CN113484802A

CN113484802A - Fault detection method and device for rotary transformer

Info

Publication number: CN113484802A
Application number: CN202110802287.XA
Authority: CN
Inventors: 付凤超; 王辉; 霍炯
Original assignee: Hefei Yangguang Electric Power Technology Co ltd
Current assignee: Hefei Yangguang Electric Power Technology Co ltd
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2021-10-08
Anticipated expiration: 2041-07-15

Abstract

The embodiment of the invention discloses a fault detection method and device for a rotary transformer. The fault detection method of the rotary transformer comprises the following steps: collecting a first output signal and a second output signal of a rotary transformer; wherein the first output signal and the second output signal are in different phases; respectively determining the change conditions of the amplitude states of the first output signal and the second output signal within set time; and detecting whether the transmission line of the first output signal and the transmission line of the second output signal have disconnection faults or not according to the change condition of the amplitude states of the first output signal and the second output signal within the set time. According to the technical scheme of the embodiment of the invention, the condition that any one of the transmission line of the first output signal or the transmission line of the second output signal has the disconnection fault can be detected, and the accuracy of the disconnection fault detection of the rotary transformer is improved on the premise of ensuring the normal work of the electric automobile.

Description

Fault detection method and device for rotary transformer

Technical Field

The embodiment of the invention relates to the technical field of electric automobiles, in particular to a fault detection method and device for a rotary transformer.

Background

At present, an electric vehicle controller generally measures a rotation angle and a rotation speed of a motor by using a resolver, for example, the resolver can generate an induced electromotive force under the action of an input excitation signal, so as to output a signal representing a real-time rotation angle, so that the electric vehicle controller can determine the rotation angle and the rotation speed of the motor according to the signal.

In practical applications, the transmission line of the excitation signal and the transmission line of the signal representing the real-time rotation angle often have disconnection faults, so the disconnection faults need to be detected. However, the existing scheme is difficult to realize accurate detection of the disconnection fault under the condition of ensuring the normal work of the electric automobile.

Disclosure of Invention

The embodiment of the invention provides a fault detection method and device of a rotary transformer, which are used for improving the accuracy of the fault detection of the broken line of the rotary transformer on the premise of ensuring the normal work of an electric vehicle.

In a first aspect, an embodiment of the present invention provides a method for detecting a fault of a resolver, including:

collecting a first output signal and a second output signal of a rotary transformer; wherein the first output signal and the second output signal are out of phase;

respectively determining the change conditions of the amplitude states of the first output signal and the second output signal within set time;

and detecting whether the transmission line of the first output signal and the transmission line of the second output signal have line break faults or not according to the change conditions of the amplitude states of the first output signal and the second output signal in the set time.

Optionally, the first output signal is a sine signal, and the second output signal is a cosine signal.

Optionally, acquiring a first output signal and a second output signal of the resolver comprises:

sampling a first output signal and a second output signal of a resolver to determine an envelope signal of the first output signal and an envelope signal of the second output signal.

Optionally, sampling a first output signal and a second output signal of a resolver to determine an envelope signal of the first output signal and an envelope signal of the second output signal, comprising:

sampling the first output signal and the second output signal according to a set sampling frequency so as to acquire a set number of signal sampling points in each signal state judgment period of the first output signal and the second output signal;

and taking the maximum value of the absolute values of the amplitudes of the signal sampling points of the first output signal in each signal state judgment period as the amplitude of the envelope signal of the first output signal in the period, and taking the maximum value of the absolute values of the amplitudes of the signal sampling points of the second output signal in each signal state judgment period as the amplitude of the envelope signal of the second output signal in the period.

Optionally, the set sampling frequency is greater than a carrier frequency of the first output signal and the second output signal.

Optionally, the change condition of the amplitude state of the first output signal within a set time includes the number of changes of the amplitude state of the envelope signal of the first output signal within the set time; the change condition of the amplitude state of the second output signal in a set time comprises the change times of the amplitude state of the envelope signal of the second output signal in the set time.

Optionally, determining the change of the amplitude states of the first output signal and the second output signal within a set time respectively includes:

when the amplitude of the envelope signal of the first output signal is changed from being larger than a first set threshold to being smaller than a second set threshold, or is changed from being smaller than the second set threshold to being larger than the first set threshold, determining that the amplitude state of the envelope signal of the first output signal is changed; wherein the first set threshold is greater than the second set threshold;

when the amplitude of the envelope signal of the second output signal is changed from being larger than the first set threshold to being smaller than the second set threshold, or is changed from being smaller than the second set threshold to being larger than the first set threshold, determining that the amplitude state of the envelope signal of the second output signal is changed;

and respectively calculating the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in the set time.

Optionally, the first set threshold is smaller than a maximum value of amplitudes of the envelope signals of the first output signal and the second output signal, the second set threshold is larger than a minimum value of amplitudes of the envelope signals of the first output signal and the second output signal, and the first set threshold and the second set threshold differ by a set difference.

Optionally, detecting whether a disconnection fault occurs in the transmission line of the first output signal and the transmission line of the second output signal according to a change condition of the amplitude states of the first output signal and the second output signal within the set time includes:

and determining that one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault when an absolute value of a difference between the number of changes in the amplitude states of the envelope signals of the first output signal and the second output signal within the set time is greater than a set number.

Optionally, the resolver is used for detecting a rotation speed of a motor in an electric vehicle, and the set number of times is positively correlated with the rotation speed of the motor; or the set times are positively correlated with the fault maturation time of the transmission line of the first output signal and the transmission line of the second output signal; or the set times are positively correlated with the number of pole pairs of the rotary transformer.

