JP2009062825A - Abnormality detection device and abnormality detection method of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality detection device and an abnormality detection method of an internal combustion engine which can accurately detect abnormalities in a cylinder of an internal combustion engine of which the output shaft is mechanically coupled to a rotary shaft of a motor-driven generator. <P>SOLUTION: The crankshaft 156 of the engine 150 is connected to a carrier shaft 127 of a planetary gear 120 via a damper 157 which includes a torsion member. When the crankshaft 156 and the carrier shaft 127 perform relative revolution, the torsion member generates an elastic force used for controlling the relative revolution. A control unit 180 makes estimated calculation of engine torque by using rotation-angle acceleration of the crankshaft 156 which is calculated from the detected value of a crank-angle sensor, and corrects the engine torque obtained by estimated calculation by a correction term which consists of the elastic force of the damper 157 which is calculated based on the twist angle of the damper 157. Then the control unit 180 diagnoses the abnorlalities of the engine 150 based on the corrected estimated engine torque. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an abnormality detection device and an abnormality detection method for an internal combustion engine, and more particularly to an abnormality detection device and an abnormality detection method for an internal combustion engine applied to a power output device including a plurality of power sources including the internal combustion engine.

  Conventionally, as an abnormality detection device for an internal combustion engine that detects an abnormal cylinder in which explosion combustion is no longer performed due to clogging or failure of a fuel injection valve, for example, Japanese Patent Laid-Open No. 2-49955 (Patent Document 1) discloses an output of an internal combustion engine. An internal combustion engine that detects the rotational angular velocity of the crankshaft, which is the shaft, in synchronism with the combustion stroke of each cylinder, and detects cylinder abnormalities accompanied by misfiring based on the deviation between the detected rotational angular velocity and the angular velocity reference value An engine cylinder abnormality detection device is disclosed.

According to this, when the difference between the rotation speed of the focused cylinder and the rotation speed of the previous cylinder, which is the reference value, is larger than a predetermined value, the cylinder abnormality detection device for the internal combustion engine is used for determining the next rotation speed. The reference value is set to a value larger than the rotation speed by the predetermined value. Therefore, even if an abnormality has occurred in any of the cylinders, and an accidental misfire has occurred in a cylinder that has undergone an explosion process immediately before that cylinder, the cylinder in which the abnormal state is intermittently generated is correctly It can be determined as abnormal.
JP-A-2-49955 JP-A-6-257480

  However, when the cylinder abnormality detection device described in Japanese Patent Laid-Open No. 2-49955 (Patent Document 1) is applied to a mechanically distributed hybrid vehicle, the abnormality of the internal combustion engine cannot be accurately detected for the following reason. There is a problem.

  Some hybrid vehicles including an internal combustion engine and a motor generator as a power source have a configuration in which a crankshaft of the internal combustion engine, a rotation shaft of the motor generator, and a drive shaft are mechanically coupled via a planetary gear. In the planetary gear, when the number of rotations and torque of two of the three rotation shafts described above are determined (hereinafter collectively referred to as a rotation state), the rotation state of the remaining rotation shafts is determined. It has the property of being uniquely determined.

  In the hybrid vehicle having such a configuration, the power output from the internal combustion engine is divided into power mechanically transmitted to the drive shaft and power regenerated as electric power, and further using the regenerated electric power. By running the motor generator, the vehicle can travel while outputting desired power. Further, since the power of the motor generator can be output from the drive shaft, it is possible to travel using only the power output from the motor generator.

  That is, in the hybrid vehicle, the crankshaft of the internal combustion engine and the rotating shaft of the motor generator are coupled in a state where they can be rotated at different rotational speeds having a correlation. Therefore, the rotational state of the motor generator greatly influences the rotational angular velocity of the crankshaft of the internal combustion engine.

  However, in the conventional cylinder abnormality detection device that detects cylinder abnormality based on the rotational angular velocity of the crankshaft, a power output device that uses only the engine as a power source is applied, and such a motor generator can rotate the crankshaft. It does not take into account the effect on the condition. As a result, it becomes difficult for the internal combustion engine to estimate the torque actually generated according to the combustion state with high accuracy, and therefore, there is a problem that cylinder abnormality of the internal combustion engine cannot be detected accurately.

  Therefore, the present invention has been made to solve such a problem, and an object thereof is to accurately detect a cylinder abnormality of an internal combustion engine in which an output shaft is mechanically coupled to a rotating shaft of a motor generator. An abnormality detection device and an abnormality detection method for an internal combustion engine are provided.

  According to this invention, the abnormality detection device for an internal combustion engine detects an abnormality of the internal combustion engine in the power output device that outputs power to the drive shaft using the internal combustion engine and the motor generator as a power source. The power output device mechanically couples an input shaft that receives power from the internal combustion engine, a rotating shaft and a drive shaft of the motor generator, and mechanically distributes power from the internal combustion engine to the motor generator and the drive shaft. And a damper that is coupled between the output shaft and the input shaft of the internal combustion engine and transmits power while suppressing relative rotation between the output shaft and the input shaft of the internal combustion engine. . An abnormality detection device for an internal combustion engine includes a torque estimation unit that estimates and calculates an output torque of the internal combustion engine based on a rotational angular acceleration of the output shaft of the internal combustion engine, and a rotation angle of each of the output shaft and the input shaft of the internal combustion engine. The internal combustion engine such that the damper suppresses relative rotation between the output shaft and the input shaft of the internal combustion engine based on the first and second rotational angle detection means and the detected rotational angles of the output shaft and the input shaft of the internal combustion engine. Based on the corrected output torque of the internal combustion engine, and the torque correction means for correcting the output torque of the internal combustion engine estimated and calculated based on the calculated elastic force of the damper And an abnormality diagnosis means for diagnosing abnormality of the internal combustion engine.

  Further, according to the present invention, an abnormality detection method for an internal combustion engine detects an abnormality of the internal combustion engine in a power output device that outputs power to a drive shaft using the internal combustion engine and a motor generator as a power source. It is. The power output device mechanically couples an input shaft that receives power from the internal combustion engine, a rotating shaft and a drive shaft of the motor generator, and mechanically distributes power from the internal combustion engine to the motor generator and the drive shaft. And a damper that is coupled between the output shaft and the input shaft of the internal combustion engine and transmits power while suppressing relative rotation between the output shaft and the input shaft of the internal combustion engine. . In the internal combustion engine abnormality detection method, the first step of estimating and calculating the output torque of the internal combustion engine based on the rotational angular acceleration of the output shaft of the internal combustion engine, and the rotation angles of the output shaft and the input shaft of the internal combustion engine are detected. Based on the second step and the detected rotation angles of the output shaft and the input shaft of the internal combustion engine, the damper is applied to the output shaft of the internal combustion engine so as to suppress the relative rotation between the output shaft of the internal combustion engine and the input shaft. And a third step of correcting the output torque of the internal combustion engine estimated and calculated based on the calculated elastic force of the damper, and the internal combustion engine based on the corrected output torque of the internal combustion engine. And a fourth step of diagnosing the abnormality.

