JP4508036B2 - Rotation angle detector - Google Patents

Description

  The present invention relates to a rotation angle detection device that takes in outputs of a crank angle sensor that detects a plurality of detected portions that rotate in synchronization with rotation of a crankshaft of an internal combustion engine and detects the rotation angle of the crankshaft.

  As this type of rotation angle detection device, an output shaft (detected portion) is detected by detecting a plurality of teeth (detected portions) formed at equal intervals on a rotor provided on the crankshaft based on the output of the crank angle sensor. A device that detects the rotation angle of the crankshaft) is well known. However, there are usually structural errors in the spacing between actual teeth. If there is a structural error, an error occurs in detection of the rotation angle of the crankshaft.

  Therefore, conventionally, for example, as seen in Patent Document 1 below, the time required for rotation of a section defined by two teeth is detected, and the detected time is compared with the theoretical time to compare the two teeth. An apparatus for detecting an angular error between the two has also been proposed. Here, the theoretical time is defined for each section in which a region of one rotation of the crankshaft is divided into a plurality corresponding to the teeth. According to this apparatus, even if the rotational speed of the crankshaft periodically changes every “360 ° CA”, the influence of this periodic change can be eliminated when the angle error is detected.

  However, the actual rotational speed of the crankshaft does not necessarily change periodically every “360 ° CA”. For this reason, the difference between the detected time and the theoretical time includes the influence of the rotational fluctuation of the crankshaft that does not have a period of “360 ° CA”. Therefore, what is detected as an angle error by the above-mentioned device includes the effect of crank shaft rotation fluctuation that does not actually have a period of “360 ° CA”, so that the angle error can be detected with high accuracy. Making it difficult.

As the rotation angle detection device, there are, for example, Patent Document 2 and Patent Document 3 in addition to Patent Document 1.
JP-A-11-247707 JP 10-122031 A Japanese Patent Laid-Open No. 10-73613

  The present invention has been made to solve the above-described problems, and an object of the present invention is to accurately detect an angular error of the crankshaft caused by the structure of the detected portion that rotates in synchronization with the rotation of the crankshaft. An object of the present invention is to provide a rotation angle detection device capable of performing

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

According to a first aspect of the present invention, the fuel cut control for stopping the fuel injection that generates the torque of the crankshaft is performed, and the crankshaft is rotated once , twice, or according to the rotation angle of the crankshaft. When there is a member that applies a periodically changing force to the crankshaft, the force cycle, a common multiple of the force cycle and “360 ° CA”, or a common multiple of the force cycle and “720 ° CA” Is divided into a plurality of sections using the detected part, and the rotation of all of the plurality of sections is performed based on the output of the crank angle sensor during the fuel cut control. a calculating means for calculating a time required for all of the plurality of sections, an averaging means for calculating a plurality of average value of the calculated value by the pre-Symbol calculating means respectively, said plurality of sections And the total interval averaging means for calculating an entire section average value obtained by averaging the average value, based on a comparison between said average value and said entire section average value of an arbitrary section of the plurality of sections, of the arbitrary section And an error detection means for detecting an angle error.

  In the above configuration, when the crankshaft is rotated by a crank angle that is an integral multiple of the entire section (corresponding to the plurality of sections), the calculated value of the time required for each rotation of the plurality of sections is calculated by the integral number of times. Is done. Then, the average value of the calculated values is calculated for each of the plurality of sections by the averaging means. Here, the structural angular error of the arbitrary section with the at least one section as a reference appears as a deviation of the average value of the arbitrary section from the average value of the at least one section. . Therefore, an angle error in an arbitrary section can be detected by comparing these average values.

  Further, each of the average values is an average of crankshaft rotation fluctuations. For this reason, by using these average values, it is possible to suitably suppress the influence of fluctuations in the rotation of the crankshaft due to complex forces applied to the crankshaft, noise mixed in the output of the crank angle sensor, etc., when detecting the angle error. Can do.

In particular, in the above configuration, the average value of all sections is compared with the average value of an arbitrary section. This means that the reference for the time required for rotation of each section is the average value of all the sections. Therefore, the reference can be obtained by averaging rotation fluctuations during one or more rotations of the crankshaft, and thus can be set to an appropriate value as the time required for the rotation of the section.

According to a second aspect of the invention of claim 1 Symbol placement, further storage means for storing a reference model defining the criteria for the deviation between said average value and said entire section average value of the arbitrary section And the error detection means removes a deviation determined by the reference model from a deviation between the average value of the arbitrary section and the average value of all the sections when detecting the error. .

  In the above configuration, the fluctuation of the force applied to the crankshaft with the rotation of the crankshaft tends to some extent, for example, 4 strokes as one cycle. For this reason, by using the reference model, it is possible to suitably remove the influence of the crankshaft rotational fluctuation due to the force assumed as the force applied to the crankshaft from the detected deviation.

