JP2005024493A - Abnormality detector for resolver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an abnormality detector for a resolver capable of detecting abnormality of the resolver, by simple circuit constitution. <P>SOLUTION: An excitation signal f(t) comprising a prescribed frequency is impressed from an excitation signal output circuit 9 to the resolver 1, two output signals (t)sinθ, (t)cosθ amplitude-modulated in response to an axial angle θ (electric angle) of the resolver 1 are output, and a sinθ and a cosθ are found by synchronization-detecting the two signals with the excitation signal f(t). The sinθ and the cosθ are input respectively in a comparator 15, and levels of the sinθ and the cosθ are determined with respect to a prescribed threshold value 16, so as to be converted respectively into a sinθ side rectangular wave signal and a cosθ side rectangular wave signal. The rectangular wave signals are input into a CPU 12, duty ratios and periods of the rectangular wave signals are measured by the CPU 12, and the abnormality is determined based thereon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resolver abnormality detection device that detects an abnormality based on an output signal from a resolver.

  In the following Patent Document 1, the difference between the integrated value of the first half period and the integrated value of the second half period of the sine wave signal waveform or cosine wave signal waveform obtained by detecting the output signal of the resolver is detected, and the vertical symmetry of the waveform is determined. It was detected that the collapse occurred, and the resolver abnormality was detected.

JP 2000-39336 A

  In this conventional resolver abnormality detection, a high-speed signal processing circuit is required to accurately grasp the sine wave signal waveform or cosine wave signal waveform obtained by detecting the output signal of the resolver, as well as integration. Since the arithmetic processing is complicated, there is a problem that the circuit becomes complicated and large in size.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a resolver abnormality detection device capable of detecting resolver abnormality with a simple circuit configuration.

  In order to achieve this object, in the present invention, a rectangular wave signal is obtained by comparing at least one of a sine wave signal or a cosine wave signal obtained by detecting an output signal of a resolver with a predetermined threshold value. The comparator includes an output comparator, and an abnormality determination unit that determines an abnormality of the resolver based on the duty ratio of the rectangular wave signal output from the comparator or the period of the rectangular wave signal.

  According to the present invention, a comparator that outputs a rectangular wave signal by comparing at least one of a sine wave signal or a cosine wave signal obtained by detecting an output signal of a resolver with a predetermined threshold, and a comparison The abnormality of the resolver can be easily detected by the abnormality determining means for determining the abnormality of the resolver based on the duty ratio of the rectangular wave signal output from the detector or the period of the rectangular wave signal.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, components having the same function are denoted by the same reference numerals, and repeated description thereof is omitted.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a first embodiment of the present invention. The configuration of the first embodiment will be described with reference to FIG.

  An excitation signal f (t) having a predetermined frequency is applied to the resolver 1 from the excitation signal output circuit 9, and two output signals f (t) that are amplitude-modulated according to the axial angle θ (electrical angle) of the resolver 1. sin θ and f (t) cos θ are output, and these two signals are synchronously detected by the synchronous detection circuits 2 and 3 with the excitation signal f (t) to obtain sin θ and cos θ.

  On the other hand, sin φ and cos φ obtained from the value φ of the up / down counter 10 indicating the resolver-digital conversion result are generated by the sin φ / cos φ generation circuit 6 and a product-sum operation (multipliers 4, 5) is performed between sin θ and cos θ. And the adder 7) calculates the deviation sin (θ−φ). The compensator 8 raises / lowers the up / down counter 10 so that this deviation becomes zero, so that φ = θ, and φ is output as a resolver-digital conversion result. Further, it is determined that the conversion result φ has crossed zero, and the pulse signal output circuit 11 outputs the Z signal. One pulse of the Z signal is output per one electrical angle rotation. In many cases, the actual resolver 1 is configured such that the angle θ is rotated uniformly multiple times for one mechanical rotation, and the number of rotations of θ for one mechanical rotation is determined by the resolver. It is expressed as the number of poles.

  Further, sin θ and cos θ are respectively input to the comparators 14 (first comparator) and 15 (second comparator), and the magnitudes of sin θ and cos θ are determined with respect to a predetermined threshold 16 (Vref1). Each is configured to be converted into a sin θ side rectangular wave signal and a cos θ side rectangular wave signal. These rectangular wave signals are input to the CPU 12 (abnormality determination means), and the CPU 12 measures the duty ratio and period of these rectangular wave signals to determine the abnormality.

  Next, the operation of the first embodiment will be described with reference to FIGS. In FIG. 1, the predetermined threshold 16 (Vref1) is set equal to the average value (ave) of sin θ and cos θ when the resolver 1 is normal. Therefore, when the resolver 1 is normal, the predetermined thresholds 16 and 15 The duty ratio of the sin θ side rectangular wave signal and the cos θ side rectangular wave signal which are the outputs of sin θ and cos θ compared to 16 (Vref1) is substantially equal to 50% as shown in FIG. 2A (sin θ in FIG. 2). This is the same for the cos θ side. However, if an abnormality occurs in the transformation ratio of the resolver 1 (rotor eccentricity, partial deformation, chipping, etc.), sin θ and cos θ are distorted (FIG. 2B), and the respective outputs of the comparator 10 are rectangular. The duty ratio of the wave signal changes. In the first embodiment, the change in the duty ratio is to be regarded as an abnormal state. For example, the absolute value of the deviation amount from 50% of the duty ratio Duty (sin) of the sin θ side rectangular wave signal in the CPU 12 is calculated. When the predetermined value TH (50%) is exceeded, it can be determined that there is an abnormality. However, in the first embodiment, this predetermined value TH (50%) is exceeded in order to prevent erroneous diagnosis due to noise or the like. When the state continues for a predetermined number of counts (50%), it is determined as abnormal.

