CN213397179U - Current type vibration temperature sensor and multi-parameter interface module thereof - Google Patents

Abstract

The utility model discloses a current type vibration temperature sensor and many parameter interface module thereof, including ICP sensor, constant current constant voltage source, signal separation circuit, subtracter circuit, full wave rectifier circuit, envelope demodulation circuit, low pass filter circuit and 2 primary integral circuits, many parameter signal extraction circuit via the signal connection subassembly that connector JK1, shielding twisted pair, connector JK2 constitute with to installing the ICP sensor on by the object being monitored and being connected; the beneficial effects are as follows: the sensor adopts a measuring line system constant current source working mode, the signal extraction circuit adopts a constant voltage source working mode, 5 parameters such as vibration acceleration, vibration speed, vibration displacement, impact, temperature and the like in the operation of the monitored object can be extracted, the problem that the installation space of the monitored object is limited in the monitoring of the operation state of the electromechanical equipment is solved, the complex electromagnetic interference under the operation condition of the electromechanical equipment is effectively inhibited, and the structure of the monitoring system is further optimized to improve the stability and the reliability.

Description

Current type vibration temperature sensor and multi-parameter interface module thereof

Technical Field

The utility model relates to a sensor and detection circuitry of mainframe electrical equipment running state monitoring especially relate to an electric current type vibration temperature sensor and many parameter interface module thereof.

Background

The sensor technology is one of three major foundations of information technology and is a high technology which is competitively developed in all developed countries at present. The sensor is similar to a sense organ which is necessary to be used by human beings for acquiring external information, is a detection device, can sense measured information, can convert the sensed information into an electric signal or other information in a required form according to a certain rule and output the electric signal or other information, meets the requirements of information transmission, processing, storage, display, recording, control and the like, and is the first link for realizing automatic detection and automatic control. Generally, one sensor can only measure one physical quantity, and in order to accurately and comprehensively recognize an object and an environment for further monitoring or control, a plurality of sensors are often required to measure a plurality of physical quantities simultaneously, so that the system structure is large and complex, and the reliability and stability of the system are reduced.

An icp (integrated Circuits piezoelectric) sensor refers to a built-in piezoelectric sensor. The traditional charge amplifier is arranged in the sensor by adopting the modern integrated circuit technology, all high-impedance circuits are sealed in the sensor and output in a low-impedance voltage mode, and the amplitude of the output voltage is in direct proportion to the acceleration. The ICP sensor is a novel acceleration sensor, the output signal of the ICP sensor cannot be directly acquired by an AD acquisition circuit, the ICP sensor must be powered by a constant current source circuit, and the signal of the ICP sensor is conditioned into a form required by a monitoring system. The ICP sensor has the following advantages: (1) the device does not need to be connected with a charge amplifier, is convenient and flexible to use, and is particularly suitable for field test and online monitoring; (2) the ICP sensor has high precision and is not easy to be interfered on site, and because the ICP sensor outputs the amplified signal, the influence of interference on the ICP sensor is small, and the signal-to-noise ratio is high. Even under a severe factory environment, the ICP acceleration sensor can also utilize a common coaxial cable to carry out long-distance transmission on voltage signals; this is why ICP acceleration sensors are widely used, but they require a constant current source to power them.

Piezoelectric acceleration is most widely used in vibration and shock, but since the pressure-sensitive element of the piezoelectric sensor has high impedance, a front-end is required to convert the high-impedance output signal of the sensor into a low-impedance signal. The external preamplifier can be divided into a voltage amplifier and a charge amplifier, the voltage amplifier has simple structure and good linearity and stability, but the sensitivity of the voltage amplifier is influenced by distributed capacitance, and when the length of a connecting cable is changed, the voltage sensitivity is changed accordingly. Although the sensitivity of the charge amplifier is slightly influenced by the distributed capacitance of the cable, when the cable is vibrated and bent, static charges are generated between a cable core wire and an insulator and between the insulator and a metal shielding layer due to relative friction, so that cable noise is caused; these all bring trouble to the test work. An ICP sensor overcomes the above disadvantages compared to a piezoelectric sensor with an external preamplifier.

The large electromechanical equipment has complex operation condition, severe working environment and various interference factors, is easy to be affected by external effects such as impact, friction and the like, and is a problem which is difficult to solve in the design and manufacture of the state monitoring sensor. In the operation state monitoring of large-scale electromechanical equipment, the operation parameters of each key part need to be monitored, if a single parameter sensor is adopted, the number of the sensors is too large, so that the installation is difficult, the monitoring system has a complex structure, the information acquisition is dispersed, and the signal transmission process is easily interfered, thereby bringing certain difficulty to the state monitoring and fault diagnosis of the large-scale electromechanical equipment. The existing large-scale electromechanical equipment state monitoring method mainly comprises the following steps: temperature monitoring, vibration impact monitoring and comprehensive temperature and vibration monitoring. Based on the appearance that the temperature rise is an appearance characteristic of an accident caused by the fact that some parts are broken down and close to the fault, for example, most of passenger trains in China adopt a train axle temperature monitoring alarm device; not all faults necessarily lead to temperature increases (e.g., gear faults, tread faults, and partial bearing face damage), and therefore, integrated temperature and vibration monitoring is commonly used for large electromechanical devices. Practice shows that the single temperature monitoring alarm is incomplete and incomplete, and although the monitoring effect is improved to some extent by a method of comprehensively monitoring temperature and vibration, the method has some problems: the vibration impact monitoring sensor can cause misdiagnosis and misjudgment due to the influence of strong electromagnetic interference, and meanwhile, misdiagnosis or missed diagnosis caused by the failure of a sensitive element can not be avoided. Therefore, it is desirable to make several sensitive components together as much as possible, so that one multi-parameter sensor can measure several parameters simultaneously and has multiple functions, which not only facilitates the installation and maintenance of the state monitoring system of large electromechanical equipment, but also improves the stability and reliability of the monitoring system.

