CN105738807A - High-speed dynamic pressure gyro motor ground touch rotating speed test system - Google Patents
High-speed dynamic pressure gyro motor ground touch rotating speed test system Download PDFInfo
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Abstract
The present invention relates to a high-speed dynamic pressure gyro motor ground touch rotating speed test system, and relates to the motor test field. The high-speed dynamic pressure gyro motor ground touch rotating speed test system comprises a motor control unit, a sensor unit, a high-speed data acquisition unit, a central processing unit, a voltage comparison unit, a signal conditioning unit, a communication unit, an upper computer data analyzing and resolving unit, a test result displaying and storing unit, etc., can measure the ground touch rotating speed of a motor and detect the characteristic of a dynamic pressure gas bearing accurately, and can further obtain the state characteristic indexes of a dynamic pressure bearing. The system of the present invention adopts a counter electromotive force measurement method, can measure the characteristic parameters of the motor under the states, such as a floater, a gyro instrument, an inertial platform, etc., and enables the problem that after being assembled, the gyro motor only can measure the current and the voltage, but can not measure other characteristic parameters to be solved effectively. The measurement system can evaluate the operation state of the gyro motor real-timely, and has very important actual engineering significance for enhancing the reliability of a gyro instrument product and improving the quality and precision of a dynamic pressure motor product.
Description
Technical Field
The invention relates to the field of motor testing, in particular to a touchdown rotating speed testing system of a high-speed dynamic pressure gyro motor.
Background
The dynamic pressure gyro motor is a high-speed running motor using dynamic pressure air bearing as supporting structure, and is applied to gyroscope and inertial platform because of its long service life, ultra-low vibration, low noise, strong overload resistance and small rotation speed fluctuation. At present, the method for measuring the characteristic parameters of the dynamic pressure gyro motor is to measure the mechanical characteristics of the dynamic pressure gyro motor by matching a power meter with a reaction torque tester in a motor state. However, when the dynamic pressure motor is installed in a gyro instrument or on an inertia platform, the quality of the motor body and the dynamic pressure bearing can be indirectly judged only by collecting the voltage and the current of the gyro motor, and the moment parameter of the air bearing, which is the most critical of the motor, cannot be measured, so that the gyro motor does not form direct quantitative evaluation on the air bearing from the installation of the gyro instrument and the platform to the final springing use.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, provides a touchdown rotating speed testing system of a high-speed dynamic-pressure gyro motor, is used for testing the high-speed permanent magnet and hysteresis dynamic-pressure motor, and solves the problem that the gyro motor cannot quantitatively evaluate the state of an air bearing after being installed in an instrument and a platform and finally bounced.
The above purpose of the invention is realized by the following technical scheme:
a touchdown rotating speed testing system of a high-speed dynamic pressure gyro motor comprises a motor control unit, a voltage sensor unit, a three-phase voltage acquisition unit, a voltage comparison unit, a signal conditioning unit, a filtering unit, a high-speed data acquisition unit, a central processing unit, a communication unit, an upper computer data analysis and calculation unit and a test result display and storage unit;
a motor control unit: receiving a control signal transmitted by the central processing unit, and controlling the starting and stopping of an external gyro motor;
a voltage sensor unit: testing three-phase back electromotive force of an external gyro motor after power failure to generate a three-phase voltage signal, and transmitting the three-phase voltage signal to a three-phase voltage acquisition unit;
three-phase voltage acquisition unit: collecting three-phase voltage signals transmitted by a voltage sensor unit, and transmitting the three-phase voltage signals to a voltage comparison unit;
a voltage comparison unit: receiving a three-phase voltage signal transmitted by a three-phase voltage acquisition unit, and comparing the three-phase voltage signal with a standard voltage; when the voltage amplitude is larger than 12V, the three-phase voltage signals are output to the signal conditioning unit; when the voltage amplitude is 1.25V-12V, the three-phase voltage signals are output to the signal conditioning unit; when the voltage amplitude is 0-1.25V, the three-phase voltage signals are transmitted to the filtering unit;
a signal conditioning unit: receiving a three-phase voltage signal with a voltage amplitude larger than 12V transmitted by the voltage comparison unit, performing voltage reduction processing, adjusting the voltage to be within 1.25V-12V, performing square wave conversion to generate a three-phase standard square wave voltage signal, and transmitting the three-phase standard square wave voltage signal to the filtering unit; receiving three-phase voltage signals with the voltage amplitude of 1.25-12V transmitted by the voltage comparison unit, performing square wave conversion to generate three-phase standard square wave voltage signals, and transmitting the three-phase standard square wave voltage signals to the filtering unit; receiving the boosted three-phase voltage signals transmitted by the filtering unit, performing square wave conversion on the three-phase voltage signals to convert the three-phase voltage signals into three-phase standard square wave voltage signals, and transmitting the three-phase standard square wave voltage signals to the filtering unit;