  According to the abnormality detection device and abnormality detection method for an internal combustion engine described above, even if the rotation state of the output shaft of the internal combustion engine varies due to the influence of the rotation state of the motor generator, the motor generator As an elastic force generated by the damper, this influence can be excluded from the rotation state of the output shaft of the internal combustion engine. As a result, it is possible to accurately estimate the torque generated by the internal combustion engine in accordance with the combustion state, so that an abnormality of the internal combustion engine can be accurately detected.

  Preferably, the damper includes an elastic member that is compressed when the output shaft and the input shaft of the internal combustion engine rotate relative to each other, and applies an elastic force to both the shafts. The torque correction means acquires a difference between the rotation angle of the output shaft and the input shaft of the internal combustion engine detected by the first and second rotation angle detection means as a twist angle between the output shaft and the input shaft of the internal combustion engine. A twist angle acquisition means; and an elastic force calculation means for calculating the elastic force of the damper by multiplying the acquired twist angle by an elastic constant of the elastic member.

  Preferably, the damper includes an elastic member that is compressed when the output shaft and the input shaft of the internal combustion engine rotate relative to each other, and applies an elastic force to both the shafts. The third step is a first sub-step for obtaining a difference between the rotation angle of the output shaft and the input shaft of the internal combustion engine detected in the second step as a twist angle between the output shaft and the input shaft of the internal combustion engine. And a second sub-step of calculating the elastic force of the damper by multiplying the obtained twist angle by the elastic constant of the elastic member.

  According to the abnormality detection device and abnormality detection method for an internal combustion engine, it is possible to accurately estimate the influence of the rotational state of the motor generator as the elastic force generated in the elastic member included in the damper. As a result, the torque generated by the internal combustion engine according to the combustion state can be estimated with high accuracy.

  More preferably, the abnormality detection device for the internal combustion engine receives a rotation angle of the output shaft of the internal combustion engine from the first rotation angle detection means and a signal processing means that receives the rotation angle of the input shaft from the second rotation angle detection means. Is further provided. The signal processing means generates and outputs a first pulse signal having a period of rotation of a predetermined first unit angle as one cycle based on the rotation angle of the output shaft of the internal combustion engine, and from the first unit angle. And generating and outputting a second pulse signal having a period of rotation of the second larger unit angle as one cycle, and generating and outputting the first pulse signal based on the rotation angle of the input shaft, Generate and output a pulse signal. The torsion angle acquisition means includes a relative torsion angle calculation means for calculating a relative angle of the torsion angle in one cycle based on the first pulse signal for the output shaft and the input shaft of the internal combustion engine, and the output torque of the internal combustion engine is substantially equal. And a twist angle reference point detecting means for detecting a reference point of the twist angle based on the second pulse signal for the output shaft and the input shaft of the internal combustion engine when the engine is in a zero operating state, and a reference of the detected twist angle Based on the point and the second pulse signal for the output shaft and the input shaft of the internal combustion engine, absolute twist angle calculating means for calculating the absolute angle of the twist angle, and adding the relative angle and absolute angle of the calculated twist angle And a twist angle calculating means for calculating the twist angle.

  More preferably, in the second step, based on the detected rotation angle of the output shaft of the internal combustion engine, a first pulse signal having a period of rotation of a predetermined first unit angle as one cycle is generated and output. And generating and outputting a second pulse signal having a period of rotation of the second unit angle larger than the first unit angle as one cycle, and the detected rotation angle of the input shaft, Generating and outputting a pulse signal, and generating and outputting a second pulse signal. The first sub-step is based on the first pulse signal for the output shaft and the input shaft of the internal combustion engine, and on the basis of the first pulse signal for the output shaft and the input shaft of the internal combustion engine. Based on the step of calculating the angle and the second pulse signal for the output shaft and the input shaft of the internal combustion engine when the output torque of the internal combustion engine is substantially zero, the twist angle reference point is detected. A step of calculating an absolute angle of the twist angle based on the step, a reference point of the detected twist angle, and a second pulse signal for the output shaft and the input shaft of the internal combustion engine, and a relative angle of the calculated twist angle And calculating a relative twist angle between the output shaft and the input shaft of the internal combustion engine including a twist angle calculation means for calculating a twist angle by adding the absolute angle and the absolute angle. .

  According to the abnormality detection device and abnormality detection method for an internal combustion engine described above, the rotation angle of the output shaft and the rotation angle of the input shaft of the internal combustion engine are detected by the rotation angle detection means having the same angular resolution, and the detection is performed. By adopting a configuration in which the value is processed by the common signal processing means, it is possible to eliminate a communication delay that occurs when a signal processing means is provided for each rotation angle detection means. As a result, the twist angle can be calculated with high accuracy, so that the influence of the rotation state of the input shaft on the output shaft of the internal combustion engine can be estimated easily and accurately.

  Preferably, the power split mechanism includes at least three gear elements, and the gear elements include planetary gears respectively connected to the rotation shaft, the drive shaft, and the input shaft of the motor generator. The second rotation angle detection means is provided in an oil pump having a drive shaft connected to the input shaft and driven by the torque of the input shaft to supply lubricating oil to the planetary gear.

  More preferably, the second rotation angle detection means estimates and calculates the rotation angle of the input shaft based on the rotation state of the oil pump.

  Preferably, the power split mechanism includes at least three gear elements, and the gear elements include planetary gears respectively connected to the rotation shaft, the drive shaft, and the input shaft of the motor generator. In the second step, the rotation angle of the input shaft is estimated and calculated based on the rotation state of an oil pump that is connected to the input shaft and is driven by the torque of the input shaft to supply lubricating oil to the planetary gear.

  According to the abnormality detection device and abnormality detection method for an internal combustion engine, the second rotation angle detection is performed by detecting the rotation angle of the input shaft based on the rotation state of the oil pump arranged coaxially with the input shaft. The degree of freedom of arrangement of means can be increased. As a result, an increase in size of the power output device due to the arrangement of the means can be prevented.

  According to this invention, it is possible to estimate with high accuracy the torque generated by the internal combustion engine whose output shaft is mechanically coupled to the rotating shaft of the motor generator according to the combustion state. As a result, the cylinder abnormality of the internal combustion engine can be accurately detected based on the estimated torque.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

(Configuration of hybrid vehicle power output device)
FIG. 1 is a schematic block diagram of a power output apparatus for a hybrid vehicle to which an abnormality detection apparatus for an internal combustion engine according to an embodiment of the present invention is applied.

  1, power output device 100 includes a power transmission gear 111, a drive shaft 112, a differential gear 114, motor generators MG1 and MG2, a planetary gear 120, a power takeout gear 128, a chain belt 129, and the like. , An engine (internal combustion engine) 150, resolvers 139 and 149, a damper 157, a crank angle sensor 159, a rotation speed sensor 169, and a control device 180.

