RU2302073C1 - Electric drive - Google Patents

Abstract

FIELD: electrical engineering; angular velocity stabilizing systems built around phase locking circuit.

SUBSTANCE: proposed device has six flip-flops, two EXCLUSIVE OR gates, and four multiplexers used for converting signal arriving from shaft speed/position photoelectric pulse sensor. Above-mentioned components ensure desired noise immunity of device, in particular on long communication lines between motor whose shaft mounts photoelectric-pulse speed/position sensor and control device.

EFFECT: enlarged functional capabilities due to enhanced noise immunity of control coordinate measuring channel.

1 cl, 5 dwg

Description

The invention relates to electrical engineering and can be used in angular velocity control systems, in particular electric drives, built on the basis of the principles of phase synchronization.

A number of electric drives are known [1], built on the basis of digital speed meters, the main element of which are photo-pulse sensors [2, 3]. In most digital speed meters, its value is determined by counting the number of sensor pulses for a fixed period of time or by measuring the duration of one or more periods of the signal of the photopulse sensor [1, 3]. The first method for constructing digital speed meters is characterized by a low measurement error in the region of large angular velocity values. In the second method, as the measured speed increases, the accuracy of its measurement decreases. In the zone of low and low angular velocities, even when measuring transducers with high resolution are used, the quantization period of their output signal reaches such large values that providing a small error in stabilization of the adjustable coordinates by counting the number of pulses or measuring the period of the sensor signal becomes practically impossible. Therefore, in precision electric drive systems, systems are used that are closed not by the angular velocity of the shaft, but by the deviation of its position from the set value. As shown in [6], this principle of constructing a control system provides ideal astatism in terms of the average value of the measured angular velocity, and therefore, a small error in its stabilization. Technically, this principle is implemented by identifying the phase mismatch of the frequency signals of the reference and feedback coming from the position sensor with a pulse output signal. All the advantages of phase-locked systems can only be fully achieved with a high input frequency. Closest to the proposed device is a DC electric drive [4]. The electric drive contains a motor with a shaft connected to a speed meter. Anchor motor winding is connected to the outputs of the power converter. These outputs are included in the diagonal of the transformer bridge of the power converter. The modulating and reversing inputs of the power converter are connected to the first and second outputs of the frequency-phase discriminator. The generator of the driving frequency is connected to the first input of the frequency-phase discriminator through the first frequency divider. The frequency-phase discriminator contains four triggers, the first and second elements "OR", the first and second elements "AND". The counting inputs of the first and second triggers are connected to the first input of the frequency-phase discriminator, the second input of which is connected with the counting inputs of the third and fourth triggers. The information inputs of the first and third triggers are associated with the outputs of the corresponding OR elements. Trigger reset inputs are connected to the output of the first AND element, the second input of which is connected to the output of the third trigger, the information input of the second trigger and the second input of the first OR element. The first input of the latter is connected to the first output of the frequency-phase discriminator, the output of the second trigger and the first input of the second element "AND". The second input of the second AND element is connected with the second output of the frequency-phase discriminator, the output of the fourth trigger and the second input of the OR element, the first input of which is connected to the first input of the first AND element, the output of the first trigger and the information input of the fourth trigger. The reset inputs of the second and fourth triggers are connected to the output of the second AND element.

The speed meter contains a photopulse speed sensor, a second and third frequency divider, four triggers and a multiplexer. The output of the multiplexer through the second frequency divider is connected to the second input of the frequency-phase discriminator. The first address input of the multiplexer is connected to the reset input of the second trigger of the speed meter and the output of the fourth trigger. The second address input of the multiplexer is connected to the output of the first trigger of the speed meter, the information and counting inputs of which are connected to the first and second outputs of the photo-pulse speed sensor. The information input of the fourth trigger is connected to the output of the second trigger. Its counting input is connected to the second output of the photopulse speed sensor. The counting input of the fourth trigger, the second and fourth information inputs of the multiplexer are connected to the output of the third trigger. The input of the third trigger is connected to the output of the third frequency divider and the control input of the multiplexer. A logic zero signal is applied to the first information input of the multiplexer, and a logic one to the third. The input of the third frequency divider is connected to the generator of the driving frequency.

