JP2007037335A - Motor controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor controller which can eliminate the discrepancy, without providing a new sensor, etc. even if the counter value of a position counter, which counts the pulse signals from the position sensor, has shifted from the value corresponding to the actual rotating angle of the motor. <P>SOLUTION: Each time the edge of the pulse signal from each electric angle sensor of a brushless motor appears, the difference (Pi-Pi-1) between the counter value Pi-1 of the position counter P at the last appearance of the edge and the counter value Pi of the position counter P at this edge appearance is computed. The difference reflects the slippage, when the counter value of the position counter P has slipped from the value corresponding to the actual rotating angle of the brushless motor. That is, the above difference slips from its normal value J by the amount of the slippage. Then, the counter value of the position counter P is corrected, using the first correction ΔP being the amount of the slippage of the above difference from this normal value J. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a brushless motor control apparatus that is driven to rotate within a predetermined rotation angle range, and more particularly to correction of a counter value of a position counter used for detecting the rotation angle of the motor.

  2. Description of the Related Art Conventionally, a motor such as a brushless motor disclosed in Patent Document 1 is rotationally driven within a predetermined rotation angle range by a motor control device, thereby driving various mechanisms. In this case, in order to accurately drive various mechanisms, it is important to accurately detect the rotation angle of the motor and set the rotation angle to a rotation angle corresponding to the target driving state of the various mechanisms.

Here, as a method of detecting the rotation angle of the motor, an encoder is provided as a position sensor that outputs a pulse signal as the motor rotates, that is, a method of counting pulse signals from the encoder. It is conceivable to adopt a method. According to this method, the value obtained by counting the pulse signal becomes a value corresponding to the rotation angle of the motor, and the rotation angle of the motor can be detected based on the count value of the pulse signal.
JP 2004-194454 A JP 2004-76265 A

  By the way, the count value obtained by counting the edges of the pulse signal from the encoder does not always correspond to the actual rotation angle of the motor, and may deviate from the value corresponding to the actual rotation angle. is there. For example, if noise occurs in the signal output from the encoder, the edge of the noise cannot be distinguished from the edge of the pulse signal from the encoder, and the edge of the noise is mistaken for the edge of the pulse signal. The count value obtained by counting is deviated from the value corresponding to the actual rotation angle of the motor. In this case, the rotation angle of the motor detected based on the count value becomes inaccurate, and even if the motor is driven based on the rotation angle or the like to control various devices to the target driving state, it cannot be performed correctly. The problem that occurs.

  In order to suppress such problems, a deviation amount with respect to the actual motor rotation angle in the count value is obtained, a correction corresponding to the deviation amount is added to the count value, and the count value is converted into the actual motor rotation angle. It is necessary to return to the value corresponding to. For this reason, when a linear sensor or the like for detecting the rotation angle of the motor is separately provided and the rotation angle of the motor detected by the sensor does not correspond to the rotation angle of the motor detected based on the count value, the difference between the two is detected. It is conceivable that a correction value used for correction of the count value is calculated based on the above and the count value is corrected by the correction value. In this case, the deviation from the value corresponding to the actual motor rotation angle in the count value can be eliminated, but for that purpose, a linear sensor or the like must be provided separately, and it takes time to install the linear sensor or the like. A new problem arises that the installation position of the motor is restricted in relation to the installation of the sensor.

  The present invention has been made in view of such a situation, and its purpose is that the counter value of the position counter that coefficients the pulse signal from the position sensor deviates from the value corresponding to the actual rotation angle of the motor. It is another object of the present invention to provide a motor control device that can eliminate the deviation without providing a new sensor or the like.

In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, according to the first aspect of the present invention, a brushless motor that is rotationally driven within a predetermined rotational angle range and a plurality of electrical angle sensors provided in the motor as the brushless motor rotates. The motor is driven by changing the counter value of the electrical angle counter according to the output pattern of the pulse signal output with the phase shifted from, and switching the energized phase of the brushless motor based on the counter value of the electrical angle counter A driving device; and a position sensor that outputs a pulse signal having an edge interval shorter than an edge interval of a pulse signal output from each electrical angle sensor as the brushless motor rotates, and an edge of the pulse signal from the position sensor A motor control device for detecting the rotation angle of the brushless motor based on the counter value of the position counter At each occurrence of an edge of the pulse signal output from each electrical angle sensor, the difference (Pi) between the counter value Pi of the position counter at the time of the current edge generation and the counter value Pi-1 of the position counter at the time of the previous edge generation. -Pi-1), and the rotational state of the brushless motor based on a change in the counter value of the electrical angle counter is any of normal rotation, reverse rotation, and normal / reverse rotation inversion And setting means for variably setting a normal value which is a normal value of the difference (Pi−Pi−1) according to the rotation state of the brushless motor, and the difference (Pi−Pi) with respect to the normal value. -1) as a first correction value, a first correction means for adding a correction for the first correction value to the counter value of the position counter, and a pulse signal output from each electrical angle sensor No When the counter value of the electrical angle counter shows a change that cannot normally occur at the time of occurrence of a shift, a second correction value for invalidating the correction by the first correction means is set, and the second correction Second correction means for adding a correction for the value to the counter value of the position counter.

  When the brushless motor rotates, pulse signals are output from the electrical angle sensor used to drive the motor with the phases shifted from each other. Therefore, if the edge of the pulse signal from each electric angle sensor is counted, the rotation angle of the brushless motor can be roughly detected based on the counted value. However, when high accuracy is required for detection of the rotation angle of the brushless motor, the detection accuracy is insufficient for the rough rotation angle detection as described above. For this reason, a position sensor that outputs a pulse signal at an edge interval shorter than the edge interval of the pulse signal output from each electrical angle sensor as the brushless motor rotates is provided, and the edge of the pulse signal from the position sensor is counted. The rotation angle of the brushless motor is detected based on the counter value of the position counter. As a result, the rotation angle of the brushless motor can be detected with high accuracy.

  By the way, noise is generated in the signal from the position sensor, the edge of the noise is mistakenly recognized as the edge of the pulse signal from the position sensor, and the position counter counts the actual value of the brushless motor. There may be situations where the corner no longer corresponds. In this case, the counter value of the position counter is shifted from a value corresponding to the actual rotation angle of the brushless motor. According to the above configuration, the difference (Pi) between the counter value Pi of the position counter when the current edge occurs in the pulse signal output from each electrical angle sensor and the counter value Pi-1 of the position counter when the previous edge occurs. -Pi-1) reflects the deviation of the counter value of the position counter from the value corresponding to the actual rotation angle of the brushless motor. That is, the difference (Pi-Pi-1) deviates from the normal value by the deviation. Accordingly, the deviation amount of the difference (Pi−Pi−1) from the normal value is set as the first correction value, and the correction corresponding to the first correction value is added to the counter value of the position counter, so that the brushless value in the counter value is increased. Deviation from the value corresponding to the actual rotation angle of the motor can be eliminated. Further, in order to calculate the difference (Pi-Pi-1) for obtaining the first correction value, it is sufficient if there is an electrical angle sensor used for driving the brushless motor, and a new sensor is used to eliminate the deviation. Etc. need not be provided. Note that the normal value for obtaining the first correction value is based on the counter value of the electrical angle counter, which is the rotation state of the brushless motor, that is, whether it is during normal rotation, reverse rotation, or normal / reverse rotation inversion. It is variably set accordingly.

  In addition, noise may occur in the signal from the electrical angle sensor. In this case, the noise may be mistaken as a pulse signal from the electrical angle sensor, and the counter value of the electrical angle counter may change to an incorrect value. When the counter value of the electrical angle counter changes to an incorrect value, the motor rotation state determined based on the counter value is different from the actual state, and the normal value set by the setting means is the actual motor rotation. It will not correspond to the state. Under such circumstances, the first correction value, which is the deviation amount of the difference (Pi−Pi−1) from the normal value, due to the above-described abnormality of the normal value becomes an incorrect value, and the counter of the position counter The erroneous correction corresponding to the first correction value is added to the value. As a result, the counter value of the position counter deviates from a value corresponding to the actual rotation angle of the brushless motor, and the rotation angle of the brushless motor detected based on the counter value becomes an incorrect value.

  However, according to the above configuration, when noise occurs in the signal from the electrical angle sensor and the counter value of the electrical angle counter changes to an incorrect value, the counter value of the position counter is erroneously corrected by the first correction value. Disabled. This is because when the counter value of the electrical angle counter changes to an incorrect value as described above, the counter value shows a change that is not normally possible. When such a change is shown, the correction by the first correction means is performed. This is because a second correction value for invalidating is set, and correction for the second correction value is added to the counter value of the position counter. As described above, since the erroneous correction of the counter value of the position counter by the first correction value is invalidated, the counter value deviates from a value corresponding to the actual rotation angle of the brushless motor, and is detected based on the counter value. It is possible to suppress the rotation angle of the brushless motor from becoming an inaccurate value.

  According to a second aspect of the present invention, in the first aspect of the invention, the second correction means affects the deviation of the counter value of the position counter from the value corresponding to the actual rotation angle of the brushless motor. A value obtained by inverting the sign of the correction value 1 is set as the second correction value.

  According to the above configuration, the second correction value is a value obtained by inverting the sign of the first correction value that affects the deviation of the counter value of the position counter from the value corresponding to the actual rotation angle of the brushless motor. Therefore, by adding the correction for the second correction value to the counter value of the position counter, the erroneous correction of the counter value of the position counter by the first correction unit can be accurately invalidated.

  According to a third aspect of the present invention, in the first aspect of the present invention, the setting means is configured such that the number of edges of the pulse signal output from the position sensor is “between edges of the pulse signal output from the electric angle sensors”. n ”, the brushless motor is based on the fact that the counter value of the electrical angle counter indicates a change in the motor forward rotation direction both when the previous edge is generated from the electrical angle sensor and when the current edge is generated. The normal value is set to “n”, and the counter value of the electrical angle counter is the reverse of the motor both when the previous edge is generated from the electrical angle sensor and when the current edge is generated. Based on the indication of the change in the rotation direction, it is determined that the brushless motor is rotating in reverse, the normal value is set to “−n”, and the previous edge occurrence from the electrical angle sensor is set. The forward and reverse rotation of the brushless motor is being reversed based on the fact that the change in the counter value of the electrical angle counter differs between the change in the forward direction of the motor and the change in the reverse direction of the motor. The normal value is set to “0”, and the second correction means shows a change in which the counter value of the electrical angle counter is not normally possible in the motor forward rotation direction. When the second correction value is set to “n” and the counter value of the electric angle counter indicates a change that is not normally possible in the reverse rotation direction of the motor, the second correction value is set to “−n”. It was supposed to be set.

  When noise occurs in the signal from the electrical angle sensor and the noise overlaps the edge of the pulse signal from another electrical angle sensor, the counter value of the electrical counter is reversed from the motor rotation direction during the noise generation period. Changes in the direction and changes that are normally impossible in the same direction as the motor rotation direction.

  For example, if the counter value of the electrical angle counter changes in the direction opposite to the motor rotation direction as described above during normal rotation of the brushless motor, the normal value is originally set to “n” by the setting means. The place to be set is set to “0”. As a result, the deviation amount of the difference (Pi−Pi−1) from the normal value is “0” if it is originally “0”, and the first correction value is erroneously changed to “−” n ”is used to correct the counter value of the position counter. For this reason, the counter value of the position counter is erroneously corrected by the first correction value. However, if the counter value of the electrical angle counter shows a change that cannot normally occur in the same direction as the motor rotation direction (positive rotation direction), the second correction value is set to “n” and the counter value of the position counter is corrected. Used for. Thereby, the erroneous correction of the counter value of the position counter by the first correction value can be appropriately invalidated.