Alternatively, when one of the numbers of changes in the amplitude state of the envelope signals of the first output signal and the second output signal within the set time is zero and the other is greater than the set number, it is determined that one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault, and the transmission line of the signal whose number of changes in the amplitude state of the envelope signal is zero is a line having a disconnection fault.

Optionally, the method for detecting whether a disconnection fault occurs in a transmission line of the first output signal and a transmission line of the second output signal according to changes of the amplitude states of the first output signal and the second output signal within the set time further includes:

and when the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in the set time are both larger than zero, determining that the transmission line of the first output signal and the transmission line of the second output signal both work normally.

and when one of the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in the set time is zero and the other is less than the set time, determining that the transmission line of the first output signal and the transmission line of the second output signal both work normally.

Optionally, the method further comprises:

and detecting whether the transmission line of the first output signal, the transmission line of the second output signal and the transmission line of the excitation signal input by the rotary transformer have disconnection faults or not according to the amplitudes of the first output signal and the second output signal in the set time.

Optionally, when the amplitudes of the first output signal and the second output signal are both zero within the set time, it is determined that the transmission line of the excitation signal has a disconnection fault, or the transmission line of the first output signal and the transmission line of the second output signal have a disconnection fault at the same time.

In a second aspect, an embodiment of the present invention further provides a fault detection apparatus for a resolver, including:

the signal acquisition module is used for acquiring a first output signal and a second output signal of the rotary transformer; wherein the first output signal and the second output signal are out of phase;

the change condition determining module is used for respectively determining the change conditions of the amplitude states of the first output signal and the second output signal within set time;

and the disconnection fault detection module is used for detecting whether the disconnection fault occurs on the transmission line of the first output signal and the transmission line of the second output signal according to the change condition of the amplitude states of the first output signal and the second output signal in the set time.

According to the fault detection method and device for the rotary transformer, provided by the embodiment of the invention, whether the transmission line of the first output signal and the transmission line of the second output signal have the disconnection fault or not is detected according to the change condition of the amplitude states of the first output signal and the second output signal of the rotary transformer in the set time, so that the disconnection fault detection of the rotary transformer is realized. The scheme can detect that one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault when the amplitude state of one of the first output signal and the second output signal changes within the set time, the change times are more than the set times, and the amplitude state of the other output signal does not change within the set time. And, through setting up the settlement time, help avoiding the problem that the fault maturation time is too short and arouse frequent parking among the prior art, even when resolver's output signal's frequency is higher, also can detect the broken string trouble according to the change condition of the amplitude state of first output signal and second output signal in the settlement time, help guaranteeing under the prerequisite of electric automobile normal work, promote resolver's broken string trouble detection's accuracy.

Drawings

Fig. 1 is a flowchart of a fault detection method for a resolver according to an embodiment of the present invention;

fig. 2 is a schematic block diagram of a control system of a resolver according to an embodiment of the present invention;

FIG. 3 is a waveform diagram of an output signal of a resolver according to an embodiment of the present invention;

fig. 4 is a waveform diagram of an envelope signal of an output signal of a resolver according to an embodiment of the present invention;

fig. 5 is a waveform diagram illustrating an envelope signal of an output signal of another resolver according to an embodiment of the present invention;

FIG. 6 is a flow chart of another method for detecting a fault in a resolver, according to an embodiment of the present invention;

fig. 7 is a schematic block diagram of a fault detection apparatus for a resolver according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a terminal according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

As mentioned in the background art, it is difficult for the existing solutions to achieve accurate detection of the disconnection fault under the condition of ensuring normal operation of the electric vehicle, and the inventors have found that the above problems occur due to: in an electric vehicle, a rotary transformer and a corresponding control component are generally connected by a wire harness and a connector, and when the electric vehicle passes through a bumpy road section, the vibration of the connector may cause a disconnection fault of a transmission line of an excitation signal and a transmission line of a signal representing a real-time rotation angle, so that the disconnection fault needs to be detected. In one scheme in the prior art, a decoding chip is used for acquiring an output signal of a rotary transformer, the decoding chip has a function of detecting a disconnection fault, but cannot set fault maturity time, is sensitive to the disconnection fault, and is easy to frequently trigger the fault if applied to an electric automobile controller, so that frequent parking is caused. Moreover, the decoding chip is expensive, which is not favorable for reducing the cost.

The signal representing the real-time rotation angle output by the resolver includes two output signals with different phases, for example, the two output signals may be orthogonal output signals with phases different by 90 °, and when a disconnection fault occurs in a transmission line of one of the signals and a transmission line of the other signal is normal, one output signal is zero and the other output signal is normal. Another scheme in the prior art determines whether a transmission line has a disconnection fault according to whether the amplitudes of the two output signals are zero or not, and whether the amplitudes of the two output signals are not zero or not. However, since the two output signals have different phases, when the resolver normally operates, one of the two output signals is zero, and the other output signal is not zero, so that the scheme is prone to misjudgment of a disconnection fault.

In addition, the connector in the electric vehicle often generates poor contact in a short time due to vibration, if the failure maturity time of the above prior art scheme is short, the connector immediately reports the failure when the poor contact occurs, so that the electric vehicle is frequently stopped, and if the failure maturity time is too long, the disconnection failure cannot be accurately reported when the frequency of the output signal of the rotary transformer is high.

