JP2798340B2 - Resolver abnormality detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resolver abnormality detection circuit for detecting an abnormality in an angle detection signal of a resolver for detecting an angle of a rotating body or the like.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional example, and is a block diagram showing a schematic configuration of a conventional resolver feedback signal abnormality detection circuit in a speed control device in which control operation and abnormality detection are executed by one microcomputer. FIG. 7 is a flowchart showing an operation performed by the microcomputer shown in FIG. 6 for determining an abnormality of the resolver feedback signal.

In FIG. 6, reference numeral 1 denotes a resolver excitation power source,
Is a resolver for detecting the rotation angle of the control target, 3a is a sine wave signal fed back from the resolver 2 for control calculation, 3
b is a COS wave signal fed back from the resolver 2 for control calculation, 11 is an abnormality detection signal of the resolver, 1
2 is a resolver excitation power supply 1 and a SIN wave signal, COS
Resolver / digital converter for converting the feedback signals 3a and 3b of the wave signals into digital signals, and 13 is an angle signal θ converted by the resolver / digital converter 12.
(T) and 14 are speed command signals θ ′ (t) which are used as references when performing an abnormality determination of the resolver feedback signal, and 15 are inputting an angle signal θ (t) 13 and a speed command θ ′ (t) 14, respectively. It is a microcomputer that executes arithmetic processing for detecting an abnormality of a resolver feedback signal.

Next, the operation will be described. In FIG. 6, a feedback signal 3 output from the resolver 2 is shown.
a, 3b and the resolver excitation power supply 1 are input to a resolver / digital converter 12, and an angle signal θ (t) 13 is obtained. The speed command θ ′ (t) 14 and the angle signal θ (t) 13 for the controlled object whose angle is to be detected by the resolver 2
Is input to the microcomputer 15, and the program stored in the microcomputer 15 is used to execute FIG.
The microcomputer 15 outputs the abnormality detection signal 11 from the microcomputer 15 when it is determined that an abnormality has occurred.

Since the amplitude of the feedback signals 3a and 3b output from the resolver 2 is constantly changing while the controlled object is rotating, the feedback signals 3a and 3b are taken into the microcomputer 15 and Although it is difficult to determine the presence or absence of an abnormality, when an abnormality occurs in the resolver 2, the presence or absence of the abnormality is determined by using the fact that the output from the resolver / digital conversion circuit 12 stops at a certain value. It is possible. Sunup,
Speed command θ 'when controlling the speed of the controlled object
(T) By estimating the angle change amount from 14, an abnormality is determined by a method of detecting an abnormality of the resolver 2 from the difference from the actually measured angle change amount.

The operation of the abnormality determination processing executed in the microcomputer 15 will be described with reference to the flowchart shown in FIG. First, microcomputer 1
5 takes in the speed command θ '(t ₀ ) 14 (S71),
Next, the angle signal θ (t ₀ ) 13 is fetched (S72).
Next, the angle signal after a predetermined time _{t 1 θ (t 0 + t} 1) 13
Is again captured (S73), and the captured angle signal θ (t
₀ ) and θ (t ₀ + t ₁ ), the difference θ (t ₀ +
t ₁₎ for calculating the angle variation from -θ (t ₀₎ (S7
4). Thereafter, the amount of angle change θ ′ (t ₀ ) * t ₁ during normal operation is estimated from the speed command θ ′ (t ₀ ) 14 (S75).

Next, the calculated angle change θ (t ₀ +
t ₁ ) −θ (t ₀ ) is compared with the angle change θ ′ (t ₀ ) * t ₁ estimated in (e) (S 76), and the calculated result is compared with a reference value, and the difference is calculated. If larger,
It is determined that the control target is not rotating normally, and it is determined that one of the causes is an abnormality of the angle detection signal, for example, an abnormality such as disconnection of the resolver feedback signal, and outputs an abnormality detection signal 11. Here, in order to determine the cause of the abnormality when the angle detection signal of the resolver is abnormal, more condition judgments are required. Step S7 above
The series of processing from 1 to S77 is repeatedly executed in the microcomputer 15 to determine whether there is an abnormality (S77).

