JP2012211807A - Rotation angle calculation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that, when a rotation angle φ is calculated as the operation amount for feed-back controlling an error correlation amount ε to be zero, the hunting phenomenon of the rotation angle φ may occur by the feed-back control, which creates the possibility that a Z signal is mistakenly outputted plural times.SOLUTION: In a proportional gain multiplication part 44, an error correlation amount ε is multiplied by a proportional gain Kp, and in an integral gain multiplication part 46, the error correlation amount ε is multiplied by an integral gain Ki. An output of the integral gain multiplication part 46 is inputted into an integral element 48. The sum of the output of the proportional gain multiplication part 44 and the integral element 48 is the rotation angle φ. When the rotation angle φ becomes around a reference angle θ0 corresponding to a Z signal, the proportional gain Kp and the integral gain Ki are reduced.

Description

  The present invention calculates the rotation angle of the rotating body based on the output signal of the detecting means for detecting the state of the rotating body, and specifies the timing at which the rotation angle of the rotating body becomes the reference angle. The present invention relates to a rotation angle calculation device to be used.

  This type of rotation angle calculation device calculates an error correlation amount sin (θ−φ) corresponding to the difference between the true electrical angle θ and the calculated rotation angle φ based on the output signal of the resolver, and sets this to zero. In order to provide feedback control, a device that manipulates the rotation angle φ has also been proposed (Patent Document 1, paragraph “0021”).

  Further, as a rotation angle calculation device, a device that outputs a reference signal that notifies the fact that the rotation angle calculated based on the output signal of the resolver becomes the reference angle is also well known. This reference signal is used for calculating the rotation speed and correcting the error of the rotation angle.

JP 2006-292434 A

  By the way, when the rotation angle φ calculated as described above is used as an operation amount for performing feedback control so that the error correlation amount is zero, a phenomenon in which the rotation angle φ is hunted by feedback control may occur. When the rotation angle φ vibrates between the advance side and the retard side of the reference angle, the reference signal is output a plurality of times. In this case, problems such as a decrease in the calculation accuracy of the rotational speed and the inability to appropriately perform error correction may occur.

  The present invention has been made in the process of solving the above-mentioned problems, the purpose of which is to calculate the rotation angle of the rotating body based on the output signal of the detection means for detecting the state of the rotating body, the rotation angle, An object of the present invention is to provide a new rotation angle calculation device that is used by a specifying unit that specifies the timing at which the rotation angle of the rotating body becomes a reference angle.

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

  According to the first aspect of the present invention, the rotation angle of the rotating body is calculated based on the output signal of the detecting means for detecting the state of the rotating body, and the rotation angle is determined based on the timing at which the rotation angle of the rotating body becomes the reference angle. In the rotation angle calculation device used by the specifying means for specifying, an angle correlation amount calculating means for calculating an angle correlation amount having a correlation with the rotation angle of the rotating body based on the output signal of the detection means, and the angle correlation amount An angle calculation unit that calculates the rotation angle based on an operation amount for feedback control to a target value and outputs the rotation angle to the specifying unit, and a hunting phenomenon of the calculated rotation angle due to the feedback control occurs. The avoidance means for avoiding that the timing interval specified by the specifying means is shorter than the actual timing interval accompanying the rotation of the rotating body. , Characterized in that it comprises a.

  In the above invention, by providing the avoiding means, it is possible to avoid a situation where the reference angle is erroneously specified a plurality of times due to the hunting phenomenon.

  According to a second aspect of the present invention, in the first aspect of the invention, the detection means is a rotation angle detection means for detecting a rotation angle of the rotating body.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the avoiding means causes the calculated rotation angle to vibrate between the advance side and the retard side of the reference angle by the feedback control. It is provided with the suppression means which suppresses.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the suppressing means includes a gain reducing means for reducing the gain of the feedback control in a predetermined region including the reference angle.

  When the gain of the feedback control is increased, the responsiveness of the feedback control can be improved, but a hunting phenomenon is likely to occur. In the above invention, in view of this point, the vibration of the rotation angle in the predetermined region can be suitably suppressed by reducing the feedback control gain in the predetermined region.

  The invention described in claim 5 is the invention described in claim 4, wherein the gain reducing means variably sets the gain according to a rotation angle of the rotating body in the predetermined region.

  In the said invention, the said gain in a predetermined area | region is variably set according to a rotation angle, The setting which makes compatible reduction of a vibration and suppression of the fall of the calculation precision of a rotation angle becomes easy.

  A sixth aspect of the present invention is the method according to any one of the third to fifth aspects, wherein the suppression means is an operation amount for the feedback control in a predetermined region on the retard side with respect to the reference angle. A changing means for forcibly changing the rotation angle is provided.

