JP3216491B2 - Resolver abnormality detection apparatus and method - 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 detecting apparatus and method for detecting an abnormality occurring in a resolver, a wiring around the resolver, or a signal processing circuit related to the resolver.

[0002]

2. Description of the Related Art For example, when controlling the rotation speed of a traveling motor of an electric vehicle, it is necessary to accurately rotate a vector of a current supplied to the traveling motor in accordance with the rotation of the traveling motor. Therefore, in an electric vehicle, it is necessary to accurately detect the rotor position (angle) of a traveling motor of the electric vehicle. In the field of accurately detecting the position of the rotating body such as this type of field, the position (angle) of the rotating body
A resolver is used as a means for detecting.

[0003]

However, even if a device using a resolver is used as the angle detecting device, a signal processing circuit for determining the angle of the rotating body from the output of the resolver or the occurrence of disconnection or the like in the wiring related to the resolver. If an error occurs, accurate angle detection will not be foolproof. In the device described in JP-A-3-78668,
Although it is possible to detect a wiring abnormality such as a disconnection, it cannot detect an abnormality in a signal processing circuit.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is possible to detect abnormalities other than wiring abnormalities or to detect various types of abnormalities by making a signal processing system redundant. It is an object of the present invention to provide an apparatus and a method which enable the control of a traction motor of an electric vehicle and the like.

[0005]

In order to achieve the above object, a first configuration of the present invention is to modulate the amplitude of a reference signal by sinθ when a reference signal having a predetermined periodic waveform is supplied. A resolver for generating a sin signal having a waveform and a cos signal having a waveform amplitude-modulated by cos θ (where θ is the angle of a rotating body provided with the resolver), and an angle θ is detected based on the sin signal and the cos signal. in the resolver abnormality detection device for use with the angle detection device including an angle detection signal processing means, and resorcinol in synchronization with the peak of the reference signal
Sin and cos signals are input from Luba and sin θ
And cos θ, sin θ and cos θ, and angle θ
Are assigned to these sinθ and cosθ
More specifically , the angle is independent of the angle detection signal processing means.
and abnormality detection signal processing means for determining a theta, between the angular theta detected by the detected angle theta and abnormality detection signal processing means by the angle detection signal processing means is an abnormality in the angle detection signal processing means A signal processing abnormality detecting means for detecting that a difference that can be considered to have occurred, and an abnormality detecting signal.
Sin θ and cos θ detected by the signal processing means are s
When the condition of in ² θ + cos ² θ = 1 is not satisfied
The resolver and signal processing means for angle detection or abnormal detection
Abnormality in the wiring between the output signal processing means or inside the resolver
And a resolver abnormality detecting means for determining that the error has occurred .

As described above, in this configuration, two types of signal processing means (signal processing means for angle detection and signal processing for abnormality detection) are provided. Both detect the angle θ independently and based on the sin signal and the cos signal. Therefore,
If there is a significant difference between the angle θ detected by the angle detection signal processing means and the angle θ detected by the abnormality detection signal processing means, at least the sin signal and c
It can be considered that an abnormality has occurred at a stage after the generation of the os signal. As described above, in the present configuration, since the difference between the detection results by the two signal processing units is used,
An abnormality of the angle detection signal processing means or the abnormality detection signal processing means is detected. Further, when the wiring between the resolver and the two signal processing means is another wiring, the wiring between the resolver and the signal processing means for angle detection (disconnection, short circuit, etc.) and the trouble between the resolver and the signal processing means for abnormality detection are detected. An abnormality (interruption, short circuit, etc.) in the wiring between them is also detected.

[0007]

In this configuration, the abnormality detection signal processing means detects sin θ and cos θ. The resolver abnormality detecting means uses the fact that sin ² θ + cos ² θ = 1 should be satisfied if the sin signal and the cos signal are normal, and uses the fact that the sin signal and the cos signal are abnormal, that is, an angle detection signal processing means. And an abnormality occurring at a stage prior to the abnormality detection signal processing means. Therefore,
In this configuration, in addition to the abnormality detected by the signal processing abnormality detection means, at least an abnormality occurring inside the resolver is detected. Further, when the wiring between the resolver and the two signal processing means is a common wiring, the wiring between the resolver and the signal processing means for angle detection (disconnection, short-circuit, etc.) or the trouble between the resolver and the signal processing means for abnormality detection. An abnormality (interruption, short circuit, etc.) in the wiring between them is also detected. Further, the type of abnormality can be distinguished depending on whether the abnormality is detected by the signal processing abnormality detecting means or the resolver abnormality detecting means.