Such an electric drive provides a wide range of angular velocity control and a small error in its stabilization. The stabilization error of the controlled coordinates is determined by the capabilities of the used photo-pulse position sensor, namely its resolution. However, it may not be enough to obtain high quality performance of the electric drive. In addition, in the known device, it is possible to skip one or more edges of the input signal when they are followed with an interval shorter than the period of the output signal of the third frequency divider 27. It is also possible the appearance of false pulses in the presence of common-mode interference arising at the moments of change of one of the output signals of the photo-pulse speed sensor.

The technical result of the invention is to increase the noise immunity of the measured coordinate measurement channel. To achieve this goal, the proposed device for converting the signal of a photopulse speed / shaft position sensor uses six triggers, two EXCLUSIVE OR elements, and four multiplexers. The use of these elements provides an increase in the noise immunity of the device, especially with extended communication lines between the engine, on the shaft of which a photo-pulse speed / position sensor is installed, and the control device.

To do this, means are introduced into the known device that provide protection against missing moments of changes in the output signals of the sensor and common-mode interference arising in the communication lines.

To implement the proposed features, six triggers (T5-T10), two EXCLUSIVE OR elements, and four multiplexers have been introduced into the known device. Triggers T5-T7 and T8-T10 are included in the shift register scheme with the possibility of installation in a state determined by the operating conditions of the device. To do this, between the output and the information input of the pair of triggers (T5-T6), (T6-T7), (T8-T9) and (T9-T10) the elements "EXCLUSIVE OR" are included. The first inputs of the first and second EXCLUSIVE OR elements are connected to the output of trigger T8 and the counting input of the first trigger. The first inputs of the third and fourth EXCLUSIVE OR elements are connected to the output of the T10 trigger and the information input of the first trigger. The information inputs of the triggers T6 and T8 are connected to the first and second outputs of the photo-pulse speed sensor. Counting triggers (T5-T10) through the fourth divider are connected to the output of the generator of the driving frequency. In addition, compared with the prototype of the proposed device contains a simpler multiplexer, the address input of which is connected to the output of the third trigger, and the information inputs are connected to the outputs of the first and fourth triggers. In addition, the second input of the second divider is connected to the output of the third divider.

Figure 1 shows the functional diagram of the electric drive.

The electric drive contains a motor 1, with a photo-pulse speed sensor 8 connected to its shaft. Anchor winding of the motor 1 is connected to the outputs (5.3) and (5.4) of the power converter 5, made on a transistor in a bridge circuit, which makes it possible to change the polarity of the voltage supplying the motor 1. The modulating (5.1) and reversing (5.2) inputs of the power converter 5 are connected to the first (3.3) and second (3.4) outputs of the reversible frequency-phase discriminator 3. To the first input (3.1) of the frequency-phase discriminator 3 through the first a frequency divider 13 is connected to a reference frequency generator 4. The signal converter of the sensor 2 contains a second 6 and a third 7 frequency dividers, a multiplexer 9 and four triggers (10-13). The output of the multiplexer 9 is connected to the resolution input of the second divider 6, the output of which is connected to the second (3.2) input of the frequency-phase discriminator 3. The counting input of the second divider 6 is connected to the input of the fourth trigger 13 and the output of the third divider 1, the input of which is connected to the driving frequency generator 4. The address input of the multiplexer 9 is connected to the reset input of the trigger 11, the output of the trigger. The output of the trigger 11 is connected to the information input of the trigger 12, the counting input of which is connected to the output of the fourth trigger 13 and the second information input of the multiplexer 9, the first information input of which is connected to the output of the first trigger 10. The counting inputs of the first 10 and second 11 triggers are connected to the output of the seventh trigger 17 and the first inputs of the first 18 and second elements "EXCLUSIVE OR". To the output of the generator 4 of the driving frequency through the fourth frequency divider 8 connected counting inputs of the triggers 15-17 and 20-22. The first and second outputs of the photopulse speed sensor 14 are connected to the information inputs of the triggers 15 and 20, respectively. The output of the trigger 15 is connected to the second input of the first EXCLUSIVE OR element 18, the output of which is connected to the information input of the trigger 16. The output of trigger 16 is connected to the second input of the second EXCLUSIVE OR element 19, the output of which is connected to the information input of the trigger 17. Trigger output 20 is connected to the second input of the third EXCLUSIVE OR element 23, the output of which is connected to the information input of the trigger 21. The output of the trigger 21 is connected to the second input of the fourth EXCLUSIVE OR element 24, the output of which is connected to the information ion trigger input 22, the output of which is connected to the first inputs of elements "exclusive OR" 23, 24 and the data input of the first flip-flop 10.