  When the resolver 1 is normal and the rotational speed is constant, the duty ratio of the sin θ side rectangular wave signal and the cos θ side rectangular wave signal is substantially equal to 50%. However, when the rotational speed changes, these rectangular waves Since the duty ratio of the signal fluctuates, the predetermined value TH (50%) is determined in consideration of these fluctuations and circuit variation factors such as DC offset. However, if the predetermined value TH (50%) is set so that an abnormality is not erroneously detected even in the change rate of the rotational speed in all cases, the allowable amount of deviation becomes large, and detection of the abnormality that is originally detected is detected. Since the sensitivity is reduced, in the first embodiment, when the rate of change of the rotation speed is large (for example, when the rotating machine is a drive motor of an electric vehicle, when the brake is depressed or the accelerator is opened) When the degree exceeds a predetermined value), the diagnosis is interrupted.

  Further, in the first embodiment, in order to avoid misdiagnosis, it is determined that an abnormality occurs when the deviation of the duty ratio continues a predetermined number of times. For example, a part of the rotor of the resolver 1 is For a periodic waveform abnormality that occurs when it is deformed, the deviation of the duty ratio does not occur continuously (FIG. 2B), so the abnormality cannot be detected. In order to cope with this problem, in the first embodiment, even when the duty ratio deviation is not continuous, the duty ratio deviation is periodically detected, and the period constitutes the number of poles of the resolver 1. When the state coincident with the pole position to be exceeded exceeds a predetermined number of counts (C50%), an abnormality process is performed. As a result, the detection sensitivity of abnormality diagnosis in which abnormal states occur periodically, such as partial deformation or chipping of the rotor of the resonance lever 1, is improved.

  Next, details of the operation of the first embodiment will be described with reference to the flowchart of FIG. Although only the sin θ side will be described with reference to FIG. 3, the cos θ side can be handled in the same manner, and thus the description of the cos θ side is omitted.

  First, abnormality diagnosis of the resolver 1 is started, variables i, i (*), j, and k used for calculation are initialized in S101, and abnormality diagnosis logic is started. Here, the variable i indicates the number of consecutive abnormality determinations, the variables j and k indicate the pole position of the resolver 1, the * of the variable i (*) is a symbol indicating a wild card, and the * indicates the pole of the resolver 1 from 1. Enter the position. For example, when the number of resolver poles is 4, the variable i (*) indicates i (1), i (2), i (3), i (4). In the process of S101, these variables i (1), It shows that i (2), i (3), and i (4) are all initialized to 0. Next, measurement of the duty ratio of the sin θ side rectangular wave signal (FIG. 2B) is performed by the CPU 12, and the duty ratio measured upon completion of the measurement of the duty ratio (S102) is represented by a variable Duty (sin) (j). (J takes the value of 1 to the number of resolver poles) (S103). Next, it is determined whether or not the vehicle is currently accelerating or decelerating. Here, it is determined that the vehicle is accelerating if the accelerator opening is greater than or equal to a predetermined value, and is decelerating if the brake pedal force is greater than or equal to the predetermined value. If it is determined that the vehicle is accelerating or decelerating, the diagnostic logic is interrupted to initialize the variables i, i (*), j, and k, and the process returns to the duty ratio measurement completion interrupt waiting state. If it is determined that the vehicle is not accelerating or decelerating (that is, traveling at a constant speed), the process proceeds to S105. In S105, the difference between the measured duty ratio Duty (sin) (j) and the duty ratio 50% obtained when the resolver 1 is normal is the predetermined value TH (50%), which is the abnormal determination threshold value of the duty ratio. Determine if it has exceeded. If the predetermined value TH (50%) is not exceeded, a variable i indicating the number of consecutive abnormality determinations is initialized (S107), and the process proceeds to the next S108. If the predetermined value TH (50%) is exceeded, the variable i indicating the number of consecutive abnormality determinations is incremented by 1 (S106), and the process proceeds to the next S108.

  In S108, it is determined whether or not the variable i exceeds a predetermined number count (50%) that is a threshold value of the number of abnormality determinations in the case of continuous abnormality. When it exceeds here, it determines with having detected the continuous abnormality by this abnormality diagnosis logic. If not, the process proceeds to the next S109. Next, it is determined whether or not the variable j indicating the pole position of the measured duty ratio is greater than or equal to the number of poles of the resolver 1. If the number is not greater than the number of poles, the variable j is incremented by 1 (S110), and the process returns to the duty ratio measurement completion interrupt wait state. If the number is greater than or equal to the number of poles, the variable j is initialized to 1 in the next S111. The above is the continuous abnormality occurrence detection logic when abnormality occurs continuously. From here onwards, there is a periodic abnormality detection logic for detecting abnormalities that occur periodically, such as partial deformation and chipping of the rotor of the resonance lever 1.

  In the cycle abnormality detection logic, first, the variable j is initialized to 1 in S111, and the duty ratio Duty (sin) (k) (k is 1) measured in the continuous abnormality determination stored in S103. Takes the value of the number of resolver poles, and is the same value as j (however, a mechanical period j advances in time) and the duty ratio 50% obtained when the resolver 1 is normal is a predetermined value TH It is determined again whether or not (50%) is exceeded (S112). If the predetermined value TH (50%) is not exceeded, a variable i (k) indicating the number of consecutive times for each pole position in the cycle abnormality determination is initialized to 0 (S114), and the process proceeds to the next S115. . The reason why the variable i (k) is initialized to 0 is that an abnormality is determined when periodic abnormalities occur continuously, and an abnormal condition is not determined when abnormalities do not occur continuously due to noise or the like.

  If it exceeds the predetermined value TH (50%), the variable i (k) is increased by 1 (S113), and the process proceeds to the next S115. Next, it is determined whether or not the variable i (k) exceeds a predetermined number count (C50%) that is a threshold value of the number of abnormality determinations in the case of a cycle abnormality. When it exceeds here, it determines with having detected the period abnormality by this period abnormality detection logic. If not, the process proceeds to the next S116. In S116, it is determined whether or not the variable k indicating the pole position at which the periodic abnormality is determined is equal to or greater than the number of poles of the resolver 1. If the number is not greater than the number of poles, the variable k is incremented by 1 (S117), and the process returns to the beginning of the cycle abnormality detection logic. If the number is greater than or equal to the number of poles, the variable k is initialized and the process returns to the duty ratio measurement completion interrupt wait state.

