Modifying PFI to DI ratio to mitigate engine knocking

In accordance with exemplary embodiments, methods and systems are provided for controlling knocking for an engine of a vehicle having a plurality of different types of fuel injectors and a combustion chamber. In an exemplary embodiment, the system includes one or more sensors of the vehicle and a processor. The one or more sensors are configured to measure an intensity of engine knocking for the engine. The processor is coupled to the one or more sensors, and is configured to at least facilitate adjusting a fuel injection ratio of respective amounts of fuel provided by the plurality of different types of fuel injectors to the combustion chamber, based on the intensity of the engine knocking.

INTRODUCTION

The technical field generally relates to the field of vehicles and, more specifically, to control of engine knocking in vehicles.

Many vehicles today have drive systems that include engines, such as internal combustion engines. However, such engines may experience knocking under certain conditions.

Accordingly, it is desirable to provide systems and methods for controlling knocking in engines of vehicles. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this

SUMMARY

In accordance with an exemplary embodiment, a method is provided for controlling knocking for an engine of a vehicle having a plurality of different types of fuel injectors and a combustion chamber, the method including: measuring, via one or more sensors of the vehicle, an intensity of engine knocking for the engine; and adjusting, via instructions provided by a processor of the vehicle, a fuel injection ratio of respective amounts of fuel provided by the plurality of different types of fuel injectors to the combustion chamber, based on the intensity of the engine knocking.

Also in an exemplary embodiment, the plurality of different types of fuel injectors include a port fuel injector and a direct fuel injector; and the step of adjusting the fuel injection ratio includes simultaneously, in accordance with the instructions provided by the processor: reducing an amount of fuel provided by the port fuel injector to the combustion chamber based on the intensity of the engine knocking; and increasing an amount of fuel provided by the direct fuel injector to the combustion chamber based on the intensity of the engine knocking.

Also in an exemplary embodiment, the reducing of the amount of fuel provided by the port fuel injector to the combustion chamber and the increasing of the amount of fuel provided by the direct fuel injector to the combustion chamber are based on the intensity of the engine knocking in combination with a look-up table stored in a computer memory.

Also in an exemplary embodiment, the step of adjusting the fuel injection ratio includes adjusting, via the instructions provided by the processor, the fuel injection ratio only on a further condition that the intensity of the engine knocking is greater than a predetermined engine knock intensity threshold.

Also in an exemplary embodiment, the method further includes: determining, via the processor using updated sensor data from the one or more sensors, whether the intensity of the engine knocking is still greater than the predetermined engine knock intensity threshold, after an initial adjustment of the fuel injection ratio; and when it is determined that the intensity of the engine knocking is still greater than the predetermined engine knock intensity threshold after the initial adjustment of the fuel injection ratio, then subsequently, in accordance with further instructions provided by the processor: further reducing the amount of fuel provided by the port fuel injector to the combustion chamber; and further increasing the amount of fuel provided by the direct fuel injector to the combustion chamber.

Also in an exemplary embodiment, the method further includes: returning the fuel injection ratio to its original prior to the adjusting, in accordance with further instructions provided by the processor, when it is determined that the intensity of the engine knocking is no longer greater than the predetermined engine knock intensity threshold.

In accordance with another exemplary embodiment, a system is provided for controlling knocking for an engine of a vehicle having a plurality of different types of fuel injectors and a combustion chamber, the system including one or more sensors of the vehicle and a processor. The one or more sensors are configured to measure an intensity of engine knocking for the engine. The processor is coupled to the one or more sensors, and is configured to at least facilitate adjusting a fuel injection ratio of respective amounts of fuel provided by the plurality of different types of fuel injectors to the combustion chamber, based on the intensity of the engine knocking.

Also in an exemplary embodiment, the one or more sensors include a plurality of electric sensors of the engine of the vehicle that are configured to measure intensities of one or more frequencies associated with engine knocking, and wherein the intensity of the engine knocking is based on the measured intensities of the one or more frequencies.

Also in an exemplary embodiment: the plurality of different types of fuel injectors include a port fuel injector and a direct fuel injector; and the processor is further configured to at least facilitate simultaneously: reducing an amount of fuel provided by the port fuel injector to the combustion chamber based on the intensity of the engine knocking; and increasing an amount of fuel provided by the direct fuel injector to the combustion chamber based on the intensity of the engine knocking.