  In the above configuration, the force applied to the crankshaft during the fuel cut control tends to be different depending on the model of the internal combustion engine. For this reason, the crank shaft rotation fluctuation during fuel cut control also tends to be different for each type of internal combustion engine. In this regard, according to the above configuration, it is also possible to determine the deviation assumed from the tendency of the rotation fluctuation when the rotation of the crankshaft fluctuates due to the force applied to the crankshaft by the reference model. Then, by using the reference model that determines the deviation caused by the crankshaft rotation fluctuation, the influence of the crankshaft rotation fluctuation can be eliminated when the angle error is detected.

The invention according to claim 3 is the invention according to claim 2 , wherein the internal combustion engine is a four-stroke engine and has a camshaft mechanically connected to the crankshaft, and is determined by the reference model. The deviation that is generated includes a deviation that is caused by a periodical force having the four strokes as one cycle applied to the crankshaft.

  In the above configuration, the combustion cycle is completed by four strokes, that is, two rotations of the crankshaft. For this reason, the timing of opening and closing the intake valve and the exhaust valve connected to the camshaft is a 4-stroke cycle. In the compression process and the exhaust process, the force applied to the piston at the time of displacement to the top dead center of the piston is different, so the force applied to the crankshaft is also different. For this reason, due to the combustion cycle, a periodic force with four strokes as one cycle is applied to the crankshaft. Here, in the above configuration, by including the deviation caused by the application of the periodic force in the reference model, the influence of the rotational fluctuation due to the periodic force is preferably removed when detecting the angle error. Can do.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the entire section is one rotation of the crankshaft.

  In the above configuration, since one rotation of the crankshaft is defined as the entire section, the minimum necessary section is defined when calculating the angle error using the detected portion. For this reason, it is possible to reduce the calculation load when calculating the angle error, and it is possible to reduce the memory capacity used for the calculation.

Further, the interval average value of the time necessary for the rotation of one rotation of the crank shaft, so that the defined as criteria for detecting the angular error of the arbitrary section. On the other hand, the rotation fluctuation of the crankshaft can be closely approximated by the fluctuation with a cycle of one rotation of the crankshaft. For this reason, the reference | standard in which the influence of the rotation fluctuation | variation was suppressed suitably can be defined by making into a reference | standard the area average value of the time which rotation for one rotation requires.

The invention according to claim 5 is the invention according to any one of claims 1 to 3 , wherein the internal combustion engine is a four-stroke engine and has a camshaft mechanically connected to the crankshaft. The entire section is two revolutions of the crankshaft.

  In the above configuration, the combustion cycle is completed by four strokes, that is, two rotations of the crankshaft. For this reason, the timing of opening and closing the intake valve and the exhaust valve connected to the camshaft is a 4-stroke cycle. In the compression process and the exhaust process, the force applied to the piston at the time of displacement to the top dead center of the piston is different, so the force applied to the crankshaft is also different. For this reason, due to the combustion cycle, a periodic force with four strokes as one cycle is applied to the crankshaft. For this reason, in the said structure, only the influence of the same phase component of the said periodic force will be superimposed on the time required for rotation of arbitrary sections, and its average value. For this reason, when detecting the angle error, it is possible to grasp the influence of the periodic force.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein a plurality of detected parts in which the internal combustion engine rotates in synchronization with a camshaft mechanically connected to the crankshaft are provided. The cam angle sensor for detecting the detection value is divided into a plurality of cam-side sections by the detected portion provided on the camshaft as the entire section for two rotations of the crankshaft. By performing the same processing as the processing by the calculating means, the averaging means and the error detecting means using the section, a cam side detecting means for detecting an angle error in the cam side section, and a cam side detecting means And a correction means for correcting the detection result of the error detection means based on the detection result.

  In the above configuration, the cam shaft angle error is detected in the same manner as the crank shaft angle error. Then, by comparing the section angles on which the angle error has been corrected for the sections on the camshaft and the corresponding sections on the crankshaft, it is possible to grasp the mutual reliability of the corrected section angles. it can. Thus, the detection result of the error detection means can be corrected based on the detection result of the cam side detection means.

  In addition, if the process performed by the cam side detection means, that is, the same process as the calculation means, the averaging means, and the error detection means, is the process described in any one of claims 1 to 4 and 6. Good.

(First embodiment)
Hereinafter, a first embodiment in which a rotation angle detection device according to the present invention is applied to a rotation angle detection device of a diesel engine mounted on a manual transmission vehicle will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of the engine system.

  The illustrated diesel engine 1 is configured as a multi-cylinder internal combustion engine (assuming four cylinders here), and includes an actuator such as a fuel injection valve 2 for each cylinder. The piston 3 of each cylinder is connected to the crankshaft 5 via a connecting rod 4. The crankshaft 5 is mechanically connected to the camshafts 6 and 8. The cam shafts 6 and 8 rotate once while the crankshaft 5 rotates twice. That is, the diesel engine 1 is a 4-stroke engine. The crankshaft 5 can be connected to drive wheels via a manual transmission (MT10). On the other hand, the shift operation unit 12 is a portion where the shift position is operated by the user, and the shift position of the MT 10 is changed by the operation of the shift operation unit 12. The shift operation unit 12 includes a shift position sensor 14 that detects a shift operation position.