  For example, as shown in FIG. 2B, when the number of poles of the resolver is 4 and the pole position 2 is abnormal, only Duty (sin) (2) exceeds the predetermined value TH (50%) in the determination in S105. Since the duty ratios of the other pole positions 1, 3, and 4 do not exceed the predetermined value TH (50%), the variable i is initialized to 0 by S107 at these pole positions. Not. However, since Duty (sin) (2) exceeds a predetermined value TH (50%) in S112 every mechanical cycle, the variable i (2) for each pole position increases (S113), and the variable i (2) Exceeds a predetermined value (count (C50%)) and is determined to be abnormal. On the other hand, Duty (sin) (1), Duty (sin) (3), and Duty (sin) (4) at other pole positions do not exceed the predetermined value TH (50%) as determined in S112. Since the variables i (1), i (3), and i (4) are initialized to 0, the predetermined value count (C50%) is not exceeded (S115).

  According to the first embodiment, the comparators 14 and 15 convert sin θ and cos θ into sin θ-side rectangular wave signals and cos θ-side rectangular wave signals, and compare the duty ratios of these rectangular wave signals with the normal duty ratios. With this simple circuit configuration, it is possible to detect the abnormality of the transformation ratio of the resolver 1 and the periodically occurring abnormality, and to improve the reliability of the resolver-digital conversion result.

  Next, a second embodiment will be described. The configuration diagram illustrating the second embodiment and the waveform example of each part when an assumed abnormality occurs are the same as those in FIGS. 1 and 2 used in the description of the first embodiment. In the second embodiment, attention is paid to the fact that the continuity of the measured duty ratio is lost when there is an abnormality in the transformation ratio of the resolver 1 (rotor eccentricity, partial deformation, chipping, etc.). For example, the difference between the duty ratio Duty (sin) (T1) of the sin θ side rectangular wave signal corresponding to an arbitrary period and the duty ratio Duty (sin) (T2) of the sin θ side rectangular wave signal corresponding to the next one period Can be determined as abnormal when the value exceeds a predetermined value TH (cont), but in the second embodiment, in order to prevent erroneous diagnosis due to noise or the like, a state exceeding the predetermined value TH (cont) When a predetermined number of counts (cont) occurs within a predetermined time time (cont), it is determined that there is an abnormality. In the second embodiment, diagnosis is also performed on the periodic continuity of each rectangular wave signal output from the comparator 10 together. For example, the period length Prod (sin) of sin θ at an arbitrary timing. When the difference between (T1) and the period length Prod (sin) (T2) of sin θ measured next time exceeds a predetermined value TH (prod), it can be determined that there is an abnormality. In the second embodiment, In order to prevent erroneous diagnosis due to noise or the like, an abnormality is determined when a state exceeding the predetermined value TH (prod) occurs count (prod) a predetermined number of times within a predetermined time time (prod).

  Note that the diagnosis interruption conditions and the respective predetermined values TH (cont) and TH (prod) are similar to those of the first embodiment in the circuit-like manner such as the variation due to the rate of change of the rotational speed and the DC offset. The determination is made in consideration of the variation, and the diagnosis is interrupted when the rate of change in the rotational speed is large. Further, the predetermined times time (count) and time (prod) are set within an abnormal continuation time allowed by the system using the resonance lever 1.

  Furthermore, the predetermined threshold value 16 (Vref1) of the comparators 14 and 15 can be detected in principle as long as it is within the voltage range taken by sin θ and cos θ, but here the diagnosis in the first embodiment is also performed. For the reason that it can be performed at the same time, it is set equal to the average value (ave) of sin θ and cos θ in the normal state as in the first embodiment.

  The detailed operation of the second embodiment will be described with reference to the flowchart of FIG. Note that this flowchart will be described only for sin θ as in the flowchart of FIG. 3, but since the cos θ side can be handled in the same manner, description on the cos θ side is omitted.

  Two types of periodic interrupts are prepared for abnormality diagnosis in the second embodiment. One is an interrupt that occurs every predetermined time time (cont) for determining the continuity of the duty ratio measurement value of the rectangular wave signal output from the comparator 14, and the continuity of the duty ratio is impaired in this interrupt processing. A variable m indicating the number of times is initialized (FIG. 4B). The other is an interrupt that occurs every predetermined time time (prod) for determining the periodic continuity of the rectangular wave signal output from the comparator 10, and is a variable n that indicates the number of times that the periodic continuity is impaired in this interrupt process. Is initialized (FIG. 4C).

  After the abnormality diagnosis is started, first, in S201, variables m and n used for calculation are initialized, and the above-described two types of interrupts are permitted. Next, with the end of the measurement of the duty ratio of the sin θ side rectangular wave signal (S203), the measured duty ratio is transferred to the variable Duty (sin) (T2) (S205). Further, the above-described duty ratio measurement time T2 is transferred, and the value of the free-run timer (free (t)) representing the current time is transferred to the variable Prod (T2), and the time Prod ( T2) -Prod (T1) is transferred to variable Prod (sin) (T2) (S205). In next S206, it is determined whether or not the vehicle is currently accelerating or decelerating (the determination method is the same as that in FIG. 3 and the description is omitted). If it is determined that the vehicle is accelerating or decelerating, the diagnosis logic is interrupted, the variables m and n are initialized (S207), and the measured values at the measurement time T2 are measured at the measurement time T1. Transfer to the value variable (S204), and return to the state of waiting for the duty ratio measurement completion interrupt.