According to a second configuration of the present invention, in the first configuration, when the amplitude of the reference signal does not exceed a predetermined value for a predetermined time or more, it is determined that the peak of the reference signal does not arrive at a normal cycle. And a reference abnormality detecting means. In the above-described first configuration, since the abnormality detection signal processing unit inputs the sin signal and the cos signal in synchronization with the peak of the reference signal, when the peak of the reference signal does not arrive at a normal cycle, sin θ and cos θ cannot be detected. In this configuration, reference abnormality detecting means is further added to the second configuration, and the abnormality of the reference signal is detected by the determination relating to the amplitude of the reference signal. Thus, in this configuration, in addition to the abnormality that can be detected in the first configuration, an abnormality in the reference signal is detected. Further, the abnormality of the reference signal is detected separately from other abnormalities.

[0010] A third configuration of the present invention comprises a first step of supplying a reference signal having a predetermined periodic waveform to a resolver attached to a rotating body;
a sin signal having a waveform amplitude-modulated by nθ and co
cos signal having a waveform amplitude-modulated by sθ (where θ
Is a second step of inputting the angle of the rotating body provided with the resolver from the resolver, a sin signal and a cos
A third step of detecting the angle θ of the rotating body based on a signal, the resolver abnormality detection process that is executed with an angle detecting method having the same peak of the reference signal
Input the sin signal and cos signal from the resolver
To obtain sin θ and cos θ, sin θ and cos θ
And a table that associates the angle θ with these sin θ and
Cosθ, independent of the third step, the angle
There is a difference between the fourth step for obtaining θ and the angle θ detected in the third step and the angle θ detected in the fourth step that can be considered that the third step is not executed normally. And a fourth step of detecting that
Sin θ and cos θ detected in the step are sin ² θ
+ Cos ^{2 When} the condition of θ = 1 is not satisfied,
An abnormality has occurred in the wiring around the luba or inside the resolver.
And a sixth step of determining .
In this configuration, a method that can be implemented in the first configuration is realized.

[0011]

According to a fourth configuration of the present invention, in the third configuration, when the amplitude of the reference signal does not exceed a predetermined value for a predetermined time or more, it is determined that the peak of the reference signal does not arrive at a normal cycle. And a seventh step of performing the following. In this configuration, a method that can be implemented in the second configuration is realized.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system configuration of an electric vehicle according to an embodiment of the present invention. In the system of this figure, a three-phase AC PM motor, that is, a three-phase AC synchronous motor excited by a permanent magnet, is used as the motor 10 for running the vehicle. A battery 12 is provided as a drive power source for the motor 10.
The discharge output 2 is supplied to the motor 10 after being converted into a three-phase AC by the inverter 14. The power conversion operation by the inverter 14 and the opening and closing operation of the relay unit 16 provided between the battery 12 and the inverter 14
It is controlled by an electronic control unit (ECU) 18. E
The CU 18 opens and closes the relay unit 16 according to the operation of the ignition switch. The ECU 18 also receives an accelerator signal indicating the amount of depression of the accelerator pedal by the vehicle operator, a brake signal indicating the amount of depression of the brake pedal, a shift position signal indicating the shift position, and the like, while passing through the rotation sensor signal processing circuit 20. A sin signal and a cos signal are input from a resolver 22 attached to the motor 10, and a current command for the motor 10 is generated using these signals. The ECU 18 switches a switching signal for switching the switching elements Q <b> 1 to Q <b> 6 constituting the inverter 14 based on the generated current command and a detected value of the current of the motor 10 fed back from the inverter 14, for example, a PWM (pulse width modulation) signal. Is generated and supplied to the inverter 14. ECU
The other 18 monitors the input voltage to the inverter 14. The inverter 14 also includes a capacitor C for smoothing an input from the battery 12 and a discharge resistor R of the capacitor C.