  The crankshaft 5 is provided with a rotor 20 as shown enlarged on the left side in the drawing. The rotor 20 is formed with a plurality of detected portions (tooth portions 22). Specifically, the rotor 20 is basically formed with tooth portions 22 at equal intervals (here, “30 ° CA” is illustrated), and a missing tooth portion 24 is provided at one location of the rotor 20. ing.

  On the other hand, the camshaft 6 is provided with a rotor 30. The rotor 30 is also formed with a plurality of detected portions (tooth portions 32). Incidentally, here, an example in which the four tooth portions 32 are formed at equal intervals is shown.

  The tooth portion 22 is detected by a crank angle sensor 40. On the other hand, the tooth portion 32 is detected by a cam angle sensor 42.

  The electronic control unit (ECU 50) includes a central processing unit (CPU 52), a read only memory (ROM 54), an electrically rewritable read only memory (EEPROM 56), and the like. The ECU 50 captures detection values of sensors for detecting various operating states of the diesel engine, such as the crank angle sensor 40 and the cam angle sensor 42, and detection values for requests from the user, such as the shift position sensor 14. . And ECU50 controls the output of the diesel engine 1 by operating various actuators, such as the fuel injection valve 2, based on these detection results.

  Various programs are stored in the ROM 54 in order to appropriately perform the output control. As this program, for example, a fuel injection learning program 60 for calculating a learning value for compensating variation in the injection characteristic of the fuel injection valve 2 of each cylinder, or a structural error in the interval between the tooth portions 22 is compensated. There is a crank angle error learning program 62.

  The learning value is calculated by the fuel injection learning program 60 in the following procedure. (A) The operation amount of the fuel injection valve 2 in each cylinder is set so that the difference in the amount of increase in the rotational speed of the crankshaft 5 associated with fuel injection in each cylinder is zero. (A) The difference between the reference operation amount and the operation amount obtained in the step (a) is set as a learning value for each cylinder.

  By using the learning value calculated by the above procedure, the amount of increase in the rotational speed calculated based on the output of the crank angle sensor 40 can be made substantially equal. However, when there is a structural error in the interval between the tooth portions 22, the rotation angle and rotation speed calculated based on the output of the crank angle sensor 40 are deviated from the actual rotation angle and rotation speed. It will be. When the deviation occurs, the variation in the injection characteristic of the fuel injection valve 2 of each cylinder cannot be compensated depending on the learning value obtained in the step (a).

  Therefore, in the present embodiment, first, a learning value that compensates for a structural error in the interval between the tooth portions 22 is calculated using the crank angle error learning program 62. This will be described in detail below. Here, first, the structural error of the interval between the tooth portions 22 will be described with reference to FIG.

  In FIG. 2 (a), for the rotor 20 provided on the crankshaft 5, a section defined by the tooth portions 22 on both sides of the missing tooth portion 24 is defined as a section A 0, and every “60 ° CA” in order clockwise. Sections A1 to A5 are defined. In FIG. 2A, since the tooth portion 22 is not displaced, the sections A0 to A5 are all equal to each other. On the other hand, sections A2 ′ and A3 ′ show a case where a shift occurs in sections A2 and A3 due to a shift in tooth portion 22.

  FIG. 2B shows the rotational speed detected in the sections A0 to A5 during the fuel cut control for stopping the fuel injection that contributes to the generation of the torque of the crankshaft 5 of the diesel engine 1. FIG. 2C shows the time (elapsed time) required for the rotation of the sections A0 to A5 during the fuel cut control. 2 (b) and 2 (c) schematically show a solid line when there is no structural shift in the interval between the tooth portions 22. FIG. As shown in the drawing, since the fuel cut control is performed, the rotation speed is gradually decreased, and the elapsed time is gradually increased. On the other hand, the rotational speed detected when the above-described structural deviation occurs in the interval between the tooth portions 22 is shown by a one-dot chain line in FIG. As shown in the figure, the rotation speed once increases in the section A2 ′ and becomes smaller than the actual value in the section A3 ′. Moreover, the elapsed time detected when the above-mentioned structural shift | offset | difference arises in the space | interval between the tooth parts 22 is shown with a dashed-dotted line in FIG.2 (c). As shown in the figure, the elapsed time once decreases in the section A2 ′ and becomes larger than the actual value in the section A3 ′.

  In order to compensate for the structural angular error of the spacing between the tooth portions 22, it is desirable to learn a learning value that compensates for this. However, the actual rotation of the crankshaft 5 is fluctuated by the force applied to the crankshaft 5 and noise is mixed into the output of the crank angle sensor 40, which hinders the learning value from being learned accurately. This will be described in detail below.

  FIG. 3 shows fluctuations in the rotational speed of the crankshaft 5 during fuel cut control. In FIG. 3, the first to fourth cylinders are indicated by “# 1 to # 4”, and each of these combustion cycles is indicated together with the fluctuations in the rotational speed. Incidentally, since the fuel cut control is assumed, the “combustion stroke” is not shown. Here, the decrease in the rotational speed due to the fuel cut control is shown neglected for convenience.