  If it is determined that the vehicle is not accelerating or decelerating, the process proceeds to S208. In S208, the absolute value of the difference between the duty ratio Duty (sin) (T2) at the measurement time T2 and the duty ratio Duty (sin) (Tl) measured at the previous measurement time T1 determines the continuity of the duty ratio. It is determined whether or not a predetermined value TH (cont) has been exceeded. If it is determined that the duty ratio is not exceeded, a variable m indicating the number of consecutive times that the continuity of the duty ratio is impaired is initialized (S209), and each measurement value at the measurement time T2 is measured at the measurement time Tl. Transfer to the value variable (S204), and return to the state of waiting for the duty ratio measurement completion interrupt. If it is determined that the duty ratio has been exceeded, it is determined that the measured duty ratio is not continuous, and a variable m indicating the number of consecutive times that the duty ratio continuity is impaired is increased by 1 (S210), and the next S211 is performed. Go ahead.

  Next, it is determined whether or not the variable m has exceeded a predetermined number of counts (cont) for determining the continuity of the duty ratio (S211). If it is determined in S211 that it has been exceeded, it is determined that a duty ratio continuity abnormality is detected by the abnormality diagnosis logic. If not, the process proceeds to the next S212. In S212, the difference between the cycle length Prod (sin) (T2) at the measurement time T2 and the cycle length Prod (sin) (T1) at the measurement time T1 measured last time is a predetermined value TH (prod) for determining the continuity of the cycle. ) Is exceeded. If it is determined that the value does not exceed, the variable n indicating the number of consecutive times in which the continuity of the cycle is impaired is initialized (S213), and each measured value at the measurement time T2 is measured at the measurement time Tl. (S204) and return to the duty ratio measurement completion interrupt wait state. If it is determined here that the measured period has been exceeded, it is determined that there is no continuity in the measured period, 1 is added to the variable n indicating the number of continuations in which the continuity of the period is impaired (S214), and the process proceeds to the next S215 . In S215, it is determined whether or not the variable n has exceeded a predetermined value count (prod) of the number of consecutive times for determining the continuity of the cycle. If it is determined that the value has exceeded, it is determined that a periodic continuity abnormality is detected by the abnormality diagnosis logic. If not exceeded, each measurement value at the measurement time T2 is transferred to the variable of the measurement value at the measurement time Tl (S204), and the process returns to the duty ratio measurement completion interrupt wait state.

  In the second embodiment, it is also possible to detect a periodic abnormality as in the first embodiment.

  According to the second embodiment, the transformer ratio abnormality of the resolver 1 is detected with a simple circuit configuration for diagnosing continuity and periodic continuity of the duty ratio of the sin θ side rectangular wave signal and the cos θ side rectangular wave signal. In addition, it is possible to detect periodically occurring abnormalities, and to improve the reliability of the resolver-digital conversion result.

  Next, a third embodiment will be described with reference to FIGS. FIG. 5 is a time chart showing an example of the waveform of each part when an abnormality assumed in the third embodiment occurs, and FIG. 6 is a flowchart for explaining the abnormality diagnosis procedure in the third embodiment. The configuration diagram of the embodiment is the same as that of FIG. 1 showing the configuration diagram of the first embodiment, and a description thereof will be omitted. However, since only the predetermined threshold value 16 (Vref2) is different, the predetermined threshold value 16 ( Vref2) will be described later.

  In the third embodiment, when a transformer ratio abnormality (rotor eccentricity, partial deformation, chipping, etc.) of the resolver 1 or a DC offset abnormality of sin θ or cos θ occurs, the duty of the sin θ side rectangular wave signal The focus is on the difference between the measured value of the ratio (first duty ratio) and the measured value of the duty ratio (second duty ratio) of the cos θ side rectangular wave signal. For example, the cos θ side rectangle corresponding to one arbitrary period The difference between the duty ratio Duty (cos) (T1) of the wave signal and the duty ratio Duty (cos) (T1) of the sin θ side rectangular wave signal measured on the sin θ side whose phase is delayed by 90 ° with respect to cos θ is predetermined. When the value TH (diff) is exceeded, it can be determined that there is an abnormality. In the third embodiment, in order to prevent erroneous diagnosis due to noise or the like, this predetermined value TH (dif) When a state exceeding f) occurs continuously count (diff) a predetermined number of times, it is determined that there is an abnormality. Unlike the first and second embodiments, the predetermined threshold 16 (Vref2) is set to a value different from the average value (ave) of sin θ and cos θ during normal operation. In the third embodiment, the predetermined threshold 16 (Vref2) is set to about 70% of the maximum amplitude of sin θ and cos θ in order to increase detection sensitivity. The diagnosis interruption condition and the predetermined predetermined value TH (diff) are determined in consideration of fluctuations due to the change rate of the rotation speed and circuit variations such as a DC offset, as in the first embodiment. When the rate of change of the rotational speed is large, the diagnosis is interrupted.

