JP6003869B2 - Engine control device - Google Patents

Description

  The present invention relates to an engine control device.

  In a vehicle engine control apparatus, a crank that is a rotational position of a crankshaft is based on a rotation signal (generally a crank signal output from a crank sensor) that generates a pulse edge every time the crankshaft of the engine rotates by a predetermined angle. The position (so-called crank angle) is grasped. And based on the grasped crank position, engine control (fuel injection, ignition, etc.) is performed.

  Specifically, the pulse edge interval in the crank signal is measured, a multiplied clock having a period obtained by reducing the measured value to a predetermined multiplication factor is generated, and the count value of the angle counter representing the crank position is Counts up using a multiplied clock. The count value of the angle counter becomes an angle signal representing the crank position with a resolution smaller than the predetermined angle (the predetermined angle / multiplier resolution). For this reason, fuel injection, ignition, etc. are implemented based on the value of the angle signal (count value of the angle counter). For example, ignition and fuel injection are performed when the value of the angle signal matches a set value corresponding to the target crank position (see, for example, Patent Document 1).

  In the conventional engine control device, the angle signal is generated using all the pulse edges in the crank signal. Further, in the crank signal, there is a reference position portion in which the intervals of the pulse edges are unequal in the middle of the row of pulse edges. As typical examples of the reference position portion, there are known a missing tooth portion where a pulse edge does not occur a predetermined number of times and a case where an additional pulse edge is inserted (for example, see Patent Document 1).

JP 2001-200747 A

  When the crank signal has the reference position portion, the intervals between the pulse edges in the crank signal are not all the same, and therefore the following specific pulse edge exists as the pulse edge.

  The specific pulse edge does not occur at a crank position that is advanced by a predetermined angle from the top dead center position of a predetermined cylinder among a plurality of cylinders of the engine, but is a specific cylinder edge different from the predetermined cylinder. This is a pulse edge that occurs at a crank position that is advanced by a predetermined angle from the top dead center position.

  When viewed for each cylinder, there are cylinders in which a pulse edge is generated in the crank signal and cylinders in which no pulse edge is generated at the crank position having the same relative angle from the top dead center position to the advanced angle side.

  Here, the specific cylinder is referred to as “cylinder with specific pulse”, and the predetermined cylinder is referred to as “cylinder without specific pulse”. Also, the crank position range corresponding to the two pulse edges immediately before and after the specific pulse edge is called a “specific range”, and specified based on the top dead center position of the cylinder without the specific pulse. A crank position range that has the same positional relationship as the relative positional relationship between the top dead center position of the cylinder with pulse and the specific range is referred to as a “specific equivalent range”.

The specific pulse edge is generated in the specific range, whereas no pulse edge is generated in the specific equivalent range.
For this reason, in the conventional engine control device that generates the angle signal using all the pulse edges in the crank signal, there is a difference in how the angle signal is increased between the specific range and the specific equivalent range. In a specific range, the degree of increase in the angle signal is updated based on a specific pulse edge occurring in the range, whereas in the specific equivalent range, no pulse edge is generated, so the degree of increase in the angle signal Is not updated.

For this reason, the control operation based on the angle signal varies between the cylinder with the specific pulse and the cylinder without the specific pulse.
Accordingly, an object of the present invention is to make it possible to suppress variations in control operations among cylinders in an engine control apparatus.

  The engine control apparatus according to the first aspect of the present invention includes angle signal generation means. The angle signal generation means receives a rotation signal that generates a pulse edge every time the crankshaft of the engine rotates by a predetermined angle, and generates an angle signal that represents the crank position that is the rotation position of the crankshaft with a resolution smaller than the predetermined angle. And based on the rotation signal. The engine control apparatus controls the engine based on the angle signal generated by the angle signal generation means.

Here, the rotation signal has a reference position portion in which the intervals between the pulse edges are unequal in the middle of the pulse edge sequence.
In this engine control device, the angle signal generation means is a specific pulse edge of the pulse edges in the rotation signal, and is predetermined from a top dead center position of a predetermined cylinder among a plurality of cylinders of the engine. It does not occur at a crank position that is advanced by an angle, but a specific pulse edge that is generated at a crank position that is advanced by a predetermined angle from the top dead center position of a specific cylinder different from the predetermined cylinder is not used. In addition, the angle signal is generated.

  For this reason, the angle signal generation means generates an angle signal without using a specific pulse edge in the specific range described above. Therefore, it is possible to avoid a difference in how the angle signal is increased between the specific range and the specific equivalent range described above. As a result, the specific cylinder (cylinder with specific pulse) and the predetermined range can be avoided. It is possible to prevent the control operation based on the angle signal from fluctuating between the cylinders (cylinders without a specific pulse).

  In addition, the code | symbol in the parenthesis described in the claim shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The technical scope of this invention is limited is not.

It is a block diagram of the engine control apparatus (ECU) of 1st Embodiment. It is a time chart explaining an effect | action of a crank signal and 1st Embodiment. It is a block diagram of a hard crank. It is a time chart explaining control of ignition. It is a flowchart showing the switching process of 1st Embodiment. It is a time chart explaining a comparative example. It is a flowchart showing the switching process of 2nd Embodiment. It is explanatory drawing explaining a 1st modification. It is explanatory drawing explaining a 2nd modification.

  An engine control apparatus (hereinafter referred to as ECU) according to an embodiment to which the present invention is applied will be described. Note that the ECU of the present embodiment controls, for example, a four-cylinder gasoline engine mounted on the vehicle.

[First Embodiment]
As shown in FIG. 1, the ECU 1 includes a microcomputer (microcomputer) 10 and an input / output circuit 20.

  The microcomputer 10 includes a CPU 11, a ROM 12, a RAM 13, an A / D converter (ADC) 14, an input / output interface (I / O) 15, a timer module 16, and the like. Are connected so that they can exchange data.

