RU72586U1 - TWO-LINK DC ELECTRIC DRIVE WITH BUILT-IN CONTROL DEVICE - Google Patents

Abstract

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

A useful model solves the following problems: reducing the calculation time of the dead moves of a two-link mechanical transmission by a thousand times; the exception of manual calculations of dead moves and the indication of their values in degrees to the nearest thousandth of a degree; simplified design and increased reliability of the device.

A two-link direct current electric drive with a built-in control device, comprising a direct current electric motor connected to the load through a two-link mechanical transmission, a two-link mechanical transmission deadlock control sensor, a built-in electric motor, a pulse shaper, the input of which is connected to the deadlock control sensor, while microcontroller PIC16F873 and nine-digit seven-segment sign indicator ALS356A, one line of the microcontroller port configured as input d is connected to the output of the pulse shaper, and the sixteen lines port configured as an output, connected to the nine digits seven segment character display.

Illustrations - 2.

Description

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

A well-known analogue is “DC Electric Drive” (copyright certificate SU 1277301 A1, IPC Н02К 11/00, 7/10, Bull. No. 46 dated December 15, 86), containing: a single-link mechanical transmission with a working load; a direct current drive electric motor, in the anchor winding of which a sensor is connected in series - active resistance with a magnitude two orders of magnitude less than the resistance of the motor armature winding; pulse shaper; electronic switch; logic circuit “And” on two inputs; pulse generator and counting circuit. The analogue measures the time taken to select the backlash and, using the formula, manually calculates the backlash of a single-link mechanical transmission.

The analogue has the following main disadvantages:

1) there is no possibility of measuring the dead moves of two-link mechanical gears;

2) a large investment of time (tens of seconds) for calculating the backlash even of a single-link mechanical transmission according to the formula manually, which increases the likelihood of obtaining calculation errors;

3) the high complexity of the design of a single-link mechanical transmission deadlock control device — these are built on discrete radio elements: a pulse shaper, an electronic switch, a two-input logic circuit “I”, a pulse generator and a counting circuit;

4) low reliability, determined by the high complexity of the design of the device for the built-in control of the dead movement of a single-link mechanical transmission of an electric drive.

The closest technical solution - the prototype, is a "DC electric drive with a two-link mechanical transmission" (copyright certificate SU 1410250 A1, IPC Н02Р 5/00, Bull. No. 26 dated 07.15.88), containing: two-link mechanical transmission with a working load ; DC drive electric motor, in the anchor winding of which a deadlock control sensor is connected in series - active resistance with a magnitude two orders of magnitude less resistance

motor armature windings; pulse shaper; two triggers; two logical circuits “NOT”; pulse generator; two logical circuits “AND” on three inputs; two counting circuits. The prototype separately measures the time of selection of the dead moves of the first (high-speed) link α ₁ and the second (low-speed) link α _{2 of the} two-link mechanical transmission, and the formulas for calculating manually the dead moves α ₁ and α ₂ are of the form:

where Ω _n is the nominal speed of rotation of the electric motor [rpm];

n ₁ is the number of pulses calculated by the first counting circuit used to calculate α ₁ ;

n ₂ is the number of pulses calculated by the second counting circuit used to calculate α ₂ ;

N is the gear ratio of the first (high-speed) link of a two-stage mechanical transmission from input to output of the link;

T _and - the pulse repetition period of the pulse generator [s];

T _TW - electromechanical time constant of the electric motor [s].

The prototype is devoid of the first drawback of the analogue, but the remaining three drawbacks are even more inherent in the prototype, and with the current level of development of microprocessor circuitry, these drawbacks become significant:

1) a large investment of time (tens of seconds) for calculating the dead moves of the first link α ₁ and the second link α _{2 of a} two-link mechanical transmission according to formulas (1) and (2) manually, which increases the likelihood of a calculation error;

2) the high complexity of the design of the device for monitoring the deadlocks α ₁ and α _{2 of a} two-link mechanical transmission - these are built on discrete radio elements: pulse shaper; two triggers; two logical circuits “NOT”; pulse generator; two logical circuits “AND” on three inputs; two counting schemes (the number of blocks is twice as much as in the analogue);

3) low reliability, determined by the high complexity of the design of the device for the integrated monitoring of the deadlocks α ₁ and α ₂ two-link mechanical transmission of the electric drive.

The proposed utility model solves the following problems: reducing the calculation time of the dead moves α ₁ and α _{2 of a} two-link mechanical transmission by a thousand times; the exception of the manual calculation of the dead moves α ₁ and α ₂ and the indication of their values in degrees accurate to the thousandth of a degree; simplified design and increased reliability of the device.

The objective is achieved in that in a two-tier DC motor with a device built-in test α ₁ and α _2, comprising a DC motor connected to the load through a two-tier mechanical transmission, a sensor monitoring the dead strokes articulated power transmission incorporated in the motor, a pulse generator, the input which is connected to the deadlock control sensor, a microcontroller and a nine-digit seven-segment sign indicator, one line of the microcontroller port, on constructed as an input, it is connected to the output of the pulse shaper, and sixteen port lines configured as an output are connected to a nine-digit seven-segment sign indicator.