  The detailed operation of the third embodiment will be described with reference to the flowchart of FIG. After the abnormality diagnosis is started, first, a variable p indicating the continuous number of duty ratio relative deviations of the sin θ side rectangular wave signal and the cos θ side rectangular wave signal is initialized (S301). Next, when the measurement of the duty ratio of the cos θ side rectangular wave signal is completed (S302), the measured duty ratio is transferred to the variable Duty (cos) (T1) (S303). Next, it is determined whether or not the vehicle is currently accelerating or decelerating (S304) (the determination method is the same as in FIG. 3 and the description is omitted). If it is determined that the vehicle is accelerating or decelerating, the diagnostic logic is interrupted, the variable p is initialized (S301), and the process returns to the duty ratio measurement completion interrupt wait state. If it is determined that the vehicle is not accelerating or decelerating, the process proceeds to the next S305. When the measurement of the duty ratio of the sin θ-side rectangular wave signal is completed in S305 (S305), the measured duty ratio is transferred to the variable Duty (sin) (T1) (S306). Next, it is determined whether or not the vehicle is currently accelerating or decelerating (S307) (the determination method is the same as in FIG. 3 and the description is omitted). If it is determined that the vehicle is accelerating or decelerating, the diagnostic logic is interrupted, the variable p is initialized (S301), and the process returns to the duty ratio measurement completion interrupt wait state. If it is determined that the vehicle is not accelerating or decelerating, the process proceeds to S308. The absolute value of the difference between the duty ratios Duty (sin) (Tl) and Duty (cos) (Tl) measured in S308 is a predetermined value for detecting the relative deviation of the duty ratio between the sin θ side rectangular wave signal and the cos θ side rectangular wave signal. It is determined whether or not the value TH (diff) has been exceeded. If it is determined that the value does not exceed, the variable p is initialized (S301), and the process returns to the state of waiting for a duty ratio measurement completion interrupt. If it is determined that the value has been exceeded, 1 is added to the variable p (S309), and the process proceeds to the next S310. In S310, it is determined whether or not the variable p has exceeded a predetermined number count (diff) of consecutive times for determining the relative deviation of the duty ratio between the sin θ side rectangular wave signal and the cos θ side rectangular wave signal. If it is determined that it has not exceeded, the process returns to the duty ratio measurement completion interrupt wait state. If it is determined that it has exceeded, it is determined that an abnormality in the relative deviation of the duty ratio between the sin θ side rectangular wave signal and the cos θ side rectangular wave signal is detected by the abnormality diagnosis logic.

  In the third embodiment as well, it is possible to detect a periodic abnormality as in the first embodiment.

  According to the third embodiment, when the transformer ratio abnormality of the resolver 1 or the DC offset abnormality of sin θ or cos θ occurs, the measured duty ratio of the sin θ side rectangular wave signal and the duty ratio of the cos θ side rectangular wave signal It is possible to detect a transformer ratio abnormality of the resolver 1 and a DC offset abnormality of sin θ or cos θ with a simple circuit configuration that determines that an abnormality occurs due to a difference in measurement values, and to improve the reliability of the resolver-digital conversion result. it can.

  Subsequently, the fourth embodiment will be described with reference to FIGS. 7, 8 and 9. FIG. 7 is a block diagram showing the fourth embodiment, FIG. 8 is a time chart showing an example of the waveform of each part when an abnormality assumed in the fourth embodiment occurs, and FIG. 9 shows the fourth embodiment. It is a flowchart for demonstrating the abnormality diagnosis procedure in this form.

In the fourth embodiment, sin θ and cos θ obtained in a normal resolver digital conversion process are respectively input to the two systems of comparators 17, and the first threshold 22 (Vref (+)), second The threshold value 21 (Vref (−)) is determined to be a magnitude, and a sin θ (+) side rectangular wave signal, a sin θ (−) side rectangular wave signal, a cos θ (+) side rectangular wave signal, and a cos θ (−) side rectangular. It is configured to be converted into a wave signal. The sin θ (+) side rectangular wave signal, the sin θ (−) side rectangular wave signal, the cos θ (+) side rectangular wave signal, and the cos θ (−) side rectangular wave signal are input to the CPU 12, and the CPU 12 receives the respective rectangular wave signals. Measure the duty ratio. Here, the first threshold 22 (Vref (+)) is a value obtained by adding a predetermined value (ΔVref) to the average value (ave) of sin θ and cos θ in a normal state, and the second threshold 21 (Vref (−)). Is set equal to a value obtained by subtracting a predetermined value (ΔVref) from the average value (ave) of sin θ and cos θ in a normal state.
Vref (+) = ave + ΔVref
Vref (−) = ave−ΔVref
The first threshold value 22 (Vref (+)) and the second threshold value 21 (Vref (−)) are always the first threshold value 22 (Vref (+)) and the second threshold value 21 (Vref (−)) even when the amplitudes of sin θ and cos θ are minimum. 2 must be set so as to cross the threshold value 21 (Vref (−)), and by setting it as large as possible within the range of the condition, the detection sensitivity of the abnormality can be improved.

  In the fourth embodiment. The predetermined value ΔVref is set so as to be located at about 70% of the amplitude standard value of sin θ and cos θ. When configured as described above, the comparator 17 (third comparator) on the side of the first threshold value 22 (Vref (+)) of sin θ, for example, the sum of two measured duty ratio values that are continuously measured in the normal state. And the duty ratio (third duty ratio) Duty (sin) (+) of the sin θ (+) side rectangular wave signal output by the second threshold value 21 (Vref (−)) side comparator 18 (the fourth duty ratio). The sum of the duty ratio (fourth duty ratio) Duty (sin) (−) of the sin θ (−) side rectangular wave signal output by the comparator) is almost 100%. However, when a transformation ratio abnormality (rotor eccentricity, partial deformation, chipping, etc.) of the resolver 1 or a direct current offset abnormality of sin θ or cos θ occurs, the vertical symmetry of sin θ or cos θ is lost, so the duty ratio Duty (sin ) (+) And duty ratio Duty (sin) (−), the sum of the two duty ratios does not become 100%.

  In the fourth embodiment, this phenomenon is regarded as an abnormal state. From 100% of the sum of the two duty ratios of the duty ratio Duty (sin) (+) and the duty ratio Duty (sin) (−). When the absolute value of the deviation amount exceeds a predetermined value TH (100%), it can be determined that there is an abnormality. In the fourth embodiment, this predetermined value is used to prevent erroneous diagnosis due to noise or the like. When a state exceeding TH (100%) (total abnormality) occurs for a predetermined number of counts (100%) within a predetermined time time (100%), it is determined as abnormal.

  The diagnosis interruption condition and the predetermined value TH (100%) are determined in consideration of fluctuations due to the change rate of the rotation speed and circuit variations such as DC offset, as in the first embodiment. When the rate of change of the rotational speed is large, the diagnosis is interrupted.