a filtering unit: receiving the 0-1.25V three-phase voltage signal transmitted by the voltage comparison unit, adjusting the voltage signal to 1.25V-12V after filtering and boosting, and outputting the boosted three-phase voltage signal to the signal conditioning unit; receiving a three-phase standard square wave voltage signal transmitted by the signal conditioning unit, and directly outputting the three-phase standard square wave voltage signal to the high-speed data acquisition unit; or the three-phase standard square wave voltage signal is generated into a three-phase synchronous square wave voltage signal and then transmitted to the high-speed data acquisition unit;
a high-speed data acquisition unit: receiving a three-phase standard square wave voltage signal or a three-phase synchronous square wave voltage signal transmitted by a filtering unit; counting for 1 time when the square wave voltage signal meets a zero crossing point, calculating a counting result j to be 1, 2, 3 … … q, wherein q is a positive integer, and transmitting the counting result to a central processing unit;
a central processing unit: firstly, sending a gyro motor starting signal to a motor control unit, and after the motor control unit controls an external gyro motor to reach a synchronous rotating speed, sending a power-off control signal by a central processing unit and transmitting the power-off control signal to the motor control unit; synchronously receiving the counting result transmitted by the high-speed data acquisition unit, storing the counting result, and calculating a back electromotive force half period Tj; tj is the counting result multiplied by the inherent trigger time of the crystal oscillator of the counter, and the counting result and the back electromotive force half period Tj are transmitted to an upper computer data analysis and calculation unit through a communication unit;
a communication unit: receiving the counting result and the back electromotive force half period T transmitted from the central processing unitjAnd the counting result and the back electromotive force half period T are comparedjThe data are transmitted to an upper computer data analysis and calculation unit;
the upper computer data analysis and calculation unit: receiving the counting result and the back electromotive force half period T transmitted by the communication unitj(ii) a Calculating to obtain inertial running time, touchdown rotating speed and touchdown resisting moment parameters; the inertial running time, the touchdown rotating speed and the touchdown resisting moment are transmitted to a test result display and storage unit;
the test result display and storage unit: receiving inertial running time, touchdown rotating speed and touchdown resisting moment transmitted by an upper computer data resolving analysis unit; displaying and storing real-time numerical values of the rotating speed in the testing process; and the parameters of the touchdown resistance moment, the touchdown time, the touchdown rotating speed and the touchdown resistance moment are displayed on a test result interface after the test is finished.
In the above system for testing the touchdown rotation speed of the high-speed dynamic pressure gyro motor, in the filtering unit, when the amplitude of the three-phase standard square wave voltage signal is not within the set filtering voltage range, the filtering unit directly outputs the three-phase standard square wave voltage signal to the high-speed data acquisition unit; when the amplitude of the three-phase standard square wave voltage signal is within the filtering voltage range, the filtering unit carries out filtering and differential amplification processing on the three-phase standard square wave voltage signal, noise filtering is carried out on the three-phase standard square wave voltage signal with the voltage amplitude within the preset voltage range, the voltage amplitude is amplified by 10 times, the frequency is kept synchronous, a three-phase synchronous square wave voltage signal is generated, and the three-phase synchronous square wave voltage signal is transmitted to the high-speed data acquisition unit.
In the touchdown rotating speed testing system of the high-speed dynamic pressure gyro motor, the set filter voltage range is-1- +1 v; the preset voltage range is as follows: -1.25V- + 1.25V.
In the above mentioned system for testing touchdown speed of the high speed dynamic pressure gyro motor, the method for calculating the parameters of inertial running time, touchdown speed and touchdown resistance moment is as follows:
coasting time T:
wherein,Tjcounter electromotive force half period T for the process from motor power-off to rotor stallingjThe unit is s; q is all half cycles of the three-phase counter potential signal in the process from the power-off of the motor to the stop of the rotor, namely a counting result;
change value delta T of adjacent half period in power-off inertia running processjComprises the following steps:
ΔTj=Tj-Tj-1j is 1, 2, 3 … … q, unit s;
time to ground Tc: the time from the power failure of the external gyro motor to the touchdown of the external gyro motor, wherein c is the half-cycle number of voltage at the touchdown moment, c is a positive integer, and the gyro motor is determined to be touchdown when q is equal to c;
and (3) judging the grounding rotating speed: the value of change Δ T of adjacent half-cyclescIf the value is larger than the experience set value, the value of c can be solved;
ΔTc=|Tc-Tc-1|>the unit s;
real-time rotation speed n:
n=60/p(Tj+Tj-1) Unit rpm;
ground contact rotating speed nc:
nc=60/p(Tc+Tc-1) Unit rpm;
rotational speed fluctuation △ omegaj:
ωj=π/Tj;Δωj=π/Tj-π/Tj-1
Wherein p is the number of pole pairs of the motor;
ωjthe unit is rad/s for the rotation angular velocity of the motor;
△ωjis the rotation angular velocity variation with unit of rad/s;
rotational resistance moment M: the total resisting moment borne by the external gyro motor in the process of stopping after power failure;
ground contact resistance moment Mc: is TcRotational moment of resistance at touchdown time;
wherein J is the rotational inertia of the external gyro motor rotor, △ omegacThe unit of the variation of the rotation angular speed of the gyro motor at the touchdown time is rad/s.