  The input / output circuit 20 inputs a signal from a sensor, a switch, or the like input from the outside of the ECU 1 to the microcomputer 10 and outputs a drive signal to the injector (fuel injection valve) according to the signal from the microcomputer 10. The input / output circuit 20 amplifies and outputs the ignition pulse for each cylinder output from the microcomputer 10 to the ignition device for each cylinder.

  The CPU 11 of the microcomputer 10 takes in signals from sensors, switches, and the like through the input / output circuit 20 and the input / output interface 15 and performs various calculations based on these signals. The CPU 11 drives and controls the injector and the ignition device via the input / output interface 15 and the input / output circuit 20 based on the calculation result. The operation of the CPU 11 is realized by the CPU 11 executing a program in the ROM 12.

The signals input to the ECU 1 include a crank signal from the crank sensor 21 and a cam signal from the cam sensor 23.
As shown in FIG. 2, the crank signal is a signal that generates a pulse edge every time the crankshaft of the engine rotates by a predetermined angle (10 ° in this example). FIG. 2 shows a crank signal corresponding to 720 ° CA (CA is an abbreviation of “crank angle”) that is one cycle of the engine.

  A pulse edge (hereinafter, also referred to as a crank edge) in the crank signal at one predetermined angle is one or both of a falling edge and a rising edge, which is, for example, a falling edge in the present embodiment. For convenience, it is represented by a vertical line. This expression is the same in other drawings. The crank sensor 21 generates a pulse edge by detecting a plurality of teeth formed on the outer periphery of the rotor that rotates together with the crankshaft of the engine.

  In addition, the crank signal has a reference position portion having an unequal interval between pulse edges (hereinafter also referred to as a crank edge interval) in the middle of a row of pulse edges (crank edges). In the present embodiment, the reference position portion has a crank edge interval of “N + 1” times that of other crank edge intervals because the crank edge does not occur N times (N is an integer equal to or greater than 1 and is 2 in this example). This is a missing tooth portion Pa that becomes longer (in this example, three times longer).

  The crank signal in the present embodiment has a configuration in which two pulses are missed every 34 pulses, and a period corresponding to 30 ° CA from which the two pulses are missing is the missing tooth portion Pa. For this reason, the missing tooth portion Pa appears at two locations at 720 ° CA (appears every 360 ° CA).

  In the present embodiment, the crank position at the end timing of the missing tooth portion Pa (specifically, the crank position corresponding to the end of the missing tooth portion Pa is generated, hereinafter referred to as the missing tooth portion end position). Are the TDC positions (TDC is an abbreviation of top dead center) for the second cylinder # 2 and the third cylinder # 3 of the engine. For this reason, the missing tooth portion Pa appears in the period from BTDC 30 ° CA to TDC of the second cylinder # 2 and in the period from BTDC 30 ° CA to TDC of the third cylinder # 3. BTDC is an abbreviation before top dead center. For example, BTDC 30 ° CA is a crank position 30 ° CA before the TDC position.

  Such a crank signal is input to the microcomputer 10 via the input / output circuit 20, and is input to the hard crank 30 of the timer module 16 via the switching circuit 40 (see FIG. 3) described later.

  On the other hand, although not shown, the cam signal is a signal that generates a pulse edge at a specific crank position in one cycle of the engine, for example. The cam sensor 23 generates a pulse edge by detecting teeth formed on the outer periphery of the rotor that rotates together with the cam shaft of the engine.

  The cam signal is also input to the microcomputer 10 via the input / output circuit 20. In the microcomputer 10, the CPU 11 performs cylinder discrimination by a well-known method based on the combination of the crank signal and the cam signal. Hereinafter, the pulse edge in the cam signal is referred to as a cam edge. In this example, the cam edge occurs once in one cycle of the engine.

  As a specific example, for example, the CPU 11 detects a missing tooth portion Pa in a crank signal based on the crank edge interval, and detects a missing tooth portion Pa until a predetermined number of crank edges are generated. Then, it is determined whether or not a cam edge has occurred in the cam signal. If the cam edge occurs, the missing tooth portion Pa detected this time is the missing tooth portion Pa corresponding to the TDC of, for example, the third cylinder # 3 of the second cylinder # 2 and the third cylinder # 3. If it is determined that there is no cam edge, it is determined that the missing tooth portion Pa detected this time is the missing tooth portion Pa corresponding to the TDC of the second cylinder # 2, for example. Note that the CPU 11 may detect the generation of the missing tooth portion Pa based on a missing tooth detection signal output from the hard crank 30 described later.

  Then, the CPU 11 specifies the current crank position by such cylinder discrimination, and sets a value corresponding to the specified crank position to the crank counter on software representing the crank position for every 10 ° CA in one cycle of the engine. set. Thereafter, the CPU 11 increments the crank counter by 1 each time a crank edge occurs, and adds 3 to the value of the crank counter at the end timing of the missing tooth portion Pa. Then, the CPU 11 returns the value of the crank counter to 0 when the value of the crank counter reaches the maximum value corresponding to 720 ° CA.

  For this reason, the value of the crank counter is lap rounded between 0 and a maximum value corresponding to 720 ° CA (71 in this example). Therefore, the crank position at every 10 ° CA in one cycle can be known from the value of the crank counter.

  Further, the microcomputer 10 detects an angle signal representing a crank position with a resolution smaller than 10 ° CA, which is a crank edge generation interval, and a missing tooth portion Pa by a hard crank 30 as a processing unit for processing a crank signal. A missing tooth detection signal indicating this is generated and output.

  As shown in FIG. 3, the hard crank 30 includes a frequency dividing circuit 31, an edge time measurement counter 32, an edge time storage register 33, a multiplication counter 34, a guard counter 35, a missing tooth determination counter 36, A reference counter 37 and an angle counter 38 are provided.

  A clock Pφ having a constant frequency (for example, 20 MHz) output from a prescaler (not shown) in the microcomputer 10 is frequency-divided by the frequency dividing circuit 31, and the clock after frequency division (hereinafter referred to as frequency-divided clock) is an edge time. It is sent to the measurement counter 32 and the multiplication counter 34. The clock Pφ is sent to the angle counter 38 as it is.