A typical ICP sensor is usually powered by a constant current source, and the power supply cable simultaneously serves as a signal output line to output a low-impedance signal. The whole system comprises the ICP sensor, a common two-core cable and an uninterruptible power supply, and all the ICP systems need the uninterruptible power supply to provide constant current for the ICP sensor. In order to adapt to online state monitoring of large electromechanical equipment, a temperature sensitive element is added on the basis of a typical ICP sensor to form a multi-parameter ICP sensor, and a multi-parameter signal extraction circuit module for the multi-parameter ICP sensor is researched, so that the structure of a monitoring system is optimized, and the stability and reliability of the system are improved; the installation cost, human resources and financial resources of the large-scale electromechanical equipment monitoring system are reduced to a certain extent, a large amount of comprehensive monitoring data can be provided for the monitoring system, the fault diagnosis of the large-scale electromechanical equipment is more accurate and reliable, and the method has important significance for ensuring the operation safety of the large-scale electromechanical equipment. Therefore, it is necessary to develop a current-mode vibration temperature sensor and a multi-parameter interface module thereof.

Disclosure of Invention

To present ICP sensor, sensor signal draw the not enough of aspect existence, the utility model discloses a current mode vibration temperature sensor and many parameter interface module thereof.

The utility model adopts the technical proposal that: a current type vibration temperature sensor and a multi-parameter interface module thereof comprise an ICP sensor, a constant-current constant-voltage source, a signal separation circuit, a subtractor circuit, a full-wave rectification circuit, an envelope demodulation circuit, a low-pass filter circuit and two primary integration circuits, wherein a multi-parameter signal extraction circuit is connected with the ICP sensor arranged on a monitored object through a signal connection component consisting of a connector JK1, a shielded twisted pair and a connector JK 2; the method is characterized in that: the ICP sensor consists of a temperature sensitive element, a vibration impact sensitive element and a detection circuit, the multi-parameter signal extraction circuit comprises a constant-current constant-voltage source and signal separation circuit, a low-pass filtering and integrating circuit, an envelope demodulation circuit and a full-wave rectification and subtracter circuit, the constant-current source is used as a working power supply of the ICP sensor, the constant-current source is used as a working power supply of the multi-parameter signal extraction circuit, and the signal separation circuit is used for separating a direct-current component signal V for removing static working current of the ICP sensor from the power supply of the ICP sensor_DCAC component signal V_AC1And V_AC2And provides the signal DC reference level VREF and AC component signal V for the subsequent circuit_AC2Obtaining a vibration acceleration signal V in the monitoring signal after low-pass filtering_out1Vibration acceleration signal V_out1Obtaining a vibration speed signal V after primary integration_out2Vibration velocity signal V_out2Obtaining a vibration displacement signal V after one-time integration_out3AC component signal V_AC2Impact signal V in monitoring signal after envelope demodulation_out4D.c. component signal V_DCSubtracting the AC component signal V by a subtractor_AC1Obtaining a temperature signal V of the object by the vibration impact DC component after passing through the full wave rectification circuit_out5The problem that the installation space of the monitored object is limited in the monitoring of the running state of the electromechanical equipment is solved, the complex electromagnetic interference under the running working condition of the electromechanical equipment is effectively inhibited, and the structure of the monitoring system is optimized to improve the stability and the reliability.

The utility model discloses in, ICP sensor built-in have temperature sensing element Rt, vibration impact sensing element YDP and detection circuitry, temperature sensing element Rt is Pt series platinum resistance, vibration impact sensing element YDP is piezoceramics crystal, survey the circuit and constitute by two fortune IC1, resistance R1~ R7, electric capacity C1~ C6; the positive pole of the vibration shock sensitive element YDP is connected to a charge amplifier consisting of an operational amplifier IC1B, a resistor R1 and a capacitor C1, the negative pole of the vibration shock sensitive element YDP is connected to the charge amplifier consisting of the operational amplifier IC1A, the resistor R2 and the capacitor C2, a resistor R6 connected to the output ends of the two charge amplifiers is a vibration shock sampling resistor, C5 and C6 are power supply decoupling capacitors, resistors R3, R4 and R5 and the capacitors C3 and C4 together provide signal direct current reference voltage for the two charge amplifiers, differential charge amplification and current sampling are realized on a pickup signal of the vibration shock sensitive element YDP, R1= R2= R3= R, C1= C2= C3= C, the charge variation quantity at two ends of the vibration shock sensitive element YDP caused by monitoring object vibration and shock variation is Q, and the current I6 passes through the resistor R6_d=2Q/(C × R6); the temperature sensitive element Rt and the current limiting resistor R7 are connected in series and then are connected in parallel between the power supply end of the constant current source and the ground GND of the sensor, and the static working current of the ICP sensor is I_qThe current passing through the temperature-sensitive element Rt is I_tThen the sensor operating current I_in=I_q+I_t+I_dThe ICP sensor adopts a two-wire twisted pair connection mode to effectively inhibit complex electromagnetic interference in the signal transmission process.

The utility model discloses in, constant current constant voltage source and signal separation circuit include by constant current chip WD1, diode D1, resistance R18~ R19, the constant current source that electric capacity C8~ C9 is constituteed, by constant voltage chip WD2, the constant voltage source that electric capacity C10~ C13 is constituteed, by the direct current reference level VREF production circuit that IC2B, resistance R11~ R12 are constituteed is put to fortune, by the alternating current component signal V that IC2C and IC2D are put to fortune, resistance R17, electric capacity C7 is constituteed_AC1And V_AC2The separation circuit of (1) is composed of an operational amplifier IC2A, resistors R8-R10 and resistors R13-R16 to form a direct current component signal V_DCThe separation circuit of (1); the ICP sensor is connected to the JK2 through the signal connecting component, and the constant current source transmits signals to the ICP through the sampling resistor R8The sensor providing a varying operating current I_inThe voltage on the sampling resistor R8 changes with the temperature, vibration and impact of the object; the vibration and impact signals of the monitored object are continuous variables, and are AC-coupled to a buffer composed of operational amplifiers IC2C and IC2D through a capacitor C7 to obtain an AC component signal V_AC1And V_AC2The temperature signal of the monitored object is a process variable and is superimposed with a sensor circuit quiescent current I_qA direct current component of the vibration impulse signal, DC-coupled to the direct current component signal V_DCThe resistors R9 and R10 are in accordance with the static working current I of the ICP sensor_qSelectively, subtracting the static working current I of the ICP sensor by a subtracter consisting of an operational amplifier IC2A, a resistor R13= R15 and a resistor R14= R16_qObtaining a DC component signal V after the corresponding voltage_DC(ii) a Since the ICP sensor housing is directly electrically connected to the monitored object, to avoid repeated grounding, the shielding layer of the shielded twisted pair of the signal connection assembly is connected to the constant current source ground through the connector JK 2.

