JP6388516B2 - Injection amount measuring apparatus and method - Google Patents

Description

  The present invention relates to an injection amount measuring apparatus and method.

  2. Description of the Related Art Conventionally, a technique for measuring the amount of fuel injection is known in order to test the efficiency and performance of fuel injection pump injection. In such measurement, it is necessary to perform arithmetic processing based on a signal detected by high-speed sampling and appropriately perform processing with a high load with respect to the sampling interval.

  For example, in Patent Document 1, in order to process periodically sampled digital data, processing with a large processing load is distributed and allocated to a plurality of processing steps for each unit period according to output timing, and processing load The intermediate processing result is held by an accumulator register dedicated to high processing.

JP 2007-257033 A

  However, if the sampling for detecting the signal becomes faster, the arithmetic processing to be completed between samplings may not be completed by the next sampling, and the processing may not be in time. In particular, in order to properly measure the fuel injection amount, a signal related to injection is detected using an interrupt for sampling at high speed, and the arithmetic processing related to the detected signal is completed by the next interrupt for sampling. There is a need to.

  Therefore, in the measurement of the fuel injection amount or the like, in the interruption in which the signal is periodically sampled at a high speed (for example, sampling frequency is 200 kHz, that is, sampling every 5 microseconds), the arithmetic processing (for example, FIR There is a need for an injection amount measuring device that can appropriately process (Finite Impulse Response) calculation and differential calculation for calculating the fuel injection rate.

  An object of the present invention is to provide an injection amount measuring apparatus and method capable of performing appropriate signal processing related to the injection amount of fuel in an interrupt for periodically sampling at high speed.

For example, when the sampling frequency for analyzing the characteristic tendency of the injection rate waveform is 200 kHz, the injection amount measuring apparatus performs sampling and interruption at interruption every 5 microseconds almost simultaneously with the processing executed in the main routine. It is necessary to perform arithmetic processing. Therefore, the injection amount measuring apparatus performs the following interrupt process substantially simultaneously with the process performed in the main routine.
(A) Interrupt processing (for example, FIR calculation, differential calculation) is performed by setting interrupts every 5 microseconds as one state and eight cycles (state 1 to state 8) as one cycle, and interrupt processing The main routine process is performed during the time when the process is not performed. This interrupt processing is performed in the following order when sampling signals for four channels (for example, channel 1 is a temperature signal, channel 2 is a pressure signal, channel 3 is an exhaust signal, and channel 4 is an external signal). .
(A-1) In state 1, a signal digital value obtained by digitally converting the voltage values of all channel signals (for example, the voltage values of the four channels) is obtained for calculation in the next cycle. The FIR calculation is collectively performed on the AD values of channel 1 for the eight states acquired in the cycle (AD values of signals converted in (A-8) described later, the same applies hereinafter).
(A-2) All channel signal digital values for calculation in the next cycle are acquired in state 2, and FIR calculation is collectively performed on the AD values of channel 2 for eight states acquired in the previous cycle. Is done.
(A-3) In state 3, all channel signal digital values for calculation in the next cycle are acquired, and differential calculation is collectively performed on the AD value of channel 2 for eight states acquired in the previous cycle. Is done. That is, the differential operation using the AD value of the pressure signal of the channel 2 is performed, and the injection rate is calculated.
(A-4) In state 4, all channel signal digital values for calculation in the next cycle are acquired, and FIR calculation is collectively performed on the channel 3 AD values for eight states acquired in the previous cycle. Is done.
(A-5) In state 5, all channel signal digital values for calculation in the next cycle are acquired, and FIR calculation is collectively performed on the AD values of channel 4 for eight states acquired in the previous cycle. Is done.
(A-6) In state 6, all channel signal digital values for calculation in the next cycle are acquired.
(A-7) In state 7, all channel signal digital values for calculation in the next cycle are acquired.
(A-8) In state 8, all channel signal digital values for calculation in the next cycle are acquired, and AD digital value conversion conversion (acquisition of signal digital values for eight states acquired in states 1 to 8) A process of converting the converted signal digital value into a digital value as an actual signal value, and the converted value is called an AD value of the signal).
The calculation result is output for each state.
(B) The signal processing related to the injection amount is performed by combining both the processing in the interrupt processing and the processing in the main processing. That is, processing that does not need to be performed in interrupt processing, for example, injection rate cutout, acquisition of a measurement enable state determination result, and the like are performed in the main processing when interrupt processing is not performed in each state.

