CN117760582A - Temperature acquisition system and intelligent diagnosis method thereof - Google Patents
Temperature acquisition system and intelligent diagnosis method thereof Download PDFInfo
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- CN117760582A CN117760582A CN202211127813.8A CN202211127813A CN117760582A CN 117760582 A CN117760582 A CN 117760582A CN 202211127813 A CN202211127813 A CN 202211127813A CN 117760582 A CN117760582 A CN 117760582A
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Abstract
The invention provides a temperature acquisition system and an intelligent diagnosis method thereof, wherein the temperature acquisition system comprises: the temperature sensor comprises a diagnosis control circuit, a constant current source circuit, a temperature sensor, an interface connection circuit and a temperature acquisition circuit, wherein the interface connection circuit is connected with the temperature sensor, the constant current source circuit and the diagnosis control circuit; the temperature acquisition circuit is used for acquiring a measured voltage value of the temperature sensor through the interface connection circuit and transmitting the measured voltage value to the diagnosis control circuit; the diagnosis control circuit controls connection of the interface connection circuit and is used for performing intelligent diagnosis according to the voltage values at the two ends of the first resistor and the measured voltage value and acquiring temperature data. The invention can improve the precision of temperature detection, prevent false alarm, and has high safety and low cost.
Description
Technical Field
The invention belongs to the technical field of temperature detection, and particularly relates to a temperature acquisition system and an intelligent diagnosis method thereof.
Background
The equipment temperature is an important index of the performance of reaction equipment, and along with the continuous development of industry, the temperature measurement range is wider and wider, and the precision requirement is higher and higher. On vehicle equipment, in order to ensure normal and stable operation of a vehicle system, real-time detection of the temperature of the vehicle equipment is an important index reflecting the safety working condition of the vehicle. The vehicle temperature acquisition device comprises motor stator temperature acquisition and axle box temperature acquisition, and the gear box temperature acquisition can effectively improve equipment life and safety by improving the resolution and accuracy of temperature acquisition.
The temperature acquisition in the prior art adopts a discrete device scheme, and comprises a reference current source, temperature acquisition, temperature receiving and control circuits, but the signal chain is longer, the devices are more, the external environment interference is larger, part of the devices possibly fail, and misjudgment and misoperation cannot be avoided. For the integrated device scheme, the current partial Analog-to-digital converter (ADC) outputs from a constant current source with a capacity of being conditioned, and externally supports various temperature acquisitions, but the device has high cost, fewer channels which can be supported by an integrated chip, and channel switching can prolong the acquisition period, so that the integrated device is not practical for mass products.
Disclosure of Invention
The invention provides a temperature acquisition system and an intelligent diagnosis method thereof, which are used for solving the problems that the existing temperature acquisition devices are more, misjudgment and misoperation are easy to occur, and the cost is high.
Based on the above object, an embodiment of the present invention provides a temperature acquisition system, including: the device comprises a diagnosis control circuit, a constant current source circuit, a temperature sensor, an interface connection circuit and a temperature acquisition circuit; the interface connection circuit is connected with the temperature sensor, the constant current source circuit and the diagnosis control circuit, and the constant current source circuit and the temperature acquisition circuit are also connected with the diagnosis control circuit; the diagnosis control circuit controls connection of the interface connection circuit, the constant current source circuit provides a constant current source for the temperature sensor through the interface connection circuit, the interface connection circuit at least comprises a first resistor which is grounded, the temperature acquisition circuit acquires a measured voltage value of the temperature sensor through the interface connection circuit and transmits the measured voltage value to the diagnosis control circuit, and the diagnosis control circuit performs intelligent diagnosis according to the voltage values at two ends of the first resistor and the measured voltage value and acquires temperature data.
Optionally, the interfacing circuit further comprises: the constant current source circuit is connected with the first switch and the second resistor which are connected in series, the second switch is connected with the input end of the temperature acquisition circuit in parallel, one end of the first resistor is connected with the temperature sensor, and the other end of the first resistor is grounded.
Optionally, the interfacing circuit further comprises: a first diode, a second diode, a third diode, and a fourth diode; the cathode of the first diode is connected between the first resistor and the temperature sensor, the cathode of the second diode is connected between the second resistor and the temperature sensor, the cathode of the third diode is connected with the first end of the second switch, the cathode of the fourth diode is connected with the second end of the second switch, and the anode of the first diode, the anode of the second diode, the anode of the third diode and the anode of the fourth diode are grounded.
Optionally, the temperature acquisition circuit includes: the third resistor, the fourth resistor, the first capacitor, the second capacitor and the third capacitor; the temperature sensor at least comprises a first interface and a second interface; the first end of the third resistor is connected with the first interface, and the second end of the third resistor is connected with the diagnosis control circuit and grounded through the second capacitor; the first end of the fourth resistor is connected with the second interface, and the second end of the fourth resistor is connected with the diagnosis control circuit and grounded through the third capacitor; the second end of the third resistor is connected with the second end of the fourth resistor indirectly to the first capacitor.
