RU76181U1 - EMBEDDED CONTROL DEVICE AND ARCHIVING CONTROL RESULTS - Google Patents

Abstract

The utility model relates to electrical engineering, and in particular to devices for the built-in monitoring and forecasting of dead moves of mechanical transmissions of AC electric drives during their operation without dismantling mechanical transmissions and electric motors.

The utility model solves the problem of providing the possibility of archiving the results of the monitoring of dead moves of mechanical transmissions of AC electric drives during their operation

A device for integrated monitoring and archiving of the results of the monitoring of the deadlock of a mechanical transmission of an AC electric drive, comprising an AC motor connected to the load through a controlled mechanical transmission, a sensor for monitoring the deadlock of a mechanical transmission built into the stator winding of the electric motor, a peak amplitude detector, the input of which is connected to the sensor control, pulse shaper, the input of which is connected to the output of the peak amplitude detector, and the output is connected It is connected with the microcontroller port line configured as an input, while an eight-bit PIC16F877 microcontroller with EEPROM data memory, a microcontroller control unit and a nine-digit seven-segment character indicator ALS356A, five microcontroller port lines configured as input-output are connected to the unit and connected to the control unit seventeen microcontroller port lines configured as an output are connected to a nine-digit seven-segment sign indicator.

Illustrations - 2.

Description

The utility model relates to electrical engineering, and in particular to devices for the built-in monitoring and forecasting of dead moves of mechanical transmissions of AC electric drives during their operation without dismantling mechanical transmissions and electric motors.

The analogue is known - Patent for utility model RU 66869 U1, IPC Н02К 7/10, Н02Р 5/00. DC electric drive with a device for integrated monitoring of the dead-end of mechanical transmission / Agafonov Yu.M., Akinshin RN, Ankudinov K.A. et al. // Bull. No. 27 dated 09/27/2007. The analogue contains: a direct current electric motor, which through a controlled

mechanical transmission connected to the load; a sensor connected in series in the armature winding of a DC motor is an active resistance with a value two to three orders of magnitude less than the resistance of the armature winding, which eliminates the influence of the sensor on the operation mode of the DC motor; the sensor is connected to a pulse shaper, consisting of a differentiating circuit and an amplifier-limiter; the pulse shaper is connected to an Atmel microcontroller of the ATtiny28L series, which calculates the dead time of mechanical transmission of a direct current electric drive α according to a predetermined algorithm and displays its value on a four-digit sign indicator of the ALS329B series with an accuracy of one thousandth of a degree:

where Ω _n is the nominal rotation speed of the DC motor [rpm] (taken from the technical documentation and recorded in the FLASH memory of the microcontroller programs);

T _mx is the time of selection of the dead-end of the mechanical transmission [s] (calculated by the microcontroller and the data memory is entered in its SRAM);

T _TW - electromechanical time constant of a DC motor [s] (taken from the technical documentation and recorded in the FLASH memory of the programs of the microcontroller).

The disadvantages of the analogue:

1) it is impossible to use the built-in control device used in the analogue to measure the dead moves of mechanical gears of electric drives of alternating current α;

2) there is no possibility of archiving the results of the control of the dead stroke of the drive during operation, which are necessary when predicting the failure of a mechanical transmission.

Known prototype - The decision to grant a patent for a utility model dated January 17, 2008 by application No. 2007146019/22 (050435) dated December 13, 2007. AC electric drive with built-in control device / Akinshin N.S., Ankudinov K.A., Ankudinov A.I. and etc. //. The prototype contains: an alternating current motor, which is connected to the load through a controlled mechanical transmission; the sensor connected in series in the stator winding of the AC motor is an active resistance with a value two to three orders of magnitude lower than the resistance of the stator winding, which eliminates the influence of the sensor on the operation mode of the AC motor; the sensor is connected to a peak amplitude detector, the output of which is connected to the input of the pulse shaper, consisting of a differentiating circuit and an amplifier-limiter; the pulse shaper is connected to the Atmel microcontroller of the ATtiny28L series, which calculates the dead time of the mechanical transmission of the AC electric drive α according to the same expression as for the DC electric drive, expression (1) and displays its value on the four-digit sign indicator of the ALS329B series with an accuracy of one thousandth fractions of a degree. In the prototype, T _dv is substituted into expression (1) - the electromechanical time constant of an alternating current electric motor [s] (taken from the technical documentation and recorded in the FLASH memory of the microcontroller programs).

The prototype is devoid of the first drawback of the analogue, but its significant drawback remains - the lack of the possibility of archiving the results of monitoring the dead movement of the AC electric drive during operation, which are necessary when predicting mechanical transmission failures.

The proposed utility model solves the problem of providing the possibility of archiving the results of the monitoring of the dead moves of mechanical transmissions of AC electric drives during their operation, which are used in predicting the output time of a quantity

dead gear mechanical transmission out of range. Why, in the built-in control device, at each measurement of the mechanical transmission deadlock, archiving is carried out:

- firstly, the magnitude of the measured dead stroke of a mechanical transmission;

- secondly, the operating time of the electric drive from the beginning of operation until the moment of measuring the dead movement of the mechanical transmission.