Also in an exemplary embodiment, the processor is further configured to at least facilitate reducing the amount of fuel provided by the port fuel injector to the combustion chamber and increasing the amount of fuel provided by the direct fuel injector to the combustion chamber based on the intensity of the engine knocking in combination with a look-up table stored in a computer memory.

Also in an exemplary embodiment, the processor is further configured to at least facilitate adjusting the fuel injection ratio only on a further condition that the intensity of the engine knocking is greater than a predetermined engine knock intensity threshold.

Also in an exemplary embodiment, the processor is further configured to at least facilitate: determining, using updated sensor data from the one or more sensors, whether the intensity of the engine knocking is still greater than the predetermined engine knock intensity threshold, after an initial adjustment of the fuel injection ratio; and when it is determined that the intensity of the engine knocking is still greater than the predetermined engine knock intensity threshold after the initial adjustment of the fuel injection ratio, then subsequently: further reducing the amount of fuel provided by the port fuel injector to the combustion chamber; and further increasing the amount of fuel provided by the direct fuel injector to the combustion chamber.

Also in an exemplary embodiment, the processor is further configured to at least facilitate returning the fuel injection ratio to its original prior to the adjusting, when it is determined that the intensity of the engine knocking is no longer greater than the predetermined engine knock intensity threshold.

In another exemplary embodiment, a vehicle is provided that includes an engine, one or more sensors, and a processor. The engine has a plurality of different types of fuel injectors and a combustion chamber. The one or more sensors are configured to measure an intensity of engine knocking for the engine. The processor is coupled to the one or more sensors, and is and that is configured to at least facilitate adjusting a fuel injection ratio of respective amounts of fuel provided by the plurality of different types of fuel injectors to the combustion chamber, based on the intensity of the engine knocking.

Also in an exemplary embodiment, the one or more sensors include a plurality of electric sensors of the engine of the vehicle that are configured to measure intensities of one or more frequencies associated with engine knocking, and wherein the intensity of the engine knocking is based on the measured intensities of the one or more frequencies.

Also in an exemplary embodiment: the plurality of different types of fuel injectors include a port fuel injector and a direct fuel injector; and the processor is further configured to at least facilitate simultaneously: reducing an amount of fuel provided by the port fuel injector to the combustion chamber based on the intensity of the engine knocking; and increasing an amount of fuel provided by the direct fuel injector to the combustion chamber based on the intensity of the engine knocking.

Also in an exemplary embodiment, the processor is further configured to at least facilitate reducing the amount of fuel provided by the port fuel injector to the combustion chamber and increasing the amount of fuel provided by the direct fuel injector to the combustion chamber based on the intensity of the engine knocking in combination with a look-up table stored in a computer memory.

Also in an exemplary embodiment, the processor is further configured to at least facilitate adjusting the fuel injection ratio only on a further condition that the intensity of the engine knocking is greater than a predetermined engine knock intensity threshold.

Also in an exemplary embodiment, the processor is further configured to at least facilitate: determining, using updated sensor data from the one or more sensors, whether the intensity of the engine knocking is still greater than the predetermined engine knock intensity threshold, after an initial adjustment of the fuel injection ratio; and when it is determined that the intensity of the engine knocking is still greater than the predetermined engine knock intensity threshold after the initial adjustment of the fuel injection ratio, then subsequently: further reducing the amount of fuel provided by the port fuel injector to the combustion chamber; and further increasing the amount of fuel provided by the direct fuel injector to the combustion chamber.

Also in an exemplary embodiment, the processor is further configured to at least facilitate returning the fuel injection ratio to its original prior to the adjusting, when it is determined that the intensity of the engine knocking is no longer greater than the predetermined engine knock intensity threshold.

DETAILED DESCRIPTION

FIG. 1illustrates a vehicle100, according to an exemplary embodiment. As described in greater detail further below, the vehicle100includes a drive system104with an engine150having a port fuel injector156and a direct fuel injector158. Also as described in greater detail further below and depicted inFIG. 1, the vehicle100also includes a control system102that controls engine knocking of the engine150based on control of port fuel injector156and the direct fuel injector158.

