JP4615004B2 - Method and apparatus for discriminating rotation direction of rotating body, and control device for internal combustion engine using the apparatus - Google Patents

Description

  The present invention relates to a method for determining the rotational direction of a rotating body, an apparatus therefor, and a control device for an internal combustion engine, and more specifically, a method for determining the rotational direction of a rotating body for determining the rotational direction of a rotating body in an internal combustion engine such as an automobile and the like. The present invention relates to an apparatus and a control apparatus for an internal combustion engine using the apparatus.

  Generally, in an internal combustion engine such as an automobile engine having a plurality of cylinders, fuel injection and ignition are performed for each cylinder. Therefore, cylinder discrimination is performed for each cylinder from the rotational position of the crankshaft and camshaft in the internal combustion engine. It is necessary to identify the cylinders that should perform fuel injection and ignition among these cylinders. Therefore, in order to know the rotation directions of the crankshaft and the camshaft, a signal rotor is attached to the crankshaft and the camshaft, and a crank angle sensor and a cam angle sensor are provided on the sides of the signal rotor.

In the signal rotor of the crankshaft, a plurality of protrusions are formed at predetermined intervals in the circumferential direction of the outer peripheral surface. As the crankshaft rotates, each projection sequentially passes the side of the crank angle sensor, and a pulse-like detection signal is output from the crank angle sensor. Further, in the signal rotor of the cam angle sensor, a predetermined number (for example, three) of protrusions are formed on the outer peripheral surface thereof. Then, as the cam shaft rotates, the protrusion passes by the side of the cam angle sensor, so that a detection signal is output from the cam angle sensor at predetermined intervals corresponding to the passage of the protrusion. As shown in FIG. 5 , a signal waveform having a LOW time of 45 μs during forward rotation and a signal waveform having a LOW time of 90 μs during reverse rotation are output to an engine control unit (hereinafter referred to as ECU). A crank angle sensor that has a function of generating pulses at different intervals during forward rotation and reverse rotation is generally called a crank angle sensor with a reverse rotation detection function.

  Based on the detection signals from the crank angle sensor and the cam angle sensor, the rotation directions of the crankshaft and the camshaft can be known. Cylinder discrimination is performed on the basis of the rotation directions of the crankshaft and camshaft, and the cylinders to be injected and ignited are identified (see, for example, Patent Document 1).

FIG. 6 is a diagram showing a count value a that periodically counts between 720 ° CA (crank angle) based on the compression top dead center (TDC) of the first cylinder, for example, and is shown in FIG . 7 described later . If the forward / reverse rotation direction is determined to be the forward rotation direction, the angle recognition value is counted up every time a pulse signal is input, and the position corresponding to the compression top dead center in the compression stroke of the first cylinder is counted. Initialized.

  Since the count value a is a basic count value for determining the engine stop angle and the restart initial injection cylinder, for example, when the count value a is erroneously calculated due to noise or the like, the stop value is stopped. The angle and restart initial injection cylinder determination accuracy are impaired, and desired control, for example, fuel injection and ignition timing control during restart after idle stop cannot be performed accurately.

FIG. 7 is a diagram illustrating an example of a crank angle calculation method when the engine rotates forward and reverse. If the crank angle count value a is rotating in the forward rotation direction, it may be counted up as described above. For example, the position of the compression top dead center of the first cylinder (720 ° CA). Thus, the count value a = 0 is initialized. Thereafter, when normal rotation is continued, it is only necessary to count up from a value of 0. On the other hand, in the case of reverse rotation, the count value a is counted down (for example, see Patent Document 2), contrary to the case of normal rotation.

JP 2005-233622 A JP 2006-214408 A

The crank angle detection means in the internal combustion engine disclosed in the patent document is a system for determining reverse rotation / forward rotation by using a reverse rotation / forward rotation signal output sensor by pulse, and the system configuration is as shown in FIG. The pulse output from the crank angle sensor 90 is input to a register 93 in a microcomputer 92 provided in the ECU 91. When the edge of the pulse is a falling edge, the edge input time is stored in the first register 93A, and when the edge of the pulse is a rising edge, the edge input time is stored in the second register 93B. ing.