This object is achieved by the fact that in the device for the built-in monitoring and archiving of the results of the control of the dead mode of mechanical transmission of an AC electric drive, containing an AC motor connected to the load through a controlled mechanical transmission, a sensor for monitoring the dead movement of a mechanical transmission built into the stator winding of the electric motor, peak amplitude a detector whose input is connected to a control sensor, a pulse shaper whose input is connected to the pico output amplitude detector, and the output is connected to the microcontroller port line configured as input, an eight-bit PIC16F877 microcontroller with EEPROM data memory, a microcontroller control unit and a nine-digit seven-segment sign indicator ALS356A, five lines of the microcontroller port configured as an input-output control unit are introduced and seventeen microcontroller port lines configured as an output are connected to a nine-digit character indicator.

Due to the inclusion of the PIC16F877 series microchip eight-bit microcontroller in the device, which has in its structure FLASH program memory, SRAM data memory and EEPROM data memory (this memory provides recording, overwriting and storage of information in the on state and information storage in the microcontroller de-energized state), nine-bit the seven-segment iconic indicator ALS356A and the microcontroller control unit provide the opportunity

archiving the results of the control of the dead moves of mechanical transmissions of AC electric drives, which allowed:

- firstly, archive (save) in the EEPROM of the microcontroller data memory each numerical value of the measured values of the mechanical gears deadlocks during the entire operation cycle of the AC electric drive;

- secondly, archive (save) in the EEPROM of the microcontroller data memory the time the alternating current electric drive worked from the beginning of operation to the moment of each measurement of the mechanical transmission dead-end;

- thirdly, to output information on the magnitude and time of measurement of the dead moves of mechanical transmission, archived in the EEPROM of the microcontroller data memory, to a nine-digit seven-segment sign indicator.

In addition, the Atmel ATtiny28L microcontroller and the four-digit sign indicator ALS329B are excluded from the device (they are not able to fulfill the tasks assigned to the utility model).

Figure 1 shows a block diagram of a device for integrated monitoring and archiving of control results; figure 2 - timing diagrams of the operation of the device.

The device for integrated monitoring and archiving of the results of the monitoring of the dead-end of a mechanical transmission of an AC electric drive contains (FIG. 1): an AC electric motor 1, which is connected to a load 3 through a controlled mechanical transmission 2; a sensor 4 is sequentially included in the stator winding of electric motor 1 — active resistance with a value two to three orders of magnitude less than the resistance of the stator winding of the electric motor, which excludes the influence of sensor 4 on the operation mode of electric motor 1; the sensor 4 is connected to the input of the peak amplitude detector 5, assembled according to a typical circuit; the output of the peak amplitude detector 5 is connected to the input of the pulse shaper

6, consisting of a differentiating circuit and an amplifier - limiter; the output of the pulse shaper 6 is connected to the microcontroller 7 of the company Microchip PIC16F877 series with EEPROM data memory; microcontroller 7 calculates the deadlock according to the given algorithm (1), displays its value in the four least significant bits of the nine-digit seven-segment sign indicator 8 of the ALS356A series with an accuracy of one thousandth of a degree and stores the measured numerical value of the deadlock and its measurement time in the EEPROM from the beginning of operation of the AC electric drive, which is displayed in the five high-order bits of indicator 8; the control unit 9 of the microcontroller 7, provides information on the magnitude and time of measuring the dead moves of the mechanical transmission from the EEPROM of the microcontroller 7 data memory to a nine-digit seven-segment sign indicator 8 in various operating modes of the device.

The device is a built-in control and archiving of control results (figure 1) works in various modes and as follows:

1. During the commissioning of the electric drive (figure 1) in the FLASH memory of the programs of the microcontroller 7 from the control unit 9 are recorded passport data: the nominal rotation speed Ω _n [rpm] and the electromechanical time constant of the AC electric motor T _dv [C].

2. In the operating mode, in most cases, turning on the electric drive to perform the working functions is not accompanied by a measurement of the dead movement of the mechanical transmission 2, since the magnitude of the dead travel changes slowly as the mechanical transmission deteriorates during operation. The control unit 9 in this mode by default sets up the control device (Fig. 1) only to calculate the operating time of the drive in this cycle, which is recorded in the SRAM of the data of the microcontroller 7, and when disconnected from the operation of the drive is summed

with the previous operating time of the drive from the beginning of operation and is archived (overwritten) in the EEPROM data memory of the microcontroller 7 for storage.