Specifically, the following solutions are provided.
(1) An injection amount measuring device for measuring an injection amount of fuel, wherein an interrupt control means for generating an interrupt at every predetermined time, and each interrupt generated by the interrupt control means is set as one state, An interrupt processing unit that performs different processing for each state and performs signal processing of one cycle by combining a plurality of processing of the states, and the injection amount based on the signal processing by the interrupt processing unit And a main processing means for performing processing for measuring the injection amount.

  According to the configuration of (1), the injection amount measuring device according to (1) generates an interrupt at every predetermined time, sets each generated interrupt as one state, and performs different processing for each state. A process combining a plurality of states is set as a signal process of one cycle, and a process for measuring the fuel injection amount is performed based on the signal process.

That is, since the injection amount measuring device according to (1) is in a state in which different processing is performed for each interrupt, even if the interrupt for sampling the signal is, for example, a high-speed interrupt every 5 microseconds, Arithmetic processing related to the sampled signal can be calculated for each state, and each calculation can be completed by the next interrupt. And the injection quantity measuring device which concerns on (1) performs the process for measuring injection quantity by the signal processing which united the process completed for every interruption.
Therefore, the injection amount measuring apparatus according to (1) can perform appropriate signal processing relating to the fuel injection amount in the interrupt for sampling at high speed.

  (2) The process of the state includes a process of inputting all channel signals, a process of performing FIR calculation for each channel, and a process of performing differential operation for calculating the fuel injection rate. Different injection quantity measuring device according to (1).

  Therefore, the injection amount measuring apparatus according to (2) differs in processing including input of all channel signals, FIR calculation processing, and differentiation calculation processing for each state, so that an interrupt for sampling the signal is generated. For example, even for high-speed interruptions every 5 microseconds, the arithmetic processing relating to the sampled signal can be completed by the next interruption, and appropriate signal processing relating to the fuel injection amount can be performed. .

  (3) The interrupt control means includes an injection start delay time from the start of the injector drive signal to the start of the rise of the injection rate waveform, and an injection from the end of the injector drive signal to the end of the fall of the injection rate waveform. The injection amount measuring device according to (1) or (2), wherein an interruption can be generated at each predetermined time, with which the end delay time can be calculated with high accuracy.

  Therefore, the injection amount measuring apparatus according to (3) generates and generates an interrupt (for example, every 5 microseconds) for sampling at high speed in order to calculate the injection start delay time and the injection end delay time with high accuracy. In the performed high-speed sampling, it is possible to perform appropriate signal processing relating to the fuel injection amount.

  (4) A method executed by the injection amount measuring apparatus according to (1), wherein the interrupt processing unit sets each interrupt generated by the interrupt control unit as one state, and is different for each state. An interrupt processing step of performing processing and combining the processing of the plurality of states into one cycle of signal processing, and the main processing means, based on the signal processing by the interrupt processing step, the injection A main processing step for performing a process for measuring an amount.

  Therefore, the method according to (4) can perform appropriate signal processing relating to the fuel injection amount in the interruption for sampling at high speed.

ADVANTAGE OF THE INVENTION According to this invention, in the interruption for sampling at high speed, the appropriate signal processing regarding fuel injection amount measurement can be performed.
In the present invention, the process of inputting a signal, the process including the FIR operation and the differential operation are different for each interrupt. Therefore, even if the interrupt for sampling the signal is a high-speed interrupt every 5 microseconds, for example. The arithmetic processing relating to the sampled signal can be completed by the next interrupt. As a result, the present invention can perform appropriate signal processing relating to the fuel injection amount based on the completed arithmetic processing.

It is a block diagram which shows the structure of the injection quantity measuring device which concerns on one Embodiment of this invention. It is a figure which shows the example of the interruption process in the injection quantity measuring device which concerns on one Embodiment of this invention. It is a figure which shows the example of the signal detected by the injection quantity measuring device which concerns on one Embodiment of this invention. It is a flowchart of the interruption process in the injection quantity measuring device which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an injection amount measuring apparatus 10 according to an embodiment of the present invention. The injection amount measuring apparatus 10 includes an interrupt control unit 11, an interrupt processing unit 12, and a main processing unit 21. Each means will be described.