More specifically, in the pulse shown in the time chart of FIG. 9 , since the input edge 100 is a falling edge, the edge input time T1 is stored in the first register 93A, and the input edge 101 is a rising edge. The edge input time T2 is stored in the second register 93B.

Thereafter, the S / W interrupt 102 is activated, and when the interrupt occurs, the rising edge 101 stored in the first register 93A is started from the input time T2 of the rising edge 101 stored in the second register 93B in the interrupt processing. The input time T1 of the downstream edge 100 is subtracted to determine the edge interval. This processing flow is shown in steps S110 to S113 in FIG. The description of FIG. 10 is omitted because it is the same as described above.

  For example, if the edge interval obtained as described above is LOW time of 45 μs, it is determined as the normal rotation direction, and if it is 90 μs LOW time, it is determined as the reverse rotation direction, and whether the engine rotation direction is the normal rotation direction. Determine if the direction is reverse. Then, when the direction is the normal rotation direction, the cylinder identification counter is counted up, and when the direction is the reverse rotation direction, the cylinder identification counter is counted down. The cylinder position to be ignited is identified from the value of the cylinder identification counter.

However, in the conventional system for detecting the crank angle in the internal combustion engine, as shown in FIG. 11 , the input time T1 of the falling edge 70 is stored in the first register 93A (see FIG. 8 ), and the second register 93B. When the input time T2 of the rising edge 71 is stored in (see FIG. 8 ), and then the interrupt 72 by S / W is started, an interrupt by another event such as an interrupt process by a cam angle sensor input has already been performed. When the processing is performed in a state where other interrupts are prohibited, the processing of the interrupt 72 by the S / W cannot be executed until the interruption is canceled.

That is, when the falling edge 73 is input before the S / W interrupt 72 occurs, the edge input time T3 is stored in the first register 93A (see FIG. 8 ), and the first register The input time T1 of the falling edge 70 stored in 93A is overwritten with the input time T3 of the falling edge 73.

After that, when the interrupt prohibition is canceled and the task is activated by the generation of the interrupt 72 by S / W, the input from the input time T2 of the rising edge 71 stored in the second register 93B (see FIG. 8 ) in the interrupt processing . Therefore, the input time T3 of the falling edge 73 stored in the first register 93A (see FIG. 8 ) is subtracted, and the value of the falling time T2−rising time T1 to be originally calculated cannot be obtained and measured. Since the value becomes a very large value and exceeds the determination value of 90 μs, there is a problem that it is determined that the low time is 90 μs even though the low time is 45 μs.

  As a result, it is erroneously determined whether the engine rotation direction is the forward rotation direction or the reverse rotation direction, and the cylinder identification counter is counted down. For this reason, there is a risk of damaging the internal combustion engine by making an erroneous ignition target cylinder and causing erroneous ignition.

  The present invention has been made to solve such a problem, and a method for determining the rotation direction of a rotating body without erroneously determining whether the rotation direction of the rotating body is a normal rotation direction or a reverse rotation direction. And an apparatus for the same.

  In another aspect of the invention, an internal combustion engine that determines whether the rotation direction of a rotating body used in an internal combustion engine is a forward rotation direction or a reverse rotation direction without error and prevents damage to the internal combustion engine due to erroneous ignition. An engine control apparatus is provided.

  According to the method of determining the rotational direction of a rotating body according to the present invention, the edge input time of a pulse signal continuously output from a sensor that generates pulses at different intervals between when the rotating body rotates in the forward direction and when it rotates in the reverse direction In a rotation direction determination method for a rotating body that is input to a computer and determines the rotation direction of the rotation body based on the edge input time, the input time of a falling edge of a pulse signal to be detected is input to the first register of the microcomputer. And storing the input time of the falling edge of the pulse signal immediately before the pulse signal to be detected in the second register of the microcomputer, and inputting the rising edge of the pulse signal output from the sensor. The time is stored in the third register of the microcomputer, and the input time of the falling edge is stored in the microcomputer. If the edge input time stored in the fourth register is earlier than the input time stored in the third register, the fourth register starts from the input time stored in the third register. Subtracted from the input time stored in is used as the measurement time between edges. If the edge input time stored in the fourth register is later than the input time stored in the third register, it is stored in the third register. The input time stored in the second register is compared with the input time stored in the second register. If the input time stored in the third register is earlier than the input time stored in the second register, it is stored in the third register. The time obtained by subtracting the input time stored in the second register from the input time is taken as the measurement time between edges, and the input time stored in the third register is less than the input time stored in the second register. For are those ones obtained by subtracting the input time from the input time stored in the third register is stored in the first register and measure the time between edges.