The utility model discloses in, low pass filter and integrator circuit include by fortune put IC3B, resistance R20~ R21, the second order low pass filter that electric capacity C14~ C15 constitutes, by fortune put IC3C, resistance R22~ R23, the second order low pass filter that electric capacity C16~ C17 constitutes, by fortune put IC3D, resistance R24, the first integrator circuit that electric capacity C18 constitutes, by fortune put IC3A, the first integrator circuit that electric capacity R25, electric capacity C19 constitutes; AC component signal V_AC2Outputting a low-frequency vibration acceleration signal V of the monitored object after passing through two second-order low-pass filters_out1For vibration acceleration signal V_out1Obtaining a vibration velocity signal V of the monitored object after primary integration_out2Then for the vibration speed signal V_out2Obtaining the vibration displacement signal V of the monitored object after carrying out primary integration_out3So as to meet the requirements of different signal forms required by different monitoring methods of a subsequent monitoring system.

The utility model discloses in, envelope demodulation circuit include the resonant circuit who comprises switched capacitor filter chip IC4, resistance R26~ R31, electric capacity C20, put IC5, two diodes D2, the letter that resistance R32~ R38 constitutes by two fortuneThe signal detection circuit is a demodulation circuit consisting of a switched capacitor filter chip IC6, resistors R39-R46 and a capacitor C21; the resonance circuit is a fourth-order band-pass filter, the gain and the bandwidth of the resonance circuit can be set according to the characteristics of monitoring signals through resistors R26-R31, the center frequency of the resonance circuit can be adjusted to the natural oscillation frequency of the ICP sensor through a monitoring system output clock BPclk, the demodulation circuit is a fourth-order low-pass filter, the cutoff frequency of the demodulation circuit is configured to be 0.1 time of the center frequency of the resonance circuit through resistors R40-R42 and resistors R43-R46, and the gain of the demodulation circuit is adjusted through a resistor R39 and a resistor R43; AC component signal V_AC2The ICP sensor comprises a high-frequency natural oscillation signal of the ICP sensor caused by the impact of an object, the high-frequency natural oscillation signal is extracted and amplified by a resonance circuit and then is connected to a signal detection circuit, the signal detection circuit converts the negative half cycle of the signal into the positive half cycle of the signal and then is connected to a demodulation circuit, and the demodulation circuit filters out the high-frequency natural frequency in the signal to obtain the envelope curve of the impact signal.

The utility model discloses in, full wave rectification and subtraction circuit include by fortune put IC7A and fortune put IC7B, two diode D3, resistance R47~ R53, full wave rectifier circuit that electric capacity C22 constitutes, by fortune put IC7C, the subtracter that resistance R54~ R57 constitutes; AC component signal V_AC1After passing through full-wave rectifying circuit, the DC component of vibration impact signal is obtained, and then the DC component signal V in subtracter_DCSubtracting the direct current component of the vibration impact signal to obtain a temperature signal V capable of truly reflecting the temperature change of the monitored object_out5Effectively overcomes the defect that the static working current of the ICP sensor is I_qVibration impact sampling current I_dInfluence on the temperature measurement of the object.

The beneficial effects of the utility model are that, the ICP sensor adopts two-wire system constant current source working method, and many parameter signal extraction circuit adopts constant voltage source working method, can extract 5 parameters such as vibration acceleration, vibration speed, vibration displacement, impact, temperature in the monitored object operation, has solved in the monitoring of electromechanical device running state by the limited problem in monitored object installation space, effectively restraines the complicated electromagnetic interference under the electromechanical device operating condition, and then optimizes the monitoring system structure in order to improve stability and reliability.

Drawings

Fig. 1 is a block diagram of the overall structure of the present invention;

fig. 2 is a schematic circuit diagram of an ICP sensor according to an embodiment of the invention;

fig. 3 is a schematic diagram of a constant current source and signal separation circuit according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a low pass filtering and integrating circuit according to an embodiment of the present invention;

fig. 5 is a schematic diagram of an envelope demodulation circuit according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a full-wave rectification and subtraction circuit according to an embodiment of the present invention.

Detailed Description

The technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiment of the present invention; it is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to the drawings, fig. 1 is a block diagram of the overall structure of the present invention. To present ICP sensor, sensing signal draw the not enough of the aspect existence, the utility model discloses a technical scheme be: a current type vibration temperature sensor and a multi-parameter interface module thereof comprise an ICP sensor, a constant-current constant-voltage source, a signal separation circuit, a subtractor circuit, a full-wave rectification circuit, an envelope demodulation circuit, a low-pass filter circuit and two primary integration circuits, wherein a multi-parameter signal extraction circuit is connected with the ICP sensor arranged on a monitored object through a signal connection assembly consisting of a connector JK1, a shielded twisted pair and a connector JK 2. Increase temperature sensing element in order to form on typical ICP sensor's basis the utility model discloses a many parameter ICP sensor, the utility model discloses an ICP sensor comprises temperature sensing element, vibration impact sensing element, detection circuitry, but perception by parameters such as vibration, impact, temperature of monitoring object. Based on the utility modelThe working principle of the novel ICP sensor is that a multi-parameter signal extraction circuit module is further designed; the multi-parameter signal extraction circuit comprises a constant-current constant-voltage source and signal separation circuit, a low-pass filtering and integrating circuit, an envelope demodulation circuit and a full-wave rectification and subtracter circuit, wherein the constant-current source is used as a working power supply of the ICP sensor, the constant-voltage source is used as a working power supply of the multi-parameter signal extraction circuit, and the signal separation circuit is used for separating a direct-current component signal V for removing static working current of the ICP sensor from the power supply of the ICP sensor_DCAC component signal V_AC1And V_AC2And provides the signal DC reference level VREF and AC component signal V for the subsequent circuit_AC2Obtaining a vibration acceleration signal V in the monitoring signal after low-pass filtering_out1Vibration acceleration signal V_out1Obtaining a vibration speed signal V after primary integration_out2Vibration velocity signal V_out2Obtaining a vibration displacement signal V after one-time integration_out3AC component signal V_AC2Impact signal V in monitoring signal after envelope demodulation_out4D.c. component signal V_DCSubtracting the AC component signal V by a subtractor_AC1Obtaining a temperature signal V of the object by the vibration impact DC component after passing through the full wave rectification circuit_out5The problem that the installation space of the monitored object is limited in the monitoring of the running state of the electromechanical equipment is solved, the complex electromagnetic interference under the running working condition of the electromechanical equipment is effectively inhibited, and the structure of the monitoring system is optimized to improve the stability and the reliability.

