SU894371A1

SU894371A1 - Device for measuring mechanical impedance of objects with inherent mobility

Info

Publication number: SU894371A1
Application number: SU792819670A
Authority: SU
Inventors: Павел Васильевич Палкин; Юрий Михайлович Васильев; Владимир Степанович Ванаев; Евгений Сергеевич Петрашкин
Priority date: 1979-09-10
Filing date: 1979-09-10
Publication date: 1981-12-30

Description

Изобретение относится к вибрационной технике и предназначено для измерения механического импеданса биологических объектов.The invention relates to vibration technology and is intended to measure the mechanical impedance of biological objects.

Известно устройство для измерения импеданса, содержащее регистратор модуля, последовательно соединенные акселерометр с интегрирующим предусилителем и последовательно соединенные генератор, усилитель мощности, вибратор, состоящий из корпуса, ¹ электромагнита, жестко закрепленного в нем, подвижной части (вибростола), закрепленной в корпусе с помощью упругого подвеса, и катушки с обмоткой, расположенной между полюсами электромагнита, датчик силы, предусилитель, схему компенсации масс, ко второму входу которой подсоединен акселерометр и последовательно соединенные с генератором фазометр и регистратор фазы, кроме того, содержит двухлучевой осциллограф, один выход которого соединен с выходом интегрирующего предусилителя, второй вход соединен с выходом схемы компенсации масс, а выход соединен с регистратором модуля, и датчик смещения, выход которого соединен с входом тензостанции [4].A device for measuring impedance is known, comprising a module recorder, an accelerometer connected in series with an integrating preamplifier and a generator connected in series, a power amplifier, a vibrator consisting of a housing, ¹ electromagnet rigidly fixed therein, a movable part (vibration table) fixed in the housing using an elastic suspension, and coils with a winding located between the poles of the electromagnet, a force sensor, a preamplifier, a mass compensation circuit, to the second input of which an accelerometer is connected and the phase meter and phase recorder connected to the generator, in addition, contains a two-beam oscilloscope, one output of which is connected to the output of the integrating preamplifier, the second input is connected to the output of the mass compensation circuit, and the output is connected to the module recorder, and a bias sensor, the output of which is connected to the input strain stations [4].

Недостатком известного устройства является низкая точность, обусловленная тем, что усилия, полностью передающиеся исследуемым объектом в процессе измерения на датчик силы, вызваны не только вибровозбуждением, но и усилиями от объекта, которые существуют независимо от вибровозбуждения. В случае измерения входного импеданса руки оператора таким усилием будет неравномерное нажатие на рукоять ку, имитирующую рукоятку инструмента. От действия этой силы на выходе датчика силы возникает сигнал, который уменьшает точность измерения.A disadvantage of the known device is the low accuracy, due to the fact that the forces completely transmitted by the investigated object during the measurement to the force sensor are caused not only by vibration excitation, but also by forces from the object, which exist independently of vibration excitation. In the case of measuring the input impedance of the operator’s hand, such an effort will be an uneven pressing on the handle, which imitates the handle of the tool. From the action of this force, a signal arises at the output of the force sensor, which reduces the accuracy of the measurement.

Цель изобретения - повышение точности измерения.The purpose of the invention is to improve the accuracy of measurement.

Указанная цель достигается тем, что устройство снабжено последова894371 тельно соединенными интегратором и схемой компенсации упругости, выход которой соединен с входами регистратора модуля и фазометра, второй вход с выходом схемы компенсации массы, а вход интегратора ~ С входом интегрирующего предусилителя, и датчик силы расположен между вибростолом и катушкой.This goal is achieved by the fact that the device is equipped with a sequentially connected integrator and an elastic compensation circuit, the output of which is connected to the inputs of the registrar of the module and phase meter, the second input with the output of the mass compensation circuit, and the integrator input ~ With the input of the integrating preamplifier, and the force sensor is located between the vibration table and reel.

Кроме того, схема компенсации упругости выполнена в виде последовательно соединенного инвертора, делителя и сумматора.In addition, the elastic compensation scheme is made in the form of a series-connected inverter, divider and adder.

На фиг. 1 приведена схема устройства для измерения импеданса; на фиг.2 схема блока компенсации упругости.In FIG. 1 shows a diagram of a device for measuring impedance; figure 2 diagram of the block compensation elasticity.

