JP2008157198A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control device capable of restraining erroneous determination that an abnormality has occurred, when determining the existence of the occurrence of the abnormality on a sensor for detecting a rotating position. <P>SOLUTION: A crank angle estimating part 320 estimates an estimated crank angle CRK of a crankshaft based on a rotating speed MRN1 and MRN2 of a motor generator. A crank angle variation calculating part 322 calculates an angle variation ΔCRK between continuous two pulses of a cam angle signal CP. When the angle variation ΔCRK is smaller than a minimum angle interval ΔCPmin, it is determined as the occurrence of chattering in the cam angle signal CP, and when first and second condition signals are activated, a mask signal MSK is issued, and an abnormality determining signal FLT is invalidated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle having an internal combustion engine, and more particularly to a diagnostic technique for a sensor for detecting the rotational position of a crankshaft.

  A general internal combustion engine is provided with a sensor for detecting the rotational position and rotational speed of the crankshaft and camshaft in order to operate in an optimal combustion state. These sensors are very important in controlling the internal combustion engine. Therefore, in order to ensure the soundness of these sensors, whether or not an abnormality has occurred is diagnosed during operation of the internal combustion engine.

  When such a diagnosis is performed, it may be erroneously determined as abnormal due to noise or the like. Therefore, a diagnostic method has been proposed that can increase noise tolerance and determine with high accuracy. For example, Japanese Patent Laying-Open No. 2005-055289 (Patent Document 1) detects the rotational position of the output shaft of an internal combustion engine for the purpose of preventing erroneous determination of abnormality based on erroneous calculation of engine speed due to noise. An abnormality determination device that determines abnormality of a rotational position detection sensor that performs the above is disclosed.

On the other hand, a valve that can change the opening / closing timing of the intake valve in each cylinder in order to realize an optimal combustion state according to the operating state of the internal combustion engine (high load and low load, low rotation range and high rotation range, etc.) A variable timing mechanism is often employed. For example, Japanese Patent Laid-Open No. 2001-263152 (Patent Document 2) discloses a diagnostic device for a rotational position detection sensor system in an internal combustion engine (an engine with a variable valve timing mechanism) having a variable valve timing mechanism. According to this diagnostic apparatus, the ratio between the count value of the input pulse from the first rotational position detection sensor that outputs the crank pulse and the input pulse from the second rotational position detection sensor that outputs the cam position pulse is calculated. When the ratio is outside the specified value, it is diagnosed that the rotational position detection sensor system is abnormal.
JP 2005-055289 A JP 2001-263152 A JP 2000-054869 A

  The variable valve timing mechanism often employs a configuration in which the valve timing is varied using hydraulic pressure, but such hydraulic pressure is often generated by an oil pump that operates by receiving the rotational driving force of the internal combustion engine. . Therefore, in a transient state such as when the internal combustion engine is started (during cranking), sufficient oil pressure cannot be obtained, and the variable valve timing mechanism is likely to become unstable. As a result, the rotation of the camshaft connected to the variable valve timing mechanism fluctuates, and chattering or the like may occur in the detection signal from the sensor for detecting the rotational position of the camshaft.

  Due to such chattering of the detection signal, there is a problem that the conventional abnormality diagnosis technique erroneously determines that a sensor abnormality has occurred.

  The present invention has been made to solve such a problem, and an object thereof is to determine whether or not an abnormality has occurred in a sensor that detects a rotational position in an internal combustion engine having a variable valve timing mechanism. It is an object of the present invention to provide a vehicle control device that can suppress erroneously determining that an abnormality has occurred.

  A control apparatus for a vehicle according to an aspect of the present invention includes an internal combustion engine, and the internal combustion engine is configured to be rotatable, a camshaft that rotates in accordance with the rotation of the crankshaft, and a rotation of the camshaft. An air valve that opens and closes the air passage leading to the combustion chamber, a variable valve timing mechanism that can change the opening and closing timing of the air valve by changing the rotation phase of the camshaft with respect to the crankshaft, and detects the rotational position of the crankshaft A first detector and a second detector for detecting the rotational position of the camshaft are included. The control device according to this aspect includes: a first determination unit that determines whether or not an abnormality has occurred in the first detection unit based on a comparison between a detection result by the first detection unit and a detection result by the second detection unit; The second determination means for determining whether or not the variable timing mechanism is in a swaying state, and the determination result by the first determination means is invalid during a period in which the second determination means determines that the variable valve timing mechanism is in a swaying state. And invalidating means.

  According to this invention, the variable valve timing mechanism is shaken when determining whether or not an abnormality has occurred in the first detection unit based on the comparison result between the detection result by the first detection unit and the detection result by the second detection unit. It is determined whether or not it is in a state. If the variable valve timing mechanism is in a swaying state, the determination result by the first determination means is invalidated. For this reason, disturbance such as chattering occurs in the detection result by the second detection unit due to the fluctuation of the variable valve timing mechanism, and even if an erroneous determination is made by the first determination unit, it is not output. Therefore, it is possible to suppress erroneously determining that an abnormality has occurred when determining whether or not an abnormality has occurred in the sensor that detects the rotational position.