Fig. 2 is a schematic circuit diagram of an ICP sensor according to an embodiment of the present invention. The ICP sensor is internally provided with a temperature sensitive element Rt, a vibration impact sensitive element YDP and a detection circuit, wherein the temperature sensitive element Rt is a Pt series platinum thermal resistor, the vibration impact sensitive element YDP is a piezoelectric ceramic crystal, and the detection circuit consists of a double operational amplifier IC1, resistors R1-R7 and capacitors C1-C6; the positive pole of the vibration impact sensing element YDP is connected to a charge amplifier consisting of an operational amplifier IC1B, a resistor R1 and a capacitor C1, the negative pole of the vibration impact sensing element YDP is connected to the charge amplifier consisting of an operational amplifier IC1A, a resistor R2 and a capacitor C2, a resistor R6 connected to the output ends of the two charge amplifiers is a vibration impact sampling resistor,c5 and C6 are power supply decoupling capacitors, resistors R3, R4 and R5 and capacitors C3 and C4 together provide signal direct current reference voltages for the two charge amplifiers, differential charge amplification and current sampling of a signal picked up by the vibration shock sensitive element YDP are achieved, R1= R2= R3= R, C1= C2= C3= C is taken, the charge variation quantity at two ends of the vibration shock sensitive element YDP caused by vibration and shock change of a monitored object is Q, and then current I passing through a resistor R6 is obtained_d=2Q/(C × R6); the temperature sensitive element Rt and the current limiting resistor R7 are connected in series and then are connected in parallel between the power supply end of the constant current source and the ground GND of the sensor, and the static working current of the ICP sensor is I_qThe current passing through the temperature-sensitive element Rt is I_tThen the sensor operating current I_in=I_q+I_t+I_dThe ICP sensor adopts a two-wire twisted pair connection mode to effectively inhibit complex electromagnetic interference in the signal transmission process. The utility model discloses in the sensor, IC1, IC2 are two fortune of low-power consumption low noise to put to two fortune, and optional model has: AD8657, LT6004, LTC2067, LT6023, OPA2333, LMP2232, TLV2369, and the like; capacitors C1, C2 and C3 forming the charge amplifier select COG capacitors with better high-frequency noise suppression performance; the sampling resistor R6 is a precision resistor, and the rest resistors are metal film resistors with stable temperature characteristics. The piezoelectric crystal is made of an ionic crystal dielectric medium, and can generate a polarization phenomenon under the action of an electric field force and a mechanical force; namely: when a mechanical force is applied to the dielectrics in a certain direction to generate deformation, the internal positive and negative charge centers of the dielectrics are relatively transferred to generate electric polarization, so that bound charges with opposite signs appear on two opposite surfaces (polarization surfaces) of the dielectrics, and the electric displacement is in proportion to the tensor of the external stress; when the external force disappears, the uncharged state is restored; when the external force changes direction, the polarity of the charges changes accordingly. This phenomenon is called the positive piezoelectric effect, or simply the piezoelectric effect. The utility model discloses the vibration impact sensing device of sensor belongs to piezoelectric type acceleration sensor, adopts annular shearing structural style, and the shearing force on quality piece and the piezoelectric element also changes along with it when receiving the vibration, when the vibration frequency of being measured is far less than the natural frequency of sensor, then the change of power is directly proportional with the acceleration of being measured; the principle of which uses piezoelectricityThe charge output of the crystal is in direct proportion to the force, and the force is in direct proportion to the acceleration value under the condition that the sensitive mass is certain, namely under a certain condition, the charge quantity generated after the piezoelectric crystal is stressed is in direct proportion to the sensed acceleration value. The utility model discloses the main technical indicator of sensor does: the maximum impact acceleration is 10000g, the maximum frequency response frequency is 16kHz, and the requirement of state monitoring of the electromechanical equipment is completely met. The utility model discloses the temperature sensing device encapsulation of sensor is in the trompil of sensor base bottom, and the signal line is drawn forth by the side opening of shell bottom, and the temperature sensing device of sensor is Pt100 temperature sensor. The common Pt100 temperature sensing element comprises a ceramic element, a glass element and a mica element, which are respectively formed by winding a platinum wire on a ceramic skeleton, a glass skeleton and a mica skeleton and then processing the platinum wire by a complex process, wherein the resistance value of a conductor changes along with the temperature change, and the temperature of a measured object is calculated by measuring the resistance value, which is the working principle of the resistance temperature sensor. The Pt100 sensor measures temperature by using the characteristic that the resistance value of a platinum resistor changes along with the temperature change and presents a certain functional relation, and the temperature/resistance value corresponding relation is as follows:

(1) -RPt 100=100[1+ At + Bt2+ Ct (t-100) ] At 200 ℃ < t < 0 ℃;

(2) RPt100=100(1+ At + Bt2) when t is between 0 ℃ and 850 ℃;

wherein A =3.90802 × 10-3, B =5.80 × 10-7, and C =4.2735 × 10-12.