In view of the above problems, an embodiment of the present invention provides a fault detection method for a resolver. Fig. 1 is a flowchart of a fault detection method for a resolver according to an embodiment of the present invention; fig. 2 is a schematic block diagram of a control system of a resolver according to an embodiment of the present invention. The present embodiment may be applicable to detecting a disconnection fault of a resolver, where the method may be performed by a fault detection apparatus of the resolver, where the apparatus may be implemented in a software and/or hardware manner, and the apparatus may be configured in a control system of the resolver, or may also be configured in an electronic device, such as a server or a terminal device, where a typical terminal device includes a mobile terminal, specifically includes a mobile phone, a computer, or a tablet computer. As shown in fig. 1, the method for detecting a fault of a resolver specifically includes:

and S110, collecting a first output signal and a second output signal of the rotary transformer.

The rotary transformer provided by the embodiment of the invention can be arranged in an electric automobile and is used for detecting the rotating angle and the rotating speed of a motor in the electric automobile. Illustratively, as shown in fig. 2, the control system of the resolver may include a Digital Signal Processing (DSP) device 10 and a conditioning circuit 20; the digital signal processing apparatus 10 includes a Pulse Width Modulation (PWM) signal generating unit 11 and an analog-to-digital converting unit 12; the conditioning circuit 20 comprises a drive conditioning circuit 21 and a feedback conditioning circuit 22; the PWM signal generating unit 11 may generate a PWM signal, and the excitation conditioning circuit 121 may convert the PWM signal into an excitation signal and transmit the excitation signal to the resolver 30. The rotary transformer 30 can receive the excitation voltage of the excitation signal to generate an induced electromotive force, detect the rotation of the motor, and transmit a first output signal to the feedback conditioning circuit 22 through a first line L1 and transmit a second output signal to the feedback conditioning circuit 22 through a second line L2. The feedback conditioning circuit 22 may decode the first output signal and the second output signal, and transmit the decoded first output signal and second output signal to the analog-to-digital conversion unit 12, so as to perform conversion from an analog signal to a digital signal on the decoded first output signal and second output signal through the analog-to-digital conversion unit 12, so that the digital signal processing apparatus 10 determines the rotation angle and the rotation speed of the motor according to the analog-to-digital converted signals. Wherein the first output signal and the second output signal are out of phase, e.g. 90 ° out of phase. Optionally, the first output signal is a sine signal and the second output signal is a cosine signal.

Fig. 3 is a waveform diagram of an output signal of a resolver, where an abscissa represents time and an ordinate represents a signal amplitude, according to an embodiment of the present invention, and fig. 3 schematically illustrates a waveform of an output signal of a resolver in normal operation, and illustrates a case where a first output signal S1 is a sine signal and a second output signal S2 is a cosine signal.

And S120, respectively determining the change conditions of the amplitude states of the first output signal and the second output signal within the set time.

The setting time may be set according to the fault tolerance time of the resolver, for example, when the fault tolerance time of the resolver is 100ms, the setting time may be greater than 100 ms. Alternatively, the setting time may be set in combination with the time when the amplitudes of the first output signal and the second output signal are zero and the fault allowable time of the resolver, for example, the setting time is greater than the time when the amplitudes of the first output signal and the second output signal are zero and is greater than the fault allowable time of the resolver.

Specifically, the amplitude states of the first output signal and the second output signal include amplitude magnitudes of the first output signal and the second output signal or amplitude ranges of the first output signal and the second output signal, and the change condition of the amplitude states of the first output signal and the second output signal in the set time may include whether the amplitude magnitudes or the amplitude states of the first output signal and the second output signal are changed in the set time and the number of times of the change. For example, the value ranges of the first output signal and the second output signal may be the same, the value ranges of the first output signal and the second output signal may be divided into a plurality of value intervals, within a set time, if the amplitude of the first output signal enters another value interval from one value interval, it may be determined that the amplitude state of the first output signal changes within the set time, each time the amplitude state of the first output signal changes within the set time, it may be recorded that the amplitude state of the first output signal changes once, and if the amplitude of the first output signal is always within one value interval, it is determined that the amplitude state of the first output signal does not change. Similarly, the change of the amplitude state of the second output signal in the set time can be determined.

And S130, detecting whether the transmission line of the first output signal and the transmission line of the second output signal have a disconnection fault according to the change condition of the amplitude states of the first output signal and the second output signal within a set time.

Referring to fig. 2, the transmission line of the first output signal may be a first line L1, and the transmission line of the second output signal may be a second line L2, and when the resolver does not have a disconnection fault, the amplitude states of the first output signal and the second output signal are continuously changed for a set time, and the number of times of the change is greater than a set number of times, which may be determined according to the frequencies of the first output signal and the second output signal. When the amplitude states of the first output signal and the second output signal are changed within the set time, it may be determined that the disconnection fault has not occurred in both the first line L1 and the second line L2. When the amplitude state of one of the first output signal and the second output signal is changed within the set time and the number of times of the change is greater than the set number of times and the amplitude state of the other output signal is not changed within the set time, it may be determined that one of the first line L1 and the second line L2 has a disconnection fault and the line in which the disconnection fault occurs is a line in which the amplitude state of the output signal is not changed within the set time. Alternatively, when the vehicle speed is low, there is also a case where the state of the amplitude of one of the first output signal and the second output signal is not changed, the state of the amplitude of the other output signal is changed within the set time, and the number of changes is less than the set number, so it is determined that the disconnection fault has not occurred in both the first line L1 and the second line L2 in this case.