  Preferably, the vehicle further includes at least one rotating electric machine that is mechanically connected to a crankshaft of the internal combustion engine, and the rotating electric machine includes a rotor portion that is arranged to be driven according to the rotation of the crankshaft, And a third detector for detecting the rotational speed. Then, the second determination means is an estimation means for estimating the amount of change in the rotational position of the crankshaft based on the detection result by the third detection section, and a comparison result between the estimation result by the estimation means and the detection result by the second detection section. And a third determining means for determining whether or not the variable valve timing mechanism is in a swaying state.

  More preferably, the at least one rotating electric machine includes two rotating electric machines connected to the crankshaft via a planetary gear mechanism, and the estimating means detects each of the two rotating electric machines by a third detection unit. Based on the result, the amount of change in the rotational position of the crankshaft is estimated.

  Preferably, the second determination means determines whether or not the variable valve timing mechanism is in a swinging state when the internal combustion engine is cranking.

  More preferably, the second determination means determines whether or not the variable valve timing mechanism is in a swaying state when the stop time from the previous stop of the internal combustion engine to the current cranking exceeds a predetermined threshold time. Judging.

  Preferably, the control device according to this aspect further includes fuel supply prohibiting means for prohibiting the supply of fuel to the internal combustion engine during a period in which the determination result by the first determination means is invalidated by the invalidating means.

  According to the present invention, in an internal combustion engine equipped with a variable valve timing mechanism, a vehicle that can suppress erroneously determining that an abnormality has occurred when determining whether or not an abnormality has occurred in a sensor that detects a rotational position. Can be realized.

  Embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

(Overall configuration of vehicle)
FIG. 1 is a schematic diagram of a vehicle 1 provided with a control device 2 according to an embodiment of the present invention.

  Referring to FIG. 1, a vehicle 1 is a hybrid vehicle as an example, and includes an internal combustion engine (engine) 100, a damper device 114, a power split mechanism 120, a first motor generator 116, and a second motor generator 122. , Control device 2, power control unit (PCU) 60, and power storage device 70.

  An output shaft that rotates integrally with the crankshaft of the internal combustion engine 100 that operates by the combustion of fuel is connected to the power split mechanism 120 via a spring-type damper device 114. The damper device 114 absorbs rotational fluctuations of the internal combustion engine 100.

  Power split device 120 is formed of a single pinion type planetary gear mechanism, and includes carrier 120 c connected to damper device 114, sun gear 120 s connected to motor shaft 124 of first motor generator 116, and rotor of second motor generator 122. It is composed of three rotating elements of a ring gear 120r connected to the portion 122r. The internal combustion engine 100, the damper device 114, the power split mechanism 120, and the first motor generator 116 are arranged on the same axis in the axial direction, and the second motor generator 122 includes the damper device 114 and the power split mechanism 120. It is arranged concentrically on the outer peripheral side of the.

  That is, the crankshaft (output shaft) of internal combustion engine 100 is mechanically connected to motor generators 116 and 122 via power split mechanism 120. The internal combustion engine 100, the first motor generator 116, and the second motor generator 122 rotate while maintaining a certain relationship shown in an alignment chart described later. Here, as the internal combustion engine 100 is driven to rotate, the rotor portions 116r and 122r rotate.

  Furthermore, output member 118 of power split mechanism 120 is integrally fixed to rotor portion 122r of second motor generator 122, and is connected to ring gear 120r of power split mechanism 120 via the rotor portion 122r. . An output gear 126 is provided on the output member 118, and a bevel gear type differential gear 80 is decelerated and rotated via the large gear 130 and the small gear 132 of the intermediate shaft 128, and a driving force is applied to each driving wheel 90. Distributed.

  Resolvers 117 and 119 for detecting respective rotational speeds MRN1 and MRN2 are provided in rotor portions 116r and 122r of motor generators 116 and 122, respectively. Rotational speeds MRN1 and MRN2 detected by resolvers 117 and 119 are output to control device 2.

  Motor generators 116 and 122 are electrically connected to power storage device 70 via a power control unit (PCU) 60. The power storage device 70 is a chargeable / dischargeable DC power supply device, and includes, for example, a secondary battery such as a nickel metal hydride battery or a lithium ion battery, or an electric double layer capacitor. Power control unit 60 includes independent power conversion units (for example, inverter devices) electrically connected to motor generators 116 and 122, respectively, and exchanges power between power storage device 70 and motor generators 116 and 122, respectively. To control. Specifically, the power control unit 60 supplies the electric power from the power storage device 70 to the motor generator to operate the motor generator as an electric motor. On the other hand, when the motor generator operates as a generator, the motor The electric power from the generator is returned (regenerated) to the power storage device 70.

  The control device 2 includes an electronic control unit (ECU) including a CPU and a memory area including a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The driving torque and rotational speed generated by the internal combustion engine 100, the first motor generator 116, and the second motor generator 122 are optimally controlled.

  In particular, in the present embodiment, the control device 2 includes a so-called sensor diagnostic function that determines whether or not an abnormality has occurred in a sensor that detects a rotational position in the internal combustion engine 100 as will be described later.

(Configuration of internal combustion engine)
FIG. 2 is a schematic configuration diagram of the internal combustion engine 100 according to the present embodiment.