Optionally, the temperature acquisition circuit further includes a first inductor and a second inductor, the first inductor is connected in series between the third resistor and the first interface, and the second inductor is connected in series between the fourth resistor and the second interface.
Optionally, the constant current source circuit includes: an operational amplifier, a buffer, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor; the inverting input end of the operational amplifier is grounded through the fifth resistor and is connected with the output end of the operational amplifier through the seventh resistor, the non-inverting input end of the operational amplifier is connected with a voltage source through the sixth resistor and is connected with the output end of the buffer through the eighth resistor, the output end of the operational amplifier is connected with one end of the ninth resistor, the other end of the ninth resistor is used as the output end of the constant current source circuit, and the input end of the buffer is connected with the other end of the ninth resistor.
Optionally, the temperature acquisition system further comprises a constant current source diagnosis circuit, wherein the input end of the constant current source diagnosis circuit is connected in parallel with the two ends of the ninth resistor, and the output end of the constant current source diagnosis circuit is connected with the diagnosis control circuit.
Based on the same inventive concept, the embodiment of the invention also provides an intelligent diagnosis method of the temperature acquisition system, which comprises the following steps: acquiring a measured voltage value of a temperature sensor acquired by a temperature acquisition circuit; detecting whether the interface connection circuit and the temperature acquisition circuit are abnormal or not according to the voltage values at two ends of the grounding resistor in the interface connection circuit and the measured voltage values; and acquiring temperature data according to the measured voltage value when the voltage values at the two ends of the grounding resistor are detected to be normal.
Optionally, detecting whether the interface connection circuit and the temperature acquisition circuit are abnormal according to the voltage values of two ends of the ground resistor in the interface connection circuit and the measured voltage value, including: if the voltage values at the two ends of the grounding resistor and the measured voltage value are normal, determining that the interface connection circuit and the temperature acquisition circuit are normal; if the voltage values at the two ends of the grounding resistor are normal and the measured voltage value is 0, determining that the temperature acquisition circuit is short-circuited; if the voltage values at the two ends of the grounding resistor are normal and the measured voltage value is abnormal, determining that the temperature acquisition circuit is disconnected; and if the voltage values at the two ends of the grounding resistor and the measured voltage value are abnormal, determining that the temperature acquisition circuit and the interface connection circuit are short-circuited or broken-circuit simultaneously.
Optionally, the intelligent diagnosis method further includes: the temperature acquisition circuit is used for carrying out temperature acquisition for a plurality of times to acquire a plurality of corresponding temperature data; eliminating deviation data from a plurality of temperature data, and filtering abnormal temperature data by adopting a hold filtering algorithm; and carrying out smooth filtering on the rest temperature data to obtain final temperature data.
The invention has the beneficial effects that as can be seen from the description, the temperature acquisition system and the intelligent diagnosis method thereof provided by the embodiment of the invention comprise the following steps: the device comprises a diagnosis control circuit, a constant current source circuit, a temperature sensor, an interface connection circuit and a temperature acquisition circuit; the interface connection circuit is connected with the temperature sensor, the constant current source circuit and the diagnosis control circuit, and the constant current source circuit and the temperature acquisition circuit are connected with the diagnosis control circuit; the diagnosis control circuit controls connection of the interface connection circuit, the constant current source circuit provides a constant current source for the temperature sensor through the interface connection circuit, the interface connection circuit at least comprises a first resistor which is grounded, the temperature acquisition circuit acquires a measured voltage value of the temperature sensor through the interface connection circuit and transmits the measured voltage value to the diagnosis control circuit, the diagnosis control circuit performs intelligent diagnosis according to the voltage values at two ends of the first resistor and the measured voltage value and acquires temperature data, the precision of temperature detection can be improved, the error-free output of the temperature acquisition device is realized, meanwhile, the problems of misjudgment and misoperation in the temperature acquisition process can be effectively solved, the reliability and safety of a system and equipment are improved, the cost is low, and the economy of the system and the equipment and the general practicability of an interface are also enhanced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a temperature acquisition system according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a specific circuit structure of a constant current source circuit in an embodiment of the present invention;
FIG. 3 is a schematic diagram of a specific circuit structure of a four-wire interface connection of a temperature acquisition circuit according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a system calibration flow in an embodiment of the invention.
Detailed Description
For the purposes of promoting an understanding of the principles and advantages of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same.
It should be noted that unless otherwise defined, technical or scientific terms used in the embodiments of the present invention should be given the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure pertains. The terms "first," "second," and the like, as used in embodiments of the present invention, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.