  As shown in the figure, the rotational speed is periodically minimized near the compression top dead center of each cylinder. However, this does not mean that a periodic force having a period at which compression top dead center is applied is applied to the crankshaft 5. For example, at “180 ° CA”, the compression top dead center of the second cylinder is used, so that the force of the piston 3 of the second cylinder for suppressing the rotation of the crankshaft 5 via the connecting rod 4 is particularly strong (peak). Become). Further, at “360 ° CA”, since the compression top dead center of the first cylinder, the force that the piston 3 of the first cylinder tries to suppress the rotation of the crankshaft 5 through the connecting rod 4 is particularly strong ( Peak). The peak positions are different from each other on the crankshaft 5 so that the peak positions of the forces applied to the crankshaft 5 at the compression top dead center of each cylinder are shown in the lower part of the figure. This is because the connecting rod 4 connected to the piston 3 of each cylinder is connected to the crankshaft 5 at different locations.

  For this reason, the torsional force of the crankshaft 5 due to the force that the crankshaft 5 continues to rotate due to inertia after the fuel cut control and the force that the piston 3 of each cylinder tries to restrain the crankshaft 5 via the connecting rod 4 And the torsional force has a period of “720 ° CA”.

  More strictly, as shown in FIG. 4, the rotational fluctuation is attenuated as the rotational speed of the crankshaft 5 decreases. Here, the torsional force is also attenuated. Further, for example, at “180 ° CA”, the torsional force generated by the depressing force applied to the crankshaft 5 by the piston 3 of the second cylinder via the connecting rod 4 and the inertial force of the crankshaft 5 is the elasticity of the crankshaft 5. For example, this also causes a reverse twisting force applied to the crankshaft 5 thereafter.

  As described above, the force applied to the crankshaft 5 during the fuel cut control fluctuates in a complicated manner, whereby the rotational speed of the crankshaft 5 also fluctuates in a complicated manner. In the present embodiment, when detecting the structural error of the interval between the tooth portions 22, the influence of such fluctuations is suppressed as much as possible, and the influence of noise mixed in the output of the crank angle sensor 40 is suppressed as much as possible. Therefore, the average value of the time required for the rotation of the sections A0 to A5 is used.

  That is, first, the calculated value Ti_j (j = 1 to n) of the time required for the rotation of the section Ai (i = 0 to 5) is calculated. Here, “j” is a sampling number, and adjacent values indicate that they are sampled at timings adjacent to each other. Then, as shown in FIG. 5A, an average value Tib of the calculated values Ti_j in each of the sections Ai is calculated.

  Next, as shown in FIG. 5 (b), an average value Tba of all sections obtained by averaging the average values Tib is calculated, and a ratio kTi of each average value Tib to the average value of all sections Tba is calculated.

  At this time, each ratio kTi is a good approximation of the structural error of each section Ai. That is, each average value Tib is an average of a plurality of calculated values of the time required for the rotation of each section Ai. Therefore, the influence of noise mixed in the output of the crank angle sensor 40 and the rotation of the crankshaft 5 are started. It is a value in which the influence of attenuation and the influence of rotational fluctuation are suppressed. The average value kTa for all sections is an average value of rotation of “360 ° CA × n”. Therefore, the influence of noise mixed in the output of the crank angle sensor 40 and the attenuation of the rotation of the crankshaft 5 are started. It is a value in which the influence and the influence of the rotation fluctuation are suppressed. For this reason, the average value Tba of all the sections is an appropriate value as a reference value for the time required for the rotation of each section Ai, and the ratio kTi is obtained by quantifying the deviation from the reference. For this reason, this deviation | shift amount is a thing with a sufficient precision as a value which quantified the structural error of each area Ai.

  However, the ratio kTi includes these influences, although the influence of fluctuations in the force applied to the crankshaft 5 is suppressed. Therefore, in the present embodiment, the ratio kTi is corrected using the reference model shown in FIG. Here, the reference model basically determines the ratio of the time required for the rotation of each section Ai to the rotation time per each section averaged over all sections when there is no structural error. is there.

  As shown in FIG. 5C, the reference model includes reference ratios kTni corresponding to the respective sections Ai. These reference ratios kTni are set to values assumed as the ratio kTi of each average value Tib with respect to the total average value Tba when there is no structural error. The final learning value kTif is calculated by dividing the ratio kTi by the reference ratio kTni.

  By using the learning value kTif, the structural error in the section Ai can be compensated. That is, for example, when the time Ti required for the section Ai is detected, the true time compensated for the error can be learned and corrected as “Ti / kTif”.

  Hereinafter, the processing procedure of the learning control will be described with reference to FIG. The procedure of this process is defined in the crank angle error learning program 62. This process is actually repeatedly executed by the ECU 50 (the CPU 52) with a flag process and the like at a predetermined crank angle cycle.

  In this series of processing, first, in step S10, it is determined whether or not the section Ai detected by the crank angle sensor 40 is the section A0. When the section Ai is not the section A0, this series of processes is temporarily ended. On the other hand, if it is determined that the section Ai is the section A0, the process proceeds to step S12. In step S12, it is determined whether or not a learning condition is satisfied. The learning conditions are (a) the shift operation unit 12 is operated in the neutral range, (b) the rotational speed is within a predetermined range (NE0 or more, NE1 or less), and (c) the fuel cut control is performed. All the conditions of what is being done hold.