The time interval t ₁ for performing the abnormality detection must be selected according to the maximum rotation speed of the control object. If the rotation speed is high, a short time interval must be selected. This is because the control object to the abnormality detection time interval t ₁ is because in some cases run away by the abnormal angle detection.

FIG. 8 shows another conventional example.
No. 78668 discloses a "resolver disconnection detection device". The resolver signal 24b represented by Asinθ sinωt... (1) is converted into a phase represented by Asin θ cosωt. The signal 26 changed by 90 degrees and the other resolver signal 24c represented by Acos θ cos ωt (3) are added, full-wave rectified, and Asin (ωt + θ) (4) (Asin θ cos ωt + Asin θ sin ωt) Detecting an abnormality of the resolver by obtaining a signal 31 indicated by, and comparing the peak value of the signal 31 with the peak value of the signal 30 obtained by amplifying the full-wave rectification of the resolver excitation signal by the comparison circuit 32. It is.

In the above equations, θ: resolver detection circuit A: constant determined by the resolver excitation power supply and the transformation ratio of the resolver (A> 0) ω: each frequency of the resolver excitation power supply t: time.

FIG. 9 shows another conventional example.
No. 262415 discloses a "resolver angle detecting device". The resolver signal represented by the above formulas (1) and (2) is transmitted through demodulators 41 and 42 to Asin.
The signals 53 and 54 represented by θ and Acos θ are obtained, and are further squared by the multipliers 43 and 44 to obtain A ² sin ² θ and A ² c
Signals 55 and 56 indicated by os ² θ are obtained, and the signal level of a signal 57 indicated by A ² obtained by adding the signals 55 and 56 is monitored to detect an abnormality of the resolver signal.

As another technical reference related to the present invention, there is a "resolver excitation circuit" disclosed in Japanese Patent Application Laid-Open No. 62-298718.

[0013]

According to the abnormality detection circuit shown in FIG. 6 as described above, it is necessary to estimate the amount of change in the angle according to the rotational speed and to repeatedly determine whether there is an abnormality. There is a problem that the number of steps and the execution time occupied by the abnormality detection program among the programs in the microcomputer increase, and the execution speed of another program executed by the microcomputer decreases.

Further, according to the conventional example shown in FIG. 8, the position is set at 9 with respect to the frequency fluctuation of the excitation power supply and the ambient temperature fluctuation.
In order to change it to 0 degree constant, the phase circuit is complicated and
There has been a problem that the apparatus becomes expensive and increases the cost of the apparatus. Similarly, in the conventional example shown in FIG.
Since two multipliers are required, there has been a problem that the circuit configuration is complicated and expensive, which leads to an increase in the cost of the device.

The present invention has been made in order to solve such a problem, and it is possible to avoid an increase in the cost of the device by a simple circuit configuration and to reduce the rotation speed of other programs without reducing the execution speed of other programs. It is an object of the present invention to provide an abnormality detection circuit capable of detecting an abnormality of an angle detection signal such as a disconnection of a resolver feedback signal.

[0016]

A resolver abnormality detecting circuit according to the present invention comprises: a resolver for detecting an angle; a sine wave signal and a COS signal from the resolver;
Rectifying means for separately rectifying the resolver feedback signal of the wave signal, adding means for adding the two signals rectified by the rectifying means, and comparing the signal added by the adding means with a reference voltage to obtain the resolver. Feedback
And comparing means for judging an abnormality of the lock signal .

A synchronizing means for detecting an angle; a converting means for converting a synchro output from the synchronizing means into a resolver output;
Rectifying means for separately rectifying the resolver feedback signals of the IN wave signal and the COS wave signal; adding means for adding both signals rectified by the rectifying means; and a signal added by the adding means to a reference voltage. Before comparison
Comparing means for determining whether the resolver feedback signal is abnormal .

Further, a synchronizing means for detecting an angle, a rectifying means for separately rectifying a synchro output which is a three-phase alternating current from the synchronizing means, and both signals rectified by the rectifying means are added. Adding means for comparing the signal added by the adding means with a reference voltage ,
And a comparing means for judging abnormality of the synchro output .