  If the counter value of the electrical angle counter changes in the direction opposite to the motor rotation direction as described above during reverse rotation of the brushless motor, the normal value is originally set to “−n” by the setting means. The place to be set is set to “0”. As a result, the deviation amount of the difference (Pi−Pi−1) from the normal value is “0” if it is originally “0”. Correspondingly, the first correction value is erroneously “n”. In this state, it is used for correcting the counter value of the position counter. For this reason, the counter value P of the position counter is erroneously corrected by the first correction value. However, if the counter value of the electrical angle counter shows a change that cannot normally occur in the same direction as the motor rotation direction (reverse rotation direction), the second correction value is set to “−n” and the counter value of the position counter Used for correction. Thereby, the erroneous correction of the counter value of the position counter by the first correction value can be accurately invalidated.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the electrical angle counter is “0” to “m” according to the output pattern of the pulse signal from each electrical angle sensor when the brushless motor is rotating forward. Each successive integer value in the range of? Is applied as a counter value in the forward direction, and during reverse rotation of the brushless motor, a range of "0" to "m" in accordance with the output pattern of the pulse signal from each electrical angle sensor Each successive integer value is applied as a counter value in the reverse direction, and the second correction unit is configured to change the counter value based on the fact that the counter value of the electrical angle counter is changed by skipping the integer value in the forward direction. Based on the fact that the counter value of the electrical angle counter changed by skipping an integer value in the reverse direction, it was determined that the value showed a change that would normally not be possible in the forward rotation direction of the motor. It was assumed that the counter value is determined to show changes improbable usually for motor reverse rotation direction.

  In this case, during the forward rotation of the brushless motor, the counter value of the electrical angle counter that is normally impossible in the forward rotation direction due to the occurrence of noise in the electrical angle sensor signal is the forward direction (forward rotation) The direction is changed by skipping an integer value by one. In addition, during the reverse rotation of the brushless motor, the counter value of the electrical angle counter, which is normally impossible in the reverse rotation direction due to the occurrence of noise in the electrical angle sensor signal, ) Is changed in such a manner that the integer value is changed by one.

  According to the above configuration, based on the fact that the counter value of the electrical angle counter has changed by skipping an integer value in the forward direction, it is determined that the counter value has shown a change that is not normally possible in the motor forward rotation direction. The correction value of 2 is set to “−n”. Further, based on the fact that the counter value of the electrical angle counter has changed in the reverse direction by skipping an integer value, it is determined that the counter value has shown a change that is not normally possible in the motor reverse rotation direction, and the second correction value is Set to “n”. As described above, when the second correction value is set to either “−n” or “n”, it can be appropriately performed.

  According to a fifth aspect of the invention, in the invention according to any one of the first to fourth aspects, the brushless motor is used for driving a variable valve lift mechanism that varies a valve characteristic of an engine valve of an internal combustion engine. It was supposed to be.

  When a brushless motor is used for driving a variable valve lift mechanism of an internal combustion engine, the rotation angle of the brushless motor is detected based on the counter value of the position counter, and the rotation angle corresponds to the target valve characteristic. The motor is driven. As a result, the variable valve lift mechanism is driven and controlled so that the valve characteristic of the engine valve becomes the target valve characteristic. However, due to the occurrence of noise in the signal from the electrical angle sensor, the counter value of the position counter is erroneously corrected by the first correction value, and the counter value becomes the actual rotation angle of the brushless motor. Deviation from the corresponding value. As a result, the rotation angle of the brushless motor detected based on the counter value of the position counter becomes inaccurate, and even if it tries to drive and control the variable valve lift mechanism by driving the brushless motor based on the rotation angle, it can be done correctly. It will be lost and will have a negative effect on engine operation. According to the above configuration, the post-correction of the counter value of the position counter for the first correction value can be invalidated, and the counter value can be prevented from deviating from the value corresponding to the actual rotation angle of the brushless motor. Therefore, when the brushless motor is driven based on the rotation angle of the brushless motor detected based on the counter value of the position counter and the valve lift variable mechanism is to be driven and controlled, this cannot be performed correctly, leading to an adverse effect on engine operation. That's not true.

Hereinafter, an embodiment in which the present invention is applied to an automobile engine will be described with reference to FIGS.
FIG. 1 is an enlarged sectional view showing a structure around a cylinder head 2 of a predetermined cylinder in the engine 1. In the engine 1, a combustion chamber 6 is defined by a cylinder head 2, a cylinder block 3, and a piston 5, and an intake passage 7 and an exhaust passage 8 are connected to the combustion chamber 6. The intake passage 7 and the combustion chamber 6 are communicated and blocked by the opening / closing operation of the intake valve 9, and the exhaust passage 8 and the combustion chamber 6 are communicated and blocked by the opening / closing operation of the exhaust valve 10. Become.

  The cylinder head 2 is provided with an intake camshaft 11 and an exhaust camshaft 12 for driving the intake valve 9 and the exhaust valve 10. The intake camshaft 11 and the exhaust camshaft 12 are rotated by transmission of rotation from the crankshaft of the engine 1. The intake camshaft 11 and the exhaust camshaft 12 are provided with an intake cam 11a and an exhaust cam 12a, respectively. The intake valve 9 and the exhaust valve 10 are opened and closed through integral rotation of the intake cam shaft 11 and the exhaust cam shaft 12 of the intake cam 11a and the exhaust cam 12a.

  Further, the engine 1 is a valve lift variable mechanism that varies the valve characteristics of the engine valves such as the intake valve 9 and the exhaust valve 10, and the valve lift that varies the maximum lift amount of the intake valve 9 and the operating angle of the intake cam 11a. A variable mechanism 14 is provided between the intake cam 11 a and the intake valve 9. Through the driving of the variable valve lift mechanism 14, for example, the maximum lift amount and the operating angle are controlled to increase as the engine operation state that requires a larger intake air amount is reached. This is because the larger the maximum lift amount and the operating angle, the more efficiently the air is sucked into the combustion chamber 6 from the intake passage 7 and the above-described requirements regarding the intake air amount can be satisfied.

Next, the detailed structure of the variable valve lift mechanism 14 will be described.
The variable valve lift mechanism 14 includes an input arm 17 that is pushed by the rotating intake cam 11 a and swings about the axes of the rocker shaft 15 and the control shaft 16 extending in parallel with the intake cam shaft 11, and the input arm 17 And an output arm 18 that swings about the axis based on the swing. The input arm 17 is rotatably attached to a roller 19 and is biased toward the intake cam 11a by a coil spring 20 so that the roller 19 is pressed against the intake cam 11a. Further, the output arm 18 is pressed against the rocker arm 21 when swinging, and lifts the intake valve 9 via the rocker arm 21.

  The base end portion of the rocker arm 21 is supported by a lash adjuster 22, and the distal end portion of the rocker arm 21 is in contact with the intake valve 9. The rocker arm 21 is urged toward the output arm 18 by the valve spring 24 of the intake valve 9, whereby a roller 23 rotatably supported between the base end portion and the distal end portion of the rocker arm 21 is applied to the output arm 18. It is pressed. Therefore, when the input arm 17 and the output arm 18 swing based on the rotation of the intake cam 11a, the output arm 18 lifts the intake valve 9 via the rocker arm 21, and the intake valve 9 is opened and closed.

  In the variable valve lift mechanism 14, the relative position of the input arm 17 and the output arm 18 in the swinging direction is changed by displacing the control shaft 16 disposed in the pipe-shaped rocker shaft 15 in the axial direction. Is possible. Thus, when the relative position of the input arm 17 and the output arm 18 in the swing direction is changed, the maximum lift amount of the intake valve 9 and the operating angle of the intake cam 11a with respect to the intake valve 9 are made variable. That is, as the input arm 17 and the output arm 18 are brought closer to each other in the swing direction, the maximum lift amount of the intake valve 9 and the operating angle of the intake cam 11a become smaller. Conversely, as the input arm 17 and the output arm 18 are separated from each other in the swinging direction, the maximum lift amount of the intake valve 9 and the operating angle of the intake cam 11a increase.

  Next, a drive mechanism for displacing the control shaft 16 in the axial direction to drive the variable valve lift mechanism 14 and a control device for driving and controlling the drive mechanism will be described with reference to FIG.

  As shown in the figure, a brushless motor 47 is connected to a base end portion (right end portion in the figure) of the control shaft 16 via a conversion mechanism 48. The conversion mechanism 48 is for converting the rotational motion of the brushless motor 47 into linear motion in the axial direction of the control shaft 16. Then, the rotation of the brushless motor 47 within a predetermined rotation angle range, for example, the rotation of the motor 47 within a rotation angle range (0 to 3600 °) corresponding to 10 rotations causes the control shaft 16 to move in the axial direction. As a result, the variable valve lift mechanism 14 is driven.

  Incidentally, when the brushless motor 47 is rotated forward, the control shaft 16 is displaced toward the tip (left end in the figure), and the relative positions of the input arm 17 and the output arm 18 in the swing direction are changed so as to approach each other. The Further, when the brushless motor 47 is rotated in the reverse direction, the control shaft 16 is displaced toward the base end (right end in the figure), and the relative positions of the input arm 17 and the output arm 18 in the swing direction are changed from each other. Is done. The maximum lift amount of the intake valve 9 when the output arm 18 swings due to the rotation of the intake cam 11a through the change of the relative position in the swing direction of the input arm 17 and the output arm 18 by the rotational drive of the brushless motor 47, The operating angle of the intake cam 11a is variable.

The brushless motor 47 is provided with three electrical angle sensors S1 to S3 and two position sensors S4 and S5.
The three electrical angle sensors S1 to S3 are shown in FIGS. 3A to 3C according to the magnetism of the four-pole multipolar magnet that rotates integrally with the rotor of the motor 47 when the brushless motor 47 rotates. Such a pulse signal, that is, a high signal “H” and a low signal “L” are alternately output. In addition, the pulse signals from the electrical angle sensors S1 to S3 are output with their phases shifted from each other. That is, the circumferential positions of the electric angle sensors S1 to S3 with respect to the rotor are determined so that the waveform of the pulse signal can be obtained. Note that the edge of the pulse signal output from one of the electrical angle sensors S <b> 1 to S <b> 3 is generated every 45 ° rotation of the brushless motor 47. Further, the pulse signal from the one sensor is in a state where the phase is shifted to the advance side and the delay side by 30 ° rotation of the brushless motor 47 with respect to the pulse signal from the other sensor.

  As shown in FIGS. 3D and 3E, the two position sensors S4 and S5 correspond to the magnetism of the 48-pole multipole magnet that rotates integrally with the rotor of the motor 47 when the brushless motor 47 rotates. , A high signal “H” and a low signal “L” are alternately output. The pulse signals from the position sensors S4 and S5 are output in a state where the phases are shifted from each other. That is, the circumferential positions of the position sensors S4 and S5 with respect to the rotor are determined so that the waveform of the pulse signal can be obtained. The edge of the pulse signal output from one of the position sensors S4 and S5 is generated every 7.5 ° rotation of the brushless motor 47. Further, the pulse signal from the one sensor is in a state of being shifted in phase by the amount of 3.75 ° rotation of the brushless motor 47 with respect to the pulse signal from the other sensor.

  Therefore, while the edge interval of the pulse signals from the electrical angle sensors S1 to S3 is 15 °, the edge interval of the pulse signals from the position sensors S4 and S5 is 3.75 °, which is larger than the edge interval of 15 °. It is getting shorter. Further, the edge of the pulse signal from the position sensors S4 and S5 is generated four times from the generation of the edge of the pulse signal from the electrical angle sensors S1 to S3 to the next generation of the edge.

  The control device of the brushless motor 47 that is rotationally driven to displace the control shaft 16 in the axial direction includes control of the valve characteristics of the intake valve 9 such as the maximum lift amount of the intake valve 9 and the operating angle of the intake cam 11a. An electronic control device 50 (FIG. 2) that performs various controls is provided. The electronic control unit 50 includes a CPU that executes arithmetic processing related to the above various controls, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores arithmetic results of the CPU, and an external interface. The input / output port for inputting / outputting the signal is provided.

In addition to the electrical angle sensors S1 to S3 and the position sensors S4 and S5 described above, various sensors including the following sensors are connected to the input port of the electronic control unit 50.
An accelerator position sensor 51 that detects the amount of depression of the accelerator pedal (accelerator depression amount) that is depressed by the driver of the automobile.

A throttle position sensor 52 that detects the opening (throttle opening) of a throttle valve provided in the intake passage 7 of the engine 1.
An air flow meter 53 for detecting the amount of air taken into the combustion chamber 6 through the intake passage 7;

A crank position sensor 54 that outputs a signal corresponding to the rotation of the output shaft of the engine 1 and is used for detecting the engine rotation speed and the like.
An ignition switch 55 that is switched by an automobile driver and outputs a signal corresponding to the current switching position.

  The output port of the electronic control device 50 is connected to a drive circuit for the brushless motor 47 and the like. The electronic control unit 50 grasps the engine operating state based on the detection signals input from the various sensors. Then, the brushless motor 47 is driven based on the grasped engine operating state to displace the control shaft 16 in the axial direction, whereby the variable valve lift mechanism 14 is driven and the valve characteristics of the intake valve 9 are controlled. The brushless motor 47 is driven by switching the energized phase of the brushless motor 47 in accordance with the output pattern of the pulse signal output from the electric angle sensors S1 to S3 when the motor 47 rotates.