Figure 2-5 shows timing diagrams explaining the operation of the electric drive, where the numbers indicate the signals at the outputs of the corresponding elements of the device.

The device operates as follows.

The electric drive is a phase synchronization system in which the speed of the motor 1 is controlled by a power converter 5 as a function of phase mismatch of the frequency reference signal from the generator 4 through the first 13 frequency divider and the feedback signal obtained after converting the pulses from the photo-pulse speed sensor 14 The detection of the magnitude of the phase mismatch is carried out by means of a frequency-phase discriminator 3.

In all modes of operation of the electric drive, the rotation of the shaft of the motor 1 and the mechanically associated photo-pulse sensor 14 leads to the appearance of pulse signals located in its quadrature at its first and second outputs [2]. The frequency of their change f ₁₄ is defined as

where: Ω is the angular velocity of the motor shaft 1;

p is the number of marks of the photopulse sensor 14.

The device provides the formation of the output signal for each change in the pulse at the output of the photopulse sensor 14. Since two quadrature sequences of pulses are used, the frequency of the measured signal taken from the triggers 17 and 22 '', f ₁₇ is defined as:

In this case, a strict correspondence is maintained between the direction of rotation of the motor shaft 1 and the signal value at the output 14.2 at the time of the appearance of the pulse at the output 14.1 of the photo-pulse speed sensor 14. To determine the direction of rotation of the motor shaft, trigger 10 is used.

Figure 2 presents a graphotopological diagram of the operation of the interference suppression unit.

The frequency of the signal at the output of the third 7 frequency divider t ₇ is defined as

where f ₄ is the frequency of the generator 4,

N ₇ - conversion factor of the third divider 27.

The frequency f _{13 of the} output signal of the trigger 13 will be half the value of f ₇ .

The function of the multiplexer 9, that is, its output signal D ₁₄ , is determined, according to [5], as

where U ₁₄ is the signal at the control input of multiplexer 14,

(DI ₁ -DI ₄ ) - signals at the first to fourth information inputs of the multiplexer 14, respectively,

A ₁ , A ₂ - signals at the first and second address inputs of multiplexer 14, respectively.

Since in this mode a logical zero is present at the first address input of the multiplexer 14, its output signal is determined by the signal levels at the second or fourth information inputs, depending on the direction of rotation of the motor shaft 1. Since these pulses receive frequency pulses f ₁₃ , then, according to (4), pulses of the same frequency appear at the output of the multiplexer. The relative duration of these pulses is 0.75. The pulse repetition rate at the output of the second frequency divider 6 is defined as:

where N ₆ is the conversion factor of the divider 6.

Therefore, even in the absence of rotation of the shaft of the engine 1, the frequency-phase discriminator is switched at a frequency f ₆ . This provides small losses in the engine 1 when it is running at low angular speeds.