Fig. 3 is a schematic diagram of a constant current source and signal separation circuit according to an embodiment of the present invention. The constant-current constant-voltage source and signal separation circuit comprises a constant-current source consisting of a constant-current chip WD1, a diode D1, resistors R18-R19 and capacitors C8-C9, a constant-voltage source consisting of a constant-voltage chip WD2 and capacitors C10-C13, a direct-current reference level VREF generation circuit consisting of an operational amplifier IC2B and resistors R11-R12, and an alternating-current component signal V consisting of the operational amplifier IC2C, IC2D, the resistor R17 and the capacitor C7_AC1And V_AC2The separation circuit of (1) is composed of an operational amplifier IC2A, resistors R8-R10 and resistors R13-R16 to form a direct current component signal V_DCThe separation circuit of (1); the ICP sensor is connected to the JK2 through the signal connecting component, and the constant current source is used for providing power to the ICP sensor through the sampling resistor R8For varying operating current I_inThe voltage on the sampling resistor R8 changes with the temperature, vibration and impact of the object; the vibration and impact signals of the monitored object are continuous variables, and are AC-coupled to a buffer composed of operational amplifiers IC2C and IC2D through a capacitor C7 to obtain an AC component signal V_AC1And V_AC2The temperature signal of the monitored object is a process variable and is superimposed with a sensor circuit quiescent current I_qA direct current component of the vibration impulse signal, DC-coupled to the direct current component signal V_DCThe resistors R9 and R10 are in accordance with the static working current I of the ICP sensor_qSelectively, subtracting the static working current I of the ICP sensor by a subtracter consisting of an operational amplifier IC2A, a resistor R13= R15 and a resistor R14= R16_qObtaining a DC component signal V after the corresponding voltage_DC(ii) a Since the ICP sensor housing is directly electrically connected to the monitored object, to avoid repeated grounding, the shielding layer of the shielded twisted pair of the signal connection assembly is connected to the constant current source ground through the connector JK 2.

Fig. 4 is a schematic diagram of a low-pass filtering and integrating circuit according to an embodiment of the present invention. The low-pass filtering and integrating circuit comprises a second-order low-pass filter consisting of an operational amplifier IC3B, resistors R20-R21 and capacitors C14-C15, a second-order low-pass filter consisting of an operational amplifier IC3C, resistors R22-R23 and capacitors C16-C17, a primary integrating circuit consisting of an operational amplifier IC3D, a resistor R24 and a capacitor C18, and a primary integrating circuit consisting of an operational amplifier IC3A, a resistor R25 and a capacitor C19; AC component signal V_AC2Outputting a low-frequency vibration acceleration signal V of the monitored object after passing through two second-order low-pass filters_out1For vibration acceleration signal V_out1Obtaining a vibration velocity signal V of the monitored object after primary integration_out2Then for the vibration speed signal V_out2Obtaining the vibration displacement signal V of the monitored object after carrying out primary integration_out3So as to meet the requirements of different signal forms required by different monitoring methods of a subsequent monitoring system.

Fig. 5 is a schematic diagram of an envelope demodulation circuit according to an embodiment of the present invention. The envelope demodulation circuit comprises a resonance circuit consisting of a switched capacitor filter chip IC4, resistors R26-R31 and a capacitor C20,the circuit comprises a signal detection circuit consisting of a double operational amplifier IC5, a double diode D2 and resistors R32-R38, and a demodulation circuit consisting of a switched capacitor filter chip IC6, resistors R39-R46 and a capacitor C21; the resonance circuit is a fourth-order band-pass filter, the gain and the bandwidth of the resonance circuit can be set according to the characteristics of monitoring signals through resistors R26-R31, the center frequency of the resonance circuit can be adjusted to the natural oscillation frequency of the ICP sensor through a monitoring system output clock BPclk, the demodulation circuit is a fourth-order low-pass filter, the cutoff frequency of the demodulation circuit is configured to be 0.1 time of the center frequency of the resonance circuit through resistors R40-R42 and resistors R43-R46, and the gain of the demodulation circuit is adjusted through a resistor R39 and a resistor R43; AC component signal V_AC2The ICP sensor comprises a high-frequency natural oscillation signal of the ICP sensor caused by the impact of an object, the high-frequency natural oscillation signal is extracted and amplified by a resonance circuit and then is connected to a signal detection circuit, the signal detection circuit converts the negative half cycle of the signal into the positive half cycle of the signal and then is connected to a demodulation circuit, and the demodulation circuit filters out the high-frequency natural frequency in the signal to obtain the envelope curve of the impact signal. The filter is an indispensable part in an envelope demodulation circuit, most of the traditional filters are formed by arranging and combining discrete components such as resistors, capacitors, inductors and the like according to a certain mode according to theoretical design, and although the purpose can be achieved, the traditional filters have the defects of complex design process, higher design cost, large occupied space, large power consumption and the like. Not enough to the active RC filter circuit existence among the present envelope demodulator, the utility model provides a wave filter (including resonance circuit's fourth order band pass filter, high pass filter, low pass filter) all adopts the wave filter that uses integrated switch capacitor filter chip as the core. The disadvantages of the active RC filter circuit are: the requirement for large capacitance and accurate RC time constant makes it difficult and almost impossible to fabricate integrated components on a chip; with the rapid development of the MOS technology, the switched capacitor filter composed of MOS switches, capacitors and operational amplifiers has been monolithically integrated in 1975, which has the following advantages: the filter can directly process the discrete value of the analog quantity without an analog-to-digital converter; compared with a digital filter, the method omits the quantization process, thereby having the advantages of high processing speed, simple overall structure and the like. In addition, the switched capacitor filter is simple and inexpensive to manufacture,therefore, with attention paid to all aspects, the performance of the switched capacitor filter has reached a relatively high level after more than 40 years of development, and the switched capacitor filter has a tendency to replace a common active filter in some application occasions. The switched capacitor filter is a discrete time analog filter, as shown in fig. 3, and mainly comprises 3 functional components: the operational amplifier, the MOS switch and the capacitor can realize various filtering functions only by less external resistors; the basic principle of the switched capacitor filter is that a capacitor replaces a resistor, a high-speed switched capacitor is indirectly arranged between two points of a circuit, and the effect of the switched capacitor filter is equivalent to that a resistor is connected between two nodes; compared with a filter formed by discrete components, the integrated filter chip has the advantages of small occupied volume, low power consumption, simple design, low cost and the like. Since 1978, the switched capacitor filter is produced in batches abroad and widely applied to the fields of Pulse Code Modulation (PCM) communication and voice signal processing; companies such as MAXIM, AD, TI and Linear produce switched capacitor filter chips of various models in the United states alone; at present, the products of MAXIM and Linear Technology companies have the advantages of large variety quantity, good performance and optimal frequency and phase characteristics; most switched capacitor filter chips all can be used for realizing the utility model discloses an envelope demodulator, the chip that only is different requires the nonconformity to working power supply, on-off control frequency and the circuit configuration who realizes different function wave filters. The utility model discloses switched capacitor filter chip in the envelope demodulator is preferred: LTC1068 from Linear, MAXIM, MAX7490 or MAX 7491; the LTC1068 is internally provided with 4 monolithic integrated filter blocks with adjustable clocks, and can be used for forming 4 2-order, 2-order or 1 8-order low-pass, band-pass, high-pass and band-stop filters, the highest cut-off frequency can reach 140 kHz, and 24-pin PDIP and 28-pin SSOP2 packages are adopted; the internal structures of the MAX7490 and MAX7491 are completely the same, only the working voltages are different, and MAX7490 is used when the power supply voltage is 5V, and MAX7491 is used when the power supply voltage is 3V; 2 monolithic integrated clock adjustable filter blocks are arranged in the MAX7491, and can be used for forming 2-order or 1 4-order low-pass, band-pass, high-pass and band-stop filters, and the highest central frequency can reach 40 kHz; therefore, only one piece of LTC1068, two pieces of MAX7490 or MAX7491 is needed to realize the utility model discloses a bagAnd a demodulator. In view of the fact that the natural frequency of the vibration impact sensor for monitoring the condition of the rotating machine is difficult to be made very high, generally below 40kHz, the embodiment of the present invention takes MAX7491 as an example. Referring to fig. 5, IC4 and IC6 are a two-way general switched capacitor filter MAX7491, and the two-way general switched capacitor filter MAX is composed of two identical switched capacitor filter modules with biquad topology. MAX7491 adopts 16-pin QSOP packaging, low power consumption design, only + 3V single power supply (or dual power supply) is needed, input and output both have rail-to-rail characteristics, and the maximum central frequency of a designed filter can reach 40 kHz; MAX7491 has high precision, wherein the error rate of quality factor Q is + -0.2%, and the error rate of converting chip working clock into filter center frequency is + -0.2%. The MAX7491 is fast in application design, different filtering functions can be realized by only connecting resistors properly outside a chip, and a low-pass filter, a high-pass filter, a band-pass filter and a band-stop filter can be formed; in addition, by cascading a plurality of filtering modules, it is also possible to configure and construct a high-order filter. All classical filter topologies such as Butterworth, Bessel, elliptic, Chebyshev, etc. can be implemented by MAX7491, and even some user-defined algorithms. In designing the filter, the center frequency of the filter is determined by the MAX7491 operating clock. MAX7491 has two clock sources available: an external clock and an internal oscillator clock with a duty cycle of 50%. Filter center frequency when using external clockf _c (unit: kHz) and the external clock frequency of the chipf _clk(unit: kHz) satisfies the relation:f _c =f _clk/100. When using an internal oscillator clock, a capacitor C needs to be connected externally_OSC(unit: pF), then the oscillator frequencyf _OSC(unit: kHz):f _OSC=135×10³/C_OSC(ii) a The center frequency of the filter is:f _c = f _OSC/100. MAX7491 has 6 modes of operation as follows.