  Here, the condition (A) is for performing the learning control under the condition that the torque applied to the crankshaft 5 from the drive wheel side is substantially zero. By satisfying this condition, it is possible to avoid fluctuations in the torque applied to the crankshaft 5 due to torque fluctuations applied from the drive wheel side. The condition (b) is for performing the learning control under a condition where the fluctuation of the torsional force applied to the crankshaft 5 does not become excessively large. Here, the upper limit value NE1 is set based on the lower limit value of the rotation speed at which the fluctuation of the torsional force becomes excessively large and the rotation fluctuation of the crankshaft 5 can significantly affect the learning control accuracy. Condition (c) is for avoiding rotational fluctuation of the crankshaft 5 due to the combustion process. Incidentally, fuel cut control is performed at the time of vehicle deceleration or the like.

  When the learning condition is satisfied, the process proceeds to step S14. In step S14, a time Ti required for the rotation of the section Ai is calculated. This process is performed until the crankshaft 5 makes one revolution (step S16: YES). And if the time which each rotation of the area A0-A5 is calculated by one rotation of the crankshaft 5 is calculated, it will transfer to step S18. In the processing of steps S18 to S24, “n” integrated values of the time required for the rotation of each section A0 to A5 are calculated in order to calculate “n” average values of the time required for the rotation of each of the sections A0 to A5. This is a calculation process.

  Then, when “n” integrated values of the time required for the rotation of each section A0 to A5 are calculated, the process proceeds to step S26. The processing of steps S26 to S32 is to calculate “n” average values Tib of the time required for rotation of each of the sections A0 to A5, and an entire section average value Tba that is an average value of these average values Tib. . Then, when each of the average values Tib and the total average value Tba is calculated, the process proceeds to step S34. The processes in steps S34 to S38 are processes for calculating the final learning value kTif. Here, each reference ratio kTni is desirably taken out from the EEPROM 56. That is, it is desirable to store only the program for defining the processing procedure shown in FIG. 6 in the ROM 54 of the ECU 50 and store the reference ratio kTni in the EEPROM 56 according to the model of the diesel engine 1. Thereby, it becomes easy to use each different reference ratio kTni for each model of the diesel engine 1.

  Each of the reference ratios kTni is a value assumed when there is no structural error between the tooth portions 22 and measurement of the time required for the rotation of each of the sections A0 to A5 is started from the section A0. Set.

  When the processing from step S34 to S38 is completed, in step S40, the learning value kTif is stored in the EERPOM 56, and this series of processing is temporarily terminated.

  When it is determined in step S12 that the learning condition is not satisfied, in step S42, variables used in the series of processes are initialized, and the series of processes is temporarily ended.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) The angle error of these sections A0 to A5 was detected using “n” average values Tib of the time required for the rotation of each section A0 to A5. Each of these average values Tib is obtained by averaging the outputs of the crank angle sensor 40. For this reason, in particular, the rotational fluctuations of the crankshaft 5 are averaged. Therefore, by using these average values Tib, the influence of noise mixed into the output of the crank angle sensor 40 and the fluctuation of the rotation of the crankshaft 5 due to a complicated force applied to the crankshaft 5 are suitably suppressed when detecting the angle error. can do.

  (2) The structural error of each section Ai was calculated based on the ratio of each average value Tib to the total section average value Tba obtained by averaging the average values Tib. For this reason, the reference of the time required for the rotation of each section Ai can be obtained by averaging the rotational fluctuations during one rotation of the crankshaft 5, and as a result, the accuracy as a reference for the time required for the rotation of the section. A good value of can be used.

  (3) The average value Tib of each section Ai with respect to the entire section average value Tba, using a normative model that establishes a criterion for the time shift required for the rotation of each section Ai with respect to the rotation time per section averaged by all sections. The above deviation was removed from the ratio kTi. Thereby, the influence of the rotation fluctuation | variation of the crankshaft 5 can be excluded more suitably. In particular, this makes it possible to suitably remove the influence of rotational fluctuations caused by a periodic force having a 4-stroke cycle when calculating the learning value.

  (4) The start of calculation of the time required for rotation of each section Ai is fixed to a predetermined section (here, section A0). Thereby, the normative model (reference ratio kTni) can be set as a value assumed when measurement is started from a predetermined interval, and the normative model can be set with higher accuracy.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, two rotations of the crankshaft 5 are defined as all sections, which are divided into sections A0 to A5 and sections A6 to A11. Here, “Ap = Ai + 360 ° CA (i = 0 to 5, p = 6 to 11)”. In setting the section Aq (q = 0 to 11), the cam angle based on the output of the cam angle sensor 42 is used in addition to the crank angle based on the output of the crank angle sensor 40. Then, as shown in FIG. 7A, “n” times Tq_j (q = 0 to 11, j = 1 to n) required for the respective rotations of these sections A0 to A11 are sampled. “N” average values Tqb are calculated.

