RU2405160C1 - Acceleration measurement device - Google Patents

Abstract

FIELD: physics. ^ SUBSTANCE: acceleration measurement device has a local positive feedback which includes an aperiodic link, a local negative feedback which includes a second order broadband filter and an integrating negative feedback. ^ EFFECT: stability of the device and wider bandpass, while the integrating negative feedback covering the entire device increases accuracy owing to first order astatism and owing to formation of a pulsed connection in the return circuit. ^ 4 dwg

Description

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

A device for measuring accelerations is known (AS No. 1795374 A1, class G01P 15/13, 15/08, 1993), comprising a sensor, a position sensor, an amplifier, a magnetoelectric power converter, the compensation coil of which is connected to the output of the amplifier moreover, a circuit of series-connected first and second resistors is connected to the compensation coil, and the first resistor is shunted by a capacitor.

The disadvantage of such a compensation accelerometer is the dynamic error due to the inclusion of a capacitor in parallel to one of the resistors, which is equivalent to the introduction of an aperiodic link into the accelerometer.

The closest in technical solution is a device for measuring accelerations (RF patent No. 21565625, IPC ⁶ G01P 15/13, bull. No. 11, 04/20/2001), containing a sensing element, an angle sensor, an amplifier and a torque sensor, local positive feedback, introduced from the output of the 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 introduced from the output of the amplifier to the input of the torque sensor through series-connected negative feedback phase detector, high-pass filter, voltage-current converter, negative integrating feedback input from the output of the negative feedback phase detector to the input of the torque sensor, and containing 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, you ode which are inputs to the comparator and the waiting synchronous generators, the second comparator output connected to a second input of the reversible binary counter through a Sleep synchronous generator, said second reversible binary counter output coupled to the second input of the sign selector and the second input of collecting circuit. In addition, the device contains a reference voltage generator, the outputs of which are inputs for an angle sensor, a phase detector of positive and negative feedbacks.

The disadvantage of such a device for measuring accelerations is the low accuracy of the measurement, due to the accuracy of the integrating analog amplifier, the threshold element (comparator) and the limited gain of the open loop, due to the introduction, in the local hard negative feedback, of the link with the transfer function W (s) = K ₁ . In addition, hard negative feedback limits the bandwidth expansion of the accelerometer.

An object of the present invention is to expand the bandwidth of an accelerometer and increase the accuracy of the measurement.

This is achieved due to the fact that in the device for measuring acceleration containing a sensor, an angle sensor, an amplifier, a torque sensor, an integrating amplifier, two voltage-current converters, a phase positive feedback detector, a phase negative feedback detector, negative integrating feedback including a comparator connected in series, a pair of waiting synchronous generators, a reversible binary counter, an additional code to direct converter, an OR collection circuit, binary a multiplier, a smoothing filter and a sign switch, as well as a reference voltage generator and a synchronization circuit, the outputs of which are connected both to the input of the comparator and to the inputs of a pair of standby synchronous generators, the other outputs of the reversible binary counter are connected to the inputs of the OR collection circuit and the sign switch, the output of the angle sensor is connected through the amplifier to the inputs of the phase detectors of positive and negative feedback, the other inputs of which, as well as one of the inputs of the angle sensor are connected to the outputs reference voltage generator, one of the outputs of the phase detector of negative feedback is connected to the input of the integrating amplifier, an aperiodic link is introduced into the positive feedback from the output of the phase detector of positive feedback to the input of the first voltage-current converter, and a broadband filter of the second is introduced into the negative feedback order from the output of the phase detector of negative feedback to the input of the second voltage-current converter, as well as the outputs of the first, second converter Vatel voltage - current and the sign switch are connected to the torque sensor inputs and a binary output of the multiplier is the output of the digital device code.

The introduction of an aperiodic link (delay link), into positive feedback, and a second-order broadband filter, into local negative feedback, allows for device stability and bandwidth expansion, and negative integrating feedback that covers the entire device increases accuracy due to the astatism of the first order. In addition, the introduction of integrating negative feedback into the device, which contains an integrating amplifier, a comparator, a pair of waiting synchronous generators, a reversible binary counter, an additional code to direct converter, a collection circuit, a smoothing filter, and a sign switch allows for self-oscillation mode, the self-oscillation frequency will depend on how from the parameters of the comparator, and from the gain along an open circuit. The formation of a self-oscillating mode can significantly increase the accuracy of measurements and expand the bandwidth

Figure 1 shows a functional diagram of a device for measuring acceleration; figure 2 - simulation scheme of the proposed technical solution; figure 3.4 - discrete output signals in a device for measuring acceleration, with different values of the transmission coefficient at K = 1000 and K = 1, respectively.