  Referring to FIG. 2, an internal combustion engine 100 reciprocates between a crankshaft 36 configured to be rotatable as an output shaft of the internal combustion engine 100, a cylinder 30 provided in a cylinder block, and a cylinder 30 serving as a combustion chamber. It includes a moving piston 32 and a connecting rod 34 connecting the piston 32 and the crankshaft 36. In addition, the internal combustion engine 100 is opened and closed by an intake camshaft 20 (hereinafter also simply referred to as “camshaft”), a cam 26 attached to the camshaft 20, and pushed down by the cam 26 in accordance with the rotation of the camshaft 20. And an intake valve 28. The intake valve 28 is an air valve for opening and closing an air passage leading from the intake path to the combustion chamber.

  The camshaft 20 is mechanically connected by a timing chain 40 to a sprocket wheel 18 attached to one end of the camshaft 20 and a sprocket wheel 38 attached to one end of the crankshaft 36. As a result, the camshaft 20 rotates in conjunction with the rotation of the crankshaft 36.

  The internal combustion engine 100 further includes a variable valve timing (VVT) mechanism 200 that can change the opening / closing timing of the intake valve 28 by changing the rotational phase of the camshaft 20 relative to the crankshaft 36. The variable valve timing mechanism 200 is controlled by hydraulic oil from an oil control valve (OCV) 14 connected via a hydraulic pipe 15. Further, the variable valve timing mechanism 200 includes a housing fixed to the sprocket wheel 18 and a rotor fixed to the camshaft 20 (none is shown). Then, the oil control valve 14 supplies hydraulic oil to the advance chamber or the retard chamber existing between the housing portion and the vane portion in accordance with the timing control signal VT from the control device 2, so that the camshaft The rotational phase of the 20 crankshafts 36 is continuously changed.

  The internal combustion engine 100 further includes a fuel pump drive cam 24 attached to the camshaft 20 and a fuel pump 27 driven by the rotation of the camshaft 20. The control device 2 outputs a control signal SP to control fuel pressure of the fuel pump 27 and fuel supply prohibition (fuel cut).

  The internal combustion engine 100 further includes a crank angle sensor 10 that detects the rotational position of the crankshaft 36, and a cam that detects the rotation angle of the camshaft 20 by detecting the rotation of the protrusion provided on the end surface of the camshaft 20. Angle sensor 22. Then, the crank angle sensor 10 and the cam angle sensor 22 output the rotational speed signal NE and the cam angle signal CP to the control device 2, respectively. The control device 2 adjusts the timing control signal VT so that the rotational phase between the rotational speed signal NE and the cam angle signal CP becomes a predetermined value according to the driving operation of the driver and the operating state of the internal combustion engine. To do.

(Crank angle sensor)
FIG. 3 is a view showing a state in which the crank angle sensor 10 is attached.

  Referring to FIG. 3, the crank angle sensor 10 is disposed close to the outer peripheral surface of the crankshaft timing rotor 11 attached to one end of the crankshaft 36 in parallel with the sprocket wheel 38. A predetermined number of signal teeth (for example, 12 teeth for every 30 ° CA) are formed on the outer peripheral surface of the crankshaft timing rotor 11. The crank angle sensor 10 is an electromagnetic pickup sensor, and the magnetic flux passing through the coil portion of the crank angle sensor 10 is changed by a change in the gap distance (air gap) between the crank teeth and the signal teeth accompanying the rotation of the crankshaft timing rotor 11. The counter electromotive voltage is generated in the coil portion by being increased or decreased. Then, an AC signal (pulse signal) corresponding to the change in the counter electromotive voltage is output as the rotation speed signal NE. Here, “CA” means “crankshaft rotation angle”.

  3 shows the crankshaft timing rotor 11 in which signal teeth are formed over the entire circumference, the rotation angle corresponding to the top dead center is such that the top dead center of the piston 32 (FIG. 2) can be detected more accurately. You may use the crankshaft timing rotor comprised so that the signal tooth of a position might be missing.

(Cam angle sensor)
FIG. 4 is a view showing a mounting state of the cam angle sensor 12.

  Referring to FIG. 4, cam angle sensor 12 detects a protrusion provided on end surface 13 of camshaft 20 opposite to the side on which valve timing variable mechanism 200 is disposed. Similar to the crank angle sensor 10 described above, the cam angle sensor 12 is also an electromagnetic pickup sensor, and is based on a change in the gap distance (air gap) between each protrusion and the cam angle sensor 12 as the cam shaft 20 rotates. The cam angle signal CP is output using the magnetic flux change. As an example, six protrusions are arranged on the end face 13 at non-uniform intervals of 60-60-180-120-120-180 ° CA.

  FIG. 4 shows an exhaust camshaft 21 that is mechanically coupled with the camshaft 20 by a timing chain 40 and rotates to open and close the exhaust valve.

(Sensor diagnostic function)
In the present embodiment, the control device 2 compares the rotation speed signal NE, which is the detection result by the crank angle sensor 10, with the cam angle signal CP, which is the detection result by the cam angle sensor 12, so that the crank angle sensor 10 Determine whether an abnormality has occurred. More specifically, the control device 2 specifies a period corresponding to four rotations of the crankshaft 36 (360 × 4 = 1440 ° CA) based on the input cam angle signal CP, and inputs it within each period. It is determined whether or not the count number of the rotation speed signal NE to be coincided with a specified value (48 pulses per four rotations in the present embodiment).

FIG. 5 is a block diagram showing a control structure related to the sensor diagnosis function in the control device 2.
Referring to FIG. 5, the control structure of control device 2 includes counter units 302 and 304 and a comparison unit 306.

