JP2015117646A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an abnormality of an atmospheric pressure sensor without mounting a plurality of the atmospheric sensors to a vehicle.SOLUTION: Engine torque outputted by an internal combustion engine is estimated on the basis of an operation region of the internal combustion engine M1 which is mounted to a vehicle, and atmospheric pressure which is detected by an atmospheric sensor, the relative displacement of the internal combustion engine with respect to a vehicle body M4 is acquired by a displacement sensor, and the presence and absence of an abnormality of the atmospheric sensor is determined from a magnitude of a difference between the engine torque which is estimated on the basis of the displacement acquired by the displacement sensor, and actual engine torque.

Description

  The present invention relates to a control device that determines whether there is an abnormality in an atmospheric pressure sensor mounted on a vehicle.

  In the control of an internal combustion engine mounted on a vehicle, the amount of intake (fresh air) charged into a cylinder, and thus the amount of fuel injection, is corrected with reference to the atmospheric pressure measured via an atmospheric pressure sensor. .

  If the atmospheric pressure sensor does not function properly, the fuel injection amount cannot be optimized, and the amount of harmful substances contained in the exhaust gas may increase. Therefore, when an abnormality occurs in the atmospheric pressure sensor, it is necessary to quickly detect this.

  Conventionally, when the atmospheric pressure indicated by the output signal of the atmospheric pressure sensor has deviated from an unrealistic value that cannot be on the ground surface, specifically, a range of about 616 hPa to about 1064 hPa, It was determined that the failure of the atmospheric pressure sensor or the disconnection or short circuit of the signal line connected to the atmospheric pressure sensor occurred. However, in such a method, as long as the output signal of the atmospheric pressure sensor is within the range of about 616 hPa to about 1064 hPa, even if the output signal deviates from the actual atmospheric pressure, it is regarded as normal. End up. If a large error is mixed in the measured value of atmospheric pressure, an increase in the emission of harmful substances is inevitable.

  If a plurality of atmospheric pressure sensors are mounted on a vehicle and an atmospheric pressure measurement line is multiplexed (for example, refer to the following patent document), an effective fail-safe against abnormalities in the atmospheric pressure sensor is obtained. However, it is undeniable that the cost is disadvantageous.

JP 2006-226136 A

  An object of the present invention is to enable detection of an abnormality in an atmospheric pressure sensor without mounting a plurality of atmospheric pressure sensors on a vehicle.

  In the present invention, the actual engine torque output from the internal combustion engine is estimated based on the operating region of the internal combustion engine mounted on the vehicle and the atmospheric pressure detected via the atmospheric pressure sensor, and the relative displacement of the internal combustion engine relative to the vehicle body is estimated. Is obtained via a displacement sensor, and is estimated based on the difference between the engine torque estimated based on the displacement obtained via the displacement sensor and the actual engine torque, or based on the actual engine torque. A control device for determining the presence or absence of abnormality of the atmospheric pressure sensor is configured based on the difference between the relative displacement of the internal combustion engine with respect to the vehicle body and the displacement obtained through the displacement sensor.

  According to the present invention, it is possible to detect an abnormality in the atmospheric pressure sensor without mounting a plurality of atmospheric pressure sensors on the vehicle.

The figure which shows the structure of the internal combustion engine and control apparatus in one Embodiment of this invention. The front view which shows the support structure of the internal combustion engine using the engine mount apparatus in one Embodiment of this invention. The sectional side view of the engine mount device. The sectional side view which shows the modification of an engine mount apparatus. The side view which shows the pattern of the displacement of the internal combustion engine with respect to a vehicle body. The figure which illustrates the relationship between an engine torque and engine speed, and the relative displacement amount with respect to the vehicle body of an internal combustion engine.