  In addition, the position detection device for a rotating body according to the present invention can detect the edge input time of a pulse signal continuously output from a sensor that generates pulses at different intervals when the rotating body rotates in the forward and reverse directions. In a rotating body rotation direction discriminating apparatus that inputs to a microcomputer and determines the rotating direction of the rotating body based on the edge input time, the microcomputer stores an input time of a falling edge of a pulse signal to be detected. A first register, a second register that stores the input time of the falling edge of the pulse signal immediately before the detection target pulse signal, and the input time of the rising edge of the pulse signal output from the sensor A third register for storing, a fourth register for storing the input time of the falling edge of the pulse signal output from the sensor, and in each register It is obtained by a edge interval measuring means for performing operations between definitive specified register.

  In addition, the control device for an internal combustion engine according to the present invention performs cylinder discrimination for a plurality of cylinders, and determines a rotation direction of a rotating body used in the internal combustion engine for each of the cylinders to be subjected to fuel injection or ignition. A control device for an internal combustion engine that can be identified by a microcomputer, wherein an edge input time of a pulse signal that is continuously output from a sensor that generates pulses at different intervals when the rotation direction of the rotating body is forward and reverse is detected by a microcomputer In the rotating body rotation direction discriminating apparatus for determining the rotation direction of the rotating body based on the edge input time, the microcomputer stores the first input of the falling edge of the pulse signal to be detected. A register, a second register for storing the input time of the falling edge of the pulse signal immediately before the pulse signal to be detected, and the sensor A third register for storing the input time of the rising edge of the pulse signal output from the sensor, a fourth register for storing the input time of the falling edge of the pulse signal output from the sensor, and a designation in each of the registers. And an inter-edge time measuring means for executing an operation between registers.

  According to the method and apparatus for determining the rotational direction of a rotating body according to the present invention, the sensor continuously generates pulses at different intervals depending on whether the rotational direction of the rotating body is normal or reverse. Since the edge interval of the output pulse signal can be measured correctly, it can be determined without making a mistake in determining whether the rotation direction of the rotating body is the normal rotation direction or the reverse rotation direction.

  According to the control apparatus for an internal combustion engine according to the present invention, it continues from the sensor that generates pulses having different intervals depending on whether the rotation direction of the rotating body used in the internal combustion engine is normal or reverse. The edge interval of the output pulse signal can be correctly measured, and by correctly recognizing the rotation direction of the rotating body, the count-up and count-down control of the cylinder identification counter can be correctly executed. For this reason, the rotation direction of the rotating body can be correctly recognized, and damage to the internal combustion engine due to erroneous ignition can be prevented.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a rotating body rotational direction determining method and apparatus according to the present invention, and an internal combustion engine control apparatus using the apparatus will be described below with reference to the drawings. The present invention is not limited to the embodiments.

Embodiment 1 FIG.
First, for convenience of explanation, a control system diagram in an internal combustion engine control apparatus to which the present invention is applied will be described. This control system is also described in Patent Document 2, and will be described with reference to this.

  FIG. 1 is a control system diagram of a control device for an internal combustion engine to which the present invention is applied. An internal combustion engine (hereinafter referred to as an engine) 1 includes a plurality of combustion chambers (cylinders) 2 (in FIG. 1, only one of them). And has a multi-cylinder engine. The air taken into the engine 1 is taken in from the input unit 4 of the air cleaner 3, passes through the intake air meter 5, passes through the throttle valve body 7 provided with the throttle valve 6 for controlling the suction flow rate, and enters the collector 8. Here, the throttle valve 6 is connected to a motor 9 that drives the throttle valve 6. The throttle valve 6 can be operated by driving the motor 9, and the intake air amount can be controlled by driving control of the motor 9. Yes.