  In the above invention, the rotation angle calculated by the angle calculating means is forcibly changed by the changing means. Here, when the angle is changed to the advance side, the rotation angle calculated by the feedback control is changed to the retard side. However, if the most retarded angle position is set to be on the more advanced side than the reference position during the period in which the rotation angle is changed to the retarded side, the situation in which the reference angle is erroneously specified multiple times can be avoided. Can do. Further, when changing to the retard side, the rate of change of the rotation angle calculated by feedback control to the advance side increases. Then, the calculated rotation angle crosses the reference angle, and then hunting that fluctuates toward the retard angle side and the advance angle side may occur. However, the region where the hunting occurs can be set to the advance angle side with respect to the reference angle. Then, it is possible to avoid a situation where the reference angle is erroneously specified a plurality of times.

  The invention according to claim 7 is the invention according to claim 6, wherein the changing means variably sets the forcible change amount according to a rotation angle of the rotating body.

  In the above-described invention, the change amount in the predetermined region is variably set according to the rotation angle, thereby facilitating the setting that achieves both the reduction of the vibration in the predetermined region and the suppression of the decrease in the calculation accuracy of the rotation angle.

  The invention according to claim 8 is the invention according to any one of claims 3 to 7, wherein the suppression means includes a predetermined range including the reference angle and a region from the reference angle to an angle advanced by a specified amount. And a prohibiting unit that prohibits the calculated rotation angle from changing to the retard side in the region.

  In the above invention, by providing the prohibiting means, it is possible to avoid the rotation angle oscillating between the advance side and the retard side in the predetermined region.

  The invention according to claim 9 is the invention according to claim 8, wherein the prohibiting means specifies the advance side based on a change in a rotation angle before reaching the reference angle.

  A tenth aspect of the present invention is the invention according to any one of the third to ninth aspects, wherein the suppressing means limits the change speed of the calculated rotation angle in a predetermined region including the reference angle. A change speed limiting means is provided.

  The situation where the rotation angle calculated by the angle calculation means vibrates due to the feedback control is likely to occur when the change speed of the calculated rotation angle is excessively larger than the rotation speed. In the above invention, in view of this point, the vibration of the rotation angle is suppressed by limiting the calculated change speed of the rotation angle.

  An eleventh aspect of the invention is characterized in that, in the tenth aspect of the invention, the change speed limiting means guards the rotation angle output from the angle calculation means.

  According to a twelfth aspect of the present invention, in the invention according to the tenth aspect, the change speed limiting means low-pass filters the rotation angle immediately before the angle calculation means outputs in the predetermined area.

  A thirteenth aspect of the invention is the invention according to any one of the fourth to twelfth aspects, wherein the suppression means is calculated by the rotation angle information of the rotating body obtained from other than the detection means, and the angle calculation means. The predetermined area is grasped on the basis of either the rotation angle to be performed or the elapsed time from the reference angle.

  The invention according to a fourteenth aspect is the invention according to any one of the first to thirteenth aspects, wherein the avoiding means is configured such that the angle calculating means is at an interval shorter than an actual interval associated with the rotation of the rotating body. In the case of calculating the reference angle, there is provided invalidating means for invalidating a result of the calculation for the specifying means.

  In the above invention, even if the angle calculation means mistakenly calculates a plurality of reference angles, the specification means mistakenly specifies a plurality of times so that the calculation result is not reflected in the specification means. Can be avoided.

  According to a fifteenth aspect of the present invention, in the invention according to the fourteenth aspect, the invalidating unit specifies again the timing at which the reference angle is set over a predetermined period after the timing at which the reference angle is specified by the specifying unit. Is prohibited.

1 is a system configuration diagram according to a first embodiment. FIG. The flowchart which shows the procedure of the switching process of the feedback control gain concerning the embodiment. The flowchart which shows the procedure of the switching process of the feedback control gain concerning 2nd Embodiment. The flowchart which shows the procedure of the pre-processing for recognition of the predetermined area | region concerning 3rd Embodiment. The flowchart which shows the procedure of the switching process of the feedback control gain concerning the embodiment. The time chart which shows the variable setting method of the feedback gain concerning 4th Embodiment. The flowchart which shows the procedure of the change process of the rotation angle concerning 5th Embodiment. The time chart which shows the change process aspect of the rotation angle concerning the embodiment. The figure which shows the change method of the rotation angle concerning 6th Embodiment. The flowchart which shows the procedure of the prohibition process of the change to the retard side of the rotation angle concerning 7th Embodiment. The time chart which shows the prohibition process aspect of the change to the retard side of the rotation angle concerning the embodiment. The flowchart which shows the procedure of the reduction process of the change speed of the rotation angle concerning 8th Embodiment. The flowchart which shows the procedure of the reduction process of the change speed of the rotation angle concerning 9th Embodiment. 14 is a flowchart showing a procedure of Z signal output inhibition processing according to the tenth embodiment.

<First Embodiment>
Hereinafter, a first embodiment in which a rotation angle calculation device according to the present invention is applied to a rotation angle calculation device of an in-vehicle main machine will be described with reference to the drawings.

  FIG. 1 shows a system configuration according to the present embodiment.

  The illustrated motor generator 10 is an in-vehicle main machine, and a rotating shaft 10a is mechanically connected to driving wheels (not shown). The motor generator 10 is connected to an inverter INV, and an AC voltage is applied by the inverter INV.

