RU2308038C1 - Device for measuring acceleration - Google Patents

Abstract

FIELD: measuring technique.

SUBSTANCE: device comprises sensor, angle pickup, amplifier, moment pickup, and positive and negative integrating feedbacks. The positive feedback connects the output of the amplifier with the input of the moment pickup through phase detector of the positive, first differential unit, adder, voltage-current converter connected in series. The output of the first differential unit is connected with the input of the second differentiating unit whose output is connected with one of the outputs of the adder. The negative integrating feedback connects the output of the amplifier with the input of the moment pickup through the integrating amplifier, comparator, synchronous generator, reverse binary counter converter of the additional code, OR circuit whose output represents the output of the digital code unit, binary multiplier, smoothing filter, and sign switch connected in series. The second output of the comparator is connected with the second input of the reverse binary counter through the second synchronous generator. The device is additionally provided with the synchronizing circuit whose outputs are the inputs of the comparator and synchronous generators and generator of reference voltage whose outputs represent the outputs of the angle pickup, and phase detector of positive and negative feedbacks.

EFFECT: expanded functional capabilities.

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Description

The invention relates to measuring equipment and can be used as an element in stabilization, navigation and guidance systems. It can find application in devices for measuring mechanical values of the compensation type.

A device for measuring accelerations is known (RF patent No. 2098833, IPC ⁶ G01P 15/13, publ. 10.12.97) containing a sensing element including two fixed electrodes and a movable plate, three amplifiers, two resistors, while the output of the first amplifier connected to the first resistor, and the input of the second amplifier is connected to the second resistor and is the output of the device. To increase the noise immunity, under the influence of electrical noise, a reference voltage source, an electric signal generator, two transistor pairs, three resistors, two capacitors are introduced into it, which allow, due to the coverage of the amplifier with negative feedback, to compensate for electrical noise.

The disadvantage of this device is the low accuracy of the measurement, since the choice of gain, with hard negative feedback, is limited by the condition of stability of the system.

The closest in technical solution is the device (US Pat. RU 2165625, IPC ⁷ G01P 15/13, publ. 04/20/2001, bull. No. 11), containing a sensing element, an angle sensor, an amplifier and a torque sensor, local positive feedback from the output amplifier to the input of the torque sensor through a series-connected phase detector of positive feedback and a voltage-current converter. Local negative feedback is introduced from the amplifier output to the moment sensor input through a series-connected negative feedback phase detector, high-pass filter, voltage-current converter. Negative integrating feedback is introduced from the output of the phase detector of negative feedback to the input of the torque sensor and contains a series-connected integrating amplifier, a comparator, a waiting synchronous generator, a reversible binary counter, an additional code to direct converter, a collection circuit (OR), a binary multiplier, a smoothing filter , a sign switch and a synchronization circuit, the outputs of which are inputs for the comparator and waiting synchronous generators. The second output of the comparator is connected to the second input of the reversible binary counter through a standby synchronous generator. The second output of the reversible binary counter is connected to the second input of the sign switch and the second input of the collection circuit, the output of which is the output of the digital code of the device. In addition, the device contains a reference voltage generator, the outputs of which are inputs to an angle sensor, a phase detector of positive and negative feedbacks, and the output of the collection circuit (OR) is the output of the device in the form of a digital code.

The disadvantage of this device is the small bandwidth.

The present invention is to expand the bandwidth of the device and improve the accuracy of the measurement.

This is achieved due to the fact that in the device for measuring acceleration containing a sensing element, an angle sensor, an amplifier, positive feedback from the amplifier output to the input of the torque sensor through a series-connected positive feedback phase detector and a voltage-current converter, negative integrating feedback from the amplifier output to the input of the torque sensor through a series-connected phase negative feedback detector, integrating amplifier, comparator, first standby a synchronous generator, a reversible binary counter, an additional code converter to direct, a collection circuit (OR), a binary multiplier, a smoothing filter, a sign switch, while the second output of the comparator is connected to the second input of the reversible binary counter via a second standby synchronous generator, and the second output of the reverse the binary counter is connected to the second inputs of the collection circuit and the sign switch, and the outputs of the reference voltage generator are connected to the inputs of the angle sensor and phase field detectors of positive and negative feedbacks, and the outputs of the synchronization circuit are connected to the inputs of the comparator and the waiting synchronous generators, the first and second differentiating devices are introduced into positive feedback from the output of the phase feedback detector of positive feedback to the input of the voltage-current converter through an adder, the inputs of which are connected to the outputs the first and second differentiating devices, and the input of the second differentiating device is connected to the output of the first differentiating devices, and the output of the collecting circuit tions (OR) is an output digital code devices.