The resolver 22 and the rotation sensor signal processing circuit 20 have a more detailed hardware configuration as shown in FIG. First, the resolver 22 is a motor 1
0 stator or fixed part 24 fixed to the vehicle
And a rotating part 26 fixed to the rotor shaft.
The fixed portion 24 is provided with an exciting winding 28, a sin winding 30 and a cos winding 32. The excitation winding 28 is connected between terminals REF and REFG of an oscillation circuit 36 inside the rotation sensor signal processing circuit 20 via a wiring 34,
A reference signal having a predetermined periodic waveform is supplied from the oscillation circuit. The waveform of the reference signal is
For example, as shown by a broken line in FIG.
Sin ωt (where A: amplitude, ω: angular frequency, t: time). The sin winding 30 and the cos winding 32 are connected between terminals SIN and SING or between COS and COSG of a signal processing circuit (R / D converter) 42 in the rotation sensor signal processing circuit 20 via wirings 38 and 40, respectively. And the sine signal or the cos signal is R / D
It is supplied to the converter 42. The sin signal and the cos signal have waveforms obtained by amplitude-modulating the reference signal in accordance with the rotation portion 26 and, consequently, the rotor angle θ. That is, when the reference signal is, for example, a sine wave = A · sin ωt, the sin winding 30 and the cos winding 32
As shown in (1), a sin signal represented by K · A · sin ωt · sin θ and a cos signal represented by K · A · sin ωt · cos θ are obtained (K is an amplitude coefficient). The R / D converter 42 detects the position of the rotating part 26 of the resolver 22, that is, the rotor angle θ based on the sin signal and the cos signal.

The rotation sensor signal processing circuit 20 includes two oscillators A and R / D converter 42,
/ D converters 44 and 46, comparator 48 for comparing a reference signal with a reference amplitude, and control CPU 5
It has 0. The comparator 48 detects a peak of the reference signal by comparing the reference signal with a predetermined reference amplitude, that is, an expected peak value of the reference signal. A / D converters 44 and 46
Respectively converts the sine signal or the cos signal into A / at the timing of the peak detected by the comparator 48.
D-converted and obtained signals, ie, SIN signal and CO
The S signal is supplied to the control CPU 50. The SIN signal COS signal obtained by the A / D converters 44 and 46 is
Therefore, as shown in FIG. 4, the signal represents sin θ or cos θ, respectively.

The control CPU 50 executes an operation as shown in FIG.

The control CPU 50 first sets the comparator 4
8 detects the peak of the reference signal (1
00), the SIN signal from the A / D converter 44 (10
2) Also, the COS signal from the A / D converter 46 is (1)
04), respectively. The control CPU 50
A table in which θ and cos θ are associated with θ is built in, and the angle θ is estimated by referring to this table with the input SIN signal and COS signal values (1
06). On the other hand, the control CPU 50 also inputs the angle θ obtained from the R / D converter 42 (108). The control CPU 50 determines the angle θ input in step 108
Then, the absolute value of the difference between the angles θ estimated in step 106 is obtained, and it is determined whether or not the obtained angle difference exceeds a predetermined abnormality detection threshold value (112). If not, it is determined that an accurate angle θ is obtained from the signal processing circuit 42 (114), and the control CPU 50
The operation returns to step 100. Conversely, if it is determined that the value exceeds the abnormality detection threshold, the signal processing circuit 4
It is determined that an accurate angle θ is not obtained from 2 (11)
6) In response to this, predetermined measures against abnormalities such as a measure to stop driving the motor 10 and a measure to execute control using the angle θ estimated in step 106 are executed (1).
18).

That is, the angle θ estimated on the basis of the SIN signal and the COS signal is, for example, about one digit lower in accuracy than the angle θ obtained from the signal processing circuit 42 when each unit of the apparatus is operating normally. It cannot be used for controlling the inverter 14 at all times. However, it is sufficient to verify whether the angle θ obtained from the R / D converter 42 is normal. In the present embodiment, attention is paid to this point, and it is determined whether or not an accurate angle θ is obtained from the R / D converter 42. As a result, it is possible to detect an abnormality of the R / D converter 42 that could not be detected conventionally. At that time, relatively inexpensive members such as the A / D converters 44 and 46 and the comparator 48 are sufficient, and generally an expensive R
It is not necessary to add one more / D converter.

