diagnosing health of a fuel pump of the vehicle, in accordance with an embodiment of the present invention.
Figure 2 illustrates a schematic block diagram of the control unit, in accordance with an embodiment of the present invention.
Figure 3 illustrates a flowchart for a method for diagnosing health of the fuel pump of the vehicle, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[022] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. In the ensuing exemplary embodiments, the vehicle is a two-wheeled vehicle. However, it is contemplated that the disclosure in the present invention may be applied to any automobile like a three-wheeled vehicle or a four-wheeled vehicle capable of accommodating the present subject matter without defeating the scope of the present invention.
[023] The present invention relates to a control unit and a method for diagnosing health of a fuel pump of a vehicle, for example a two-wheeled vehicle.
[024] Figure 1 illustrates a schematic block diagram of a vehicle 10 having a control unit 100 for diagnosing health of a fuel pump 50 of the vehicle 10, in accordance with an embodiment of the present invention. The term “health” is defined as a desired working condition of the fuel pump 50. The health condition of the fuel pump 50 is diagnosed to detect any fault in functioning or operation of the fuel pump 50. Further, the term “vehicle” as used in the present disclosure may include, but not limited to, a “two-wheeled vehicle”. The terms “vehicle” and “two-wheeled vehicle” as used herein are interchangeably used and they are one and the same. However, the term “vehicle” is used in place of the term “two-wheeled vehicle” for brevity.
[025] As illustrated in Figure 1, the vehicle 10 includes a fuel tank 40 that can be mounted onto a frame (not shown) of the vehicle 10. The frame may further include a head pipe (not shown) towards a front of two-wheeled vehicle 10 which may further support an instrument cluster 32 of the vehicle 10. The fuel tank 40 is provided with the fuel pump 50 and a motor 52 for supplying fuel to an internal combustion (IC) engine 20 of the vehicle 10. The term “fuel” may include, but not limited to, gasoline, ethanol and a mixture of gasoline and ethanol. In the illustrated embodiment, the fuel pump 50 is provided inside the fuel tank 40 and thus may be referred as an in-tank fuel pump. However, in another embodiment, the fuel pump 50 may also be provided outside the fuel tank 40. Thus, the mounting of the fuel pump 50 as illustrated in the present invention should not be meant to be limiting the scope of the present invention.
[026] In an embodiment, fuel from the fuel tank 40 is supplied to the IC engine 20 through a fuel injector 102. The fuel injector 102 is operated via signals / instructions received from the control unit 100 of the vehicle 10.
[027] In an embodiment, the control unit 100 can be configured within an Engine Control Unit (ECU) (not shown) of the vehicle 10. In another embodiment, the control unit 100 can be configured as a separate module which can be in communication with the ECU of the vehicle 10.
[028] In some embodiments, the control unit 100 may include one or more additional components such as, but not limited to, an input/output module and a pre-processing module. In another embodiment, the vehicle 10 may include more than one of same or similar control unit(s) 100.
[029] As illustrated in Figure 2, the control unit 100may include only a processor which may be required to process the received instructions / signals from one or more input devices. In one embodiment, the one or more input devices may include, but not limited to, a motor current detection module 106, a motor speed computing module 108, a fuel flow rate computing module 110, a fuel line pressure computing module 112. The control unit 100 is configured to process the inputs received from the one or more input devices and accordingly communicate signals to the fuel injector 102 for supplying fuel to the engine 20 or the instrument cluster 32 for alerting rider of the vehicle 10 about fault in the fuel pump 50 or stopping the operation of the fuel pump 50, thereby to stop mobility of the vehicle 10.
[030] In yet another embodiment, the control unit 100 can be in communication with an analytic module (not shown) which may be configured to perform additional analysis of the communication information received from the motor current detection module 106, the motor speed computing module 108, the fuel flow rate computing module 110 and the fuel line pressure computing module 112. Further, in some embodiments, a memory unit (not shown) may be provided which may be configured to be in communication with the control unit 100. The memory unit may be capable of storing machine executable instructions. Furthermore, the control unit 100may be capable of executing the machine executable instructions to perform the functions described herein.