3. Measurement mode. Before turning on the device (Fig. 1), the dead-end of mechanical transmission 2 is set to the maximum position (as in the analogue and the prototype) and power is supplied to the peak amplitude detector 5, pulse shaper 6, and microcontroller 7 (nine-digit sign indicator 8 is powered by the microcontroller 7). From the control unit 9 to the microcontroller 7 are supplied control signals that specify the mode of measurement of the free movement. At time t ₁ (Figure 2), the following processes occur: the AC electric motor 1 starts up and an alternating inrush current pulse appears in its stator winding, which creates an alternating voltage pulse at sensor 4 with amplitude u ₄ (t ₁ ) = U _4max arriving at the peak amplitude detector 5, which detects the signal front from the sensor 4 and supplies the output signal of the peak amplitude detector u ₅ (t ₁ ) = U _5max to the pulse shaper 6, which, in turn, generates a short pulse u ₆ (t ₁₎ = U _6max, supplied to the mic controller 7; the microcontroller 7 is included in the work and begins the countdown of the time of selecting the dead-end of the mechanical transmission T _mx and recording its current value in the SRAM data memory. In the time interval from t ₁ to t ₂ (FIG. 2), the following physical processes occur: the alternating current electric motor 1 rotates, the alternating starting current of the stator winding and the alternating voltage at the sensor 4 u ₄ (t) decrease exponentially; the low-speed shaft of the mechanical transmission 2 remains stationary, since the selection of the back stroke occurs, but it has not yet been selected; the voltage at the output of the peak amplitude detector 5 u ₅ (t) decreases exponentially, and the voltage at the output of the shaper 6 is zero u ₆ (t) = 0; microcontroller 7 continues

the countdown of the selection of the deadlock T _MX and stores its current value in its RAM data SRAM. At time t ₂ (FIG. 2), the following processes occur: the selection of the dead-end of mechanical transmission 2 is completed and the low-speed shaft of mechanical transmission 2 and load 3 come into rotation; the load on the alternating current motor 1 increases stepwise and an alternating inrush current pulse appears again in its stator winding, which creates an alternating voltage pulse at the sensor 4 u ₄ (t ₂ ) = U _4max , which arrives at the peak amplitude detector 5, which detects the signal front with sensor 4 and sends a signal u ₅ (t ₂ ) = U _5max to the pulse shaper 6, which, in turn, generates a short pulse u ₆ (t ₂ ) = U _6max , which arrives at the microcontroller 7; the microcontroller 7 ends the countdown of the selection of the dead time of the mechanical transmission T _mx and stores its value in the SRAM data memory in the dimension [s]; Further, according to the algorithm that implements expression (1), the microcontroller 7 for a time not exceeding ten milliseconds calculates the dead time of the mechanical transmission of the electric drive α and archives (writes) its value to its EEPROM data memory. The measurement mode is fleeting (it is fractions - units of a second) and therefore is not taken into account in the total operating time of the drive from the beginning of its operation. This ends the measurement mode, but it is usually accompanied by the already described operating mode, where the counting and archiving of the drive’s operating time continues.

4. The information output mode (Fig. 1) is provided by the supply of control signals: from the control unit 9 to the microcontroller 7 along five port lines configured as an input - output; from microcontroller 7 to a sign indicator 8 over seventeen port lines configured as an output. This mode provides a consistent display on the sign indicator 8 of all measured during operation operation values of the dead moves a and the corresponding operating time of the drive from the beginning

operation until the moment of the measurement in question, which are archived in the EEPROM of the data memory of the microcontroller 7. Moreover, the four least significant digits of the sign indicator 8 show the deadlock a to the nearest thousandth of a degree, and the five most significant digits indicate the corresponding operating time of the AC drive from the beginning of operation with accuracy to tenths of an hour.

Introduction to the device for integrated monitoring and archiving of the results of the monitoring of the dead-end of mechanical transmission of an AC electric drive: an eight-bit microchip 7 of Microchip PIC16F877 series, which has in its structure FLASH program memory - 8 Kbytes, SRAM data memory - 368 bytes and EEPROM data memory - 256 bytes, control unit 9 by microcontroller 7 and a nine-digit seven-segment sign indicator 8 of the ALS356A series provided:

1) archiving (storing) in the EEPROM memory of the microcontroller of the numerical values of the measured values of the deadlocks of a mechanical transmission during the entire operation cycle of an AC electric drive;

2) archiving (saving) in the EEPROM of the memory of the microcontroller during the operating time of the AC electric drive from the beginning of operation until each moment of measuring the dead stroke of the mechanical transmission;

3) the output of information about the magnitude and time of measuring the deadlocks of the mechanical transmission of the AC electric drive, archived in the EEPROM of the microcontroller's data memory, to the nine-digit seven-segment sign indicator, where the four least significant bits indicate the deadlock α, and the five senior bits indicate the corresponding operating time of the electric drive with the beginning of operation and up to the moment of measuring α, which, as you know, is used in predicting failures of mechanical gears.

Claims (1)

A device for integrated monitoring and archiving of the results of the monitoring of the deadlock of a mechanical transmission of an AC electric drive, comprising an AC motor connected to the load through a controlled mechanical transmission, a sensor for monitoring the deadlock of a mechanical transmission built into the stator winding of the electric motor, a peak amplitude detector, the input of which is connected to the sensor control, pulse shaper, the input of which is connected to the output of the peak amplitude detector, and the output is connected It is connected with a microcontroller port line configured as an input, characterized in that an eight-bit PIC16F877 microcontroller with EEPROM data memory, a microcontroller control unit and a nine-digit seven-segment indicator LED ALS356A, five microcontroller port lines configured as an input-output are connected to the device, connected to the control unit , and seventeen microcontroller port lines configured as an output are connected to a nine-digit seven-segment character indicator.