  Crankshaft 156 of engine 150 is connected to planetary gear 120 and motor generators MG1, MG2 via damper 157. The damper 157 suppresses the amplitude of the torsional vibration of the crankshaft 156 of the engine 150 and connects the crankshaft 156 to the planetary gear 120.

  The power take-off gear 128 is connected to the power transmission gear 111 via the chain belt 129. The power take-out gear 128 receives power from a ring gear (not shown) of the planetary gear 120 and transmits the received power to the power transmission gear 111 via the chain belt 129. The power transmission gear 111 transmits power to the drive wheels via the drive shaft 112 and the differential gear 114.

  FIG. 2 is an enlarged view of planetary gear 120 shown in FIG. 1, engine 150 and motor generators MG1, MG2 coupled thereto.

  Referring to FIG. 2, planetary gear 120 is coupled to a sun gear 121 coupled to a hollow sun gear shaft 125 passing through the center of an input shaft (carrier shaft) 127, and to a ring gear shaft 126 coaxial with input shaft 127. Are connected between the ring gear 122, the sun gear 121, and the ring gear 122, and are connected to a plurality of planetary pinion gears 123 that revolve while rotating on the outer periphery of the sun gear 121, and the ends of the input shaft 127. It is comprised from the planetary carrier 124 which supports a shaft.

  In this planetary gear 120, the sun gear shaft 125, the ring gear shaft 126, and the input shaft 127, which are coupled to the sun gear 121, the ring gear 122, and the planetary carrier 124, respectively, serve as power input / output shafts. When the input / output power is determined, the power input / output to / from the remaining one axis is determined based on the determined power input / output to the two axes. Input shaft 127 constitutes an “input shaft” that receives power from engine 150.

  The sun gear shaft 125 and the ring gear shaft 126 are provided with resolvers 139 and 149 for detecting the respective rotation angles θs and θr.

  A power takeout gear 128 for taking out power is coupled to the ring gear 122. The power take-out gear 128 is connected to the power transmission gear 111 by a chain belt 129, and power is transmitted between the power take-out gear 128 and the power transmission gear 111.

  Motor generator MG1 is configured as a synchronous motor generator, and includes a rotor 132 having a plurality of permanent magnets 135 on an outer peripheral surface, and a stator 133 around which a three-phase coil 134 that forms a rotating magnetic field is wound.

  Rotor 132 is coupled to sun gear shaft 125 coupled to sun gear 121 of planetary gear 120. The stator 133 is formed by laminating thin plates of non-oriented electrical steel plates, and is fixed to the case 119. The motor generator MG1 operates as an electric motor that rotates the rotor 132 by interaction with the rotation of the rotor 132 by the interaction between the magnetic field generated by the permanent magnet 135 and the magnetic field formed by the three-phase coil 134. It operates as a generator that generates electromotive force at both ends of the three-phase coil 134 due to the interaction between the magnetic field generated by the rotation and the rotation of the rotor 132.

  Motor generator MG2 includes a rotor 142 having a plurality of permanent magnets 145 on the outer peripheral surface, and a stator 143 wound with a three-phase coil 144 that forms a rotating magnetic field. The rotor 142 is coupled to a ring gear shaft 126 coupled to the ring gear 122 of the planetary gear 120, and the stator 143 is fixed to the case 119. The motor generator MG2 also operates as an electric motor or a generator, similarly to the motor generator MG1.

  The engine 150 is a direct injection gasoline engine in which fuel (for example, gasoline fuel) is directly injected into a cylinder. The engine 150 is not limited to this, and may be a port injection type gasoline engine. The crankshaft 156 is provided with a crank angle sensor 159 for detecting the engine rotation speed. As the crank angle sensor 159, the same magnetic pickup sensor as is normally used in a vehicle using only an internal combustion engine as a drive source is used.

  Further, the input shaft 127 is provided with a rotation speed sensor 169 for detecting the rotation angle of the input shaft 127. The rotation speed sensor 169 is composed of the same magnetic pickup sensor as the crank angle sensor 159 and has an angular resolution equivalent to that of the crank angle sensor 159.

  FIG. 3 is a schematic configuration diagram of the crank angle sensor 159 and the rotation speed sensor 169. Since both the sensors have the same configuration, the crank angle sensor 159 will be described as a representative.

  Referring to FIG. 3, a crank rotor 200 that is rotated in the direction of the arrow is attached to crankshaft 156. On the outer periphery of the crank rotor 200, for detecting the crank angle, for example, a missing tooth portion continuously missing two teeth out of 36 teeth formed at an equal angle for every 10 ° CA (Crank Angle). 204 is formed, and a tooth portion 202 having 34 (= 36-2) teeth is formed.

  The crank angle sensor 159 faces each tooth and detects the rotation angle of the crankshaft 156 by these teeth. The crank angle signal NE output from the crank angle sensor 159 is a pulse signal with a period of rotation of a predetermined crank angle (for example, 10 ° CA) as one cycle when the rotational position of the crankshaft 156 is not a predetermined specific position. Thus, when the crankshaft 156 comes to a specific position, it becomes a missing tooth signal with a period during which the crankshaft 156 rotates 30 ° as one cycle. The missing tooth signal is generated every time the crankshaft 156 makes one rotation (every 360 ° CA).

  When control device 180 (FIG. 1) receives crank angle signal NE from crank angle sensor 159, control device 180 starts detecting a missing tooth signal in crank angle signal NE. Then, when it is first detected that the crank angle signal NE is a missing tooth signal, the crank angle signal NE is divided thereafter, and the period during which the crankshaft 156 rotates 30 ° is defined as one cycle (ie, the crank angle signal NE). A 30 ° CA signal NE2 as a pulse signal is generated every time the shaft 156 rotates 30 ° (every 30 ° CA).

  Further, the control device 180 outputs a cam angle sensor (not shown) according to the rotation of the cam shaft of the engine 150 during a predetermined period of the 30 ° CA signal NE2 after detecting the missing tooth signal. When the rising edge of the cylinder discrimination signal is determined, the reference position signal TDC is generated at the end timing of the determination period. Therefore, the reference position signal TDC rises when the rotational position of the crankshaft 156 reaches a reference position advanced by a predetermined period from the specific position where the missing tooth signal is generated. The control device 180 controls the engine 150 that has performed cylinder discrimination based on various signals including the 30 ° CA signal NE2, the cylinder discrimination signal, and the reference position signal TDC.

  Furthermore, in the power output apparatus 100 according to the present embodiment, the input shaft 127 is provided with a rotational speed sensor 169 having an angular resolution equivalent to that of the crank angle sensor 159.

  That is, when the rotational position of the input shaft 127 is not a preset specific position, the rotational speed sensor 169 generates a pulse signal with a period of rotation of a predetermined angle (for example, 10 ° CA) as one cycle, and the input shaft 127 is When a specific position is reached, a rotation pulse signal NI that is a missing tooth signal with a period during which the input shaft 127 rotates 30 ° as one cycle is output.