The control CPU 50 determines these two types of angles θ.
In addition to the abnormality detection using the equation ( ² ), the wiring abnormality detection using the relationship sin ² θ + cos ² θ = 1 is also performed. That is, after executing steps 102 and 104, the control CPU 50 calculates the sum of the square of the SIN signal and the square of the COS signal (120), and determines whether or not the calculated sum is substantially equal to 1. (122). That is, the SIN signal is s
signal represents cos θ, and the sum obtained in step 120 is sin ² θ + co.
s ² θ. Therefore, by determining whether or not the obtained sum is equal to 1, it is possible to know whether or not an abnormality has occurred in the wirings 38 and 40 or the inside of the resolver 22. If it is determined in step 122 that there is an abnormality, 116
Is performed, and if it is determined that there is no abnormality, the operation from step 108 is performed. As described above, according to the present embodiment, the abnormality of the wirings 38 and 40 can be detected separately from the abnormality of the R / D converter 42, and differs depending on the location of the abnormality when executing step 118. It will also be possible to take action.

The control CPU 50 also detects an abnormality in the reference signal. That is, step 102
If the peak of the reference signal cannot be detected (100) until the peak detection timer reset (124) and restarted (126) before the execution of the steps 104 and 104 expires (128), the control CPU 50 sets the reference It is considered that the signal peak does not arrive at a normal cycle, that is, that the oscillation circuit 36 and the like have an abnormality,
The operation after step 116 is executed. Thus, according to the present embodiment, it is possible to cope with the abnormality of the reference signal and to detect this reference signal separately from other abnormalities. Can also.

As described above, according to the present embodiment, it is possible to detect an abnormality in the resolver 22 and its surrounding wiring or circuit while specifying the abnormal location.
On the U18 side, different abnormal measures can be taken according to the detected contents, and thus an abnormality detecting device suitable for an electric vehicle can be obtained.

In FIG. 2, the comparator 48
Operate the A / D converters 44 and 46 at the peak timing of the reference signal detected by the A / D converter.
If a converter can be used, it is not necessary to synchronize the A / D conversion operations in A / D converters 44 and 46 with the peak timing. That is, A / D
SIN obtained at high speed from converters 44 and 46
The control CPU 50 latches the signal and the COS signal at the peak timing detected by the comparator 48.
Such a configuration may be adopted. Strictly speaking, whether the R / D converter 42 or the A / D converter 44 or the like has an abnormality cannot be distinguished by the threshold value determination in the step 112. Is an R / D having a more complicated circuit configuration.
Since the probability of converter 42 failure is higher, an abnormality of R / D converter 42 can be detected by the operation of step 112. When it is necessary to distinguish between an abnormality in the R / D converter 42 and an abnormality in the A / D converter 44 and the like, the angle θ is estimated based on each phase current of the motor 10 fed back from the inverter 14 to the ECU 18. , May be used as auxiliary information. In the above-described embodiment, a single resolver 22 is used.
Although the angle θ is estimated or detected by two means sharing the above, the angle θ may be estimated or detected by three or more means.

[0024]

As described above, according to the first and third configurations of the present invention, the angles θ detected by the two signal processing means or the two methods are compared with each other, and the result is compared. Since the abnormality is determined based on the abnormality, it is possible to detect an abnormality occurring at least at a later stage than the generation of the sine signal and the cos signal, including an abnormality in the signal processing. At this time, since at least one of the two types of θ detection is realized by referring to the table, it is not necessary to use two expensive members, for example, two R / D converters.

According to the first and third configurations of the present invention, sin θ and cos θ are further detected and sin ² θ + co
Since the determination is performed under the condition of s ² θ = 1, at least an abnormality occurring inside the resolver can be detected. Further, the type of abnormality can be distinguished depending on whether it is detected by comparing angles θ or by detection under the condition of sin ² θ + cos ² θ = 1. Further, by using both of the abnormality detections, it is possible to detect a wiring abnormality regardless of whether the wiring between the resolver and the two signal processing means is common or separate.