In the above mentioned high speed dynamic pressure gyro motor grounding rotating speed test system, in the signal conditioning unit, a programmable gain instrument amplifier and a fully differential funnel attenuation amplifier are cascaded to provide high differential input impedance and-110 dB total harmonic distortion, the amplitude of the counter electromotive force signal is adjusted to be in the tested effective range of-12 to +12V, and simultaneously the counter electromotive force three-phase sine wave signal is converted into a square wave signal.
In the above mentioned system for testing the touchdown rotation speed of the high-speed dynamic pressure gyro motor, the filtering unit is an anti-aliasing filter.
Compared with the prior art, the invention has the following advantages:
(1) the invention adopts a counter electromotive force measuring method to extract an effective half period signal T from a three-phase counter electromotive force signaljThe method realizes the measurement of characteristic parameters of the external gyro motor including touchdown resistance moment, touchdown time, touchdown rotating speed, inertial running time and the like in the states of a floater, a gyro instrument, an inertial platform and the like, and effectively solves the problem that the gyro motor does not form a direct quantitative evaluation method for the air bearing from the time of being installed in the instrument and the platform to the time of final springing;
(2) the invention adopts an upper computer data analysis and calculation unit and adopts a formula The inertial running time of the gyro motor in different states is measured; by the formula Δ Tc=|Tc-Tc-1|>When the value of change of adjacent half-cycles is Δ TcWhen the contact rotation speed is larger than the experience set value, the contact rotation speed of the gyro motor in different states is measured; by the formula n 60/p (T)j+Tj-1) Realize gyro electricityMeasuring the real-time rotating speed of the machine in different states; by the formulaThe measuring curve of the spinning resistance moment M of the gyro motor in the process of stalling after power failure is realized;
(3) according to the invention, the filtering unit adopts an anti-aliasing filter to limit the bandwidth of the signal and the noise provided for the input end of the ADC, so that the unnecessary aliasing effect is prevented, and the signal-to-noise ratio of the back electromotive force signal at the later stage of the inertial rotation of the gyro motor is improved;
(4) the signal conditioning unit of the invention cascades the programmable gain instrument amplifier and the fully differential funnel attenuation amplifier to provide high differential input impedance and-110 dB total harmonic distortion.
Drawings
FIG. 1 is a schematic block diagram of a touchdown rotation speed testing system of a high-speed dynamic pressure gyro motor according to the present invention;
fig. 2 is a schematic diagram of the back-emf waveform conversion method of the present invention.
Detailed Description
The invention is described in further detail below with reference to the following figures and specific examples:
as shown in fig. 1, the schematic block diagram of a touchdown and rotation speed testing system of a high-speed dynamic-pressure gyro motor is shown, and the schematic block diagram of the touchdown and rotation speed testing system comprises a motor control unit, a voltage sensor unit, a three-phase voltage acquisition unit, a voltage comparison unit, a signal conditioning unit, a filtering unit, a high-speed data acquisition unit, a central processing unit, a communication unit, an upper computer data analysis and calculation unit and a test result display and storage unit;
a motor control unit: receiving a control signal transmitted by the central processing unit, and controlling the starting and stopping of an external gyro motor;
a voltage sensor unit: testing three-phase back electromotive force of an external gyro motor after power failure to generate a three-phase voltage signal, and transmitting the three-phase voltage signal to a three-phase voltage acquisition unit;
three-phase voltage acquisition unit: collecting three-phase voltage signals transmitted by a voltage sensor unit, and transmitting the three-phase voltage signals to a voltage comparison unit;
a voltage comparison unit: receiving a three-phase voltage signal transmitted by a three-phase voltage acquisition unit, and comparing the three-phase voltage signal with a standard voltage; when the voltage amplitude is larger than 12V, the three-phase voltage signals are output to the signal conditioning unit; when the voltage amplitude is 1.25V-12V, the three-phase voltage signals are output to the signal conditioning unit; when the voltage amplitude is 0-1.25V, the three-phase voltage signals are transmitted to the filtering unit;
a signal conditioning unit: the programmable gain instrument amplifier is cascaded with a fully differential funnel attenuation amplifier to provide high differential input impedance and-110 dB total harmonic distortion, the amplitude of a back electromotive force signal is adjusted to be in a tested effective range of-12 to +12V, and simultaneously a back electromotive force three-phase sine wave signal is converted into a square wave signal; receiving a three-phase voltage signal with a voltage amplitude larger than 12V transmitted by the voltage comparison unit, performing voltage reduction processing, adjusting the voltage to be within 1.25V-12V, performing square wave conversion to generate a three-phase standard square wave voltage signal, and transmitting the three-phase standard square wave voltage signal to the filtering unit; receiving three-phase voltage signals with the voltage amplitude of 1.25-12V transmitted by the voltage comparison unit, performing square wave conversion to generate three-phase standard square wave voltage signals, and transmitting the three-phase standard square wave voltage signals to the filtering unit; receiving the boosted three-phase voltage signals transmitted by the filtering unit, performing square wave conversion on the three-phase voltage signals to convert the three-phase voltage signals into three-phase standard square wave voltage signals, and transmitting the three-phase standard square wave voltage signals to the filtering unit;
a filtering unit: is an anti-aliasing filter; receiving the 0-1.25V three-phase voltage signal transmitted by the voltage comparison unit, adjusting the voltage signal to 1.25V-12V after filtering and boosting, and outputting the boosted three-phase voltage signal to the signal conditioning unit; receiving a three-phase standard square wave voltage signal transmitted by the signal conditioning unit, and directly outputting the three-phase standard square wave voltage signal to the high-speed data acquisition unit; or the three-phase standard square wave voltage signal is generated into a three-phase synchronous square wave voltage signal and then transmitted to the high-speed data acquisition unit;
when the amplitude of the three-phase standard square wave voltage signal is not in the set filtering voltage range, the filtering unit directly outputs the three-phase standard square wave voltage signal to the high-speed data acquisition unit; when the amplitude of the three-phase standard square wave voltage signal is within the filtering voltage range, the filtering unit carries out filtering and differential amplification processing on the three-phase standard square wave voltage signal, noise filtering is carried out on the three-phase standard square wave voltage signal with the voltage amplitude within the preset voltage range, the voltage amplitude is amplified by 10 times, the frequency is kept synchronous, a three-phase synchronous square wave voltage signal is generated, and the three-phase synchronous square wave voltage signal is transmitted to the high-speed data acquisition unit;
wherein the set filter voltage range is-1- +1 v; the preset voltage range is as follows: -1.25V- + 1.25V.