In the table: LP is low-pass filtering, HP is high-pass filtering, BP is band-pass filtering, N is band-stop filtering, and Q is a quality factor;f _c is the center frequency of the filter and,f _clkis the operating frequency of MAX 7491. The resonant circuit in fig. 4 is composed of a switched capacitor filter chip IC4, resistors R26-R31, and a capacitor C20, and is a fourth-order band-pass filter formed by cascading two second-order switched capacitor band-pass filters. Resonance is a common physical phenomenon: if the excitation frequency of the external force is the same as the natural frequency of the object, the object is excited to generate large vibration; if the damping of the object is small, the vibration will tend to be infinite. For any resonant system, regardless of how the repetition frequency of the external action exciting it differs from its natural frequency, the resonance phenomenon of the system will also be excited to occur as long as the higher harmonics of the external action are within a pass band centered at its natural frequency. This unique characteristic of resonance is applied to extract information of the fault impact of the rotary machine deeply buried in the normal vibration information. The envelope demodulation technology is developed from a vibration detection analysis technology, and the traditional vibration analysis technology is to directly perform FFT on a vibration signal and analyze an obtained vibration frequency spectrum; among the spectrum are: the frequency spectrum of the low-frequency vibration caused by factors such as unbalance of a machine rotor, poor centering of a support and the like, the frequency spectrum of the gear meshing frequency vibration and the frequency spectrum of a plurality of orders of the impact caused by bearing fault damage, the spectral lines of the first two factors of the frequency spectrum are very strong, and the spectral line of the fault impact of the rotating machinery is basically invisible; therefore, conventional vibration analysis techniques are not capable of finding information of the rotating machine fault impact. However, an important characteristic of the rotating machine fault impact is that the rotating machine fault impact frequency spectrum can be obtained by applying a high-frequency resonator with a resonant frequency far higher than the conventional vibration frequency, causing the fault impact to generate free attenuation oscillation, namely resonance, demodulating the resonance signal and then performing FFT. The utility model discloses a resonant circuit is by two second order switched capacitor band pass filterThe four-order band-pass filter formed by cascading two filter modules in the same chip of the MAX7491 can be configured into a band-pass filter which can realize 2-stage band-stop filtering, low-pass filtering, band-pass filtering and high-quality factors. If a plurality of chips are cascaded, a high-order Butterworth low-pass filter, a low-Q-value band-stop filter and the like can be realized. The bandwidth and quality factors after MAX7491 concatenation are shown in the table below.