[0019]

The resolver abnormality detection circuit according to the present invention rectifies the SIN wave signal and the COS wave signal of the resolver feedback signal, and uses the signal obtained by adding the DC SIN wave signal and the COS wave signal to the resolver feedback signal. Detects whether the signal is abnormal.

The resolver abnormality detection circuit according to the present invention uses the angle detector as a synchro, converts a synchro feedback signal into a SIN wave signal and a COS wave signal as a resolver feedback signal by a Scott transformer, and outputs the SIN wave signal and the COS wave signal. The presence or absence of an abnormality in the synchro feedback signal is detected by using a signal obtained by rectifying the COS wave signal and adding the two SIN wave signals and the COS wave signal that have become DC.

Further, in the resolver abnormality detection circuit according to the present invention, the angle detector is used as a synchro, and the three-phase alternating-current signals, which are synchro feedback signals, are separately rectified, and the respective three-phase alternating-current signals that have become DC are added. The presence or absence of an abnormality in the synchro feedback signal is detected using the signal.

[0022]

【Example】

[Embodiment 1] Hereinafter, an embodiment of a resolver abnormality detection circuit according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a resolver abnormality detection circuit according to the present invention. In the figure, 1 is a resolver excitation power supply, 2 is a resolver, and 3a is an SI fed back from the resolver 2.
An N-wave signal, 3b is a COS wave signal fed back from the resolver 2, 4a is a rectifier circuit for rectifying a SIN wave signal 3a fed back from the resolver 2, and 4b is a rectifier for rectifying a COS wave signal 3b fed back from the resolver 2. The circuit 5a is a signal obtained by rectifying the resolver feedback signal 3a of the SIN wave signal, and the reference numeral 5b is a signal obtained by rectifying the resolver feedback signal 3b of the COS wave signal.

6a is S which has become a DC after rectification.
A smoothing filter circuit for removing a ripple due to the excitation frequency of the resolver excitation power supply 1 in the resolver feedback signal 5a of the IN wave signal, and 6b is a resolver feedback signal 5 of the COS wave signal which has been rectified and turned into DC.
b, a smoothing filter circuit for removing a ripple component due to the excitation frequency of the resolver excitation power supply 1; 7; a rectified DC; and an addition circuit for adding a smoothed SIN wave signal and a smoothed resolver feedback signal of the COS wave signal; Reference numeral 8 denotes a signal obtained by adding a resolver feedback signal of the rectified SIN wave signal and COS wave signal by the addition circuit 7, reference numeral 9 denotes a reference voltage, and reference numeral 10 denotes a comparison between the signal 8 added by the addition circuit 7 and the reference voltage 9. A comparison circuit 11 is an abnormality detection signal output from the comparison circuit.

FIG. 2A is an explanatory diagram in which the vertical axis represents the amplitude value of the SIN wave signal 3a and the horizontal axis represents the resolver angle of the resolver feedback signal, and FIG. 5 is an explanatory diagram in which the vertical axis represents the amplitude value of the COS wave signal 3b and the horizontal axis represents the resolver angle.

FIG. 3A shows the value of the sine wave signal 3a in the resolver feedback signal after rectification on the vertical axis.
FIG. 3B is an explanatory view in which a horizontal axis indicates a resolver angle, and FIG.
FIG. 3 is an explanatory diagram in which the vertical axis represents the value of the COS wave signal 3b and the horizontal axis represents the resolver angle of the resolver feedback signal after rectification, and FIG. 3C further illustrates the rectified SIN wave signal and COS FIG. 5 is an explanatory diagram in which a vertical axis represents a signal 8 of a value obtained by adding wave signals and a horizontal axis represents a resolver angle.

SIN of the resolver feedback signal
The value 5a obtained by rectifying the wave signal 3a is represented by | Asin θ | (5), and the value 5b obtained by rectifying the COS wave signal 3b in the resolver feedback signal is represented by | Acos θ | (6) And a signal 8 having a value obtained by adding the rectified SIN wave signal and the COS wave signal is represented by the following Expression 1. In Expression 1, the expression following = (equal) corresponds to the resolver angle. The expression representing the signal 8 after the addition and the value following = (equal) are the signal 8 after the addition.
Is in the range of A to $ 2A.

