SU1471064A1 - Instrument for measuring signals of parametric converters - Google Patents

Abstract

The invention relates to the field of measurement technology, in particular, to devices for measuring force using strain gauge dynamometers. The purpose of the invention is to improve the accuracy of measuring the resistances of the strain gauges of the half-bridge force-measuring sensor and the expansion of functionality. Resistances of 56-strain gauge 18.19 half-bridges loaded from the silo-junction machine are measured by selecting conductivities in the respective conductance stores 37,38,39, connected in parallel to the reference resistor 2 and incremental resistors 20,21 of the sensor simulator 43. Conduct stores are controlled using block codes automatics 33 through blocks of registers 34,35,36. The conductivity codes selected during the measurement process through the valve block 40 enter the memory 41. 1 sludge.

Description

one

This invention relates to a measurement technique, in particular, to devices for measuring force using strain gauge dynamometers,

The purpose of the invention is to increase the measurement accuracy of the resistance of the strain gauges of the half-bridge force-measuring sensor and to expand the functionality,

The drawing shows a functional diagram of a device for measuring the signals of parametric transducers — resistances of resistance strain gages — when calibrating a strain-resistor half-bridge force-measuring sensor.

The device contains a power source 1 of the sensor, the circuit of which is pos. The reference resistor 2, the node 3 for compensating the non-informative component of the sensor signal, containing resistor 4 and transformer 5, the primary winding of which is connected parallel to resistor 4, the power source 1 through the communication lines 1, and contacts 6 and 7, 8 and 9 are subsequently included. The Yu switch, 12 and 13 of the switch, containing the switching nodes 14 - 17 of the control, is connected to the strain gauges 18 and 19 of the sensor with additional resistors 20 and 21. The signals from the reference resistor 2 and the connected resistor or strain gauge through the communication lines 1 (, contacts 22 and 23 or 24 and 25 , or 26 and 27, or 28 and 29, and through the secondary windings of the transformer 5 of the compensating unit 3, are fed to the primary windings of the transformers 30 and 31, the secondary windings of which are connected sequentially counter and are connected to the input of the zero-organ 32, the output of the zero-organ 32 connected to the automation unit 33, the output of which is connected to the information inputs of the registers 34-36, and the outputs of these registers are connected respectively to the control inputs of stores 37-39 of conductances connected in parallel to the reference resistor 2 and the additional resistors 20 and 21,

The outputs of registers 35 and 36 are connected to the information inputs of the valve unit 40, the output of which is connected to the input of the memory 41, the control inputs of the registers 34-36, the valve unit 40 and the switching nodes 14-17 are connected to the corresponding outputs of the synchronization unit 42.

Blocks of registers 35 and 36, stores 38 and 39 of conduction and additional resistors 20 and 21 with connections between them are used as a sensor simulator 43 to obtain a calibration characteristic of the sensor complete with geographically distant stationary communication lines and a measuring device by reproducing simulator shoulder resistances equal to the resistances of the strain gauges of the sensor as a function of the magnitude of the effect on the force sensor.

The synchronization node 42 comprises a series-connected clock pulse generator 44, an AND circuit 45, a start trigger 46, a frequency divider 47, a counter 48 and a decoder 49, the outputs of which are output clock pulses for controlling the operation of the device nodes. The generator 44 is also connected to the automation unit 33 and the power source 1 through the AND 45, First, Third, Five and Seventh buses of the decoder 49, respectively, connected to triggers 50 - 53, the outputs of which are connected respectively to the switch control nodes 14-17, The first inputs of the flip-flops 50-53 are connected respectively to the first, fifth, third and seventh tires of the decoder, and the second inputs of the flip-flops 50 - 53 are connected respectively to the third, seventh, fifth and ninth tires of the decoder. The second and the pole of the decoder bus are connected via the OR circuit 54 to the control input of the register 34, respectively, and the fourth and eighth bus of the decoder are connected respectively to the control inputs of the registers 35 and 36. The second, fourth, pole and eighth bus of the decoder via the circuit OR 55 are connected to control input unit 33 automation.

The force applied during the calibration of the measuring half-bridge is performed using a testing machine 56,

The dashed line shows the sensor simulator 43, transferred to the test bench to obtain the sensor calibration characteristic, together with the stationary communication lines 1, and the measuring device 57, the simulator's shoulders, t, e, resistances 20 and 21, with parallel connected stores 38 and 39 conductance, connected via communication lines 1 to the measuring device 57, and the control and information inputs of the registers 35 and 36 are connected to the output of the computer 58, which controls the operation of the stores 38 and 39 in accordance with the stored ayuschee device 41 codes during calibration of the sensor. This aggregate is used to calibrate stationary communication lines and measuring devices in the absence of a testing machine 56 acting on a sensor, on a test stevd where communication lines 1 and measuring device 57 are located,

The device works as follows.