  The valve characteristics of the intake valve 9, that is, the maximum lift amount of the intake valve 9 and the operating angle of the intake cam 11 a correspond to the axial position of the control shaft 16, in other words, the rotation angle of the brushless motor 47 within the predetermined rotation angle range. Will be. Therefore, in order to precisely control the valve characteristic of the intake valve 9, the rotation angle of the brushless motor 47 is accurately detected, and the brushless motor 47 is driven so that the rotation angle becomes a rotation angle corresponding to the target valve characteristic. It becomes important to do.

Hereinafter, the detection procedure of the rotation angle of the brushless motor 47 in this embodiment will be described with reference to the timing chart of FIG. 3 and the flowchart of FIG.
3A to 3E are waveform diagrams showing how pulse signals are output from the sensors S1 to S5 in response to the rotation angle change of the motor 47 when the brushless motor 47 rotates. It is. Further, in (f) to (h), how the counter values of the electric angle counter E, the position counter P, and the stroke counter S correspond to changes in the rotation angle of the motor 47 when the brushless motor 47 rotates. It shows whether it will change.

  The electrical angle counter E is used when the energized phase of the motor 47 is switched to drive the brushless motor 47. Further, the position counter P indicates how much the control shaft 16 is displaced in the axial direction after the ignition switch 55 is turned on (ignition on) when starting the operation of the engine 1, in other words, the rotational angle of the brushless motor 47 is It shows how much has changed. Further, the stroke counter S is an axial position based on a state where the control shaft 16 is displaced to the most distal side, in other words, an end corresponding to the displacement state of the control shaft 16 in the predetermined rotation angle range of the brushless motor 47. Represents the rotation angle of the motor 47 with reference to.

  FIG. 4 is a flowchart showing a count processing routine for changing the counter values of the electrical angle counter E, the position counter P, and the stroke counter S. The routine is periodically executed through the electronic control unit 50 at intervals shorter than the time intervals corresponding to the edge intervals of the pulse signals from the position sensors S4 and S5.

  In this routine, first, based on the output patterns of the pulse signals from the electric angle sensors S1 to S3 shown in FIGS. 3A to 3C, the electric angle counter E is set as shown in FIG. The counter value is changed (S101).

  More specifically, as shown in FIG. 5 (a), an electrical angle counter is selected depending on whether a high signal “H” or a low signal “L” is output from each of the electrical angle sensors S1 to S3. One of consecutive integer values in the range where the counter value of E is in the range of “0” to “5” is applied. As a result, during the forward rotation of the brushless motor 47 (rightward in FIG. 3), “0” to “m (5 in this embodiment)” according to the output pattern of the pulse signals from the electrical angle sensors S1 to S3. Each successive integer value within the range of “0” → “1” → “2” → “3” → “4” → “5” → “0” in the forward direction is the counter value of the electrical angle counter E As applied. Further, when the brushless motor 47 rotates in the reverse direction (leftward in FIG. 3), it continues within the range of “0” to “m (5)” according to the pulse signal output pattern from the electrical angle sensors S1 to S3. These integer values are applied as counter values of the electrical angle counter E in the reverse direction in the order of “5” → “4” → “3” → “2” → “1” → “0” → “5”. For some reason, all the electrical angle sensors S1 to S3 output a high signal “H”, or all the electrical angle sensors S1 to S3 may output a low signal “L”. In this case, it is determined that the state is abnormal, and the counter value of the electrical angle counter E is held as it is.

Then, by switching the energization layer of the brushless motor 47 based on the counter value of the electric angle counter E, the motor is driven in the forward rotation direction or the reverse rotation direction.
Subsequently, the counter value of the position counter P is increased or decreased based on the pulse signal output patterns from the position sensors S4 and S5 (S102 in FIG. 4).

  Specifically, as shown in FIG. 5 (b), one of the position sensors S4 and S5 has a rising edge or a falling edge of the pulse signal, and the other sensor is high. Depending on whether the signal “H” or the low signal “L” is output, either “+1” or “−1” is added to the counter value of the position counter P. In the figure, “↑” represents the rising edge of the pulse signal, and “↓” represents the falling edge of the pulse signal. The counter value of the position counter P obtained through such processing is a value obtained by counting the edges of the pulse signals from the position sensors S4 and S5.

  Here, if the brushless motor 47 is rotating forward, the counter value of the position counter P is “1” for each edge of the pulse signal from the position sensors S4 and S5 shown in FIGS. The values are added one by one and change to the right in FIG. If the brushless motor 47 is rotating in reverse, the counter value of the position counter P is decremented by “1” for each edge, and changes to the left in FIG. The position counter P is reset to “0” when the ignition switch 55 is turned off (ignition off). Therefore, the counter value of the position counter P represents how much the control shaft 16 is displaced in the axial direction after the ignition is turned on.

  Then, the stroke counter S is changed as shown in FIG. 3 (h) in accordance with the position counter P changing as shown in FIG. 3 (g). Specifically, a value obtained by adding a value (−Pr) obtained by inverting the sign of the learning value Pr to the position counter P is set as a counter value of the stroke counter S (S103 in FIG. 4). Note that the learning value Pr is the value obtained when the control shaft 16 is displaced to the displacement end on the left end (tip) side in FIG. 2 in the movement range, that is, the rotation angle of the brushless motor 47 is within the predetermined rotation angle range. This is a value corresponding to the counter value of the position counter P when it is changed to the end corresponding to the displacement state of the control shaft 16. This learning value Pr is learned under a predetermined condition after the ignition is turned on, and is stored in the nonvolatile memory 56 of the electronic control unit 50. Therefore, the counter value of the stroke counter S, which is a value obtained by adding a value obtained by inverting the sign of the learning value Pr to the counter value of the position counter P, is based on the state of displacement of the control shaft 16 to the most distal end side. This represents the axial position of the shaft 16. In other words, the counter value of the stroke counter S represents the rotation angle of the motor 47 with respect to the end corresponding to the displacement state of the control shaft 16 in the predetermined rotation angle range of the brushless motor 47. That's what it means.

  The electronic control unit 50 detects the rotation angle of the brushless motor 47 based on the counter value of the stroke counter S. When the electronic control unit 50 controls the valve characteristics such as the maximum lift amount of the intake valve 9 and the operating angle of the intake cam 11a by driving the variable valve lift mechanism 14, the electronic control unit 50 detects the brushless motor 47 detected as described above. The brushless motor 47 is driven so that the rotation angle becomes a rotation angle corresponding to the target valve characteristic. As a result, the valve characteristic of the intake valve 9 can be precisely controlled to a target characteristic.

  Note that, instead of counting the edges of the pulse signals from the position sensors S4 and S5 during the rotation of the brushless motor 47 as described above, even if the edges of the pulse signals from the electrical angle sensors S1 to S3 are counted, the counted value The rotation angle of the brushless motor 47 can be roughly detected based on the above. However, when high accuracy is required for detection of the rotation angle of the motor 47, such as detection of the rotation angle of the brushless motor 47 for driving the variable valve lift mechanism 14, the above-mentioned Rough rotation angle detection results in insufficient detection accuracy. For this reason, position sensors S4 and S5 that output pulse signals at edge intervals shorter than the edge intervals of the pulse signals from the electrical angle sensors S1 to S3 are provided, and the edges of the pulse signals from the position sensors S4 and S5 are counted. The rotation angle of the brushless motor 47 is detected based on the counter value of the position counter P.

  By the way, the counter value of the position counter P does not always correspond to the actual rotation angle of the brushless motor 47, and may deviate from the value corresponding to the actual rotation angle. For example, when noise is generated in the signals output from the position sensors S4 and S5, the noise edge cannot be distinguished from the edge of the pulse signal from the position sensors S4 and S5. And the counter value of the position counter P that counts the edges of the pulse signal does not correspond to the actual rotation angle of the brushless motor 47.

  Hereinafter, details of the occurrence of the problem will be described with reference to FIG. 6 by taking, as an example, the case where the noise occurs during the forward rotation of the motor and the case where the noise occurs during the reverse rotation of the motor. 6A to 6E show the waveforms of the pulse signals from the position sensors S4 and S5 with respect to the change in the rotation angle of the brushless motor 47, the transition of the counter value of the electric angle counter E, and the position counter. It shows the transition of the counter value of P.

  During forward rotation of the brushless motor 47, for example, as shown in FIG. 6A, noise occurs in the signal from the position sensor S4, and the noise overlaps with the falling edge of the pulse signal from the position sensor S5. An output pattern of signals from the position sensors S4 and S5 at the timings a, b, and c where the noise is generated is a pattern as shown in FIG. As a result, “−1” is added to the counter value of the position counter P at each of the timings a, b, and c. At the timings a, b, and c in FIG. Decrease by 1 ”. On the other hand, if the noise is not generated, at timings a, b, and c, “1” should only be added to the counter value of the position counter P at timing b. Therefore, the counter value of the position counter P when the noise is generated is “4” as indicated by a two-dot chain line with respect to a value (solid line) corresponding to the actual rotation angle of the brushless motor 47 after the timing c. "Is smaller.

  During the reverse rotation of the brushless motor 47, for example, noise shown in FIG. 6A is generated, and the counter value of the position counter P is also brushless even when the noise overlaps the rising edge of the pulse signal from the position sensor S5. It will deviate from the value corresponding to the actual rotation angle of the motor 47. That is, the output pattern of signals from the position sensors S4, S5 at the timings c, b, a where the noise is generated becomes a pattern as shown in FIG. 7B, and at the timings c, b, a, respectively. “1” is added to the counter value of the position counter P, and the counter value is incremented by “1” at the timings c, b, and a in FIG. On the other hand, if the noise is not generated, “−1” should be added to the counter value of the position counter P at timing b at timings c, b, and a. Therefore, the counter value of the position counter P when the noise is generated is “4” as indicated by a two-dot chain line with respect to a value (solid line) corresponding to the actual rotation angle of the brushless motor 47 after the timing a. "Will only increase.

  As described above, when noise is generated in the signals output from the position sensors S4 and S5, and the noise overlaps with the edge of the pulse signal from the position sensors S4 and S5, the counter value of the position counter P becomes the value of the brushless motor 47. It will not correspond to the actual rotation angle. As a result, the actual rotation angle of the brushless motor 47 detected based on the counter value of the position counter P (more precisely, the stroke counter S) becomes inaccurate, and the brushless motor 47 is driven based on the rotation angle and the like, Even if it is attempted to control the valve characteristic of the valve 9 to the target characteristic, it cannot be performed correctly, leading to an adverse effect on engine operation. More specifically, since the valve characteristic of the intake valve 9 cannot be controlled to a target characteristic, the intake air amount of the engine 1 cannot be correctly estimated based on the valve characteristic. As a result, the engine 1 is controlled based on the estimated intake air amount. When the operation control is performed, an emission failure or an acceleration failure of the engine 1 is caused.

  In order to suppress the occurrence of the problems due to the noise described above, a deviation amount from the value corresponding to the actual rotation angle of the brushless motor 47 in the counter value of the position counter P is obtained, and the amount corresponding to the deviation amount is obtained. It is necessary to add correction to the counter value and return the counter value to a value corresponding to the actual rotation angle of the brushless motor 47. For this reason, as described in the section “Problems to be Solved by the Invention”, a linear sensor or the like for detecting the actual rotation angle of the brushless motor 47 is separately provided, and the rotation angle detected by the sensor is the position counter P. When the rotation angle detected based on the counter value or the like does not correspond, the counter value may be corrected by the correction value obtained based on the difference between the two. However, in this case, it takes time to install a linear sensor or the like, and a new problem arises that the mounting position of the brushless motor 47 is restricted in relation to the installation of the sensor. Is as described in the column “Problems”.

  Therefore, in the present embodiment, the pulse signal from the electric angle sensors S1 to S3 used for driving the brushless motor 47 is used to obtain a value from the value corresponding to the actual rotation angle of the brushless motor 47 in the counter value of the position counter P. A deviation amount is obtained, and a correction corresponding to the deviation amount is added to the counter value. More specifically, the counter value of the position counter P described above is corrected by executing the following processes [1] to [3], and the counter value is a value corresponding to the actual rotation angle of the brushless motor 47. I try to return to

  [1] Every time an edge of the pulse signal output from each of the electrical angle sensors S1 to S3 occurs, the counter value Pi of the position counter P when the current edge is generated and the counter value Pi− of the position counter P when the previous edge is generated The difference (Pi-Pi-1) from 1 is calculated.