  The interrupt control means 11 generates an interrupt every predetermined time. Specifically, the interrupt control means 11 performs the injection start delay time from the start of the injector drive signal to the start of the rise of the injection rate waveform, and the injection from the end of the injector drive signal to the end of the fall of the injection rate waveform. An interruption is generated at predetermined time intervals that can calculate the end delay time with high accuracy. More specifically, the interrupt control means 11 accurately determines a periodic interruption (for example, an injection start delay time and an injection end delay time, or a fuel injection rate) based on a clock for operating the CPU of the injection amount measuring device 10. Interrupt for every 5 microseconds necessary to calculate well) is generated, and interrupt processing corresponding to the interrupt is started.

  The interrupt processing unit 12 sets each interrupt generated by the interrupt control unit 11 as one state, performs different processing for each state, and performs signal processing for one cycle by processing of a plurality of states. To do. The state processing includes processing for inputting a signal, processing for performing FIR calculation for each channel, and processing for performing differentiation for calculating the fuel injection rate, and the processing performed for each state is different. The interrupt processing means 12 performs signal processing of one cycle by processing performed in each state.

  The main processing means 21 performs processing for measuring the injection amount based on the signal obtained by the interrupt processing means 12 when interrupt processing is not performed. Specifically, the main processing means 21 detects the rise and fall of the injection rate waveform, calculates the fuel injection amount, and calculates the injection start delay time and the injection end delay time.

FIG. 2 is a diagram illustrating an example of interrupt processing in the injection amount measuring apparatus 10 according to an embodiment of the present invention. The table of FIG. 2 represents the states corresponding to the interrupts vertically, and represents the processing contents for each state horizontally. The table of FIG. 2 shows that states 1 to 8 are one cycle, and the cycle is repeated from 1 to n.
In the example of the table of FIG. 2, interrupt processing of processing 1 to 6 is executed at maximum in one state.
The process 1 is a process for periodically sampling the signals of all channels and acquiring a signal digital value for digital input. This process is a process of acquiring a signal digital value that is an output value of the AD converter of the sampled signal.
Process 2 is a DA value output process for periodically performing analog output. This process is, for example, a process of outputting an analog value of a calculation result of channels 1 to 4 for another application.
Process 3 is a FIFO (First In First Out) process for outputting input digital values in the order of input periodically. This process is, for example, a process of outputting the result of the differential calculation process in the order of acquisition for another application.
Process 4 is a measurement enable determination process. This process is a process for determining whether or not to perform the process in the main process.
Process 5 is an Angle Pulse state acquisition process. This process is a process for acquiring a value used in the main process.
Process 6 is a process for performing FIR calculation, differential calculation, or AD value conversion. That is, in state 1, channel 1 FIR operation is performed, in state 2, channel 2 FIR operation is performed, in state 3, channel 2 differential operation is performed, and in state 4, channel 3 FIR operation is performed. In state 5, channel 4 FIR calculation is performed, and in state 8, AD value conversion conversion (processing for converting the acquired signal digital value into a digital value as an actual signal value) is performed.
The example in the table of FIG. 2 indicates that in cycle 1, since there is no data sampled before this cycle, FIR calculation processing and differentiation calculation processing are not performed in processing 6 from state 1 to state 5. . Further, in the example of the table of FIG. 2, in cycle 1, for cycle 2, signal digital value acquisition processing is performed in processing 1 from state 1 to state 8, and AD value conversion conversion processing is performed in processing 6 in state 8. Represents that this is done.
Furthermore, in the example of the table of FIG. 2, in cycle 2 and subsequent cycles, FIR calculation processing and differential calculation processing are performed in processing 6 from state 1 to state 5 based on the AD value acquired in the previous cycle, and the next cycle For this reason, the signal digital value acquisition process is performed in the process 1 from the state 1 to the state 8, and the AD value conversion process is performed in the process 6 of the state 8.