In certain embodiments, the vehicle100comprises an automobile. In various embodiments, the vehicle100may be any one of a number of different types of automobiles, such as, for example, a sedan, a wagon, a truck, or a sport utility vehicle (SUV), and may be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD) or all-wheel drive (AWD), and/or various other types of vehicles in certain embodiments. In certain embodiments, the vehicle100may also comprise a motorcycle and/or one or more other types of vehicles. In addition, in various embodiments, it will also be appreciated that the vehicle100may comprise any number of other types of mobile platforms.

In the depicted embodiment, the vehicle100includes a body110that substantially encloses other components of the vehicle100. Also in the depicted embodiment, the vehicle100includes a plurality of axles112and wheels114. The wheels114are each rotationally coupled to one or more of the axles112near a respective corner of the body110to facilitate movement of the vehicle100. In one embodiment, the vehicle100includes four wheels114, although this may vary in other embodiments (for example for trucks and certain other vehicles).

The drive system104drives the wheels114. In the depicted embodiment, the drive system104comprises a propulsion system, and includes the above-referenced engine150. In various embodiments, the engine150comprises an internal combustion engine, such as a gasoline or diesel fueled combustion engine.

In various embodiments, the engine150includes a combustion chamber152and an intake valve154, along with the above-referenced port fuel injector156and direct fuel injector158. In various embodiments, the direct fuel injector158is directly coupled to the combustion chamber152, and provides fuel directly to the combustion chamber152. Also in various embodiments, the port fuel injector156is directly coupled to the intake valve154, and supplies fuel indirectly to the combustion chamber152via the intake valve154, for example when the intake valve154is open.

In various embodiments, the control system102provides instructions for controlling the drive system104, including for controlling the engine150. In various embodiments, the control system102comprises an engine control unit (ECU) for the engine150. Also in various embodiments, among other functionality, the control system102selectively controls operation of the port fuel injector156and the direct fuel injector158, including respective ratios of fuel provided therefrom to the combustion chamber152, to control knocking for the engine150based on the intensity of the engine knocking, while otherwise optimizing performance for the engine150(e.g., in terms of torque, fuel economy, and/or other factors). In various embodiments, the control system102provides these functions in accordance with the steps of the process200described further below in connection with theFIG. 2.

As depicted inFIG. 1, in various embodiments, the control system102includes a sensor array120and a controller130.

In various embodiments, the sensor array120includes sensors for measuring sensor data. As depicted inFIG. 1, in various embodiments, the sensor array120includes one or more engine sensors122. In various embodiments, the engine sensors122comprise one or more electric sensors of the engine150that detect engine knocking and that measure an intensity of knocking for the engine150. In certain embodiments, the engine sensors122include one or more piezoelectric sensors that provide a voltage output in response to vibrational energy (in certain embodiments, in the range of 3kHz-20kHz); however, this may vary in other embodiments. In certain embodiments, the piezoelectric sensor works similar to a microphone where a piezoelectric crystal generates a varying voltage based on engine vibration intensity, and this voltage signal is sent to the control system102where it is processed. In various embodiments, the engine sensors122are attached to, disposed within, or otherwise disposed in proximity to the combustion chamber152. Also in various embodiments, the engine sensors122detect frequencies associated with engine knocking, and measure and record intensities of such frequencies during operation of the engine150.

In certain embodiments, the sensor array120may also include one or more other sensors124, for example for operation of the engine. For example, in certain embodiments, the other sensors124may include one or more ignition sensors for detecting when the engine150is turned on and/or running, and so on.

In various embodiments, the controller130is coupled to the sensor array120, and provides instructions for controlling the engine150(including controlling engine knocking based on control of the port fuel injector156and the direct fuel injector158) based on the sensor data (including as to the intensity of the engine knocking). As depicted inFIG. 1, in various embodiments, the controller130comprises a computer system comprising a processor132, a memory134, an interface, a storage device138, a bus140, and a disk146.

As depicted inFIG. 1, the controller130comprises a computer system. In certain embodiments, the controller130may also include the sensor array120and/or one or more other vehicle components. In addition, it will be appreciated that the controller130may otherwise differ from the embodiment depicted inFIG. 1. For example, the controller130may be coupled to or may otherwise utilize one or more remote computer systems and/or other control systems, for example as part of one or more of the above-identified vehicle devices and systems.