  [2] Based on the change in the counter value of the electrical angle counter E, it is determined whether the rotation state of the brushless motor 47 is normal rotation, reverse rotation, or normal / reverse rotation inversion, and the brushless motor 47 The normal value J, which is the normal value of the difference (Pi-Pi-1), is variably set in accordance with the rotation state of. This variable setting of the normal value J is related to the number of edges n of the pulse signals output from the position sensors S4 and S5 between the edges of the pulse signals from the electrical angle sensors S1 to S3 (“4” in this embodiment). Thus, if the normal value J is in the forward rotation of the motor, it is “n”, if it is in the reverse rotation of the motor, it is “−n”, and if it is in the reverse rotation of the motor, it is “0”.

  [3] A deviation “J− (Pi−Pi−1)” of the difference (Pi−Pi−1) with respect to the normal value J is set as a first correction value ΔP, and correction for the first correction value ΔP is performed. It adds to the counter value of the position counter P.

  In this case, when the counter value of the position counter P does not correspond to the actual rotation angle of the brushless motor 47 due to the generation of the noise and is shifted from the value corresponding to the actual rotation angle, the difference ( The deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle is reflected in Pi-Pi-1). That is, the difference (Pi-Pi-1) deviates from the normal value J by the amount of deviation. Therefore, by adding the correction for the first correction value ΔP calculated in the process [3] to the counter value of the position counter P, from the value corresponding to the actual rotation angle of the brushless motor 47 at the counter value. The deviation can be eliminated. Therefore, when the brushless motor 47 is driven based on the rotation angle of the brushless motor 47 detected based on the counter value of the position counter P (more precisely, the stroke counter S), and the valve lift variable mechanism 14 is to be driven and controlled, It will not be able to do it correctly and will not adversely affect engine operation. Further, in order to calculate the difference (Pi−Pi−1) for obtaining the first correction value ΔP, it suffices if there are electrical angle sensors S1 to S3 used for driving the brushless motor 47, and the occurrence of the abnormality is described. There is no need to provide a new sensor or the like for detection.

Next, determination of the rotation state of the brushless motor 47 in the process [2] will be described with reference to FIGS.
8A to 8E show pulse signals from the electrical angle sensors S1 to S3 when the rotation state of the brushless motor 47 changes during forward rotation, forward / reverse rotation inversion, and reverse rotation. , The counter value of the electrical angle counter E, and how the motor status changes.

  The motor status shown in FIG. 8 (e) depends on the change of the electric angle counter E so that it represents the rotational direction of the brushless motor 47 every time the edge of the pulse signal from the electric angle sensors S1 to S3 is generated. Is set.

  Specifically, when the edge is generated, the counter value of the electrical angle counter E is forward (motor forward rotation direction), that is, “0” → “1” → “2” → “3” → “4” → “5” → “ When the value changes by one integer value in the direction of “0”, the motor status is set to “cw”. When the edge is generated, the counter value of the electrical angle counter E is in the reverse direction (motor reverse rotation direction), that is, “5” → “4” → “3” → “2” → “1” → “0” → “5 In the direction of “”, the motor status is set to “ccw”. When the edge is generated, if the counter value of the electrical angle counter E does not change for some reason, the motor status is set to “hold”.

  Whether the rotation state of the brushless motor 47 is normal rotation, reverse rotation, or normal / reverse rotation reversal is determined when the previous edge of the pulse signal from the electrical angle sensors S1 to S3 is generated and the current edge. Judgment is made based on each motor status at the time of occurrence.

  That is, as shown in FIG. 9, if both the motor statuses at the time of the previous edge generation and the current edge generation are “cw”, both the brush generation motor at the time of the previous edge generation and the current edge generation are both. 47 is rotating forward, and as a result, it is determined that the motor is rotating forward. Also, if the motor status at the time of the previous edge occurrence and the current edge occurrence is both “ccw”, the brushless motor 47 is rotating in the reverse direction at both the previous edge occurrence and the current edge occurrence. As a result, it is determined that the motor is rotating in reverse. Further, if the motor status is different between “cw” and “ccw” when the previous edge is generated and when the current edge is generated, the rotation of the brushless motor 47 is performed when the previous edge is generated and when the current edge is generated. As a result, it is determined that the motor is rotating in the reverse direction.

  If the motor status at the time of the current edge generation is “hold”, the determination of the rotation state of the brushless motor 47 is not performed. Also, the “hold” is not used as the previous motor status when the next edge occurs, and the motor status at the time of the previous edge generation when the edge where the motor status becomes “hold” is the previous motor status. Will be used.

  Next, an outline of correction of the counter value of the position counter P by the above-described first correction value ΔP will be described with reference to FIG. 6 taking the above correction during forward rotation and reverse rotation of the brushless motor 47 as an example. To do.

  If noise occurs as shown in FIG. 6A during the forward rotation of the brushless motor 47, the counter value of the position counter P becomes the actual rotation angle of the brushless motor 47 as shown in FIG. 6D. As described above, the corresponding value (solid line) is reduced by “4” as indicated by the two-dot chain line. In this case, when the edge of the pulse signal from the electrical angle sensors S1 to S3 in which the counter value of the electrical angle counter E changes from “2” to “3”, the difference (Pi−Pi−1) is the normal value J ( = 4) becomes “0” shifted by “−4”.

  When the edge of the pulse signal from the electrical angle sensors S1 to S3 in which the counter value of the electrical angle counter E changes from “2” to “3” is generated, the difference (Pi−Pi−1) with respect to the normal value J (= 4). ) Is set to the first correction value ΔP, and the correction for the first correction value ΔP is added to the counter value (two-dot chain line) of the position counter P. It is done. As a result, as indicated by a black arrow in FIG. 6E, the counter value of the position counter P changes to a value (solid line) corresponding to the actual rotation angle of the brushless motor 47. As a result, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle (solid line) is corrected.

  If noise occurs as shown in FIG. 6A during the reverse rotation of the brushless motor 47, the counter value of the position counter P becomes the actual rotation angle of the brushless motor 47 as shown in FIG. As described above, the corresponding value (solid line) is increased by “4” as indicated by the two-dot chain line. In this case, when the edge of the pulse signal from the electrical angle sensors S1 to S3 in which the counter value of the electrical angle counter E changes from “3” to “2” is generated, the difference (Pi−Pi−1) is a normal value J ( -4) is shifted to “0” by “4”.

  When the edge of the pulse signal from the electrical angle sensors S1 to S3 in which the counter value of the electrical angle counter E changes from “2” to “1” is generated, the difference (Pi−Pi−) with respect to the normal value J (= −4). 1) The deviation “J− (Pi−Pi−1) = − 4” is the first correction value ΔP, and the correction for the first correction value ΔP is the counter value of the position counter P (two-dot chain line). Added to. As a result, as indicated by a black arrow in FIG. 6D, the counter value of the position counter P changes to a value (solid line) corresponding to the actual rotation angle of the brushless motor 47. As a result, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle (solid line) is corrected.

  Next, a correction procedure for returning the counter value to the correct value when the counter value of the position counter P deviates from the correct value will be described with reference to the flowchart of FIG. 10 showing the position counter correction routine. This position counter correction routine is periodically executed through the electronic control unit 50 at intervals shorter than the time intervals corresponding to the edge intervals of the pulse signals from the position sensors S4 and S5.

  In this routine, first, the processes of steps S201 to S203 are executed as the process of [1]. That is, when an edge of the pulse signal from the electrical angle sensors S1 to S3 occurs (S201: YES), the counter value of the position counter P is stored in the memory of the electronic control unit 50 (S202), and the current edge generation time is generated. A difference (Pi-Pi-1) between the counter value Pi and the counter value Pi-1 at the previous edge occurrence is calculated (S203).

  Subsequently, the processes of steps S204 to S208 are executed as the process [2]. That is, the rotational state of the brushless motor 47 is determined based on the motor status between the previous edge generation and the current edge generation in the pulse signals from the electrical angle sensors S1 to S3, and the difference (Pi − The normal value J of Pi-1) is variably set. Specifically, the normal value J is set to “4” if the motor is rotating forward (S204: YES) (S206), and is set to “−4” if the motor is rotating backward (S205: YES). If the motor is rotating in the forward / reverse rotation direction (NO in both S204 and S205), it is set to “0” (S208). If the motor status at the time of the occurrence of the current edge is “hold” and the rotation state of the brushless motor 47 is not determined, a negative determination is made in steps S204 and S205, and the normal value J is set to the step. It is set to “0” in the process of S208.

  Thereafter, as the process [3], the processes of steps S209 and S210 are executed. That is, the deviation “J− (Pi−Pi−1)” of the difference (Pi−Pi−1) with respect to the normal value J is set as the first correction value ΔP (S209). Then, the correction for the first correction value ΔP is added to the counter value of the position counter P (S210). As a result, even if the counter value of the position counter P deviates from a value corresponding to the actual rotation angle of the brushless motor 47, the deviation is corrected.

  Incidentally, noise may occur in signals from the electrical angle sensors S1 to S3. In this case, the noise is mistaken as a pulse signal from the electrical angle sensors S1 to S3, and the counter value of the electrical angle counter E may change to an incorrect value. When the counter value of the electrical angle counter E changes to an incorrect value, the rotation state of the brushless motor 47 determined based on the counter value is different from the actual state, and is set according to the motor rotation state. Normal value J does not correspond to the actual motor rotation state. Under such circumstances, the deviation “J− (Pi−Pi−1)” of the difference (Pi−Pi−1) with respect to the normal value J due to the abnormality of the normal value J described above is the first. The correction value ΔP of 1 is an incorrect value. When the correction for the first correction value ΔP is added to the counter value of the position counter P, the counter value deviates from a value corresponding to the actual rotation angle of the brushless motor 47. As a result, the rotation angle of the brushless motor 47 detected based on the counter value of the position counter P becomes an incorrect value.

  Next, the details of the occurrence of the problem will be described with reference to FIG. 11, taking as an example the case where the noise occurs during the forward rotation of the motor and the case where the noise occurs during the reverse rotation of the motor. In FIG. 11, (a) to (i) are waveforms of pulse signals from the electrical angle sensors S1 to S3 with respect to changes in the rotation angle of the brushless motor 47, waveforms of pulse signals from the position sensors S4 and S5, and electricity. It shows the transition of the counter value of the angle counter E and the transition of the counter value of the position counter P.

[During motor forward rotation]
During the forward rotation of the brushless motor 47, for example, as indicated by a broken line L1 in FIG. 11B, noise is generated in the signal from the electrical angle sensor S2, and the noise is the rising edge of the pulse signal from the electrical angle sensor S1. , The output patterns of signals from the electrical angle sensors S1 to S3 at the timings a, b, and c where the noise is generated are different from those at normal times. The counter value of the electrical angle counter E changes to an incorrect value as indicated by a broken line L2 in FIG.

  Here, the output pattern of the signals from the electrical angle sensors S1 to S3 at the timings a, b, and c, the counter value of the electrical angle counter E, the previous edge generation in the signals from the electrical angle sensors S1 to S3, and the current time FIG. 12A shows the motor status, normal value J, difference (Pi−Pi−1), and first correction value ΔP (= “J− (Pi−Pi−1)”) from the time of edge generation. Shown in

  Timing a corresponds to the rising edge of the noise. Therefore, at timing a, due to the rising edge of the noise, the signals from the electrical angle sensors S1 to S3 are “L”, “H”, and “H”, respectively, and the counter value of the electrical angle counter E is “ It changes from “2” to “1”. Therefore, the motor status at the time of the previous edge occurrence and the motor status at the occurrence of the current edge in the signals from the electrical angle sensors S1 to S3 are “cw” and “ccw”, respectively. As a result, an erroneous determination that the motor is rotating in the forward / reverse rotation is made, and the normal value J is erroneously set to “0”. In this case, the difference (Pi−Pi−1) between the counter value Pi of the position counter P when the current edge occurs and the counter value Pi−1 of the position counter P when the edge occurs is “4”. The first correction value ΔP (= “J− (Pi−Pi−1)”), which is the deviation of the difference (Pi−Pi−1) from the normal value J, is set to “−4”. Since the correction for the first correction value ΔP is added to the counter value of the position counter P, the counter value is erroneously set to “−4” as indicated by the black arrow Y1 in FIG. Will be made smaller.