[0027]

(Equation 1)

Next, the operation will be described. In FIG. 1, a sine wave signal 3a and a cosine wave signal 3b are fed back from the resolver 2 with a value corresponding to the resolver angle. The values are as shown in the above equations (1) and (2). 2 (a) and 2 (b) show the amplitude value of this waveform on the vertical axis and the resolver angle on the horizontal axis.
Is shown in

The sine wave signal 3a and the COS wave signal 3b fed back with a value corresponding to the resolver angle are rectified in rectifier circuits 4a and 4b, respectively, and converted into DC signals 5a and 5b. The DC signals 5a and 5b
Are as shown in equations (5) and (6). The values of the DC signals 5a and 5b on the vertical axis and the resolver angle on the horizontal axis are shown in FIGS. 3 (a) and 3 (b).

The DC signals 5a and 5b are smoothed by smoothing filters 6a and 6b for removing a ripple due to the excitation frequency of the resolver excitation power supply 1. The smoothed signals are added by an adding circuit 7 and output as an added signal 8. The value of the addition signal 8 is as shown in Expression 1. FIG. 3C shows the value of the addition signal 8 on the vertical axis and the resolver angle on the horizontal axis.

If the resolver feedback signals 3a and 3b are normal, the addition signal 8 is equal to or more than a predetermined value (A
Above). This signal is compared with a reference voltage 9 in a comparison circuit 10. The reference voltage 9 is set to a value slightly lower than A. Therefore, the comparison circuit 10 determines that the resolver feedback signal is normal when the addition signal 8 is larger than A, and determines that the resolver feedback signal is abnormal when the addition signal 8 is smaller than A, and outputs the abnormality detection signal 11.

[Second Embodiment] In the first embodiment, the detection means for detecting the angle of the control object is a resolver. In this embodiment, the control is performed using a synchro and a Scott transformer. Detect the target angle.

FIG. 4 is a block diagram showing a schematic configuration of this embodiment. The three-phase AC signal fed back from the synchro 21 is converted into a SIN signal by the Scott transformer 22.
It is converted into a wave signal and a resolver signal that is a COS wave signal, and detects an abnormality of the angle detector. Other configurations are the same as those of the first embodiment.

[Embodiment 3] The detecting means for detecting the angle of the controlled object in the first embodiment is a resolver. In this embodiment, a three-phase alternating current fed back from the synchro using a synchro is used. Rectify the signals separately,
By comparing the signal obtained by adding the DC three-phase AC signal with the reference voltage, when the voltage becomes equal to or lower than the reference voltage, it is detected as an abnormality of the angle detection signal such as disconnection of the synchro feedback signal.

FIG. 5 is a block diagram showing a schematic configuration of this embodiment. The three-phase AC signals fed back from the synchro 21 are converted into rectifier circuits 4a, 4b and 4 respectively.
c, converted into DC signals 5a, 5b and 5c, smoothed to DC with a small amount of ripple by smoothing filter circuits 6a, 6b and 6c, and the smoothed signals are added by an adding circuit 7 to obtain an addition signal 8. This signal is compared with the reference voltage 9 in the comparison circuit 10, and when the sum signal 8 is higher than the reference voltage 9, the synchro feedback signal is determined to be normal, and when the sum signal 8 is lower, the synchro feedback signal is determined to be abnormal. The signal 11 is output.
Other configurations are the same as those of the first embodiment.

[0036]

As described above, according to the resolver abnormality detection circuit according to the present invention, the SIN wave signal of the resolver feedback signal and the angle feedback signal of the COS wave signal are separately rectified, and the two SIN waves that have become DC are obtained. Signal, C
By comparing the signal obtained by adding the OS wave signal with the reference voltage, an abnormality is detected when the voltage becomes equal to or lower than the reference voltage. Therefore, the disconnection of the resolver feedback signal at any rotational speed with a simple circuit configuration is performed. An abnormality in the angle detection signal can be detected.