  On the other hand, the microcomputer 10 includes a switching circuit 40 that switches whether to input a crank signal to the hard crank 30 according to a control signal from the CPU 11. In the hard crank 30, the crank signal input via the switching circuit 40 is sent to the edge time measurement counter 32, the guard counter 35, and the missing tooth determination counter 36.

  The edge time measurement counter 32 is a counter that measures the crank edge interval using a frequency-divided clock from the frequency divider circuit 31. That is, the edge time measurement counter 32 measures the number of frequency-divided clocks generated between the occurrence of a crank edge and the occurrence of the next crank edge as the crank edge interval. Note that the period of the divided clock is sufficiently smaller than the minimum value of the crank edge interval.

  Each time the edge time measurement counter 32 completes the measurement of the crank edge interval, the latest measurement value is reduced to a predetermined multiplication factor (n) and stored in the edge time storage register 33. A value stored in the edge time storage register 33 (hereinafter referred to as a multiplication cycle value) is transferred to the multiplication counter 34. In the present embodiment, the resolution of the angle signal to be generated is, for example, 1 ° CA, and therefore the multiplication factor n is set to 10.

  The multiplication counter 34 is a counter that counts down from the multiplication cycle value by the divided clock. Each time the count value becomes 0, the multiplication counter 34 outputs a multiplication clock and the multiplication cycle value in the edge time storage register 33 is reloaded (initially). Reset as value). For this reason, the multiplication counter 34 is based on the current crank edge interval measured by the edge time measurement counter 32, and the cycle is 1 / n of the current crank edge interval until the next crank edge is generated. Generate and output a clock.

The reference counter 37 counts up with a multiplied clock.
As shown in FIG. 2, the guard counter 35 counts up with a crank edge. Then, when the crank edge is input, the guard counter 35 transfers a value obtained by multiplying the value immediately before the count-up by a multiplication number (n) to the reference counter 37 and sets it to the reference counter 37. The value set in the reference counter 37 is an expected value of the values of the reference counter 37 and the angle counter 38 when the crank edge occurs.

  Further, a value obtained by multiplying the value of the guard counter 35 by a multiplication number (n) is given to the reference counter 37 as a gart value. The count value of the reference counter 37 cannot exceed the guard value. The guard value is an expected value of the values of the reference counter 37 and the angle counter 38 when the next crank edge occurs.

  The angle counter 38 is a counter that counts up by the clock Pφ, but counts up only when its count value is smaller than the count value of the reference counter 37.

For this reason, the angle counter 38 operates as in the following (1) to (3) (see FIG. 2).
(1) Count operation (in this example, count-up) is performed at a cycle of a multiplied clock based on the latest crank edge interval.

  (2) When the crank edge is generated, if the count value is smaller than the expected value set from the guard counter 35 to the reference counter 37, the count value is counted up to the expected value by the clock Pφ at the highest speed. For this reason, when the rotation speed of the crankshaft increases (that is, during acceleration when the crank edge interval becomes shorter than the previous time), the count value of the angle counter 38 is prevented from becoming insufficient from the expected value. The

  (3) If the count value reaches the guard value (n times the guard counter value) before the next crank edge occurs, the count-up is stopped. For this reason, when the rotational speed of the crankshaft decreases (that is, during deceleration at which the crank edge interval becomes longer than the previous time), an excessive count-up of the angle counter 38 is prevented.

  In the hard crank 30, an angle signal is generated in synchronization with the count up of the angle counter 38. In other words, the angle counter 38 is a counter whose count value represents the crank position with a resolution of “10 ° CA / multiplier” (in this example, a resolution of 1 ° CA). The bit signal becomes an angle signal.

  The angle counter 38 is counted up by a clock Pφ whose period is sufficiently smaller than the multiplied clock so that the count value thereof is the same as the count value of the reference counter 37. For this reason, the angle counter 38 is also basically counted up by the multiplied clock similarly to the reference counter 37, but the count-up timing is after the value of the reference counter 37 is changed by the multiplied clock. The next clock Pφ is output. That is, the angle counter 38 synchronizes the change timing of the count value with the clock Pφ with respect to the reference counter 37. For this reason, if there is no need to synchronize the change timing of the value of the angle signal with the clock Pφ, the signal representing the count value of the reference counter 37 can be an angle signal.

  Further, in the hard crank 30, the missing tooth determination counter 36 is cleared to 0 by the crank edge and is counted up by the multiplied clock. Then, the missing tooth determination counter 36 outputs a missing tooth detection signal when its count value reaches a predetermined missing tooth determination value. The missing tooth determination value is a value obtained by multiplying the count value between the previous crank edges by a predetermined number of times (for example, 2.5 times).

  For this reason, when the missing tooth portion Pa occurs in the crank signal and the crank edge is not input for a certain time or more, the count value of the missing tooth determination counter 36 reaches the missing tooth determination value, and the missing tooth detection signal is output. .

  The missing tooth detection signal is used as an interrupt signal in the microcomputer 10, for example. Further, the missing tooth determination counter 36 outputs a missing tooth detection signal at the crank edge generation timing (that is, the missing tooth end position timing) after its own count value becomes equal to the missing tooth determination value, for example. To do. Therefore, in this embodiment, a missing tooth detection signal is output at each TDC position (see FIG. 2) of the second cylinder # 2 and the third cylinder # 3.

  On the other hand, in the microcomputer 10, for example, the CPU 11 detects the guard counter 35 at the timing when the crank edge is generated a predetermined number of times from the timing at which the missing tooth determination counter 36 outputs the missing tooth detection signal (timing at the missing tooth end position). Initial values are set in the reference counter 37 and the angle counter 38.