  The counter unit 302 counts the pulse change of the cam angle signal CP given from the cam angle sensor 12, and the count value corresponds to a value corresponding to four rotations (1440 ° CA) of the crankshaft 36 (in this embodiment, 12 times), a reset signal is output to the counter unit 304. The counter unit 304 counts the number of pulses of the rotation speed signal NE given from the cam angle sensor 22. Then, when the reset signal is given from the counter unit 302, the counter unit 304 outputs the count value at that time to the comparison unit 306, and further resets its own count value to zero. Therefore, the counter unit 304 outputs the count value of the rotation speed signal NE for each period corresponding to four rotations of the crankshaft 36 determined based on the cam angle signal CP. The comparison unit 306 compares the count value output from the counter unit 304 with the threshold value α, and if both do not match, generates an abnormality determination signal FLT indicating an abnormality in the crank angle sensor 10. In this way, it is determined whether or not an abnormality has occurred in the crank angle sensor 10.

  The control structure of the control device 2 further includes a mask unit 308 and a shaking state determination unit 300. As will be described later, these blocks are for preventing erroneous determination that the crank angle sensor 10 is abnormal when the variable valve timing mechanism 200 is in a swaying state.

  Specifically, the mask unit 308 is inserted on the output side of the comparison unit 306 and masks the output from the comparison unit 306 in response to the mask signal MSK from the sway state determination unit 300, thereby determining abnormality. The signal FLT is invalidated. The swing state determination unit 300 determines whether or not the variable valve timing mechanism 200 is in a swing state, and outputs a mask signal MSK when the variable valve timing mechanism 200 is in a swing state.

(Valve timing variable mechanism)
First, the configuration of the variable valve timing mechanism 200 and the shaking state thereof will be described.

FIG. 6 is a perspective view of variable valve timing mechanism 200 according to the present embodiment.
Referring to FIG. 6, the variable valve timing mechanism 200 includes a rotor 220 in which a vane portion 221 is formed, and a housing 210 that accommodates the rotor 220. The rotor 220 is fixed to the camshaft 20 and rotates together with the camshaft 20. On the other hand, the housing 210 is fixed to the sprocket wheel 18 on which the timing chain 40 (FIG. 2) is hung, and rotates together with the sprocket wheel 18.

  Further, the housing 210 is formed with an advance chamber 211 and a retard chamber 212 which are hydraulic chambers. The advance chamber 211 and the retard chamber 212 are partitioned by a vane portion 221. The advance chamber 211 and the retard chamber 212 are each independently connected to an oil passage leading to the oil control valve 14 (FIG. 2). When hydraulic oil is supplied to the advance chamber 211 or the retard chamber 212 through the oil passage, the vane part 121 moves in the housing 210 while maintaining the airtightness between the advance chamber 211 and the retard chamber 212, The volumes of the advance chamber 211 and the retard chamber 212 are changed. At this time, when the camshaft 20 rotates together with the rotor 220, the rotational phase of the camshaft 20 relative to the crankshaft 36 (FIG. 2) changes.

  When the camshaft 20 is rotated in the advance direction indicated by the arrow 201 (the same direction as the rotation direction of the camshaft 20), the advance chamber 211 is enlarged and the retard chamber 212 is reduced. On the other hand, when the camshaft 20 is rotated in the retarded direction indicated by the arrow 202 (the direction opposite to the rotational direction of the camshaft 20), the advance chamber 211 is reduced and the retard chamber 212 is increased. The hydraulic pressure of the hydraulic oil supplied to the advance chamber 211 and the retard chamber 212 is generated by an oil pump (not shown) that is connected to the crankshaft 36 (FIG. 2) and rotates.

  Furthermore, in variable valve timing mechanism 200 according to the present embodiment, a lock pin for fixing vane portion 221 at a predetermined position (for example, the most retarded state) is provided inside vane portion 221 when internal combustion engine 100 is stopped. It is done.

  FIG. 7 is a cross-sectional view showing the internal structure of the vane portion 221. FIG. 7A shows a state when the internal combustion engine 100 is stopped. FIG. 7B shows a state where the internal combustion engine 100 is operating. FIG. 7C shows a state in which the variable valve timing mechanism 200 can be shaken.

  Referring to FIG. 7, a lock pin 232 is arranged inside the vane portion 221 so as to be movable along the central axis Ax (FIG. 6) of the camshaft 20 and biased toward the housing 210 by a spring 230. Is provided. On the other hand, a lock hole 234 is formed in the housing 210 at a position where the lock pin 232 can be fitted when the vane portion 221 is in the most retarded state. Further, the lock pin 232 is formed so as to generate a force that overcomes the spring force of the spring 230 by receiving the hydraulic pressure of the hydraulic oil supplied to the advance chamber 211 and the retard chamber 212.

  When the internal combustion engine 100 is stopped, the supply of hydraulic oil is also stopped. Therefore, as shown in FIG. 7A, the vane portion 221 is in the most retarded state, and the lock pin 232 is moved by the spring force of the spring 230. The lock hole 234 is fitted. Therefore, the vane part 221 is fixed in the most retarded state. When the internal combustion engine 100 starts to operate, supply of the hydraulic pressure from the oil pump is started, so that the lock pin 232 is pushed back toward the vane portion 221 as shown in FIG. Is released from the mating. Therefore, the vane part 221 becomes rotatable.