  Timing b corresponds to the rising edge of the pulse signal from the electrical angle sensor S1. At this timing b, due to the generation of the noise, all the electrical angle sensors S1 to S3 become the high signal “H” as shown in FIG. The value “1” is held. As a result, the motor status when the current edge occurs in the signals from the electrical angle sensors S1 to S3 is “hold”, and the normal value J is set to “0”. Further, the difference (Pi−Pi−1), which is the change amount of the position counter P from the timing a to the timing b, is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “0”, and the correction for the first correction value ΔP is added to the counter value of the position counter P. There is no.

  Timing c corresponds to the falling edge of the noise. At this timing c, due to the falling edge of the noise, the signals from the electrical angle sensors S1 to S3 become “H”, “L”, and “H”, respectively, and the counter value of the electrical angle counter E is normal. An unobtainable change, that is, a change in which an integer value is skipped in the forward direction from “1” to “3”. The change of the counter value of the electrical angle counter E at the time of the occurrence of the current edge is regarded as a change in the forward direction, and the motor status at the occurrence of the current edge is set to “cw” as indicated by hatching in the figure. Then, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “ccw” and “cw”, respectively. As a result, the normal value J is set to “0”. Further, the difference (Pi−Pi−1) which is the change amount of the position counter P from the timing b to the timing c is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “0”, and the correction for the first correction value ΔP is added to the counter value of the position counter P. There is no.

  Accordingly, when the counter value of the electrical angle counter E changes as shown by the broken line L2 in FIG. 11 (f) due to the generation of noise shown by the broken line L1 in FIG. 11 (b), FIG. The correction for the first correction value ΔP (= −4) indicated by the black arrow Y1 is erroneously added to the counter value of the position counter P. As a result, the counter value of the position counter P deviates from a value (solid line) corresponding to the actual rotation angle of the brushless motor 47, as indicated by a broken line L3 in the drawing.

  Further, during the forward rotation of the brushless motor, for example, as indicated by a broken line L4 in FIG. 11B, noise is generated in the signal from the electrical angle sensor S2, and the noise is generated by the rise of the pulse signal from the electrical angle sensor S3. When overlapping with the falling edge, the output pattern of signals from the electrical angle sensors S1 to S3 at the timings d, e, and f at which the noise is generated becomes different from the normal time. The counter value of the electrical angle counter E changes to an incorrect value as indicated by a broken line L5 in FIG.

  Here, the output pattern of the signals from the electrical angle sensors S1 to S3 at the timings d, e, and f, the counter value of the electrical angle counter E, the time when the previous edge occurred in the signals from the electrical angle sensors S1 to S3, and the current time FIG. 12B shows the motor status, normal value J, difference (Pi−Pi−1), and first correction value ΔP (= “J− (Pi−Pi−1)”) from when the edge is generated. Shown in In the figure, after the timing f, the output pattern of the signals from the electrical angle sensors S1 to S3 at the timing g when the edges of the pulse signals from the electrical angle sensors S1 to S3 first occur, and the electrical angle counter E The counter value, the motor status between the occurrence of the previous edge and the current edge, the normal value J, the difference (Pi−Pi−1), and the first correction value ΔP are also shown.

  Timing d corresponds to the rising edge of the noise. For this reason, at the timing d, due to the rising edge of the noise, all the signals from the electrical angle sensors S1 to S3 become the high signal “H”, and the counter value of the electrical angle counter E is the value up to that time. 3 ". As a result, the motor status when the current edge occurs in the signals from the electrical angle sensors S1 to S3 is “hold”, and the normal value J is set to “0”. In this case, the difference (Pi−Pi−1) between the counter value Pi of the position counter P when the current edge occurs and the counter value Pi−1 of the position counter P when the edge occurs is “4”. The first correction value ΔP (= “J− (Pi−Pi−1)”), which is the deviation of the difference (Pi−Pi−1) from the normal value J, is set to “−4”. Then, since the correction for the first correction value ΔP is added to the counter value of the position counter P, the counter value is decreased by “−4” as indicated by the black arrow Y3 in FIG. Will be.

  The timing e corresponds to the falling edge of the pulse signal from the electrical angle sensor S3. At this timing e, due to the generation of the noise, the signals from the electrical angle sensors S1 to S3 become “H”, “H”, and “L”, respectively, as shown in FIG. The counter value of the counter E usually shows an impossible change, that is, a change in which the integer value is skipped by one in the forward direction from “3” to “5”. The change of the counter value of the electrical angle counter E at the time of occurrence of the current edge is regarded as a change in the forward direction, and the motor status at the time of occurrence of the current edge is set to “cw” as indicated by hatching in the figure. Then, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “cw” and “cw”, respectively. As a result, the normal value J is set to “4”. Further, the difference (Pi−Pi−1), which is the change amount of the position counter P from the timing d to the timing e, is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “4”, and correction for the first correction value ΔP is added to the counter value of the position counter P. The counter value is increased by “4” as indicated by the black arrow Y4 in FIG.

  Timing f corresponds to the falling edge of the noise. At this timing f, due to the falling edge of the noise, the signals from the electrical angle sensors S1 to S3 are “H”, “L”, and “L”, respectively, and the counter value of the electrical angle counter E is “5”. To "4". Therefore, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “cw” and “ccw”, respectively, and the normal value J is set to “0” based on the motor status. Further, the difference (Pi−Pi−1), which is the change amount of the position counter P from the timing e to the timing f, is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “0”, and the correction for the first correction value ΔP is added to the counter value of the position counter P. There is no.

  Timing g corresponds to the edge generation of the pulse signal from the first electrical angle sensors S1 to S3 after timing f. At this timing g, the signals from the electrical angle sensors S1 to S3 become “H”, “H”, and “L”, respectively, and the counter value of the electrical angle counter E changes from “4” to “5”. Therefore, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “ccw” and “cw”, respectively. As a result, an erroneous determination that the motor is rotating in the forward / reverse rotation is made, and the normal value J is erroneously set to “0”. In this case, the difference (Pi−Pi−1) between the counter value Pi of the position counter P when the current edge occurs and the counter value Pi−1 of the position counter P when the edge occurs is “4”. The first correction value ΔP (= “J− (Pi−Pi−1)”) is set to “−4”. Then, since the correction for the first correction value ΔP is added to the counter value of the position counter P, the counter value is erroneously set to “−4” as indicated by the black arrow Y5 in FIG. Will be made smaller.

  Accordingly, when the counter value of the electrical angle counter E changes as shown by the broken line L5 in FIG. 11 (f) due to the generation of the noise shown by the broken line L4 in FIG. 11 (b), FIG. The correction for the first correction value ΔP indicated by the black arrows Y3, Y4, Y5 is erroneously added to the counter value of the position counter P. As a result, the counter value of the position counter P deviates from a value (solid line) corresponding to the actual rotation angle of the brushless motor 47, as indicated by a broken line L6 in the drawing.

[Motor reverse rotation]
During reverse rotation of the brushless motor 47, as indicated by a broken line L4 in FIG. 11B, noise is generated in the signal from the electrical angle sensor S2, and the noise is generated from the rising edge of the pulse signal from the electrical angle sensor S3. If they overlap, the output patterns of the signals from the electrical angle sensors S1 to S3 at the timings f, e, and d when the noise is generated become different from those at normal times. The counter value of the electrical angle counter E changes to an incorrect value as indicated by a broken line L11 in FIG.

  Here, the output pattern of the signals from the electrical angle sensors S1 to S3 at the timings f, e, and d, the counter value of the electrical angle counter E, the time when the previous edge occurred in the signals from the electrical angle sensors S1 to S3, and the current time FIG. 13A shows the motor status, normal value J, difference (Pi−Pi−1), and first correction value ΔP (= “J− (Pi−Pi−1)”) from when the edge is generated. Shown in

  The timing f corresponds to the rising edge of the noise. Therefore, at the timing f, due to the rising edge of the noise, the signals from the electrical angle sensors S1 to S3 are “H”, “H”, and “L”, respectively, and the counter value of the electrical angle counter E is “ It changes from “4” to “5”. Therefore, the motor status at the time of the previous edge occurrence and the motor status at the occurrence of the current edge in the signals from the electrical angle sensors S1 to S3 are “ccw” and “cw”, respectively. As a result, an erroneous determination that the motor is rotating in the forward / reverse rotation is made, and the normal value J is erroneously set to “0”. In this case, the difference (Pi−Pi−1) between the counter value Pi of the position counter P when the current edge occurs and the counter value Pi−1 of the position counter P when the edge occurs is “−4”. Therefore, the first correction value ΔP (= “J− (Pi−Pi−1)”), which is a deviation amount of the difference (Pi−Pi−1) from the normal value J, is set to “4”. Since the correction for the first correction value ΔP is added to the counter value of the position counter P, the counter value is erroneously increased by “4” as shown by the black arrow Y8 in FIG. It will be.

  The timing e corresponds to the rising edge of the pulse signal from the electrical angle sensor S3. At this timing e, due to the generation of the noise, all the electrical angle sensors S1 to S3 become the high signal “H” as shown in FIG. It is held at the value “5”. As a result, the motor status when the current edge occurs in the signals from the electrical angle sensors S1 to S3 is “hold”, and the normal value J is set to “0”. Further, the difference (Pi−Pi−1), which is the change amount of the position counter P from the timing f to the timing e, is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “0”, and the correction for the first correction value ΔP is added to the counter value of the position counter P. There is no.

  Timing d corresponds to the falling edge of the noise. At this timing d, due to the falling edge of the noise, the signals from the electrical angle sensors S1 to S3 become “H”, “L”, and “H”, respectively, and the counter value of the electrical angle counter E is normal. It shows an unobtainable change, that is, a change in which an integer value is skipped by one in the opposite direction from “5” to “3”. The change of the counter value of the electrical angle counter E at the time of the occurrence of the current edge is regarded as a change in the reverse direction, and the motor status at the time of the occurrence of the current edge is set to “ccw” as indicated by hatching in the figure. Then, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “cw” and “ccw”, respectively. As a result, the normal value J is set to “0”. Further, the difference (Pi−Pi−1), which is the change amount of the position counter P from the timing e to the timing d, is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “0”, and the correction for the first correction value ΔP is added to the counter value of the position counter P. There is no.

  Accordingly, when the counter value of the electrical angle counter E changes as shown by the broken line L11 in FIG. 11 (h) due to the generation of noise shown by the broken line L4 in FIG. 11 (b), FIG. 11 (i). The correction for the first correction value ΔP (= 4) indicated by the black arrow Y8 is erroneously added to the counter value of the position counter P. As a result, the counter value of the position counter P deviates from a value (solid line) corresponding to the actual rotation angle of the brushless motor 47, as indicated by a broken line L8 in the drawing.

  Further, during reverse rotation of the brushless motor, noise is generated in the signal from the electrical angle sensor S2, as indicated by the broken line L1 in FIG. 11B, and the noise falls on the pulse signal from the electrical angle sensor S1. If it overlaps with the edge, the output pattern of the signals from the electrical angle sensors S1 to S3 at the timings c, b, a where the noise is generated becomes different from that at the normal time. The counter value of the electrical angle counter E changes erroneously as shown by the broken line L12 in FIG.

  Here, the output pattern of the signals from the electrical angle sensors S1 to S3 at the timings c, b, and a, the counter value of the electrical angle counter E, the time when the previous edge occurred in the signals from the electrical angle sensors S1 to S3, and the current time FIG. 13B shows the motor status, normal value J, difference (Pi−Pi−1), and first correction value ΔP (= “J− (Pi−Pi−1)”) when the edge is generated. Shown in In the figure, after the timing a, the output pattern of the signals from the electrical angle sensors S1 to S3 at the timing a when the edges of the pulse signals from the electrical angle sensors S1 to S3 first occur, Also shown are the value, the motor status between the occurrence of the previous edge and the current edge, the normal value J, the difference (Pi−Pi−1), and the first correction value ΔP.

  Timing c corresponds to the rising edge of the noise. For this reason, at timing c, due to the rising edge of the noise, all the signals from the electrical angle sensors S1 to S3 become the high signal “H”, and the counter value of the electrical angle counter E is the value up to that time. 3 ". As a result, the motor status when the current edge occurs in the signals from the electrical angle sensors S1 to S3 is “hold”, and the normal value J is set to “0”. In this case, the difference (Pi−Pi−1) between the counter value Pi of the position counter P when the current edge occurs and the counter value Pi−1 of the position counter P when the edge occurs is “−4”. Therefore, the first correction value ΔP (= “J− (Pi−Pi−1)”), which is a deviation amount of the difference (Pi−Pi−1) from the normal value J, is set to “4”. Since the correction for the first correction value ΔP is added to the counter value of the position counter P, the counter value is increased by “4” as indicated by the black arrow Y10 in FIG. become.