  The detailed operation of the fourth embodiment will be described with reference to the flowchart of FIG. In the flowchart of FIG. 9, only the sin θ side will be described, but the cos θ side can be handled in the same manner as the sin θ side, and thus the description thereof will be omitted. In this abnormality diagnosis, there is an interrupt (FIG. 9B) that occurs every time interval time (100%) for performing abnormality determination. In this interrupt process, the first threshold 22 (Vref (+)), the first The variable q indicating the number of times of detecting the total abnormality of the duty ratio of the sin θ (+) side rectangular wave signal and the sin θ (−) side rectangular wave signal output from the comparator 17 by the threshold value 21 (Vref (−)) of 2 is initially set. Turn into.

  After the abnormality diagnosis is started, the variable q is first initialized (S401), and the above-mentioned time (100%) interrupt is permitted (S402). Next, with the end of the measurement of the duty ratio of the sin θ (+) side rectangular wave signal (S403), the measured duty ratio is transferred to the variable Duty (sin) (+) (S404). Next, it is determined whether or not the vehicle is currently accelerating or decelerating (the determination method is the same as in FIG. 3 and description thereof is omitted). If it is determined that the vehicle is accelerating or decelerating, the diagnostic logic is interrupted and the process returns to the state of waiting for a duty ratio measurement completion interrupt. If it is determined that the vehicle is not accelerating or decelerating, the process proceeds to the next S406. When the measurement of the duty ratio of the sin θ (−) side rectangular wave signal is completed in S406, the measured duty ratio is transferred to the variable Duty (sin) (−) (S407).

  Next, it is determined whether or not the vehicle is currently accelerating or decelerating (S408) (the determination method is the same as in FIG. 3 and the description is omitted). If it is determined that the vehicle is accelerating or decelerating, the diagnostic logic is interrupted and the process returns to the state of waiting for a duty ratio measurement completion interrupt. If it is determined that the vehicle is not accelerating or decelerating, the process proceeds to the next S409. The absolute value of a value obtained by subtracting 100% from the sum of the duty ratios Duty (sin) (+) and Duty (sin) (−) measured in S409 is a predetermined value TH (100 %) Is exceeded. If it is determined that it has not exceeded, the process returns to the duty ratio measurement completion interrupt wait state. If it is determined that the value has been exceeded, 1 is added to the variable q (S410), and the process proceeds to the next S411. In S411, it is determined whether or not the variable q has exceeded a predetermined number of counts (100%). If it is determined that it has not exceeded, the process returns to the duty ratio measurement completion interrupt wait state. If it is determined that the duty ratio has been exceeded, it is determined that the total abnormality state of the duty ratio is detected by the abnormality diagnosis logic.

  In the fourth embodiment, it is also possible to detect a periodic abnormality as in the first embodiment.

  According to the fourth embodiment, when a transformer ratio abnormality of the resolver 1 or a direct current offset abnormality of sin θ or cos θ occurs, for example, the duty ratio Duty (sin) ( +) And duty ratio Duty (sin) (-) is a simple circuit configuration that determines that the sum of the two duty ratios does not reach 100%, and resolves the transformer 1 transformer ratio abnormality and sinθ or cosθ DC offset abnormality. And the reliability of the resolver-digital conversion result can be improved.

  Next, a fifth embodiment will be described with reference to FIGS. 10, 11, and 12. FIG. 10 is a block diagram showing the fifth embodiment, FIG. 11 is a time chart showing examples of waveforms at various parts when an abnormality assumed in the fifth embodiment occurs, and FIG. 12 shows the fifth embodiment. It is a flowchart for demonstrating the diagnostic procedure in form of this.

  In the fifth embodiment, as shown in FIG. 10, two types of resolver output signals f (t) sinθ and f (t) cosθ before synchronous detection are converted into comparators 25 (fifth comparators), 26 ( (Sixth comparator), and each signal is judged to be large or small with respect to a predetermined threshold 27 (Vref3), f (t) sin θ resolver output rectangular wave signal, f (t) cos θ resolver output rectangle It is configured to be converted into a wave signal. Synchronous detection 2 is generated after sin φ and cos φ are generated by sin φ / cos φ generation 6, and product-sum operation (multipliers 4, 5 and adder 7) is performed between f (t) sinθ and f (t) cosθ. Is going.

  The f (t) sinθ resolver output rectangular wave signal and the f (t) cosθ resolver output rectangular wave signal output from the comparators 25 and 26 are the falling edge delay circuits 28 (first removal means), 29 (second Is removed, and the frequency component of the excitation signal f (t) is removed and converted into a sin θ side rectangular wave signal (third rectangular wave signal) and a cos θ side rectangular wave signal (fourth rectangular wave signal). The CPU 12 measures each duty ratio. A low-pass filter may be used in place of the falling edge delay circuits 28 and 29. Here, the predetermined threshold 27 (Vref3) must be set so as to cross the predetermined threshold 27 (Vref3) without fail even when the amplitude of the output signal of the resolver 1 is minimum. The delay time (Td) of the delay circuits 28 and 29 at the falling edge is set to one period or more of the excitation signal f (t).

  When configured as described above, while both the output signals f (t) sinθ and f (t) cosθ of the resolver 1 are normal (the transformation ratio of both output signals is the same), for example, the cos side rectangular wave signal The duty ratio Duty (cos) (half) and the duty ratio Duty (sin) (half) of the sin-side rectangular wave signal delayed by 90 ° from it take substantially the same value. However, if the up / down symmetry of the output signal waveform of the resolver 1 is broken due to an abnormal transformation ratio of the resolver 1 (a relative deviation of the transformation ratio corresponding to the two outputs) or a DC offset abnormality of the output signal of the resolver 1, cos The two duty ratios of the duty ratio Duty (cos) (half) of the side rectangular wave signal and the duty ratio Duty (sin) (half) of the sin rectangular wave signal do not match. In the fifth embodiment, this phenomenon is regarded as an abnormal state. The duty ratio Duty (cos) (half) of the cos side rectangular wave signal and the duty ratio Duty (sin) (sin) of the sin side rectangular wave signal If the difference between the two duty ratios of half) exceeds a predetermined value TH (half), it can be determined that there is an abnormality. In the fifth embodiment, in order to prevent erroneous diagnosis due to noise or the like, When a state exceeding the predetermined value TH (half) is continued for a predetermined number of counts (half), it is determined that there is an abnormality.