Устройство содержит регистратор 1 модуля, последовательно соединенный акселерометр 2 с интегрирующим предусилителем 3. Устройство также содержит генератор 4, усилитель 5 мощности, вибратор, состоящий из корпуса 6, электромагнита 7, жестко закрепленного в нем, вибростола 8, закрепленного в корпусе 6 с помощью упругого подвеса 9, и катушки 10 с обмоткой 11, расположенной между полюсами электромагнита 7. В состав устройства входят последовательно соединенные датчик 12 силы, расположенный между в^бростолом 8 и катушкой 10, предусилитель 13, схема 14 компенсации масс. Устройство содержит последовательно соединенные с генератором 4 фазометр 15 и регистратор 16 фазы. Устройство также снабжено последовательно соединенными интегратором 17 и схемой 18 компенсации упругости. На вибростоле 8 закреплен переходник 19 с расположенным на нем объектом 20 измерения. Схема компенсации упругости выполнена в виде последовательно соединенных инвертора 21, делителя 22 и сумматора 23.The device comprises a module recorder 1, a series-connected accelerometer 2 with an integrating preamplifier 3. The device also contains a generator 4, a power amplifier 5, a vibrator consisting of a housing 6, an electromagnet 7, rigidly fixed therein, a vibrating table 8 fixed in the housing 6 with an elastic a suspension 9, and a coil 10 with a winding 11 located between the poles of the electromagnet 7. The structure of the device includes a series-connected force sensor 12 located between the beam 8 and the coil 10, preamplifier 13, circuit 14 of the computer nation mass. The device contains a phase meter 15 connected in series with the generator 4 and a phase recorder 16. The device is also equipped with a series-connected integrator 17 and an elastic compensation circuit 18. An adapter 19 is mounted on the vibrating table 8 with a measurement object 20 located on it. The elasticity compensation circuit is made in the form of a series-connected inverter 21, a divider 22, and an adder 23.

Устройство работает следующим образом.The device operates as follows.

Генератор 4 через усилитель 5 мощности возбуждает вибростол 8 на требуемой частоте. Расположенный на вибростоле 8 переходник 19 передает виброусилие на измеряемый объект 20, Сигнал с датчика 12 силы и акселерометра 2 поступает в предусилители 3 и 13. На выходе интегрирующего предусилителя 3 с интегрированием образуется сигнал вибросилы, используемый на входе фазометра 15 и для управления генератором 4 с целью поддержания постоянного уровня виброскорости переходника 19, а также для получения путем его интегрирования на интеграторе 17 сигнала виб5 росмещения вибростола 8. Датчик 12 помимо силы, вызванной взаимодействием измеряемого объекта 20 и переходника 19, измеряет силу, необходимую для приведения в движение всех Ю движущихся масс, состоящих из переходника 19, акселерометра 2, вибростола 8, катушки 10, обмотки 11 и датчика 12, а также силу прогиба упругой подвески 9. Эти дополнитель15 ные составляющие исключены из общего сигнала для получения сигнала, соответствующего взаимодействию переходника 19 и измеряемого объекта 20. Схема 14 компенсации масс вычитает 20 из сигнала датчика 12 силы ту часть, которая вызвана приведением в движение движущихся масс. Схема 18 компенсации упругости вычитает из сигнала датчика 12 силу от прогиба упругого 25 подвеса 9, которая пропорциональна величине смещения вибростола 8.Схема 18 компенсации упругости состоит из инвертора 21, делителя 22 и сумматора 23. На вход инвертора 21 посту30 пает сигнал вибросмещения^ с интегратора 17 и инвертируется, а затем делится делителем 22. При помощи сумматора 23 из сигнала датчика 12 силы вычитается сигнал, пропорциональный ₃₅ силе, прогибающей упругий подвес 9· После вычитания составляющих от движения масс и прогиба упругости подвеса с использованием соответственно схемы 14 компенсации масс и 40 схемы 18 компенсации упругости из сигнала датчика 12 силы получаем сигнал, пропорциональный силе взаимодействия руки и переходника, который используется для получения сиг45 нала фазы на фазометре 15 с этого сигнала на регистраторе 16 фазы и для записи его уровня на регистраторе 1 уровня.The generator 4 through the power amplifier 5 excites the vibration table 8 at the desired frequency. The adapter 19 located on the vibrating table 8 transmits the vibration force to the measured object 20, The signal from the force sensor 12 and the accelerometer 2 is fed to the preamplifiers 3 and 13. At the output of the integrating preamplifier 3 with integration, a vibrational signal is generated, which is used at the input of the phase meter 15 and for controlling the generator 4 s the purpose of maintaining a constant level of vibration velocity of the adapter 19, as well as to obtain, by integrating it on the integrator 17, the signal vib5 of the displacement of the vibration table 8. The sensor 12 in addition to the force caused by the interaction of the measured about the object 20 and the adapter 19, measures the force necessary to drive all the Yu moving masses, consisting of an adapter 19, an accelerometer 2, a vibrating table 8, a coil 10, a winding 11 and a sensor 12, as well as the deflection force of the elastic suspension 9. These additional 15 The components are excluded from the general signal to obtain a signal corresponding to the interaction of the adapter 19 and the measured object 20. The mass compensation circuit 14 subtracts 20 from the signal of the force sensor 12 that part that is caused by the moving masses moving. The elasticity compensation circuit 18 subtracts from the signal of the sensor 12 the force from the deflection of the elastic 25 of the suspension 9, which is proportional to the displacement of the vibration table 8. The elasticity compensation circuit 18 consists of an inverter 21, a divider 22, and an adder 23. A vibration offset signal ^ is received from the integrator to the input of the inverter 21 17 and is inverted, and then divided by a divider 22. Using an adder 23, a signal proportional to ₃₅ force deflecting the elastic suspension 9 is subtracted from the signal of the force sensor 12. After subtracting the components from the movement of masses and the deflection of the suspension elasticity using, respectively, the mass compensation circuit 14 and 40 the elastic compensation circuit 18 from the signal from the force sensor 12, we obtain a signal proportional to the force of the interaction of the hand and the adapter, which is used to obtain the phase signal on the phase meter 15 from this signal on the phase recorder 16 and to record its level on the level 1 recorder.