  When control device 180 (FIG. 1) receives rotation pulse signal NI from rotation speed sensor 169, control device 180 starts an operation of detecting a missing tooth signal in rotation pulse signal NI. Then, when it is first detected that the rotation pulse signal NI is a missing tooth signal, the rotation pulse signal NI is divided thereafter, and the period during which the input shaft 127 rotates 30 ° is defined as one cycle (ie, input A 30 ° CA signal NI2 as a pulse signal is generated every time the shaft 127 rotates 30 ° (every 30 ° CA).

  Based on the 30 ° CA signal NE2 for the crankshaft 156 and the 30 ° CA signal NI2 for the input shaft 127 described above, the control device 180 determines the relative relationship between the crankshaft 156 and the input shaft 127 by a method described later. A twist angle of the damper 157 that is an angle difference is calculated.

  In this manner, the input shaft 127 is provided with the rotation speed sensor 169 having an angle resolution equivalent to that of the crank angle sensor 159, and the signal output from each sensor is received by the common control device 180. Accordingly, for example, a communication delay can be eliminated as compared with a configuration in which a resolver is provided on the input shaft 127 and the sensor output is communicated between the signal processing circuit built in the resolver and the control device 180. Thereby, since the twist angle of the damper 157 can be calculated with high accuracy, the estimation accuracy of the engine torque can be improved. As a result, it is possible to accurately detect an abnormality in the engine 150.

  Referring to FIG. 1 again, control device 180 has a rotation angle θs of sun gear shaft 125 from resolver 139, a rotation angle θr of ring gear shaft 126 from resolver 149, a crank angle signal NE from crank angle sensor 159, and a rotation speed. Rotation pulse signal NI of input shaft 127 from sensor 169, accelerator pedal position AP from accelerator pedal position sensor 164a, brake pedal position BP from brake pedal position sensor 165a, shift position SP from shift position sensor 185, motor generator MG1 Motor current MCRT1 from a current sensor (not shown) attached to the motor generator MG2 and a motor current MCRT2 from a current sensor (not shown) attached to the motor generator MG2.

  Controller 180 drives motor generators MG1 and MG2 based on these various input signals by controlling the currents flowing through three-phase coils 134 and 144 of motor generators MG1 and MG2.

  Control device 180 constitutes an “abnormality detection device for an internal combustion engine” that detects an abnormality in engine 150. Based on the rotation angle of crankshaft 156 and the rotation angle of input shaft 127, control device 180 estimates and calculates engine torque by a method described later, and detects an abnormality in engine 150 based on the estimated and calculated engine torque. .

(Configuration of damper 157)
The crankshaft 156 of the engine 150 is connected to the input shaft 127 of the planetary gear 120 via a damper 157. 4 is a partially cutaway plan view of the damper 157 shown in FIG. The damper 157 constitutes a torque fluctuation absorbing mechanism that suppresses torsional vibration from the crankshaft 156 as described below.

  2 and 4, the damper 157 is connected to the crankshaft 156 of the engine 150 and is driven to rotate together with the crankshaft 156, and the damper 157 is disposed coaxially with the driving wheel 160 so as to be relatively rotatable. A driven wheel 164 provided and coupled to the input shaft 127, and an intermediate member 162 disposed so as to be relatively rotatable with respect to each of the driving wheel 160 and the driven wheel 164 within a predetermined angle range. including.

  Further, the damper 157 is disposed in the window of the driven wheel 164 and the intermediate member 162 and elastically suppresses the fluctuation torque between the driving wheel 160 and the driven wheel 164 by elastically contracting in the circumferential direction. A torsion member 161 that is a member, and a torque limiter 158 that interrupts transmission of power from the driving wheel 160 to the driven wheel 164 when the fluctuation torque between the driving wheel 160 and the driven wheel 164 reaches a predetermined value; including.

  The operation of the damper 157 configured as described above will be described. When only the engine 150 is driven, the driving wheel 160 rotates as the engine 150 is driven. At this time, when the fluctuation torque due to the inertia of the engine 150 is smaller than a predetermined value, the rotational torque is transmitted to the intermediate member 162 via the torque limiter 158, and the intermediate member 162 rotates. The rotational torque of the intermediate member 162 is transmitted to the driven wheel 164 via the torsion member 161, and the driven wheel 164 rotates while the torsion member 161 is elastically contracted according to the fluctuation torque. In this way, the drive of the engine 150 is transmitted to the input shaft 127 via the damper 157.

  When the driving torque of the engine 150 increases from the above state and the fluctuation torque between the driving side wheel 160 and the driven side wheel 164 reaches a predetermined value, the friction material in the torque limiter 158 starts to slide, and the intermediate member 162 and Fluctuating torque exceeding a predetermined value is not transmitted to the driven wheel 164.

  As described above, the damper 157 is controlled by the plurality of power sources (the engine 150 and the motor generators MG1, MG2) by the torsion member 161 and the torque limiter 158 suppressing the relative rotation between the driving wheel 160 and the driven wheel 164. Transmission is performed while suppressing the generated fluctuation torque.

  On the other hand, the crankshaft 156 and the input shaft 127 are connected via the damper 157, so that in the power output apparatus 100, the conventional cylinder abnormality applied to the power output apparatus using only the engine as a power source. When the detection device is used, there is a problem that an abnormality of the engine 150 cannot be detected accurately.

  That is, the conventional cylinder abnormality detection device is configured to detect an abnormality of the engine based on the rotational angular velocity of the crankshaft as described above. In the power output device using only the engine as the power source, the actual engine torque is multiplied by the rotational angular acceleration of the crankshaft calculated from the detection value of the crank angle sensor arranged on the crankshaft and the inertia of the engine. This is because the estimation calculation can be easily performed.

  However, in the hybrid vehicle power output apparatus 100 as shown in FIG. 1, the rotation state of the crankshaft 156 is greatly influenced by the rotation state of the motor generators MG <b> 1 and MG <b> 2 via the damper 157. In other words, the rotational state of motor generators MG1 and MG2 acts on crankshaft 156 as the elastic force of damper 157 in the rotational direction. For this reason, there is a difference between the estimated engine torque obtained by multiplying the rotational angular acceleration of the crankshaft 156 and the inertia of the engine and the actual engine torque. Therefore, it is difficult to ensure the abnormality detection accuracy in the configuration in which the abnormality of the engine is detected based on the estimated engine torque.

  Therefore, in the power output apparatus 100 according to the present embodiment, the engine torque estimation means estimates the engine torque using the rotational angular acceleration of the crankshaft 156 calculated based on the crank angle signal NE from the crank angle sensor 159. In addition to the calculation, the estimated engine torque is corrected by a correction term composed of the elastic force of the damper 157 calculated based on the twist angle of the damper 157.