  In FIG. 11, the signal modulated by the excitation signal f (t) is expressed by painting the modulated signal with a vertical line. This is because the frequency of the excitation signal f (t), which is the modulation signal, is very high compared to the frequencies of sin θ and cos θ, which are the modulated signals, and the modulation phase and waveform of the modulation signal are the same as in the fifth embodiment. Since the direct relationship is thin, the emphasis is on facilitating understanding, and notation is omitted. In addition, the diagnosis interruption condition and the predetermined value TH (ha1f) are determined in consideration of fluctuations due to the change rate of the rotation speed and circuit variations such as a direct current offset, as in the first embodiment. When the rate of change in the rotational speed is large, the diagnosis is interrupted.

  The detailed operation of the fifth embodiment will be described with reference to the flowchart of FIG. After the abnormality diagnosis is started, first, a variable r indicating the continuous number of duty ratio relative deviations of the sin θ side rectangular wave signal and the cos θ side rectangular wave signal is initialized (S501). Next, with the end of the measurement of the duty ratio of the cos θ side rectangular wave signal (S502), the measured duty ratio is transferred to the variable Duty (cos) (ha1f) (S503). Next, it is determined whether or not the vehicle is currently accelerating or decelerating (the determination method is the same as in FIG. 3 and the description thereof is omitted). If it is determined that the vehicle is accelerating or decelerating, the diagnostic logic is interrupted, the variable r is initialized (S501), and the process returns to the duty ratio measurement completion interrupt waiting state. If it is determined that the vehicle is not accelerating or decelerating, the process proceeds to the next S505. When the measurement of the duty ratio of the sin θ-side rectangular wave signal ends in S505, the measured duty ratio is transferred to the variable Duty (sin) (ha1f) (S506). Next, it is determined whether or not the vehicle is currently accelerating or decelerating (S507) (the determination method is the same as in FIG. 3 and the description is omitted). If it is determined that the vehicle is accelerating or decelerating, the diagnostic logic is interrupted, the variable r is initialized (S501), and the process returns to the duty ratio measurement completion interrupt waiting state. If it is determined that the vehicle is not accelerating or decelerating, the process proceeds to the next S508. The absolute value of the difference between the duty ratios Duty (sin) (ha1f) and Duty (cos) (ha1f) measured in S508 is a predetermined value for detecting the duty ratio relative deviation between the sin θ side rectangular wave signal and the cos θ side rectangular wave signal. It is determined whether or not the value TH (ha1f) has been exceeded. If it is determined that the value does not exceed, the variable r is initialized (S501), and the process returns to the duty ratio measurement completion interrupt wait state. If it is determined that the variable has been exceeded, the variable r is increased by 1 (S509), and the process proceeds to the next S510. In S510, it is determined whether or not the variable r has exceeded a predetermined value count (half) of the continuous number of times for determining the relative deviation of the duty ratio between the sin θ side rectangular wave signal and the cos θ side rectangular wave signal. If it is determined that it has not exceeded, the process returns to the duty ratio measurement completion interrupt wait state. If it is determined that it has exceeded, it is determined that an abnormality in the relative deviation of the duty ratio between the sin θ side rectangular wave signal and the cos θ side rectangular wave signal is detected by the abnormality diagnosis logic.

  According to the fifth embodiment, the transformer ratio abnormality of the resolver 1 and the DC offset abnormality of sin θ and cos θ can be detected with a relatively simple and small circuit, and the reliability of the resolver-to-digital conversion result can be improved. It becomes.

  In the above-described embodiments, all of them can be implemented with the same or most of them with a common hardware configuration, and a plurality of diagnoses may be performed simultaneously. Further, the plurality of means for determining the size with different threshold values may be configured to share the comparator by controlling the threshold value from the CPU 12 or the like and changing it with time.

The block diagram which shows 1st and 2nd embodiment. The time chart which shows the example of the waveform of each part when abnormality which assumes in 1st and 2nd embodiment has generate | occur | produced. The flowchart for demonstrating the abnormality diagnosis procedure in 1st Embodiment. The flowchart for demonstrating the abnormality diagnosis procedure in 2nd Embodiment. The time chart which shows the example of the waveform of each part when abnormality which assumes in 3rd Embodiment occurs. The flowchart for demonstrating the abnormality diagnosis procedure in 3rd Embodiment. The block diagram which shows 4th Embodiment. The time chart which shows the example of the waveform of each part when abnormality which assumes in 4th Embodiment occurs. The flowchart for demonstrating the abnormality diagnosis procedure in 4th Embodiment. The block diagram which shows 5th Embodiment. The time chart which shows the example of the waveform of each part when abnormality which assumed in 5th Embodiment generate | occur | produces The flowchart for demonstrating the abnormality diagnosis procedure in 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Resolver 2, 3 ... Synchronous detection circuit 12 ... CPU
DESCRIPTION OF SYMBOLS 14 ... 1st comparator 15 ... 2nd comparator 16, 27 ... Predetermined threshold value 17, 19 ... 3rd comparator 18, 20 ... 4th comparator 21 ... 2nd threshold value 22 ... 1st Threshold 25 ... Fifth comparator 26 ... Sixth comparator 28, 29 ... Falling delay circuit

Claims (14)