The introduction of feedback of different signs into the device ensures the stability of the device and the expansion of the passband, and negative integrating feedback increases accuracy due to first-order astatism, as well as due to the formation of pulsed communication in the feedback circuit.

Figure 1 shows a block diagram of a device; figure 2 - transient in the prototype; figure 3 - LAFCH in the prototype; figure 4 - transient in the proposed device; figure 5 - LAFCH in the proposed device.

The proposed device contains a sensing element 1, made in the form of a pendulum, an angle sensor 2, the output of the angle sensor 2 is connected to the amplifier 3. One output of the amplifier 3 is connected to the input of the phase detector of negative integrating feedback 4 (FDOOS), and the other output 3 is connected to the input positive feedback phase detector 5 (FDOS). Additional inputs for the angle sensor 2, FDOOS 4, FDPOS 5 are connected to the output of the reference voltage generator 6 (GON). The output of the PDPOS 5 is connected to the input of the first differentiating device 7, one of the outputs of the first differentiating device 7 is connected to the input of the second differentiating device 8, the outputs 7 and 8 are connected to the inputs of the adder 9, the output of which is connected to the input of the voltage converter - current 10. The output of the PDOS 4 is connected to the input of the integrating amplifier 11, the output of which is connected to the input of the comparator 12. One output of the comparator 12 is the input of the standby synchronous generator 13, and the other output 12 is connected to the input of the standby synchronous generator RA 14. The outputs of the standby synchronous generators 13 and 14 are connected to the inputs of the reversible binary counter 15, one output of which is an input for the converter of the additional code in line 16, and the other output 15 is connected to one of the inputs of the collection circuit (OR) 17. The output of the collection circuit 17 is connected to the input of the binary multiplier 18 and at the same time is the information output of the device. The output of the binary multiplier 18 through the smoothing filter 19 is connected to the input by a sign switch 20, the second input of which is connected to one of the outputs of the reversible binary counter 15. The outputs of the synchronization circuit 21 are additional inputs for the comparator 12 and the standby synchronous generators 13 and 14. The outputs from the voltage converter - current 10 and sign switch 20 are connected to the inputs of the torque sensor 22.

The internal contents of FDOOS, FDPOS, a comparator, waiting synchronous generators, a reversible binary counter, an additional code to direct converter, a collection circuit (OR), a binary multiplier, a sign switch, a synchronization circuit, differentiating devices and an adder are described in the book: P. Horowitz, U . Hill. The art of circuitry. M.: Mir, t.1-3, 1993.

A device for measuring acceleration works as follows.