The proposed device contains a sensing element 1, the 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 feedback 4 (FDOOS), and the other output is from the input of the phase detector of positive feedback 5 (FDOS) ) Additional inputs of the angle sensor 2, FDOOS 4, FDPOS 5 are connected to the output from the reference voltage generator 6 (GON). The output FDPOS 5 is connected to the input of the aperiodic link 7, with the transfer function

the output of which is connected to the input of the first voltage converter - current 8, and the output of FDOOS 4 is connected to the input of a second-order broadband filter 9, with a transfer function

ζ ₂ > ζ ₁ , the output of which is connected to the input of the second voltage-current converter 10. The output of the FDOOS 4 is also 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 connected to the input of the standby synchronous generator 13, and the other output of the comparator 12 is connected to the input of the standby synchronous generator 14. The outputs of the standby synchronous generators 13 and 14 are connected to the inputs of the reverse binary counter 15, one output of which is connected to the input of the converter of the additional code in line 16, and d the other output of the reversible binary counter 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. The output of the binary multiplier 18, through the smoothing filter 19, is connected to the input of the sign switch 20, the second input of which is connected with one of the outputs of the reversible binary counter 15. The outputs of the synchronization circuit 21 are connected to additional inputs for the comparator 12, and the waiting synchronous generators 13 and 14. The outputs from the voltage-current converters 8, 10 and sign switch La 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, an integrating amplifier, a sign switch, filters, as well as a synchronization circuit are described in the book: P. Horowitz , W. 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 deviates, 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 inputs FDOOS 4 and FDOS 5. With the help of FDOOS 4, FDPOS 5 and GON 6 the phase of deviation of the sensor 1 is highlighted. At the output of FDOOS 4, the signal will always be in antiphase of the deviation of the sensor 1, and at the output of FDOS 5, the phase of the deviation of the sensor 1. The signal from the output of FDPOS 5, in the form of voltage, steps to the input of the aperiodic link 7, and then to the input of the first converter, the voltage is current 8, the output signal of which is supplied in the form of current to the current winding of the torque sensor 22. The signal from the local negative feedback circuit from the output of FDOOS 4 also comes to the input of the torque sensor 22 through a second-order broadband filter 9, to the input of the second converter, the voltage is current 10. The filter 9, included in the local negative feedback, is intended not only to eliminate the compensating effect of the positive feedback communication negative, but also can significantly increase the transmission ratio by open-loop and performs stabilization device for measuring accelerations (Scheme broadband filter implementation is given in the book G.Lem. Analog and digital filters. Calculation and design. M .: Mir, 1982, p. 127-195). 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 the signal extracted from a signal that is stable in frequency and amplitude from the output 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 ogichesky level. The level of the signal from the output 12 depends on the phase of the deviation of the sensitive 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 out signals in the form of a pulse at a frequency of 10 MHz, each the impact 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 the positive information in the direct code, and negative information in the additional code and the conversion of the additional 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 the deviation the sensor 1 in the GON 6 phase, and from the converter of the additional code in line 16, if the phase of the sensor 1 deviation 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 a sign of the sign of the reversible binary counter 15 is received at the current winding of the moment sensor 22. Signals from the outputs 8, 10 and 20 will be received at the current winding 22, and the moment developed by the moment sensor 22 will eliminate the angular deviation of the sensing element caused by acceleration action. The introduction of feedback accelerations to the device provides improved accuracy and increased bandwidth. The output of the binary multiplier 18 is the output of the digital code of the device for measuring accelerations.

The choice of the values of the transfer coefficient over an open circuit and the cutoff frequency can be determined by the methodology described in the patent of the Russian Federation No. 2165625, IPC ⁶ G01P 15/13, bull. No.11, 04/20/2001

The technical effectiveness of the proposed device can be assessed by modeling (figure 2). The simulation results, with open-loop transmission coefficients K = 1000 and K = 1, are shown in figure 3 and figure 4. From the analysis of the results it follows that the frequency of the discrete output signal, which determines the passband, depends on the open-loop transmission coefficient. Introduction to local positive feedback of the lag link with the transfer function

and the local negative feedback of the second-order broadband filter with the transfer function

ζ ₂ > ζ ₁ can significantly increase the open-loop transmission coefficient (without loss of stability), increase the accuracy and expand the device bandwidth due to the implementation of the self-oscillation mode (the self-oscillation frequency can be changed either by changing the width of the comparator's ambiguity zone, or by increasing the transmission coefficient by open loop). In addition, maintaining negative integrating feedback into the device for measuring accelerations allows realizing deviation astatism and obtaining a discrete code proportional to the input signal.

Claims (1)

An acceleration measuring device comprising a sensor, an angle sensor, an amplifier, a torque sensor, an integrating amplifier, two voltage-current converters, a positive feedback phase detector, a negative feedback phase detector, negative integrating feedback, including a comparator connected in series, a pair of waiting synchronous generators, reversible binary counter, additional code to direct converter, OR collection circuit, binary multiplier, smoothing filter p and a sign switch, as well as a reference voltage generator and a synchronization circuit, the outputs of which are connected both to the input of the comparator and to the input of a pair of waiting synchronous generators, the other outputs of the reversible binary counter are connected to the inputs of the OR collection circuit and the sign switch, while the sensor output the angle is connected through the amplifier to the inputs of the phase detectors of positive and negative feedback, the other inputs of which, as well as one of the inputs of the angle sensor, are connected to the outputs of the reference voltage generator I, one of the outputs of the phase detector of negative feedback is connected to the input of the integrating amplifier, characterized in that an aperiodic link is introduced into the positive feedback from the output of the phase detector of positive feedback to the input of the first voltage-current converter, and a broadband filter is introduced into the negative feedback second order from the output of the phase detector of negative feedback to the input of the second voltage-current converter, as well as the outputs of the first, second converter voltage - current and the sign switch are connected to the torque sensor inputs and a binary output of the multiplier is the output of the digital device code.

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