  With such a configuration, even if the rotation state of the crankshaft 156 changes due to the change in the rotation state of the motor generators MG1 and MG2, the influence from the motor generators MG1 and MG2 is affected. By quantifying the elastic force generated in the damper 157, this can be excluded from the rotation state of the crankshaft 156. As a result, it is possible to detect only fluctuations in the rotational state of the engine 150 caused by the true combustion state, so that it is possible to accurately detect an abnormality in the engine 150.

  The engine torque estimation method according to the present embodiment will be described in detail below. The estimation of the engine torque according to the present embodiment is performed by calculating the twist angle of the damper 157 and estimating and calculating the engine torque using the correction term calculated based on the damper twist angle.

[1] Calculation of damper twist angle As described below, the twist angle of the damper 157 is the absolute angle of the twist angle (hereinafter also referred to as the absolute twist angle) and the relative angle of the twist angle (hereinafter also referred to as the relative twist angle). Is calculated by adding each of the calculation results.

  Here, the absolute angle of the torsion angle (absolute torsion angle) is based on the torsion angle when the engine 150 is performing the no-load operation in which the engine torque can be regarded as substantially zero as the reference point. Is an angle. Therefore, the absolute twist angle is a fluctuation amount that varies depending on the engine torque. On the other hand, the relative angle of the twist angle (relative twist angle) is a fluctuation amount that varies according to the combustion state of the engine 150 around the absolute twist angle. For example, the relative twist angle is about 1/10 of the absolute twist angle. Then, by adding the relative twist angle to the absolute twist angle, an accurate twist angle in which both the engine torque and the combustion state are considered can be obtained.

(Calculation of relative twist angle)
First, a method for calculating the relative twist angle of the damper 157 will be described with reference to FIGS. 5 and 6.

  FIG. 5I is a timing chart of 30 ° CA signals NE2 and NI2 for the crankshaft 156 and the input shaft 127. FIG. 5 (II) shows the engine speed calculated based on the 30 ° CA signal NE2 for the crankshaft 156.

  As described above, the 30 ° CA signal NE2 is generated based on the crank angle signal NE from the crank angle sensor 159 (FIG. 1), and is a pulse signal with one period of the period during which the crankshaft 156 rotates 30 °. It is. The 30 ° CA signal NI2 is a pulse signal that is generated based on the rotation pulse signal NI from the rotation speed sensor 169 (FIG. 1), and that the period during which the input shaft 127 rotates 30 ° is one cycle.

  The relative twist angle of the damper 157 is calculated based on the 30 ° CA signals NE2 and NI2 by calculating the angle difference between the crankshaft 156 and the input shaft 127 in one cycle (the period during which the crankshaft 156 rotates by 30 °). Is required.

  Specifically, referring to FIG. 5I, a time difference ΔT1 between 30 ° CA signal NE2 and 30 ° CA signal NI2 is calculated for each period. Further, a time T30 required for the crankshaft 156 to rotate 30 ° is calculated for each cycle. Then, the calculated time difference ΔT is converted into an angle difference Δθr between the crankshaft 156 and the input shaft 127 by the equation (1) using the calculated time T30.

Δθr / 30 [° CA] = ΔT1 / T30 (1)
The converted angle difference Δθr has a waveform as indicated by a line LN1 in FIG. This angle difference Δθr is the relative twist angle of the damper 157. The line LN2 in the figure is obtained by experimentally determining the angular difference between the crankshaft 156 and the input shaft 127.

  FIG. 6 is a flowchart for explaining the operation of calculating the relative twist angle of the damper 157 according to the present embodiment. The processing of each step shown in FIG. 6 is performed by control device 180 every cycle (corresponding to a period during which crankshaft 156 rotates by 30 °).

  Referring to FIG. 6, when a series of operations is started, control device 180 acquires crank angle signal NE from crank angle sensor 159 (FIG. 1) (step S01). Further, a rotation pulse signal NI for the input shaft 127 is acquired from the rotation speed sensor (FIG. 1) (step S02). Then, based on the obtained crank angle signal NE and rotation pulse signal NI, control device 180 generates 30 ° CA signal NE2 and 30 ° CA signal NI2 by the method described above (step S03).

  Next, control device 180 calculates time difference ΔT1 between 30 ° CA signal NE2 and 30 ° CA signal NI2 (step S04). Further, control device 180 calculates time T30 required for crankshaft 156 to rotate 30 ° based on 30 ° CA signal NE2 (step S05).

  Finally, control device 180 calculates relative twist angle Δθr, which is the angle difference between crankshaft 156 and input shaft 127, based on time difference ΔT1 and time T30 calculated in steps S04 and S05, respectively (step S06).

(Calculation of absolute twist angle)
Next, a method for calculating the absolute twist angle of the damper 157 will be described with reference to FIGS. 7 and 8.

  FIG. 7 is a timing chart of the engine speed calculated based on the 360 ° CA signals NE3 and NI3 for the crankshaft 156 and the input shaft 127 and the 30 ° CA signal NE2 for the crankshaft 156.

  Here, the 360 ° CA signal NE3 is generated by the control device 180 based on a missing tooth signal that is generated every time the crankshaft 156 rotates (every 360 ° CA) in the crank angle signal NE from the crank angle sensor 159. Signal. Similarly, the 360 ° CA signal NI3 is a signal generated by the control device 180 based on a missing tooth signal generated every time the input shaft 127 makes one rotation in the rotation pulse signal NI from the rotation speed sensor 169.

  First, the absolute twist angle of the damper 157 detects the origin of the twist angle based on these 360 ° CA signals NE3 and NI3. The origin of the twist angle is detected by calculating the twist angle when the engine 150 is performing no-load operation.

  Specifically, referring to (1) in FIG. 7, the twist angle during no-load operation is set to one period (a period during which the crankshaft 156 rotates 360 ° based on 360 ° CA signals NE3 and NI3). ) To calculate the angle difference Δθ0 between the crankshaft 156 and the input shaft 127.

  More specifically, the time difference ΔT0 between the 360 ° CA signal NE3 and the 360 ° CA signal NI3 is calculated for each cycle. Further, a time T30 required for the crankshaft 156 to rotate 30 ° is calculated for each cycle. Then, the calculated time difference ΔT0 is converted into an angle difference Δθ0 between the crankshaft 156 and the input shaft 127 by the equation (2) using the calculated time T30.

Δθ0 / 30 [° CA] = ΔT0 / T30 (2)
The angle difference Δθ0 at this time is stored in the storage area inside the control device 180 (FIG. 1) as the origin of the twist angle, and is read from the storage area and used when calculating the absolute twist angle. The origin Δθ0 is calculated every time the engine 150 enters a no-load operation state. Then, the origin in the storage area is updated to the calculated origin Δθ0.