  Here, since each average value Tqb is an average of “n” calculated values of time, the influence of noise mixed in the output of the crank angle sensor 40 is sufficiently suppressed. Moreover, although the influence of the rotational fluctuation of the crankshaft 5 is included, this is sufficiently suppressed. Examples of the rotational fluctuation include a periodic force applied to the crankshaft 5 in the above-described four-stroke cycle. However, with respect to this periodic force, the forces in different phases of this force are not averaged and reflected in each average value Tqb. That is, each average value Tqb reflects only the influence of the specific phase portion of the periodic force. Incidentally, here, a phase shifted by an integral multiple of “720 ° CA” is defined as the same phase.

  Subsequently, as shown in FIG. 7 (b), an average value Tba of all sections, which is an average value of each average value Tqb, is calculated, and a ratio kTq of each section Tqb to the average value Tba of all sections is calculated. Further, as shown in FIG. 7C, the ratio between each ratio kTq and the normative model (reference ratio kTnq) is calculated as a final learning value kTqf.

  The normative model according to the present embodiment is a standard that is assumed as a ratio of the average value of the time required for rotation of each section A0 to A11 with respect to the average value of all sections when there is no structural error in the interval between the tooth portions 22. Value. For this reason, in this reference model, the reference ratios kTni of the sections separated from each other by “360 ° CA” are defined separately. Therefore, it is avoided that components having different phases among the periodic forces are averaged and reflected in the reference ratio kTni of each section, and the influence of forces having different phases is different from each other in the reference ratio kTni. It is reflected in. Therefore, the periodic force can be more appropriately reflected in the reference model.

  Then, by calculating the learning value kTif for each of the sections A0 to A11, when calculating the learning value kTif, the influence of the periodic force applied to the crankshaft 5 in the 4-stroke cycle is more accurately removed. be able to.

  If the learning value kTif calculated in this way is learned with high accuracy, the difference between the sections Ai and Ap (p = i + 6) separated from each other by “360 ° CA” becomes substantially zero. These learning values kTif may be used separately for each corresponding crank angle section, but learning values kTiff (i = 0 to 5) that are finally used from those separated by “360 ° CA” from each other. May be calculated. The final learning value kTiff may be an average of the learning values kTif and kTpf in the section separated by “360 ° CA” from each other. However, if either one tends to include more learning errors, the final learning value kTiff may be calculated by weighted averaging of these learning values kTif and kTpf.

  According to the present embodiment described above, in addition to the effects according to the above (1) to (4) of the first embodiment, the following effects can be further obtained.

  (5) Two rotations of the crankshaft 5 are defined as all sections, and a learning value kTqf is calculated for each section A0 to A11. Thereby, the influence of the periodic force applied to the crankshaft 5 in a 4-stroke cycle can be more suitably removed when calculating the learning value.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the second embodiment.

  FIG. 8 shows an outline of calculation of learning values in the present embodiment. As shown in FIGS. 8A and 8B, the average value Tqb and the ratio kTq are calculated for each of the sections A0 to A11 also in this embodiment. However, in this embodiment, the normative model is not used. Instead, in this embodiment, as shown in FIG. 8C, from the ratios kTi and kTp of the sections Ai and Ap (p = i + 6, i = 0 to 5) separated from each other by “360 ° CA”. Then, the learning value kTif for the section Ai is calculated.

  That is, in the sections Ai and Ap that are separated from each other by “360 ° CA”, the phase of the periodic force applied to the crankshaft 5 in the four-stroke cycle is different from each other. The difference in force applied to the crankshaft 5 due to the difference in the phase of the periodic force is reflected. For this reason, the influence of the periodic force itself can be detected from this deviation. In view of this point, the learning value kTif is calculated from the ratios kTi and kTp (kTif = Fi (kTi, kTp)).

  Incidentally, this map Fi may be created in advance by experiments or the like, but based on the comparison with the ratios kTi and kTp, for example, the smaller one of the ratios kTi and kTp is used as the final learning value. A simple setting for calculating the learning value may be used.

  In order to detect the influence of the periodic force, it is desirable to sufficiently suppress the influence of the attenuation of the rotational speed of the crankshaft 5, and therefore the sampling number “n” for calculating the average value is sufficient. It is desirable to make it larger.

  Also according to the present embodiment described in detail above, the effect according to the second embodiment can be obtained.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 9 shows a procedure of processing related to calculation of a learning value for compensating for the crank angle error according to the present embodiment. This process is repeatedly executed by the ECU 50, for example, at a predetermined cycle.

  In this series of processing, first, in step S50, the learning value of the crank angle error is calculated by performing processing similar to the processing shown in FIG. In subsequent step S52, a learning value of the cam angle error is calculated. Here, as shown in FIG. 10 (a), learning values for compensating structural errors in the four sections B0 to B3 defined by the teeth 32 of the rotor 30 provided on the camshaft 6 are used. calculate. Incidentally, cam angle sections B0 and B2 correspond to crank angle sections A0 to A2, and cam angle sections B1 and B3 correspond to crank angle sections A3 to A5.