Consider the case of rotation of the motor shaft clockwise. When the signal changes at the first 8.1 output of the photopulse speed sensor 8, for example, when it changes from a logical zero to a logical unit, (Fig. 3), the first front of the signal of the generator 4 of the driving frequency changes the state of the trigger 16. In this case, the output of the first 18 "EXCLUSIVE OR" a logical unit signal appears. This leads to the appearance of a logical zero at the outputs of the element 25 "OR NOT" and element 26 "OR". The decline of this signal causes the switching of the trigger 15, after which at its output, and therefore the third input of the element 28 "OR", a logical unit is set. This signal prohibits the passage of pulses from the generator 4 of the driving frequency to the counting inputs of the triggers 16 and 19. In this case, the signal at the output of the multiplexer 27 corresponds to the direction of rotation of the motor shaft 1. The next pulse of the generator 4 of the driving frequency causes the trigger 17 to switch to the state of a logical unit. Therefore, the signals at the inputs of the element EXCLUSIVE OR 18 become the same, and a logic zero signal appears at its output. This leads to the restoration of the logical unit of signals at the outputs of the elements 25 "OR-NOT" and 26 "OR". When the signal drops at the output of the OR element 26, the output of the trigger 10 sets a signal equal to the output signal of the multiplexer 27, that is, corresponding to the direction of rotation of the motor shaft 1. At the output of the trigger 11, a signal of a logical unit is set. The first edge of the signal from the trigger 13 sets the output of the trigger 12 signal of a logical unit. This leads to a reset of the output signal of the triggers 10 and 15. The signal of the logical unit at the output of the trigger 12 prohibits the passage of pulses through the multiplexer 14 when the signal of the logical unit at the output of the trigger 10. Since the reset of the trigger 12 occurs on the next edge of the pulse of the trigger 13, only the carving two pulses from a sequence with a frequency of f7. The duration of the signal at the output of the trigger 12 t ₁₂ is defined as

When the trigger 12 output signal is set, the logical unit signal is present at the first input of the OR element 28, which prohibits the pulses of the reference frequency generator 4 from passing to the counting inputs of triggers 16 and 19. The number of pulses in the sequence with frequency f ₁₄ decreases by one. After removing the signal from the output of the trigger 12, the passage of pulses through the element 26 "OR" is allowed to the counting inputs of the triggers 16 and 19. The device goes into standby mode for receiving the next edge of the signal of the photopulse speed sensor 8.

While maintaining the direction of rotation, the next moment of reading the signal from the photopulse sensor 8 occurs when a signal appears on its second output. In this case, the output of the trigger 19 is set to a logical unit, which leads to a mismatch of the signals at the inputs of the elements 22 and 23 "EXCLUSIVE OR", and therefore to the appearance of a logical unit at the outputs of these elements. The signals from the outputs of element 23 and trigger 19 change the value of the address of multiplexer 27. Therefore, another information input is connected to its output, the value of the signal at the input of which is determined by the direction of rotation. When the motor shaft rotates clockwise, a logic unit signal is transmitted to the multiplexer output. The signal from the output of element 22 leads to the appearance of a logical unit at the outputs of elements 25 "OR-NOT" and 26 "OR". This sets the signal at the output of the trigger 15, which prohibits the passage of pulses from the generator 4 of the driving frequency to the counting inputs of the triggers 16 and 19. The next pulse of the generator 4 of the driving frequency sets the logic unit at the output of the trigger 20. This equalizes the signals at the inputs of the element 22 "EXCLUSIVE OR " Therefore, a logic zero signal is set at its output, which leads to the loss of signals at the outputs of elements 4 "AND" and 26 "OR". The decline in the output signal of the element 26 "OR" leads to the installation at the output of the trigger 10 of the signal equal to the output signal of the multiplexer 27 and the appearance of a logical unit at the output of the trigger 11. The next pulse of the generator of the driving frequency sets the logical unit at the output of the trigger 21, which leads to the appearance of a logical zero the output of element 23 is EXCLUSIVE OR. In this case, the output signal of the multiplexer 27 may change. This does not affect the operation of the device, since the signal of the direction of rotation of the motor shaft 1 is already fixed by trigger 10.