In the depicted embodiment, the computer system of the controller130includes a processor132, a memory134, an interface136, a storage device138, and a bus140. The processor132performs the computation and control functions of the controller130, and may comprise any type of processor or multiple processors, single integrated circuits such as a microprocessor, or any suitable number of integrated circuit devices and/or circuit boards working in cooperation to accomplish the functions of a processing unit. During operation, the processor132executes one or more programs142contained within the memory134and, as such, controls the general operation of the controller130and the computer system of the controller130, generally in executing the processes described herein, such as the process200discussed further below in connection withFIG. 2.

The memory134can be any type of suitable memory. For example, the memory134may include various types of dynamic random access memory (DRAM) such as SDRAM, the various types of static RAM (SRAM), and the various types of non-volatile memory (PROM, EPROM, and flash). In certain examples, the memory134is located on and/or co-located on the same computer chip as the processor132. In the depicted embodiment, the memory134stores the above-referenced program142along with one or more stored values144(e.g., including, in various embodiments, predetermined threshold values for controlling emissions of the drive system).

The bus140serves to transmit programs, data, status and other information or signals between the various components of the computer system of the controller130. The interface136allows communications to the computer system of the controller130, for example from a system driver and/or another computer system, and can be implemented using any suitable method and apparatus. In one embodiment, the interface136obtains the various data from the sensor array120, the drive system104, the drive system104, and/or one or more other components and/or systems of the vehicle100. The interface136can include one or more network interfaces to communicate with other systems or components. The interface136may also include one or more network interfaces to communicate with technicians, and/or one or more storage interfaces to connect to storage apparatuses, such as the storage device138.

The storage device138can be any suitable type of storage apparatus, including various different types of direct access storage and/or other memory devices. In one exemplary embodiment, the storage device138comprises a program product from which memory134can receive a program142that executes one or more embodiments of one or more processes of the present disclosure, such as the steps of the process200discussed further below in connection withFIG. 2. In another exemplary embodiment, the program product may be directly stored in and/or otherwise accessed by the memory134and/or one or more other disks146and/or other memory devices.

The bus140can be any suitable physical or logical means of connecting computer systems and components. This includes, but is not limited to, direct hard-wired connections, fiber optics, infrared and wireless bus technologies. During operation, the program142is stored in the memory134and executed by the processor132.

It will be appreciated that while this exemplary embodiment is described in the context of a fully functioning computer system, those skilled in the art will recognize that the mechanisms of the present disclosure are capable of being distributed as a program product with one or more types of non-transitory computer-readable signal bearing media used to store the program and the instructions thereof and carry out the distribution thereof, such as a non-transitory computer readable medium bearing the program and containing computer instructions stored therein for causing a computer processor (such as the processor132) to perform and execute the program. Such a program product may take a variety of forms, and the present disclosure applies equally regardless of the particular type of computer-readable signal bearing media used to carry out the distribution. Examples of signal bearing media include: recordable media such as floppy disks, hard drives, memory cards and optical disks, and transmission media such as digital and analog communication links. It will be appreciated that cloud-based storage and/or other techniques may also be utilized in certain embodiments. It will similarly be appreciated that the computer system of the controller130may also otherwise differ from the embodiment depicted inFIG. 1, for example in that the computer system of the controller130may be coupled to or may otherwise utilize one or more remote computer systems and/or other control systems.

FIG. 2is a flowchart of a process200for controlling engine knocking based on control of a port fuel injector and a direct fuel injector for the engine, in accordance with an exemplary embodiment. In various embodiments, the process200may be implemented in connection with the vehicle100ofFIG. 1, including the drive system104, the engine150, and the control system102thereof.

As depicted inFIG. 2, in various embodiments the process200begins at202. In certain embodiments, the process200begins when one or more events occur to indicate that a vehicle drive is taking place or about to take place, such as a driver, operator, or passenger entering the vehicle100, an engine or motor of the vehicle100being turned on, a transmission of the vehicle100being placed in a “drive” mode, or the like. In various embodiments, the event(s) triggering the starting of the process200are determined based on sensor data from one or more of the other sensors124ofFIG. 1(e.g., from ignition sensors in certain embodiments). Also in certain embodiments, the control system102is turned on, or “woken up” as part of step202.