  The rotation shaft 10 a of the motor generator 10 is mechanically coupled to an excitation coil 22 that constitutes the resolver 20. An AC signal (excitation signal Sc) having an angular velocity ω is applied from the oscillator 24 to the excitation coil 22. Thereby, the magnetic flux generated in the exciting coil 22 periodically changes. The resolver 20 further includes detection coils 26 and 28. The magnetic fluxes interlinking the detection coils 26 and 28 are shifted in phase from each other by “π / 2” depending on the setting of the arrangement of the detection coils 26 and 28. In particular, in the present embodiment, a voltage obtained by amplitude-modulating the excitation signal Sc by the sine function sin θ is generated in the detection coil 26, and a voltage obtained by amplitude-modulating the excitation signal Sc by the cosine function cos θ is generated in the detection coil 28. Is set to The output voltages of these detection coils 26 and 28 are converted into digital signals SIN and COS by analog-digital converters 30 and 32, respectively.

  On the other hand, the cosine function calculation unit 36 calculates a cosine function cos φ having the calculated value (rotation angle φ) of the rotation angle of the motor generator 10 as an independent variable. Then, the multiplication unit 34 multiplies the digital signal SIN by a cosine function cosφ as a digital signal. Further, the sine function calculation unit 40 calculates a sine function sin φ having the rotation angle φ as an independent variable. Then, the multiplication unit 38 multiplies the digital signal COS by a sine function sin φ as a digital signal.

  The subtractor 42 calculates the error correlation amount ε by subtracting the output of the multiplier 38 from the output of the multiplier 34. This is a digital value proportional to “sinωt · sin (θ−φ)”. That is, the output voltage of the detection coil 26 is a value proportional to “sin ωt · sin θ”, and the output voltage of the detection coil 28 is a value proportional to “sin ωt · cos θ”. If the proportionality constant is ignored, it is calculated as follows using the addition theorem.

sinωt · sinθ · cosφ + sinωt · cosθ · sinφ
= Sinω ・ sin (θ－φ)
When the error correlation amount ε is zero, the rotation angle θ of the motor generator 10 matches the calculated rotation angle φ.

  The proportional gain multiplication unit 44 multiplies the error correlation amount ε by the proportional gain Kp. The integral gain multiplication unit 46 multiplies the error correlation amount ε by the integral gain Ki. The adder 50 calculates the rotation angle φ by adding the output of the proportional gain multiplier 44 and the output of the integration element 48 that receives the output of the integral gain multiplier 46 as an input. The rotation angle φ is input to the cosine function calculation unit 36 and the sine function calculation unit 40. As a result, the rotation angle φ becomes an operation amount for feedback control of the error correlation amount ε to zero.

  The angle information output unit 52 generates a pair of periodic signals, an A phase signal and a B phase signal, and a Z signal based on the rotation angle φ, and outputs them to the control unit 54. Here, the A-phase signal and the B-phase signal are signals that express the rotation direction by the phase difference and the rotation angle by the pulse. The Z signal is for indicating a specific rotation angle (reference angle θ0) within one cycle of the rotation angle θ.

  The control unit 54 generates an operation signal for the inverter INV based on the current flowing through the motor generator 10 detected by the current sensor 12 and the signal output from the angle information output unit 52 and outputs the operation signal to the inverter INV. Thereby, the control amount (torque etc.) of the motor generator 10 is controlled. At this time, the control unit 54 calculates the rotational speed of the motor generator 10 based on the time interval at which the Z signal is input, and uses this to control the control amount. Further, based on the time interval at which the Z signal is input, a process for correcting the rotation angle detection error by the resolver 20 is performed. As this correction process, a known technique may be used.

  By the way, since the rotation angle φ is calculated by feedback control, even if the rotation direction of the motor generator 10 is constant, there is a possibility that the rotation angle φ vibrates toward the advance side and the retard side. Here, when the rotation angle φ vibrates between the advance side and the retard side of the reference angle θ0, the Z signal may be erroneously output a plurality of times within a short time. In this case, there is a risk of inconvenience such as a decrease in the calculation accuracy of the rotational speed.

  Therefore, in the present embodiment, such a situation is suppressed by switching processing of gain (proportional gain Kp, integral gain Ki) of feedback control.

  FIG. 2 shows the procedure of the switching process. This process is repeatedly executed, for example, at a predetermined cycle by hardware means including the proportional gain multiplication unit 44, the integral gain multiplication unit 46, and the like.

  In this series of processing, first, in step S10, the calculated rotation angle φ is between an angle delayed by a specified amount Δ and an angle advanced by a specified amount Δ with respect to the reference angle θ0 (predetermined region: θ0−). It is determined whether or not Δ ≦ φ ≦ θ0 + Δ). If an affirmative determination is made in step S10, in step S12, the proportional gain Kp and the integral gain Ki are set to the vibration suppression gains KpL and KiL, respectively. On the other hand, when a negative determination is made in step S10, in step S14, the proportional gain Kp and the integral gain Ki are set to the high response gains KpH and KiH, respectively. Here, the vibration suppression gains KpL and KiL are set to values smaller than the high response gains KpH and KiH. This is because control hunting is more likely to occur as the proportional gain Kp and the integral gain Ki are larger. Therefore, the vibration suppression gains KpL and KiL are used in the vicinity of the reference angle θ0 in order to suppress the vibration of the rotation angle φ in the vicinity of the reference angle θ0. The prescribed amount Δ is set based on a lower limit value that is assumed to cause the rotation angle φ to oscillate across the reference angle θ0 when the high response gains KpH and HiH are used.