The nearest edge of the pulse from the trigger 13 leads to the appearance of a logical unit at the output of the trigger 12. This signal resets the trigger 15 and during its presence prohibits the switching of the triggers 16 and 19. The logical unit at the output of the trigger 12 is stored for a period of time t ₁₂ defined by the expression (6). During this time, two pulses are cut from the output of the frequency divider 7. The number of pulses in a sequence with a frequency of f ₁₄ decreases by one. After removing the signal from the output of the trigger 12, the passage of pulses through the element 26 "OR" is allowed to the counting inputs of the triggers 16 and 19. The device goes into standby mode for receiving the next edge of the signal of the photopulse speed sensor 8.

When changing the direction of rotation of the shaft of the engine 1 (Fig 4), the elements forming a sequence of pulses from the output of the element 26 "OR", work similarly to the above. In this case, only the value of the output signal of the multiplexer changes when the signal from the output of the OR element 26 drops due to a change in the address signals at its inputs. Accordingly, the signal recorded in the trigger 10 also changes. Therefore, during the action of the pulse from the output of the trigger 12 t _{12 it is} allowed to pass through the multiplexer 14 pulses from the output of the frequency divider 7. Moreover, each change in the signals at the outputs of the photopulse speed sensor 8 leads to the appearance of an additional pulse in sequence with a frequency f ₁₄ .

Thus, it is obvious that when the motor shaft is rotated through an angle Δφ equal to a quarter of the distance between the marks of the photopulse speed sensor 8, one pulse is added or excised in the sequence with frequency f ₁₄ . Wherein

The total number of pulses at the output of the multiplexer 14 in the period of time between pulses from the output of the element 26 "OR" t ₂₆ , is defined as

where T ₁₃ = f ₂₃ ^-1 is the period of the frequency of the output signal of the trigger 13.

The average frequency of the output signal of the multiplexer 14 can be found on the basis of (8), taking into account (2) in the following expression:

The current position t ₁₄ [j] of the pulses of frequency f ₁₄ can be defined as

where N ₈ is the number of pulses from the sensor 8, which came during the considered period of time T.

Obviously, the value of t ₁₄ [j] is uniquely determined by the number of pulses received from the sensor 8, that is, the angle of rotation of the motor shaft 1. The average value of the frequency taken from the divider 6

where p ^* = 4p / N ₆ is the equivalent number of speed meter marks.

Thus, the mutual correspondence between the angular velocity of the shaft of the engine 1 and the frequency of the signal at the output of the frequency divider 6 is maintained. This mutual correspondence is maintained between the position of the shaft of the motor 1 and the pulses at the output of the frequency divider 6.

The inputs of the frequency-phase discriminator 3 receive the reference frequency pulses from the divider 9 - f ₉ and feedback from the converter 2 of the signal of the photopulse speed sensor 8 - f ₈ . In the stabilization mode of the engine 1 speed, when the frequencies of the reference and feedback signals are approximately equal, the pulse duration at the first or second outputs of the frequency-phase discriminator 3 is determined by the phase difference of these signals. If f ₉ > f ₆ , the pulse-width signal appears at the first output of the frequency-phase discriminator 3 connected to the modulating input of the power converter 5. In this case, the signal at its second output remains constant. When f ₉ <f _{6, the} pulse-width signal appears at the second output of the frequency-phase discriminator 3 connected to the reversing input of the power converter 5. In this case, the signal at its first output remains constant. With a significant difference in the input frequencies, the frequency-phase discriminator 3 switches to the mode of frequency comparison of signals, characterized by the following relationships:

where γ _3.1 and γ _3.2 are the relative durations of the pulse-width signals at the first and second outputs of the frequency-phase discriminator 3, respectively.

