Method and system for identifying rotating speed signal of special tooth

Abstract

The invention discloses a method and a system for identifying a rotating speed signal of a special tooth. The transconductance amplification circuit receives a rotating speed signal containing a special tooth, converts the rotating speed signal into a current signal, converts the current signal into a voltage signal and outputs the voltage signal to the bias amplification circuit; the bias amplification circuit receives the first bias reference voltage and outputs a single-end voltage signal to the rectification follower circuit; the rectification following circuit also receives the first bias reference voltage, completes full-wave rectification and amplitude adjustment, outputs a first signal to the closed-loop control circuit, and outputs a second signal to the waveform judgment circuit; the waveform judgment circuit receives the third bias reference voltage, completes identification of a special tooth signal in the second signal output signal, and outputs a pulse signal indicating the position of a special tooth; the closed-loop control circuit receives the second bias reference voltage, integrates the first signal output and then outputs a direct current signal to control the amplification coefficient of the transconductance amplification circuit. According to the invention, the special tooth waveform in the broadband wide rotating speed signal can be accurately identified in real time.

Description

Technical Field

[0001] The invention relates to the field of aircraft engine health management, and in particular to a method and system for automatically gain controlling and identifying special gear speed signals. Background Art

[0002] As a high-end electromechanical product, aircraft engines are complex in structure, technology-intensive and expensive. Aircraft engine health management (PHM) is a key technology to improve aircraft engine availability, reduce maintenance costs and ensure navigation safety.

[0003] In the aircraft engine health management system, rotor phase information is very important and is one of the basic information for completing rotor balancing, vibration analysis and other tasks. At present, rotor phase information is mainly obtained through specially processed rotor tachometer sound wheels. The N teeth of the tachometer sound wheel contain one to three special teeth (i.e., special tooth shapes such as high teeth and low teeth whose sensing signals are different from those of conventional teeth). When the special (high / low) teeth pass through the speed sensor, the sensing signal waveform generated by the sensor is different from that of other teeth (the waveform amplitude is significantly higher or lower than the waveform generated by ordinary teeth). By real-time identification of the waveform of the special teeth and recording it as the rotor reference phase mark in the vibration signal data, the vibration signal phase information can be obtained, providing the necessary input for the rotor dynamic balancing test processing. For example, CN109668735A discloses a method for determining an engine rotor phase reference, comprising: receiving a waveform signal of a current tooth; determining a high tooth feature of the waveform signal of the current tooth based on the waveform signal of the current tooth; obtaining the high tooth features of the waveform signals of the first N-1 consecutive teeth; and determining that the current tooth is a high tooth when the high tooth feature of the waveform signal of the current tooth is greater than the high tooth features of the waveform signals of the first N-1 teeth.

[0004] The key to timely and accurate determination of the rotor phase is to be able to accurately and timely identify the special tooth waveform in the speed signal. However, since the signal waveform generated by the speed sensor is related to the speed and the gap between the sensor sensing part and the tone wheel teeth, the amplitude of the speed signal is not constant, but changes with the speed change and the gap change caused by rotor vibration. The speed signal amplitude can differ by up to dozens of times. At low speeds, the speed signal amplitude is small, which makes it difficult to identify the special tooth waveform.

[0005] Therefore, there is an urgent need for a method and system that can accurately and real-timely identify special tooth waveforms in broadband and wide-width speed signals. Summary of the invention

[0006] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter; nor is it intended to be used to determine or limit the scope of the claimed subject matter.

[0007] The present invention provides a wide-band and wide-width speed signal conditioning circuit system containing special tooth signals and a method for real-time identification of special tooth signals. By adjusting the signal waveform through closed-loop automatic gain control, the high / short tooth waveform position in the speed signal can be accurately identified in real time.

[0008] A conditioning circuit system for identifying a special tooth speed signal according to the present invention comprises:

[0009] A transconductance amplifier circuit is used to receive a speed signal containing special teeth and convert it into a current signal for output; a bias amplifier circuit is used to receive a first bias reference voltage and a voltage signal converted from the current signal from the transconductance amplifier circuit through a grounding resistor, and output a single-ended voltage signal; a rectifier follower circuit is used to receive the first bias reference voltage and the single-ended voltage signal from the bias amplifier circuit, complete full-wave rectification and amplitude adjustment, and output a first signal and a second signal; a closed-loop control circuit is used to receive a second bias reference voltage and a first signal from the rectifier follower circuit, integrate the first signal and output a DC signal for controlling the amplification factor of the transconductance amplifier circuit; and a waveform judgment circuit is used to receive a third bias reference voltage and a second signal from the rectifier follower circuit, complete the identification of the special tooth signal in the second signal, and output a pulse signal indicating the position of the special tooth signal.