In various embodiments, engine knocking is detected at204. In various embodiments, sensor data is obtained from the engine sensors122ofFIG. 1, and engine knocking is determined based on the sensor data from the engine sensors122. In various embodiments, during step204, electric sensors (e.g., piezoelectric sensors) of the engine sensors122detect knocking at one or more known knocking frequencies, along with an intensity of engine knocking at such known frequencies. In certain embodiments, the knock detection is performed using an algorithm inside the control system102that divides the voltage signal into bins that range (e.g., that range from 0 to 25Hz in certain embodiments); however, this may vary in other embodiments. Also in certain embodiments, consecutive frequency bins are grouped together into frequency “Ranges”. In certain embodiments, single or multiple ranges are selected (e.g., as a function of revolutions per minute in certain embodiments) for determining the intensity. In certain embodiments, during development the engine background noise intensity is determined, and the knock detection thresholds are calculated as a calibratable number of standard deviations above the adaptable background (non-knocking) average intensity.

In various embodiments, a determination is made as to whether a fuel injection ratio is greater than a predetermined threshold (step206). In various embodiments, this determination is made by the processor132ofFIG. 1based on current instructions provided thereto to the port fuel injector156and the direct fuel injector158ofFIG. 1. In certain embodiments, the fuel injection ratio (also referred to herein as “PDI Ratio”) comprises a ratio of (a) fuel provided by the port fuel injector156to the combustion chamber152to (b) the total fuel provided by the port fuel injector156and the direct fuel injector158combined to the combustion chamber152, in accordance with the following equation:
PDI Ratio=(PFI_Fuel)/(PFI_Fuel+DI_Fuel)(Equation 1)
in which PFI_Fuelrepresents the amount of fuel provided by the port fuel injector156to the combustion chamber and DI_Fuelrepresents the amount of fuel provided by the direct fuel injector158to the combustion chamber152.

Also in various embodiments, the predetermined threshold of step206is stored in the memory134as a stored value144thereof. In certain embodiments, the predetermined threshold of step206is equal to zero. In certain other embodiments, the predetermined threshold of step206may be approximately equal to zero, or some predetermined amount above zero.

In various embodiments, if it is determined in step206that the PDI ratio is not greater than the predetermined threshold ofFIG. 1(e.g., zero, in one embodiment), the process then proceeds to step208. During step208, traditional knock control techniques are employed, instead of adjusting the PDI ratio. Specifically, in certain embodiments, during step208, the processor132ofFIG. 1provides instructions to the drive system104for a reduction in spark provided for the combustion chamber152ofFIG. 1. In certain embodiments, the process then terminates at step218. In certain embodiments, the process200may instead repeat so long as the engine150is operating before termination of the process200.

Conversely, in various embodiments, if it is instead determined in step206that the PDI ratio is greater than the predetermined threshold ofFIG. 1(e.g., zero, in one embodiment), the process then proceeds instead to step210. During step210, the PDI ratio is reduced by an initial amount. Specifically, in various embodiments, the processor132ofFIG. 1provides instructions to the drive system104to decrease the PDI ratio by an initial amount. In certain embodiments, the PDI ratio is reduced in step210by simultaneously (a) decreasing the amount of fuel provided by the port fuel injector156the combustion chamber152; and (b) increasing the amount of fuel provided by the direct fuel injector158to the combustion chamber152, by respective initial amounts. In certain embodiments, the amounts of the decrease for the port fuel injector156and the increase for the direct fuel injector158are determined by the processor132based on a look-up table (e.g., stored in the memory134ofFIG. 1as stored values144thereof) based on the intensity of the knocking (e.g., as determined by the engine sensors122). Also in various embodiments, the instructions for the decrease in the PDI ratio in this manner are made by the processor132ofFIG. 1and implemented by port fuel injector156(with decreased fuel provided to the combustion chamber152) and the direct fuel injector158(with increased fuel provided to the combustion chamber152).