  However, as shown in FIG. 7C, the lock pin 232 biased by the spring 230 comes into contact with the housing 210 at a position other than the lock hole 234 due to vibration when the internal combustion engine 100 is stopped, etc. 234 may not fit. In such a case, the vane portion 221 is not substantially fixed, and the vane portion 221 is caused by vibrations generated during cranking (starting) for rotating the crankshaft 36 to start the internal combustion engine 100. Fluctuates in an oscillating manner toward the retard side and the advance side. In particular, when the stop time of the internal combustion engine 100 is long and the advance chamber 211 and the retard chamber 212 are not filled with hydraulic oil, the amplitude tends to increase because there is nothing to prevent the vane portion 221 from shaking. .

  Due to this fluctuation, the rotational position of the camshaft 20 fixed to the vane portion 221 also fluctuates in a vibrational manner. Therefore, the cam angle sensor 12 repeatedly detects the same protrusion in a short time, and an irregular pulse component, so-called chattering, occurs in the cam angle signal CP output from the cam angle sensor 12. As a result, the counter unit 302 (FIG. 5) outputs a reset signal before the crankshaft 36 actually rotates four times, the count value of the rotation speed signal NE becomes smaller than the original value, and the crank angle sensor 10 It is erroneously determined that an abnormality has occurred.

  As described above, when the variable valve timing mechanism 200 is in a swaying state, the abnormality determination signal FLT indicating the occurrence of abnormality in the crank angle sensor 10 is erroneously output. Therefore, in the present embodiment, such a fluctuation state of the variable valve timing mechanism 200 is detected, and mask processing is performed so that the abnormality determination signal FLT is not erroneously output.

(Configuration of shaking state judgment unit)
In the present embodiment, as an example, the rotational state of crankshaft 36 is estimated based on rotational speeds MRN1 and MRN2 of motor generators 116 and 122 (FIG. 1), and cam angle signal CP from cam angle sensor 22 and the estimated value are estimated. The fluctuation state of the variable valve timing mechanism 200 is detected by comparison with the rotated state.

  Referring to FIG. 5 again, the sway state determination unit 300 includes a crank angle estimation unit 320, a crank angle change amount calculation unit 322, comparison units 324 and 328, a timer unit 326, and a logical product unit 330. Including.

  Crank angle estimation unit 320 estimates estimated crank angle CRK of crankshaft 36 based on rotational speeds MRN1 and MRN2 of motor generators 116 and 122. Specifically, the crank angle estimation unit 320 estimates the estimated crank angle CRK of the crankshaft 36 from the collinear relationship according to the reduction ratio between the elements of the planetary gear mechanism constituting the power split mechanism 120. The

  FIG. 8 is a collinear diagram showing the rotational speed relationship among the internal combustion engine 100, the first motor generator 116 and the second motor generator 122.

  In the collinear chart shown in FIG. 8, the horizontal axis defines the distance according to the reduction ratio between each element of the planetary gear mechanism, and the vertical axis defines the rotational speed of each element. In this alignment chart, the rotational speeds of the first motor generator 116, the internal combustion engine 100, and the second motor generator 122 connected to the sun gear 120s, the carrier 120c, and the ring gear 120r, respectively, are always arranged in a straight line. Therefore, if the rotational speeds MRN1 and MRN2 of the first and second motor generators and the reduction ratio between the elements of the planetary gear mechanism are known, the rotational speed of the internal combustion engine 100 can be calculated.

  Therefore, the crank angle estimation unit 320 calculates the estimated crank angle CRK based on the rotational speeds MRN1 and MRN2 output from the resolvers 117 and 119 (FIG. 1) according to the reduction gear ratio of the planetary gear mechanism stored in advance. The estimated crank angle CRK is output to the crank angle change amount calculation unit 322. In the present embodiment, the estimated crank angle CRK is output in the range of 0 to 720 ° CA.

Each signal waveform obtained as described above will be described with reference to FIG.
FIG. 9 is a diagram illustrating a time waveform of each signal. FIG. 9 shows a time waveform for a period corresponding to four rotations of the crankshaft 36.

  Since the crank angle sensor 10 detects the rotational state of the crankshaft 36 using the crankshaft timing rotor 11 in which signal teeth are formed every 30 ° CA as shown in FIG. 3, the rotational speed signal NE is It becomes a pulse waveform with an interval of 30 ° CA as shown in 9 (a).

  The cam angle sensor 22 detects the rotational state of the camshaft 20 using the end face 13 on which six protrusions are arranged at non-uniform intervals of 60-60-180-120-120-180 ° CA. Therefore, as shown in FIG. 9B, the cam angle signal CP has a pulse waveform corresponding to the angular interval between adjacent protrusions. The cam angle signal CP shown in FIG. 9B is output as a state pulse signal in which “high level” and “low level” are alternately switched in response to the detection of the protrusion, but FIG. As shown in FIG. 6, a pulse having a short time width may be output in response to detection of the protrusion.

  As shown in FIG. 9D, the estimated crank angle CRK calculated by the crank angle estimation unit 320 has a saw-tooth waveform that forms one cycle at 720 ° CA.