[0010] The closed-loop control circuit further includes a UI conversion circuit and an integration circuit. The integration circuit receives a second bias reference voltage and a first signal from the rectifier-follower circuit to integrate the first signal and convert it into a DC signal by the UI conversion circuit.

[0011] The second bias reference voltage is 125% of the first bias reference voltage. When the special tooth is a high tooth, the third bias reference voltage is set according to the maximum value of the ordinary tooth and the minimum value of the high tooth. When the special tooth is a low tooth, the third bias reference voltage is set according to the minimum value of the ordinary tooth and the maximum value of the low tooth. Preferably, the first bias reference voltage is 2V, the second bias reference voltage is 2.5V, and the third bias reference voltage is 2.85V.

[0012] A method for identifying a special tooth speed signal according to the present invention comprises:

[0013] A speed signal containing a special tooth signal is received by a transconductance amplifier circuit and converted into a current signal; the current signal is converted into a voltage, and a single-ended voltage signal is generated by applying a first bias reference voltage; the first bias reference voltage is used to complete full-wave rectification and amplitude adjustment to generate a first signal and a second signal; a third bias reference voltage is used to complete the recognition of the special tooth signal in the second signal, and a pulse signal indicating the position of the special tooth signal is output.

[0014] The present invention further includes using a second bias reference voltage to integrate the first signal, and outputting a direct current signal as an amplification factor of the transconductance discharge circuit for negative feedback gain control of the transconductance amplifier circuit.

[0015] These and other features and advantages will become apparent by reading the following detailed description and by reference to the associated drawings.It is to be understood that the foregoing general description and the following detailed description are illustrative only and are not restrictive of the aspects of what is claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described in more detail below with reference to specific embodiments shown in the accompanying drawings.

[0017] Figure 1 is a circuit diagram of a conditioning circuit system for automatically gain controlling and identifying high / low gear speed signals according to the present invention;

[0018] Figure 2 yes Figure 1 Schematic diagram of special tooth identification in the conditioning circuit system;

[0019] Figure 3 yes Figure 2 The integral closed-loop control principle block diagram of the closed-loop control circuit in;

[0020] Figure 4 is a schematic diagram of automatic gain control input / output;

[0021] Figure 5 This is a simulation diagram of high gear signal;

[0022] Figure 6 This is a simulation diagram of the dwarf tooth signal. DETAILED DESCRIPTION

[0023] The present invention will be described in more detail below by referring to the specific embodiments shown in the accompanying drawings. By reading the detailed description of the specific embodiments below, various advantages and benefits of the present invention will become clear to those of ordinary skill in the art. However, it should be understood that the present invention can be implemented in various forms and should not be limited by the various embodiments set forth herein. The following embodiments are provided in order to be able to more thoroughly understand the present invention. Unless otherwise stated, the technical terms or scientific terms used in this application should be the common meanings understood by those skilled in the art to which this application belongs.

[0024] Figure 1 and Figure 2 It is a circuit diagram of a conditioning circuit system for automatically gain controlling and identifying high / low tooth speed signals according to the present invention and a special tooth identification principle diagram. Figure 2It is shown in the figure that the conditioning circuit system includes the following modules: a transconductance amplifier circuit 1, a bias amplifier circuit 2, a rectifier follower circuit 3, a closed-loop control circuit 4 and a waveform judgment circuit 5. Figure 1 Yes and Figure 2 The corresponding exemplary circuit diagram, in which the parameter values ​​of each component are marked are preferred and should not be shown as limiting. Those skilled in the art can understand that they can be flexibly adjusted according to different configurations of engines. Figure 2 Other values ​​of the functions of each module are also conceivable.

[0025] The connection relationship between the modules of the conditioning circuit system of the present invention is as follows:

[0026] One input end of the transconductance amplifier circuit 1 is connected to a speed signal including a high / low gear signal, and an output end of the transconductance amplifier circuit 1 is connected to an input end of a bias amplifier circuit 2;

[0027] Another input terminal of the bias amplifier circuit 2 is simultaneously connected to the bias reference voltage Uref_b input, and the output terminal of the bias amplifier circuit 2 is connected to an input terminal of the rectifier follower circuit 3;

[0028] Another input terminal of the rectifier follower circuit 3 is simultaneously connected to the bias reference voltage Uref_b input, a first output terminal of the rectifier follower circuit 3 is connected to the input terminal of the closed-loop control circuit 4, and a second output terminal of the rectifier follower circuit 3 is connected to an input terminal of the waveform judgment circuit 5;

[0029] Figure 3 It is further shown that the closed-loop control circuit 4 includes a UI conversion circuit 42 and an integration circuit 41. One input terminal of the integration circuit 41 is connected to the first output terminal of the rectifier follower circuit 3, and the other input terminal of the integration circuit 41 is simultaneously connected to the bias reference voltage Uref_b+ input, the output terminal of the integration circuit 41 is connected to the input terminal of the UI conversion circuit 42, and the output terminal of the UI conversion circuit 42 is connected to the other input terminal of the transconductance amplifier circuit 1;

[0030] One input end of the waveform judgment circuit 5 is connected to the second output end of the rectifier follower circuit 3, and the other input end of the waveform judgment circuit 5 is simultaneously connected to the bias reference voltage Uref_c input, and the waveform judgment circuit 5 outputs a high-low tooth identification signal.