Использование предлагаемого уст₅₀ ройства позволяет повысить точность измерения импеданса биологических объектов за счет снижения влияния изменяющихся характеристик измеряемого объекта на импеданс объекта.Using the proposed device ₅₀ allows to increase the accuracy of measuring the impedance of biological objects by reducing the impact of the changing characteristics of the measured object on the impedance of the object.

Claims

(5) A DEVICE FOR MEASURING THE MECHANICAL IMPEDANCE OF OBJECTS HAVING OWN. The invention relates to a vibration technique and is intended to measure the mechanical impedance of biological objects. A device for measuring impedance is contained, comprising a module recorder, an accelerometer connected in series with an integrating preamplifier and a generator connected in series, a power amplifier, a vibrator consisting of a housing, an electromagnet fixed in it, a moving part (vibrator) fixed in the housing gogo suspension, and a coil with a winding located between the poles of an electromagnet, a force sensor, a preamplifier, a mass compensation circuit, to the second input of which is an accelerometer and p subsequently, a phase meter and a phase recorder connected to the generator also contain a dual-beam oscilloscope, one output of which is connected to the output of the integrating MOBILE preamplifier, the second input is connected to the output of the mass compensation circuit, and the output is connected to the registrar module, and the displacement sensor, the output of which is connected with the entrance of the strain station r. A disadvantage of the known device is low accuracy, due to the fact that the forces that are completely transmitted by the object under study to the force sensor are not only caused by vibration, but also by forces from the object, which exist independently of vibration. In the case of measuring the input impedance of the operator's hand, such an effort will be an uneven pressing of the handle imitating the handle of the tool. From the effect of this force, a signal is generated at the output of the force sensor, which reduces the measurement accuracy. The purpose of the invention is to improve the measurement accuracy. This goal is achieved by the fact that the device is equipped with a sequentially connected integrator and an elastic compensation circuit, the output of which is connected to the module registrar and phase meter recorder inputs, the second input to the mass compensation circuit output, and the integrator input to the integrator preamp input, and a force sensor is located between the vibrating table and coil. In addition, the elastic compensation circuit is made in the form of a series-connected inverter, divider, and adder. FIG. 1 shows a device for measuring impedance; Fig.2 diagram of the block compensation of elasticity. The device contains a recorder 1 module, a serially connected accelerometer 2 with an integrating preamplifier 3. The device also contains a generator H, a power amplifier 5, a vibrator consisting of the body 6 of the electromagnet 7 fixed in it, a vibrating table 8 fixed in the case 6 using an elastic suspension 9, and a coil 10 with a winding 11 located between the poles of the electromagnet 7. The device is connected in series with a force sensor 12 located between the bridge 8 and the coil 10, a preamplifier 13, a circuit com ensatsii wt. The device contains a phase meter 15 connected in series with the generator and a phase recorder 16. The device is also equipped with serially connected by the integrator 17 and the elastic compensation circuit 18. An adapter 19 with a measurement object 20 located on it is fixed on the vibrating table 8. The elastic compensation circuit is made in the form of a series-connected inverter 21, a divider 22 and an adder 23. The device operates as follows. The generator k through the power amplifier 5 excites the vibrating table 8 at the required frequency. The adapter 19 located on the vibrating table 8 transmits the vibration power to the measured object 20. The signal from the force sensor 12 and accelerometer 2 enters preamplifiers 3 and 13. At the output of integrating preamplifier 3 with integration, a signal of the vibrating force is used, which is used at the input of the phase meter 15 and to control the generator k with goal 1. 