According to the technical scheme of the embodiment of the invention, whether the transmission line of the first output signal and the transmission line of the second output signal have the disconnection fault or not is detected according to the change condition of the amplitude states of the first output signal and the second output signal of the rotary transformer in the set time, so that the disconnection fault detection of the rotary transformer is realized. The scheme can detect that one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault when the amplitude state of one of the first output signal and the second output signal changes within the set time, the change times are more than the set times, and the amplitude state of the other output signal does not change within the set time. And, through setting up the settlement time, help avoiding the problem that the fault maturation time is too short and arouse frequent parking among the prior art, even when resolver's output signal's frequency is higher, also can detect the broken string trouble according to the change condition of the amplitude state of first output signal and second output signal in the settlement time, help guaranteeing under the prerequisite of electric automobile normal work, promote resolver's broken string trouble detection's accuracy. In addition, the fault detection method of the rotary transformer provided by the embodiment of the invention can be executed by the existing control system of the rotary transformer, and is beneficial to reducing the fault detection cost.

On the basis of the foregoing scheme, optionally, step S110 specifically includes: the first output signal and the second output signal of the rotary transformer are sampled to determine an envelope signal of the first output signal and an envelope signal of the second output signal.

Specifically, the envelope signal of the first output signal is a signal corresponding to a wave curve tangent to at least one point in each wave curve of the first output signal, and similarly, the envelope signal of the second output signal is a signal corresponding to a wave curve tangent to at least one point in each wave curve of the second output signal.

On the basis of the above scheme, optionally, sampling the first output signal and the second output signal of the rotary transformer to determine the envelope signal of the first output signal and the envelope signal of the second output signal includes:

and S111, sampling the first output signal and the second output signal according to a set sampling frequency so as to acquire a set number of signal sampling points in each signal state judgment period of the first output signal and the second output signal.

The set sampling frequency is a frequency for sampling the first output signal and the second output signal. The signal state determination periods of the first output signal and the second output signal refer to a period preset for determining the amplitudes of the envelope signals of the first output signal and the second output signal, and a plurality of signal state determination periods can be included in the set time. Optionally, the set sampling frequency is set to be greater than the carrier frequency of the first output signal and the second output signal. The output signal of the rotary transformer carries a high frequency carrier, for example, the carrier frequency of the first output signal and the second output signal of the rotary transformer may be 5kHz or 10kHz, and for example, 10kHz is taken as an example, the sampling frequency may be set to a frequency above 10kHz, for example, 100 kHz. This has the advantage of facilitating acquisition of a corresponding signal point in each cycle of the first output signal and the second output signal, thereby determining values around the envelope signal of the first output signal and the second output signal.

And S112, taking the maximum value of the absolute values of the amplitudes of the signal sampling points of the first output signal in each signal state judgment period as the amplitude of the envelope signal of the first output signal in the period, and taking the maximum value of the absolute values of the amplitudes of the signal sampling points of the second output signal in each signal state judgment period as the amplitude of the envelope signal of the second output signal in the period.

Illustratively, taking the frequency of the first output signal and the second output signal of the resolver as 10kHz, the sampling frequency as 100kHz, and the number of the sampling points as 10 as an example, the first output signal and the second output signal are sampled according to 100kHz, 10 signal sampling points are obtained in each signal state determination period of the first output signal and the second output signal, the maximum value of the absolute values of the amplitude values of the 10 signal sampling points in each signal state determination period of the first output signal is determined, the amplitude value with the largest absolute value is taken as the amplitude value of the envelope signal of the first output signal in the period, the corresponding time of the signal point of the amplitude value is the sampling time, and the other signal sampling points are not used for determining the signal point of the envelope signal of the first output signal. By determining the maximum value of the absolute values of the amplitudes of the signal sampling points of the first output signal in each signal state judgment period, the corresponding amplitude of the envelope signal of the first output signal in each period of the first output signal can be determined, so that the envelope signal of the first output signal is ensured to include the amplitude of the first output signal in each period, and further, the complete waveform of the envelope signal of the first output signal can be determined. Similarly, the waveform of the envelope signal of the second output signal may be determined.

Optionally, the change condition of the amplitude state of the first output signal within the set time includes the number of changes of the amplitude state of the envelope signal of the first output signal within the set time; the change condition of the amplitude state of the second output signal in the set time comprises the change times of the amplitude state of the envelope signal of the second output signal in the set time.

For example, the envelope signals of the first output signal and the second output signal may have the same value range, the envelope signals of the first output signal and the second output signal may have a plurality of threshold values, the amplitude state of the envelope signal of the first output signal may be determined to change within a set time if the amplitude of the envelope signal of the first output signal changes from one threshold value to another threshold value within the set time, the amplitude state of the envelope signal of the first output signal may be recorded once each time the amplitude state of the envelope signal of the first output signal changes within the set time, and the number of changes of the amplitude state of the first output signal may be determined to be zero if the amplitude of the first output signal is always between the two threshold values. Similarly, the number of changes in the amplitude state of the envelope signal of the second output signal within the set time can be determined.

On the basis of the foregoing scheme, optionally, step S120 specifically includes:

and S121, determining that the amplitude state of the envelope signal of the first output signal changes when the amplitude of the envelope signal of the first output signal is changed from being larger than a first set threshold to being smaller than a second set threshold, or is changed from being smaller than the second set threshold to being larger than the first set threshold.

Wherein the first set threshold is greater than the second set threshold. For example, the first output signal and the second output signal have the same range of the envelope signal, the first set threshold is 80% of the amplitude of the envelope signal of the first output signal and the second output signal, and the second set threshold is 20% of the amplitude of the envelope signal of the first output signal and the second output signal.