  The calculation of the learning value for the cam angle error is the same as the process shown in FIG. That is, as shown in FIG. 10A, an average value TrB of a plurality ("m") of times required for rotation of each section Br (r = 0 to 3) is calculated. Then, as shown in FIG. 10 (b), an average value TBa of all sections, which is an average value of these average values TrB, is calculated, and a ratio of each section Br to the average value of all sections TBa is calculated. Further, by dividing this by the reference model (reference ratio BTnr), a learning value BTrf for each section Br is calculated.

  Then, in step S54 shown in FIG. 9, the learning value of the crank angle is corrected based on the learning corrected cam angle.

  If the learning value is correctly learned in steps S50 and S52, the time required for the rotation of the sections B0 and B3 should be the same as the time required for the rotation of the sections A0 to A2. Further, the time required for the rotation of the sections B1 and B3 should coincide with the time required for the rotation of the sections A3 to A5.

For example, it is assumed that the calculated values before learning correction of the time required for the rotation of the sections A0 to A2 during the two rotations of the crankshaft 5 are calculated as the times T0_1 to T2_1 and the times T0_2 to T2_2. In addition, it is assumed that the calculated values before learning of the time required for the rotation of the sections B0 and B2 between the two rotations are calculated as the times TB0 and TB2. However, the time TB0 is calculated based on the output of the crank angle sensor 40 detected before the time TB2. At this time, if these learning values are completely true values, the following relationship is established.

TB0 / BT0f = T0_1 / kT0f + T1_1 / kT1f + T2_1 / kT2f
TB2 / BT2f = T0_2 / kT0f + T1_2 / kT1f + T2_2 / kT2f

The reliability of the learned value of the cam angle error and the learned value of the crank angle error can be quantified by the deviation amount between the right side and the left side of the above two equations. For this reason, in this embodiment, when the right side and the left side do not match, the learned value of the crank angle error and the learned value of the cam angle error are corrected. In this correction, for example, assuming that the average value of the right side and the left side is a true value of the time required for the rotation of the section B0 and the section B2, the learning value is corrected so that the right side and the left side become the true values. Can be done.

  According to this embodiment described above, the following effects can be obtained in addition to the effects (1) to (4) of the first embodiment.

  (6) A learning value for the cam angle error was calculated and used to correct the learning value for the crank angle error. Thereby, the learning value of the crank angle error can be set to a more appropriate value.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the fourth embodiment, the learning value calculation method for compensating for the crank angle error is not limited to that shown in FIG. For example, it may be the one exemplified in the second and third embodiments.

  -The number of cylinders of a multi-cylinder internal combustion engine may be arbitrary. Even in this case, the effects of the above embodiments can be obtained. Further, it may be a single cylinder internal combustion engine. Even in this case, since the combustion cycle is a “720 ° CA” cycle, the methods of the above embodiments are effective.

  The internal combustion engine is not limited to one in which the intake valve and the exhaust valve open and close in conjunction with the rotation of the engine-driven cam. For example, the intake valve or the exhaust valve may be configured by an electromagnetically driven valve. In this case, if the intake valves and exhaust valves of all cylinders are fully opened during fuel cut control, the force applied to the crankshaft 5 by the piston 3 of each cylinder via the connecting rod 4 and the amount of variation thereof can be reduced as much as possible. it can.

  In calculating the learning values for the sections A0 to A5, etc., the learning values are not limited to those set based on the ratio of the average value of each section to the total section average value Tba, but may be set based on the difference. Good. At this time, the normative model is preferably set to a value assumed when there is no structural error in the difference between the average values of the sections with respect to the average value Tba of all sections.

  Even without using the normative model, the effects (1) and (2) of the first embodiment can be obtained.

  -The entire section is not limited to one rotation or two rotations of the crankshaft 5. For example, when there is a member that exerts a force that periodically changes on the crankshaft 5 according to the rotation angle of the crankshaft 5, this cycle, or this cycle and “360 ° CA” or “720 ° CA” It is effective to use a common multiple of

  -Moreover, as a reference | standard at the time of detecting the structure error of the area Ai and the area Ap, it is not restricted to the said all area average value. For example, any one of the sections A0 to A5 may be used as a reference. Even in this case, the relative angular error between the sections can be detected. For this reason, it is possible to compensate for variations in the injection characteristics of the fuel injection valves of each cylinder, for example, using the learning value calculated in this way.

  The method of using the learning value is not limited to learning of the learning value that corrects the variation in fuel injection characteristics. For example, when starting fuel injection at a predetermined crank angle, there is a control to calculate the time from when any of the tooth portions 32 is detected until the predetermined crank angle is reached, and to start fuel injection when the time elapses. . In such a case, it is important to accurately calculate the rotational speed of each section in order to improve the control accuracy of the injection start timing. For this reason, the setting of the injection start timing using the learning value is effective.

  The storage device that stores the reference model and the learning value is not limited to the EEPROM 56. However, it is desirable to use a rewritable nonvolatile memory such as a backup RAM to which power is supplied regardless of whether or not power is supplied to the ECU 30 and a memory (EEPROM or the like) that holds data regardless of whether or not power is supplied. . However, the normative model may be stored in the ROM 54.