  Timing b corresponds to the falling edge of the pulse signal from the electrical angle sensor S1. At this timing b, due to the occurrence of the noise, as shown in FIG. 13B, the signals from the electrical angle sensors S1 to S3 become “L”, “H”, “H”, respectively, and the electrical angle The counter value of the counter E usually shows an impossible change, that is, a change in which the integer value is skipped by one in the opposite direction from “3” to “1”. The change of the counter value of the electrical angle counter E at the time of the occurrence of the current edge is regarded as a change in the reverse direction, and the motor status at the time of the occurrence of the current edge is set to “ccw” as indicated by hatching in the figure. Then, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “ccw” and “ccw”, respectively. As a result, the normal value J is set to “−4”. Further, the difference (Pi−Pi−1), which is the change amount of the position counter P from the timing c to the timing b, is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “−4”, and the correction for the first correction value ΔP is added to the counter value of the position counter P. Therefore, the counter value is decreased by “−4” as indicated by the black arrow Y11 in FIG.

  Timing a corresponds to the falling edge of the noise. At this timing a, due to the falling edge of the noise, the signals from the electrical angle sensors S1 to S3 are “L”, “L”, and “H”, respectively, and the counter value of the electrical angle counter E is “1”. To "2". Therefore, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “ccw” and “cw”, respectively, and the normal value J is set to “0” based thereon. Further, the difference (Pi−Pi−1), which is the change amount of the position counter P from the timing b to the timing a, is “0”. For this reason, the first correction value ΔP (= “J− (Pi−Pi−1)”) is “0”, and the correction for the first correction value ΔP is added to the counter value of the position counter P. There is no.

  The timing z corresponds to the generation of an edge of the pulse signal from the first electrical angle sensors S1 to S3 after the timing a. At this timing z, the signals from the electrical angle sensors S1 to S3 become “L”, “H”, and “H”, respectively, and the counter value of the electrical angle counter E changes from “2” to “1”. Therefore, the motor statuses at the time of the previous edge occurrence and the current edge occurrence are “cw” and “ccw”, respectively. As a result, an erroneous determination that the motor is rotating in the forward / reverse rotation is made, and the normal value J is erroneously set to “0”. In this case, the difference (Pi−Pi−1) between the counter value Pi of the position counter P when the current edge occurs and the counter value Pi−1 of the position counter P when the edge occurs is “−4”. Therefore, the first correction value ΔP (= “J− (Pi−Pi−1)”) is set to “4”. Since the correction for the first correction value ΔP is added to the counter value of the position counter P, the counter value is erroneously increased by “4” as indicated by the black arrow Y12 in FIG. It will be.

  Accordingly, when the counter value of the electrical angle counter E changes as shown by the broken line L12 in FIG. 11 (h) due to the generation of noise shown by the broken line L1 in FIG. 11 (b), FIG. 11 (i). The correction for the first correction value ΔP indicated by the black arrows Y10, Y11, and Y14 is erroneously added to the counter value of the position counter P. As a result, the counter value of the position counter P deviates from a value (solid line) corresponding to the actual rotation angle of the brushless motor 47, as indicated by a broken line L9 in the drawing.

  As described above, when noise (broken line L1 or broken line L4) is generated in the signals output from the electrical angle sensors S1 to S3, and the noise overlaps with the edges of the pulse signals from the electrical angle sensors S1 to S3, the position counter. The counter value of P does not correspond to the actual rotation angle of the brushless motor 47 due to erroneous correction of the first correction value ΔP. As a result, the actual rotation angle of the brushless motor 47 detected based on the counter value of the position counter P (more precisely, the stroke counter S) becomes inaccurate, and the brushless motor 47 is driven based on the rotation angle and the like, Even if it is attempted to control the valve characteristic of the valve 9 to the target characteristic, it cannot be performed correctly, leading to an adverse effect on engine operation.

  When noise is generated in the signals output from the electrical angle sensors S1 to S3, the noise may not overlap the edges of the pulse signals from the electrical angle sensors S1 to S3. In this case, the counter value of the position counter P deviates from a value corresponding to the actual rotation angle of the brushless motor 47 by the correction of the first correction value ΔP at the rising edge of the noise, but at the falling edge of the noise. A correction corresponding to the first correction value ΔP is added to the counter value of the position counter P in the reverse direction. As a result, the above-described deviation in the counter value of the position counter P is eliminated by the next edge generation of the pulse signal. For this reason, even if noise occurs in the signals output from the electrical angle sensors S1 to S3, if the noise does not overlap with the edges of the pulse signals from the electrical angle sensors S1 to S3, the above-described problems occur. It does not occur.

Next, suppression of the above-described problems performed in the present embodiment will be described.
In this embodiment, when the correction of the first correction value ΔP is performed on the counter value of the position counter P due to noise generated in the signals from the electric angle sensors S1 to S3, the electric angle Focusing on the fact that the counter value of the counter E indicates a change that cannot normally occur, processing for invalidating the erroneous correction by the first correction value ΔP is executed when such a change occurs.

  Specifically, first, in order to enable the above processing to be executed, the counter value of the electrical angle counter E showed a change in which an integer value, which is a normal change in the motor forward rotation direction, is skipped by one in the forward direction. "Cw2" is added as the motor status. Furthermore, “ccw2” is added as the motor status when the counter value of the electrical angle counter E shows a change in which an integer value, which is a normal change in the reverse direction of the motor, is skipped by one in the reverse direction.

  Then, using the motor status to which “cw2” and “ccw2” are added, it is determined whether the rotation state of the brushless motor 47 is normal rotation, reverse rotation, or normal / reverse rotation reversal. Like that.

  That is, as shown in FIG. 14, the motor statuses at the time of the previous edge generation and the current edge generation in the signals from the electrical angle sensors S1 to S3 both represent motor forward rotations such as “cw” and “cw2”. If it is, it is determined that the brushless motor 47 is rotating forward. If the motor statuses at the time of the previous edge occurrence and the current edge occurrence both indicate reverse motor rotation such as “ccw” and “ccw2”, it is determined that the brushless motor 47 is in reverse rotation. To do. Furthermore, the motor status indicates the forward rotation of the motor (“cw”, “cw2”) and the reverse rotation of the motor (“ccw” and “ccw2”) when the previous edge occurs and when the current edge occurs. If it is different from the above, it is determined that the brushless motor 47 is in reverse rotation.

  Further, the normal value J set based on the motor status at the time of the previous edge generation and the current edge generation is set as shown in the table of FIG. 15 according to the motor status. In the figure, the hatched portion indicates an additional portion obtained by adding “cw2” and “ccw2” as the motor status. As can be seen from this figure, when the previous edge occurrence and the current edge occurrence, the motor status represents the motor forward rotation ("cw", "cw2") to the same motor forward rotation ("cw"). , “Cw2”), the normal value J is set to “4”. Also, the motor status indicating reverse motor rotation ("ccw" and "ccw2") from the time of the previous edge generation and the current edge generation to the same motor reverse rotation ("ccw" and "ccw2") When the value has changed to normal, the normal value J is set to “−4”. Furthermore, when the previous edge occurs and when the current edge occurs, the motor status indicates normal motor rotation (“cw”, “cw2”) and the reverse motor rotation (“ccw” and “ccw2”). When the value changes between the normal values J, the normal value J is set to “0”.

  Subsequently, a second correction value ΔPr for invalidating the correction of the position counter P by the first correction value ΔP is set according to the motor status when the current edge occurs, as shown in FIG.

  With respect to the second correction value ΔPr set in this way, when the motor status at the time of the current edge generation is “cw2”, the position sensors S4 and S5 are used between the edges of the pulse signals from the electrical angle sensors S1 to S3. “N = (4)” in relation to the number of edges n of the output pulse signal. Here, the motor status being “cw2” indicates that the counter value of the electrical angle counter E has changed in the normal motor rotation direction at the time of the occurrence of the current edge, that is, the counter value is adjusted. It means that the numerical value is changed one by one in the forward direction. The second correction value ΔPr is set to “−n (= −4)” in relation to the number of edges n when the motor status at the time of occurrence of the current edge is “ccw2”. Here, that the motor status is “ccw2” indicates that the counter value of the electrical angle counter E is not normally changed in the reverse direction of the motor when the current edge occurs, that is, the counter value is an integer value. It means that the change is shown by skipping one in the opposite direction. If the motor status at the time of the current edge generation is other than “cw2” and “ccw2” described above, the second correction value ΔPr is “0”.

  Then, by adding the correction for the second correction value ΔPr set in this way to the counter value of the position counter P, the deviation of the counter value from the value corresponding to the actual rotation angle of the brushless motor 47 is affected. It becomes possible to invalidate the correction by the first correction value ΔP that exerts. Thereby, it is possible to avoid the counter value of the position counter P from deviating from the value corresponding to the actual rotation angle of the brushless motor 47 due to the erroneous correction by the first correction value ΔP.

  As described above, adding “cw2” and “ccw2” to the motor status, setting the normal value J as shown in FIG. 16, and correcting the second correction value ΔPr by the position counter P By adding to the counter value, the tables in FIGS. 12 and 13 can be changed to the tables shown in FIGS. 17 and 18.

  In these figures, the tables of FIGS. 12 (a) and 12 (b) and FIGS. 13 (a) and 13 (b) are shown in FIGS. 17 (a) and 17 (b) and FIGS. 18 (a) and (b), respectively. Corresponds to the table in b). The hatched portion in the motor status column of the tables of FIGS. 17 and 18 is a portion changed from the tables of FIGS. 12 and 13 by adding “cw2” and “ccw2” to the motor status. Also, the column of the second correction value ΔPr in the tables of FIGS. 17 and 18 is a portion added to the tables of FIGS. 12 and 13.

  Next, with respect to the effect of adding the correction of the second correction value ΔPr to the counter value of the position counter P, the case where the motor is rotating forward and the case where the motor is rotating backward is taken as an example in FIG. Based on these timing charts, detailed description will be given with reference to the tables of FIGS.

[During motor forward rotation]
If noise occurs as shown by the broken line L1 in FIG. 11B during the forward rotation of the brushless motor 47, the counter of the position counter P shown in FIG. 11G due to erroneous correction for the first correction value ΔP. As described above, the value decreases by “−4” as indicated by the broken line L3 with respect to the value (solid line) corresponding to the actual rotation angle of the brushless motor 47. In this case, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is an erroneous correction for the first correction value ΔP at the timing a (black arrow in FIG. 11G). That is, it was influenced by Y1).

  However, at timing c, as shown in FIG. 17A, the motor status when the current edge is generated is “cw2”, and based on this, the second correction value ΔPr is set to “4”. The value “4” of the second correction value ΔPr at this time is a value obtained by inverting the sign of the first correction value ΔP (“−4”) at the timing a. The motor status when the current edge occurs at timings a and b is set to “0” because it is not “cw2” or “ccw2”. Then, the correction for the second correction value ΔPr set as described above is added to the counter value of the position counter P.

  Thus, when the correction for the second correction value ΔPr is added to the counter value of the position counter P, the correction of the position counter P for the first correction value ΔP at the timing a is invalidated, and the position The counter value of the counter P changes to a value (solid line) corresponding to the actual rotation angle of the brushless motor 47 as indicated by a white arrow Y2 in FIG. Thereby, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is corrected.

  In addition, when noise is generated during the forward rotation of the brushless motor 47 as shown by the broken line L4 in FIG. 11B, the position counter P shown in FIG. 11G is caused by erroneous correction for the first correction value ΔP. It is also described above that the counter value becomes smaller by “−4” as shown by the broken line L6 with respect to the value (solid line) corresponding to the actual rotation angle of the brushless motor 47. In this case, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is an erroneous correction corresponding to the first correction value ΔP at the timing g (black arrow in FIG. 11G). This means that it was influenced by Y5).

  However, at timing e, as shown in FIG. 17B, the motor status when the current edge is generated is “cw2”, and based on this, the second correction value ΔPr is set to “4”. The value “4” of the second correction value ΔPr at this time is a value obtained by inverting the sign of the first correction value ΔP (“−4”) at the timing g. The motor status at the time of occurrence of the current edge at timings d, f, and g is set to “0” because it is not “cw2” or “ccw2”. Then, the correction for the second correction value ΔPr set as described above is added to the counter value of the position counter P.