  In the present embodiment, as shown in FIG. 2, the CPU 11 sets 0 as an initial value to the reference counter 37 and the angle counter 38 at the timing when the crank edge occurs 12 times from the timing of the missing tooth end position. At the same time, 1 is set as the initial value in the guard counter 35 in order to set the guard value (that is, the initial value of the guard value) until the next crank edge occurs to the multiplication factor (n). Note that the initialization (returning the initial value) of the counters 35, 37, and 38 may be performed by hardware different from the CPU 11. Further, it may be performed once per engine cycle (every 720 ° CA).

By the way, in the missing tooth portion Pa, two crank edges are missed, so the crank edge interval becomes three times the normal.
For this reason, if no treatment is performed at the missing tooth end position, the edge time storage register 33 stores a value that is three times the normal value (that is, a value obtained by measuring a time corresponding to 30 ° CA by a multiplication factor n). As a result, the cycle of the multiplication clock output from the multiplication counter 34 is three times the normal value.

  In addition, no action is taken at the crank position at the start timing of the missing tooth portion Pa (specifically, the crank position corresponding to the start of the missing tooth portion Pa, hereinafter referred to as the missing tooth portion starting position). Otherwise, the guard value in the period of the missing tooth portion Pa increases only by a value (= multiplication number n) corresponding to 10 ° CA from the previous guard value, as usual. For this reason, during the period of the missing tooth portion Pa, each value of the reference counter 37 and the angle counter 38 should increase by a value corresponding to 30 ° CA if it is true, but only increases by a value corresponding to 10 ° CA. No longer.

For this reason, the CPU 11 performs the following correction processes (A) and (B).
(A) If the CPU 11 determines that the crank edge generated this time is the crank edge at the missing tooth start position based on the value of the crank counter described above, the CPU 11 adds 2 to the value of the guard counter 35. By this processing, the guard value in the period of the missing tooth portion Pa becomes a value increased by a value (= multiplication number n × 3) corresponding to 30 ° CA from the previous guard value (see FIG. 2).

  (B) If the CPU 11 determines that the currently generated crank edge is the crank edge at the missing tooth end position based on the value of the above-mentioned crank counter, the CPU 11 calculates the measured value by the current edge time measuring counter 32 as 1 / 3 and the value that is reduced to 1/3 is stored in the edge time storage register 33. In other words, the multiplication number for generating the multiplied clock in the period from the missing tooth end position to the next crank edge is set to three times the normal value (= n).

As a result of such correction processing, the value of the angle counter 38 increases with the same inclination as in the period other than the missing tooth portion Pa as shown in FIG. 2 even during the missing tooth portion Pa period.
Further, the microcomputer 10 performs fuel injection and ignition for each cylinder using the value of the angle signal generated by the hard crank 30 (value of the angle counter 38).

  Here, the ignition control for the cylinder will be described with reference to FIG. In FIG. 4, the case where the third cylinder # 3 is ignited is shown as an example, but the same applies to the other cylinders.

As shown in FIG. 4, in this embodiment, the timing of BTDC 60 ° CA of the cylinder is the ignition pulse setting timing for the cylinder.
When the CPU 11 detects the timing of BTDC 60 ° CA of the cylinder based on the value of the crank counter or the angle counter 38, the CPU 11 performs the following processing. First, the CPU 11 calculates, as information indicating the ignition timing, an off-angle OA indicating how much the ignition pulse to the ignition device is changed from high to low at the timing of the crank angle before the TDC. In this example, the change timing (falling timing) of the ignition pulse from high to low is the ignition timing by the ignition device. In the present embodiment, the ignition timing is set between BTDC 30 ° CA and the TDC position of each cylinder.

  Then, the CPU 11 calculates a differential angle (= SA−OA) that is a value obtained by subtracting the off-angle OA from the set angle SA that is the crank angle from the ignition pulse setting timing to TDC (60 ° CA in this example). .

  Further, the CPU 11 sets an internal timer for making the ignition pulse high so that the ignition pulse becomes high at a timing before the ignition timing (in the example of FIG. 4, the timing of BTDC 30 ° CA).

  Further, the CPU 11 sets a value obtained by adding the difference angle (= SA−OA) to the value of the angle counter 38 at the timing of BTDC 60 ° CA in the compare register. In the microcomputer 10, when the value of the angle signal (value of the angle counter 38) matches the value of the compare register, the output level of the ignition pulse changes from high to low, and ignition is performed by the ignition device at that timing. . Thus, ignition of each cylinder is performed based on the angle signal.

  Next, a switching process performed by the CPU 11 in order to appropriately generate an angle signal in the hard crank 30 will be described with reference to FIG. This switching process includes the correction processes (A) and (B), and is executed each time a crank edge occurs.

  In the following description, the missing tooth start equivalent position is the TDC position of cylinders # 1 and # 4 in which the missing tooth Pa does not appear on the advance side of the TDC position among the cylinders # 1 to # 4. The crank position is in the same positional relationship as the relative positional relationship between the TDC positions of the cylinders # 2 and # 3 and the missing tooth start position as a reference. In the present embodiment, since the position of BTDC 30 ° CA of cylinders # 2 and # 3 is the missing tooth start position, the position of BTDC 30 ° CA of cylinders # 1 and # 4 is the position corresponding to the missing tooth start. .

  Similarly, the missing tooth end equivalent position is the same positional relationship as the relative positional relationship between the TDC positions of cylinders # 2 and # 3 and the missing tooth end position with reference to the TDC positions of cylinders # 1 and # 4. Is the crank position. In the present embodiment, since the TDC positions of the cylinders # 2 and # 3 are the missing tooth portion end positions, the TDC positions of the cylinders # 1 and # 4 are positions corresponding to the missing tooth portion ends.

  Further, the position one tooth before the position corresponding to the end of the missing tooth portion is the crank position corresponding to the crank edge one position before the position corresponding to the end of the missing tooth portion. In this embodiment, the positions of the cylinders # 1 and # 4 The position is BTDC 10 ° CA.