A high-speed data acquisition unit: receiving a three-phase standard square wave voltage signal or a three-phase synchronous square wave voltage signal transmitted by a filtering unit; counting for 1 time when the square wave voltage signal meets a zero crossing point, calculating a counting result j to be 1, 2, 3 … … q, wherein q is a positive integer, and transmitting the counting result to a central processing unit;
a central processing unit: firstly, sending a gyro motor starting signal to a motor control unit, and after the motor control unit controls an external gyro motor to reach a synchronous rotating speed, sending a power-off control signal by a central processing unit and transmitting the power-off control signal to the motor control unit; synchronously receiving the counting result transmitted by the high-speed data acquisition unit, storing the counting result, and calculating a back electromotive force half period Tj; tj is the counting result multiplied by the inherent trigger time of the crystal oscillator of the counter, and the counting result and the back electromotive force half period Tj are transmitted to an upper computer data analysis and calculation unit through a communication unit;
a communication unit: receive the signal from the CPUThe counting result and the back electromotive force half period TjAnd the counting result and the back electromotive force half period T are comparedjThe data are transmitted to an upper computer data analysis and calculation unit;
the upper computer data analysis and calculation unit: receiving the counting result and the back electromotive force half period T transmitted by the communication unitj(ii) a Calculating to obtain inertial running time, touchdown rotating speed and touchdown resisting moment parameters; the inertial running time, the touchdown rotating speed and the touchdown resisting moment are transmitted to a test result display and storage unit;
the test result display and storage unit: receiving inertial running time, touchdown rotating speed and touchdown resisting moment transmitted by an upper computer data resolving analysis unit; displaying and storing real-time numerical values of the rotating speed in the testing process; and the parameters of the touchdown resistance moment, the touchdown time, the touchdown rotating speed and the touchdown resistance moment are displayed on a test result interface after the test is finished.
The gyro motor control method comprises the steps that firstly, a central processing unit sends a gyro motor starting signal and transmits a control signal to a motor control unit, a motor driving part of the motor control unit controls a motor to start, when a gyro motor reaches synchronous rotation speed, the central processing unit sends a power-off control signal and transmits the control signal to the motor control unit, a high-speed counter is triggered to start counting synchronously, the motor control unit receives the power-off control signal transmitted by the central processing unit, outputs the control signal to the motor driving part and controls the start, power-off and stop of the gyro motor; the voltage sensor unit is used for testing three-phase back electromotive force of the gyro motor after power failure, generating three-phase sinusoidal voltage signals and transmitting the three-phase sinusoidal voltage signals to the three-phase voltage acquisition unit of the lower computer; the three-phase voltage acquisition unit transmits the acquired three-phase sinusoidal voltage signals to the voltage comparison unit; the voltage comparison unit compares the three-phase sinusoidal voltage signal with a standard voltage, judges whether the voltage is within the voltage signal range of the high-speed data acquisition unit, and transmits the comparison result to the signal conditioning unit; if the three-phase sinusoidal voltage signal collected by the signal conditioning unit is in the voltage signal range of the high-speed data acquisition unit, no processing is carried out, and if the three-phase sinusoidal voltage signal is not in the voltage signal range of the high-speed data acquisition unitThen, carrying out pressure reduction treatment; the three-phase sinusoidal voltage signals in the voltage signal range are subjected to square wave conversion and converted into three-phase standard square wave voltage signals, and the processed three-phase square wave voltage signals are transmitted to a filtering unit; when the amplitude of the three-phase standard square wave voltage signal received by the filtering unit is not within the filtering voltage range, the signal is directly transmitted to the high-speed data acquisition unit; when the amplitude of the square wave voltage signal is within the effective filtering voltage range, filtering and differential amplification processing are carried out, three-phase standard square wave voltage signals with the voltage amplitude within (-1.25V, +1.25V) are subjected to noise filtering, the voltage amplitude is amplified by 10 times, the frequency is kept synchronous, three-phase synchronous square wave voltage signals are generated, and the three-phase synchronous square wave voltage signals are transmitted to a high-speed data acquisition unit; the high-speed data acquisition unit receives the three-phase standard square wave voltage signal and the three-phase synchronous square wave voltage signal transmitted by the filtering unit, square wave counting signals generated by the high-precision counter respectively enter a counting enabling end and a high-speed analog quantity acquisition end in the high-speed data acquisition unit, and counting results and zero-crossing signals are transmitted to the central processing unit; the central processing unit receives the counting signal and the zero-crossing collecting signal transmitted from the high-speed data collecting unit, stores and counter electromotive force half period time TjCalculating, j ═ 1, 2, 3 … … q; t isjMultiplying the value of the square wave counting signal between every two zero-crossing signals by the inherent trigger time of the crystal oscillator of the counter, and adding the square wave counting signal and the time period TjThe value is transmitted to the upper computer processing part through the communication unit; the upper computer data analysis resolving unit receives the back electromotive force half period time T transmitted by the communication unitjAnd the required motor characteristic parameters can be obtained through the following calculation principle: including touchdown resistance moment, touchdown time, touchdown speed, inertial running time, etc.