4 maintaining a constant level of vibration velocity of the adapter 19, as well as for obtaining, by integrating it on the integrator 17, a vibration table of the vibrating table 8. Sensor 12, in addition to the force caused by the interaction of the measured object 20 and adapter 19, measures the force required to set in motion all moving masses consisting of an adapter 19, an accelerometer 2, a vibrating table 8, a coil 10, a winding 11 and a sensor 12, as well as the deflection force of the elastic suspension 9. These additional components are excluded from the common signal to receive the signal corresponding to the interaction of the adapter 19 and the measured object 20. The mass compensation 1C circuit subtracts from the signal of the force sensor 12 that part which is caused by the movement of the moving masses. The elastic compensation circuit 18 subtracts from the sensor signal 12 a force from the deflection of the elastic suspension 9, which is proportional to the displacement of the vibrating table 8, the elastic compensation circuit 18 consists of an inverter 21, a divider 22 and an adder 23. To the input of the inverter 21, a vibration offset signal from the integrator 17 is received and inverted ,, and then divided by divider 22. With the help of adder 23, the signal proportional to the force bending the elastic suspension 9 is subtracted from the signal of the force sensor 12. After subtracting the components from the movement of the masses and the deflection of the elasticity of the suspension Using respectively the mass compensation circuit 1 and the elastic compensation circuit 18, the signal from the force sensor 12 produces a signal proportional to the force of the hand and adapter, which is used to obtain the phase signal and the phase meter 15 from this signal on the 16 phase recorder and to record its level on the recorder 1 level The use of the proposed device makes it possible to increase the accuracy of imbalance of biological objects by reducing the effect of changing characteristics of the measured object on the object impedance. Claim 1. Device for measuring the mechanical impedance of objects having their own mobility, containing a module recorder, a generator connected in series, a power amplifier, a vibrator consisting of a case, an electromagnet rigidly fixed in it, a vibrating table fixed in the case with an elastic suspension , and a coil with a winding located by means of an elastic suspension, and a coil with a winding located between the poles of an electromagnet, a force sensor, a preamplifier, a mass compensation circuit, to the second To the input of which an accelerometer is connected, and a phase meter and a phase recorder connected in series with the generator, it is different in that it is equipped with sequentially connected integrators to improve the measurement

1 and an elastic compensation circuit, the output of which is connected to the inputs of the registrar of the module and the phase meter, the second input of the integrator is with the output of the mass compensation circuit, and the input of the integrator is with the output of the integrating preamplifier, and the force sensor is located between the vibrating table and the coil.

2. A device according to n.t, characterized in that the elastic compensation circuit is made in the form of successively connected inverter, divider and adder. Sources of information taken into account in the examination - 1. Scientific works of the institutes of labor protection 8CSPS, Collection. M., Profizdat, 1976, no. lot, s. 52-58, {rp type).