  On the other hand, FIG. 9C shows an example of the cam angle signal CP in which chattering 400 occurs. As described above, when the variable valve timing mechanism 200 is in a swaying state, the cam angle sensor 12 repeatedly detects the same protrusion in a short time. As a result, in the cam angle signal CP, pulses are continuously generated in a short time. The counter unit 302 (FIG. 5) counts as two pulses even in such chattering 400, which causes an erroneous determination.

  Therefore, the crank angle change amount calculation unit 322 and the comparison unit 324 detect such chattering 400 as a condition for determining whether or not the valve timing variable mechanism is in a swaying state.

FIG. 10 is a diagram showing an outline of the processing in the crank angle change amount calculation unit 322.
As shown in FIG. 10A, the cam angle sensor CP receives a pulsed cam angle signal CP from the cam angle sensor 12. Here, the pulse interval of the cam angle signal CP corresponds to the interval between the protrusions provided on the end face 13 shown in FIG. Since the protrusions on the end face 13 according to the present embodiment are set at three types of intervals of 60, 120, and 180 ° CA, the estimated crank is generated while two consecutive pulses in the cam angle signal CP are generated. The angle CRK should change at least greater than 60 ° CA.

  On the other hand, since the time interval between two consecutive pulses due to chattering is shortened, the amount of change in the estimated crank angle CRK is smaller than 60 ° CA. Therefore, by calculating the change amount of the estimated crank angle CRK, that is, the rotation position change amount at every pulse generation timing of the cam angle signal CP, it is possible to determine whether or not chattering has occurred in the cam angle signal CP.

  That is, as shown in FIG. 10 (a), when the cam angle signal CP pulse is generated at times t1 and t2, the crank angle change amount calculation unit 322 performs the operation from time t1 to time t2 (time interval Δt). An angle change amount ΔCRK of the estimated crank angle CRK is calculated (FIG. 10B).

  Referring to FIG. 5 again, the angle change amount ΔCRK calculated by the crank angle change amount calculation unit 322 is output to the comparison unit 324, and it is determined whether or not it is smaller than the minimum angle interval ΔCPmin. The comparison unit 324 activates the output to the AND unit 330 when the angle change amount ΔCRK is smaller than the minimum angle interval ΔCPmin. The minimum angle interval ΔCPmin is determined so as not to exceed the minimum angle between the protrusions detected by the cam angle sensor 12.

  Then, the AND unit 330 supplies the mask signal MSK to the comparison unit 306 when the output from the comparison unit 324 is activated and both the first and second condition signals described later are activated. Here, the logical product unit 330 includes a first condition signal that is activated when no hydraulic oil remains in the advance chamber 211 and the retard chamber 212 (FIG. 6) of the variable valve timing mechanism 200, and the internal combustion engine. A second condition signal is provided that is activated when engine 100 is cranking. These condition signals are used for determining the fluctuation state of the variable valve timing mechanism 200 with higher accuracy.

  In other words, if the advance chamber 211 and the retard chamber 212 are filled with hydraulic oil, the vane portion 221 cannot rotate freely and will not be in a swaying state. Therefore, in order to determine the fluctuation state of the variable valve timing mechanism 200 with higher accuracy, the variable valve timing mechanism 200 is in the fluctuation state only when no hydraulic oil remains in the advance chamber 211 and the retard chamber 212. Is determined (first condition signal).

  Specifically, the timer unit 326 and the comparison unit 328 that generate the first condition signal determine whether hydraulic oil remains in the advance chamber 211 and the retard chamber 212 based on the stop time of the internal combustion engine 100. Judging. That is, when the internal combustion engine 100 is stopped, the hydraulic oil in the advance chamber 211 and the retard chamber 212 is returned to an oil pan provided in the lower portion of the internal combustion engine 100 according to gravity. Since the return of the hydraulic oil to the oil pan proceeds with time, by measuring the stop time from when the internal combustion engine 100 is stopped to cranking, how much hydraulic oil is in the advance chamber 211 and the retard chamber It can be estimated whether or not 212 remains.

  Therefore, the timer unit 326 starts time integration every time the operation of the internal combustion engine 100 is stopped, and outputs the accumulated stop time to the comparison unit 328. The comparison unit 328 compares the stop time accumulated by the timer unit 326 with the threshold time β estimated that sufficient hydraulic oil does not remain in the advance chamber 211 and the retard chamber 212, and accumulates them. If the stop time exceeds the threshold time β, the output to the AND unit 330 is activated.

  Further, since the variable valve timing mechanism 200 is generated at the time of starting when the hydraulic oil pressure cannot be sufficiently secured, whether or not the variable valve timing mechanism 200 is in a swaying state only when the internal combustion engine 100 is cranking. Is determined (second condition signal).

  Further, the logical product unit 330 performs the fuel injection prohibition (control signal SP) for prohibiting the fuel supply in the internal combustion engine 100 during the period in which the mask signal MSK is output to the comparison unit 306 in the fuel pump 27 (FIG. To 2). This is because the diagnostic function of the crank angle sensor 10 is invalidated during the period in which the mask signal MSK is being output, so that the soundness of the crank angle sensor 10 cannot be ensured.

  The internal combustion engine 100 cannot be started when the fuel supply is prohibited, but the lock pin 232 is fitted into the lock hole 234 or the hydraulic oil is supplied to the advance chamber 211 and the retard chamber 212 by the cranking operation. The shaking state of the variable valve timing mechanism 200 is resolved relatively quickly (about several hundred milliseconds to several seconds). Therefore, in practice, a driver or the like does not feel stress due to prohibition of fuel supply to the internal combustion engine 100.