In the resolver abnormality detection device for detecting an abnormality of the resolver based on a sine wave signal obtained by detecting an output signal from the resolver or a cosine wave signal,
A comparator that compares at least one of the sine wave signal or the cosine wave signal with a predetermined threshold and outputs a rectangular wave signal;
An abnormality detection device for a resolver, comprising: abnormality determination means for determining abnormality of the resolver based on a duty ratio of the rectangular wave signal output from the comparator or a period of the rectangular wave signal.   The predetermined threshold is an average value of the sine wave signal or the cosine wave signal output when the resolver is normal, and the abnormality determination unit is configured to output the duty of the rectangular wave signal output from the comparator. The resolver abnormality detection device according to claim 1, wherein the abnormality is determined when the ratio deviates from 50% by a predetermined value or more.   The abnormality determining means determines that an abnormality occurs when a state where the duty ratio of the rectangular wave signal output from the comparator deviates from 50% by a predetermined value or more continues for a predetermined number of times. The resolver abnormality detection device according to claim 2.   The predetermined threshold is a predetermined value equal to or less than a maximum value and a minimum value of the sine wave signal or the cosine wave signal that is output when the resolver is normal. The duty ratio of each period of the output rectangular wave signal is detected, and the difference between the detected duty ratio of the rectangular wave signal and the duty ratio of the rectangular wave signal one period before is greater than or equal to a predetermined value. The resolver abnormality detection device according to claim 1, wherein the abnormality is determined to be abnormal.   The predetermined threshold is a predetermined value that is equal to or less than the maximum value of the sine wave signal or the cosine wave signal that is output when the resolver is normal and is equal to or greater than the minimum value, and the abnormality determination unit outputs from the comparator The period length, which is the length per period of the rectangular wave signal, is detected every period, and the difference between the detected period length of the rectangular wave signal and the period length of the rectangular wave signal one period before is predetermined. The resolver abnormality detection apparatus according to claim 1, wherein an abnormality is determined when the value is equal to or greater than a value.   The abnormality determining means detects a state where a difference between the detected duty ratio of the rectangular wave signal and the duty ratio of the rectangular wave signal one period before is equal to or greater than the predetermined value within a predetermined time. 5. The resolver abnormality detection device according to claim 4, wherein the abnormality is determined to be abnormal in the case of failure.   The abnormality determination means detects a state where a difference between the period length of the detected rectangular wave signal and the period length of the rectangular wave signal one period before is equal to or more than the predetermined value within a predetermined time. 6. The resolver abnormality detection device according to claim 5, wherein the abnormality is determined to be abnormal in the case of failure.   A first comparator that outputs the rectangular wave signal by comparing the sine wave signal with a predetermined threshold value, and a second comparison that outputs the rectangular wave signal by comparing the cosine wave signal with the predetermined threshold value The abnormality determining means includes a first duty ratio that is a duty ratio of the rectangular wave signal output from the first comparator and a rectangular wave signal output from the second comparator. 2. A second duty ratio, which is a duty ratio, is compared, and an abnormality is determined when a difference between the first duty ratio and the second duty ratio is equal to or greater than a predetermined value. The resolver abnormality detection device described.   The abnormality determining means is the first duty ratio which is the duty ratio of the rectangular wave signal output from the first comparator and the duty ratio of the rectangular wave signal output from the second comparator. Comparing with a second duty ratio, and determining that an abnormality occurs when a state where the difference between the first duty ratio and the second duty ratio is more than the predetermined value continues for a predetermined number of times. The resolver abnormality detection device according to claim 8, wherein:   At least one of the sine wave signal or the cosine wave signal obtained by detecting the output signal of the resolver, and a predetermined value to an average value of the sine wave signal or the cosine wave signal output when the resolver is normal A third comparator that compares a first threshold value that is a value obtained by adding together, at least one of the sine wave signal or the cosine wave signal, and a sine wave signal or cosine output when the resolver is normal A fourth comparator that compares a second threshold value that is a value obtained by subtracting the predetermined value from an average value of the wave signal, and the abnormality determination means is a rectangle output from the third comparator. The sum of the third duty ratio, which is the duty ratio of the wave signal, and the fourth duty ratio, which is the duty ratio of the rectangular wave signal output from the fourth comparator, deviates from 100% by a predetermined value or more. Place Abnormality detection device of the resolver according to claim 1, wherein determining that abnormality.   The abnormality determining means is the third duty ratio, which is the duty ratio of the rectangular wave signal output from the third comparator, and the duty ratio of the rectangular wave signal output from the fourth comparator. The resolver abnormality detection device according to claim 10, wherein an abnormality is determined when a state in which a value obtained by adding the fourth duty ratio deviates from 100% by the predetermined value or more continues for a predetermined number of times or more. .   The abnormality determination means determines that an abnormality occurs when an abnormality in the duty ratio or period length of the rectangular wave signal is continuously generated at a predetermined pole of the resolver. The resolver abnormality detection device according to any one of the above. In the resolver abnormality detection device for detecting an abnormality of the resolver based on an output signal from the resolver,
A fifth comparator for outputting a rectangular wave signal by comparing a modulated sine wave signal of the output signal of the resolver with a predetermined threshold, a modulated cosine wave signal of the output signal of the resolver, and the predetermined threshold And a sixth comparator that outputs a rectangular wave signal.
A first removing means for removing the modulation signal from the first rectangular wave signal output from the fifth comparator; and a modulation signal from the second rectangular wave signal output from the sixth comparator. Second removal means to
The duty ratio of the third rectangular wave signal from which the modulation signal has been removed by the first removal means is compared with the duty ratio of the fourth rectangular wave signal from which the modulation signal has been removed by the second removal means. And an abnormality determining means for determining an abnormality when a difference between the duty ratio of the third rectangular wave signal and the duty ratio of the fourth rectangular wave signal is equal to or greater than a predetermined value. Anomaly detection device.   The abnormality determination means determines that an abnormality is detected when a state where the difference between the duty ratio of the third rectangular wave signal and the duty ratio of the fourth rectangular wave signal is more than the predetermined value continues for a predetermined number of times. The resolver abnormality detection device according to claim 13, wherein the determination is performed.

Images