[031] The control unit 100 is in communication with the components such as the pre-processing module and the analytic module. In another embodiment, the control unit 100 may be embodied as a multi-core processor, a single core processor, or a combination of one or more multi-core processors and one or more single core processors. For example, the control unit 100 is embodied as one or more of various processing devices, such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing circuitry with or without an accompanying DSP, or various other processing devices including integrated circuits such as, for example, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. In yet another embodiment, the control unit 100 may be configured to execute hard-coded functionality. In still another embodiment, the control unit 100 may be embodied as an executor of instructions, where the instructions are specifically configured to the control unit 100 to perform the steps or operations described herein for diagnosing health or fault of the fuel pump 50 of the vehicle 10.
[032] Referring again to Figures 1 and 2, the control unit 100 is in communication with the fuel injector 102 and the fuel pump 50 and is configured to diagnose the health and/or fault in the fuel pump 50. In an embodiment, the control unit 100 is configured to determine speed of the motor 52 of the fuel pump 50 based on current drawn by the motor 52. In one exemplary embodiment, the control unit 100 includes the motor current detection module 106 which is configured for determining current drawn by the motor 52 of the fuel pump 50. The control unit 100 further includes the motor speed computing module 108 which is configured for determining speed of the motor 52 based on the current drawn by the motor 52.
[033] The control unit 100 is further configured to determine a fuel flow rate based on one or more parameters of the motor 52. In an exemplary embodiment, the one or more parameters of the motor 52 includes, but not limited to, motor speed, viscosity of fuel, construction and dimension of the fuel pump 50 and dimension of a fuel hose (not shown). In an exemplary embodiment, the control unit 100 includes the fuel flow rate computing module 110 which is configured for determining the fuel flow rate based on the one or more parameters of the motor 52.
[034] The control unit 100 is further configured to determine pressure in a fuel line 54 connecting the fuel pump 50 and the fuel injector 102 for a predetermined time “T”. In an exemplary embodiment, the control unit 100 includes the fuel line pressure computing module 112 which is configured for determining pressure of the fuel in the fuel line 54 connecting the fuel pump 50 and the fuel injector 102 for the predetermined time “T”. The term “predetermined time” as used in the present disclosure is defined as a time taken to reach a desired pressure in the fuel line 54 for fuel priming operation. The predetermined time “T” may range from 0 to 3 seconds.
[035] In another exemplary embodiment, the fuel flow rate computing module 110 of the control unit 100 is configured to determine a first fuel flow rate for the predetermined time “T” and determine a second fuel flow rate after the predetermined time “T”. The control unit 100 diagnoses the fuel pump 50 as faulty when at least one of the first fuel flow rate and the second fuel flow rate is greater or lower than a threshold range of fuel flow rate. The control unit 100 diagnoses the fuel pump 50 as not faulty when at least one of the first fuel flow rate and the second fuel flow rate being within the threshold range of fuel flow rate. In an embodiment, the threshold range of fuel flow rate is in a range of 1 litre per hour to 10 litres per hour.
[036] In an embodiment, the control unit 100 is configured to determine a motor current value during the fuel priming and compare the determined motor current value with a threshold current value. The threshold current value is ranging between 0 and 3A, which is dependent on a type of fuel pump used in the vehicle. The control unit 100 is configured to diagnose the fuel pump 50 as faulty when the determined motor current value is higher than the threshold current value and communicate a signal to the instrument cluster 32 (shown in Figure 1) of the vehicle 10 to display diagnoses of the fuel pump 50 onto the instrument cluster 32. In other words, an alert is displayed on the instrument cluster 32 about servicing of the fuel pump 50. In one embodiment, the alert can be in the form of glowing a service reminder light (not shown) or a warning sound along with glowing the service reminder light in the instrument cluster 32. The control unit 100 is configured to disable mobility of the vehicle 10 when the fuel pump 50 is determined to be faulty.