The inertial running time, the touchdown rotating speed and the touchdown resisting moment parameters are calculated as follows:
coasting time T:
wherein, TjCounter electromotive force half period T for the process from motor power-off to rotor stallingjThe unit is s; q is all half cycles of the three-phase counter potential signal in the process from the power-off of the motor to the stop of the rotor, namely a counting result;
change value delta T of adjacent half period in power-off inertia running processjComprises the following steps:
ΔTj=Tj-Tj-1j is 1, 2, 3 … … q, unit s;
time to ground Tc: the time from the power failure of the external gyro motor to the touchdown of the external gyro motor, wherein c is the half-cycle number of voltage at the touchdown moment, c is a positive integer, and the gyro motor is determined to be touchdown when q is equal to c;
and (3) judging the grounding rotating speed: the value of change Δ T of adjacent half-cyclescIf the value is larger than the experience set value, the value of c can be solved;
ΔTc=|Tc-Tc-1|>the unit s;
real-time rotation speed n:
n=60/p(Tj+Tj-1) Unit rpm;
ground contact rotating speed nc:
nc=60/p(Tc+Tc-1) Unit rpm;
rotational speed fluctuation △ omegaj:
ωj=π/Tj;Δωj=π/Tj-π/Tj-1
Wherein p is the number of pole pairs of the motor;
ωjthe unit is rad/s for the rotation angular velocity of the motor;
△ωjis the rotation angular velocity variation with unit of rad/s;
rotational resistance moment M: the total resisting moment borne by the external gyro motor in the process of stopping after power failure;
ground contact resistance moment Mc: is TcRotational moment of resistance at touchdown time;
wherein J is the rotational inertia of the external gyro motor rotor, △ omegacThe unit of the variation of the rotation angular speed of the gyro motor at the moment of touchdown is rad/s;
as shown in fig. 2, which is a diagram of a principle of waveform conversion by a back electromotive force method, it can be known that a voltage sensor unit tests a three-phase back electromotive force of a gyro motor after power failure to generate a three-phase sinusoidal voltage signal, and the three-phase sinusoidal voltage signal is transmitted to a three-phase voltage acquisition unit of a lower computer; the three-phase voltage acquisition unit transmits the acquired three-phase sinusoidal voltage signals to the voltage comparison unit; the voltage comparison unit compares the three-phase sinusoidal voltage signal with the standard voltage, and because the span interval of the back electromotive force voltage of the tested motor is large and the rotating speed is high, the amplification and reduction times of the voltage are required to be adjusted according to different conditions so as to meet the requirement of AD measurement. The measurement and signal conditioning work of a circuit is realized by using a high-speed programmable instrument amplifier, attenuation and amplification are arranged in a signal path, differential output is needed to drive a high-performance analog-digital converter, a programmable gain instrument amplifier is cascaded with a fully differential funnel (attenuation) amplifier, the programmable gain instrument amplifier provides high differential input impedance and-110 dB total harmonic distortion, the comparison and adjustment of three-phase sinusoidal voltage signals can be realized, and the three-phase sinusoidal voltage signals are adjusted to be within the voltage signal range of a high-speed data acquisition unit. Meanwhile, the power-off moment of the three-phase sine voltage signal is judged by external power-off triggering and waveform conversion of internal positive and negative electromotive force, a high-speed external interrupt judgment processor and a high-speed AD (the speed is 28Msps) are needed, namely, the waveform in a 1kHz frequency can be continuously sampled 2333 times in one period, the conversion time and the waveform conversion slope can be very quickly judged, and the three-phase sine voltage signal is synchronously converted into a three-phase standard square wave signal.