  Next, the twist angle when the engine 150 is performing load operation is calculated by the same method. Specifically, referring to (2) of FIG. 7, based on the 360 ° CA signals NE3 and NI3, the crankshaft 156 and the input shaft 127 in one cycle (the period during which the crankshaft 156 rotates 360 °) is obtained. Is calculated by calculating the angle difference ΔθL between

  More specifically, the time difference ΔTL between the 360 ° CA signal NE3 and the 360 ° CA signal NI3 is calculated for each cycle. Further, a time T30 required for the crankshaft 156 to rotate 30 ° is calculated for each cycle. Then, the calculated time difference ΔTL is converted into an angle difference ΔθL between the crankshaft 156 and the input shaft 127 by Equation (3) using the calculated time T30.

ΔθL / 30 [° CA] = ΔTL / T30 (3)
Finally, by calculating the difference between the angle difference ΔθL calculated by the above equation (3) and the angle difference Δθ0 calculated by the above equation (2), the absolute angle Δθa of the twist angle can be obtained.

ΔθL−Δθ0 = Δθa (4)
FIG. 8 is a flowchart for explaining the operation of calculating the absolute twist angle of the damper 157 according to the present embodiment. Note that the processing of each step shown in FIG. 8 is performed by control device 180 at predetermined intervals (corresponding to a period during which crankshaft 156 rotates 360 °).

  Referring to FIG. 8, when a series of operations is started, control device 180 acquires crank angle signal NE from crank angle sensor 159 (FIG. 1) (step S11). Further, a rotation pulse signal NI for the input shaft 127 is acquired from the rotation speed sensor (FIG. 1) (step S12). Then, control device 180 generates 360 ° CA signal NE3 and 360 ° CA signal NI3 by the method described above based on the obtained crank angle signal NE and rotation pulse signal NI (step S13).

  Next, control device 180 determines whether engine 150 is in a no-load operation state (step S14). When engine 150 is in the no-load operation state (YES in step S14), control device 180 calculates a twist angle origin Δθ0 and updates the origin in the storage area.

  Specifically, control device 180 calculates time difference ΔT0 between 360 ° CA signal NE3 and 360 ° CA signal NI3 (step S19). Further, control device 180 calculates time T30 required for crankshaft 156 to rotate 30 ° based on 30 ° CA signal NE2 (step S20).

  Then, control device 180 calculates angle difference Δθ0 between crankshaft 156 and input shaft 127 by substituting time difference ΔT0 and time T30 calculated in steps S19 and S20, respectively, into the above equation (2) (step S21). . When control device 180 updates the origin stored in the storage area to calculated angle difference Δθ0, control proceeds to step S18.

  In contrast, when engine 150 is not in the no-load operation state (NO in step S14), control device 180 calculates twist angle ΔθL, and based on the calculated twist angle ΔθL and origin Δθ0. Thus, the absolute twist angle Δθa is calculated.

  Specifically, control device 180 calculates time difference ΔTL between 360 ° CA signal NE3 and 360 ° CA signal NI3 (step S15). Further, control device 180 calculates time T30 required for crankshaft 156 to rotate 30 ° based on 30 ° CA signal NE2 (step S16).

  Then, control device 180 calculates angle difference ΔθL between crankshaft 156 and input shaft 127 by substituting time difference ΔTL and time T30 calculated in steps S15 and S16, respectively, into the above equation (3) (step S17). .

  Finally, when reading the origin Δθ0 from the storage area, the control device 180 calculates the absolute twist angle Δθa by calculating the difference between the angle difference ΔθL calculated in step S17 and the origin Δθ0 (step S18).

  When the relative twist angle Δθr and the absolute twist angle Δθa are calculated according to the flowcharts of FIGS. 6 and 8, the control device 180 adds the angles using Equation (5), whereby the twist angle of the damper 157 is calculated. Δθd is calculated.

Δθr + Δθa = Δθd (5)
[2] Engine Torque Estimation Calculation Means Next, means for calculating a correction term using the damper twist angle Δθd obtained in [1] above and correcting the estimated engine torque with the calculated correction term will be described.

  The engine torque Te can usually be estimated by multiplying the rotational angular acceleration dωe / dt of the crankshaft 156 and the inertia Ie of the engine.

Te = Ie · dωe / dt (6)
Here, as described above, in power output apparatus 100 according to the present embodiment, crankshaft 156 is coupled to input shaft 127 via damper 157, so that the influence of the rotation state of motor generators MG1 and MG2 is affected. Receive. For this reason, there is a difference between the estimated torque obtained by the equation (6) and the actual torque. In particular, when the torque fluctuation of the engine 150 is large and the torque limiter 158 is activated, this deviation becomes large.

  Therefore, in the present embodiment, as shown in the following equation, the engine torque is corrected by adding the elastic force generated by the damper 157 as a correction term to the estimated engine torque Te calculated by the equation (6). To do.

TE = Te + Tf + Kdamp · θdi (7)
Here, Tf is the friction torque, and Kdamp is the spring constant of the torsion member 161 of the damper 157.

  Note that the friction torque Tf in the second term on the right side of Equation (7) is a torque due to mechanical friction of each fitting portion such as friction between the piston and the inner wall of the cylinder. Specifically, a two-dimensional map that prescribes the relationship between the rotational speed of the engine 150, the coolant temperature, and the intake pressure is created in advance by experiments or the like, and the engine 150 at that time is operated by referring to the map. A friction torque Tf corresponding to the state is obtained.

  As described above, according to the engine torque estimation calculation means according to the present embodiment, the influence of motor generators MG1 and MG2 can be eliminated from the rotation state of engine 150, and therefore it occurs according to the combustion state. The output torque of the engine 150 can be estimated with high accuracy. As a result, it is possible to accurately detect an abnormality in the engine 150.

  The rotational state of engine 150 is influenced not only by the rotational state of motor generators MG1 and MG2, but also by the state of the vehicle's travel path (such as unevenness on the road surface). The rotational fluctuation of the shaft 112 can be excluded from the rotational state of the crankshaft 156 as the elastic force generated in the damper 157. Therefore, even in this case, since only the fluctuation in the rotational state of engine 150 based on the true combustion state can be detected, it is possible to accurately detect abnormality of engine 150.

  Furthermore, according to the engine torque estimation calculation means according to the present embodiment, it is possible to accurately detect fluctuations in the rotational state of engine 150 based on the estimated output torque of engine 150. The combustion state can be stabilized by feeding back the fluctuation of the rotation state of the engine 150 to the fuel injection control and the ignition timing control.

  If the engine torque is estimated for each cylinder, the engine torque deviation between the cylinders can be extracted. Therefore, fuel injection control and ignition timing control may be individually performed for a plurality of cylinders. It becomes possible.

  FIG. 9 is a flowchart for explaining an operation of detecting an abnormality of engine 150 according to the present embodiment.

  Referring to FIG. 9, when a series of operations is started, control device 180 adds absolute twist angle Δθa and relative twist angle Δθr calculated by the above-described method by using equation (5). A damper twist angle Δθd is calculated (step S31).