In the table: b is the bandwidth of the cascade front second order band-pass filter, and Q is the quality factor of the cascade front second order band-pass filter. The utility model discloses a mode 1 realization that resonant circuit adopted MAX7491, got R26= R29, R27= R30, R28= R31 and band-pass gain A thereof_BP=(R28/R26)²Band pass center frequencyf _BP=f _clk100, quality factor Q_BP=1.55 (R28/R27). The utility model discloses a detection circuit is an absolute value detection circuit, is put IC5, two diode D2, resistance R32~ R38 by two fortune and constitutes. The input impedance is approximately equal to the parallel connection of the common mode input resistors of the two operational amplifiers and can be up to more than 10M omega. The utility model provides a better metal film resistance of temperature coefficient of characteristics is selected to resistance, and IC5 is put for low-power consumption low noise two fortune in the demodulation circuit to two fortune, and optional model has: AD8572, AD8599, OP285, OP297, LI1012, etc. In the circuit shown in fig. 5, an operational amplifier IC5B, a double diode D2, resistors R32, R33 and R34 form a half-wave detection circuit, and an operational amplifier IC5A, resistors R35, R36, R37 and R38 form an addition circuit. The demodulation circuit is used for converting the negative half cycle of the high-frequency resonance signal output by the resonance circuit through high-pass filtering into the positive half cycle so as to obtain the envelope of fault impact after the subsequent low-pass filtering filters out high-frequency components. The utility model discloses a demodulation circuit is the fourth order low pass filter who comprises two second order switched capacitor low pass filter, comprises switched capacitor filter chip IC6, resistance R39~ R46, electric capacity C21.

Fig. 6 is a full-wave rectification and subtraction circuit according to an embodiment of the present inventionSchematic diagram. The full-wave rectification and subtraction circuit comprises a full-wave rectification circuit consisting of an operational amplifier IC7A, an operational amplifier IC7B, a double diode D3, resistors R47-R53 and a capacitor C22, and a subtractor consisting of an operational amplifier IC7C and resistors R54-R57; AC component signal V_AC1After passing through full-wave rectifying circuit, the DC component of vibration impact signal is obtained, and then the DC component signal V in subtracter_DCSubtracting the direct current component of the vibration impact signal to obtain a temperature signal V capable of truly reflecting the temperature change of the monitored object_out5Effectively overcomes the defect that the static working current of the ICP sensor is I_qVibration impact sampling current I_dInfluence on the temperature measurement of the object.

The utility model discloses IC3, IC7 are low-power consumption low noise fortune and put in well fortune, and optional model has: AD8574, MAX44248, MAX9618, LMP2232, TLV2369, etc.; the capacitor selects a COG capacitor with better high-frequency noise suppression performance; the sampling resistor R8 is a precision resistor, and the rest resistors are metal film resistors with stable temperature characteristics.

To sum up, the utility model discloses a current mode vibration temperature sensor and many parameter interface module thereof, including ICP sensor, constant current constant voltage source, signal separation circuit, subtractor circuit, full wave rectifier circuit, envelope demodulation circuit, low pass filter circuit and 2 integrator circuit, many parameter signal extraction circuit via connector JK1, shielding twisted pair line, the signal connection subassembly that connector JK2 constitutes with to installing the ICP sensor connection on by the object. The utility model has the advantages that: the sensor adopts a measuring line system constant current source working mode, the signal extraction circuit adopts a constant voltage source working mode, 5 parameters such as vibration acceleration, vibration speed, vibration displacement, impact, temperature and the like in the operation of the monitored object can be extracted, the problem that the installation space of the monitored object is limited in the monitoring of the operation state of the electromechanical equipment is solved, the complex electromagnetic interference under the operation condition of the electromechanical equipment is effectively inhibited, and the structure of the monitoring system is further optimized to improve the stability and the reliability.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (6)

1. A current type vibration temperature sensor and a multi-parameter interface module thereof comprise an ICP sensor, a constant-current constant-voltage source, a signal separation circuit, a subtractor circuit, a full-wave rectification circuit, an envelope demodulation circuit, a low-pass filter circuit and two primary integration circuits, wherein a multi-parameter signal extraction circuit is connected with the ICP sensor arranged on a monitored object through a signal connection component consisting of a connector JK1, a shielded twisted pair and a connector JK 2; the method is characterized in that: the ICP sensor consists of a temperature sensitive element, a vibration impact sensitive element and a detection circuit, the multi-parameter signal extraction circuit comprises a constant-current constant-voltage source and signal separation circuit, a low-pass filtering and integrating circuit, an envelope demodulation circuit and a full-wave rectification and subtracter circuit, the constant-current source is used as a working power supply of the ICP sensor, the constant-current source is used as a working power supply of the multi-parameter signal extraction circuit, and the signal separation circuit is used for separating a direct-current component signal V for removing static working current of the ICP sensor from the power supply of the ICP sensor_DCAC component signal V_AC1And V_AC2And provides the signal DC reference level VREF and AC component signal V for the subsequent circuit_AC2Obtaining a vibration acceleration signal V in the monitoring signal after low-pass filtering_out1Vibration acceleration signal V_out1Obtaining a vibration speed signal V after primary integration_out2Vibration velocity signal V_out2Obtaining a vibration displacement signal V after one-time integration_out3AC component signal V_AC2Impact signal V in monitoring signal after envelope demodulation_out4D.c. component signal V_DCSubtracting the AC component signal V by a subtractor_AC1Obtaining a temperature signal V of the object by the vibration impact DC component after passing through the full wave rectification circuit_out5The problem that the installation space of the monitored object is limited in the monitoring of the running state of the electromechanical equipment is solved, the complex electromagnetic interference under the running working condition of the electromechanical equipment is effectively inhibited, and the structure of the monitoring system is optimized to improve the stability and the reliability.

2. A current mode vibration temperature sensor and its multi-parameter interface module according to claim 1, characterized by: the ICP sensor is internally provided with a temperature sensitive element Rt, a vibration impact sensitive element YDP and a detection circuit, wherein the temperature sensitive element Rt is a Pt series platinum thermal resistor, the vibration impact sensitive element YDP is a piezoelectric ceramic crystal, and the detection circuit consists of a double operational amplifier IC1, resistors R1-R7 and capacitors C1-C6; the positive pole of the vibration shock sensitive element YDP is connected to a charge amplifier consisting of an operational amplifier IC1B, a resistor R1 and a capacitor C1, the negative pole of the vibration shock sensitive element YDP is connected to the charge amplifier consisting of the operational amplifier IC1A, the resistor R2 and the capacitor C2, a resistor R6 connected to the output ends of the two charge amplifiers is a vibration shock sampling resistor, C5 and C6 are power supply decoupling capacitors, resistors R3, R4 and R5 and the capacitors C3 and C4 together provide signal direct current reference voltage for the two charge amplifiers, differential charge amplification and current sampling are realized on a pickup signal of the vibration shock sensitive element YDP, R1= R2= R3= R, C1= C2= C3= C, the charge variation quantity at two ends of the vibration shock sensitive element YDP caused by monitoring object vibration and shock variation is Q, and the current I6 passes through the resistor R6_d=2Q/(C × R6); the temperature sensitive element Rt and the current limiting resistor R7 are connected in series and then are connected in parallel between the power supply end of the constant current source and the ground GND of the sensor, and the static working current of the ICP sensor is I_qThe current passing through the temperature-sensitive element Rt is I_tThen the sensor operating current I_in=I_q+I_t+I_dThe ICP sensor adopts a two-wire twisted pair connection mode to effectively inhibit complex electromagnetic interference in the signal transmission process.