  An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the outline | summary of the internal combustion engine M1 for vehicles in this embodiment is shown. The internal combustion engine M1 is a spark ignition type four-stroke gasoline engine and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  An external EGR (Exhaust Gas Recirculation) device 2 is attached to the internal combustion engine M1. The external EGR device 2 realizes a so-called high-pressure loop EGR. The EGR device 21 communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3, and the EGR passage 21. The EGR cooler 22 provided in the EGR passage and the EGR valve 23 that opens and closes the EGR passage 21 and controls the flow rate of the EGR gas flowing through the EGR passage 21 are used as elements. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, specifically to a surge tank 33.

  FIG. 2 shows an example of a support structure for mounting an internal combustion engine M1 and drive systems M2 and M3 mounted on a vehicle to a vehicle body M4 via an engine mount device M5.

  The support structure shown in FIG. 2 is of a so-called horizontal FF (Front-engine Front-drive) type. That is, the internal combustion engine M1 is disposed in front of the vehicle so that the crankshaft extends sideways so as to extend along the left-right direction of the vehicle. On the side of the internal combustion engine M1, a torque converter M2, a transmission case M3, and the like constituting the drive system are assembled, and these are integrated with the internal combustion engine M1. The left and right sides of the unit (one side of the internal combustion engine M1 and the other side of the transmission case M3) are attached to the subframe M41, which is a part of the vehicle body M4, via the engine mount device M5. A rear portion (torque converter M2) of the unit is connected to a front suspension member M42 which is a part of the vehicle body M4 via a torque rod M6. Both side portions of the unit are placed on the engine mount device M5 via the engine mount bracket M7.

  As shown in FIG. 3, the engine mount device M5 includes an attachment fitting M51 on the internal combustion engine M1 side that is fastened to the engine mount bracket M7, an attachment fitting M52 on the vehicle body M4 side that is fastened to the subframe M41, and these attachment fittings. The main components are a vibration isolating member M53 that is interposed between M51 and M52 and joins them, and a buffer liquid M54 sealed in a small chamber formed in the vibration isolating member M53.

  The anti-vibration member M53 is mainly composed of elastically deformable rubber or the like. The anti-vibration member M53 and the enclosed buffer liquid M54 prevent the vibration transmitted from the internal combustion engine M1 to the vehicle body M4, and the oscillation of the internal combustion engine M1 due to torque reaction force, input from the road surface, and the like. Operates the damping action to suppress.

  In addition, in the present embodiment, relative displacement of the internal combustion engine M1 with respect to the vehicle body M4 is placed inside an engine mount device M5 that mounts one side portion (side portion of the internal combustion engine M1) of the unit on the vehicle body M4. Implements a mechanism to detect

  Specifically, as shown in FIG. 3, the engine mount device M5 is fixed to the mounting magnet M51 on the internal combustion engine M1 side and fixed to the mounting body M52 on the vehicle body M4 side. A magnetic field detection element M56 is provided. The magnetic field detection element M56 is typically a Hall element that detects a magnetic field using the Hall effect, but other aspects such as a coil, a fluxgate magnetic field sensor, a Wiegand wire, and the like are used as the magnetic field detection element M56. It does not preclude adoption.

  When the internal combustion engine M1 is displaced relative to the vehicle body M4, the magnet M55 is displaced relative to the magnetic field detection element M56. According to the magnetic field detection element M56, the displacement amount and the direction of the displacement of the magnet M55 can be detected. As a result, it is possible to know the amount of displacement and the direction of displacement of the internal combustion engine M1 relative to the vehicle body M4. The magnetic field detection element M56 is connected to an ECU (Electronic Control Unit) 0 that controls operation of the internal combustion engine M1 and / or the drive systems M2 and M3.

  It should be noted that the displacement detection mechanism of the engine mount device M5 can be applied to an active engine mount. FIG. 4 shows a modified engine mount apparatus M5 that implements an active engine mount function. The engine mount device M5 according to the present modification includes a plurality of orifices M57 and M58 through which the enclosed buffer fluid flows, and valves M59 and M50 that can open and close the orifices M57 and M58. The other points are the same as those of the engine mount device M5 shown in FIG. That is, a permanent magnet M55 fixed to the mounting bracket M51 on the internal combustion engine M1 side and a magnetic field detection element M56 fixed to the mounting bracket M52 on the vehicle body M4 side are provided in the engine mount device M5. .