The deviation of the output frequency of the divider 6 compared with the frequency f9 at the first input of the frequency-phase discriminator 3 changes the mutual phase position of the pulses of these signals. In this case, the pulse width of the pulse-width signal changes at its second output at ΔT [i]. The magnitude of this increment ΔT [i] is found from the following considerations. The phase mismatch t [i] of the pulses of the frequency-phase discriminator 3 in the considered interval is defined as

where t [i-1] is the magnitude of the phase mismatch of the control pulses of the frequency-phase discriminator 3 on the (i-1) interval

T ₉ - the period of the signal at the output of the frequency divider 9.

Therefore, the increment ΔT [i] for one period of the output signal of the divider 6 t [i-1] can be found as

Since in the quasi-steady mode, the frequency period at the first input of the frequency-phase discriminator 3 is constant and T ₉ = T ₆ , we can assume that ΔT [i] is determined only by changing the frequency period of the second divider. During one period of the output signal of the frequency divider 9, the position of the pulse from the frequency divider 6 is determined using expression (10) as

In the General case, for the period of frequency f ₆ comes several pulses of the sensor 8, the number of which N ₈ is defined as

- угол поворота вала двигателя 1 за рассматриваемый промежуток времени.Where

- the angle of rotation of the shaft of the engine 1 for the considered period of time.

Taking into account (15) and (16), the increment in the duration of the output signal of the frequency-phase discriminator is defined as

The delay in changing the position of the pulse of the divider 6 depends on the state of this divider at the time of the pulse formation from the speed sensor 8. Obviously, it cannot exceed the duration of the output signal of the frequency divider 6.

The error in determining the position of the pulse of the divider 6 occurs due to the discreteness of its formation. Its value is determined by the difference in the period of this frequency and its ideal value. The difference of these quantities is found from the following expression

where k is the integer number of pulses of the sensor 8 during the time T ₂₆ .

The value δT, referred to the period of the ideal value of the converted frequency of the photopulse sensor corresponding to a certain value of the angle of rotation of the motor shaft 1, is the relative error δφ of the conversion of its current position, which is found by the expression of the form

The maximum value of δφ does not exceed N ₆ ^-1 . When N ₆ > 1000, the error in measuring the position of the shaft of the engine 1 is not more than 0.02%.