Further, according to the resolver abnormality detection circuit of the present invention, the angle detector is used as a synchro, and a synchro feedback signal is converted by a Scott transformer into a SIN wave signal and a COS wave signal which are resolver feedback signals. Even if the signal and the COS wave signal are rectified, disconnection of the resolver feedback signal, etc.
An abnormality in the angle detection signal can be detected.

Further, according to the resolver abnormality detection circuit according to the present invention, the angle detector is used as a synchro, and the three-phase AC signals which are synchro feedback signals are separately rectified.
Even if the signal obtained by adding each of the three-phase AC signals that have become DC is compared with a reference voltage, detecting an abnormality in the angle detection signal such as disconnection of the resolver feedback signal at any rotational speed with a simple circuit configuration. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a resolver abnormality detection circuit according to the present invention.

FIG. 2 is an explanatory diagram in which the vertical axis represents the amplitude value of the SIN wave signal and the horizontal axis represents the resolver angle of the resolver feedback signal, and COS represents the resolver feedback signal.
FIG. 5B is an explanatory diagram (b) in which the vertical axis represents the amplitude value of the wave signal and the horizontal axis represents the resolver angle.

FIG. 3 is an explanatory diagram (a) in which the value of a sine wave signal of the resolver feedback signal after rectification is plotted on the vertical axis and the angle of the resolver is plotted on the horizontal axis, and the value of the COS wave signal in the resolver feedback signal after rectification is plotted vertically. FIG. 7B is an explanatory diagram in which the axis and the resolver angle are plotted on the horizontal axis, and a vertical axis shows the value of the sum of the rectified SIN wave signal and the COS wave signal, and FIG. is there.

FIG. 4 is a block diagram showing a schematic configuration of a resolver abnormality detection circuit (second embodiment) according to the present invention.

FIG. 5 is a block diagram showing a schematic configuration of a resolver abnormality detection circuit (third embodiment) according to the present invention.

FIG. 6 is a block diagram showing a schematic configuration of a conventional resolver feedback signal abnormality detection circuit.

FIG. 7 is a flowchart showing an operation of the abnormality detection circuit shown in FIG. 6;

FIG. 8 is a block diagram showing a schematic configuration of a conventional resolver feedback signal abnormality detection circuit.

FIG. 9 is a block diagram showing a schematic configuration of a conventional resolver feedback signal abnormality detection circuit.

[Explanation of symbols]

 Reference Signs List 1 resolver excitation power supply 2 resolver 4a rectifier circuit 4b rectifier circuit 4c rectifier circuit 6a smoothing filter circuit 6b smoothing filter circuit 7 addition circuit 9 reference voltage 10 comparison circuit 11 abnormality detection signal 21 synchro 22 Scott transformer

Continuation of the front page (56) References JP-A-3-238317 (JP, A) JP-A-1-269012 (JP, A) JP-A-6-66593 (JP, A) JP-A-2-75517 (JP) , U) (58) Field surveyed (Int. Cl. ⁶ , DB name) G01D 5/245

Claims (3)

(57) [Claims] 1. A resolver means for detecting an angle,
Rectifying means for separately rectifying the resolver feedback signals of the SIN wave signal and the COS wave signal from the resolver means, adding means for adding both signals rectified by the rectifying means, Comparing the resolver feedback signal with a reference voltage.
A resolver abnormality detection circuit, comprising: comparison means for determining an abnormality of the signal. 2. Synchronizing means for detecting an angle,
Converting means for converting a synchro output from the synchronizing means into a resolver output;
Rectifying means for separately rectifying the resolver feedback signals of the wave signal and the COS wave signal, adding means for adding both signals rectified by the rectifying means, and comparing the signal added by the adding means with a reference voltage. And said
A resolver abnormality detection circuit, comprising: comparison means for determining abnormality of the resolver feedback signal . 3. A synchronizing means for detecting an angle,
Rectifying means for separately rectifying a synchro output which is a three-phase alternating current from the synchronizing means, adding means for adding both signals rectified by the rectifying means, and a reference voltage obtained by adding the signals added by the adding means. Compared to the sink
(B) a resolver abnormality detection circuit, comprising: comparison means for determining an abnormality in the output .