For the sake of convenience of distinction, when the amplitude of the envelope signal of the first output signal is greater than a first set threshold, the state of the envelope signal of the first output signal is denoted as High, and when the amplitude of the envelope signal of the first output signal is less than a second set threshold, the state of the envelope signal of the first output signal is denoted as Low. When the amplitude of the envelope signal of the first output signal is changed from being larger than a first set threshold to being smaller than a second set threshold, the state of the envelope signal of the first output signal is changed from High to Low, and it can be determined that the amplitude state of the envelope signal of the first output signal is changed. When the amplitude of the envelope signal of the first output signal changes from being smaller than the second set threshold to being larger than the first set threshold, the state of the envelope signal of the first output signal changes from Low to High, and it is also possible to determine that the state of the amplitude of the envelope signal of the first output signal changes. And when the amplitude of the envelope signal of the first output signal is greater than or equal to a second set threshold and less than or equal to a first set threshold, determining that the amplitude state of the envelope signal of the first output signal is unchanged if the state of the envelope signal of the first output signal is between High and Low. Similarly, it can also be determined whether the amplitude state of the envelope signal of the second output signal has changed.

Alternatively, the first set threshold is smaller than a maximum value of magnitudes of the envelope signals of the first output signal and the envelope signals of the second output signal, the second set threshold is larger than a minimum value of magnitudes of the envelope signals of the first output signal and the envelope signals of the second output signal, and the first set threshold and the second set threshold differ by a set difference value. Wherein, the size of setting for the difference can set up as required. If the difference between the first set threshold and the second set threshold is too small, the signal can be continuously switched between the first set threshold and the second set threshold, and the signal state can be misjudged.

And S122, determining that the amplitude state of the envelope signal of the second output signal changes when the amplitude of the envelope signal of the second output signal is changed from being larger than a first set threshold to being smaller than a second set threshold, or is changed from being smaller than the second set threshold to being larger than the first set threshold.

And S123, respectively calculating the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in a set time.

Fig. 4 is a waveform diagram of an envelope signal of an output signal of a resolver, where fig. 4 schematically illustrates a waveform of the envelope signal of the output signal of the resolver during normal operation, and specifically illustrates a variation number curve of an amplitude state of the envelope signal S11 of the first output signal and a variation number curve of the envelope signal S21 of the second output signal corresponding to the envelope signal S11 of the first output signal and the envelope signal S21 of the second output signal when the first output signal is a sine signal and the second output signal is a cosine signal. Illustratively, when the first set threshold is 0.8 and the second set threshold is 0.2, the number of changes of the amplitude state of the envelope signal S11 of the first output signal within the set time is 5.

Fig. 5 is a waveform diagram of an envelope signal of an output signal of another resolver according to an embodiment of the present invention, where fig. 5 schematically shows a signal waveform when a transmission line of a first output signal of the resolver is disconnected and a transmission line of a second output signal of the resolver normally operates, and the envelope signal S21 of the second output signal in fig. 4 and 5 is the same. Illustratively, still taking the first set threshold of 0.8 and the second set threshold of 0.2 as an example, the number of changes of the amplitude state of the envelope signal S21 of the second output signal within the set time is 5 times. Since the transmission line of the first output signal is broken, the amplitude of the first output signal in the set time is kept constant, and the amplitude of the envelope signal of the first output signal is also kept constant, and the waveform of the envelope signal of the first output signal, which is not specifically shown in fig. 5, can be regarded as a straight line with a constant amplitude, for example, a straight line with zero amplitude.

Optionally, step S130 specifically includes: and determining that one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault when the absolute value of the difference between the change times of the amplitude states of the envelope signals of the first output signal and the second output signal within the set time is greater than the set time.

The set times can be set according to requirements. When the resolver normally operates, the number of times of change in the amplitude state of the envelope signal of the first output signal and the second output signal within a set time is close to 1, for example, when the set number of times is 1, the absolute value of the difference between the number of times of change in the amplitude state of the envelope signal of the first output signal and the envelope signal of the second output signal within 20ms is less than or equal to 1. Illustratively, in conjunction with fig. 4 and 5, when the transmission line of the first output signal has not been broken within 20ms, the number of times of change of the amplitude state of the envelope signal S11 of the first output signal within the set time is 5 (see fig. 4), and when the transmission line of the second output signal has not been broken within the set time, the number of times of change of the amplitude state of the envelope signal S21 of the second output signal within the set time is 5 (see fig. 5), and the difference between the two numbers of times of change is zero. If one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault, the number of times of change of the amplitude state of the envelope signal of one of the first output signal and the second output signal is significantly less than that of the other within the set time, and therefore it is possible to determine that one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault when the absolute value of the difference between the number of times of change of the amplitude state of the envelope signal of the first output signal and the envelope signal of the second output signal within 20ms is greater than 1 time.

On the basis of the above scheme, optionally, the resolver is used for detecting a rotation speed of a motor in the electric vehicle, and the magnitude of the set number of times is in positive correlation with the magnitude of the rotation speed of the motor. The higher the rotation speed of the motor is, the higher the frequency of the envelope signals of the first output signal and the second output signal is, the more the number of changes of the amplitude states of the envelope signals of the first output signal and the second output signal is, and therefore, the greater the set number can be set to improve the accuracy of the disconnection fault detection. Alternatively, the magnitude of the set number of times is positively correlated with the failure maturation time of the transmission line of the first output signal and the transmission line of the second output signal. The failure maturity time is the time when the disconnection failure is developed to maturity and can be identified, the longer the failure maturity time is, the larger the proportion of the failure maturity time in the set time of signal sampling is, and when the disconnection failure occurs in any one of the transmission line of the first output signal and the transmission line of the second output signal, the larger the difference between the change times of the amplitude states of the envelope signals of the first output signal and the second output signal is, so that the set times can be set to be larger, and the accuracy of the detection of the disconnection failure is improved. Optionally, the set number of times is positively correlated with the number of pole pairs of the resolver. The more the number of pole pairs of the resolver is, the higher the accuracy of the first output signal and the second output signal is, and when a disconnection fault occurs in any one of the transmission line of the first output signal and the transmission line of the second output signal, the larger the difference between the number of changes in the amplitude state of the envelope signal of the first output signal and the envelope signal of the second output signal is, so that the larger the set number can be set to improve the accuracy of the detection of the disconnection fault.