Thus, when working at relatively high speeds of rotation of the shaft of the engine 1, it is possible to measure the position of the shaft of the engine and its speed with minimal errors. With an increase in the resolution of the photopulse speed sensor 8 and a decrease in the level of operating speeds, the position of the pulses starts to affect the position of the pulses from the sensor output, due to the nature of the output voltage of the power converter 5. This is especially true for synchronous common-mode electric drive systems with a wide range of angular velocity control. In this case, the shaft of the engine 1 pulsates near a certain predetermined position, which leads to the appearance of the fronts of the pulses of the photopulse speed sensor 8, following with a high frequency with almost no movement of the motor shaft 1. If these signals follow with an interval of time greater than T ₁₃ , then the device operates in an operating mode, considering incoming pulses as having a different direction of rotation. If the interval between these fronts becomes smaller than T ₁₃ , then, in principle, it is possible to skip one information front, which leads to distortion of information about the actual position of the motor shaft. To eliminate the loss of information about the actual position of the motor shaft in the proposed device uses a trigger 15 and the element 28 "OR". Timing diagrams of the operation of the device in this mode are shown in Fig.5. In this case, the case is considered when the time interval between the front and the decay of the signal at the first 8.1 output of the photopulse speed sensor 8 is less than T ₁₃ . After the front of the output signal of the photopulse speed sensor 8, the first edge of the pulse of the generator 4 of the reference frequency sets the trigger 16. In this case, the output of the element 18 EXCLUSIVE OR appears a signal of a logical unit, which leads to the reset of the output signal of the element 26 "OR". At this moment, trigger 15 is installed and prohibits the further passage of pulses from the generator 4 of the driving frequency to the counting inputs of the triggers 16 and 19. These triggers store information about the signals at the outputs of the photopulse speed sensor 8 at the time of the appearance of the pulse from the generator 4 of the driving frequency. The next pulse front of this generator sets the trigger 17, which leads to the appearance of a logical unit at the output of the element 26 "OR". The front of this signal sets the trigger 11 and writes to the trigger 10 the signal level corresponding to the direction of rotation of the motor shaft 1. The front of the output signal of the trigger 13 sets the logical unit at the output of the trigger 12, which leads to the reset of the triggers 11 and 15. Despite the reset of the signal from the output of the trigger 15, the passage of signals from the generator 4 of the driving frequency to the counting inputs of the triggers 16, 19 is not allowed, since at the first output the element "OR" 28 is a signal of a logical unit. For the period of the output signal of the trigger 13, the passage of pulses through the multiplexer 14 is prohibited. Therefore, one pulse is cut out from the output sequence with a frequency of f ₁₄ . After resetting the trigger 12, the first pulse from the generator 4 of the driving frequency resets the trigger 16, since there is a logic zero signal at its information input. In this case, at the output of the element “EXCLUSIVE OR” 18, a logical unit arises, which leads to a reset of the output signal of the element “26”. In this case, the trigger 15 is installed and prohibits the passage of pulses from the generator 4 of the driving frequency to the counting inputs of the triggers 16 and 19. The next edge of the pulse from the output of the generator 4 of the driving frequency leads to the reset of the trigger 17 and the appearance of a logical zero at the output of the element 18 "EXCLUSIVE OR". In this case, the logical unit arises at the output of the OR element 26, the appearance of which leads to the installation of the trigger 11 and the inversion of the output signal of the trigger 10. The front of the output signal of the trigger 13 sets the trigger 12 and resets the trigger 11 and 15. During the presence of the signal at the output of the trigger 12 taking into account the output signal of the trigger 10 through the multiplexer 14 to the input of the second frequency divider 6 pass 2 pulses from the output of the frequency divider 7. This corresponds to the addition of one pulse to the sequence of pulse signals with a frequency of f ₁₄ . After resetting the trigger 12, the device is ready to receive the next signal edge from the outputs of the photopulse speed sensor 8. When a similar situation occurs at the second output of the photopulse speed sensor 8, the device works in a similar way.

Thus, even very short pulses from any output of the photopulse speed sensor 8 do not lead to loss of information about the actual position of the motor shaft 1.

In the presence of extended connections between the device and the photopulse speed sensor 8, the appearance of common-mode interference is possible, the effect of which is expressed in the simultaneous appearance of fronts from the output of the measuring transducer. To eliminate this phenomenon, the device uses the elements 24 "AND", 25 "OR NOT" and 26 "OR". The device when the appearance of common mode interference works as follows (figure 5). Let pulses occur at the outputs of the photopulse speed sensor 8, whose fronts are spaced less than the frequency period of the generator 4. Moreover, the signal difference 8.1 of the photopulse speed sensor 8 is useful. A short pulse at output 8.2 represents common mode interference. In this case, the triggers 16 and 19 are switched simultaneously. At the same time, at the outputs of elements 18 and 22, EXCLUSIVE OR, logical units also appear simultaneously. In this case, the output of the element 25 "OR NOT" arises a logical zero. The signals from the outputs of the elements 18 and 22 EXCLUSIVE OR, passing through the element AND 24, cause the appearance of a logical unit at the first output of the element 26 OR. This fact prohibits changing the output signal of the element 26 "OR", and therefore, switching triggers 15 and 11 does not occur. Therefore, the frequency of the output signal of the multiplexer 14 does not change, that is, the false response of the device is eliminated. Subsequently, triggering pulses of trigger 11 are generated due to switching of triggers 19-21, and a signal corresponding to the actual direction of rotation of motor shaft 1 is recorded in trigger 10. A pulse at the output of trigger 12 leads to the cutting out of one pulse from the signal sequence at the output of multiplexer 14.