  When the correction for the second correction value ΔPr is added to the counter value of the position counter P in this way, the counter value is an actual rotation angle of the brushless motor 47 as indicated by a white arrow Y6 in FIG. Is increased by “4” from the value corresponding to, and thereafter changes as indicated by a broken line L7. Thus, when the counter value of the position counter P is decreased by “−4” as indicated by the black arrow Y7 due to the erroneous correction for the first correction value ΔP at the timing g, the counter value is reduced to the brushless motor 47. This corresponds to the value (solid line) corresponding to the actual rotation angle. In other words, the correction of the position counter P corresponding to the second correction value ΔPr at the timing e invalidates the correction of the position counter P corresponding to the first correction value ΔP at the timing g. is there. As described above, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is corrected.

[Motor reverse rotation]
During the reverse rotation of the brushless motor 47, if noise occurs as shown by the broken line L4 in FIG. 11B, the counter of the position counter P shown in FIG. 11G is caused by erroneous correction for the first correction value ΔP. As described above, the value increases by “4” as indicated by the broken line L8 with respect to the value (solid line) corresponding to the actual rotation angle of the brushless motor 47. In this case, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is an erroneous correction for the first correction value ΔP at the timing f (black arrow in FIG. 11G). That is, it was influenced by Y8).

  However, at timing d, as shown in FIG. 18A, the motor status when the current edge is generated becomes “ccw2”, and based on this, the second correction value ΔPr is set to “−4”. The value “−4” of the second correction value ΔPr at this time is a value obtained by inverting the sign of the first correction value ΔP (“4”) at the timing f. The motor status at the time of occurrence of the current edge at timings f and e is set to “0” because it is not “cw2” or “ccw2”. Then, the correction for the second correction value ΔPr set as described above is added to the counter value of the position counter P.

  Thus, when the correction for the second correction value ΔPr is added to the counter value of the position counter P, the correction of the position counter P for the first correction value ΔP at the timing f is invalidated, and the position The counter value of the counter P changes to a value (solid line) corresponding to the actual rotation angle of the brushless motor 47 as indicated by a white arrow Y9 in FIG. Thereby, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is corrected.

  Further, when noise occurs during reverse rotation of the brushless motor 47 as indicated by a broken line L1 in FIG. 11B, the position counter P shown in FIG. 11G is caused by erroneous correction for the first correction value ΔP. It has also been described above that the counter value increases by “4” as indicated by the broken line L9 with respect to the value corresponding to the actual rotation angle of the brushless motor 47 (solid line). In this case, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is an erroneous correction for the first correction value ΔP at the timing z (black arrow in FIG. 11G). That is, it was influenced by Y12).

  However, at timing b, as shown in FIG. 18B, the motor status when the current edge is generated is “ccw2”, and based on this, the second correction value ΔPr is set to “−4”. The value “−4” of the second correction value ΔPr at this time is a value obtained by inverting the sign of the first correction value ΔP (“4”) at the timing z. The motor status at the time of occurrence of the current edge at timings c, a, and z is set to “0” because it is not “cw2” or “ccw2”. Then, the correction for the second correction value ΔPr set as described above is added to the counter value of the position counter P.

  When the correction for the second correction value ΔPr is added to the counter value of the position counter P in this way, the counter value is an actual rotation angle of the brushless motor 47 as indicated by a white arrow Y13 in FIG. Is decreased by “−4” from the value corresponding to, and thereafter changes as indicated by a broken line L10. As a result, when the counter value of the position counter P increases by “4” as indicated by the black arrow Y12 due to the erroneous correction of the first correction value ΔP at the timing z, the counter value is the actual value of the brushless motor 47. This corresponds to the value (solid line) corresponding to the rotation angle. In other words, the correction of the position counter P corresponding to the first correction value ΔP at the timing z is invalidated by the correction of the position counter P corresponding to the second correction value ΔPr at the timing b. is there. As described above, the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 is corrected.

  Next, the procedure for calculating the second correction value ΔPr and the procedure for correcting the position counter using the second correction value ΔPr will be described with reference to the flowchart of FIG. 19 showing the position counter correction invalidation routine. This position counter correction invalidation routine is periodically executed through the electronic control unit 50 at intervals shorter than the time intervals corresponding to the edge intervals of the pulse signals from the position sensors S4 and S5.

  In the routine, when an edge occurs in the signals from the electrical angle sensors S1 to S3 (S201: YES), it is determined whether or not the motor status at the time of the current edge generation is “cw2” (S202); Then, it is determined whether or not the motor status at the time of the current edge generation is “ccw2” (S203).

  If the motor status at the time of occurrence of the current edge is “cw2” (S202: YES), that is, the counter value of the electrical angle counter E is changed to an integer value that is a normally impossible change in the motor forward rotation direction. The second correction value ΔPr is set to “n (= 4)” in relation to the number of edges n described above (S204). On the other hand, if the motor status at the time of the occurrence of the current edge is “ccw2” (S203: YES), the counter value of the electrical angle counter E is changed to an integer value that is a change that is not normally possible in the motor reverse rotation direction. It is determined that one change has been shown, and the second correction value ΔPr is set to “−n (= −4)” in relation to the number of edges n described above (S205). Further, if the motor status at the time of the current edge generation is neither “cw2” nor “ccw2” (both NO in S202 and S203), the second correction value ΔPr is set to “0” (S206). .

  After the second correction value ΔPr is set in this way, correction for the second correction value ΔPr is added to the counter value of the position counter P (S207). Thereby, the erroneous correction of the first correction value ΔP with respect to the position counter P is invalidated, and the deviation of the counter value of the position counter P from the value corresponding to the actual rotation angle of the brushless motor 47 due to the erroneous correction. Will be corrected.

According to the embodiment described in detail above, the following effects can be obtained.
(1) Every time the edge of the pulse signal from the electrical angle sensors S1 to S3 is generated, the counter value Pi-1 of the position counter P when the previous edge is generated and the counter value Pi of the position counter P when the current edge is generated The difference (Pi-Pi-1) is calculated. This difference (Pi−Pi−1) is reflected when the counter value of the position counter P is deviated from a value corresponding to the actual rotation angle of the brushless motor 47. That is, the difference (Pi-Pi-1) deviates from the normal value J by the amount of deviation. Accordingly, the shift amount “J− (Pi−Pi−1)” of the difference (Pi−Pi−1) with respect to the normal value J is set as the first correction value ΔP, and the correction for the first correction value ΔP is performed by the position counter. By adding to the counter value of P, it is possible to eliminate a deviation from the value corresponding to the actual rotation angle of the brushless motor 47 in the counter value. Further, in order to calculate the difference (Pi−Pi−1) for obtaining the first correction value ΔP, it is sufficient to have the electrical angle sensors S1 to S3 used for driving the brushless motor 47, and the above-described deviation is eliminated. Therefore, it is not necessary to provide a new sensor or the like.

  (2) When noise is generated in the signals from the electrical angle sensors S1 to S3, and the noise overlaps with the edges of the pulse signals from the other electrical angle sensors S1 to S3, the noise is transmitted from the electrical angle sensors S1 to S3. It is mistaken for a pulse signal, and the counter value of the electrical angle counter E changes to an incorrect value. When the counter value of the electrical angle counter E changes to an incorrect value in this way, the rotational state of the brushless motor 47 determined based on the counter value is different from the actual state, and is set according to the motor rotational state. The normal value J thus made does not correspond to the actual motor rotation state. Then, due to the abnormality of the normal value J described above, the first correction value ΔP which is the deviation “J− (Pi−Pi−1)” of the difference (Pi−Pi−1) with respect to the normal value J. Is an incorrect value. If the counter value of the position counter P is erroneously corrected by the first correction value ΔP, the counter value deviates from a value corresponding to the actual rotation angle of the brushless motor 47. As a result, the rotation angle of the brushless motor 47 detected based on the counter value of the position counter P becomes an incorrect value.

  However, when the electrical angle counter E changes to an incorrect value due to the occurrence of noise in the signals of the electrical angle sensors S1 to S3, the counter value of the position counter P deviates from the actual rotation angle of the brushless motor 47 due to this. Indicates a change in which the counter value of the electrical angle counter E is not normally possible. Focusing on such a change in the counter value of the electrical angle counter E, when it is determined that the change has occurred, a process for invalidating the erroneous correction by the first correction value ΔP is executed. Specifically, the counter value of the electrical angle counter E indicates a change that cannot be normally performed. The counter value indicates a change by skipping an integer value, and when the motor status becomes “cw2” or “ccw2”, A second correction value ΔPr for invalidating the erroneous correction due to the first correction value ΔP is set. Then, the correction of the second correction value ΔPr is added to the counter value of the position counter P. As a result, the erroneous correction for the first correction value ΔP with respect to the counter value of the position counter P is invalidated, and the counter value is prevented from deviating from a value corresponding to the actual rotation angle of the brushless motor 47. it can. Accordingly, it is possible to avoid an inaccurate value of the rotation angle of the brushless motor 47 detected based on the counter value of the position counter P (more precisely, the stroke counter S). Then, when the motor 47 is driven based on the rotation angle of the brushless motor 47 detected based on the counter value of the position counter P and the valve lift variable mechanism 14 is to be driven and controlled, it cannot be performed correctly and the engine operation is started. It will no longer lead to adverse effects.

  (3) During forward rotation of the brushless motor 47, when the counter of the electrical angle counter E shows a change in the direction opposite to the motor rotation direction due to the generation of the noise, for example, the timing a in FIG. Alternatively, at the timing g in FIG. 17B, if the normal value J is originally supposed to be set to “4” in relation to the number of edges n described above, it is set to “0”. As a result, the first correction value ΔP (= “J− (Pi−Pi−1)”), which is a deviation amount of the difference (Pi−Pi−1) from the normal value J, becomes the timing a in FIG. Or at the timing g in FIG. 17B, it is used for correction of the position counter P in a state where it was originally “0” but erroneously set to “−4”, and the counter value of the position counter P is incorrect. It is corrected. However, the counter value of the electrical angle counter E shows a change in which an integer value is skipped by one in the forward direction (motor forward rotation direction), for example, timing c in FIG. 18 (a) or timing e in FIG. 17 (b). When the motor status becomes “cw2”, the second correction value ΔPr is set to “4” and used for correction of the position counter P. The second correction value ΔPr at this time is a value set to “n (= 4)” in relation to the number of edges n described above, and the first correction value ΔP causing the erroneous correction. It is a value obtained by inverting the sign. Therefore, by adding the correction for the second correction value ΔPr to the counter value of the position counter P, the erroneous correction of the position counter P by the first correction value ΔP can be accurately invalidated.

  Further, during the reverse rotation of the brushless motor 47, when the counter of the electrical angle counter E shows a change in the direction opposite to the motor rotation direction due to the generation of the noise, for example, the timing f in FIG. At the timing z in FIG. 18B, if the normal value J is originally supposed to be set to “−4” in relation to the number of edges n described above, it is set to “0”. As a result, the first correction value ΔP (= “J− (Pi−Pi−1)”), which is a deviation amount of the difference (Pi−Pi−1) from the normal value J, becomes the timing f in FIG. Or at the timing z in FIG. 18B, it is used to correct the position counter P in a state where it was originally “0” but erroneously set to “4”, and the counter value of the position counter P is erroneously corrected. Is done. However, the counter value of the electrical angle counter E shows a change in which the integer value is skipped by one in the positive direction. For example, the motor status is “ccw2” as shown in timing d of FIG. 18A or timing b of FIG. ”, The second correction value ΔPr is set to“ −4 ”and used for correcting the position counter P. The second correction value ΔPr at this time is a value set to “−n = (− 4)” in relation to the number of edges n described above, and the first correction value that causes the erroneous correction. This is a value obtained by inverting the sign of ΔP. Therefore, by adding the correction for the second correction value ΔPr to the counter value of the position counter P, the erroneous correction of the position counter P by the first correction value ΔP can be accurately invalidated.