  The orifices M57 and M58 are arranged apart from each other in a direction orthogonal to the direction in which the crankshaft of the internal combustion engine M1 extends. When the internal combustion engine M1 is mounted on a vehicle by the horizontally placed FF method, the orifices are separated from each other in the front-rear direction.

  The valves M59 and M50 corresponding to the orifices M57 and M58 are, for example, solenoid valves that can be operated by inputting a control signal from the ECU 0. Through the operation of the valves M59 and M50, the orifices M57 and M58 can be opened and closed, or the openings of the orifices M57 and M58 can be expanded or reduced.

  FIG. 5 shows an example of relative displacement of the internal combustion engine M1 with respect to the vehicle body M4. As shown in FIG. 5A, the internal combustion engine M1 can swing back and forth with respect to the vehicle body M4. When the vehicle is accelerating or when the vehicle is traveling uphill, as shown in FIG. 5B, the internal combustion engine M1 is displaced relatively rearward so as to tilt backward with respect to the vehicle body M4. When the vehicle is decelerating or the vehicle is traveling downhill, as shown in FIG. 5C, the internal combustion engine M1 is displaced relatively forward so as to tilt forward with respect to the vehicle body M4. .

  When the air-fuel mixture is combusted in the combustion chamber of the cylinder 1, positive engine torque, that is, torque that accelerates rotation of the crankshaft acts on the crankshaft of the internal combustion engine M1. At this time, a force in the direction opposite to the rotation direction of the crankshaft acts on the main body of the internal combustion engine M1. That is, the main body of the internal combustion engine M1 is displaced rearward relative to the vehicle body M4. The amount of displacement increases as the positive engine torque acting on the crankshaft increases.

When the internal combustion engine M1 is displaced rearward relative to the vehicle body M4, the rear portion of the vibration isolating member M53 is deformed so as to be crushed, and the rear portion of the small chamber in which the buffer liquid M54 is sealed is compressed to have its volume. Shrinks. Thereby, the buffer liquid M54 flows downward in the orifice M58 at the rear. Further, the ECU 0 that has detected the rearward displacement of the internal combustion engine M1 with respect to the vehicle body M4, which may flow upward in the orifice M57 at the front, via the displacement detection mechanism, is at least a valve M50 attached to the orifice M58 at the rear. To close the orifice M58 or reduce its opening. Then, further deformation of the vibration isolating member M53 is prevented, and further rearward displacement of the internal combustion engine M1 is suppressed. At this time, the valve M59 attached to the orifice M57 at the front may be operated to close the orifice M57 or reduce the opening.

  In contrast, when the internal combustion engine M1 is displaced forward relative to the vehicle body M4, the front part of the vibration isolating member M53 is deformed so as to be crushed, and the front part of the small chamber in which the buffer liquid M54 is sealed is formed. Compressed to reduce its volume. Thereby, the buffer liquid M54 flows downward in the orifice M57 in the front. In addition, it may flow upward in the orifice M58 located at the rear.

  The ECU 0 that has detected the forward displacement of the internal combustion engine M1 with respect to the vehicle body M4 via the displacement detection mechanism operates at least the valve M59 attached to the orifice M57 at the front to close or open the orifice M57. Squeeze the degree. Then, further deformation of the vibration isolating member M53 is prevented, and further forward displacement of the internal combustion engine M1 is suppressed. At this time, the valve M50 attached to the rear orifice M58 may be operated to close the orifice M58 or reduce the opening.

  In the modification shown in FIG. 4, the valves M59 and M50 are attached to the front orifice M57 and the rear orifice M58, respectively, but the valves M59 and M50 are attached to only one of the orifices M57 and M58. May be.