  The intake air reaching the collector 8 is distributed to the intake pipes 10 connected to the combustion chambers 2 of the engine 1 and guided to the combustion chambers 2.

  Fuel such as gasoline is sucked and pressurized from a fuel tank 11 by a fuel pump 12, and a fuel injection valve 13 for each combustion chamber 2 and a variable fuel pressure regulator 14 for controlling the fuel pressure within a predetermined range are piped. Supplied to the fuel system. The fuel pressure is measured by a fuel pressure sensor (not shown).

  Fuel such as gasoline is directly injected into each combustion chamber 2 by the fuel injection valve 13. As a result, the engine 1 forms an in-cylinder injection engine.

  The air and the injected fuel that have flowed into the combustion chamber 2 are mixed in the combustion chamber 2, ignited by the spark plug 16 by the piezoelectric from the ignition coil 15, and burned. The gas combusted in the combustion chamber 2 of the engine 1, that is, the exhaust gas, is guided to the exhaust pipe 17 and released to the outside of the engine 1 through a catalyst (not shown).

  A signal indicating the intake air flow rate is output from the air flow meter 5, and the output signal is input to the ECU 18. A throttle sensor 19 for detecting the opening degree of the throttle valve 6 is attached to the throttle valve body 7, and an output signal of the throttle sensor 19 is input to the ECU 18.

  The ECU 18 inputs an output signal (crank angle sensor signal) of the crank angle sensor 20 and an output signal (cam angle sensor signal) of the cam angle sensor 21. The crank angle sensor 20 detects the rotation position (rotation angle) of the crankshaft 22 with an accuracy of at least about 1 to 10 °. The cam angle sensor 21 detects the rotation position (rotation angle) of the cam shaft 23 on the intake side.

  The A / F sensor 24 provided in the exhaust pipe 17 detects the actual operating air-fuel ratio from the exhaust gas component, and its output signal is also input to the ECU 18.

  A water temperature sensor 25 attached to the engine 1 detects the cooling water temperature of the engine 1, and its output signal is also input to the ECU 18. Further, the step sensor 26 detects the amount of depression of the accelerator pedal 27, and the output signal is also input to the ECU 18.

  The ECU 18 is of an electronic control type including a microcomputer, and controls the fuel injection timing, the injection flow rate (pulse width control of the fuel injection valve 13), the ignition timing, and the like by signals from the above-described sensors.

  In FIG. 1, 28 indicates a piston provided for each cylinder, 29 indicates a microcomputer built in the ECU 18, 30 indicates a power source, 31 indicates a relay switch, and 32 indicates an ignition switch. .

  The control system of the control apparatus for an internal combustion engine to which the present invention is applied is configured as described above. Next, a crank angle detection method and detection means for detecting the rotational position (rotation angle) of the crankshaft in this system. Will be described.

FIG. 2 is a system configuration diagram illustrating crank angle detection means of the control device for the internal combustion engine according to the first embodiment. FIG. 2 corresponds to FIG . 8 described in the prior art.
In FIG. 2, the register 200 in the microcomputer 29 provided in the ECU 18 includes a first register 200A, a second register 200B, a third register 200C, and a fourth register 200D.

  The first register 200A is a register for detecting and storing the falling edge of the target detection pulse, and the second register 200B is a register for detecting and storing the falling edge immediately before the falling edge. It is. The third register 200C is a register that detects and stores the rising edge of the pulse, and the fourth register 200D is a register that detects and stores the falling edge of the pulse. The detection signal of the crank angle sensor 20 is input from the first port 201 to the first and second registers 200A and 200B, and the detection signal of the crank angle sensor 20 from the second port 202 is input to the third and fourth registers 200C and 200D. A detection signal is input. That is, the second port 202 which is a rising / falling edge input port is a port used to know the state of the latest crank angle sensor signal, and the first port 201 which is a falling edge input port is This port is used to know the state of the crank angle sensor signal before one sampling.

  The crank angle detection means in the control apparatus for an internal combustion engine according to the first embodiment is configured as described above. Next, the operation will be described with reference to the time chart of FIG. 3 and the flowchart of FIG.