[037] Figure 3 illustrates a flowchart for a method 200 for diagnosing health of the fuel pump 50 of the vehicle 10, in accordance with an embodiment of the present invention. In one embodiment, whenever an ignition key (not shown) is switched ON before start of the engine, the fuel pump 50 is primed to build the desired pressure in the fuel line 54 before the fuel injector 102 gets switched ON. During the fuel priming, the motor current value is observed by the control unit 100 based on battery voltage input. The control unit 100 compares the motor current value with the threshold current value and if the motor current value is higher than the threshold current value, then the control unit 100 alerts the user about fault in the fuel pump 50 and servicing of the fuel pump 50 on the instrument cluster 32. Accordingly, the control unit 100 disables mobility of the vehicle 10. If the current drawn by the motor 52 is lower than the threshold set value, then the method 200 is proceeded to a step 202.
[038] At the step 202 of the method 200, it includes determining by the control unit 100, speed of a motor 52 of the fuel pump 50 based on current drawn by the motor 52. At a step 204 of the method 200, it includes determining, by the control unit 100 a fuel flow rate based on one or more parameters of the motor 52. At a step 206 of the method 200, it includes determining, by the control unit 100, a pressure in the fuel line 54 connecting the fuel pump 50 and a fuel injector 102 for a predetermined time “T”. At a step 208 of the method 200, it includes determining, by the control unit 100, a first fuel flow rate for the predetermined time “T”. At a step 210 of the method 200, it includes determining, by the control unit 100, a second fuel flow rate after the predetermined time “T”. At a step 212, when at least one of the first fuel flow rate and the second fuel flow rate is greater or lower than a threshold range of fuel flow rate, the control unit 100 diagnoses the fuel pump 50 as faulty. At a step 214, when at least one of the first fuel flow rate and the second fuel flow rate is within the threshold range of fuel flow rate, the control unit 100 diagnoses the fuel pump 50 as not faulty.
[039] In yet another embodiment, if the fuel pump’s 50 performance deterioration is detected by the control unit 100 for a number of start cycles exceeding a predefined count over a period of time, then the control unit 100 alerts the user/rider about servicing of the fuel pump 50 in the instrument cluster 32. In an exemplary embodiment, the predefined count may be ranging from 0 to 5 and the period of time may be ranging from 0 to 3 seconds.
[040] Advantageously, the present invention diagnoses in-tank electric fuel pump in two-wheeled or three-wheeled vehicles incorporating Electronic Fuel Injection (EFI) system. The method disclosed in the present invention can also be applied for brushed DC motor based fuel pump and reciprocating type pump. Further, the present invention is applicable for hybrid-electric vehicles having an internal combustion engine with electronic fuel injection system.
[041] The present invention takes into account the predetermined time “T” taken for building pressure in the fuel line and determine the motor speed and the fuel flow rate after the build-up of pressure in the fuel line beyond the predetermined time “T”. Thus, the present invention is able to eliminate the use of fuel pressure sensor in the fuel line. Further, the present invention provides weight reduction, part reduction and consequently cost reduction since the diagnosis of fuel pump is carried out without using the fuel pressure sensor in the fuel line.
[042] The present invention enables detecting the short circuit of the pump irrespective of the type of the motor used in the fuel pump, i.e., brushed DC motor or brushless DC motor, as the present invention does not take into account the brush resistance as disclosed in the prior art. Rather, the present invention calculates the motor current, motor speed and the fuel flow rate, based on which it determines whether the fuel pump has deteriorated or not.
[043] The present invention diagnoses the fuel pump failure right from the start of the vehicle, i.e., when the ignition key is turned ON and continue to diagnose when the vehicle is in running condition.
[044] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.