Incidentally, when the processes in steps S12 and S14 are completed, this series of processes is temporarily terminated.
<Second Embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 3 shows the procedure of the switching process according to this embodiment. This process is repeatedly executed, for example, at a predetermined cycle by hardware means including the proportional gain multiplication unit 44, the integral gain multiplication unit 46, and the like. In FIG. 3, processes corresponding to the processes shown in FIG. 2 are given the same step numbers for convenience.

  In this series of processing, first, in step S20, an alternative angle θa for the rotation angle θ of the motor generator 10 that is not based on the output signal of the resolver 20 is acquired. For example, in the case where the engine crankshaft is mechanically coupled to the rotation shaft 10a of the motor generator 10, the detection value of the sensor for detecting the rotation angle of the engine crankshaft or a value corresponding thereto is used. Good. Alternatively, the rotation angle estimated based on the electrical state quantity of the motor generator 10 may be used.

In the subsequent step S10a, it is determined whether or not the alternative angle θa is within a predetermined region “θ0−Δ ≦ θa ≦ θ0 + Δ” including the reference angle θ0.
<Third Embodiment>
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 4 shows a processing procedure for recognizing a predetermined area used for the switching process. This process is repeatedly executed, for example, at a predetermined cycle by hardware means capable of acquiring the output signal of the adder 50. FIG. 4 exemplifies a process when the rotation angle φ increases with the rotation of the motor generator 10.

  In this series of processes, first, in step S22, it is determined whether or not the calculated rotation angle φ is at a timing across the reference angle θ0. In FIG. 4, it is assumed that the reference angle θ0 is an angle between zero and 2π. In this case, when the previous rotation angle φ is smaller than the reference angle θ0 and the current rotation angle φ is equal to or greater than the reference angle θ0, it can be determined that the timing is over the reference angle θ0.

  When an affirmative determination is made in step S22, a time counting operation is performed in step S24 by the timer T that times the time from the timing across the reference angle θ0. In the subsequent step S24, the process waits until the timer T becomes equal to or greater than the threshold time TL. Here, the threshold time TL is set to a time estimated to be required until the rotation angle φ enters the predetermined region “θ0−Δ ≦ φ ≦ θ0 + Δ”. The threshold time TL is actually calculated based on the rotation speed of the motor generator 10. The rotational speed may be calculated as an average value of instantaneous change speeds of the rotational angle φ.

  When an affirmative determination is made in step S26, in step S28, the timer T is initialized, and the timer TT that measures the time since entering the predetermined area is started. In addition, when the process of step S28 is completed, this series of processes is once complete | finished.

  FIG. 5 shows the procedure of the switching process according to the present embodiment. This process is repeatedly executed, for example, at a predetermined cycle by hardware means including the proportional gain multiplication unit 44, the integral gain multiplication unit 46, and the like. In FIG. 5, processes corresponding to the processes shown in FIG. 2 are given the same step numbers for convenience.

  In this series of processing, first, in step S30, it is determined whether or not the timer TT is greater than 0 and less than or equal to a specified time Tth. This process is for determining whether or not the rotation angle φ is in a predetermined region “θ0−Δ ≦ φ ≦ θ0 + Δ”. Here, the specified time Tth is set to a time at which the rotation angle φ is predicted to stay in a predetermined region. The specified time Tth is actually calculated based on the rotational speed of the motor generator 10.

If a positive determination is made in step S30, the process proceeds to step S12. If a negative determination is made in step S30, the timer TT is initialized in step S32, and then the process proceeds to step S14.
<Fourth Embodiment>
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

FIG. 6 shows a variable setting method for the proportional gain Kp and the integral gain Ki according to the present embodiment. As shown in the figure, in the present embodiment, when both the proportional gain Kp and the integral gain Ki are reduced in the vicinity of the reference angle θ0, the reduction amount is variably set according to the rotation angle φ. As a result, the degree of freedom in design for achieving both the reduction of the vibration at the rotation angle φ in the vicinity of the reference angle θ0 and the reduction in the accuracy of the rotation angle φ is improved.
<Fifth Embodiment>
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  In the present embodiment, by forcibly changing the rotation angle φ in the vicinity of the reference angle θ0, the rotation angle φ is prevented from vibrating in the vicinity of the reference angle θ0.

  FIG. 7 shows the procedure of the forcible change process. This process is repeatedly executed, for example, at a predetermined cycle by hardware means capable of acquiring the output signal of the adding unit 50. Note that FIG. 7 illustrates processing when the rotation angle φ increases with the rotation of the motor generator 10.