From the above relationships it follows that the use of the proposed device provides an electronic increase in the resolution of the photopulse speed sensor, at which the relationship between the position of the feedback pulse and the motor shaft 1 is maintained. This allows the proposed drive to be used in phase stabilization systems with higher accuracy characteristics compared with electric drives based on measuring the period of the output signal of the photopulse dates chika [6]. In addition, the proposed drive provides protection against the simultaneous appearance of fronts of the output signals of the photopulse speed sensor without losing useful information about the position of the shaft. Therefore, it is possible to use it in systems based on the use of photopulse speed sensors with a high (more than 100,000 discrete per revolution) resolution and in synchronous-in-phase control systems operating at small deviations of the shaft position from the set value.

The level of angular velocity does not depend on the voltage of the supply network and temperature fluctuations, but is determined only by the instability of the generator 4 of the reference frequency, which when using quartz resonators does not exceed 10 ^-5 %. The electric drive is simple in design and does not contain analog and custom elements.

Information sources

1. Feinstein V.G. Microprocessor control systems for electric drives. - M .: Energoatomizdat, 1986.

2. Circuit design of digital displacement transducers: Reference manual / V. G. Domrachev, V. R. Matveevsky, S. S. Smirnov. - M .: Energoatomizdat, 1987 .-- 392 p.

3. Andrushchuk V.V. Digital systems for measuring the parameters of movement of mechanisms in mechanical engineering. - St. Petersburg: Polytechnic, 1992. - 237 p.

4. RF patent №2161365 class. H2P 5/06. Publ. BI No. 36, 2000.

5. Pukhalsky G.I., Novoseltseva T.Ya. Design of discrete devices on integrated circuits. - M .: Radio and communications, 1990.

6. Trachtenberg P.M. Pulsed astatic electric drive systems with discrete control. - M.: Energoizdat, 1982.

Claims (1)

An electric drive containing a photopulse speed sensor mounted on the shaft of a motor connected to a power converter, the modulating and reversing inputs of which are connected to the first and second outputs of the frequency-phase discriminator, the first input of which is connected through the first frequency divider to the output of the driving frequency generator connected via the third frequency divider and the fourth trigger to the counting input of the third trigger and the first information input of the first multiplexer, the address input of which is connected the reset input of the second trigger and the output of the third trigger, the information input of which is connected to the output of the second trigger, the counting input of which is combined with the counting input of the first trigger, and a second divider is connected between the output of the first multiplexer and the second input of the phase discriminator, characterized in that two EXCLUSIVE OR element, four multiplexers, a fourth divider and six triggers, the counting inputs of which through the fourth divider are connected to the output of the generator of the driving frequency, and the outputs d of the seventh trigger is connected with the counting input of the first trigger, the first input of the first EXCLUSIVE OR element and the first inputs of the second and third multiplexers, the outputs of which are connected to the information inputs of the sixth and seventh triggers, respectively, while the second inputs of the third and second multiplexers are connected to the outputs of the sixth and fifth triggers, the information input of the latter being connected to the second input of the first EXCLUSIVE OR element, the output of which is connected to the control inputs of the second and third meters of multiplexers, and to the first output of the photopulse speed sensor, the second output of which is connected to the second input of the second EXCLUSIVE OR element and to the information input of the eighth trigger, the output of which is connected to the second input of the fourth multiplexer, the output of which is connected to the information input of the ninth trigger, the output of which connected to the second input of the fifth multiplexer, the first input of which is connected to the first input of the fourth multiplexer, the information input of the first trigger, the first input of the second element "AND EXCLUSIVE OR "and the output of the tenth trigger, the information input of which is connected to the output of the fifth multiplexer, the control input of which is connected to the information input of the third multiplexer and the output of the second EXCLUSIVE OR element, while the output of the third divider is connected to the second input of the second divider, and the output of the first trigger is connected to the second information input of the first multiplexer.

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