Alternatively, when one of the numbers of changes in the amplitude state of the envelope signals of the first output signal and the second output signal within the set time is zero and the other is greater than the set number, it is determined that one of the transmission line of the first output signal and the transmission line of the second output signal is a line in which a disconnection fault has occurred, and the transmission line of the signal in which the number of changes in the amplitude state of the envelope signal is zero is a line in which a disconnection fault has occurred.

Referring to fig. 5, for example, when the transmission line of the first output signal of the resolver is disconnected, the transmission line of the second output signal is normally operated, and the set number of times is 1, the amplitude of the first output signal and the envelope signal thereof is kept near zero, the amplitude of the envelope signal of the first output signal is always smaller than the second set threshold, and the state of the envelope signal of the first output signal is kept Low. And the amplitude state of the envelope signal S21 of the second output signal changes 5 times within the set time, which is greater than the set time. Therefore, it is possible to determine that a disconnection fault has occurred in one of the transmission line of the first output signal and the transmission line of the second output signal when the number of changes of the amplitude state of the envelope signal of the first output signal and the second output signal within the set time is one of zero and the other is greater than the set number, and the transmission line of the signal in which the number of changes of the amplitude state of the envelope signal is zero is a line in which the disconnection fault has occurred. The present embodiment can detect a disconnection fault of the signal transmission line based on the number of changes in the amplitude states of the envelope signals of the first output signal and the second output signal within a set time, and can accurately detect a disconnection fault of the signal transmission line even when the frequency of the output signal of the resolver is high.

Optionally, step S130 may further include: and when the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in the set time are both larger than zero, determining that the transmission line of the first output signal and the transmission line of the second output signal both work normally. Specifically, when the number of times of change of the amplitude states of the envelope signals of the first output signal and the second output signal within the set time is greater than zero, it is determined that the states of the envelope signals of the first output signal and the second output signal are both changed, and therefore it is determined that the transmission line of the first output signal and the transmission line of the second output signal both operate normally.

Optionally, step S130 may further include: and when one of the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in the set time is zero and the other is less than the set time, determining that the transmission line of the first output signal and the transmission line of the second output signal both work normally. For example, when the vehicle speed is low, there is a case where the sampling signals of the first output signal and the second output signal within the set time are few, and therefore, there is a case where one of the number of changes of the amplitude states of the envelope signals of the first output signal and the second output signal within the set time is zero, and the other is smaller than the set number and is not zero (the value of the set number in this case is greater than 1), and therefore, it is possible to determine that both the transmission line of the first output signal and the transmission line of the second output signal are operating normally, so as to avoid the occurrence of a wire break fault misjudgment.

Referring to fig. 2, on the basis of the above schemes, the method for detecting a fault of a resolver further includes: and detecting whether the transmission line of the first output signal, the transmission line of the second output signal and the transmission line of the excitation signal input by the rotary transformer have line break faults or not according to the amplitudes of the first output signal and the second output signal in the set time.

Illustratively, the digital signal processing apparatus 10 generates a PWM signal by the pulse width modulation signal generating unit 11, and the excitation conditioning circuit 121 converts the PWM signal into an excitation signal and transmits it to the resolver 30, and the transmission line of the excitation signal may be the third line L3 shown in fig. 2. Since the amplitudes of the first output signal and the second output signal are related to the states of the first line L1, the second line L2, and the third line L3, it is possible to detect whether or not a disconnection fault has occurred in the transmission line of the first output signal, the transmission line of the second output signal, and the transmission line of the excitation signal input to the resolver, based on the amplitudes of the first output signal and the second output signal within a set time.

Optionally, when the amplitudes of the first output signal and the second output signal are both zero within the set time, it is determined that the transmission line of the excitation signal has a disconnection fault, or the transmission line of the first output signal and the transmission line of the second output signal have a disconnection fault at the same time. Specifically, when the disconnection fault occurs in the third line L3, the resolver does not output, the amplitudes of the first output signal and the second output signal are both zero within the set time, and when the disconnection fault occurs in both the first line L1 and the second line L2, the amplitudes of the first output signal and the second output signal are also both zero within the set time, so that when the electric vehicle is running normally and the amplitudes of the first output signal and the second output signal are both zero within the set time, it is determined that the disconnection fault occurs in the third line L3, or the disconnection fault occurs in both the first line L1 and the second line L2.

Fig. 6 is a flowchart of another fault detection method for a resolver according to an embodiment of the present invention, and on the basis of the foregoing embodiments, the present embodiment further optimizes the fault detection method for the resolver. As shown in fig. 6, the method for detecting a fault of a resolver may specifically include:

s210, sampling a first output signal and a second output signal of the rotary transformer at a set frequency.

The first output signal is a sine signal, and the second output signal is a cosine signal. The set frequency is greater than the carrier frequency of the first output signal and the second output signal, and each signal state judgment period of the first output signal and the second output signal comprises a set number of signal sampling points.

S220, determining the amplitude of the envelope signal of the corresponding output signal in each signal state judgment period according to the maximum value of the absolute values of the amplitudes of the signal sampling points of the first output signal and the second output signal in the period.

Specifically, the maximum value of the absolute values of the amplitudes of the signal sampling points of the first output signal in each period is taken as the amplitude of the envelope signal of the first output signal in the period, and the maximum value of the absolute values of the amplitudes of the signal sampling points of the second output signal in each period is taken as the amplitude of the envelope signal of the second output signal in the period.