  As shown in FIG. 5, when starting the switching process, the CPU 11 first determines in S110 whether or not the current crank position is a missing tooth start equivalent position based on the value of the crank counter described above. If the current crank position is the position corresponding to the missing tooth start, the process proceeds to S120.

  Then, in S120, the CPU 11 controls the switching circuit 40 (see FIG. 3) to prohibit the input of the crank signal to the hard crank 30, and then proceeds to S150. Note that the crank signal input prohibition state in S120 is continued until it is permitted in S140, which will be described later.

  If the CPU 11 determines in S110 that the current crank position is not the missing tooth start equivalent position, the process proceeds to S130. In S130, the CPU 11 determines whether or not the current crank position is a position one tooth before the missing tooth end equivalent position based on the value of the crank counter described above, and the current crank position is the missing tooth. If it is a position one tooth before the part end equivalent position, the process proceeds to S140.

  Then, in S140, the CPU 11 controls the switching circuit 40 to permit the input of the crank signal to the hard crank 30 (in other words, cancel the prohibition), and then proceeds to S150.

  If the CPU 11 determines in S130 that the current crank position is not the position one tooth before the missing tooth end equivalent position (that is, the current crank position is the missing tooth start equivalent position and the missing tooth position). If it is not one of the positions corresponding to the end of the tooth and the position before one tooth), the process directly proceeds to S150.

  In S150, the CPU 11 determines whether or not the current crank position is either the missing tooth start position or the missing tooth start corresponding position based on the value of the aforementioned crank counter, and the current crank position is determined. If it is either the missing tooth start position or the missing tooth start equivalent position, the process proceeds to S160.

  In S160, the CPU 11 adds 2 to the value of the guard counter 35, and then ends the switching process. The process of S160 performed when the crank position is the missing tooth start position is the correction process (A) described above.

If the CPU 11 determines in S150 that the current crank position is neither the missing tooth start position or the missing tooth start corresponding position, the process proceeds to S170.
In S170, the CPU 11 determines whether the current crank position is either the missing tooth end position or the missing tooth end corresponding position based on the value of the crank counter described above. If the crank position is either the missing tooth end position or the missing tooth end equivalent position, the process proceeds to S180.

  In S180, the CPU 11 reduces the current measurement value by the edge time measurement counter 32 to 1/3, and stores the value that is reduced to 1/3 in the edge time storage register 33. Thereafter, the switching process is terminated. The process of S180 performed when the crank position is the missing tooth end position is the correction process (B) described above.

  On the other hand, if it is determined in S170 that the current crank position is neither the missing tooth end position or the missing tooth end equivalent position, the CPU 11 ends the switching process.

  In such switching processing, among the crank edges, the crank edges marked with “x” in FIG. 2 are prohibited from being input to the hard crank 30 by the processing of S110 to S140.

  Two crank edges that are prohibited from being input to the hard crank 30 are generated in the range of the crank position from the missing tooth start equivalent position to the missing tooth end equivalent position (hereinafter referred to as the missing tooth equivalent range Pb). Are crank edges (hereinafter referred to as specific crank edges) generated at BTDC 20 ° CA and BTDC 10 ° CA of cylinders # 1 and # 4. That is, the specific crank generated in the missing tooth equivalent range Pb having the same positional relationship as the relative positional relationship between the TDC positions of the cylinders # 2 and # 3 and the missing tooth portion Pa as viewed from the TDC positions of the cylinders # 1 and # 4. The edge is not input to the hard crank 30.

  For this reason, in the switching process, even when the position corresponding to the missing tooth portion start position is reached, the process of S160 (correction process (A)) is performed in the same manner as when the missing tooth portion start position is reached. When the end equivalent position is reached, the process of S180 ((B) correction process) is performed in the same manner as when the missing tooth end position is reached.

  Therefore, as shown in FIG. 2, even in the period of the missing tooth portion equivalent range Pb from BTDC 30 ° CA to TDC of cylinders # 1 and # 4, the angle of 1 ° CA resolution is the same rule as the period of missing tooth portion Pa. A signal is generated (in other words, the value of the angle counter 38 is updated).

  As described above, the microcomputer 10 generates the angle signal without intentionally using the specific crank edge generated in the missing tooth portion equivalent range Pb among the crank edges. The reason will be described.

  First, if the switching process of FIG. 5 is changed so that the processes of S110 to S140 are not performed (that is, the input of the crank signal to the hard crank 30 is not prohibited), the process of S160 is It is assumed that the processing is performed only at the missing tooth portion start position, and the process of S180 is performed only at the missing tooth portion end position.

In that case, as shown in FIG. 6, the angle signal is generated using all the crank edges (that is, using the specific crank edge).
Then, in the period of the missing tooth portion Pa, the inclination (that is, the period of the multiplied clock) by which the angle counter 38 is counted up is not updated with a value based on the immediately preceding crank edge interval, whereas it corresponds to the missing tooth portion. In the period Pb, the inclination at which the angle counter 38 is counted up is updated every 10 ° CA due to the occurrence of a specific crank edge. Therefore, the period of the missing tooth portion Pa and the period of the missing tooth portion equivalent range Pb are in the same relative position as seen from the TDC position of each cylinder, but there is a difference in how the angle signal is increased. .

  More specifically, the rotational speed of the crankshaft fluctuates even if the engine speed is considered to be constant. For example, the rotational speed of the crankshaft tends to increase when the crank position passes the TDC position of the cylinder where ignition is performed, and then decreases as the crank position approaches the TDC position of the cylinder where ignition is performed next. . 2, 4, and 6, this is the reason why the crank edge interval for every 10 ° CA is not constant.

  Therefore, in the period of the missing tooth equivalent range Pb, the period of the multiplied clock until the first specific crank edge is generated is “T1”, and the second specific crank edge is generated after the first specific crank edge is generated. If the period of the multiplied clock until the occurrence of the second crankshaft is “T2”, and the period of the multiplied clock from the occurrence of the second specific crank edge to the occurrence of the next crank edge is “T3”, then T1 Is considered to be the same as the period of the multiplied clock in the period of the missing tooth portion Pa, but T2 and T3 are considered to be larger than T1. For example, it is considered that the magnitude relationship is “T1 <T2 <T3”.

  For this reason, between the period of the missing tooth portion Pa and the period of the missing tooth portion equivalent range Pb, the period of the missing tooth portion equivalent range Pb has a larger period of the multiplied clock, and the count up of the angle counter 38 progresses later. It will be.

  Then, when the ignition timing is set by the method described with reference to FIG. 4, as shown in FIG. 6, the period of the missing tooth portion equivalent range Pb is equal to the period of the missing tooth portion Pa and the period of the missing tooth portion equivalent range Pb. However, the actual ignition timing is delayed (closer to the TDC position). In the example of FIG. 6, the ignition timings of cylinders # 1 and # 4 are later than the ignition timings of cylinders # 2 and # 3. This means that the actual ignition timing varies among the cylinders even if the set value of the ignition timing (the above-mentioned off-angle OA) is the same for all the cylinders.

  On the other hand, in the ECU 1 of the present embodiment, the microcomputer 10 does not use the two specific crank edges that occur during the period of the missing tooth equivalent range Pb and uses the same rule as the period of the missing tooth Pa. To generate an angle signal. For this reason, as shown in FIG. 2, the angle signal increases in the same way during the period of the missing tooth portion Pa and the period of the missing tooth portion equivalent range Pb. Therefore, as shown in the stage of “ignition pulse” in FIG. 2, the ignition timing of each cylinder can be matched.

  In the stage of “ignition pulse” in FIG. 2, the pulse indicated by the dotted line is the overlapped ignition pulse of cylinders # 1 and # 4 in FIG. 6 for comparison. Here, the effect has been described by taking the ignition control as an example, but the same effect (that is, the cylinder control) is also applied to other control (for example, control of fuel injection) that uses an angle signal to synchronize with the crank position. The effect that the variation of the control operation between the two can be suppressed can be expected.

  Further, the ECU 1 according to the present embodiment has an advantage that versatility is high because the crank signal for generating the angle signal is a signal having the missing tooth portion Pa as a reference position portion for cylinder discrimination.

  Further, the CPU 11 of the microcomputer 10 determines that the specific crank edge generated in the missing tooth equivalent range Pb among the crank edges is input to the hard crank 30 (and thus the edge time measurement counter 32). It is prohibited by controlling. Furthermore, the CPU 11 detects when a crank edge corresponding to the end of the missing tooth portion Pa (crank edge at the missing tooth portion end position) occurs and at a crank edge next to the specific crank edge (position corresponding to the missing tooth portion end position). In this case, the current measurement value by the edge time measurement counter 32 is corrected to 1/3, and the corrected value is used to generate a multiplied clock. .

  For this reason, it is possible to realize generation of an angle signal that does not use a specific crank edge by using a hardware circuit (in this example, the hard crank 30) for generating an angle signal using all the crank edges.

  In the present embodiment, the specific crank edge corresponds to a specific pulse edge. The cylinders # 1 and # 4 in which the missing tooth portion Pa does not appear immediately before the TDC position correspond to the above-mentioned “specific cylinder” and “cylinder with specific pulse”, and the missing tooth portion Pa appears immediately before the TDC position. The appearing cylinders # 2 and # 3 correspond to the aforementioned “predetermined cylinder” and “cylinder without a specific pulse”. Further, the missing tooth portion equivalent range Pb corresponds to the aforementioned “specific range”, and the missing tooth portion Pa corresponds to the aforementioned “specific equivalent range”.

[Second Embodiment]
Next, the ECU according to the second embodiment will be described. As the reference numeral of the ECU, the same “1” as in the first embodiment is used. The same reference numerals as those in the first embodiment are used for the same components and processes as those in the first embodiment.

  Compared with the ECU 1 of the first embodiment, the ECU 1 of the second embodiment generates an angle signal without using a predetermined crank edge other than the aforementioned specific crank edge among the crank edges.

  In this example, the crank edge includes a crank edge at each 30 ° CA including a crank edge at a missing tooth portion start position, a missing tooth portion end position, a missing tooth portion start equivalent position, and a missing tooth portion equivalent end position. Only the edges (i.e., the crank edges every 30 ° CA with respect to the TDC position of each cylinder in this example) are used to generate the angle signal. That is, the crank edge (including the specific crank edge) generated between the crank edges every 30 ° CA is not used for the generation of the angle signal.

  Therefore, the CPU 11 performs the switching process of FIG. 7 instead of the switching process of FIG. In the following description of the second embodiment, the position at every 30 ° CA is the crank position at every 30 ° CA with reference to the TDC position of each cylinder. Further, the position one tooth before the position of every 30 ° CA is a crank position corresponding to a crank edge that is 10 ° CA before the position of every 30 ° CA. Similarly to the first embodiment, the CPU 11 determines the current crank position based on the value of the crank counter described above in the switching process of FIG.

  As shown in FIG. 7, when starting the switching process, the CPU 11 first determines in S210 whether or not the current crank position is every 30 ° CA, and the current crank position is every 30 ° CA. If so, the process proceeds to S220.

In S220, the CPU 11 determines whether or not the current crank position is the missing tooth portion start position. If the current crank position is not the missing tooth portion start position, the process proceeds to S230.
In S230, the CPU 11 controls the switching circuit 40 to prohibit the input of the crank signal to the hard crank 30, and then proceeds to S260. Note that the crank signal input prohibition state in S230 is continued until it is permitted in S250 described later. In the process of S230, two crank edges that occur between the crank edges every 30 ° CA (that is, the crank edge that occurred one time and the crank edges that occurred two times later) are input to the hard crank 30. It is a process for prohibiting it.

  If the CPU 11 determines in S210 that the current crank position is not every 30 ° CA position, the process proceeds to S240. Then, in S240, the CPU 11 determines whether or not the current crank position is a position one tooth before every 30 ° CA, and if the current crank position is a position one tooth before every 30 ° CA. Then, the process proceeds to S250. In S250, the CPU 11 controls the switching circuit 40 to permit the crank signal to be input to the hard crank 30 (in other words, to cancel the prohibition), and then proceeds to S260.

  Also, when the CPU 11 determines in S220 that the current crank position is the missing tooth start position, the CPU 11 proceeds to S250 and permits the input of the crank signal to the hard crank 30, and thereafter, S260. Proceed to

On the other hand, if the CPU 11 determines in S240 that the current crank position is not the position one tooth before the position of every 30 ° CA, the CPU 11 proceeds directly to S260.
By the processes of S210 to S250, only the crank edge at every 30 ° CA among the crank edges is input to the hard crank 30.

  In S260, the CPU 11 determines whether or not the current crank position is every 30 ° CA. If the current crank position is not every 30 ° CA, the CPU 11 ends the switching process as it is. If the crank position is every 30 ° CA, the process proceeds to S270.

  Then, in S270, the CPU 11 adds 2 to the value of the guard counter 35 in the same manner as S160 in FIG. 5, and in the next S280, in the same manner as S180 in FIG. The measured value is reduced to 1/3, and the value reduced to 1/3 is stored in the edge time storage register 33. Thereafter, the switching process is terminated.

  By the processes of S270 and S280, the substantial multiplication number and the guard value are changed to three times as compared with the case where the crank edge for every 10 ° CA is input to the hard crank 30. .

  When the CPU 11 performs the above switching process, the hard crank 30 generates an angle signal using only the crank edge for every 30 ° CA among the crank edges. The same effect as the ECU 1 of the first embodiment can be obtained by the ECU 1 of the second embodiment.

[First Modification]
In the first and second embodiments, the reference position portion for cylinder discrimination in the crank signal is the missing tooth portion Pa from which the pulse edge for each predetermined angle is missing, but the reference position portion is based on other pulse arrangement rules. Things can be used. For example, the reference position portion may be a portion where the intervals between the pulse edges become unequal by inserting an extra pulse edge (so-called extra teeth) in the middle of the row of pulse edges at every predetermined angle.

  As an example, in the crank signal shown in FIG. 8, a pulse edge (crank edge) is generated every 30 ° CA including the TDC position of each cylinder, but further to BTDC 10 ° CA of cylinders # 2 and # 3. Thus, a pulse edge as an extra tooth (hereinafter simply referred to as an extra tooth) is generated. Therefore, in the crank signal, the BTDC 30 ° CA to BTDC 10 ° CA portion of the cylinders # 2 and # 3 or the BTDC 10 ° CA to TDC portions of the cylinders # 2 and # 3 have unequal pulse edge intervals. It becomes the reference position part.

  When the angle signal is generated from the crank signal as shown in FIG. 8 by the microcomputer 10, the angle signal is generated by using only the pulse edge for every 30 ° CA, for example, without using extra teeth among the pulse edges. Should be generated.

In that case, CPU11 should just perform the process which changed the switching process of FIG. 7 as follows.
That is, the processing of S230 is performed at the timing of BTDC 30 ° CA of cylinders # 2 and # 3 in order to change the determination contents of S210, S220, and S240 in FIG. And the processing of S250 may be performed at the TDC timing of cylinders # 2 and # 3. In addition, what is necessary is just to perform the process of S260-S280 as it is.

  In the example of FIG. 8, the extra tooth corresponds to a specific pulse edge. The cylinders # 2 and # 3 in which extra teeth are generated in the 30 ° CA period immediately before the TDC correspond to the aforementioned “specific cylinders” and “cylinders with a specific pulse”, and are extra in the 30 ° CA period immediately before the TDC. The cylinders # 1 and # 4 in which no teeth are generated correspond to the aforementioned “predetermined cylinder” and “cylinder without a specific pulse”. Further, the range from BTDC 30 ° CA to TDC of cylinders # 2 and # 3 corresponds to the above-mentioned “specific range”, and the range from BTDC 30 ° CA to TDC of cylinders # 1 and # 4 is the above-mentioned “specific range”. It corresponds to “equivalent range”.

[Second Modification]
The rotation signal used to generate the angle signal is not limited to the crank signal, and may be a cam signal output from the cam sensor 23, for example. As described above, the cam sensor 23 generates a pulse edge (cam edge) by detecting teeth formed on the outer periphery of the rotor that rotates together with the cam shaft, but the cam shaft rotates in synchronization with the crankshaft. Therefore, the cam signal from the cam sensor 23 is also a rotation signal that generates a pulse edge every time the crankshaft rotates by a predetermined angle.

  As an example, in the cam signal shown in FIG. 9, a pulse edge (cam edge) is generated every 90 ° CA including the TDC position of each cylinder, and further, in any cylinder (# 2 in this example). At BTDC 30 ° CA, extra teeth for cylinder discrimination (pulse edges as extra teeth) are generated. For this reason, in the cam signal, the portion of BTDC 90 ° CA to BTDC 30 ° CA of cylinder # 2 or the portion of BTDC 30 ° CA to TDC of cylinder # 2 becomes a reference position portion with unequal pulse edge intervals.

  When the microcomputer 10 generates the angle signal from the cam signal as shown in FIG. 9, the angle signal is generated using only the pulse edge for every 90 ° CA, for example, without using extra teeth among the pulse edges. Should be generated. Further, for example, the angle signal may be generated using only the pulse edge every 180 ° CA.

  In the example of FIG. 9, the extra tooth corresponds to a specific pulse edge. The cylinder # 2 in which extra teeth are generated at BTDC 30 ° CA corresponds to the above-mentioned “specific cylinder” and “cylinder with specific pulse”, and the other cylinders # 1, # 3, and # 4 have the above-described “ It corresponds to “a predetermined cylinder” and “a cylinder without a specific pulse”. The range from BTDC 90 ° CA to TDC of cylinder # 2 corresponds to the above-mentioned “specific range”, and the range from BTDC 90 ° CA to TDC of cylinders # 1, # 3, and # 4 is the above-mentioned “specific range”. It corresponds to “equivalent range”.