  (4) In order to invalidate the erroneous correction of the position counter P by the first correction value ΔP, the second correction value ΔPr is set to either “n (= 4)” or “−n = (− 4)”. When setting, the setting is performed depending on whether the motor status is “cw2” or “ccw2”. This “cw2” means the occurrence of a change in which the integer value, which is a change that is not normally possible in the forward rotation direction of the electric angle counter E, is skipped by one in the forward direction. Further, “ccw2” means the occurrence of a change in which the integer value, which is a normally impossible change in the motor reverse rotation direction, of the electric angle counter E is skipped in the reverse direction. Therefore, the second correction value ΔPr is set to “n (= 4)” based on the fact that the motor status is “cw2”, and the second correction value ΔPr is set to “n (= 4)” based on the fact that the motor status is “ccw2”. By appropriately setting “−n = (− 4)”, the second correction value ΔPr is appropriately set to “n (= 4)” or “−n = (− 4)”. Can do.

In addition, the said embodiment can also be changed as follows, for example.
It is also possible to change the edge interval of the pulse signal from each electrical angle sensor through a change in the number of electrical angle sensors or a change in the number of poles of a multipolar magnet that is a detection target of the sensor.

It is also possible to change the edge interval of the pulse signal from each position sensor through changing the number of position sensors or changing the number of poles of a multipolar magnet that is a detection target of the sensors.
The electric angle counter E is assumed that each successive integer value within the range of “0” to “m” is applied as the counter value, and the above “m” is set to “5”, but the value is changed as appropriate. It is also possible. In this case, the number and position of the electrical angle sensors and the number of poles of the multipolar magnet that is a detection target of the electrical angle sensors are appropriately changed.

  The number of edges n of the pulse signals output from the position sensors S4 and S5 is set to “4” between the edges of the pulse signals from the electrical angle sensors S1 to S3, but the rotation angle of the brushless motor 47 is detected for the value. Any value corresponding to the edge interval of the pulse signals from the position sensors S4 and S5 that can ensure the accuracy may be used, and can be appropriately changed to an integer value of “2” or more. Thus, when the number of edges n is changed, the number and position of the position counters and the number of poles of the multipolar magnet that is a detection target of the position sensors are appropriately changed.

  Instead of providing position sensors S4 and S5 that output a pulse signal according to the magnetism of a multipolar magnet that rotates integrally with the brushless motor 47, other sensors that output a pulse signal as the brushless motor 47 rotates, such as an optical type It is also possible to provide a sensor. In this case, a plurality of optical sensors each including a light emitting element and a light receiving element are provided in the circumferential direction on the side of the thickness direction of the disc with the slit that rotates integrally with the brushless motor 47, and each of the sensors is rotated when the brushless motor 47 rotates. It is conceivable to output a pulse signal. In this case, the output pattern of the pulse signal from each sensor is adjusted according to the slit pattern in the disc with slit and the number and position of the optical sensors.

  In the above embodiment, the variable valve lift mechanism is illustrated that converts the rotational motion of the brushless motor 47 into the motion of the control shaft 16 in the axial direction and is driven through the axial displacement of the control shaft 16. The variable valve lift mechanism is not limited to this. For example, it is possible to employ a variable valve lift mechanism that is driven by directly receiving the rotational motion of the brushless motor 47.

  -Although this invention was applied to the brushless motor 47 which drives the valve lift variable mechanism 14, this invention can also be applied to the brushless motor which drives various other mechanisms.

The expanded sectional view which shows the structure around the cylinder head of the engine to which the variable valve lift mechanism of this embodiment is applied. 6 is a schematic diagram showing a drive mechanism for displacing a control shaft in the axial direction to drive the variable valve lift mechanism, and a control device for driving and controlling the drive mechanism. (A) to (h) are the waveforms of the pulse signals of the electrical angle sensors S1 to S3, the waveforms of the pulse signals of the position sensors S4 and S5 with respect to the change in the rotation angle of the brushless motor, the transition of the counter value of the electrical angle counter E, 6 is a timing chart showing the transition of the counter value of the position counter P and the transition of the counter value of the stroke counter S. The flowchart which shows the procedure which changes the counter value of the electrical angle counter E, the position counter P, and the stroke counter S. (A) is a table | surface which shows the change aspect of the counter value of the electrical angle counter E which changes according to the signal from electrical angle sensor S1-S3, (b) is the position counter P according to the signal from position sensor S4, S5. The table which shows the addition / subtraction mode of the counter value of. (A) to (e) are pulse signal waveforms from the position sensors S4 and S5 with respect to changes in the rotation angle of the brushless motor 47, changes in the counter value of the electrical angle counter E, and changes in the counter value of the position counter P. The timing chart which shows. (A) is a table showing the addition / subtraction mode of the counter value of the position counter P according to the signals from the position sensors S4, S5 at the timings a, b, c of FIG. 6 (d), and (b) is the table of FIG. The table showing the addition / subtraction mode of the counter value of the position counter P according to the signals from the position sensors S4, S5 at the timings c, b, a). (A)-(e) is a time chart which shows the transition of the waveform of the pulse signal from electric angle sensor S1-S3 with respect to time passage, the counter value of electric angle counter E, and the motor status. The table | surface which shows the relationship between the motor status at the time of the last edge generation in this time and the edge generation in the pulse signal from electrical angle sensor S1-S3, and the rotation state of a brushless motor. The flowchart which shows the correction procedure by 1st correction value (DELTA) P with respect to the counter value of the position counter P. FIG. (A) to (i) are waveforms of pulse signals from the electrical angle sensors S1 to S3 with respect to changes in the rotation angle of the brushless motor 47, waveforms of pulse signals from the position sensors S4 and S5, and a counter value of the electrical angle counter E. And a timing chart showing the transition of the counter value of the position counter P. (A) and (b) are the output patterns of signals from the electrical angle sensors S1 to S3 at the timings a to g in FIG. 11 during forward rotation of the motor, the counter value of the electrical angle counter E, and the electrical angle sensors S1 to S3. Table showing motor status, normal value J, difference (Pi-Pi-1), and first correction value [Delta] P between the previous edge generation and the current edge generation in the signal from. (A) and (b) are signal output patterns from the electrical angle sensors S1 to S3 at the timings g to a and z in FIG. 11 during reverse rotation of the motor, the counter value of the electrical angle counter E, and the electrical angle sensor S1. Table showing motor status, normal value J, difference (Pi−Pi−1), and first correction value ΔP between the previous edge generation and the current edge generation in the signals from .about.S3. The table | surface which shows the relationship between the motor status at the time of the last edge generation in this time and the edge generation in the pulse signal from electrical angle sensor S1-S3, and the rotation state of a brushless motor. The table | surface which shows the relationship between the motor status at the time of the last edge generation | occurrence | production in the pulse signal from electrical angle sensor S1-S3 and this edge generation | occurrence | production, and the normal value J of a difference (Pi-Pi-1). The table | surface which shows the setting aspect of 2nd correction value (DELTA) Pr according to the motor status at the time of edge generation this time. (A) and (b) are the output patterns of signals from the electrical angle sensors S1 to S3 at the timings a to g in FIG. 11 during forward rotation of the motor, the counter value of the electrical angle counter E, and the electrical angle sensors S1 to S3. Shows the motor status, normal value J, difference (Pi−Pi−1), first correction value ΔP, and second correction value ΔPr between the previous edge generation and the current edge generation. table. (A) and (b) are signal output patterns from the electrical angle sensors S1 to S3 at the timings g to a and z in FIG. 11 during reverse rotation of the motor, the counter value of the electrical angle counter E, and the electrical angle sensor S1. Motor status, normal value J, difference (Pi−Pi−1), first correction value ΔP, and second correction value ΔPr between the previous edge generation and the current edge generation in the signals from .about.S3. Table showing. The flowchart which shows the procedure which invalidates the erroneous correction by the 1st correction value with respect to the counter value of the position counter P.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Cylinder head, 3 ... Cylinder block, 5 ... Piston, 6 ... Combustion chamber, 7 ... Intake passage, 8 ... Exhaust passage, 9 ... Intake valve, 10 ... Exhaust valve, 11 ... Intake camshaft, 11a DESCRIPTION OF SYMBOLS ... Intake cam, 12 ... Exhaust cam shaft, 12a ... Exhaust cam, 14 ... Valve lift variable mechanism, 15 ... Rocker shaft, 16 ... Control shaft, 17 ... Input arm, 18 ... Output arm, 19 ... Roller, 20 ... Coil spring , 21 ... Rocker arm, 22 ... Rush adjuster, 23 ... Roller, 24 ... Valve spring, 47 ... Brushless motor, 48 ... Conversion mechanism, 50 ... Electronic control device (drive device, calculation means, setting means, first correction means, (Second correction means), 51 ... accelerator position sensor, 52 ... throttle position sensor, 53 ... airflow Meta, 54 ... crank position sensor, 55 ... ignition switch, 56 ... nonvolatile memory, S1 to S3 ... electric angle sensors, S4, S5 ... position sensor.

Claims (5)

According to the output pattern of the pulse signal output from the brushless motor that is driven to rotate within a predetermined rotation angle range, and the phase of the plurality of electrical angle sensors provided on the motor as the brushless motor rotates. A drive device for driving the motor by changing the counter value of the electric angle counter and switching the energized phase of the brushless motor based on the counter value of the electric angle counter, and each electric angle sensor as the brushless motor rotates. A position sensor that outputs a pulse signal having an edge interval shorter than the edge interval of the pulse signal output from the position sensor, and based on the counter value of the position counter that counts the edge of the pulse signal from the position sensor, the brushless motor In the motor control device that detects the rotation angle,
Every time an edge of a pulse signal output from each electrical angle sensor occurs, the difference (Pi−Pi) between the counter value Pi of the position counter when the current edge occurs and the counter value Pi-1 of the position counter when the previous edge occurs -1) calculating means,
Based on the change of the counter value of the electrical angle counter, it is determined whether the rotation state of the brushless motor is normal rotation, reverse rotation, or normal / reverse rotation inversion, and the brushless motor rotation state is determined. In response, setting means for variably setting a normal value which is a normal value of the difference (Pi-Pi-1);
First correction means for setting a deviation amount of the difference (Pi−Pi−1) with respect to the normal value as a first correction value, and adding a correction corresponding to the first correction value to the counter value of the position counter;
When an edge of the pulse signal output from each electrical angle sensor is generated, a second value for invalidating the correction by the first correction means when the counter value of the electrical angle counter shows a change that is not normally possible. Second correction means for setting a correction value for the second correction value and adding a correction for the second correction value to the counter value of the position counter;
A motor control device comprising: The second correction means obtains a value obtained by inverting the sign of the first correction value that affects the deviation of the counter value of the position counter from the value corresponding to the actual rotation angle of the brushless motor. The motor control device according to claim 1, wherein the motor control device is set as a correction value. When the number of edges of the pulse signal output from the position sensor is “n” between the edges of the pulse signal output from each of the electrical angle sensors, the setting means sets the previous edge from the electrical angle sensor. It is determined that the brushless motor is rotating forward based on the fact that the counter value of the electrical angle counter shows a change in the motor forward rotation direction both at the time of occurrence and at the occurrence of the current edge, and the normal value is set to “n”. And the counter value of the brushless motor is changed based on the fact that the counter value of the electric angle counter indicates a change in the reverse direction of the motor both when the previous edge is generated from the electric angle sensor and when the current edge is generated. The normal value is set to “−n” by judging that the motor is rotating, and the counter of the electrical angle counter at the time of the previous edge generation and the current edge generation from the electrical angle sensor The normal value is set to “0” by determining that the brushless motor is in the reverse rotation inversion based on the difference between the change in the motor forward rotation direction and the change in the motor reverse rotation direction. Is what
The second correction means sets the second correction value to “n” when the counter value of the electric angle counter indicates a change that is not possible in the normal motor rotation direction, and the electric angle counter The motor control device according to claim 1, wherein the second correction value is set to “−n” when the counter value indicates a change that is not possible in the reverse direction of the motor. When the brushless motor is rotating forward, the electrical angle counter uses each successive integer value within the range of “0” to “m” as a counter value in the forward direction according to the output pattern of the pulse signal from each electrical angle sensor. When applying the reverse rotation of the brushless motor, each successive integer value within the range of “0” to “m” is applied as a counter value in the reverse direction according to the output pattern of the pulse signal from each electrical angle sensor. ,
The second correction means determines that the counter value indicates a change that is not normally possible in the forward motor rotation direction based on a change in the counter value of the electrical angle counter by skipping an integer value in the forward direction. The counter value of the electrical angle counter is determined to have changed in the reverse direction of the motor based on the fact that the counter value has changed by skipping an integer value in the reverse direction. Motor control device. The motor control device according to any one of claims 1 to 4, wherein the brushless motor is used to drive a variable valve lift mechanism that varies a valve characteristic of an engine valve of an internal combustion engine.

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