The reference resistor 2 with resistance Wd "Kz, in the power supply circuit of which resistance sensors Ra are alternately connected through the switch contacts, produces a signal taken by the primary

windings of transformers 30 and 31, the secondary windings of which are connected in series to each other, which makes it possible to isolate a signal proportional to & RQ On RJJ. When the transformation ratio is equal to one, the output signal of the secondary windings will be

iuR,

& U iRj - iR

R

S

0

five

0

five

0

five

0

five

i & r signal to digital

where, whether or not, is the informative component of the signal of the strain gauge;

i is the current in the power circuit.

The informative component of the signal of the strain gauge is measured with an analog-to-digital conversion, which is performed by the null organ 32 and the automation unit 33. Node 3 for compensation of the non-informative component of the iRgPo sensor signal doesn’t measure the informative component of ifiRo with a relative error of 1.5-2% (,) for the spread of communication lines from a few to 200 m.

The division factor of divider 47 is chosen so that the time interval between output pulses is not less than the response time of the switch contacts and the conversion time is equivalent, I

After the device elements are set to their initial state (preparation circuits are not shown), using the Start button, a resolution signal is sent from trigger 46 to the arrival of clock pulses from master oscillator 44 through AND circuit 45 to power supply 1, automation unit 33 and through frequency divider 47 a counter 48 and a decoder 49. A series of pulses obtained on the output buses of the decoder 49 is used as device sync pulses.

 the impulse of this sequence arrives at the trigger 50, cocks it, and the signal from its output, sent to the switch control unit 14, connects the strain gauge 18 to the source 1 and the transformer 30 using contacts 6,7, 22 and 23. ibRq sensor. from the secondary windings of transformers 30 and 31 enters the zero-body 32. Through the time interval between the 1st and 2nd

51A

pulses from the output of the frequency divider 47, which is necessary for triggering the contacts of the switch, the pulse of the second decoder bus through the OR circuit 54 allows reading information from the output of the automation unit 33 to the register 34, which controls the conductance magazine 37, and prepares and starts the unit 33 automatics.

The device uses the bit-balancing method, in which the store of 37 conductances parallel to resistor 2 is connected with the clock frequency, parallel to the resistor 2, depending on the ratio of the amplitude of the signals fed to transformers 30 and 31 from the tensor resistor 18 and the resistor 2, bypassed corresponding to the conductivity of the store 37, on each measurement cycle, the null organ 32 supplies the control signal to the automation unit 33, and through it to the register 34, which leaves soprrtivlenie conductivities store 37 connected across the resistor 2, or disables it from resistor 2, thereby balancing resistance 18 and strain gage resistors 2, Since the compound gage 18

is carried out through the communication lines 1, which distort the measurement result, then the resistance of the resistor 2, shunted by the corresponding conductivity set of the store 37, becomes equal to the total resistance of the strain gauge 18 and the communication lines 1 (equivalent resistance of the strain gauge 18).

The third clock pulse received by the decoder 49 removes the disconnected clock pulse turns off the register 35 and outputs a signal to the next 25, five, fifth bus, which translates the trigger 52. To its original state, disconnecting the resistor 20 and the store 38 from the power source 1 and transformer 30. In addition, it cocks the trigger 51, which, through the control unit 15, connects the strain gauge 19 via communication line 1 to the power source 1 and the transformer 30 via contacts 8.

The sixth clock pulse taken from the sixth bus of the decoder 49, through the circuit OR 54, allows reading information from the information block 33 into the register 34, which controls the magazine 37. In addition, it prepares and starts the automation block 33 through the circuit 55 55 in a way. At the end of Eq. 35

40

to read information from the blocking resistance of resistor 2

33 automatics in the register 34 and outputs a signal to the third bus decoder-. the torus 49 flinging the trigger 50 to the initial state, i.e. disconnecting the strain gauge 18 from the power source 1 and from the transformer 30. In addition, it cocks the trigger 52, from the output of which the control signal goes to the node 16, and using a contact 10,11,26 and 27 connects the resistor 20 to the power source 1 and the transformer 30 through the same communication lines 1, with which the strain gauge 18 is connected to these units.