  In this series of processes, first, in step S34, it is determined whether or not the calculated rotation angle φ is at a timing straddling an angle (θ0−Δ) delayed by a specified amount Δ from the reference angle θ0. In FIG. 7, it is assumed that this angle (θ0−Δ) is an angle between zero and 2π. In this case, when the previous rotation angle φ is smaller than the angle (θ0−Δ) and the current rotation angle φ is equal to or larger than the angle (θ0−Δ), the angle (θ0−Δ) is straddled. It can be determined that it is time.

  When an affirmative determination is made in step S34, the rotation angle φ is forcibly advanced in step S36 by adding a specified amount Skip to the rotation angle φ. Here, the specified amount Skip is desirably set to an upper limit (for example, 3 °) or less that can be generated as an error in the detection value of the resolver 20. Alternatively, it may be set to be equal to or lower than the upper limit value of the rotation angle error that is assumed not to reach an unacceptable level of controllability of the motor generator 10.

  As a result, as shown in FIG. 8, it is possible to avoid a situation in which the rotation angle φ vibrates between the advance side and the retard side of the reference angle θ0. FIG. 8 shows an example in which the reference angle θ0 is jumped over the rotation angle φ by changing the rotation angle φ by a specified amount Skip at time t1 immediately before the reference angle θ0. In this case, since the rotation angle φ is on the more advanced side than the actual rotation angle θ, the rotation angle φ is changed to the retard side by feedback control after the change of the specified amount Skip, but the hunting phenomenon associated with this Occurs on the advance side of the reference angle θ0. For this reason, it is possible to avoid a situation in which the rotation angle φ vibrates between the advance side and the retard side of the reference angle θ0.

  In the present embodiment, the specified amount Skip is variably set according to the rotation speed of the rotating shaft 10a. This is because an appropriate amount changes in order to avoid the rotation angle φ oscillating between the advance side and the retard side of the reference angle θ0 according to the rotation speed of the rotary shaft 10a. The rotation speed may be calculated as an average value of instantaneous change speeds of the rotation angle φ.

When the process of step S36 of FIG. 7 is completed or when a negative determination is made in step S34, this series of processes is temporarily ended.
<Sixth Embodiment>
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the fifth embodiment.

  In the present embodiment, the specified amount Skip for changing the rotation angle φ is variably set according to the rotation angle φ. As shown in FIG. 9, this can be performed based on a map that defines the relationship between the rotation angle φ and the specified amount Skip.

  According to this map, for example, when the rotation angle φ is changed only once by the specified amount Skip in the vicinity of the reference angle θ0, a more appropriate specified amount Skip corresponding to the rotation angle φ at the change timing can be set. Alternatively, the rotation angle φ may be changed a plurality of times in the vicinity of the reference angle θ0 in accordance with the prescribed amount Skip calculated for each map. In this case, the rotation angle φ as an input parameter of the map may use a value after the change, but may use a rotation angle estimated according to the value before the change and the rotation speed of the rotary shaft 10a. .

As a result, it is possible to suppress the rotation angle φ from oscillating between the advance side and the retard side of the reference angle θ0, and to suppress a decrease in accuracy of the rotation angle φ due to the change by the specified amount Skip. The degree of freedom of setting for achieving compatibility is improved.
<Seventh Embodiment>
Hereinafter, the seventh embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, immediately after the rotation angle φ passes the reference angle θ0, this is prohibited when the change direction is to be reversed by feedback control.

  FIG. 10 shows the procedure of the prohibition process. This process is repeatedly executed, for example, at a predetermined cycle by hardware means capable of acquiring the output signal of the adding unit 50.

  In this series of processing, first, in step S40, it is determined whether or not the angle is near the reference angle θ0. If a negative determination is made in step S40, the rotation direction is determined in step S41.

  On the other hand, when an affirmative determination is made in step S40, it is determined in step S42 whether or not the rotation direction determined in step S41 is normal rotation. Here, the normal rotation means that the rotation angle φ is increasing. According to the determination in step S42, it is possible to specify the sign of the change in the advance angle side of the rotation angle φ (change in the actual rotation direction). In subsequent steps S43 and S44, it is determined whether or not the rotation angle φ is the reference angle θ0 or an advance side with respect to the reference angle θ0 and the advance amount is equal to or less than a specified amount Δ. If an affirmative determination is made in steps S43 and S44, in step S45 and S46, the rotation angle φ (n) calculated this time changes to the advance side with respect to the previous rotation angle φ (n−1). Determine whether or not. If a negative determination is made in steps S45 and S46, the rotation angle φ (n) calculated this time is set as the previous rotation angle φ (n−1) in step S47.

  When the processes of steps S47 and S41 are completed, when an affirmative determination is made at steps S45 and S46, and further when a negative determination is made at steps S43 and S44, the rotation angle calculated this time at step S48. The variable n for specifying φ (n) is changed to “n−1”, and this series of processes is temporarily terminated.

  FIG. 11 exemplifies the prohibition process in forward rotation.

As shown in the drawing, after the rotation angle φ has passed the reference angle θ0, it starts to change to the retard side after a while, but when it reaches a value advanced by a specified amount Δ from the reference angle θ0, it is further exceeded. Changes to the retarded angle side are prohibited. Thereby, the situation where the reference angle θ0 is erroneously specified a plurality of times can be avoided.
<Eighth Embodiment>
Hereinafter, the eighth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, the instantaneous change speed of the rotation angle φ is limited.