  -Not only a manual transmission vehicle but also an automatic transmission vehicle. In this case, for example, the learning control may be performed during fuel cut control during vehicle deceleration.

  -The internal combustion engine is not limited to a diesel engine, and may be a gasoline engine.

  In addition, the structure and number of the detected portion (tooth portion 22) that rotates in synchronization with the rotation of the crankshaft 5 and the detected portion (tooth portion 32) that rotates in synchronization with the rotation of the camshaft 6 are appropriately determined. You may change it.

The figure which shows the whole structure of the engine system in 1st Embodiment. The figure explaining the problem accompanying the structural error between the tooth parts of the rotor provided in a crankshaft. The figure which shows the rotation fluctuation of the crankshaft at the time of fuel cut control. The figure which shows the rotation fluctuation of the crankshaft at the time of fuel cut control. The figure which shows the outline | summary of the learning control of the crank angle error concerning the said embodiment. The flowchart which shows the process sequence of the learning control of the said crank angle error. The figure which shows the outline | summary of the learning control of the crank angle error concerning 2nd Embodiment. The figure which shows the outline | summary of the learning control of the crank angle error concerning 3rd Embodiment. 14 is a flowchart illustrating a processing procedure for crank angle error learning control according to the fourth embodiment. The figure which shows the outline | summary of the learning control of the cam angle error concerning the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 5 ... Crankshaft, 6,8 ... Cam shaft, 20 ... Rotor, 22 ... Tooth part, 30 ... Rotor, 32 ... Tooth part, 40 ... Crank angle sensor, 42 ... Cam angle sensor, 50 ... ECU (Rotation angle detection device) One embodiment).

Claims (8)

In a rotation angle detection device that takes in the output of a crank angle sensor that detects a plurality of detected portions that rotate in synchronization with the rotation of the crankshaft of the internal combustion engine, and detects the rotation angle of the crankshaft,
Means for performing fuel cut control for stopping fuel injection for generating torque of the crankshaft;
When there is a member that exerts on the crankshaft a force that periodically changes according to the rotation angle of the crankshaft, the rotation of the crankshaft, the rotation of the force, All the sections that are defined by the common multiple of “° CA” or the common multiple of the period of the force and “720 ° CA” are divided into a plurality of sections using the detected portion, and the fuel cut control is performed. Based on the output of the crank angle sensor, calculating means for calculating the time required for each rotation for all of the plurality of sections;
For all of the plurality of sections, an averaging means for calculating a plurality of average value of the calculated value by the pre-Symbol calculating means respectively,
An all-section averaging means for calculating an all-section average value obtained by averaging the average values of the plurality of sections;
Rotation angle detection , comprising: error detection means for detecting an angle error of the arbitrary section based on a comparison between the average value of the arbitrary section of the plurality of sections and the average value of all the sections. apparatus. Storage means for storing a normative model that establishes a criterion for a deviation between the average value of the arbitrary section and the average value of all sections;
The error detection unit, when detecting the error, removes a shift determined by the reference model from a shift between the average value of the arbitrary section and the average value of all sections. The rotation angle detection device according to 1. The internal combustion engine is a four-stroke engine and has a camshaft mechanically coupled to the crankshaft;
3. The rotation according to claim 2, wherein the deviation determined by the reference model includes a deviation caused by a periodical force having the four strokes as one cycle applied to the crankshaft. Angle detection device. The rotation angle detection device according to claim 1, wherein the entire section is one rotation of the crankshaft . The internal combustion engine is a four-stroke engine and has a camshaft mechanically coupled to the crankshaft;
The rotation angle detection device according to any one of claims 1 to 3, wherein the entire section is two rotations of the crankshaft . The error detecting means calculates a ratio between the average value calculated by the averaging means and the average value of all the sections in each of the arbitrary section and the section separated by “360 ° CA”. 6. The rotation angle detection device according to claim 5, wherein an angle error of the arbitrary section is detected based on the rotation angle. Means for capturing detection values of a cam angle sensor for detecting a plurality of detected portions in which the internal combustion engine rotates in synchronization with a camshaft mechanically connected to the crankshaft;
Two rotations of the crankshaft are divided into a plurality of cam-side sections by the detected portion provided on the camshaft as the entire section, and the calculation means, the averaging means, and the plurality of cam-side sections are used. Cam side detection means for detecting an angle error of the cam side section by performing the same processing as the processing by the error detection means;
The rotation angle detection device according to claim 1, further comprising a correction unit that corrects a detection result of the error detection unit based on a detection result of the cam side detection unit. The internal combustion engine is a multi-cylinder internal combustion engine;
Means for learning a learning value for correcting variations in the fuel injection characteristics of the fuel injection valve of each cylinder based on the amount of increase in the rotational speed of the crankshaft accompanying the fuel injection of each cylinder of the internal combustion engine;
The learning value for compensating for the error detected by the error detection means is used for learning processing of a learning value for correcting variations in the fuel injection characteristics. The rotation angle detection device according to claim 1.

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