And S230, calculating the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in a set time according to the amplitude of the envelope signals of the first output signal and the second output signal and the change condition between a first set threshold and a second set threshold.

Specifically, it is determined that the state of the amplitude of the envelope signal of the first output signal changes when the amplitude of the envelope signal of the first output signal changes from being greater than a first set threshold to being less than a second set threshold, or from being less than the second set threshold to being greater than the first set threshold. And determining that the amplitude state of the envelope signal of the second output signal changes when the amplitude of the envelope signal of the second output signal changes from being larger than a first set threshold to being smaller than a second set threshold or from being smaller than the second set threshold to being larger than the first set threshold.

And S240, counting the sampling time through a timing counter.

The timing counter is used for recording the current sampling time. Illustratively, in the process of sampling the first output signal and the second output signal of the rotary transformer, the count value of the timing counter is increased by 1 every fixed time interval until the sampling time reaches a set time for identifying the disconnection fault, for example, the set time is 200 ms. According to the accumulated value of the count value of the timing counter, whether the current sampling time reaches the set time for identifying the disconnection fault can be determined.

And S250, judging whether the sampling time reaches the set time.

If the sampling time reaches the set time, executing step S260; and if the sampling time does not reach the set time, ending the process.

Still taking the setting time of 200ms as an example, it is determined whether the current sampling time reaches the setting time or not according to the accumulated value of the count value of the timer counter, if the sampling time reaches 200ms, the subsequent disconnection fault determination process is continued, and if the sampling time does not reach 200ms, for example, if the electric vehicle stops when the sampling time does not reach 200ms, the disconnection fault does not need to be continuously detected, so the detection of the disconnection fault can be finished.

And S260, judging whether the change times of the amplitude states of the envelope signals of the first output signal and the second output signal in the set time are zero or not, and the other change times is more than the set time.

The set number of times can be proportional to the rotation speed of a motor in the electric automobile, the fault maturation time of a transmission line and the number of pole pairs of a rotary transformer.

If one of the changing times of the amplitude states of the envelope signals of the first output signal and the second output signal in the set time is zero, and the other is greater than the set time, executing S270; if the number of times of change of the amplitude states of the envelope signals of the first output signal and the second output signal within the set time is zero, or one of the first output signal and the second output signal is zero and the other is less than or equal to the set time, or the number of times of change of the amplitude states of the envelope signals of the first output signal and the second output signal within the set time is non-zero, S280 is executed.

And S270, determining that one of the transmission line of the first output signal and the transmission line of the second output signal has a disconnection fault, and adding one to the count value of the state change counter.

The transmission line of the signal with the zero number of changes in the amplitude state of the envelope signal is a line with a disconnection fault. When the transmission line has a disconnection fault, the count value of the state change counter can be increased by 1 so as to record the disconnection fault.

And S280, clearing the count value of the state change counter.

The count value of the state change counter may be cleared when the transmission line of the first output signal and the transmission line of the second output signal are not disconnected.

And S290, clearing the count value of the timing counter.

Specifically, each time the disconnection fault detection of the transmission line is completed, the count value of the timing counter may be cleared, so as to continue sampling of the first output signal and the second output signal in the next period and the disconnection fault detection, and record the set time for identifying the disconnection fault.

The present embodiment can detect a disconnection fault of the signal transmission line based on the number of changes in the amplitude states of the envelope signals of the first output signal and the second output signal within a set time, and can accurately detect a disconnection fault of the signal transmission line even when the frequency of the output signal of the resolver is high.

The embodiment of the invention also provides a fault detection device of the rotary transformer, and the device can execute the fault detection method of the rotary transformer in any embodiment. Fig. 7 is a schematic block diagram of a fault detection apparatus of a resolver according to an embodiment of the present invention, where as shown in fig. 7, the fault detection apparatus of the resolver includes: a signal acquisition module 310, a change condition determination module 320, and a disconnection fault detection module 330.

The signal acquisition module 310 is configured to acquire a first output signal and a second output signal of the resolver; wherein the first output signal and the second output signal are in different phases;

the change condition determining module 320 is configured to determine change conditions of the amplitude states of the first output signal and the second output signal within a set time respectively;

the disconnection fault detection module 330 is configured to detect whether a disconnection fault occurs in the transmission line of the first output signal and the transmission line of the second output signal according to a change condition of the amplitude states of the first output signal and the second output signal within a set time.

The resolver fault detection apparatus according to the embodiment of the present invention may perform the resolver fault detection method according to any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the performed method, which are not described again.

The embodiment of the invention also provides the electronic equipment. Fig. 8 is a schematic structural diagram of a terminal according to an embodiment of the present invention. FIG. 8 illustrates a block diagram of an exemplary device 412 suitable for use in implementing embodiments of the present invention. The device 412 shown in fig. 8 is only an example and should not impose any limitation on the functionality or scope of use of embodiments of the present invention.

As shown in fig. 8, the device 412 is in the form of a general purpose device. The components of device 412 may include, but are not limited to: one or more processors 416, a storage device 428, and a bus 418 that couples the various system components including the storage device 428 and the processors 416.

Bus 418 represents one or more of any of several types of bus structures, including a memory device bus or memory device controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, such architectures include, but are not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

Device 412 typically includes a variety of computer system readable media. Such media can be any available media that is accessible by device 412 and includes both volatile and nonvolatile media, removable and non-removable media.