(Processing flow)
FIG. 11 is a flowchart showing a processing procedure related to prevention of erroneous determination for crank angle sensor 10 according to the present embodiment.

  Referring to FIG. 11, it is determined whether or not variable valve timing mechanism 200 is in a swaying state (steps S10 to S20). More specifically, it is first determined whether or not the internal combustion engine 100 is cranking (step S10). If the internal combustion engine 100 is being cranked (YES in step S10), a stop time determination subroutine described later is executed (step S12), and the advance chamber 211 and the retard chamber 212 of the variable valve timing mechanism 200 are sufficient. It is determined whether or not there is any remaining hydraulic oil (step S14). When sufficient hydraulic fluid remains in the advance chamber 211 and the retard chamber 212 of the variable valve timing mechanism 200 (YES in step S14), a chattering determination subroutine described later is executed (step S16). It is determined whether chattering has occurred in the cam angle signal CP from the cam angle sensor 12 (step S18). If chattering has occurred in the cam angle signal CP from the cam angle sensor 12 (YES in step S18), it is determined that the variable valve timing mechanism 200 is in an oscillating state (step S20).

  When it is determined that the variable valve timing mechanism 200 is in a swaying state (step S20), a mask signal MSK is issued and the abnormality determination signal FLT is invalidated (step S22). Furthermore, fuel injection prohibition is given to the fuel pump 27, and fuel supply in the internal combustion engine 100 is prohibited (step S24). Processing is then returned to the beginning.

  On the other hand, if any one of steps S10, S14, and S18 is NO, it is determined that the valve timing variable mechanism 200 is not in a swaying state (step S26), and the generated mask signal MSK is canceled. Abnormality determination signal FLT is validated (step S28). If the mask signal MSK has not been issued, the process of step S28 is omitted. Processing is then returned to the beginning.

  FIG. 12 is a flowchart showing a processing procedure according to the stop time determination subroutine executed in step S12 of FIG.

  Referring to FIG. 12, the stop time accumulated from the time when internal combustion engine 100 is stopped to the present time is read (step S100). Then, it is determined whether or not the read accumulated time exceeds the threshold time β (step S102). If the accumulated time exceeds the threshold time β (YES in step S102), it is determined that sufficient hydraulic oil does not remain in the advance chamber 211 and the retard chamber 212 of the variable valve timing mechanism 200. Then, the process returns to the main routine shown in FIG.

  When the accumulated time does not exceed the threshold time β (NO in step S102), it is determined that sufficient hydraulic oil remains in the advance chamber 211 and the retard chamber 212 of the variable valve timing mechanism 200. Then, the process returns to the main routine shown in FIG.

  FIG. 13 is a flowchart showing a processing procedure related to the chattering determination subroutine executed in step S16 of FIG.

  Referring to FIG. 13, estimated crank angle CRK of crankshaft 36 is estimated based on rotation speeds MRN1 and MRN2 of motor generators 116 and 122 (step S200).

  An angular change amount ΔCRK of the estimated crank angle CRK between two consecutive pulses of the cam angle signal CP (time interval Δt) is calculated (step S202). Then, it is determined whether or not the calculated angle change amount ΔCRK is smaller than the minimum angle interval ΔCPmin (step S204).

  If the angle change amount ΔCRK is smaller than the minimum angle interval ΔCPmin (YES in step S204), it is determined that chattering has occurred in the cam angle signal CP (step S206), and the main routine shown in FIG. Return. On the other hand, if angle change amount ΔCRK is not smaller than minimum angle interval ΔCPmin (NO in step S204), it is determined that chattering has not occurred in cam angle signal CP (step S208), and the main routine shown in FIG. The process returns to.

  In the present embodiment, the crank angle sensor 10 corresponds to a “first detector”, the cam angle sensor 22 corresponds to a “second detector”, and the resolvers 117 and 119 correspond to “third detectors”. The counter units 302 and 304 and the comparison unit 306 correspond to the “first determination unit”, the swing state determination unit 300 corresponds to the “second determination unit”, the crank angle estimation unit 320, and the crank angle change amount calculation unit 322. The comparison unit 324 corresponds to “third determination unit”, the mask unit 308 corresponds to “invalidation unit”, and the first motor generator 116 and the second motor generator 122 correspond to “rotating electric machine”.

  According to the present embodiment, the rotation speed signal NE from the crank angle sensor 10 and the cam angle signal CP from the cam angle sensor 22 are compared to determine whether or not an abnormality has occurred in the crank angle sensor 10. Then, it is determined whether or not the variable valve timing mechanism 200 is in an oscillating state. When it is determined that the variable valve timing mechanism 200 is in a swaying state, the abnormality determination signal FLT indicating the occurrence of abnormality in the crank angle sensor 10 is invalidated.

  Therefore, chattering or the like occurs in the cam angle signal CP from the cam angle sensor 22 due to the fluctuation of the variable valve timing mechanism 200, and thus it is possible to suppress the abnormality determination signal FLT being erroneously output.