The counting signal is generated by a high-speed data acquisition unit selecting a high-precision counter with the clock frequency of 200MHz, and the clock frequency can reach 330M by utilizing a frequency multiplier; by taking a 4-way 32-bit superposable accumulation counter, the maximum value of countable is 232, i.e. the minimum countable resolution time is 0.003 microseconds, which is enough to satisfy the resolution response error time of microsecond level. At the starting moment of the test, the central processing unit synchronously triggers the high-speed counter to start counting, receives the counting signal and the zero-crossing collecting signal transmitted by the high-speed data collecting unit, stores all the signals and calculates the back electromotive force half period Tj,j=1,2,3……q;TjMultiplying the value of the square wave counting signal between every two zero-crossing signals by the inherent trigger time of the counter crystal oscillator, and dividing the square wave counting signal and the counter electromotive force half period TjTransmitted to the upper computer processing part through the communication unit and processed by the formula delta Tc=|Tc-Tc-1|>When the value of change of adjacent half-cycles is Δ TcWhen the contact time of the gyro motor is larger than the experience set value, the judgment of the contact time of the gyro motor can be realized.
The working principle of the invention is as follows:
the leading-out wire of the dynamic pressure motor is reliably connected with the corresponding phase sequence of the motor power supply according to the phase sequence, and the tester is also connected to the leading-out wire of the motor according to the corresponding phase sequence. And controlling the motor to start, cutting off a power supply of the dynamic pressure motor after the dynamic pressure motor is stabilized to the synchronous rotating speed, and collecting the counter electromotive force data of the motor from the power-off moment until the motor stops rotating. The high-speed data acquisition unit acquires voltage signals of the back electromotive force element, transmits the voltage signals to the central processing unit for data processing, and calculates the processed data to the upper computer through the communication unit to obtain required parameters of the gyro motor, wherein the parameters comprise real-time rotating speed, ground contact resistance moment, inertial running time, ground contact time and ground contact rotating speed.
Compared with the prior art, the invention has the advantages that:
at present, the method for measuring the characteristic parameters of the dynamic pressure gyro motor is to measure the mechanical characteristics of the dynamic pressure gyro motor by matching a power meter with a reaction torque tester in a motor state. However, when the dynamic pressure motor is installed in a gyro instrument or on an inertia platform, the quality of the motor body and the dynamic pressure bearing can be indirectly judged only by collecting the voltage and the current of the gyro motor, and the moment parameter of the air bearing, which is the most critical of the motor, cannot be measured, so that the gyro motor does not form direct quantitative evaluation on the air bearing from the installation of the gyro instrument and the platform to the final springing use. By using the touchdown rotating speed testing system of the high-speed dynamic pressure gyro motor, only the outgoing line between the gyro motor and a power supply needs to be connected into the system, and characteristic parameters such as real-time rotating speed, touchdown resistance moment, inertial running time, touchdown rotating speed and the like can be obtained by measuring and calculating three opposite potential signals of the gyro motor, so that the states of the dynamic pressure motor and the air bearing can be judged, and reliable reference is provided for instruments and an inertial platform.
Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.
Claims (6)
1. The utility model provides a high-speed dynamic pressure top motor contacts to earth rotational speed test system which characterized in that: the device comprises a motor control unit, a voltage sensor unit, a three-phase voltage acquisition unit, a voltage comparison unit, a signal conditioning unit, a filtering unit, a high-speed data acquisition unit, a central processing unit, a communication unit, an upper computer data analysis and calculation unit and a test result display and storage unit;
a motor control unit: receiving a control signal transmitted by the central processing unit, and controlling the starting and stopping of an external gyro motor;
a voltage sensor unit: testing three-phase back electromotive force of an external gyro motor after power failure to generate a three-phase voltage signal, and transmitting the three-phase voltage signal to a three-phase voltage acquisition unit;
three-phase voltage acquisition unit: collecting three-phase voltage signals transmitted by a voltage sensor unit, and transmitting the three-phase voltage signals to a voltage comparison unit;
a voltage comparison unit: receiving a three-phase voltage signal transmitted by a three-phase voltage acquisition unit, and comparing the three-phase voltage signal with a standard voltage; when the voltage amplitude is larger than 12V, the three-phase voltage signals are output to the signal conditioning unit; when the voltage amplitude is 1.25V-12V, the three-phase voltage signals are output to the signal conditioning unit; when the voltage amplitude is 0-1.25V, the three-phase voltage signals are transmitted to the filtering unit;
a signal conditioning unit: receiving a three-phase voltage signal with a voltage amplitude larger than 12V transmitted by the voltage comparison unit, performing voltage reduction processing, adjusting the voltage to be within 1.25V-12V, performing square wave conversion to generate a three-phase standard square wave voltage signal, and transmitting the three-phase standard square wave voltage signal to the filtering unit; receiving three-phase voltage signals with the voltage amplitude of 1.25-12V transmitted by the voltage comparison unit, performing square wave conversion to generate three-phase standard square wave voltage signals, and transmitting the three-phase standard square wave voltage signals to the filtering unit; receiving the boosted three-phase voltage signals transmitted by the filtering unit, performing square wave conversion on the three-phase voltage signals to convert the three-phase voltage signals into three-phase standard square wave voltage signals, and transmitting the three-phase standard square wave voltage signals to the filtering unit;