Under the action of acceleration W on the sensitive element 1, made in the form of a pendulum, the inertial moment equal to mlW acts (l, m is the length and mass of the pendulum). Under the influence of this moment, the sensor 1 is deflected, which is detected by the angle sensor 2, the field windings of which are connected to the output of the GON 6. The signal from the angle sensor 2 after amplification by the amplifier 3 is fed to the outputs FDOOS 4 and FDPOS 5. Using FDPOS 4 and GON 6 the phase of deviation of the sensing element 1 is highlighted. At the output of FDOOS 4, the signal will always be in antiphase of the deviation of the sensitive element 1, and at the output of FDOS 5 - the phase of deviation 1. The signal from the output of FDOS 5 in the form of voltage is fed to the input of the first differential control device 7 (at output 7, the signal in the form of a voltage is proportional to the first derivative of deviation 1), one of the outputs of which is connected to the input of the second differentiating device (second derivative of deviation 1). The outputs 7 and 8, in the form of voltage, go to the inputs of the adder 9, the output of which has a signal in the form of the sum of the signals of the first and second derivatives of the deviation 1. Output 9 goes to the input of the converter voltage - current 10, the output signal of which the form of current flows to the current winding of the torque sensor 22. The torque sensor 22 develops a moment that compensates for the inertial moment caused by the acceleration, and the sensing element 1 returns to its original position. The signal in the form of a voltage with FDOOS 4 is fed to the input of the integrating amplifier 11. The voltage from the output of the integrating amplifier 11 is supplied to one of the inputs of the comparator 12. In the comparator 12, the signal from the output of the amplifier 11 is compared with a signal isolated from a signal that is stable in frequency and amplitude with the output of the synchronization circuit 21. If the signal from the output of the integrating amplifier 11 is more than the triangular voltage from the output 21, then the output of the comparator 12 will be a high logic level, if less, then the output of the comparator 12 will be low ogic level. The signal level depends on the phase of the deviation of the sensing element 1. The signals from the comparator 12, in the form of a level, are fed to the inputs of the waiting synchronous generators 13 and 14, which, using the synchronization circuit 21, give signals in the form of a pulse at a frequency of 10 MHz for each action of the incoming signal ( output 12) equal to "1". The reversible binary counter 15 counts the single pulses from the output of the standby synchronous generator 13, and subtracts the pulses from the output of the standby synchronous generator 14. Reverse binary counter 15 represents positive information in the direct code, and negative information in the additional code, and the conversion of additional the code in direct is carried out by the converter of the additional code in direct 16. At the input of the collection circuit 17 (OR), signals are received from the reverse binary counter 15, if of the sensitive element 1 in the phase EOU 6 and the additional code converter 16 directly, if the phase is 180 °. After the logical addition of the signals at 17, the output signal from 17 is fed to the input of the binary multiplier 18, the output of which will be pulses, the number of which is proportional to the binary code supplied to the input of the collection circuit 17. The binary multiplier 18 converts the binary code to one. The smoothing filter 19, to the input of which pulses are received from the binary multiplier 18, not only eliminates the ripple of the input signal from 18, but also ensures the stable operation of the device covered by feedbacks of different signs. A signal from the sign switch 20 with the sign of the sign of the reversible binary counter 15 is sent to the current winding of the moment sensor 22. Signals from the outputs 10 and 20 will be fed to the current winding 22, which will eliminate the deviation of the sensitive element 1 and provide increased accuracy and increased bandwidth of the device for measuring accelerations. The output of the collection circuit 17 is the output of the digital code of the device for measuring accelerations.

The technical efficiency of the proposed device can be estimated using the simulation results (modeling was carried out with the following parameters T = 0.2 s, ξ = 2.

Figure 2 and figure 3 presents the transient and frequency characteristics in the prototype with a cutoff frequency ω _CP ≤7.52 s ^-1 and a coefficient K ₀₁ KK _OSZ ≤30 s ^-2 ; figure 4 and figure 5 shows the transient and frequency characteristics in the proposed device. From figure 5 it follows that the cutoff frequency ω _CP > 473.68 s ^-1 .

From the simulation results it follows that, compared with the prototype, the frequency increased by 87.5 times, and the passband increased by the same amount and the suppression coefficient increased (Fig. 5). The proposed structure for constructing a device for measuring accelerations, with positive feedback on the first and second derivatives and negative integrating feedback, leads to a positive effect.

Thus, the introduction of feedback of different signs into the device increases accuracy and extends the bandwidth.

Claims (1)

A device for measuring accelerations containing a sensor, an angle sensor, an amplifier, positive feedback from the amplifier output to the input of the torque sensor through a series-connected phase positive feedback detector and a voltage-current converter, negative integrating feedback from the amplifier output to the input of the torque sensor through serially connected phase negative feedback detector, integrating amplifier, comparator, first standby synchronous generator, reversible a binary counter, an additional code converter into a direct one, a collection circuit (OR), a binary multiplier, a smoothing filter, a sign switch, while the second output of the comparator is connected to the second input of the reversible binary counter via a second standby synchronous generator, and the second output of the reversible binary counter is connected to the second inputs of the collection circuit and the sign switch, and the outputs of the reference voltage generator are connected to the inputs of the angle sensor, phase detectors of positive and negative reverse connections, and the outputs of the synchronization circuit are connected to the inputs of the comparator and waiting synchronous generators, characterized in that the first and second differentiating devices are introduced into the positive feedback from the output of the phase feedback detector of positive feedback to the input of the voltage-current converter through an adder, the inputs of which are connected to the outputs the first and second differentiating devices, and the input of the second differentiating device is connected to the output of the first differentiating device, and the output of the collection circuit (OR) is etsya output of the digital device code.

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