  The pulse output from the crank angle sensor 20 is input to a register 200 in a microcomputer 29 provided in the ECU 18. When the generated edge is the falling edge 300 shown in FIG. 3, the edge input time T1 is stored from the first port 201 to the second register 200B and from the second port 202 to the fourth register 200D. To do.

  If the generated edge is the rising edge 301 shown in FIG. 3, the edge input time T2 is stored from the second port 202 to the third register 200C, and then the S / W interrupt 302 is activated.

  In FIG. 3, for the next falling edge 303, the edge input time T3 is stored from the first port 201 to the first register 200A and from the second port 202 to the fourth register 200D.

  Next, after the occurrence of the interrupt by the S / W activated at the time 302 in FIG. 3, the falling edge input time stored in the fourth register 200D in step S400, as described in the flowchart in FIG. T1 is compared with the rising edge input time T2 stored in the third register 200C.

  As a result of the comparison in step S400, when the falling edge input time T1 of the fourth register 200D is a past time with respect to the rising edge input time T2 stored in the third register 200C (interrupt by S / W) When 302 is not prohibited by another event interrupt process), the process branches to step S401, and the value T1 stored in the fourth register 200D is subtracted from the value T2 stored in the third register 200C. Is the measurement time between edges.

  4, when the falling edge input time T1 of the fourth register 200D is a future time with respect to the rising edge input time T2 stored in the third register 200C (S / W The state in which the interrupt 302 due to another event is prohibited by interrupt processing due to another event) branches to step S402 and is stored in the second register 200B and the rising edge input time T2 stored in the third register 200C. The falling edge input time T1 (actually T3) is compared.

  As a result of the comparison in step S402, the rising edge input time T2 of the third register 200C is a future time with respect to the falling edge input time T1 (actually T3) stored in the second register 200B. In this case, the process branches to step S403, and is obtained by subtracting the falling edge input time T1 (actually T3) stored in the first register 200A from the rising edge input time T2 stored in the third register 200C. The measurement time between edges.

  When the rising edge input time T2 stored in the third register 200C is a past time with respect to the falling edge input time T1 stored in the second register 200B in step S402 in FIG. The process branches to step S404, and a value obtained by subtracting the falling edge input time T1 stored in the second register 200B from the rising edge input time T2 stored in the third register 200C is set as a measurement time between edges.

  As described above, according to the control apparatus for an internal combustion engine according to the first embodiment, it is erroneously determined whether the engine rotation direction is normal rotation or reverse rotation by accurately determining the rotation direction of the crankshaft. Nothing will happen. Accordingly, there is no possibility of counting down where the cylinder identification counter should be counted up, and there is no possibility of damaging the internal combustion engine by making an erroneous ignition target cylinder and causing erroneous ignition.

  In the first embodiment, the case where the present invention is applied to the determination of the rotation direction of the crankshaft has been described as an example. However, the present invention may be applied to the determination of the rotation direction of the camshaft. You may apply to discrimination | determination of the rotation direction of.

  In addition, the present invention is not limited to the determination of the rotation direction of a rotating body used in an internal combustion engine such as a crankshaft or a camshaft, but is different depending on whether the rotation direction of the rotating body is normal or reverse. Using the pulse signal continuously output from the sensor that generates the pulse, the time between edges of the short period of the pulse signal is measured to determine the rotation direction of the rotating body. Applicable.

1 is a control system diagram of a control device for an internal combustion engine to which the present invention is applied. FIG. 1 is a system configuration diagram illustrating crank angle detection means of a control device for an internal combustion engine according to Embodiment 1 of the present invention. FIG. It is a time chart explaining operation | movement of the crank angle detection means in the control apparatus of the internal combustion engine which concerns on Embodiment 1 of this invention. 3 is a flowchart illustrating the operation of crank angle detection means in the control device for an internal combustion engine according to the first embodiment of the present invention. It is a figure which shows the output signal waveform of the crank angle sensor with a reverse rotation detection function which has a pulse generation function of the space | interval different at the time of forward rotation and reverse rotation. It is a figure which shows count value a which counts periodically between 720 degrees CA (crank angle) from the compression top dead center of the cylinder of an internal combustion engine. It is a figure explaining the rotation identification method of the normal rotation / reverse rotation direction of a crankshaft. It is a system block diagram explaining the crank angle detection means in the control apparatus of the conventional internal combustion engine. It is a time chart explaining operation | movement of the crank angle detection means in the control apparatus of the conventional internal combustion engine. It is a flowchart explaining operation | movement of the crank angle detection means in the control apparatus of the conventional internal combustion engine. It is a time chart explaining the fault of operation | movement of the crank angle detection means in the control apparatus of the conventional internal combustion engine.