a filtering unit: receiving the 0-1.25V three-phase voltage signal transmitted by the voltage comparison unit, adjusting the voltage signal to 1.25V-12V after filtering and boosting, and outputting the boosted three-phase voltage signal to the signal conditioning unit; receiving a three-phase standard square wave voltage signal transmitted by the signal conditioning unit, and directly outputting the three-phase standard square wave voltage signal to the high-speed data acquisition unit; or the three-phase standard square wave voltage signal is generated into a three-phase synchronous square wave voltage signal and then transmitted to the high-speed data acquisition unit;
a high-speed data acquisition unit: receiving a three-phase standard square wave voltage signal or a three-phase synchronous square wave voltage signal transmitted by a filtering unit; counting for 1 time when the square wave voltage signal meets a zero crossing point, calculating a counting result j to be 1, 2, 3 … … q, wherein q is a positive integer, and transmitting the counting result to a central processing unit;
a central processing unit: firstly, sending a gyro motor starting signal to a motor control unit, and after the motor control unit controls an external gyro motor to reach a synchronous rotating speed, sending a power-off control signal by a central processing unit and transmitting the power-off control signal to the motor control unit; synchronously receiving the counting result transmitted by the high-speed data acquisition unit, storing the counting result, and calculating a back electromotive force half period Tj; tj is the counting result multiplied by the inherent trigger time of the crystal oscillator of the counter, and the counting result and the back electromotive force half period Tj are transmitted to an upper computer data analysis and calculation unit through a communication unit;
a communication unit: receiving the counting result and the back electromotive force half period T transmitted from the central processing unitjAnd the counting result and the back electromotive force half period T are comparedjThe data are transmitted to an upper computer data analysis and calculation unit;
the upper computer data analysis and calculation unit: receiving the counting result and the back electromotive force half period T transmitted by the communication unitj(ii) a Calculating to obtain inertial running time, touchdown rotating speed and touchdown resisting moment parameters; the inertial running time, the touchdown rotating speed and the touchdown resisting moment are transmitted to a test result display and storage unit;
the test result display and storage unit: receiving inertial running time, touchdown rotating speed and touchdown resisting moment transmitted by an upper computer data resolving analysis unit; displaying and storing real-time numerical values of the rotating speed in the testing process; and the parameters of the touchdown resistance moment, the touchdown time, the touchdown rotating speed and the touchdown resistance moment are displayed on a test result interface after the test is finished.
2. The touchdown rotation speed testing system of the high-speed dynamic pressure gyro motor as claimed in claim 1, wherein: in the filtering unit, when the amplitude of the three-phase standard square wave voltage signal is not in the set filtering voltage range, the filtering unit directly outputs the three-phase standard square wave voltage signal to the high-speed data acquisition unit; when the amplitude of the three-phase standard square wave voltage signal is within the filtering voltage range, the filtering unit carries out filtering and differential amplification processing on the three-phase standard square wave voltage signal, noise filtering is carried out on the three-phase standard square wave voltage signal with the voltage amplitude within the preset voltage range, the voltage amplitude is amplified by 10 times, the frequency is kept synchronous, a three-phase synchronous square wave voltage signal is generated, and the three-phase synchronous square wave voltage signal is transmitted to the high-speed data acquisition unit.
3. The touchdown rotation speed testing system of the high-speed dynamic pressure gyro motor as claimed in claim 2, wherein: the set filter voltage range is-1- +1 v; the preset voltage range is as follows: -1.25V- + 1.25V.
4. The touchdown rotation speed testing system of the high-speed dynamic pressure gyro motor as claimed in claim 1, wherein: the inertial running time, the touchdown rotating speed and the touchdown resisting moment parameters are calculated as follows:
coasting time T:
wherein, TjCounter electromotive force half period T for the process from motor power-off to rotor stallingjThe unit is s; q is all half cycles of the three-phase counter potential signal in the process from the power-off of the motor to the stop of the rotor, namely a counting result;
change value delta T of adjacent half period in power-off inertia running processjComprises the following steps:
ΔTj=Tj-Tj-1j is 1, 2, 3 … … q, unit s;
time to ground Tc: from outsideThe time from the power failure of the top motor to the touchdown of the external top motor, wherein c is the half-cycle number of voltage at the touchdown moment, c is a positive integer, and when q is equal to c, the top motor is determined to be touchdown;
and (3) judging the grounding rotating speed: the value of change Δ T of adjacent half-cyclescIf the value is larger than the experience set value, the value of c can be solved;
ΔTc=|Tc-Tc-1|>the unit s;
real-time rotation speed n:
n=60/p(Tj+Tj-1) Unit rpm;
ground contact rotating speed nc:
nc=60/p(Tc+Tc-1) Unit rpm;
rotational speed fluctuation △ omegaj:
ωj=π/Tj;Δωj=π/Tj-π/Tj-1
Wherein p is the number of pole pairs of the motor;
ωjthe unit is rad/s for the rotation angular velocity of the motor;
△ωjis the rotation angular velocity variation with unit of rad/s;
rotational resistance moment M: the total resisting moment borne by the external gyro motor in the process of stopping after power failure;
ground contact resistance moment Mc: is TcRotational moment of resistance at touchdown time;
wherein J is the rotational inertia of the external gyro motor rotor, △ omegacThe unit of the variation of the rotation angular speed of the gyro motor at the touchdown time is rad/s.
5. The touchdown rotation speed testing system of the high-speed dynamic pressure gyro motor as claimed in claim 1, wherein: in the signal conditioning unit, a programmable gain instrument amplifier and a fully differential funnel attenuation amplifier are cascaded to provide high differential input impedance and-110 dB total harmonic distortion, the amplitude of a back electromotive force signal is adjusted to be in a tested effective range of-12 to +12V, and meanwhile, a back electromotive force three-phase sine wave signal is converted into a square wave signal.
6. The touchdown rotation speed testing system of the high-speed dynamic pressure gyro motor as claimed in claim 1, wherein: the filtering unit is an anti-aliasing filter.
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Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107193235A (en) * | 2017-06-26 | 2017-09-22 | 中国核动力研究设计院 | A kind of processing method for core cascade screen revolution speed signal |
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Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231587C2 (en) * | 1981-08-26 | 1986-02-20 | Hitachi, Ltd., Tokio/Tokyo | Method and arrangement for detecting the friction location and the friction characteristics in a rotary machine |
US6591200B1 (en) * | 1998-06-16 | 2003-07-08 | M.E.A. Motor Inspection Ltd. | Method and system for performance testing of rotating machines |
CN202854161U (en) * | 2012-10-15 | 2013-04-03 | 赵小丽 | Measurement apparatus for rotating speed of asynchronous motor |
CN103411764A (en) * | 2013-08-09 | 2013-11-27 | 北京航天控制仪器研究所 | Inner rotor type gyro motor testing device |
CN104198754A (en) * | 2014-09-11 | 2014-12-10 | 中国人民解放军海军航空工程学院青岛校区 | Aero-engine rotation speed testing system |
CN104198935A (en) * | 2014-06-30 | 2014-12-10 | 北京航天控制仪器研究所 | Dynamic pressure motor parameter monitoring system and monitoring method |
CN204462180U (en) * | 2014-10-31 | 2015-07-08 | 北京兴华机械厂 | The measurement mechanism of gyro machine rotating speed under a kind of enclosed environment |
CN105116331A (en) * | 2015-09-08 | 2015-12-02 | 哈尔滨工业大学 | Test method for motor under high-temperature and high-pressure environment |
-
2016
- 2016-02-04 CN CN201610080920.8A patent/CN105738807B/en active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231587C2 (en) * | 1981-08-26 | 1986-02-20 | Hitachi, Ltd., Tokio/Tokyo | Method and arrangement for detecting the friction location and the friction characteristics in a rotary machine |
US6591200B1 (en) * | 1998-06-16 | 2003-07-08 | M.E.A. Motor Inspection Ltd. | Method and system for performance testing of rotating machines |
CN202854161U (en) * | 2012-10-15 | 2013-04-03 | 赵小丽 | Measurement apparatus for rotating speed of asynchronous motor |
CN103411764A (en) * | 2013-08-09 | 2013-11-27 | 北京航天控制仪器研究所 | Inner rotor type gyro motor testing device |
CN104198935A (en) * | 2014-06-30 | 2014-12-10 | 北京航天控制仪器研究所 | Dynamic pressure motor parameter monitoring system and monitoring method |
CN104198754A (en) * | 2014-09-11 | 2014-12-10 | 中国人民解放军海军航空工程学院青岛校区 | Aero-engine rotation speed testing system |
CN204462180U (en) * | 2014-10-31 | 2015-07-08 | 北京兴华机械厂 | The measurement mechanism of gyro machine rotating speed under a kind of enclosed environment |
CN105116331A (en) * | 2015-09-08 | 2015-12-02 | 哈尔滨工业大学 | Test method for motor under high-temperature and high-pressure environment |
Non-Patent Citations (1)
Title |
---|
李建春等: "气体动压轴承技术在陀螺电机中的应用", 《微电机》 * |
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CN110275107A (en) * | 2018-03-14 | 2019-09-24 | 上海鸣志电器股份有限公司 | A kind of test method of motor location torque |
CN110388303A (en) * | 2018-04-20 | 2019-10-29 | 新疆金风科技股份有限公司 | The measurement method of wind power generating set revolving speed, apparatus and system |
CN110388303B (en) * | 2018-04-20 | 2020-05-12 | 新疆金风科技股份有限公司 | Method, device and system for measuring rotating speed of wind generating set |
CN108768350A (en) * | 2018-05-23 | 2018-11-06 | 成都玖锦科技有限公司 | Upper lower edge can be separately adjustable stability square wave production method |
CN108768350B (en) * | 2018-05-23 | 2021-11-23 | 成都玖锦科技有限公司 | Method for generating stable square wave with independently adjustable upper edge and lower edge |
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CN108957322B (en) * | 2018-08-24 | 2021-08-20 | 佛山市顺德区金泰德胜电机有限公司 | Method for measuring back electromotive force of permanent magnet motor and measuring device used by method |
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