3. A current mode vibration temperature sensor and its multi-parameter interface module according to claim 1, characterized by: the constant-current constant-voltage source and signal separation circuit comprises a constant-current source consisting of a constant-current chip WD1, a diode D1, resistors R18-R19 and capacitors C8-C9, a constant-voltage source consisting of a constant-voltage chip WD2 and capacitors C10-C13, a direct-current reference level VREF generation circuit consisting of an operational amplifier IC2B and resistors R11-R12, and an alternating-current component signal consisting of the operational amplifier IC2C, IC2D, the resistor R17 and the capacitor C7V_AC1And V_AC2The separation circuit of (1) is composed of an operational amplifier IC2A, resistors R8-R10 and resistors R13-R16 to form a direct current component signal V_DCThe separation circuit of (1); the ICP sensor is connected to a connector JK2 through a signal connecting component, and a constant current source provides a variable working current I to the ICP sensor through a sampling resistor R8_inThe voltage on the sampling resistor R8 changes with the temperature, vibration and impact of the object; the vibration and impact signals of the monitored object are continuous variables, and are AC-coupled to a buffer composed of operational amplifiers IC2C and IC2D through a capacitor C7 to obtain an AC component signal V_AC1And V_AC2The temperature signal of the monitored object is a process variable and is superimposed with a sensor circuit quiescent current I_qA direct current component of the vibration impulse signal, DC-coupled to the direct current component signal V_DCThe resistors R9 and R10 are in accordance with the static working current I of the ICP sensor_qSelectively, subtracting the static working current I of the ICP sensor by a subtracter consisting of an operational amplifier IC2A, a resistor R13= R15 and a resistor R14= R16_qObtaining a DC component signal V after the corresponding voltage_DC(ii) a Since the ICP sensor housing is directly electrically connected to the monitored object, to avoid repeated grounding, the shielding layer of the shielded twisted pair of the signal connection assembly is connected to the constant current source ground through the connector JK 2.

4. A current mode vibration temperature sensor and its multi-parameter interface module according to claim 1, characterized by: the low-pass filtering and integrating circuit comprises a second-order low-pass filter consisting of an operational amplifier IC3B, resistors R20-R21 and capacitors C14-C15, a second-order low-pass filter consisting of an operational amplifier IC3C, resistors R22-R23 and capacitors C16-C17, a primary integrating circuit consisting of an operational amplifier IC3D, a resistor R24 and a capacitor C18, and a primary integrating circuit consisting of an operational amplifier IC3A, a resistor R25 and a capacitor C19; AC component signal V_AC2Outputting a low-frequency vibration acceleration signal V of the monitored object after passing through two second-order low-pass filters_out1For vibration acceleration signal V_out1Obtaining a vibration velocity signal V of the monitored object after primary integration_out2Then for the vibration speed signal V_out2Perform an integrationThen obtaining the vibration displacement signal V of the monitored object_out3So as to meet the requirements of different signal forms required by different monitoring methods of a subsequent monitoring system.

5. A current mode vibration temperature sensor and its multi-parameter interface module according to claim 1, characterized by: the envelope demodulation circuit comprises a resonance circuit consisting of a switched capacitor filter chip IC4, resistors R26-R31 and a capacitor C20, a signal detection circuit consisting of a double operational amplifier IC5, a double diode D2 and resistors R32-R38, and a demodulation circuit consisting of a switched capacitor filter chip IC6, resistors R39-R46 and a capacitor C21; the resonance circuit is a fourth-order band-pass filter, the gain and the bandwidth of the resonance circuit can be set according to the characteristics of monitoring signals through resistors R26-R31, the center frequency of the resonance circuit can be adjusted to the natural oscillation frequency of the ICP sensor through a monitoring system output clock BPclk, the demodulation circuit is a fourth-order low-pass filter, the cutoff frequency of the demodulation circuit is configured to be 0.1 time of the center frequency of the resonance circuit through resistors R40-R42 and resistors R43-R46, and the gain of the demodulation circuit is adjusted through a resistor R39 and a resistor R43; AC component signal V_AC2The ICP sensor comprises a high-frequency natural oscillation signal of the ICP sensor caused by the impact of an object, the high-frequency natural oscillation signal is extracted and amplified by a resonance circuit and then is connected to a signal detection circuit, the signal detection circuit converts the negative half cycle of the signal into the positive half cycle of the signal and then is connected to a demodulation circuit, and the demodulation circuit filters out the high-frequency natural frequency in the signal to obtain the envelope curve of the impact signal.

6. A current mode vibration temperature sensor and its multi-parameter interface module according to claim 1, characterized by: the full-wave rectification and subtraction circuit comprises a full-wave rectification circuit consisting of an operational amplifier IC7A, an operational amplifier IC7B, a double diode D3, resistors R47-R53 and a capacitor C22, and a subtractor consisting of an operational amplifier IC7C and resistors R54-R57; AC component signal V_AC1After passing through full-wave rectifying circuit, the DC component of vibration impact signal is obtained, and then the DC component signal V in subtracter_DCSubtracting the direct current component of the vibration impact signal to obtain a temperature signal V capable of truly reflecting the temperature change of the monitored object_out5Effectively overcome the ICP transmissionThe static operating current of the inductor is I_qVibration impact sampling current I_dInfluence on the temperature measurement of the object.

Images