[0031] The method for automatic gain control to identify special tooth speed signal of the present invention comprises the following steps:

[0032] The speed signal (i.e., differential voltage signal) containing high / low teeth is input into the transconductance amplifier circuit 1. The amplification factor of the transconductance amplifier circuit 1 is determined by the bias current I from the closed-loop control circuit 4. b Control, transconductance amplifier circuit 1 converts the input differential voltage signal into a current signal Io Output, current signal I o The voltage is converted into voltage by grounding resistor R19, and the DC in the signal is eliminated by capacitor C3 before being sent to bias amplifier circuit 2;

[0033] The bias amplifier circuit 2 has a bias reference voltage U ref_b Input( Figure 1 In the embodiment of U ref_b The value is 2v, U refb The value of determines the effective value of the output signal of the rectifier follower circuit 3), after receiving the voltage signal from the transconductance amplifier circuit 1, it outputs a single-ended voltage signal U with a bias voltage Uref_b added. o It should be noted that after the bias amplifier circuit 2 adds the bias to the input signal, the entire output signal is positive. o Input to the rectifier follower circuit 3 through resistor R25;

[0034] Because U o The bias is U ref_b AC signal, so the rectifier follower circuit 3 also has a bias reference voltage of U ref_b The input is used to eliminate the error caused by the DC component. When receiving the output single-ended voltage signal U from the bias amplifier circuit 2 o After that, the rectifier follower circuit 3 completes the full-wave rectification and amplitude adjustment. The full-wave rectification raises the negative half cycle of the signal to the positive half cycle. Figure 1 In the embodiment of the present invention, the signal peak value is controlled to be around 3V. The first signal U of the rectifier follower circuit 3 f Input closed-loop control circuit 4, the output waveform example is in the attached Figure 4 It is shown in Figure 4 The automatic gain rectifier circuit in is equivalent to the aforementioned transconductance amplifier circuit 1+bias amplifier circuit 2+rectifier follower circuit 3+closed-loop control circuit 4. Figure 4 The hysteresis comparison circuit in is equivalent to the aforementioned waveform judgment circuit 5;

[0035] The integrator circuit 41 in the closed-loop control circuit 4 has a bias reference voltage U ref_b+ Input, reference voltage U ref_b+ The setting is U ref_b 125%, the integration circuit 41 converts the input signal U f The output signal after integration is approximately the DC signal I b , DC signal I b It is the negative feedback of the entire circuit, which is used for the negative feedback gain control of the transconductance amplifier circuit 1, thereby completing the entire gain closed-loop control. Figure 1 In the embodiment of U ref_b+ The value is 2.5v, slightly higher than U ref_b(2v), is used to prevent U f When the signal amplitude rises too fast, the circuit can output normally.

[0036] The second signal U of the rectifier follower circuit 3 c Input waveform judgment circuit 5, waveform judgment circuit 5 has a comparison reference voltage U ref_c The input (in Figure 1 In the embodiment, the value is 2.85V), and the identification of high / dwarf teeth and normal teeth is realized through the voltage comparison function, that is, according to the comparison reference voltage U ref_c Complete U c Identify the high / low tooth signal in the signal and output a pulse signal indicating the location of the high / low tooth signal. When the special tooth is a high tooth, U ref_c The setting is based on the following: when the speed signal changes, the high gear and the ordinary gear maintain a fixed ratio, and the reference voltage U ref_c By setting it to be greater than the maximum value of ordinary teeth and less than the minimum value of high teeth, high / low teeth can be identified from ordinary teeth. Generally, the amplitude of high teeth is 20% higher than that of ordinary teeth. Figure 1 In the embodiment, the peak value of the high-tooth is around 3V, and the peak value of the ordinary tooth is around 2.5V, so U ref_c Set to 2.85v. When the special gear is a short gear, U ref_c The setting of is based on the same principle and is set according to the minimum value of the ordinary teeth and the maximum value of the short teeth. A person skilled in the art can understand that the comparison reference voltage U ref_c It can be flexibly adjusted according to engines of different configurations.