Due to the inclusion in the device of a microcontroller operating according to a given algorithm and a nine-digit seven-segment sign indicator, the need to calculate the dead moves of the first link α ₁ and second link α _{2 of a} two-link manual transmission by formulas (1) and (2) is eliminated, which required time in tens of seconds microcontroller

calculates the measured value of the dead strokes α ₁ and α ₂ at a predetermined algorithm automatically at the end of the measurement process, and displays the values on a landmark nine digits seven segment display to within a thousandth of a degree, spending up to ten milliseconds. In addition, nine prototype blocks made on discrete radio elements were excluded from the device: two triggers; two logical circuits “NOT”; pulse generator; two logical circuits “AND” on three inputs; two counting circuits. The measures taken have reduced complexity and increased the reliability of the device for measuring dead moves.

Figure 1 shows a block diagram of a two-link DC drive with a built-in control device (the deadlock of the spirit of the links of a two-link mechanical transmission is controlled), Fig.2 is a timing diagram of the operation of the device.

A two-link direct current electric drive with a built-in control device (Fig. 1), where the deadlifts of two links of a two-link mechanical transmission are monitored, comprises: a direct current electric motor 1, which is connected to the load 3 through a controlled two-link mechanical transmission 2; in the anchor winding of electric motor 1, a deadlock control sensor is sequentially included 4 - active resistance (current shunt) with a value of two to three orders of magnitude less than the resistance of the armature winding, which excludes the influence of the deadlock control sensor 4 on the operation mode of electric motor 3; the deadlock control sensor 4 is connected to the input of the pulse shaper 5, consisting of a differentiating circuit and an amplifier - limiter; the output of the pulse shaper 5 is connected to the Microchip microcontroller 6 of the PIC16F873 series, which calculates the dead moves of the first (high-speed) link and the second (low-speed) link of the two-link mechanical transmission according to the specified algorithm and displays their values on a nine-digit seven-segment sign indicator 7 of the ALS356A series with an accuracy of thousandth of a degree (the upper four digits highlight α ₁ and the lower four

discharge - α ₂ , the fifth discharge is separation and not used in the device, the ninth and fourth digits with a decimal point show units of degrees, and the sixth and first digits show thousandths of degrees of deadlocks α ₁ and α ₂ , respectively.

Two-link DC drive with a built-in control device (figure 1) works as follows. Before turning on the device in operation, the dead strokes of the two-link mechanical transmission 2 are set to the maximum position (as in the prototype), power is supplied to the pulse shaper 5 and microcontroller 6 (nine-digit seven-segment sign indicator 7 is powered by microcontroller 6). At time t ₁ (Fig. 2), the following processes occur: the electric motor 1 starts up and an inrush current pulse arises in its armature winding, which creates the first voltage pulse at the deadlock monitoring sensor 4 u ₄ (t ₁ ) = U _4max , arriving at the pulse shaper 5; the pulse shaper 5 produces the first short pulse u ₅ (t ₁ ) = U _5max supplied to the microcontroller 6; the microcontroller 6 is included in the work and begins the countdown time for the selection of the dead stroke of the first link α ₁ two-link mechanical transmission T _mx1 . In the time interval from t ₁ to t ₂ (Figure 2) the following physical processes take place: the motor 1 comes into rotation, the starting of the armature current and voltage at the sensor control dead strokes 4 u ₄ (t) decreases exponentially; the output shaft of the first link of the two-link mechanical transmission 2 remains stationary, since there is a choice of the dead stroke of the first link α _{1 of the} two-link mechanical transmission, but it has not yet been selected; the voltage at the output of the pulse shaper 5 is zero u ₅ (t) = 0; the microcontroller 6 counts the time of selection of the dead stroke of the first link α ₁ two-link mechanical transmission T _mx1 . At time t ₂ (Fig. 2), the following physical processes occur: the selection of the dead motion of the first link α _{1 of the} two-link mechanical transmission 2 is completed, the output shaft of the first