According to the second and fourth configurations of the present invention, in addition, when the amplitude of the reference signal does not exceed the predetermined value for a predetermined time or more, the peak of the reference signal does not arrive at a normal cycle. Because it was determined that
While distinguishing reference signal abnormalities from other abnormalities,
Can be detected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a hardware configuration of a resolver and a rotation sensor signal processing circuit in the embodiment.

FIG. 3 is a time chart showing waveforms of input / output signals of a resolver.

FIG. 4 is a time chart showing a waveform of an input / output signal of a resolver and a waveform of an output signal of an A / D converter.

FIG. 5 is a flowchart showing a flow of an operation of a control CPU.

[Explanation of symbols]

10 motor, 18 ECU (electronic control unit), 2
0 rotation sensor signal processing circuit, 22 resolver, 36
Oscillation circuit, 38, 40 wiring, 42 signal processing circuit (R
/ D converter), 44, 46 A / D converter, 4
8 Comparator, 50 control CPU, θ angle.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01D 5/00-5/62 G01B ⁷ /00-7/30

Claims (4)

(57) [Claims] When a reference signal having a predetermined periodic waveform is supplied, a resolver for generating a sin signal having a waveform obtained by amplitude-modulating the reference signal with sin θ and a cos signal having a waveform obtained by amplitude-modulating the reference signal with cos θ (wherein θ is the angle of the rotating body with the resolver)
When, in the resolver abnormality detection device for use with the angle detection device including an angle detection signal processing means for detecting the angle θ based on the sin signal and the cos signal, and from the resolver in synchronization with the peak of the reference signal si
n signal and cos signal are input and sin θ and cos θ
And associating sin θ and cos θ with the angle θ
The table is referred to by these sinθ and cosθ.
The angle θ is obtained independently of the angle detection signal processing means. The abnormality detection signal processing means, the angle θ detected by the angle detection signal processing means and the angle θ detected by the abnormality detection signal processing means are detected. Between the angle θ
That difference may be considered abnormality occurs with the angle detection signal processing means occurs, a signal processing abnormality detecting means for detecting, sin [theta and cosθ detected by abnormality detection signal processing means sin ² θ + cos ² θ = If you do not meet the first condition, abnormality in internal wiring or a resolver between the resolver and the angle detection signal processing means or the abnormality detection signal processing means is generated, and the determining the resolver abnormality detection means, the A resolver abnormality detection device, comprising: 2. The resolver abnormality detection device according to claim 1, wherein when the amplitude of the reference signal does not exceed a predetermined value for a predetermined time or more, the reference which determines that the peak of the reference signal does not arrive in a normal cycle. A resolver abnormality detection device comprising abnormality detection means. 3. A first step of supplying a reference signal having a predetermined periodic waveform to a resolver attached to a rotating body, and a sin signal having a waveform obtained by amplitude-modulating the reference signal with sin θ and amplitude modulation with cos θ. A second step of inputting a cos signal (where θ is the angle of the rotating body provided with the resolver) having the above-mentioned waveform from the resolver, and a third step of detecting the angle θ of the rotating body based on the sin signal and the cos signal. a step, in the resolver abnormality detection process that is executed with an angle detection method having, si from the resolver in synchronization with the peak of the reference signal
n signal and cos signal are input and sin θ and cos θ
And associating sin θ and cos θ with the angle θ
The table is referred to by these sinθ and cosθ.
Te, and the third step and the fourth step of determining the angle θ independently between the angle θ detected by the detected angle θ and the fourth step in the third step, the third step is executed successfully that difference may be considered non occurs, a fifth step of detecting, the detected sinθ and cosθ in the fourth step s
If you do not meet the ^{in 2 θ + cos 2 θ =} 1 condition, the resolver abnormality detection method characterized by having abnormal internal wiring or a resolver near resolver has occurred, a sixth step determines that the. 4. The resolver abnormality detection method according to claim 3 , wherein if the amplitude of the reference signal does not exceed a predetermined value for a predetermined time or more, it is determined that the peak of the reference signal does not arrive at a normal cycle. A resolver abnormality detection method comprising seven steps.