[0037] Attached Figure 5 and Figure 6 The result of simulating the speed signal conditioning circuit system containing high / low tooth signals using simulation software is shown.

[0038] It can be seen that the output signal can quickly and accurately indicate the location of the high tooth or short tooth signal. When a high tooth or short tooth signal appears, the output signal is low level, and the output signal corresponding to the normal tooth signal is high level, and the output result is stable. This shows that the speed signal conditioning circuit containing high / short tooth signals can accurately and stably identify high / short tooth signals.

[0039] The present invention realizes gain control of a speed signal with wide-band and wide-amplitude variation based on a transconductance amplifier; realizes closed-loop feedback of a stable speed signal based on an integral loop feedback; realizes conditioning of the speed signal based on a full-wave rectifier circuit; adjusts the signal waveform through closed-loop compensation, adjusts the amplitude of the common tooth waveform to be consistent, and at the same time determines the difference between the special tooth waveform and the common tooth waveform, thereby improving the accuracy of special tooth waveform recognition.

[0040] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application.

Claims

1. A conditioning circuit system for identifying a special tooth speed signal, comprising: The transconductance amplifier circuit (1) is used to receive the speed signal containing the special tooth and convert it into a current signal (I o ) output; A bias amplifier circuit (2) is used to receive a first bias reference voltage (U ref_b ) and the current signal (I o ) is converted by grounding resistance and outputs a single-ended voltage signal (U o ); A rectifier-follower circuit (3) is used to receive the first bias reference voltage (U ref_b ) and a single-ended voltage signal (U o ), complete full-wave rectification and amplitude adjustment, and output the first signal (U f ) and the second signal (U c ); A closed-loop control circuit (4) is used to receive a second bias reference voltage (U ref_b+ ) and the first signal (U f ), the first signal (U f ) is integrated and then output as a DC signal (I b ), used to control the amplification factor of the transconductance amplifier circuit (1); as well as A waveform determination circuit (5) is used to receive a third bias reference voltage (U ref_c ) and the second signal (U c ), complete the second signal (U c ) signal, and output a pulse signal indicating the position of the special tooth signal.

2. The conditioning circuit system according to claim 1, characterized in that: The second bias reference voltage (U ref_b+ ) is the first bias reference voltage (U ref_b ) of 125%.

3. The conditioning circuit system according to claim 1, wherein: The closed-loop control circuit (4) further comprises a UI conversion circuit (42) and an integration circuit (41), wherein the integration circuit receives a second bias reference voltage (U ref_b+ ) and the first signal (U f ) for converting the first signal (U f ) is integrated and converted into the DC signal (I b ).

4. The conditioning circuit system according to claim 1, wherein: The first bias reference voltage (U ref_b ) is 2v, the second bias reference voltage (U ref_b+ ) is 2.5v, the third bias reference voltage (U ref_c ) is 2.85v.

5. The conditioning circuit system according to claim 1, wherein: When the special tooth is a high tooth, the third bias reference voltage (U ref_c ) is set according to the maximum value of the common tooth and the minimum value of the high tooth. When the special tooth is a low tooth, the third bias reference voltage (U ref_c ) is set according to the minimum value of ordinary teeth and the maximum value of dwarf teeth.

6. A method for identifying a special tooth speed signal comprises: The transconductance amplifier circuit (1) receives the speed signal containing the special tooth signal and converts it into a current signal (I o ); The current signal (I o ) is converted into a voltage, and a single-ended voltage signal (U o ); Using the first bias reference voltage (U ref_b ) completes full-wave rectification and amplitude adjustment to generate the first signal (U f ) and the second signal (U c ); Using the third bias reference voltage (U ref_c ) completes the second signal (U c ) and output a pulse signal indicating the position of the special tooth signal.

7. The method according to claim 6, characterized in that Further comprising, using a second bias reference voltage (U ref_b+ ) for the first signal (U f ) is integrated and a DC signal (I b ) is used as the amplification factor of the transconductance discharge circuit and is used for negative feedback gain control of the transconductance amplifier circuit (1).

8. The method according to claim 6, characterized in that When the special tooth is a high tooth, the third bias reference voltage (U ref_c ) is set according to the maximum value of the common tooth and the minimum value of the high tooth. When the special tooth is a low tooth, the third bias reference voltage (U ref_c ) is set according to the minimum value of ordinary teeth and the maximum value of dwarf teeth.

9. The method according to claim 7, characterized in that The second bias reference voltage (U ref_b+ ) is the first bias reference voltage (U ref_b ) of 125%.

10. The method according to claim 6, characterized in that The first bias reference voltage (U ref_b ) is 2v, the second bias reference voltage (U ref_b+ ) is 2.5v, the third bias reference voltage (U ref_c ) is 2.85v.

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