JP4173497B2 - Control device for internal combustion engine for vehicle and method for determining bad road on vehicle road surface - Google Patents

Description

  The present invention relates to a control device for a vehicle internal combustion engine mounted on a vehicle such as an automobile and a rough road determination method for a vehicle traveling road surface, and more particularly to a control device for a vehicle internal combustion engine for performing misfire determination diagnosis of the internal combustion engine and the vehicle. The present invention relates to a rough road determination method for a running road surface.

  A technique is known in which misfire of an internal combustion engine (hereinafter referred to as an engine) is determined from a change in engine rotation speed, and when the misfire is determined, the determination result is displayed on a diagnostic result display means such as a warning lamp.

  Then, since the engine speed changes even when driving on a rough road, it is necessary to distinguish whether the engine speed change is caused by a bad road or a misfire in order to make an accurate misfire determination diagnosis. .

  Otherwise, an erroneous misfire determination may be performed when traveling on a rough road, and the reliability of the misfire determination is impaired.

  As a conventional technique, there is a technique in which wheel acceleration is detected by a sensor that detects a vehicle speed of a vehicle, and a road surface unevenness state is determined based on the wheel acceleration based on a predetermined evaluation method (for example, Patent Document 1). However, this technique is for a skid control device, a vehicle height control device, a suspension control device, and the like, and does not take into account the wheel acceleration change due to torque fluctuation due to engine misfire.

JP-A-6-318297

  In an internal combustion engine mounted on a vehicle such as an automobile, when a misfire determination is made based on a change in the engine speed, the engine speed change may not be due to misfire but may be due to a rough road. A misjudgment occurs only by misfire judgment by change. For this reason, in order to perform misfire determination more accurately than engine rotational speed change, it is necessary to perform misfire determination by excluding engine rotational speed change due to rough road traveling.

  The present invention has been made in view of the foregoing, and an object of the present invention is to perform misfire determination with no erroneous determination by accurately determining the bad road traveling in an internal combustion engine for a vehicle. Another object of the present invention is to provide a control device for an internal combustion engine for a vehicle and a method for determining a rough road on a vehicle traveling road surface.

In order to achieve the above object, a control apparatus for an internal combustion engine for a vehicle according to the present invention comprises a vehicle speed detection means for detecting the speed of the vehicle, an engine rotation speed detection means for detecting the rotation speed of the vehicle internal combustion engine, and the vehicle Vehicle speed signal frequency analyzing means for performing frequency analysis of the vehicle speed signal output by the speed detecting means, engine rotational speed signal frequency analyzing means for performing frequency analysis of the engine rotational speed signal output by the engine rotational speed detecting means, The frequency analysis result of the vehicle speed signal is compared with the frequency analysis result of the engine rotation speed signal, and it is determined from the comparison result whether or not the change in the rotation speed of the vehicle internal combustion engine is due to a rough road traveling of the vehicle. a control apparatus for an internal combustion engine for a vehicle having a road judging means, wherein the bad road judging means, means for obtaining a power spectrum of an arbitrary frequency orders of said vehicle speed signal And means for obtaining a power spectrum of the frequency of the engine rotational speed signal corresponding to the arbitrary order, and means for comparing the magnitudes of the power spectra of the frequencies of the two obtained signals. The means for obtaining the power spectrum of the frequency of the corresponding engine rotational speed signal corrects the gear position of the vehicle transmission to the power spectrum frequency of any order of the vehicle speed signal, and the gear position corrected frequency The power spectrum of the frequency of the engine speed signal having the frequency closest to is obtained .

Another aspect of the control device for a vehicle internal combustion engine according to the present invention is vehicle speed detection means for detecting the vehicle speed, engine rotation speed detection means for detecting the rotation speed of the vehicle internal combustion engine, and the vehicle speed detection means. Vehicle speed signal frequency analyzing means for performing frequency analysis of the vehicle speed signal output from the engine, engine rotational speed signal frequency analyzing means for performing frequency analysis of the engine rotational speed signal output by the engine rotational speed detecting means, and the vehicle speed signal A rough road determination means for comparing the frequency analysis result of the engine rotational speed signal and the frequency analysis result of the engine rotational speed signal, and determining whether or not the rotational speed change of the internal combustion engine for the vehicle is due to a rough road traveling, A misfire determination means for determining misfire of the vehicle internal combustion engine from a change in rotational speed of the vehicle internal combustion engine, and a misfire determination when the rough road determination means determines that the vehicle is traveling on a bad road. A control apparatus for an internal combustion engine for a vehicle having a misfire determination stopping means for stopping misfire judgment by means of, the bad road judging means includes means for obtaining a power spectrum of an arbitrary frequency orders of said vehicle speed signal And means for obtaining a power spectrum of the frequency of the engine rotational speed signal corresponding to the arbitrary order, and means for comparing the magnitudes of the power spectra of the frequencies of the two obtained signals. The means for obtaining the power spectrum of the frequency of the corresponding engine rotational speed signal corrects the gear position of the vehicle transmission to the power spectrum frequency of any order of the vehicle speed signal, and the gear position corrected frequency The power spectrum of the frequency of the engine speed signal having the frequency closest to is obtained .

  In the control apparatus for an internal combustion engine for a vehicle according to the present invention, preferably, the rough road determination means is a frequency whose power spectrum of an arbitrary order frequency of the vehicle speed signal corresponds to the arbitrary order of the engine rotational speed signal. If it is larger than the power spectrum, it is determined that the road is bad.

  In the method for determining a rough road on the vehicle traveling road surface according to the present invention, the vehicle speed detecting means detects the vehicle speed, the engine rotation speed detecting means detects the rotation speed of the vehicle internal combustion engine, and the vehicle speed detecting means outputs the detected vehicle speed. The frequency analysis of each of the vehicle speed signal and the engine rotation speed signal output by the engine rotation speed detection means is performed, and the power spectrum of the frequency of the arbitrary order of the vehicle speed signal becomes the arbitrary order of the engine rotation speed signal. A bad road is determined when the power spectrum is larger than the corresponding frequency.

The present invention is based on the fact that the power spectrum of the frequency analysis result of the vehicle speed signal is larger than the power spectrum of the engine rotational speed signal in the case of rough road driving, and vice versa in the case of misfire. By switching the order of the power spectrum to be compared according to the traveling conditions, it is possible to reduce the influence of disturbances such as vehicle natural vibrations and improve the determination accuracy. If it is determined that the road is bad, the misfire diagnosis of the vehicle internal combustion engine is stopped, so that the influence of the bad road is not erroneously determined as misfire.

An embodiment of a control device for an internal combustion engine for a vehicle according to the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing the overall concept of a vehicle internal combustion engine to which the control device of this embodiment is applied. A vehicle internal combustion engine (engine) 201 is a multi-cylinder engine, for example, a 4-cylinder engine. It has four cylinder bores 221. Each of the four cylinder bores 221 is provided with a piston 222, and a combustion chamber 223 is formed in each cylinder bore 221. In FIG. 1, only one cylinder (combustion chamber 223) is shown.

  The engine 201 has a throttle throttle valve 202, an idle speed control valve (ISC valve) 203, and a swirl control valve 211 for the amount of air to be taken in the intake system.

  The idle speed control valve 203 controls the flow area of the flow path connected to the intake pipe 204 by bypassing the throttle throttle valve 220, and controls the rotational speed of the engine 201 during idling.

  The swirl control valve 211 is a valve having a notch, and selectively forms a swirl in the flow of intake air by turning on / off (closing / opening).

  An intake pipe pressure sensor 205 that detects the pressure in the intake pipe 204 and a throttle opening degree sensor 216 that detects the opening degree of the throttle throttle valve 202 are attached to the intake pipe 204.

  The engine 201 is provided with a fuel injection valve 206 for injecting and supplying fuel to the intake port 201A of each cylinder of the engine 201.

  The engine 201 has an ignition module 208 that supplies ignition energy to an ignition plug 224 that ignites a mixture of fuel and air supplied into the combustion chamber 223 based on an ignition signal output from the engine control device 215. It has been.

  The engine 201 also includes a camshaft sensor 207 that detects the cam angle of the intake valve, a crank angle sensor (engine rotational speed detection means) 213 that detects the crank angle of the engine 201, and a coolant temperature of the engine 201. A water temperature sensor 209 is provided. An oxygen concentration sensor 210 that detects the oxygen concentration in the exhaust gas is attached to the exhaust pipe 225 of the engine 201. In this embodiment, the oxygen concentration sensor 210 outputs a signal proportional to the exhaust air-fuel ratio, but the exhaust gas outputs two signals on the rich side / lean side with respect to the stoichiometric air-fuel ratio. You may do it.

  The engine control device 215 is of a microcomputer type, and includes the aforementioned sensors 205, 209, 213, 210, and 216, an ignition key switch 212 that is a main switch for operating and stopping the engine 201, and a propeller shaft of a vehicle. A signal indicating the state of the engine 201 and a signal indicating the vehicle speed are input from a vehicle speed sensor (vehicle speed detecting means) 214 that detects the vehicle speed by detecting the rotation of the vehicle, and arithmetic processing is performed to perform fuel control, ignition control, and misfire Diagnosis, rough road determination, etc.

  Although the idling speed of the engine 201 is controlled by the idle speed control valve 203, when the throttle throttle valve 202 is controlled by a motor or the like, the idle speed control valve 203 is unnecessary. In this embodiment, the fuel control is established by detecting the intake pipe pressure, but the fuel control is established even if the intake air amount of the engine is detected.

  As shown in FIG. 2, the engine control device 215 converts the electrical signals of the aforementioned sensors installed in the engine 201 into signals for digital calculation processing, and converts the digital calculation control signals into actual signals. The state of the engine 201 is determined from an I / O driver (LSI) 301 that converts it into an actuator drive signal, and a digital arithmetic processing signal from the I / O driver 301, and the fuel amount, ignition timing, etc. required by the engine 201 Is calculated based on a predetermined procedure, and the arithmetic unit (MPU) 302 that sends the calculated value to the I / O driver 301, and a non-volatile memory in which the control procedure and control constants of the arithmetic device 302 are stored 303 and a volatile memory 304 in which the calculation result of the arithmetic unit is stored.

  The volatile memory 304 may be connected to a backup power supply for the purpose of storing memory contents even when the above-described ignition key switch is off and power is not supplied to the engine control device 215.

  In the engine control device 215 of this embodiment, a water temperature sensor 209, a crank angle sensor 213, a camshaft sensor 207, an oxygen concentration sensor 210, an intake pipe pressure sensor 205, a throttle opening sensor 216, a vehicle speed sensor 214, and an ignition key switch 212 A signal is input, a fuel injection signal to the first to fourth cylinder fuel injection means 111 to 114, an ignition command signal to the first to fourth cylinder ignition coils 115 to 118, and an opening command signal to the ISC valve 203, A diagnostic signal is output to the diagnostic result display lamp 120.

  In addition, the 1st-4th cylinder fuel-injection means 111-114 represent the fuel-injection valve 206 of FIG. 1 for every cylinder. The first to fourth cylinder ignition coils 115 to 118 are ignition coils of the respective cylinders included in the ignition module 208 of FIG.

  Control performed by the engine control apparatus 215 according to the present embodiment will be described with reference to the control block diagram of FIG.

  The engine control unit 215 is configured such that when the MPU 302 executes a computer program, the engine speed calculation unit 101, the basic fuel calculation unit 102, the basic fuel correction coefficient calculation unit 103, the basic ignition timing calculation unit 104, the ISC control unit 105, A misfire determination means 106 with a road determination, an air-fuel ratio feedback control coefficient calculation means 107, a target air-fuel ratio setting means 108, a basic fuel correction means 109, and an ignition timing correction means 110 are embodied.

  The engine speed calculation means 101 counts and calculates the electrical signal of the crank angle sensor 213 set at a predetermined crank angle position of the engine 201, mainly the number of inputs per unit time of the pulse signal change. Thus, the number of revolutions per unit time of the engine 201 is calculated.

  The basic fuel calculation means 102 uses the intake pipe pressure detected by the intake pipe pressure sensor 205 installed in the intake pipe 204 of the engine 201 as an engine load, and the engine load and the engine speed calculated by the engine speed calculation means 101. Thus, the basic fuel required by the engine 201 in each region is calculated.

  The basic fuel correction coefficient calculation means 103 performs each operation of the engine 201 of the basic fuel calculated by the basic fuel calculation means 102 based on the engine speed calculated by the engine speed calculation means 101 and the engine load indicated by the intake pipe pressure. The correction coefficient in the area is determined by map search or the like.

  The basic ignition timing calculation means 104 determines the optimal ignition timing in each region of the engine 201 by map search or the like based on the engine load due to the engine speed and the intake pipe pressure.

  The ISC control means 105 calculates the target rotational speed during idling and calculates the target flow rate of the ISC valve 203 in order to keep the idling rotational speed of the engine 201 constant.

  The target air-fuel ratio setting means 108 determines an optimal target air-fuel ratio in each region of the engine 201 by map search or the like based on the engine load due to the engine speed and the intake pipe pressure.

  The air / fuel ratio feedback control coefficient calculation means 107 sets the fuel / air mixture supplied to the engine 201 from the output of the oxygen concentration sensor 210 set in the exhaust pipe 225 of the engine 201 by the target air / fuel ratio setting means 108. An air-fuel ratio feedback control coefficient by PID control is calculated so that the target air-fuel ratio is maintained.

  The basic fuel correction means 109 uses the basic fuel calculated by the block basic fuel calculation means 102 as the basic fuel correction coefficient by the basic fuel correction coefficient calculation means 103, the engine water temperature, and the air-fuel ratio feedback control coefficient by the air-fuel ratio feedback control coefficient calculation means 107. Correction (fuel amount Tiout calculation) is performed by the control coefficient.

  The fuel injection means 111 to 114 for each cylinder inject fuel so that the fuel amount Tout calculated by the basic fuel correction means 109 is supplied to each cylinder.

  The ignition timing correction means 110 corrects the ignition timing searched by the basic ignition timing calculation means 104 based on the engine state (transient or steady) and the target flow rate of the ISC valve 203 by the ISC control means 105 (ADV calculation). To do.

  The ignition coils 115 to 118 of each cylinder ignite the air-fuel mixture according to the required ignition timing of the engine corrected by the ignition timing correction means 110.

The misfire determination means 106 with a rough road determination uses the signal of the crank angle sensor 213 ( engine speed signal) and the signal of the vehicle speed sensor 214 (vehicle speed signal) to determine misfire of the engine 201 and It is determined whether or not the traveling road surface is a bad road based on the frequency analysis result.

  The misfire determination by the misfire determination means 106 is transmitted to the driver by the diagnosis result display means 120 using a lamp in the driver's seat. This diagnostic result display is performed so that it can be distinguished from the others by the number of times the lamp blinks, the blinking interval, and the like.

  The target air-fuel ratio setting means 108 determines an optimal target air-fuel ratio in each region of the engine 201 by map search or the like based on the engine load due to the engine speed and the intake pipe pressure.

  4 and 5 show an example of the power spectrum of the frequencies of the crank angle sensor signal (the signal of the crank angle sensor 213) and the vehicle speed sensor signal (the signal of the vehicle speed sensor 214). A line (solid line) 401 indicates a power spectrum of the frequency of the vehicle speed sensor signal, and a line (broken line) 402 indicates a power spectrum of the frequency of the crank angle sensor signal.

  FIG. 4 is a power spectrum in a state where the vehicle is traveling on a rough road. The power spectrum peak 403 of the frequency of the vehicle speed sensor signal appears in the power spectrum peak 404 of the frequency of the crank angle sensor signal at a frequency corresponding to the gear ratio, and the magnitude of the peak value is the power spectrum peak 403 of the frequency of the vehicle speed sensor signal. Is larger than the power spectrum peak 404 of the frequency of the crank angle sensor signal.

  FIG. 5 is a power spectrum in a state where the engine 201 is traveling on a non-bad road while misfiring. A power spectrum peak 504 of the frequency of the crank angle sensor signal appears in a power spectrum peak 503 of the frequency of the vehicle speed sensor signal at a frequency corresponding to the gear ratio, and the magnitude of the peak value is a power spectrum peak of the frequency of the crank angle sensor signal. 504 is larger than the power spectrum peak 503 of the frequency of the vehicle speed sensor signal.

  FIG. 6 shows an example of data acquisition for frequency analysis of a crank angle sensor signal used for rough road determination.

  Crank angle sensor signals at regular intervals indicated by the interval 601 are sampled in an overlapping manner as in the data strings 602 to 604, and subjected to frequency analysis in the order indicated by n. The frequency analysis of the crank angle sensor signal is performed using a time angle of the crank angle sensor signal or a numerical value converted into the engine speed. Note that there is no problem even if the frequency analysis is performed only on the data string 602.

  FIG. 7 shows an example of data acquisition for frequency analysis of a vehicle speed sensor signal used for rough road determination.

  The vehicle speed sensor signals at regular intervals indicated by the interval 701 are sampled in an overlapping manner as in the data strings 702 to 704, and subjected to frequency analysis in the order indicated by n. The frequency analysis of the vehicle speed sensor signal is performed using a time angle of the vehicle speed sensor signal or a numerical value converted into the vehicle speed. Note that there is no problem even if the frequency analysis is performed only on the data string 702.

Details of the misfire determination means with rough road determination 106 will be described with reference to FIG.
The misfire determination unit 106 with a rough road determination includes a rough road determination unit 801, a logical product gate unit 802, a switch 803, a rotation angular velocity change detection unit 804, and a misfire determination unit 805.

  The rough road determination unit 801 performs bad road determination based on the vehicle speed sensor signal, the crank angle sensor signal, and the gear position signal.

  The gear position is a shift position (gear position) of a vehicle transmission (not shown) connected to the engine 201. In this embodiment, the gear position signal is calculated based on the engine speed and the vehicle speed. Ask. The gear position signal can also be input from a transmission control device (not shown).

  The AND gate 802 determines whether or not all the conditions for the water temperature condition, the engine speed condition, the engine load condition, the throttle opening condition, and the aforementioned rough road determination are met. It is assumed that the rough road determination is satisfied when it is determined that the road is not a bad road.

  When it is determined by the AND gate 802 that all the conditions are satisfied, the switch 803 serving as the misfire determination stop means is turned on (closed), and the crank angle sensor signal is input to the rotation angular velocity change detection unit 804. It is. Based on the result, the misfire determination unit 805 detects misfire. The result of misfire detection is finally transmitted to the driver by the diagnostic result display means 120.

  Thus, when it is determined that the road is a bad road, the misfire diagnosis of the engine 201 is stopped, so that the influence of the bad road is not erroneously determined as a misfire. As a result, the reliability of misfire determination is improved.

Next, details of the rough road determination unit 801 will be described with reference to FIG. 9. The rough road determination unit 801 includes a vehicle speed sensor signal frequency analysis unit 901 and n power spectrum peak value / peak frequency detection units 902 _1. ˜902n, a crank angle sensor signal frequency analysis unit 904, n power spectrum peak value / peak frequency detection units 905 _{1 to} 905n, and a road surface (bad road) determination execution unit 907.

The vehicle speed sensor signal frequency analysis unit 901 performs frequency analysis of the vehicle speed sensor signal. Then, from the frequency analysis result of the vehicle speed sensor signal, the power spectrum peak value and peak frequency of the frequency of the vehicle speed sensor signal are respectively determined by n power spectrum peak value / peak frequency detection units 902 _{1 to} 902 n. This corresponds to a means for obtaining a power spectrum of a frequency of an arbitrary order of the vehicle speed signal.

The crank angle sensor signal frequency analysis unit 904 performs frequency analysis of the crank angle sensor signal. Then, from the frequency analysis result of the crank angle sensor signal, the power spectrum peak value and peak frequency of the frequency of the crank angle sensor signal are respectively obtained by n power spectrum peak value / peak frequency detection units 905 _{1 to} 905 n. This corresponds to means for obtaining a power spectrum of the frequency of the engine rotational speed signal corresponding to an arbitrary order.

  The road surface determination execution unit 907 performs road surface determination (bad road determination) based on the peak value of the power spectrum of each frequency of the vehicle speed sensor signal and the crank angle sensor signal, the peak frequency, and the gear position signal.

Next, details of the road surface determination execution unit 907 will be described with reference to FIG.
Road-execution unit 907 includes n peak value comparator 1001 _1, 1001 _{2 ~1001n,} the condition determining unit 1002, a switch 1003 ₁ ~1003n of each peak value comparator 1001 per ₁ ～1001N, the output unit AND gate means 1004 is included.

The n peak value comparators 1001 _{1 to} 1001 n compare the peak frequency and peak value of the frequency of the vehicle speed sensor signal with the power spectrum peak frequency and peak value of the frequency of the crank angle sensor signal. Each of the n peak value comparators 1001 _{1 to} 1001 n receives a first-order to n-th order power spectrum of the frequency of the vehicle speed sensor signal, and a power spectrum of all orders of the frequency of the crank angle sensor signal inputted simultaneously. Compare.

The condition determination unit 1002 determines conditions based on the engine water temperature, engine speed, engine load, and throttle opening, and determines which power spectrum order comparison value is used for rough road determination. To switch the switches 1003 _{1 to} 1003n.

Details of the peak value comparators 1001 _{1 to} 1001 n of arbitrary orders will be described with reference to FIG. The peak value comparators 1001 _{1 to} 1001 n include a gear position correction unit 1101, a power spectrum order selection unit 1102, a switch circuit 1103, a deviation calculation unit 1004, and a comparison determination unit 1005.

  The gear position correction unit 1101 adds gear position correction to the vehicle speed sensor signal power spectrum frequency of an arbitrary order.

  The power spectrum order selection unit 1102 selects the order of the power spectrum of the frequency of the crank angle sensor signal corresponding to the vehicle speed sensor signal power spectrum frequency with the gear position corrected.

  The switch circuit 1103 selects the power spectrum peak value of the frequency of the corresponding crank angle sensor signal based on the order selected by the power spectrum order selection unit 1102. In this embodiment, the power spectrum peak value of the frequency of the crank angle sensor signal having the frequency closest to the gear position corrected frequency is selected.

  The deviation calculation unit 1104 is a deviation between the power spectrum peak value of the crank angle sensor signal frequency and the power spectrum peak value of the vehicle speed sensor signal frequency (power spectrum peak value of the crank angle sensor signal frequency) − (vehicle speed sensor signal Frequency power spectrum peak value) is calculated.

  The comparison determination unit 1105 determines that the vehicle is traveling on a rough road when the deviation calculated by the deviation calculation unit 1104 is equal to or greater than a predetermined value (the deviation is a negative value and the deviation is equal to or greater than a predetermined value). It is determined that the vehicle is traveling on a rough road when the power spectrum of the frequency of the vehicle speed sensor signal is larger than a predetermined value than the power spectrum of the frequency of the selected crank angle sensor signal.

  As shown in FIGS. 4 and 5, when driving on a rough road, the power spectrum of the frequency analysis result of the vehicle speed sensor 214 becomes larger than the power spectrum of the frequency of the crank angle sensor 213, and vice versa in the case of misfire. Therefore, the fact that the power spectrum of the frequency of the vehicle speed sensor signal is larger than the power spectrum of the frequency of the selected crank angle sensor signal is the state shown in FIG. It is determined that the vehicle is traveling on a rough road.

The comparison threshold (predetermined value) may be a variable according to the state of the engine 201.
Further, since the order of the power spectrum to be compared is switched depending on the driving conditions of the vehicle, it is possible to reduce the influence of disturbances such as natural vibration of the vehicle and improve the determination accuracy of the rough road.

  Next, an engine control and rough road determination processing routine by the engine control device 215 will be described with reference to a flowchart shown in FIG. This routine is repeatedly executed by interruption for a predetermined time.

  First, the engine speed is calculated from the output signal of the crank angle sensor 213 (step 1201), and then the engine load is read by the output signal of the intake pipe pressure sensor 205 (step 1202).

  Next, the basic fuel amount is calculated from the engine speed and the engine load (step 1203).

  Next, a basic fuel amount correction coefficient is searched (step 1204), and then the target air-fuel ratio is searched (step 1205).

  Next, the output signal of the oxygen concentration sensor 210 is read (step 1206), and the air-fuel ratio feedback control coefficient is calculated from the output signal of the oxygen concentration sensor 210 (step 1207).

  Next, the basic fuel amount is corrected by the basic fuel amount correction coefficient and the air-fuel ratio feedback control coefficient (step 1208).

  Next, the output signal of the vehicle speed sensor 214 is captured (step 1209), the frequency analysis of the captured vehicle speed sensor signal is performed, and the power spectrum of the frequency of the arbitrary order vehicle speed sensor signal is calculated (step 1210).

  Next, the output signal of the crank angle sensor 213 is fetched (step 1211), the frequency analysis of the fetched crank angle sensor signal is performed, and the power spectrum of the frequency of the crank angle sensor signal of any order is calculated (step 1212).

  Next, a rough road is determined based on the power spectrum of the frequency of the vehicle speed sensor signal and the power spectrum of the frequency of the crank angle sensor signal (step 1213).

  Next, a target engine speed (ISC target engine speed) during idling is calculated (step 1214), and an ISC flow rate that satisfies the target engine speed is calculated (step 1215).

  Next, a correction amount (ignition ISC correction amount) for maintaining the target rotational speed of the ISC in the ignition control is calculated (step 1216).

  Next, the basic ignition timing is calculated (step 1217), and the basic ignition timing is corrected by the ignition ISC correction amount (step 1218).

  Next, a processing routine of misfire determination (misfire detection) by the engine control device 215 that performs rough road determination will be described with reference to a flowchart shown in FIG. This processing routine is executed with constant crank angle synchronization.

  First, the crank angular speed (engine speed) is detected from the crank angle sensor signal (step 1301).

  Next, misfire determination conditions are read (step 1302), and it is determined whether or not misfire determination is performed (step 1303). If the misfire determination condition is satisfied, the misfire determination is executed (step 1304).

  The misfire determination condition includes a condition that the misfire determination is not performed when the bad road is determined. Therefore, the misfire determination is not performed when the bad road is determined.

  Next, a misfire determination (misfire detection) and rough road determination processing routine by the processing apparatus configured as shown in FIG. 8 will be described with reference to the flowchart shown in FIG. This routine is repeatedly executed by interruption for a predetermined time.

  First, a vehicle speed sensor signal, a crank angle sensor signal, and a gear position are read (steps 1401 to 1403).

  Next, a bad road is determined based on the vehicle speed sensor signal, the crank angle sensor signal, and the gear position (step S1404).

  Next, as a misfire condition determination, if all the conditions of not a bad road, water temperature condition, engine speed, engine load, and slot opening condition are satisfied, the misfire detection result is read (step 1410), and the diagnosis result display means is set. Then, control is performed according to the read misfire detection result (step 1411).

  Next, a rough road determination processing routine by the processing apparatus having the configuration as shown in FIG. 9 will be described with reference to the flowchart shown in FIG. This routine is repeatedly executed by interruption for a predetermined time.

  First, a vehicle speed sensor signal is read (step 1501), and frequency analysis of the read vehicle speed sensor signal is performed (step 1502).

  Next, a peak value of a predetermined order (nth order) from the power spectrum of the frequency of the vehicle speed sensor signal is detected (step 1503). Further, a peak frequency of a predetermined order (nth order) of the power spectrum of the frequency of the vehicle speed sensor signal is detected (step S1504).

  Next, a crank angle sensor signal is read (step 1505), and frequency analysis of the read crank angle sensor signal is performed (step 1506).

  Next, a peak value of a predetermined order (nth order) is detected from the first order of the power spectrum of the frequency of the crank angle sensor signal (step 1507). Further, a peak frequency of a predetermined order (n-order) from the power spectrum of the frequency of the crank angle sensor signal is detected (step S1508).

  Next, the gear position is read (step S1509), and the rough road is determined based on the peak value and peak frequency of the power spectrum of the vehicle speed sensor signal and the crank angle sensor signal in consideration of the gear position (step 1510).

  Next, a processing routine for performing rough road determination with the peak value and peak frequency of the power spectrum by the processing device having the configuration shown in FIG. 10 will be described with reference to the flowchart shown in FIG. This routine is repeatedly executed by interruption for a predetermined time.

  First, the peak frequency of the arbitrary order of the vehicle speed sensor signal is read (step 1601), and then the peak value of the power spectrum of the arbitrary order frequency of the vehicle speed sensor signal is read (step 1602).

  Next, all the peak frequencies of the arbitrary order from the first order of the crank angle sensor signal are read (step S1603), and then all the peak values of the power spectrum of the first order to the arbitrary order of the frequency of the crank angle sensor signal are read. Read (step 1604).

  Next, the gear position is read (step 1605), the gear position correction is applied to the peak frequency of the arbitrary order of the vehicle speed sensor signal, and the frequency of the crank angle sensor signal corresponding to the power spectrum of the frequency of the arbitrary order of the vehicle speed sensor signal. Are compared with each other (step 1606).

  Next, it is determined whether or not the reading of the power spectrum of all the frequencies of the vehicle speed sensor signal has been completed (step 1607).

  When it is determined that all the power spectra have been read, it is determined whether the engine water temperature conditions, engine speed conditions, engine load conditions, and throttle opening conditions of each arbitrary order are satisfied ( Steps 1608 to 1611) When all the conditions are satisfied, a power spectrum comparison result of an arbitrary order is output (Step 1613). On the other hand, if all the conditions are not satisfied, OK is output as a comparison result (step 1612).

  Next, it is determined whether or not the output of comparison results for all power spectra has been completed (step 1614). If completed, it is determined whether or not all comparison results are OK (step 1615). If all the comparison results are OK, the bad road determination for the misfire diagnosis is canceled (step 1616). On the other hand, if all the comparison results are not OK, a bad road determination for misfire diagnosis is set (step 1617).

  Next, a processing routine for comparing peak values of power spectra of arbitrary orders of the vehicle speed sensor signal by the processing device having the configuration shown in FIG. 11 will be described with reference to the flowchart shown in FIG. This routine is repeatedly executed by interruption for a predetermined time.

First, the peak frequency of an arbitrary order of the vehicle speed sensor signal is read (step 1701).
Next, the gear position is read (step 1702), and a gear position correction coefficient is calculated from the read gear position (step 1703).

  Next, gear position correction of an arbitrary order peak frequency of the vehicle speed sensor signal is performed using the calculated gear position correction coefficient (step S1704).

  Next, the peak frequency of each order crank angle sensor signal is read (step 1705), the peak frequency of an arbitrary number order vehicle speed sensor signal subjected to gear position correction and the peak of each order crank angle sensor signal. Each frequency is compared (steps 1705 to 1707).

  Next, the peak value of the power spectrum of the frequency of the crank angle sensor signal with the smallest comparison value is selected (step 1708). For example, the peak frequency of the crank angle sensor signal closest to the peak frequency of the vehicle speed sensor signal whose gear position has been corrected is selected.

  The peak value of the power spectrum of the frequency of an arbitrary several-order vehicle speed sensor signal is compared with the peak value of the power spectrum of the selected crank angle sensor signal (step 1709), and the deviation is negative and greater than a predetermined value It is determined whether or not (step 1710). That is, it is determined whether or not the peak value of the power spectrum of the frequency of the vehicle speed sensor signal is smaller than the peak value of the power spectrum of the frequency of the crank angle sensor signal by a predetermined value or more. If this determination is true, it is determined that the road is not a bad road (step 1711), and if it is false, it is determined that the road is a bad road (step 1712).

  As a result, accurate rough road determination is performed, and accordingly, the influence of the bad road is not erroneously determined as misfire, and the reliability of the misfire determination is improved.

BRIEF DESCRIPTION OF THE DRAWINGS The whole block diagram which shows one Embodiment of the internal combustion engine for vehicles to which the control apparatus by this invention is applied. The control block diagram of the internal combustion engine for vehicles to which the control apparatus of FIG. 1 was applied. The control block diagram of the engine control apparatus by this embodiment. The graph which shows an example (at the time of a rough road driving | running | working) of the power spectrum of the frequency of the signal of the crank angle sensor of a vehicle engine, and a vehicle speed sensor. The graph which shows the other example (at the time of non-bad road driving | running | working) of the power spectrum of the frequency of the signal of the crank angle sensor of a vehicle engine, and a vehicle speed sensor. The time chart which shows an example of the data acquisition of the crank angle sensor of the engine control apparatus by this embodiment. The time chart which shows an example of the data acquisition of the vehicle speed sensor of the engine control apparatus by this embodiment. The control block diagram which shows the detail of the misfire determination means of the engine control apparatus by this embodiment. The control block diagram which shows the detail of the rough road determination part of the engine control apparatus by this embodiment. The control block diagram which shows the detail of the road surface determination execution part of the engine control apparatus by this embodiment. The control block diagram which shows the detail of the peak value comparator of the engine control apparatus by this embodiment. The flowchart which shows the process routine of the engine control by the engine control apparatus by this embodiment, and rough road determination. The flowchart which shows the processing routine of misfire determination (misfire detection) by the engine control apparatus which performs rough road determination by this embodiment. The flowchart which shows the processing routine of misfire determination (misfire detection) and rough road determination by the engine control apparatus of this embodiment. The flowchart which shows the processing routine of the bad road determination by the engine control apparatus of this embodiment. The flowchart which shows the process routine which performs a rough road determination by the peak value and peak frequency of a power spectrum by the engine control apparatus of this embodiment. The flowchart which shows the processing routine of the peak value comparison of the power spectra of the arbitrary orders of the vehicle speed sensor signal by the engine control apparatus of this embodiment.

Explanation of symbols

106 Misfire determination means 120 Diagnosis result display means 201 Engine 213 Crank angle sensor 214 Vehicle speed sensor 215 Engine control device 302 Computing device 801 Rough road determination unit 804 Rotational angular velocity change detection unit 805 Misfire determination unit 901 Vehicle speed sensor signal frequency analysis unit 902 ₁ to 902n Power spectrum peak value / peak frequency detection unit 904 Crank angle sensor signal frequency analysis unit 905 _{1 to} 905n Power spectrum peak value / peak frequency detection unit 907 Road surface determination execution unit 1001 _{1 to} 1001n Peak value comparator 1002 Condition determination unit 1101 Gear Position correction unit 1102 Power spectrum order selection unit 1004 Deviation calculation unit 1005 Comparison determination unit

Claims (4)

Vehicle speed detection means for detecting the speed of the vehicle, engine rotation speed detection means for detecting the rotation speed of the internal combustion engine for the vehicle, and vehicle speed signal frequency analysis for analyzing the frequency of the vehicle speed signal output from the vehicle speed detection means The engine rotational speed signal frequency analyzing means for analyzing the frequency of the engine rotational speed signal output from the engine rotational speed detecting means, and comparing the frequency analysis result of the vehicle speed signal and the frequency analysis result of the engine rotational speed signal. and, from the comparison result, the rotational speed variation of the engine for the vehicle the vehicle control apparatus for an internal combustion engine for chromatic and bad road judging means for judging whether or not due to the rough road running of the vehicle, and
The bad road judging means is a means for obtaining a power spectrum of a frequency of an arbitrary order of the vehicle speed signal, a means of obtaining a power spectrum of a frequency of an engine rotational speed signal corresponding to the arbitrary order, and obtained 2 Means for comparing the magnitudes of the power spectra of the frequencies of the two signals,
The means for obtaining the power spectrum of the frequency of the engine rotational speed signal corresponding to the arbitrary order corrects the gear position of the vehicle transmission to the frequency of the power spectrum of the arbitrary order of the vehicle speed signal. A control apparatus for an internal combustion engine for a vehicle, wherein a power spectrum of a frequency of an engine rotation speed signal having a frequency closest to the position-corrected frequency is obtained . Vehicle speed detection means for detecting the speed of the vehicle, engine rotation speed detection means for detecting the rotation speed of the internal combustion engine for the vehicle, and vehicle speed signal frequency analysis for analyzing the frequency of the vehicle speed signal output from the vehicle speed detection means The engine rotational speed signal frequency analyzing means for analyzing the frequency of the engine rotational speed signal output from the engine rotational speed detecting means, and comparing the frequency analysis result of the vehicle speed signal and the frequency analysis result of the engine rotational speed signal. Then, based on the comparison result, rough road determination means for determining whether or not the change in rotational speed of the internal combustion engine for the vehicle is due to running on a rough road, and the change in rotational speed of the internal combustion engine for the vehicle Misfire determination means for performing misfire determination; and misfire determination stop means for stopping misfire determination by the misfire determination means when the rough road determination means determines that the road is running on a rough road; Yes to a control apparatus for an internal combustion engine for a vehicle,
The bad road judging means is a means for obtaining a power spectrum of a frequency of an arbitrary order of the vehicle speed signal, a means of obtaining a power spectrum of a frequency of an engine rotational speed signal corresponding to the arbitrary order, and obtained 2 Means for comparing the magnitudes of the power spectra of the frequencies of the two signals,
The means for obtaining the power spectrum of the frequency of the engine rotational speed signal corresponding to the arbitrary order corrects the gear position of the vehicle transmission to the frequency of the power spectrum of the arbitrary order of the vehicle speed signal. A control apparatus for an internal combustion engine for a vehicle, wherein a power spectrum of a frequency of an engine rotational speed signal having a frequency closest to the position-corrected frequency is obtained . The rough road determining means determines that the road is a rough road when a power spectrum of an arbitrary order frequency of the vehicle speed signal is larger than a power spectrum of a frequency corresponding to the arbitrary order of the engine rotational speed signal. 3. The control device for an internal combustion engine for a vehicle according to claim 1, wherein the control device is an internal combustion engine. The vehicle speed detection means detects the vehicle speed, the engine rotation speed detection means detects the rotation speed of the vehicle internal combustion engine, and the vehicle speed signal output by the vehicle speed detection means and the engine rotation speed detection means output. Analyzing the frequency of each engine speed signal, and if the power spectrum of an arbitrary order frequency of the vehicle speed signal is larger than the power spectrum of a frequency corresponding to the arbitrary order of the engine speed signal, a rough road It is a rough road judgment method of the vehicle running road which judges that,
The power spectrum of the frequency of the engine rotational speed signal corresponding to the arbitrary order is the engine whose frequency is closest to the frequency of the power spectrum of the arbitrary order of the vehicle speed signal corrected by the gear position of the vehicle transmission. It is a power spectrum of the frequency of the rotation speed signal,
The rough road determination includes two power spectrums of an arbitrary frequency of the obtained vehicle speed signal and a power spectrum of an engine rotational speed signal corresponding to the arbitrary order corrected by the gear position. A method for determining a rough road on a vehicle traveling road surface, wherein the determination is made by comparing the magnitudes of power spectra of signal frequencies .

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