  FIG. 12 shows the procedure of the restriction process according to this embodiment. This process is repeatedly executed, for example, at a predetermined cycle by hardware means capable of acquiring the output signal of the adding unit 50.

  In this series of processing, first, in step S50, is the absolute value of the difference between the rotation angle φ (n−1) calculated last time and the rotation angle φ (n−1) calculated this time larger than a specified value Δφ? Judge whether or not. In this process, it is determined whether or not the instantaneous change of the rotation angle φ is excessively larger than that assumed from the rotation speed of the rotary shaft 10a, and thus hunting is likely to occur due to feedback control. belongs to. Here, the prescribed value Δφ is variably set according to the rotational speed of the rotating shaft 10a. In this embodiment, an average value of instantaneous change speeds of the rotation angle φ is used as the rotation speed.

If an affirmative determination is made in step S50, in step S52, the amount of change of the currently calculated rotation angle φ (n) with respect to the previously calculated rotation angle φ (n−1) is limited to a specified value Δφ. When the process of step S52 is completed or when a negative determination is made in step S50, the variable n for specifying the rotation angle φ (n) calculated this time is changed to “n−1” in step S54. This series of processes is once terminated.
<Ninth Embodiment>
Hereinafter, the ninth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 13 shows a procedure for limiting the instantaneous change speed of the rotation angle φ according to this embodiment. This process is repeatedly executed, for example, at a predetermined cycle by hardware means capable of acquiring the output signal of the adding unit 50.

  In this series of processing, first, in step S60, it is determined whether or not the calculated rotation angle φ is in a predetermined region (θ0−Δ ≦ φ ≦ θ0 + Δ) including the reference angle θ0. If an affirmative determination is made in step S60, the rotation angle φ is low-pass filtered in step S62.

When the process of step S62 is completed or when a negative determination is made in step S60, this series of processes is temporarily terminated.
<Tenth Embodiment>
Hereinafter, the tenth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, instead of allowing the rotation angle φ as the feedback operation amount to vibrate in the vicinity of the reference angle θ0, the rotation angle over a predetermined period after once specifying the timing at which the rotation angle φ becomes the reference angle θ0. The process of specifying the timing when φ becomes the reference angle θ0 is prohibited.

  FIG. 14 shows the procedure of the specifying process according to the present embodiment. This process is repeatedly executed, for example, at a predetermined cycle by hardware means capable of acquiring the output signal of the adding unit 50. Note that FIG. 14 illustrates processing when the rotation direction of the rotation shaft 10a is on the side where the rotation angle φ is increased.

  In this series of processes, first, in step S70, it is determined whether or not the rotation angle φ crosses the reference angle θ0. If an affirmative determination is made in step S70, the Z signal is output to the control unit 54 shown in FIG. 1 in step S72. In the subsequent step S74, the timer T that measures the time from when the Z signal is output is counted. In a succeeding step S76, it is determined whether or not the timer T is equal to or shorter than a specified time Tth. This process is for determining whether or not it is in a period during which the second output of the Z signal is prohibited. Here, the specified time Tth is a time when it is assumed that the reference angle φ is not erroneously calculated again due to the hunting phenomenon caused by the feedback control, and is required until the reference angle θ0 actually appears again. The time is set shorter than the time. The specified time Tth is variably set according to the rotation speed of the rotating shaft 10a. In the present embodiment, this rotational speed is calculated by an average value of instantaneous change speeds of the rotational angle φ.

  If an affirmative determination is made in step S76, output of the Z signal is prohibited in step S78, and the process returns to step S74. On the other hand, if a negative determination is made in step S76, the prohibition is canceled, and the timer T is initialized in step S80.

When the process of step S80 is completed or when a negative determination is made in step S70, this series of processes is temporarily terminated.
<Other embodiments>
Each of the above embodiments may be modified as follows.

"About gain reduction means"
The proportional gain Kp, the integral gain Ki, etc. are not limited to being variable. For example, in a predetermined region “θ0−Δ ≦ φ ≦ θ0 + Δ”, “π / 4” is added to the rotation angle φ, and the target value of the angular correlation amount as the sum of the outputs of the proportional element and the integral element is “ It may be 1 / √2 ”. This is because the rate of change of the sine function is smaller at “π / 4” than at “0 °”.

  Further, an equivalent effect may be obtained by locally shifting a value calculated in at least one of the cosine function calculation unit 36 and the sine function calculation unit 40 from the cosine function value or the sine function value. That is, for example, when the reference angle θ0 = 0 °, the value calculated by the sine function calculation unit 40 is set so that the absolute value becomes smaller than the actual sine function value in the vicinity of the reference angle θ0. If the rate of change with respect to is moderated, it is equivalent to reducing the gain.

  Furthermore, in the configuration shown in FIG. 1, the proportional gain Kp may be decreased and the integral gain Kp may be increased in the predetermined region “θ0−Δ ≦ φ ≦ θ0 + Δ”. Thereby, since a high frequency response falls, the rapid change of rotation angle (phi) can be suppressed.