In various embodiments, a determination is made as to whether a knock intensity is greater than a predetermined threshold (step212). In various embodiments, during step212, the processor132ofFIG. 1determines whether, after the PDI ratio reduction of step210, engine knocking is still present with an intensity that is greater than a predetermined engine knock threshold. In certain embodiments, the engine knock intensity refers to an intensity of a frequency of engine knocking as detected or measured by the engine sensors122ofFIG. 1. Also in certain embodiments, this determination is made by the processor132based on new or updated sensor readings from the engine sensors122ofFIG. 1.

Also in various embodiments, the predetermined engine knock threshold of step212is stored in the memory134as a stored value144thereof. In certain embodiments, the predetermined engine knock threshold of step212is equal to zero. In certain other embodiments, the predetermined engine knock threshold of step212may be approximately equal to zero, or some predetermined amount above zero. In various embodiments, frequencies of knock events and intensity thresholds are dependent on the particular engine of the vehicle, including the bore diameter of the engine. In certain embodiments, the frequencies of knock events may be in the range of 5 to 20 kHz for certain engine types, and the intensity thresholds may be in the range of 0 to 5 for certain engine types. However, these values may vary in various different embodiments and for various types of engine designs.

In various embodiments, if it is determined in step212that the engine knock intensity is greater than the predetermined engine knock threshold of step212, then process returns to the above-described step206, in a new iteration. In various embodiments, steps206-212thereafter repeat in new iterations (with further reductions in the PDI ratio made as required in step210) until a determination is made in an iteration of step212that the engine knock intensity is no longer greater than the predetermined engine knock threshold of step212.

In various embodiments, once it is determined in an iteration of step212that the engine knock intensity is less than or equal to the predetermined engine knock threshold of step212, the process then proceeds to step214, described below.

In various embodiments, during step214, a determination is made as to whether the fuel injector ratio has returns to a prior level. In various embodiments, during step214, the processor132ofFIG. 1determines whether the current PDI ratio has returned to its normal or standard operating PDI level, for example prior to the detection of the engine knocking and prior to the adjustment(s) in the iteration(s) of step210.

In various embodiments, if it is determined in step214that the PDI has not returned to its prior level (e.g., the PDI ratio that was present prior to the detection of the engine knocking and prior to the adjustment(s) in the iteration(s) of step210), then the process proceeds to step216, in which the PDI ratio is increased. In various embodiments, the processor132ofFIG. 1provides instructions to the port fuel injector156and the direct fuel injector158ofFIG. 1by simultaneously (a) increasing the amount of fuel provided by the port fuel injector156the combustion chamber152; and (b) decreasing the amount of fuel provided by the direct fuel injector158to the combustion chamber152, in respective amounts required to return the PDI ratio to its prior value. Also in various embodiments, the process then returns to step212in a new iteration for confirmation that engine knock intensity is still not greater than the predetermined engine knock threshold of step212, and steps212-216thereafter repeat in subsequent iterations until a determination is made during an iteration of step214that the PDI ratio has returned to its prior value.

In various embodiments, once it is determined in step214that the PDI ratio has returned to its prior value, then in various embodiments the process terminates at step218. As noted above, in certain embodiments the process200may instead repeat so long as the engine150is operating before termination of the process200.

Accordingly, methods and systems, are provided for controlling engine knock in vehicles. In various embodiments, the disclosed methods and systems provide for reducing engine knock intensity by adjusting a ratio of fuel provided by different types of fuel injectors (namely, one or more port fuel injectors and one or more direct fuel injectors) to the combustion chamber of the engine based on the knock intensity. In various embodiments, by controlling engine knock in this manner, the disclosed methods and systems are able to reduce engine knocking without having to reduce spark for the engine. Instead, the disclosed methods and systems are able to reduce engine knocking while maintaining optimal levels of spark for the engine as well as while maintaining optimal levels of fuel economy and torque for the engine and/or for the vehicle.

It will be appreciated that the systems, vehicles, applications, and implementations may vary from those depicted in the Figures and described herein. For example, in various embodiments, the vehicle100, control system102, drive system104, engine150, components thereof, and/or other components may differ from those depicted inFIG. 1and/or described above in connection therewith. It will also be appreciated that the steps of the process200may differ, and/or that various steps thereof may be performed simultaneously and//or in a different order, than those depicted inFIG. 2and/or described above.