  Next, the control device 180 calculates the elastic force generated in the damper 157 based on the damper twist angle Δθd (step S32). The control device 180 corrects the engine torque Te by adding the elastic force generated by the damper 157 as a correction term to the engine torque Te estimated from the rotational angular acceleration dωe / dt of the crankshaft 156 ( Step S33).

  Then, control device 180 determines whether or not corrected estimated engine torque TE is smaller than a predetermined threshold (step S34). When the estimated engine torque TE is smaller than the predetermined threshold value, the control device 180 determines that an abnormality accompanying misfire has occurred in the engine 150 (step S35). On the other hand, when the estimated engine torque TE is equal to or greater than the predetermined threshold, the control device 180 determines that the engine 150 is normal (step S36).

  The detection of abnormality of the engine 150 by the control device 180 is actually executed by a CPU (Central Processing Unit), and the CPU reads a program including each step shown in FIG. 9 from a ROM (Read Only Memory), Each step shown in FIG. 9 is executed to determine whether the engine 150 is abnormal.

  Accordingly, the ROM corresponds to a computer (CPU) readable recording medium that records a program for causing the computer (CPU) to execute control for detecting an abnormality in the engine 150.

[Example of change]
FIG. 10 is a partially enlarged view of a power output apparatus for a hybrid vehicle to which an abnormality detection apparatus for an internal combustion engine according to a modification of the embodiment of the present invention is applied. In the power output apparatus according to this modification, the rotation speed sensor 184 for detecting the rotation angle of the input shaft 127 is lubricated to the planetary gear 120 by driving the torque of the input shaft 127 with the drive shaft connected to the input shaft 127. The rotational speed sensor 169 (FIG. 1) is different from the previous embodiment in which the input shaft 127 is provided in the oil pump 182 that supplies oil. About another structure, it is the same as that of the above-mentioned embodiment. Therefore, detailed description thereof will not be repeated.

  According to this modification, the rotation speed sensor 184 is provided on the drive shaft of the oil pump 182 that is arranged coaxially with the input shaft 127. The rotation speed sensor 184 is composed of the same magnetic pickup sensor as the crank angle sensor 159 and has an angular resolution equivalent to that of the crank angle sensor 159.

  Then, the rotation speed sensor 184 outputs a rotation pulse signal NI that rises at every predetermined angular period in accordance with the rotation position of the drive shaft (that is, the input shaft 127). Upon receiving the rotation pulse signal NI, the control device 180 generates a 30 ° CA signal NI2 as a pulse signal with a period during which the drive shaft rotates 30 ° as one cycle by the method described above.

  That is, according to this modification, the rotation angle of the input shaft 127 is detected through the rotation state of the oil pump 182 that is arranged coaxially with the input shaft 127. According to this, since the freedom degree of arrangement | positioning of a rotation speed sensor is raised, the enlargement of a power output device can be suppressed by arrange | positioning a rotation speed sensor efficiently.

  When control device 180 (FIG. 1) receives rotation pulse signal NI from rotation speed sensor 184, control device 180 (FIG. 1) generates 30 ° CA signal NI2 for input shaft 127 by the method described above. Then, the twist angle of the damper 157 is calculated based on the generated 30 ° CA signal NI2 and the 30 ° CA signal NE2 for the crankshaft 156.

  The rotational speed sensor 184 only needs to have the same level of resolution as the crank angle sensor 159. For example, the rotational speed sensor 184 calculates the rotational angle by detecting the teeth of the gear member included in the oil pump 182. Alternatively, the rotation angle may be calculated based on the discharge pressure of the oil pump 182.

  In addition to the configuration shown in FIG. 1, various configurations are possible as the configuration of the hybrid vehicle to which the present invention is applied. In FIG. 1, the motor generator MG2 is also coupled to the ring gear shaft 126, but the present invention can be applied to a configuration in which the motor generator MG2 is not coupled. In addition, motor generator MG2 may be directly coupled to crankshaft 156 of engine 150 instead of ring gear shaft 126. Even in such a configuration, the rotational state of the engine 150 is affected by fluctuations in the rotational state of the motor generator, and therefore the present invention can be applied.

  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.

  The present invention can be applied to a power output apparatus including a plurality of power sources including an internal combustion engine and a vehicle equipped with the power output apparatus.

1 is a schematic block diagram of a power output device for a hybrid vehicle to which an abnormality detection device for an internal combustion engine according to an embodiment of the present invention is applied. FIG. 2 is an enlarged view of the planetary gear shown in FIG. 1 and the engine and motor generator coupled thereto. It is a schematic block diagram of a crank angle sensor and a rotation speed sensor. FIG. 4 is a partially cutaway plan view of the damper shown in FIG. 3. It is a figure for demonstrating the method to calculate the relative twist angle of a damper. It is a flowchart for demonstrating the operation | movement which calculates the relative twist angle of the damper by embodiment of this invention. It is a figure for demonstrating the method to calculate the absolute twist angle of a damper. It is a flowchart for demonstrating the operation | movement which calculates the absolute twist angle of the damper by embodiment of this invention. It is a flowchart for demonstrating the operation | movement which detects the abnormality of the engine by embodiment of this invention. It is the elements on larger scale of the motive power output device of the hybrid vehicle to which the abnormality detection apparatus of the internal combustion engine by the modification of embodiment of this invention is applied.

Explanation of symbols

  100 power output device, 111 power transmission gear, 112 drive shaft, 114 differential gear, 119 case, 120 planetary gear, 121 sun gear, 122 ring gear, 123 planetary pinion gear, 124 planetary carrier, 125 sun gear shaft, 126 ring gear shaft, 127 input shaft, 128 Power take-out gear, 129 Chain belt, 132 Rotor, 133 Stator, 134, 144 Three-phase coil, 135, 145 Permanent magnet, 139, 149 Resolver, 142 Rotor, 143 Stator, 150 Engine, 156 Crankshaft, 157 Damper, 158 Torque limiter, 159 crank angle sensor, 160 driving wheel, 161 torsion member, 162 intermediate member, 164a access Pedal position sensor, 164 Driven wheel, 165a Brake pedal position sensor, 169, 184 Rotational speed sensor, 180 Controller, 182 Oil pump, 185 Shift position sensor, 200 Crank rotor, 202 Teeth, 204 Missing teeth, MG1, MG2 motor generator.

Claims (9)

An abnormality detection device for an internal combustion engine that detects an abnormality of the internal combustion engine in a power output device that outputs power to a drive shaft using an internal combustion engine and a motor generator as a power source,
The power output device is
An input shaft that receives power from the internal combustion engine, a rotating shaft of the motor generator, and the drive shaft are mechanically coupled, and power from the internal combustion engine is mechanically distributed to the motor generator and the drive shaft. A power split mechanism configured to:
A damper coupled between the output shaft of the internal combustion engine and the input shaft for transmitting power while suppressing relative rotation between the output shaft of the internal combustion engine and the input shaft;
The abnormality detection device for the internal combustion engine includes:
Torque estimating means for estimating and calculating the output torque of the internal combustion engine based on the rotational angular acceleration of the output shaft of the internal combustion engine;
First and second rotation angle detecting means for detecting rotation angles of the output shaft and the input shaft of the internal combustion engine, respectively;
Based on the detected rotation angle of the output shaft of the internal combustion engine and the input shaft, the damper is applied to the output shaft of the internal combustion engine so as to suppress relative rotation between the output shaft of the internal combustion engine and the input shaft. Torque correcting means for calculating an elastic force to be corrected, and correcting the estimated output torque of the internal combustion engine based on the calculated elastic force of the damper;
An abnormality detection device for an internal combustion engine, comprising: an abnormality diagnosis unit that diagnoses an abnormality of the internal combustion engine based on the corrected output torque of the internal combustion engine. The damper includes an elastic member that is compressed when an output shaft of the internal combustion engine and the input shaft rotate relative to each other and applies an elastic force to both shafts.
The torque correction means includes
The difference between the rotation angle of the output shaft and the input shaft of the internal combustion engine detected by the first and second rotation angle detection means is acquired as the twist angle between the output shaft of the internal combustion engine and the input shaft. A twist angle acquisition means;
The abnormality detection device for an internal combustion engine according to claim 1, further comprising: an elastic force calculation unit that calculates an elastic force of the damper by multiplying the acquired twist angle by an elastic constant of the elastic member. A signal processing means for receiving the rotation angle of the output shaft of the internal combustion engine from the first rotation angle detection means and receiving the rotation angle of the input shaft from the second rotation angle detection means;
The signal processing means generates and outputs a first pulse signal having a period of rotation of a predetermined first unit angle as one cycle based on a rotation angle of an output shaft of the internal combustion engine, and outputs the first pulse signal. A second pulse signal having a period of rotation of a second unit angle larger than the unit angle as one cycle is generated and output, and the first pulse signal is generated and output based on the rotation angle of the input shaft And generating and outputting the second pulse signal,
The twist angle acquisition means includes
A relative twist angle calculating means for calculating a relative angle of the twist angle in the one cycle based on the first pulse signal for the output shaft and the input shaft of the internal combustion engine;
A twist angle for detecting a reference point of the twist angle based on the second pulse signal for the output shaft and the input shaft of the internal combustion engine when the output torque of the internal combustion engine is substantially zero A reference point detection means;
Absolute twist angle calculation means for calculating an absolute angle of the twist angle based on the detected reference point of the twist angle and the second pulse signal for the output shaft and the input shaft of the internal combustion engine;
The abnormality detection device for an internal combustion engine according to claim 2, further comprising: a twist angle calculation unit that calculates the twist angle by adding the calculated relative angle of the twist angle and the absolute angle. The power split mechanism includes at least three gear elements, and the gear elements include planetary gears connected to the rotation shaft of the motor generator, the drive shaft, and the input shaft, respectively.
The second rotation angle detecting means is provided in an oil pump having a drive shaft connected to the input shaft and driven by torque of the input shaft to supply lubricating oil to the planetary gear. The abnormality detection apparatus for an internal combustion engine according to any one of the above.   The abnormality detection device for an internal combustion engine according to claim 4, wherein the second rotation angle detection means estimates and calculates a rotation angle of the input shaft based on a rotation state of the oil pump. An internal combustion engine abnormality detection method for detecting an abnormality of the internal combustion engine in a power output device that outputs power to a drive shaft using an internal combustion engine and a motor generator as a power source,
The power output device is
An input shaft that receives power from the internal combustion engine, a rotating shaft of the motor generator, and the drive shaft are mechanically coupled, and power from the internal combustion engine is mechanically distributed to the motor generator and the drive shaft. A power split mechanism configured to:
A damper coupled between the output shaft of the internal combustion engine and the input shaft for transmitting power while suppressing relative rotation between the output shaft of the internal combustion engine and the input shaft;
The abnormality detection method for the internal combustion engine includes:
A first step of estimating and calculating the output torque of the internal combustion engine based on the rotational angular acceleration of the output shaft of the internal combustion engine;
A second step of detecting rotation angles of the output shaft and the input shaft of the internal combustion engine,
Based on the detected rotation angle of the output shaft of the internal combustion engine and the input shaft, the damper is applied to the output shaft of the internal combustion engine so as to suppress relative rotation between the output shaft of the internal combustion engine and the input shaft. A third step of calculating an elastic force to be corrected, and correcting the estimated output torque of the internal combustion engine based on the calculated elastic force of the damper;
And a fourth step of diagnosing abnormality of the internal combustion engine based on the corrected output torque of the internal combustion engine. The damper includes an elastic member that is compressed when an output shaft of the internal combustion engine and the input shaft rotate relative to each other and applies an elastic force to both shafts.
The third step includes
A first sub-step for obtaining a difference between a rotation angle of the output shaft of the internal combustion engine and the input shaft detected in the second step as a twist angle between the output shaft of the internal combustion engine and the input shaft; ,
The abnormality detection method for an internal combustion engine according to claim 6, further comprising a second substep of calculating an elastic force of the damper by multiplying the acquired twist angle by an elastic constant of the elastic member. The second step includes
Based on the detected rotation angle of the output shaft of the internal combustion engine, a first pulse signal having a period of rotation of a predetermined first unit angle as one cycle is generated and output, and from the first unit angle Generating and outputting a second pulse signal having a period during which the second unit angle is larger as one cycle;
Generating and outputting the first pulse signal based on the detected rotation angle of the input shaft, and generating and outputting the second pulse signal;
The first sub-step includes
Based on the first pulse signal for the output shaft and the input shaft of the internal combustion engine, based on the first pulse signal for the output shaft and the input shaft of the internal combustion engine, the twist angle in the one cycle Calculating a relative angle;
Detecting a reference point of the twist angle based on the second pulse signal for the output shaft and the input shaft of the internal combustion engine when the output torque of the internal combustion engine is substantially zero; ,
Calculating an absolute angle of the twist angle based on the detected reference point of the twist angle and the second pulse signal for the output shaft and the input shaft of the internal combustion engine;
A relative twist angle between the output shaft of the internal combustion engine and the input shaft is calculated including a twist angle calculation means for calculating the twist angle by adding the calculated relative angle of the twist angle and the absolute angle. An abnormality detection method for an internal combustion engine according to claim 7, comprising the step of: The power split mechanism includes at least three gear elements, and the gear elements include planetary gears connected to the rotation shaft of the motor generator, the drive shaft, and the input shaft, respectively.
In the second step, the rotation angle of the input shaft is determined based on the rotational state of an oil pump that is connected to the input shaft and is driven by the torque of the input shaft to supply lubricating oil to the planetary gear. The abnormality detection method for an internal combustion engine according to any one of claims 6 to 8, wherein an estimation calculation is performed.

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