  In addition, a signal obtained by multiplying the output signals of the analog-digital converters 30 and 32 by a gain may be output to the multipliers 34 and 32, and the gain may be changed in a predetermined region.

"Change means"
The rotation angle φ is not limited to a value on the advance side, but may be changed to a value on the retard side. Even in this case, if the hunting of the rotation angle φ by the feedback control can occur after passing through the reference angle θ0, the same effect as the fifth embodiment can be obtained.

“Prohibited measures”
The present invention is not limited to specifying the advance side and the retard side based on the changing direction of the rotation angle other than near the reference angle θ0. For example, the advance side and the retard side may be specified based on the sign of the average speed at all rotation angles.

  The sign of the average speed in the predetermined period of the output value of the adder 50 is not limited to the prohibition of the rotation angle φ changing to the retard side only in the predetermined region “θ0−Δ ≦ φ ≦ θ0 + Δ”. Until the rotation is reversed, the rotation angle φ may be prohibited from changing to the retard side.

"Change rate limiting means"
The output of the adder 50 may be subjected to low-pass filter processing in a region other than the predetermined region “θ0−Δ ≦ φ ≦ θ0 + Δ”, and the cut-off frequency may be reduced when the predetermined region is reached.

About invalidation means
The present invention is not limited to that illustrated in the tenth embodiment. For example, after the reference angle θ0 is specified, re-specification of the timing at which the rotation angle φ becomes the reference angle θ0 may be prohibited until the calculated rotation angle φ changes by a predetermined rotation angle.

  Further, for example, when the rotation angle φ calculated by the adding unit 50 becomes a value delayed by a specified amount Δ from the reference angle θ0, the specifying means has an average value of the instantaneous change speed of the rotation angle φ. The rotation angle may be estimated based on the above, and the timing at which φ = θ0 may be estimated. Incidentally, in this case, another estimation process is prohibited until the estimated timing is reached.

"Angle correlation calculation method"
The fact that the error correlation amount (those where the target value is zero) is not necessarily calculated as the angle correlation amount is as described in the “About gain reduction means” column and “About the angle calculation means” column. is there.

"Reference angle"
The rotating body (rotating shaft 10a) is not limited to once per rotation. For example, in the case where the fluctuation cycle of the voltage of the detection coil is 1 / integer of the rotation cycle of the rotating body, the reference angle may be provided once for each fluctuation cycle. In this case, when the specifying unit outputs each reference angle, a rotation angle correction process or the like can be performed based on the reference angle. In particular, when the electrical angle cycle and the fluctuation cycle of the rotating machine are the same, it is easy to calculate the electrical angular velocity from the reference angle interval. A plurality of reference angles may be provided within one cycle of the fluctuation cycle.

About specific means
What is not limited to the one that outputs the Z signal is as described in the column “Regarding Reference Angle”.

  Further, for example, when performing rectangular wave control for switching the switching state once in a half cycle of the electrical angle for each phase, means for specifying the rotation angle of this switching as a reference angle may be used. Even in such a case, it is effective to provide an avoidance means so that the switching timing of the switching state is not erroneously specified a plurality of times in a short time. In this case, the specifying unit itself may be mounted on the control unit 54 without being mounted on the angle information output unit 52. At this time, for example, when the avoidance unit is configured by a gain reduction unit, a signal designating a predetermined region near the reference angle θ0 may be output from the control unit 54 side to the angle information output unit 52. Thereby, based on the rotation angle φ output from the angle information output unit 52, the rectangular wave control can be performed while the reference angle θ0 is specified by the specifying unit in the control unit 54. However, in the case where the angle information output unit 52 and the control unit 54 are separate hardware units connected by a communicable signal line, the control unit 54 may include a specifying unit on the angle information output unit 52 side. This is desirable from the viewpoint of reducing the calculation load when the control amount of the motor generator 10 is controlled.

"Angle calculation means"
The rotation angle θ is not limited to the calculation of the rotation angle θ as the sum of the proportional elements of the difference between the angle correlation amount and the target value and the outputs of the integral elements. For example, the rotation angle θ may be calculated as the sum of a proportional element, an integral element, and a derivative element.

  Further, the feedback operation amount is not limited to the direct rotation angle φ. For example, the feedback manipulated variable is used when calculating the final rotation angle φ using the rotation angle φ1 calculated based on the inverse trigonometric function of the output values of the analog-digital converters 30 and 32 shown in FIG. It may be a thing. Specifically, for example, the previous value of the final rotation angle φ is set as an angle correlation amount, and the operation amount for performing feedback control to the current rotation angle φ1 that is the target value is obtained by differential calculation of the rotation angle φ1. The current rotation angle φ may be calculated by correcting a value obtained by performing an integral operation after low-pass filter processing is performed on the calculated rotation speed.