  In the engine mount apparatus M5 shown in FIGS. 3 and 4, the magnet M55 is provided on the internal combustion engine M1 side and the magnetic field detection element M56 is provided on the vehicle body M4 side. The magnet M55 may be provided on the vehicle body M4 side, and the magnetic field detection element M56 may be provided on the internal combustion engine M1 side. In this case, the magnet M55 is fixed to the mounting member on the vehicle body M4 side, and the magnetic field detection element M56 is fixed to the mounting member on the internal combustion engine M1 side.

  The ECU 0 as the control device of the present embodiment is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle signal b output from an engine rotation sensor that detects the rotation angle and engine speed of the crankshaft, and depression of an accelerator pedal. The accelerator opening signal c output from a sensor that detects the amount or the opening of the throttle valve 32 as an accelerator opening (so-called required load), the intake air temperature and the intake pressure in the intake passage 3 (particularly, the surge tank 33). The intake air temperature / intake pressure signal d output from the temperature / pressure sensor to be detected, the coolant temperature signal e output from the water temperature sensor that detects the coolant temperature of the engine M1, and the large pressure output from the atmospheric pressure sensor that detects the atmospheric pressure. An atmospheric pressure signal f, an inclination angle detected from an inclination angle sensor (or an acceleration sensor) that detects the inclination of the road surface on which the vehicle is located (or an acceleration sensor) Or an acceleration) signal g, a cam angle signal h output from the cam angle sensor at a plurality of cam angles of the intake camshaft or exhaust camshaft, and a displacement signal output from the magnetic field detection element M56 constituting the displacement detection mechanism. m and the like are input.

  From the output interface, the ignition signal i for the igniter of the spark plug 12, the fuel injection signal j for the injector 11, the opening operation signal k for the throttle valve 32, and the opening operation signal l for the EGR valve 23. An opening operation signal p is output to the valve M59, and an opening operation signal q is output to the valve M50.

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates an operation parameter, and controls the operation of the internal combustion engine M1. The ECU 0 obtains various information a, b, c, d, e, f, g, h, m necessary for operation control of the internal combustion engine M1 through the input interface, knows the engine speed, and stores it in the cylinder 1. Estimate the amount of intake air to be filled. Then, operating parameters such as required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, required EGR rate (or EGR amount), and the like are determined. The ECU 0 applies various control signals i, j, k, l, p, q corresponding to the operation parameters via the output interface.

  Thus, the ECU 0 of the present embodiment performs a diagnosis for diagnosing whether or not the atmospheric pressure sensor is abnormal. In the diagnosis process, the ECU 0 refers to the relative displacement of the internal combustion engine M1 with respect to the vehicle body M4, which is detected via the displacement detection mechanism of the engine mount device M5.

  The magnitude of the actual engine torque output from the operating internal combustion engine M1 is the operating area of the internal combustion engine at that time [engine speed, intake pressure in the surge tank 33 (or required load, intake air amount filled in the cylinder 1) )] And atmospheric pressure.

  More specifically, the basic amount T of the actual engine torque and the charging efficiency Ec of the internal combustion engine M1 are detected by the intake pressure in the surge tank 33 (if an air flow meter is installed in the intake passage 3, the air flow meter detects the intake pressure). It can be obtained from the intake valve flow rate), the throttle valve 32 opening and the engine speed. In the memory of the ECU 0, map data defining the relationship among the intake pressure (or intake flow rate), the throttle valve 32 opening and the engine speed, the basic amount T of the actual engine torque, and the charging efficiency Ec is stored in advance. Yes. The ECU 0 knows the current basic amount T of the actual engine torque by searching the map using the current intake pressure (or intake flow rate), the throttle valve 32 opening degree, and the engine speed as keys.

Further, the ECU 0 corrects the basic amount T according to the following formula, and obtains a more accurate actual engine torque T ′ that takes into account the current atmospheric pressure.
T ′ = T × {(Vc / V) × (PA / P) + Ec} / Ec
Here, Vc is the combustion chamber volume when the piston is located at the top dead center in the cylinder 1, and V is the combustion when the piston is located at the bottom dead center in the cylinder 1 (including the cylinder bore). The indoor volume, PA is the atmospheric pressure detected by the atmospheric pressure sensor, and P is the standard atmospheric pressure (= 1013.25 hPa). Incidentally, the compression ratio e = (Vc + V) / Vc.

  On the other hand, as shown in FIG. 5, there is a correlation between the engine torque output from the internal combustion engine M1 and the relative displacement of the internal combustion engine M1 with respect to the vehicle body M4. Therefore, the magnitude of the engine torque currently output from the internal combustion engine M1 can be estimated from the relative displacement amount of the internal combustion engine M1 detected through the displacement detection mechanism. FIG. 6 illustrates the relationship between the engine torque and the engine speed and the relative displacement amount of the internal combustion engine M1 with respect to the vehicle body M4.

  Of course, the relative displacement of the internal combustion engine M1 with respect to the vehicle body M4 is affected by the inclination of the road surface on which the vehicle is located. In order to estimate the engine torque using the displacement detection mechanism, it is necessary to take into account the road gradient (the relative displacement amount of the internal combustion engine M1 with respect to the vehicle body M4). In the memory of the ECU 0, the relationship between the relative displacement of the internal combustion engine M1 with respect to the vehicle body M4, the engine speed and the road surface gradient, and the estimated amount T ″ of the engine torque output from the internal combustion engine M1 is defined in advance. Stores map data. The ECU 0 searches the map using the relative displacement amount of the internal combustion engine M1 detected through the displacement detection mechanism, the current engine speed and the road surface gradient detected through the inclination angle sensor (or acceleration sensor) as keys. To obtain an estimated amount T ″ of the current engine torque.

  Then, the ECU 0 determines whether there is an abnormality in the atmospheric pressure sensor through a comparison between the actual engine torque T ′ and the estimated engine torque T ″. If the atmospheric pressure value measured by the atmospheric pressure sensor does not include an error, the actual engine torque T ′ and the estimated engine torque T ″ should agree well. On the other hand, if the atmospheric pressure value measured by the atmospheric pressure sensor includes a large error, the atmospheric pressure sensor is broken, or the signal line connected to the atmospheric pressure sensor is broken or short-circuited, the actual engine The difference between the torque T ′ and the estimated engine torque T ″ should be large. The ECU 0 compares the difference (absolute value) between the actual engine torque T ′ and the estimated engine torque T ″ with a determination threshold, and determines that an abnormality has occurred in the atmospheric pressure sensor when the former exceeds the latter. .

  The determination threshold is preferably variable according to the current engine speed. This is because, under the condition where the engine torque (and the road surface gradient) is the same, the higher the engine speed, the greater the relative displacement amount of the internal combustion engine M1 with respect to the vehicle body M4 and the greater the variation in the displacement amount. . Therefore, for example, the determination threshold is set larger as the engine speed is higher.

  The ECU 0 that has determined that an abnormality has occurred in the atmospheric pressure sensor thereafter determines the fuel injection amount without using the atmospheric pressure value obtained through the atmospheric pressure sensor. For example, the operation control of the internal combustion engine M1 is performed by regarding the atmospheric pressure as a predetermined value (standard atmospheric pressure or the like) that does not depend on the output signal f of the atmospheric pressure sensor.

  Moreover, ECU0 which judged that abnormality has generate | occur | produced in the atmospheric pressure sensor outputs that to the driver | operator's audiovisual sense, and notifies a driver | operator. For example, a warning light installed in the cockpit is turned on, a warning is displayed on the display screen, a buzzer, an alarm sound, and other sounds are output.

  In the present embodiment, the actual engine torque T ′ output from the internal combustion engine M1 is estimated based on the operating region of the internal combustion engine M1 mounted on the vehicle and the atmospheric pressure detected via the atmospheric pressure sensor, and the internal combustion engine M1 The relative displacement with respect to the vehicle body M4 is obtained via displacement sensors M55 and M56, and the engine torque T ″ estimated based on the displacement obtained via the displacement sensors M55 and M56 and the actual engine torque T ′. The control device 0 that determines whether or not the atmospheric pressure sensor is abnormal is configured based on the difference between the above and the atmospheric pressure sensor.

  According to this embodiment, it is possible to detect an abnormality in the atmospheric pressure sensor without mounting a plurality of atmospheric pressure sensors on the vehicle and multiplexing the atmospheric pressure measurement line.

  The displacement sensors M55 and M56 (displacement detection mechanism in the engine mount device M5) are capable of directly detecting the relative displacement of the internal combustion engine M1 with respect to the vehicle body M4, in other words, the behavior of the internal combustion engine M1. It can be manufactured at low cost.

  The displacement sensors M55 and M56 are used for applications other than the diagnosis of the atmospheric pressure sensor, such as an active engine mounting system, measurement of fluctuations in output torque of the internal combustion engine M1, measurement of fluctuations in the center of gravity of the vehicle, measurement of road surface gradients, internal combustion. It can be used for estimation of the combustion state of the air-fuel mixture in the cylinder 1 of the engine M1 (detection of misfire or knocking). In particular, if the positive engine torque generated as a result of combustion of the air-fuel mixture in the combustion chamber of the cylinder 1 is not within the range of an assumption (amount commensurate with the valve opening time of the injector 11 commanded from the ECU 0), the cylinder 1 is normal. It can be seen that no combustion was performed (abnormal combustion such as misfire, knocking, pre-ignition occurred).

  The present invention is not limited to the embodiment described in detail above. In the above embodiment, whether there is an abnormality in the atmospheric pressure sensor is determined based on the difference between the engine torque T ″ estimated based on the displacement obtained through the displacement sensors M55 and M56 and the actual engine torque T ′. It was. On the other hand, due to the difference between the relative displacement of the internal combustion engine M1 with respect to the vehicle body M4 estimated based on the actual engine torque T ′ and the displacement obtained through the displacement sensors M55 and M56, the atmospheric pressure sensor The presence or absence of abnormality may be determined.

  In this case, in the memory of the control unit ECU0, map data that preliminarily defines the relationship between the actual engine torque T ′, the engine speed and the road gradient, and the estimated amount of displacement relative to the vehicle body M4 of the internal combustion engine M1. Is stored. The ECU 0 searches the map using the current actual engine torque T ′, the engine speed and the road gradient as keys, and obtains an estimated amount of relative displacement of the internal combustion engine M1 relative to the vehicle body M4. Then, a difference (absolute value) between the estimated amount of the relative displacement and the relative displacement amount of the internal combustion engine M1 with respect to the vehicle body M4 measured through the displacement sensors M55 and M56 is obtained and compared with a determination threshold value. If the former exceeds the latter, it is determined that an abnormality has occurred in the atmospheric pressure sensor. The determination threshold is preferably variable according to the current engine speed (for example, the determination threshold is set to be larger as the engine speed is higher).

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to a control device for an internal combustion engine mounted on a vehicle.

0 ... Control unit (ECU)
M1 ... Internal combustion engine M4 ... Car body M5 ... Engine mount device M55, M56 ... Displacement sensor (magnet, magnetic field detection element)

Claims (1)

Estimating the actual engine torque output by the internal combustion engine based on the operating region of the internal combustion engine mounted on the vehicle and the atmospheric pressure detected via the atmospheric pressure sensor,
Knowing the relative displacement of the internal combustion engine with respect to the vehicle body via the displacement sensor,
Relative displacement of the internal combustion engine with respect to the vehicle body estimated based on the difference between the engine torque estimated based on the displacement obtained through the displacement sensor and the actual engine torque, or estimated based on the actual engine torque A control device that determines whether or not the atmospheric pressure sensor is abnormal based on a difference between the displacement and the displacement obtained through the displacement sensor.

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