  In the present embodiment, a hybrid vehicle including two motor generators has been exemplified. However, if the vehicle includes an internal combustion engine having a variable valve timing mechanism and a configuration that can determine the oscillation state of the variable valve timing mechanism, It is not limited to hybrid cars. For example, the number of chattering occurrences is determined by comparing the gear speed of an automatic transmission connected to the output shaft (crankshaft) of an internal combustion engine with a cam angle signal from a cam angle sensor. Based on this, the state of fluctuation of the variable valve timing mechanism may be determined.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic diagram of the vehicle provided with the control apparatus according to embodiment of this invention. It is a schematic block diagram of the internal combustion engine according to the present embodiment. It is a figure which shows the attachment state of a crank angle sensor. It is a figure which shows the attachment state of a cam angle sensor. It is a block diagram which shows the control structure which concerns on the sensor diagnostic function in a control apparatus. It is a perspective view of the valve timing variable mechanism according to the present embodiment. It is sectional drawing which shows the internal structure of a vane part. It is a collinear diagram which shows the relationship of the rotational speed between an internal combustion engine, a 1st motor generator, and a 2nd motor generator. It is a figure which shows the time waveform of each signal. It is a figure which shows the outline of the process in a crank angle variation | change_quantity calculation part. It is a flowchart which shows the process sequence which concerns on prevention of misjudgment about the crank angle sensor according to this Embodiment. It is a flowchart which shows the process sequence which concerns on the stop time determination subroutine performed by step S12 of FIG. It is a flowchart which shows the process sequence which concerns on the chattering determination subroutine performed by step S16 of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle, 2 Control apparatus, 10 Crank angle sensor, 11 Crankshaft timing rotor, 12 Cam angle sensor, 13 End surface, 14 Oil control valve (OCV), 15 Hydraulic piping, 18 Sprocket wheel, 20 Intake camshaft (camshaft) , 21 exhaust camshaft, 22 cam angle sensor, 24 fuel pump drive cam, 26 cam, 27 fuel pump, 28 intake valve, 30 cylinder, 32 piston, 34 connecting rod, 36 crankshaft, 38 sprocket wheel, 40 timing chain, 60 power control unit (PCU), 70 power storage device, 80 differential gear, 90 driving wheel, 100 internal combustion engine, 114 damper device, 116 first motor generator 116r rotor section, 117 resolver, 118 output member, 120 power split mechanism, 120c carrier, 120s sun gear, 120r ring gear, 121 vane section, 122 second motor generator, 122r rotor section, 124 motor shaft, 126 output gear, 128 intermediate shaft, 130 large gear, 132 small gear, 200 valve timing variable mechanism (VVT), 201, 202 arrow, 210 housing, 211 advance chamber, 212 retard chamber, 220 rotor, 221 vane portion, 232 lock pin, 234 Lock hole, 300 Oscillating state determination unit, 302, 304 counter unit, 306, 324, 328 comparison unit, 308 mask unit, 320 crank angle estimation unit, 322 crank angle change amount calculation unit, 326 timer unit, 330 logical product unit 4 00 Chattering.

Claims (6)

A control device for a vehicle having an internal combustion engine,
The internal combustion engine
A crankshaft configured to be rotatable;
A camshaft that rotates according to the rotation of the crankshaft;
An air valve that opens and closes an airway leading to the combustion chamber according to the rotation of the camshaft;
A variable valve timing mechanism configured to change the opening / closing timing of the air valve by changing the rotational phase of the camshaft relative to the crankshaft;
A first detector for detecting a rotational position of the crankshaft;
A second detector for detecting the rotational position of the camshaft,
The controller is
First determination means for determining whether or not an abnormality has occurred in the first detection unit based on a comparison between a detection result by the first detection unit and a detection result by the second detection unit;
Second determination means for determining whether or not the valve timing variable mechanism is in a swaying state;
A vehicle control apparatus comprising: invalidating means for invalidating a determination result by the first determination means during a period in which the second determination means determines that the variable valve timing mechanism is in a swaying state. The vehicle further includes at least one rotating electrical machine mechanically connected to the crankshaft of the internal combustion engine,
The rotating electric machine is
A rotor portion arranged to be driven according to the rotation of the crankshaft;
A third detection unit for detecting the rotational speed of the rotor unit,
The second determination means includes
Estimation means for estimating a rotational position change amount of the crankshaft based on a detection result by the third detection unit;
3. A third determination unit that determines whether or not the variable valve timing mechanism is in a swaying state based on a comparison result between an estimation result by the estimation unit and a detection result by the second detection unit. The vehicle control device described in 1. The at least one rotating electric machine includes two rotating electric machines connected to the crankshaft via a planetary gear mechanism,
The vehicle control device according to claim 2, wherein the estimation unit estimates a rotational position change amount of the crankshaft based on detection results of the third detection units of the two rotating electrical machines.   4. The vehicle control device according to claim 2, wherein the second determination unit determines whether or not the variable valve timing mechanism is in a swinging state when the internal combustion engine is cranking. 5.   The second determination means determines whether or not the variable valve timing mechanism is in a swaying state when the stop time from the previous stop of the internal combustion engine to the current cranking exceeds a predetermined threshold time. The vehicle control device according to claim 4, wherein the determination is made.   The control device according to claim 1, further comprising a fuel supply prohibiting unit that prohibits the supply of fuel to the internal combustion engine during a period in which the determination result by the first determination unit is invalidated by the invalidation unit. The vehicle control device according to claim 1.

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