Storage 428 may include computer system readable media in the form of volatile Memory, such as Random Access Memory (RAM) 430 and/or cache Memory 432. The device 412 may further include other removable/non-removable, volatile/nonvolatile computer system storage media. By way of example only, storage system 434 may be used to read from and write to non-removable, nonvolatile magnetic media (not shown in FIG. 8, and commonly referred to as a "hard drive"). Although not shown in FIG. 8, a magnetic disk drive for reading from and writing to a removable, nonvolatile magnetic disk (e.g., a "floppy disk") and an optical disk drive for reading from or writing to a removable, nonvolatile optical disk such as a Compact disk Read-Only Memory (CD-ROM), Digital Video disk Read-Only Memory (DVD-ROM) or other optical media may be provided. In these cases, each drive may be connected to bus 418 by one or more data media interfaces. Storage 428 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.

A program/utility 440 having a set (at least one) of program modules 442 may be stored, for instance, in storage 428, such program modules 442 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which examples or some combination thereof may comprise an implementation of a network environment. The program modules 442 generally perform the functions and/or methodologies of the described embodiments of the invention.

The device 412 may also communicate with one or more external devices 414 (e.g., keyboard, pointing terminal, display 424, etc.), with one or more terminals that enable a user to interact with the device 412, and/or with any terminals (e.g., network card, modem, etc.) that enable the device 412 to communicate with one or more other computing terminals. Such communication may occur via input/output (I/O) interfaces 422. Further, the device 412 may also communicate with one or more networks (e.g., a Local Area Network (LAN), Wide Area Network (WAN), and/or a public Network, such as the internet) via the Network adapter 420. As shown in FIG. 8, network adapter 420 communicates with the other modules of device 412 via bus 418. It should be appreciated that although not shown in the figures, other hardware and/or software modules may be used in conjunction with the device 412, including but not limited to: microcode, end drives, Redundant processors, external disk drive Arrays, RAID (Redundant Arrays of Independent Disks) systems, tape drives, and data backup storage systems, among others.

The processor 416 executes various functional applications and data processing by executing programs stored in the storage device 428, for example, implementing a method for detecting a fault of a resolver according to an embodiment of the present invention, the method including:

collecting a first output signal and a second output signal of a rotary transformer;

and detecting whether the transmission line of the first output signal and the transmission line of the second output signal have disconnection faults or not according to the change condition of the amplitude states of the first output signal and the second output signal within the set time.

An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements a method for detecting a fault of a resolver, where the method includes:

Computer storage media for embodiments of the invention may employ any combination of one or more computer-readable media. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or terminal. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider).

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method of fault detection for a rotary transformer, comprising:

2. The resolver fault detection method according to claim 1, wherein the first output signal is a sine signal and the second output signal is a cosine signal.

3. The resolver fault detection method according to claim 1 or 2, wherein acquiring the first output signal and the second output signal of the resolver comprises:

4. The method of claim 3, wherein sampling a first output signal and a second output signal of a resolver to determine envelope signals of the first output signal and the second output signal comprises:

5. The resolver fault detection method according to claim 4, wherein the set sampling frequency is greater than a carrier frequency of the first output signal and the second output signal.

6. The resolver fault detection method according to claim 1 or 2, wherein the change in the amplitude state of the first output signal within a set time includes the number of times the amplitude state of the envelope signal of the first output signal changes within the set time; the change condition of the amplitude state of the second output signal in a set time comprises the change times of the amplitude state of the envelope signal of the second output signal in the set time.

7. The method for detecting the fault of the rotary transformer according to claim 6, wherein the step of determining the change condition of the amplitude states of the first output signal and the second output signal within a set time respectively comprises the steps of:

8. The resolver fault detection method according to claim 7, wherein the first set threshold is smaller than a maximum value of magnitudes of the envelope signals of the first and second output signals, the second set threshold is larger than a minimum value of magnitudes of the envelope signals of the first and second output signals, and the first and second set thresholds differ by a set difference value.

9. The resolver fault detection method according to claim 6, wherein detecting whether or not a disconnection fault has occurred in the transmission line of the first output signal and the transmission line of the second output signal based on a change in the amplitude state of the first output signal and the second output signal within the set time includes:

10. The method of claim 9, wherein the resolver is used to detect a rotation speed of a motor in an electric vehicle, and the set number of times is positively correlated with the rotation speed of the motor; or the set times are positively correlated with the fault maturation time of the transmission line of the first output signal and the transmission line of the second output signal; or the set times are positively correlated with the number of pole pairs of the rotary transformer.

11. The resolver fault detection method according to claim 9, wherein when one of the numbers of changes in the amplitude state of the envelope signals of the first output signal and the second output signal within the set time is zero and the other is greater than the set number, it is determined that a disconnection fault has occurred in one of the transmission line of the first output signal and the transmission line of the second output signal, and the transmission line of the signal for which the number of changes in the amplitude state of the envelope signal is zero is a line in which the disconnection fault has occurred.

12. The resolver fault detection method according to claim 9, wherein whether or not a disconnection fault occurs in the transmission line of the first output signal and the transmission line of the second output signal is detected based on a change in the amplitude state of the first output signal and the second output signal within the set time, further comprising:

13. The resolver fault detection method according to claim 9, wherein whether or not a disconnection fault occurs in the transmission line of the first output signal and the transmission line of the second output signal is detected based on a change in the amplitude state of the first output signal and the second output signal within the set time, further comprising:

14. The resolver fault detection method according to claim 1 or 2, further comprising:

15. The resolver fault detection method according to claim 14, wherein when the amplitudes of the first output signal and the second output signal are both zero within the set time, it is determined that the disconnection fault has occurred in the transmission line of the excitation signal, or the disconnection fault has occurred in both the transmission line of the first output signal and the transmission line of the second output signal.

16. A fault detection device for a rotary transformer, comprising: