CN113514180B - Monitoring and screening control system and method for bearing surface friction torque of permanent magnet gyro motor - Google Patents

Abstract

The invention relates to a monitoring, screening and controlling system and method for the surface friction torque of a permanent magnet gyro motor bearing. The permanent magnetic gyroscope to be tested in the system is arranged on a test platform through a test tool; the variable voltage power supply outputs a direct current voltage signal with corresponding amplitude to the permanent magnet gyro controller according to the starting voltage instruction; the measurement and control computer sets the starting voltage amplitude, obtains a starting voltage command and sends the starting voltage command to the variable voltage power supply; loading preset variable-voltage starting acceleration rule parameters into a permanent magnet gyro controller, collecting motor rotating speed remote measuring digital quantity uploaded by the permanent magnet gyro controller, judging whether a gyro motor is started or not according to the digital quantity, and controlling the motor to stop rotating if the motor is started successfully; setting different starting voltage amplitudes to execute multiple times of motor starting, finding out a minimum starting voltage value, and calculating according to the minimum starting voltage value to obtain friction torque; and the permanent magnet gyro controller drives the tested permanent magnet gyro motor to start and stably rotate according to the variable voltage starting acceleration rule parameters.

Description

Monitoring and screening control system and method for bearing surface friction torque of permanent magnet gyro motor

technical field

The invention relates to a permanent magnet gyro motor bearing surface friction torque monitoring and screening control system and method, and belongs to the technical field of gyro reliability screening.

Background technique

The very high-precision three-floating gyroscope developed by the Institute of Aerospace Control Engineering is oriented to the needs of high-precision attitude measurement, focusing on in-depth research on gyro noise and random drift. For the first time, permanent magnet motors are used to replace traditional hysteresis motors, and the gyro accuracy is improved by an order of magnitude. The reliability and lifespan of a mechanical gyroscope mainly depends on the gyroscope motor, the rotating part. Motor bearing wear, small amount of oil on the bearing surface, and tiny excess in the bearing will lead to an increase in the static friction torque on the bearing surface. When the starting drive torque is exceeded, the motor will fail to start, resulting in the loss of the gyroscopic effect, resulting in serious consequences for the failure of the satellite mission. Therefore, during the development of gyroscopes, it is urgent to monitor the surface state of gyroscope motor bearings.

Due to the differences in the structure, process and control characteristics of the permanent magnet gyro motor and the hysteresis gyro motor, the original detection method of the bearing surface state of the hysteresis gyro motor is not suitable for the new permanent magnet gyro motor. At present, the detection method of the permanent magnet gyro motor bearing state is the sliding curve inflection point analysis method. The slide curve is shown in Figure 1: the abscissa in the figure is the slide time unit s, the ordinate is the speed unit r/min, and the inflection point is the critical point where the dynamic pressure air bearing motor changes from the air bearing state to the contact state with the bearing. The higher the speed value of the inflection point, the deterioration of the state of the bearing surface has occurred, resulting in a significantly shorter coasting time of the motor.

There are two deficiencies in the sliding curve inflection point analysis method:

1. The inflection point information includes the surface state of the gyro and the axial air gap information of the gyro bearing. There are differences in the axial air gap of each bearing. The smaller the air gap, the higher the inflection point of the coasting time. Therefore, the inflection point method is not applicable to measure the surface state of different gyro motor bearings. Difference comparison, this method is only suitable for analyzing the difference in bearing surface state during multiple test slides;

2. This method is a qualitative analysis, that is, it can only analyze when the inflection point is high, and the friction torque of the product becomes larger, but there is no quantitative measurement of the level of the friction torque itself, that is, there is no accurate quantitative analysis.

Contents of the invention

The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, and to propose a permanent magnet gyro motor bearing surface friction torque monitoring and screening control system and method, which can quantitatively obtain the bearing surface friction force of the permanent magnet gyro motor for aerospace under various postures distributed.

The technical solution of the present invention is: a monitoring and screening control system for the surface friction torque of the permanent magnet gyro motor bearing. , Measurement and control computer; the tested permanent magnet gyroscope is installed on the test platform through the test tooling;

The variable voltage power supply outputs a DC voltage signal of a corresponding magnitude to the permanent magnet gyro controller according to the starting voltage command;

The measurement and control computer sets the starting voltage range, and sends the starting voltage command to the variable voltage power supply; loads the preset variable voltage starting acceleration law parameters into the permanent magnet gyro controller, and collects the telemetry digital value of the motor speed uploaded by the permanent magnet gyro controller , through this digital quantity, judge whether the gyro motor is started, if the motor starts successfully, control the motor to stop; set different starting voltage ranges to perform multiple motor starts, find the minimum starting voltage value, and calculate the minimum current value according to the minimum starting voltage value , the friction torque is calculated according to the minimum current value;

The permanent magnet gyro controller converts the DC voltage signal output by the variable voltage power supply into three-phase alternating current according to the parameters of the variable voltage start-up acceleration law, and drives the measured permanent magnet gyro motor to start and rotate stably.

If the same starting voltage value is successful for N times of starting, it means that the current voltage value is greater than or equal to the minimum starting voltage value, lower the starting voltage value of the output of the transformer power supply, and start the motor repeatedly; , it means that the current voltage value is less than or equal to the minimum starting voltage value, adjust the starting voltage value output by the transformer power supply, and start the motor repeatedly until the minimum starting voltage value is found, and the N is greater than or equal to 1.

The variable voltage startup acceleration rule parameters include acceleration time, step time of step acceleration, and motor acceleration frequency value for each step time.

The permanent magnet gyro controller includes a start control module, a three-phase inverter, a back EMF detection module, a commutation logic module and a motor speed stabilization control module;

The start control module converts the variable voltage start acceleration law parameters input by the measurement and control computer into a start control square wave signal for six-way motor commutation, and outputs it to the three-phase inverter until the acceleration time expires;

The three-phase inverter module inverts the DC voltage signal output by the variable voltage power supply into three-phase alternating current, and outputs the three-phase alternating current to the measured permanent magnet gyro motor;

The back EMF zero-crossing detection module collects the terminal voltage signal of the measured permanent magnet gyro motor winding, performs zero-crossing detection, and obtains the back EMF zero-crossing square wave signal related to the motor speed. After the acceleration time expires, the back EMF zero-crossing The square wave signal is output to the commutation logic module;

The commutation logic module commutates the back EMF zero-crossing square wave signal to obtain six motor control square wave signals. The control square wave signal is divided into two channels, one output to the motor speed stabilization control module, and the other output to the three-phase inverter Transformer;

The motor speed stabilization control module analyzes the motor control square wave signal output by the commutation logic module, and obtains the motor speed remote measurement digital value and outputs it to the measurement and control computer.

The duty ratio of the back EMF zero crossing square wave signal is 1/2, and the commutation logic module converts the back EMF zero crossing square wave signal into six motor control square wave signals with a duty ratio of one third.

The formula for calculating the minimum starting current value is:

U _min = Ri _min

Among them, U _min is the minimum starting voltage value, R is the phase resistance of the three-phase winding of the motor, and i _min is the minimum starting current value.

The formula for calculating the friction torque is:

M _m =K _T i _min

Among them, M _m is the friction torque, K _T is the torque constant of the motor, and i is the minimum starting current value.

The test platform is placed on a vibration-isolated foundation.

Another technical solution of the present invention is: a method for monitoring, screening and controlling the surface friction torque of a permanent magnet gyro motor bearing, the method comprising the following steps:

St1, install the tested permanent magnet gyroscope on the test platform through the test tooling,

St2. Load the preset variable voltage start acceleration law parameters into the permanent magnet gyro controller. The variable voltage start acceleration law parameters include acceleration time, step time of step acceleration, and motor acceleration frequency value of each step time ;

St3, set the initial start-up voltage of the transformer power supply output;

St4. Start the gyro motor according to the set voltage and acceleration rules. If the motor starts successfully, control the motor to stop;

St5, repeat step St4 N times, if N times of starting are successful, it means that the current voltage value is greater than or equal to the minimum starting voltage value, lower the starting voltage value of the output of the transformer power supply, repeat steps St4 ~ step St5, once there is a failure to start, It means that the current voltage value is less than or equal to the minimum starting voltage value, and the starting voltage value output by the transformer power supply is adjusted up, and steps St4 to Step St5 are repeated until the minimum starting voltage value is found; said N is greater than or equal to 1;

St6. Calculate the minimum current value according to the minimum starting voltage value;

St7. Calculate the friction torque according to the minimum current value.

The formula for calculating the minimum starting current value is:

U _min = Ri _min

Among them, U _min is the minimum starting voltage value, R is the phase resistance of the three-phase winding of the motor, and i _min is the minimum starting current value.

The formula for calculating the friction torque is:

M _m =K _T i _min

Among them, M _m is the friction torque, K _T is the torque constant of the motor, and i is the minimum starting current value.

The beneficial effect of the present invention compared with prior art is:

(1), the present invention monitors the gyro friction torque by adjusting the starting voltage to find the minimum starting current method, compared with the traditional method of sliding time inflection point analysis friction torque, from qualitative analysis to quantitative analysis, improving the accuracy of gyro detection and screening, validity;

(2), the present invention adopts the control method of variable voltage gyro motor start-up acceleration law, compares traditional constant acceleration law start-up method, has guaranteed the reliability of gyro motor start-up;

(3) The starting acceleration law of the variable voltage gyro motor of the present invention is obtained from the acceleration curve of the constant voltage starting motor, and the precision is high.

(4) The present invention can effectively screen redundant faults, surface pollution faults, and wear faults to meet the high reliability requirements of model tasks.

Description of drawings

Fig. 1 is the sliding curve of a gyro motor at different times;

Fig. 2 is the flow chart of monitoring and screening control method for surface friction torque of permanent magnet gyro motor bearing in an embodiment of the present invention;

Fig. 3 is a block diagram of the monitoring and screening control system for the surface friction torque of the bearing surface of the permanent magnet gyro motor according to the embodiment of the present invention;

Fig. 4 is the equivalent circuit of the permanent magnet motor of the embodiment of the present invention;

Fig. 5 is the acceleration curve of the constant voltage starting motor of the embodiment of the present invention;

Fig. 6 (a) is the partially enlarged diagram of the acceleration curve of the motor in 0-5 seconds according to the embodiment of the present invention;

Fig. 6(b) is a partially enlarged view of the acceleration curve of the motor in 0-1 second according to the embodiment of the present invention.

Detailed ways

The present invention will be further elaborated below in conjunction with embodiment.

Combined with the structure, technology and control characteristics of permanent magnet gyro motors used in aerospace, a new minimum starting current analysis method is invented to quantify the surface friction torque of permanent magnet gyro motor bearings. In order to obtain the minimum current value of the product, an open-loop variable voltage gyro motor control method is adopted, and the minimum starting current is indirectly obtained through voltage adjustment, which realizes the engineering of the minimum starting current scheme. Since the permanent magnet gyro motor needs to be started with open-loop acceleration, unreasonable acceleration law will cause the gyro to lose step and stop. Therefore, the design scheme of the acceleration law for variable voltage startup is given.

(1), minimum starting current method design:

The relationship between the motor torque and the excitation current is:

T _e =K _T i (s1)

Among them, the torque constant (N·m/A) of the K _T motor is the same as the counter electromotive force constant, but the unit is different.

When the dynamic pressure air bearing is used in the gyro motor, the motion equation of the motor is:

为转子的机械角加速度(rad/s²)。由公式(s2)可知，电机转矩由转子动量矩、风阻、摩擦力矩组成，当电机启动瞬间，角速度很小，此时转子动量距、风阻可以忽略不计，此时电机转矩可以近似为摩擦力矩。即：In the formula, M _f ＝aω ² is the wind resistance (N m), M _m ＝bω is the friction torque (N m), a and b are the wind resistance torque coefficient and friction torque coefficient respectively, and J is the moment of inertia of the rotor (kg m m ² ),

is the mechanical angular acceleration of the rotor (rad/s ² ). It can be known from formula (s2) that the motor torque is composed of rotor momentum moment, wind resistance and friction torque. When the motor is started, the angular velocity is very small. At this time, the rotor momentum distance and wind resistance can be ignored. At this time, the motor torque can be approximated as friction moment. Right now:

T _e =M _m (s 3 )

It can be seen from the formula (s1) that the motor torque is proportional to the motor excitation current, and the comprehensive formulas (s1) and (s3) show that the excitation current is proportional to the friction torque. Right now:

M _m =K _T i (s4)

Therefore, the purpose of quantitatively monitoring the friction torque with the minimum starting current can be realized.

(2) Design of open-loop variable voltage gyro motor control method:

In order to realize the detection of the minimum starting current in engineering, it is necessary to design a set of starting control method, and the permanent magnet synchronous motor generally adopts the voltage control method.

The stator three-phase winding voltage balance equation of the permanent magnet gyro motor:

In the formula: u _a , u _b , u _c are the phase voltages of A, B, C three-phase windings respectively, and the unit is (V);

i _a , i _b , and i _c are the phase currents of the three-phase windings of A, B, and C respectively, and the unit is (A);

r _a , r _b , and r _c are the phase resistances of the three-phase windings of A, B, and C respectively, and the unit is (Ω);

e _a , e _b , e _c are the opposite potentials of the three-phase windings of A, B, and C respectively, and the unit is (V);

L _a , L _b , and L _c are the self-inductance of the three-phase windings of A, B, and C respectively, and the unit is (H);

L _ab , L _ac , L _bc , L _ba , L _ca , L _cb are the mutual inductances of phases AB, AC, BC, BA, CA, and CB respectively, and the unit is (H);

Differential operator

Since the three-phase windings are distributed symmetrically, there are:

Since the three-phase windings are star-connected, there are:

i _a +i _b +i _c =0

Therefore, the equation transforms into

The equivalent circuit of the three-phase stator winding can be obtained from the above formula, as shown in Figure 4

In the figure L=L _o -M, thus the balance equation of the phase voltage of the equivalent one-phase circuit is obtained:

According to the motor theory, the equation of back EMF and speed:

E=K _e ω (s8)

In the formula, K _e is the back electromotive force constant of the motor (V s/rad)

From the formulas (s7) and (s8), it can be seen that when the motor is started, the angular velocity is very small, the back electromotive force is very small, and the product inductance is much smaller than the resistance value, so the phase voltage and current are proportional. Right now:

U＝Ri (s9)

Therefore, in engineering, the voltage and current can be adjusted to achieve the purpose of detecting friction torque by adjusting the starting voltage.

(3) Design of acceleration law for variable voltage start-up:

The successful realization of the open-loop acceleration of the gyro motor is affected by factors such as the motor load torque, applied voltage, acceleration curve and moment of inertia. Because the variable voltage start-up control needs to change the applied voltage, the unreasonable acceleration curve will cause the motor to fail to start, and the start-up failure at this time is not the reason for the large static friction force. In order to ensure the reliable start of the motor, the following analysis of the dynamic pressure air bearing gyro The starting rule of the motor.

Firstly, the characteristic parameters of the motor are determined, and the wind resistance M _f and the friction torque M _m are considered in the rotation of the motor, which are respectively

M _f =aω ² (s10)

M _m = bω (s11)

where a and b are the wind resistance moment coefficient and the friction moment coefficient respectively.

When the constant voltage is started, the acceleration start voltage is 12V.

The voltage balance equation for motor starting is

Because the motor phase inductance is much smaller than the motor phase resistance, the above formula can be approximated as

The electromagnetic torque of the motor is

The torque balance equation when the motor starts is

Substituting the relevant parameter values of the motor and solving the above differential equation, the starting curve of the motor can be obtained as shown in Figure 5. The partially enlarged diagram of the rotational speed curve is shown in Fig. 6(a) and Fig. 6(b). When the starting voltage is 12V, accelerating the motor according to the above curve can ensure the reliable start of the gyro motor.

When starting with variable voltage, it is necessary to design the acceleration law in starting with different voltages according to the method, so as to ensure that the product can be successfully started when starting at each voltage.

Based on the above theoretical analysis, the present invention provides a monitoring and screening control system for the bearing surface friction torque of a permanent magnet gyro motor. Computer; the tested permanent magnet gyroscope is installed on the test platform through the test tool;

The variable voltage power supply outputs a DC voltage signal with a corresponding amplitude to the permanent magnet gyro controller according to the starting voltage command, and the voltage amplitude can be set;

The measurement and control computer sets the starting voltage range, and sends the starting voltage command to the variable voltage power supply; loads the preset variable voltage starting acceleration law parameters into the permanent magnet gyro controller, and collects the telemetry digital value of the motor speed uploaded by the permanent magnet gyro controller , through this digital quantity, judge whether the gyro motor is started, if the motor starts successfully, control the motor to stop; set different starting voltage ranges to perform multiple motor starts, find the minimum starting voltage value, and calculate the minimum current value according to the minimum starting voltage value , the friction torque is calculated according to the minimum current value;

The permanent magnet gyro controller converts the DC voltage signal output by the variable voltage power supply into three-phase alternating current according to the parameters of the variable voltage start-up acceleration law, and drives the measured permanent magnet gyro motor to start and rotate stably.

If the same starting voltage value is successful for N times of starting, it means that the current voltage value is greater than or equal to the minimum starting voltage value, lower the starting voltage value of the output of the transformer power supply, and start the motor repeatedly; , it means that the current voltage value is less than or equal to the minimum starting voltage value, increase the starting voltage value of the output of the transformer power supply, and start the motor repeatedly until the minimum starting voltage value is found.

The variable voltage startup acceleration rule parameters include acceleration time, step time of step acceleration, and motor acceleration frequency value for each step time.

The permanent magnet gyro controller includes a start control module, a three-phase inverter, a back EMF detection module, a commutation logic module and a motor speed stabilization control module;

The starting control module converts the variable voltage starting acceleration law parameters input by the measurement and control computer into the starting control square wave signal of the six-way motor commutation, and outputs it to the three-phase inverter, which will be used to realize the variable voltage starting of the gyro motor until the acceleration time maturity;

The three-phase inverter module inverts the DC voltage signal output by the variable voltage power supply into three-phase AC power, and outputs the three-phase AC power to the measured permanent magnet gyro motor to realize the rotation of the gyro motor;

The back EMF zero-crossing detection module collects the terminal voltage signal of the measured permanent magnet gyro motor winding, performs zero-crossing detection, and obtains the back EMF zero-crossing square wave signal related to the motor speed. After the acceleration time expires, the back EMF zero-crossing The square wave signal is output to the commutation logic module;

The commutation logic module commutates the back EMF zero-crossing square wave signal to obtain six motor control square wave signals. The control square wave signal is divided into two channels, one output to the motor speed stabilization control module, and the other output to the three-phase inverter Transformer;

The motor speed stabilization control module analyzes the motor control square wave signal output by the commutation logic module, and obtains the motor speed remote measurement digital value and outputs it to the measurement and control computer.

The duty ratio of the back EMF zero crossing square wave signal is 1/2, and the commutation logic module converts the back EMF zero crossing square wave signal into six motor control square wave signals with a duty ratio of one third.

The formula for calculating the minimum starting current value is:

U _min = Ri _min

Among them, U _min is the minimum starting voltage value, R is the phase resistance of the three-phase winding of the motor, and i _min is the minimum starting current value.

The formula for calculating the friction torque is:

M _m =K _T i _min

Among them, M _m is the friction torque, K _T is the torque constant of the motor, and i is the minimum starting current value.

The test platform is placed on a vibration-isolated foundation.

The present invention also provides a method for monitoring, screening and controlling the surface friction torque of the permanent magnet gyro motor bearing, the method comprising the following steps:

St1, install the tested permanent magnet gyroscope on the test platform through the test tooling,

St2. Load the preset variable voltage start acceleration law parameters into the permanent magnet gyro controller. The variable voltage start acceleration law parameters include acceleration time, step time of step acceleration, and motor acceleration frequency value of each step time ;

St3, set the initial start-up voltage of the transformer power supply output;

St4. Start the gyro motor according to the set voltage and acceleration rules. If the motor starts successfully, control the motor to stop;

St5, repeat step St4 N times, if N times of starting are successful, it means that the current voltage value is greater than or equal to the minimum starting voltage value, lower the starting voltage value of the output of the transformer power supply, repeat steps St4 ~ step St5, once there is a failure to start, It means that the current voltage value is less than or equal to the minimum starting voltage value, and the starting voltage value output by the transformer power supply is adjusted up, and steps St4 to Step St5 are repeated until the minimum starting voltage value is found;

St6. Calculate the minimum current value according to the minimum starting voltage value;

The formula for calculating the minimum starting current value is:

U _min = Ri _min

Among them, U _min is the minimum starting voltage value, R is the phase resistance of the three-phase winding of the motor, and i _min is the minimum starting current value.

St7. Calculate the friction torque according to the minimum current value.

The formula for calculating the friction torque is:

M _m =K _T i _min

Among them, M _m is the friction torque, K _T is the torque constant of the motor, and i is the minimum starting current value.

Example 1

Implementation steps of the present invention are as shown in accompanying drawing 1:

1. Build a starting current test platform:

As shown in Figure 2, build a starting current test platform, the platform is composed as follows:

Gyro component: The gyro component of the measured object is composed of several gyro instruments, and each gyro contains a gyro electrode bearing;

Special tooling for attitude testing: In order to study the friction distribution of gyro bearings under multiple attitudes, it is necessary to adjust the attitude by installing components on special tooling;

Stable Platform: Provides a stable test base; the platform is placed on a vibration-isolated foundation, and disturbances do not affect it.

Variable voltage power supply: externally supply the driving voltage of the gyro motor, and find the minimum starting voltage of the gyro by adjusting the voltage value.

Permanent magnet gyro control circuit: including start control module, three-phase inverter, back EMF detection module, commutation logic module and motor speed stabilization control module;

The starting control module converts the variable voltage starting acceleration law parameters input by the measurement and control computer into the starting control square wave signal of the six-way motor commutation, and outputs it to the three-phase inverter, which will be used to realize the variable voltage starting of the gyro motor until the acceleration time maturity;

The three-phase inverter module inverts the DC voltage signal output by the variable voltage power supply into three-phase AC power, and outputs the three-phase AC power to the measured permanent magnet gyro motor to realize the rotation of the gyro motor;

The back EMF zero-crossing detection module collects the terminal voltage signal of the measured permanent magnet gyro motor winding, performs zero-crossing detection, and obtains the back EMF zero-crossing square wave signal related to the motor speed. After the acceleration time expires, the back EMF zero-crossing The square wave signal is output to the commutation logic module;

The commutation logic module commutates the back EMF zero-crossing square wave signal to obtain six motor control square wave signals. The control square wave signal is divided into two channels, one output to the motor speed stabilization control module, and the other output to the three-phase inverter Transformer;

The motor speed stabilization control module analyzes the motor control square wave signal output by the commutation logic module, and obtains the motor speed remote measurement digital value and outputs it to the measurement and control computer.

Realize the start-up drive control function of the variable voltage gyro permanent magnet motor, and have an online programmable chip to realize the injection of acceleration law parameters.

Measurement and control computer: realize the upper computer communication.

2. Set the initial starting voltage:

After the platform is built, set the starting voltage of the initial variable voltage power supply.

3. Inject startup rule parameters

The parameters of the variable voltage start acceleration law are obtained from the acceleration curve of the constant voltage start motor; according to the method in the design of the variable voltage start acceleration law, the acceleration curve of the set voltage is drawn. The step time of forward acceleration is 50ms, and the motor acceleration frequency value of each step time is converted from the speed value on each 50ms curve to the motor frequency value.

The above three values constitute the parameters of the acceleration law. Through the host computer, the start-up acceleration law parameters including the acceleration time, the step time of step acceleration, and the motor acceleration frequency value of each step time are injected into the permanent magnet gyro control circuit.

4. Control motor start

Start the gyro motor according to the set voltage and acceleration rules. If the motor starts successfully, the motor is controlled to stop. Because the stop position of the gyro rotor is random in the bearing, in order to investigate the friction torque distribution in the entire bearing of the gyro motor, five consecutive starts are required. Successful starts for many times prove that the bearing friction torque is less than the set voltage value. If the motor fails to start, the voltage needs to be increased. The parameters of the start-up acceleration rule for injecting new voltage include acceleration time, step time of step acceleration, and the motor acceleration frequency value for each step time to restart until the minimum start-up voltage is found.

5. Record the starting voltage and calculate the friction torque

If the gyro starts successfully continuously, record the set voltage value, and calculate the minimum current value of the product according to the formula U _min = Ri _min . According to the design method M _m =K _T i _min of the minimum starting current method, calculate the friction torque value of the product.

6. Test the minimum starting voltage and friction torque under different postures

Due to the influence of gravity on the ground, the contact friction between the product rotor and the bearing is different in different postures. In order to obtain the distribution of friction force under different postures, it is necessary to change the posture of the components through special tooling and re-test the starting voltage.

7. Physical verification

A certain type of product uses six permanent magnet gyro motors G1-G6. The minimum starting current of the motors is tested twice before and after the ground environment test. The test posture is the motor shaft is horizontal, the motor shaft is upper right, and the motor shaft is lower left. The motor shaft horizontal criterion is <400mA, the criterion for the upper right of the motor shaft and the lower left of the motor shaft is <600mA, and the test results are shown in the table below.

Table 1 The minimum starting current test results of the product (unit: mA)

From the test results, the data on the upper right side of the motor shaft of the G4 gyro motor changed from 410mA to 830mA before and after the test, showing an obvious increasing trend, indicating that the static friction of the bearing surface has changed. Therefore, the G4 gyroscope is replaced with the stock gyroscope that meets the index, and the gyroscope is effectively monitored and screened by the minimum current starting method, which meets the model task requirements.

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention, and any person skilled in the art can use the methods disclosed above and technical content to analyze the present invention without departing from the spirit and scope of the present invention. Possible changes and modifications are made in the technical solution. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention, which do not depart from the content of the technical solution of the present invention, all belong to the technical solution of the present invention. protected range.

Claims (11)

1. The monitoring and screening control system for the surface friction torque of the permanent magnet gyro motor bearing, which is characterized in that it includes a test platform, a test tool, a tested permanent magnet gyro component, a variable voltage power supply, a permanent magnet gyro controller, and a measurement and control computer; the tested permanent magnet The gyro is installed on the test platform through the test tool; The variable voltage power supply outputs a DC voltage signal of a corresponding magnitude to the permanent magnet gyro controller according to the starting voltage command; The measurement and control computer sets the starting voltage range, and sends the starting voltage command to the variable voltage power supply; loads the preset variable voltage starting acceleration law parameters into the permanent magnet gyro controller, and collects the telemetry digital value of the motor speed uploaded by the permanent magnet gyro controller , through this digital quantity, judge whether the gyro motor is started, if the motor starts successfully, control the motor to stop; set different starting voltage ranges to perform multiple motor starts, find the minimum starting voltage value, and calculate the minimum current value according to the minimum starting voltage value , the friction torque is calculated according to the minimum current value; The permanent magnet gyro controller converts the DC voltage signal output by the variable voltage power supply into three-phase alternating current according to the parameters of the variable voltage start-up acceleration law, and drives the measured permanent magnet gyro motor to start and rotate stably. 2. The monitoring and screening control system of the permanent magnet gyro motor bearing surface friction torque according to claim 1, wherein if the same starting voltage value N times of starting are all successful, then it means that the current voltage value is greater than or equal to the minimum starting voltage value, and the adjustment is made downward. The starting voltage value output by the variable voltage power supply, start the motor repeatedly; once one of the N times of starting with the same starting voltage value fails, it means that the current voltage value is less than or equal to the minimum starting voltage value, increase the starting voltage value of the variable power supply output, and repeat Start the motor until the minimum starting voltage value is found, and the N is greater than or equal to 1. 3. the monitoring and screening control system of permanent magnet gyro motor bearing surface friction torque according to claim 1, it is characterized in that described variable voltage start-up acceleration rule parameter comprises acceleration time, the step time of step acceleration, each step length Time motor acceleration frequency value. 4. the monitoring screening control system of permanent magnet gyro motor bearing surface friction torque according to claim 1, it is characterized in that described permanent magnet gyro controller comprises starting control module, three-phase inverter module, back EMF detection module, Phase commutation logic module and motor speed stabilization control module; The start control module converts the variable voltage start acceleration law parameters input by the measurement and control computer into a start control square wave signal for six-way motor commutation, and outputs it to the three-phase inverter module until the acceleration time expires; The three-phase inverter module inverts the DC voltage signal output by the variable voltage power supply into three-phase alternating current, and outputs the three-phase alternating current to the measured permanent magnet gyro motor; The back EMF zero-crossing detection module collects the terminal voltage signal of the measured permanent magnet gyro motor winding, performs zero-crossing detection, and obtains the back EMF zero-crossing square wave signal related to the motor speed. After the acceleration time expires, the back EMF zero-crossing The square wave signal is output to the commutation logic module; The commutation logic module commutates the back EMF zero-crossing square wave signal to obtain six motor control square wave signals. The control square wave signal is divided into two channels, one output to the motor speed stabilization control module, and the other output to the three-phase inverter Transformer; The motor speed stabilization control module analyzes the motor control square wave signal output by the commutation logic module, and obtains the motor speed remote measurement digital value and outputs it to the measurement and control computer. 5. the monitoring and screening control system of permanent magnet gyro motor bearing surface friction torque according to claim 4, it is characterized in that the duty ratio of said back emf zero-crossing square wave signal is 1/2, and the commutation logic module will reverse The potential zero-crossing square wave signal is converted into a six-way motor control square wave signal with a duty cycle of one-third. 6. The monitoring and screening control system of the permanent magnet gyro motor bearing surface friction torque according to claim 1, wherein the calculation formula of the minimum starting current value is: U _min = Ri _min Among them, U _min is the minimum starting voltage value, R is the phase resistance of the three-phase winding of the motor, and i _min is the minimum starting current value. 7. the monitoring screening control system of permanent magnet gyro motor bearing surface friction torque according to claim 1, it is characterized in that the calculation formula of described friction torque is: M _m =K _T i _min Among them, M _m is the friction torque, K _T is the torque constant of the motor, and i is the minimum starting current value. 8. The monitoring and screening control system of permanent magnet gyro motor bearing surface friction torque according to claim 1, characterized in that the test platform is placed on a vibration-isolated foundation. 9. The monitoring and screening control method of the bearing surface friction torque of the permanent magnet gyro motor is characterized in that it comprises the following steps: St1, install the tested permanent magnet gyroscope on the test platform through the test tooling, St2. Load the preset variable voltage start acceleration law parameters into the permanent magnet gyro controller. The variable voltage start acceleration law parameters include acceleration time, step time of step acceleration, and motor acceleration frequency value of each step time ; St3, set the initial start-up voltage of the transformer power supply output; St4. Start the gyro motor according to the set voltage and acceleration rules. If the motor starts successfully, control the motor to stop; St5, repeat step St4 for N times, if the start is successful for N times, it means that the current voltage value is greater than or equal to the minimum start voltage value, lower the start voltage value of the output of the transformer power supply, repeat steps St4 ~ step St5, once there is a start failure, It means that the current voltage value is less than or equal to the minimum starting voltage value, and the starting voltage value output by the transformer power supply is adjusted up, and steps St4 to Step St5 are repeated until the minimum starting voltage value is found; said N is greater than or equal to 1; St6. Calculate the minimum current value according to the minimum starting voltage value; St7. Calculate the friction torque according to the minimum current value. 10. The monitoring and screening control method of the permanent magnet gyro motor bearing surface friction torque according to claim 9, wherein the calculation formula of the minimum starting current value is: U _min = Ri _min Among them, U _min is the minimum starting voltage value, R is the phase resistance of the three-phase winding of the motor, and i _min is the minimum starting current value. 11. the monitoring screening control method of permanent magnet gyro motor bearing surface friction torque according to claim 9, it is characterized in that the calculation formula of described friction torque is: M _m =K _T i _min Among them, M _m is the friction torque, K _T is the torque constant of the motor, and i is the minimum starting current value.

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