FIG. 3 is a diagram illustrating an example of a signal detected by the injection amount measuring apparatus 10 according to an embodiment of the present invention. In the example of FIG. 3, the injector drive signal 100 indicating the start (injection start command) to the end (injection end command) of the signal for driving the injector, and the injection rate of the fuel injected according to the drive of the injector are shown. It is an example with the injection rate waveform 200 shown.
The injection amount measuring apparatus 10 samples an injector drive signal and a signal for calculating an injection rate at a high speed (for example, interrupt every 5 microseconds), and sets an interrupt cycle (interrupt every 5 microseconds as one state). By performing arithmetic processing (FIR calculation, differential calculation) between eight states in one cycle), the injection rate waveform 200 is restored with high accuracy, and the rising start point and the falling edge of the injection rate waveform 200 are restored. The end point can be detected with high accuracy.
Therefore, the injection amount measuring apparatus 10 starts from the start of the injector drive signal 100 to the injection start delay time SDT201 (300 microseconds to 500 microseconds) from the start of the rise of the injection rate waveform 200, and the end of the injector drive signal 100. The injection end delay time EDT202 until the end of the falling of the injection rate waveform 200 can be calculated with high accuracy, and the time resolution of the calculated time can be improved.

  FIG. 4 is a flowchart of interrupt processing in the injection amount measuring apparatus 10 according to an embodiment of the present invention. The injection amount measuring apparatus 10 includes a computer and its peripheral devices (particularly, an AD converter for acquiring an AD value of a signal, a DA converter for converting a digital value into an analog value, and a storage device for storing the AD value of the signal) Etc.) and software for controlling the hardware, and the following processing is processing executed by a control unit (for example, CPU) according to predetermined software. The interrupt process in the injection amount measuring apparatus 10 is started by an interrupt that is periodically generated (for example, every 5 microseconds) by the interrupt control unit 11 under an OS that performs real-time control. This flowchart shows the processing after the initial value of the state variable (for example, the value when the injection amount measuring device 10 is turned on is 1) is set.

  In step S101, the CPU (interrupt processing means 12) shifts the process to each process depending on the state. More specifically, when the remainder when the value of the state variable is divided by the number of states (for example, 8) is 1 (state 1), the CPU moves the process to step S102, and the remainder is 2 In the case of (State 2), the CPU moves the process to Step S103, and when the remainder is 3 (State 3), the CPU moves the process to Step S104, and when the remainder is 4 (State 4), The CPU moves the process to step S105. If the remainder is 5 (state 5), the CPU moves the process to step S106. If the remainder is 6 (state 6), the CPU moves the process to step S107. If the remainder is 7 (state 7), the CPU moves the process to step S108. If the remainder is 0 (state 8), the CPU moves the process to step S109.

  In step S102, the CPU (interrupt processing means 12, state 1) acquires and stores the signal digital values of channels 1 to 4, DA value output, FIFO output, Measurement Enable determination processing, and Angle Pulse state acquisition. Process. Then, the CPU performs the FIR calculation for channel 1 in a batch among the AD values stored in state 1 to state 8 of the previous cycle. Thereafter, the CPU moves the process to step S110.

  In step S103, the CPU (interrupt processing means 12, state 2) acquires the signal digital values of channels 1 to 4, stores them, and performs the same DA value output as in state 1 to the AnglePulse state acquisition process. Then, the CPU performs the FIR calculation of the channel 2 in a lump among the AD values stored in the state 1 to the state 8 of the previous cycle. Thereafter, the CPU moves the process to step S110.

  In step S104, the CPU (interrupt processing means 12, state 3) acquires the signal digital values of channels 1 to 4, stores them, and performs the same DA value output as in state 1 to the AnglePulse state acquisition process. Then, the CPU performs the differential operation of channel 2 in a lump among the AD values stored in state 1 to state 8 of the previous cycle. Thereafter, the CPU moves the process to step S110.

  In step S105, the CPU (interrupt processing means 12, state 4) acquires and stores the signal digital values of channels 1 to 4, and performs from the DA value output similar to state 1 to the Angle Pulse state acquisition process. Then, the CPU performs the FIR calculation of the channel 3 in a batch among the AD values stored in the state 1 to the state 8 of the previous cycle. Thereafter, the CPU moves the process to step S110.

  In step S106, the CPU (interrupt processing means 12, state 5) acquires the signal digital values of channels 1 to 4, stores them, and performs the same DA value output as in state 1 to the Angle Pulse state acquisition process. Then, the CPU collectively performs the FIR calculation of the channel 4 among the AD values stored in the state 1 to the state 8 of the previous cycle. Thereafter, the CPU moves the process to step S110.

  In step S107, the CPU (interrupt processing means 12, state 6) acquires and stores the signal digital values of channels 1 to 4, and performs from the DA value output similar to state 1 to the AnglePulse state acquisition process. Thereafter, the CPU moves the process to step S110.

  In step S108, the CPU (interrupt processing means 12, state 7) acquires and stores the signal digital values of channels 1 to 4, and performs from the DA value output similar to state 1 to the AnglePulse state acquisition process. Thereafter, the CPU moves the process to step S110.

  In step S109, the CPU (interrupt processing means 12, state 8) acquires and stores the signal digital values of channels 1 to 4, and performs from the DA value output similar to state 1 to the AnglePulse state acquisition process. Then, the CPU performs conversion conversion processing on the signal digital value stored in states 1 to 8, and stores the converted AD value for the next cycle. Thereafter, the CPU moves the process to step S110.

  In step S110, the CPU (interrupt processing means 12) adds 1 to the state variable. Thereafter, the CPU ends the process.

According to the present embodiment, the injection amount measuring apparatus 10 generates an interrupt every predetermined time (for example, the sampling frequency is 200 kHz, that is, the sampling period is 5 microseconds), and each generated interrupt is set as one state. A different process is performed for each state, and a process that combines the processes of a plurality of states is used as a signal process of one cycle, and a process for measuring the injection amount is performed based on the signal process. The state process includes a process for inputting a signal, a process for performing FIR calculation for each channel, and a process for performing differential operation for calculating the fuel injection rate, and the execution contents are different for each state.
Therefore, the injection amount measuring apparatus 10 completes the arithmetic processing related to the sampled signal by the next interrupt even if the interrupt for sampling the signal is a high-speed interrupt every 5 microseconds, for example. Can do.
Therefore, the injection amount measuring apparatus 10 generates an interruption every 5 microseconds necessary for improving the time resolution, and calculates the injection start delay time (SDT) and the injection end delay time (EDT) with high accuracy. It is possible.
Therefore, the injection amount measuring apparatus 10 can perform appropriate signal processing relating to the fuel injection amount in the interrupt for sampling at high speed.

As mentioned above, although embodiment of this invention was described, this invention is not restricted to embodiment mentioned above. The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.
In the present embodiment, an example in which eight states are defined as one cycle according to the definition by the calculation library used for FIR calculation and differentiation calculation is not limited to this. The plurality of states may be one cycle so that appropriate signal processing can be performed from the relationship between the interrupt interval and the processing time of the calculation.

DESCRIPTION OF SYMBOLS 10 Injection quantity measuring device 11 Interrupt control means 12 Interrupt processing means 21 Main processing means

Claims (3)

An injection amount measuring device for measuring an injection amount of fuel,
Interrupt control means for generating an interrupt every predetermined time;
Each interrupt generated by the interrupt control means is set to one state, and processing of the state includes processing for inputting a signal, processing for performing FIR calculation for each channel, and differential calculation for calculating the fuel injection rate. and a process of performing, performs different processing for each of the state, and an interrupt processing means for signal processing of one cycle by treatment combined processing of a plurality of said states,
From the result based on the signal processing by the interrupt processing means, main processing means for performing processing for measuring the injection amount;
An injection amount measuring device comprising: The interrupt control means includes an injection start delay time from the start of the injector drive signal to the start of rise of the injection rate waveform, and an injection end delay time from the end of the injector drive signal to the end of fall of the injection rate waveform. preparative as can be calculated with high accuracy, to generate an interrupt every predetermined time, the injection quantity measuring apparatus according to claim 1. A method executed by the injection amount measuring apparatus according to claim 1,
The interrupt processing unit sets each interrupt generated by the interrupt control unit as one state, and the processing of the state includes processing for inputting a signal, processing for performing FIR calculation for each channel, and fuel injection rate. An interrupt processing step for performing a different operation for each state, and performing signal processing of one cycle by processing a plurality of the states,
A main processing step in which the main processing means performs a process for measuring the injection amount from a result based on the signal processing in the interrupt processing step;
A method comprising:

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