1 Internal combustion engine
2 Combustion chamber (cylinder)
DESCRIPTION OF SYMBOLS 3 Air cleaner 4 Input part 5 Intake air meter 6 Throttle valve 7 Throttle valve body 8 Collector 9 Motor 10 Intake pipe 11 Fuel tank 12 Fuel pump 13 Fuel injection valve 14 Variable fuel pressure regulator 15 Ignition coil 16 Spark plug 17 Exhaust pipe 18, 91 ECU
19 Throttle sensors 20, 90 Crank angle sensor 21 Cam angle sensor 22 Crankshaft 23 Camshaft 24 A / F sensor 25 Water temperature sensor 26 Tread amount sensor 27 Accelerator pedal 28 Piston 29, 92 Microcomputer 30 Power supply 31 Relay switch 32 Ignition switch 93 , 200 Register 93A, 200A First register 93B, 200B Second register 200C Third register 200D Fourth register 201 First port 202 Second port

Claims (3)

A rotating direction determination method of the rotating body to determine the direction of rotation of the rotating body, the pulse direction of rotation of the rotating body is continuously output from the sensor for generating a pulse of a different spacing between the reverse rotation and forward rotation enter the edges of the signal input time in the microcomputer, in the rotational direction determination method of the rotating body to determine the rotation direction of the rotary member by the edge input time,
The input time of the falling edge of the pulse signal targeted for detection is stored in the first register of the microcomputer, and the input time of the falling edge of the pulse signal immediately before the pulse signal targeted for detection is stored in the microcomputer. Stored in the second register of the computer,
Storing the input time of the rising edge of the pulse signal output from the sensor in the third register of the microcomputer, and storing the input time of the falling edge in the fourth register of the microcomputer;
When the edge input time stored in the fourth register is earlier than the input time stored in the third register, the input time stored in the fourth register is subtracted from the input time stored in the third register. Is the measurement time between edges,
If the edge input time stored in the fourth register is later than the input time stored in the third register, the input time stored in the third register is compared with the input time stored in the second register; If the input time stored in the third register is earlier than the input time stored in the second register, an edge obtained by subtracting the input time stored in the second register from the input time stored in the third register If the input time stored in the third register is later than the input time stored in the second register, the input time stored in the first register from the input time stored in the third register. A method of discriminating the rotational direction of a rotating body using a subtracted value as a measurement time between edges . A rotation direction discriminating device for a rotating body that discriminates a rotating direction of a rotating body, wherein the rotation direction of the rotating body is continuously output from a sensor that generates pulses at different intervals between forward rotation and reverse rotation. In a rotation direction discriminating device for a rotating body that inputs an edge input time of a signal to a microcomputer and discriminates the rotating direction of the rotating body based on the edge input time,
The microcomputer includes a first register that stores an input time of a falling edge of a pulse signal to be detected;
A second register for storing the input time of the falling edge of the pulse signal immediately before the pulse signal to be detected;
A third register for storing the input time of the rising edge of the pulse signal output from the sensor;
A fourth register for storing the input time of the falling edge of the pulse signal output from the sensor;
A rotation direction discriminating device for a rotating body, comprising: an inter-edge time measuring means for executing an operation between designated registers in each register . In a control device for an internal combustion engine that performs cylinder discrimination for a plurality of cylinders and identifies a cylinder in which fuel injection or ignition is to be performed by determining the rotation direction of a rotating body used in the internal combustion engine,
A control apparatus for an internal combustion engine, wherein the rotation direction of the rotating body is determined by the rotation direction determining apparatus of the rotating body according to claim 2.

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