50

55

equal to the equivalent resistance of the strain gauge 19.

The seventh sync pulse turns off the register, flips trigger 51 to its initial state, and also triggers trigger 53, which via the contact control unit 17 12, 13, 28 and 29 connects the resistor 21 and the conduction shop 39 connected in parallel to the power source 1 and to the primary winding of the transformer 30 through the communication lines 1.

The eighth clock pulse through the circuit OR 55 prepares and includes

five

0

The fourth clock pulse, removed from the fourth bus of the decoder 49, prepares and starts the automation unit 33 through the circuit OR 55 and allows the information to be sent to the register 35, which controls the connection of the resistivity store 38 parallel to the resistor 20. Similarly, the resistance of the resistor 2 balanced by the corresponding set is connected store conductivities of .37 and equal to the equivalent resistance of the strain gauge 18, with the resistance of the resistor 20 by means of the bottom of the shunting resistor 20 resistances store 38 conductivities. At the end of the balancing, the equivalent resistance of the resistor 20 is equal to the equivalent resistance of the strain gauge 18.

Fifth sync pulse turns off register 35 and issues a signal to the next 5th, fifth, bus, which translates trigger 52. to its original state, disconnecting resistor 20 and magazine 38 from power supply 1 and transformer 30. In addition, it triggers a trigger 51, which, through the control unit 15, via contacts 8, 9, 24 and 25, connects the strain gauge 19 through the communication lines 1 to the power source 1 and the transformer 30.

The sixth clock pulse taken from the sixth bus of the decoder 49, through the circuit OR 54, allows reading information from the information block 33 into the register 34, which controls the magazine 37. In addition, it prepares and starts the automation block 33 through the circuit 55 55 in a way. At the end of the equation0

35

40

0

five

equal to the equivalent resistance of the strain gauge 19.

The seventh sync pulse turns off the register, flips trigger 51 to its initial state, and also triggers trigger 53, which by means of contact control unit 17 12, 13, 28 and 29 connects resistor 21 and conductivity store 39 connected to it in parallel to power source 1 and to the primary winding of the transformer 30 through the communication lines 1.

The eighth clock pulse through the circuit OR 55 prepares and includes

the automation unit 33 and permits the reading of information in the register 36, which controls the conduction store 39. A balancing of the resistances is performed, at the end of which the resistance of the resistor 21 shunted by the appropriate set of conductances of the magazine 39 is equal to the equivalent resistance of the strain gauge 19.

The ninth sync pulse triggers the trigger 53 to its original state by disconnecting the resistor 2 and the conductance store 39 from the power source 1, and also allows the rewriting of the selected conductance codes from the registers 35 and 36 through the valve block to the memory 41.

Block 43 is then used as a sensor simulator for reproducing the resistances of tensors 18 and 19 when calibrating the sensor with geographically distant stationary communication lines and the measuring device. To do this, the simulator is transferred to a test bench, where the power circuits and measuring circuits of resistors 20 and 21 with connected conductance stores 35 and 36 are connected via fixed communication lines 1 to measuring device 57, and the control for corresponding conductance of stores 38 and 39 from the registers 35 and 36 are fed from the output of the computer 58, where the results of measurements of the resistances of the resistance strain gages 18 and 19 are read from the memory 41, recorded in digital form during the action of the sensor on forces from the test meter Aschiny 56.

Claims (1)

The invention is a device for measuring signals of parametric converters. containing a switch, a power supply of the converter, two transformers with series-inversely connected secondary windings connected to the input of a zero-organ, serially connected to the power supply of the converter, a non-informative component compensation unit JO signal converter and reference a resistor connected to the primary winding of the first transformer, an automation unit whose input is connected to a zero-organ output, and a synchronization node, characterized in that, in order to improve measurement accuracy and enhance functionality, the device is additionally equipped with a memory 20 device, two resistors connected in half-bridge, three control registers, three control conductivity stores and a valve block, each additional resistor through the switch contacts connected to the power supply circuit of the converter with the primary winding of the second transformer, each conductivity store is connected respectively parallel to the reference and two additional resistors, the information inputs of the registers are interconnected and with the output of the automation unit controlling the inputs of the registers of the connection Ina with the outputs of the synchronization unit, and the outputs of the registers are connected to the control inputs of the conductivity stores, the outputs of the second and third control registers of the connection are 40 to the information inputs of the valve unit, the control input and outputs of which are connected respectively to the output of the synchronization unit and memory inputs, which in turn has customer connection terminals. 35