"Rotation angle detection means"
As a resolver, the voltage of the detection coil when the magnetic flux generated in the excitation coil rotating integrally with the rotor is linked with the detection coil provided as the stator is output as a physical quantity having a correlation with the rotation angle. Not limited to things. For example, both the excitation coil and the detection coil are provided on one of the rotor and the stator, and the other is made of a magnetic material, and between the excitation coil and the detection coil as the rotor rotates. It may be set so that the mutual inductance varies.

  Moreover, not only a resolver but an encoder etc. may be sufficient. Even in this case, if the rotation angle θ is calculated as an operation amount for performing feedback control of the angle correlation amount calculated based on the output signal to the target value, hunting may occur in association with the feedback control. . For this reason, even in such a case, it is effective to provide avoidance means when the timing to be the reference angle is specified and used.

About detection means
It is not limited to the rotation angle detection means. For example, in a system that superimposes a voltage signal having a frequency higher than the electrical angular frequency on the d-axis component of the output voltage of the DC / AC converter circuit, a high-frequency current signal that actually propagates through the rotating machine as the high-frequency voltage signal is superimposed is detected. It may be a means. In this case, since the deviation of the high-frequency current signal from the d-axis direction corresponds to an error, for example, the cross product value of the high-frequency voltage signal and the high-frequency current signal is used as an angle correlation amount (error correlation amount), and this is feedback-controlled to zero. It is possible to estimate the rotation angle θ by manipulating the rotation angle θ as an estimation target. Even in this case, it is effective to provide avoidance means when the timing to be the reference angle is specified and used.

  DESCRIPTION OF SYMBOLS 20 ... Resolver, 44 ... Proportional gain Kp, 46 ... Integration gain, 48 ... Integration element, 50 ... Adder, 52 ... Angle information output part.

Claims (15)

Rotation that calculates the rotation angle of the rotating body based on the output signal of the detecting means for detecting the state of the rotating body, and uses the rotation angle for specifying means for specifying the timing at which the rotation angle of the rotating body becomes a reference angle In the angle calculation device,
An angle correlation amount calculating means for calculating an angle correlation amount having a correlation with a rotation angle of the rotating body based on an output signal of the detection means;
Angle calculation means for calculating the rotation angle based on an operation amount for feedback control of the angle correlation amount to a target value, and outputting the rotation angle to the specifying means;
Due to the hunting phenomenon of the calculated rotation angle due to the feedback control, the timing interval specified by the specifying means is shorter than the actual timing interval accompanying the rotation of the rotating body. Avoidance means to avoid
A rotation angle calculation device comprising:   The rotation angle calculation device according to claim 1, wherein the detection unit is a rotation angle detection unit that detects a rotation angle of the rotating body.   The said avoiding means is provided with the suppression means which suppresses that the calculated rotation angle vibrates between the advance side and the retard side of the reference angle by the feedback control. Rotation angle calculation device.   The rotation angle calculation device according to claim 3, wherein the suppression unit includes a gain reduction unit that reduces the gain of the feedback control in a predetermined region including the reference angle.   The rotation angle calculation device according to claim 4, wherein the gain reduction means variably sets the gain according to a rotation angle of the rotating body in the predetermined region.   The said suppression means is provided with the change means which changes the rotation angle as an operation amount for the said feedback control compulsorily in the predetermined area | region of the retard angle side rather than the said reference angle. The rotation angle calculation device according to any one of the above.   The rotation angle calculation device according to claim 6, wherein the changing unit variably sets the forcible change amount according to a rotation angle of the rotating body.   The suppressing means includes a prohibiting means for prohibiting the calculated rotation angle from changing to the retard side in a predetermined region including the reference angle and a region from the reference angle to an angle advanced by a specified amount. The rotation angle calculation device according to claim 3, wherein the rotation angle calculation device is a rotation angle calculation device.   9. The rotation angle calculation apparatus according to claim 8, wherein the prohibiting means specifies the advance angle side based on a change in rotation angle before reaching the reference angle.   The said suppression means is provided with the change speed limiting means which restrict | limits the change speed of the said calculated rotation angle in the predetermined area | region containing the said reference angle, The any one of Claims 3-9 characterized by the above-mentioned. Rotation angle calculation device.   The rotation angle calculation device according to claim 10, wherein the change speed limiting unit guards a rotation angle output from the angle calculation unit.   The rotation angle calculation device according to claim 10, wherein the change speed limiting unit performs low-pass filter processing on a rotation angle immediately before the angle calculation unit outputs in the predetermined region.   The suppression means grasps the predetermined region based on any one of rotation angle information of the rotating body obtained from other than the detection means, a rotation angle calculated by the angle calculation means, and an elapsed time from the reference angle. The rotation angle calculation device according to claim 4, wherein the rotation angle calculation device is a rotation angle calculation device.   The avoiding means includes invalidating means for invalidating a result of the calculation for the specifying means when the angle calculating means calculates a reference angle at an interval shorter than an actual interval associated with the rotation of the rotating body. The rotation angle calculation device according to claim 1, comprising: a rotation angle calculation device according to claim 1.   The rotation angle calculation according to claim 14, wherein the invalidating unit prohibits re-specification of the timing that becomes the reference angle over a predetermined period after the timing that becomes the reference angle is specified by the specifying unit. apparatus.

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