As mentioned above, although embodiment of this invention was described, this invention can take a various form, without being limited to the said embodiment. The above-mentioned numerical values are also examples, and other values may be used.
For example, the switching of the input prohibition / permission of the rotation signal (crank signal or cam signal) to the hard crank 30 is not limited to being performed by the CPU 11 (in other words, software), but may be performed by hardware. May be. With such a configuration, the processing load on the CPU 11 can be reduced. Furthermore, if the correction processes such as S160 and S180 in FIG. 5 and S270 and S280 in FIG. 7 are also implemented by hardware, the processing load on the CPU 11 can be further reduced.

  In addition, the functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Moreover, you may abbreviate | omit a part of structure of the said embodiment as long as a subject can be solved. In addition, all the aspects included in the technical idea specified only by the wording described in the claim are embodiment of this invention. In addition to the ECU described above, the present invention is realized in various forms such as a system including the ECU as a constituent element, a program for causing a computer to function as the ECU, a medium storing the program, and a method for generating an angle signal. You can also

  DESCRIPTION OF SYMBOLS 1 ... ECU (engine control apparatus), 10 ... Microcomputer, 11 ... CPU, 30 ... Hard crank, 40 ... Switching circuit

Claims (6)

A rotation signal that generates a pulse edge every time the crankshaft of the engine rotates by a predetermined angle is input, and an angle signal that represents the crank position that is the rotation position of the crankshaft with a resolution smaller than the predetermined angle is input to the rotation signal. Angle signal generating means (10, 11, 30, 40, S110 to S180, S210 to S280) for generating based on
In the engine control device (1) for controlling the engine based on the angle signal generated by the angle signal generating means,
The rotation signal has a reference position part in which the intervals of the pulse edges are unequal in the middle of the row of the pulse edges,
The reference position in the rotation signal is
Since the pulse edge does not occur N times (N is an integer equal to or greater than 1), the interval between the pulse edges is a missing tooth portion (Pa) that is longer than the interval between the other pulse edges,
The missing tooth portion is
Among the plurality of cylinders of the engine, the cylinder appears at a crank angle that is advanced by a predetermined angle from the top dead center position of a predetermined cylinder, but from the top dead center position of a specific cylinder different from the predetermined cylinder. It does not appear at the crank position on the advance side by a predetermined angle,
The angle signal generating means includes
A specific pulse edge of the pulse edges in the rotation signal, and a relative positional relationship between the top dead center position of the predetermined cylinder and the missing tooth portion when viewed from the top dead center position of the specific cylinder; Generating the angle signal without using N specific pulse edges generated in the crank position range (Pb) having the same positional relationship ;
An engine control device. A rotation signal that generates a pulse edge every time the crankshaft of the engine rotates by a predetermined angle is input, and an angle signal that represents the crank position that is the rotation position of the crankshaft with a resolution smaller than the predetermined angle is input to the rotation signal. Angle signal generating means (10, 11, 30, 40, S230, S250 to S280) for generating based on
In the engine control device (1) for controlling the engine based on the angle signal generated by the angle signal generating means,
The rotation signal has a reference position part in which the intervals of the pulse edges are unequal in the middle of the row of the pulse edges,
The reference position in the rotation signal is
By inserting an extra tooth that is an extra pulse edge in the middle of a row of pulse edges for each predetermined angle, the interval between the pulse edges is unequal,
The extra teeth are
Among the plurality of cylinders of the engine, the cylinder does not occur at a crank position advanced by a predetermined angle from the top dead center position of a predetermined cylinder, but from a top dead center position of a specific cylinder different from the predetermined cylinder It occurs at the crank position on the advance side by the predetermined angle,
The angle signal generating means includes
Generating the angle signal without using the extra teeth that are specific pulse edges of the pulse edges in the rotation signal;
An engine control device. The engine control device according to claim 1 ,
The angle signal generating means (10, 11, 30, 40, S110 to S180)
First means (30) to which the rotation signal is input;
Second means (11, 40, S110 to S180) for changing the operation of the first means,
The first means includes
Measuring means (32) for sequentially measuring the interval between the pulse edges in the rotation signal input to the first means;
Multiplication clock output means (34) for outputting a multiplication clock having the time as one period for each time obtained by dividing the latest measurement value by the measurement means by a predetermined multiplication number;
A counter that performs a counting operation at a period of the multiplied clock, and a signal representing the count value includes an angle counter (38) that becomes the angle signal;
The second means includes
Prohibiting means (11, 40, S110 to S140) for prohibiting the specific pulse edge from being input to the measuring means among the pulse edges in the rotation signal;
In each of the pulse edge in the rotation signal, when the pulse edge corresponding to the end of the missing tooth portion occurs and when the next pulse edge after the specific pulse edge occurs, the measuring means Correction means (11, S180) for correcting the current measured value by 1 to a value of 1 / N + 1.
An engine control device. The engine control device according to any one of claims 1 to 3,
The rotation signal is
A crank signal from a crank sensor (21) that generates the pulse edge by detecting a plurality of teeth formed on an outer periphery of a rotor rotating together with the crankshaft;
An engine control device. The engine control apparatus according to claim 2 , wherein
The rotation signal is
A cam signal from a cam sensor (23) that generates the pulse edge by detecting a plurality of teeth formed on the outer periphery of a rotor that rotates together with the camshaft of the engine;
An engine control device. The engine control device according to any one of claims 1 to 5,
The angle signal generating means (10, 11, 30, 40, S210 to S280)
Generating the angle signal without using a predetermined pulse edge other than the specific pulse edge among the pulse edges in the rotation signal;
An engine control device.

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