link (aka the input shaft of the second link) of a two-link mechanical transmission 2; the load on the electric motor 1 increases stepwise a second time and a second inrush current pulse appears in its armature winding, which creates a second voltage pulse at the sensor 4 u ₄ (t ₂ ) = u _4max , which enters the pulse shaper 5; pulse generator 5 generates a second short pulse u ₅ (t ₂₎ = U _5max, supplied to the microcontroller 6; the microcontroller 6 stops the countdown of the dead time selection of the first link α _{1 of the} two-link mechanical transmission T _max1 and stores its value in its SRAM data memory in the dimension [s]; in addition, the microcontroller 6 starts the countdown time of the selection of the dead run of the second link α ₂ two-link mechanical transmission T _mx2 . The following physical processes occur in the time interval from t ₂ to t ₃ (Fig. 2): the electric motor 1 continues to rotate, the output shaft of the first link (input shaft of the second link) of the two-link mechanical transmission comes into rotation, the starting current of the armature and the voltage at the sensor 4 u ₄ (t) decrease exponentially; the output shaft of the second link of the two-link mechanical transmission 2 and the load 3 remains stationary, since the selection of the dead run of the second link α ₂ , but it has not yet been selected; the voltage at the output of the pulse shaper 5 is zero u ₅ (t) = 0; the microcontroller 6 counts the time of the selection of the dead stroke of the second link α ₂ two-link mechanical transmission T _mx2 . At time t ₃ (Fig. 2), the following physical processes occur: the selection of the dead run of the second link α _{2 of the} two-link mechanical transmission 2 is completed, the output shaft of the second link of the two link of the two-link mechanical transmission 2 and load 3 come into rotation; the load on the electric motor 1 increases stepwise for the third time and a third inrush current pulse appears in its armature winding, which creates a third voltage pulse at the dead- _travel sensor 4 u ₄ (t ₃ ) = U _4max , which enters the pulse shaper 5; pulse shaper 5 generates a third short pulse u ₅ (t ₃ ) = U _5max , arriving at

microcontroller 6; the microcontroller 6 stops the countdown of the dead time selection of the second link α _{2 of the} two-link mechanical transmission T _mx2 and stores its value in the SRAM of the data memory in the dimension [s]. Thus, the values of _Tmx1 and _{Tmx2 are} measured and recorded in the SRAM of the data memory of the microcontroller 6; taking into account formulas (1) and (2), the expressions for calculating the dead moves of the first link α ₁ and the second link α _{2 of the} two-link mechanical transmission by the microcontroller 6 take the form:

Where Ω _n - rated speed of rotation of the electric motor [rpm];

N is the gear ratio of the first (high-speed) link of a two-stage mechanical transmission from input to output of the link;

T _dv - electromechanical time constant of the electric motor [s];

T _mx1 and T _mx2 - the time of selection of the dead moves of the first link α ₁ and the second link α ₂ two-link mechanical transmission, respectively [s].

For electric motor 1, the values of the nominal rotation speed Ω _n [rpm] and the electromechanical time constant T _dv [s] are constant and known values, they are taken from the technical documentation for the electric motor 1 and recorded in advance in the FLASH memory of the programs of the microcontroller 6, and the values of T _mx1 and T _mx2 is located in the SRAM of the data of the microcontroller 6, which, according to an algorithm that implements expressions (3) and (4), calculates the dead moves of the first link α ₁ and the second link α _{2 of the} two-link mechanical transmission in a time not exceeding ten mil liseconds and highlights it on a nine-digit seven-segment sign indicator 7, where the highest four digits indicate α ₁ and the lower four digits indicate α ₂ , and in the four-digit values α ₁ and α ₂ in the senior digits

units are displayed, and in the younger ones - thousandths of degrees of dead moves.

Application in the device of an eight-bit microchip 6 microcontroller from PIC16F873 series with 4 KB flash program memory, 192 byte SRAM data memory, 128 byte EEPROM data and ALS356A series nine-digit seven-digit sign indicator (one microcontroller 6 port line configured as an input, connected to the output of the pulse shaper 5, and sixteen port lines configured as an output connected to a nine-digit seven-segment sign indicator 7) provided:

1) reducing the calculation time of the dead moves of a two-link mechanical transmission by a thousand times, since the microcontroller performs all the calculations automatically at the end of the process of measuring dead moves in a time not exceeding ten milliseconds (in the prototype this procedure is performed manually and takes tens of seconds or more) and immediately displays the measurement result of the first link moves the dead α ₁ and α ₂ of the second link of the two-stage mechanical transmission in degrees with the accuracy of one thousandth of a degree to nine digits with misegmentnom landmark indicator.

2) reducing the complexity of the design, since the block diagram of the utility model (Fig. 1) does not contain nine prototype blocks (two triggers, two “NOT” logic circuits, a pulse generator, two “AND” logic circuits with three inputs, two counting circuits performed on discrete radio elements), but performs more complex functions;

3) increasing the reliability of the utility model by reducing the complexity of the design and eliminating the need for manual calculations.

Claims (1)

A two-link direct current electric drive with a built-in control device, comprising an electric motor connected to the load through a two-link mechanical transmission, a deadlock control sensor of a two-link mechanical transmission, built-in to the electric motor, a pulse shaper, the input of which is connected to the deadlock control sensor, characterized in that the device introduced an eight-bit PIC16F873 microcontroller and a nine-bit seven-segment sign indicator ALS356A, one line of the microcontroller port configured The same as input is connected to the output of the pulse shaper, and sixteen port lines configured as output are connected to a nine-digit seven-segment character indicator.