An embodiment of the present invention provides a temperature acquisition system, as shown in fig. 1, where the temperature acquisition system includes: the diagnosis control circuit 11, the constant current source circuit 12, the temperature sensor 13, the interface connection circuit 14 and the temperature acquisition circuit 15. The interface connection circuit 14 is connected with the temperature sensor 13, the constant current source circuit 12 and the diagnosis control circuit 11, and the constant current source circuit 12 and the temperature acquisition circuit 15 are also connected with the diagnosis control circuit 11; the diagnosis control circuit 11 controls connection of the interface connection circuit 14, the constant current source circuit 12 provides a constant current source for the temperature sensor 13 through the interface connection circuit 14, the interface connection circuit 14 at least comprises a first resistor R1 which is grounded, the temperature acquisition circuit 15 acquires a measured voltage value of the temperature sensor 13 through the interface connection circuit 14 and transmits the measured voltage value to the diagnosis control circuit 11, and the diagnosis control circuit 11 performs intelligent diagnosis according to the voltage values at two ends of the first resistor R1 and the measured voltage value and acquires temperature data. One end of the first resistor R1 is connected to the temperature sensor 13, and the other end is grounded GND.
Wherein the constant current source circuit 12 is used for providing a constant current source for the following temperature sensor 13 through the interface connection circuit 14, the circuit configuration is as shown in fig. 2, and the constant current source circuit 12 comprises: an operational amplifier N1, a buffer N2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9; the inverting input end of the operational amplifier N1 is grounded through the fifth resistor R5 and connected with the output end of the operational amplifier N1 through the seventh resistor R7, the non-inverting input end of the operational amplifier N1 is connected with a voltage source through the sixth resistor R6 and connected with the output end of the buffer N2 through the eighth resistor R8, the output end of the operational amplifier N1 is connected with one end of the ninth resistor R9, the other end of the ninth resistor R9 is used as the output end of the constant current source circuit, and the input end of the buffer N2 is connected with the other end of the ninth resistor R9.
The constant current source circuit 12 is different from a conventional howlan constant current source in which the inverting input terminal of the operational amplifier N1 is grounded through the fifth resistor R5 and connected to the output terminal of the operational amplifier N1 through the seventh resistor R7; the non-inverting input end of the operational amplifier N1 is connected with a voltage source through a sixth resistor R6, and is directly connected with the output end through an eighth resistor R8. In the Howland constant current source, the eighth resistor R8 is large enough to output a constant current, but the eighth resistor R8 is too large to reduce the circuit speed, and a current flows into the non-inverting input terminal of the operational amplifier N1 at the output terminal, which causes a certain error. In the embodiment of the present invention, by serially connecting an inverter or buffer N2 behind the eighth resistor R8, it is possible to ensure that all current flows backward to the temperature sensor PTC as a load. The output current of the constant current source circuit is controlled only by the input voltage provided by the voltage source, so that the constant current source circuit is an ideal constant current source circuit.
If r8/r6=r7/r5=k, the output current of the constant current source circuit 12 is:
the temperature acquisition system further comprises a constant current source diagnosis circuit 16, wherein the input end of the constant current source diagnosis circuit 16 is connected in parallel with the two ends of the ninth resistor R9, and the output end of the constant current source diagnosis circuit 16 is connected with the diagnosis control circuit 16. When a current normally flows through the temperature sensor 13, a voltage V, v= R9, exists across the ninth resistor R9. The constant current source circuit 12 can be specifically designed according to actual current source parameters, and in order to prevent the problem of acquisition accuracy caused by leakage current, the rear end of the constant current source circuit 12 needs to be set to be high-resistance. The diagnosis control circuit 11 also calculates the current value flowing through the two ends of the ninth resistor R9 according to the voltage of the two ends of the ninth resistor R9 acquired by the constant current source diagnosis circuit 16, compares the current value with the actual application design value, obtains an accurate current error coefficient through multiple sampling, calculates the measured voltage value of the temperature sensor 13 acquired by the temperature acquisition circuit 15 according to the current error coefficient, finally acquires the temperature data of the temperature sensor 13, and improves the detection precision. If the value of the constant current source is displayed to be too high to exceed the range during diagnosis, the diagnosis value is inaccurate, and a fault alarm indication can be set. The current output by the constant current source circuit 12 flows back into the interface connection circuit 14 and the temperature sensor 13 to facilitate temperature collection.
In an embodiment of the present invention, the temperature sensor 13 is preferably a positive temperature coefficient (Positive Temperature Coefficient, PTC) thermistor. Of course the temperature sensor 13 may also be a negative temperature coefficient thermistor NTC. The external connection modes of the temperature sensor 13 include two-wire system, three-wire system and four-wire system, and the four-wire system is taken as an example for the following description, and the temperature sensor 13 includes 4 interfaces in total, namely, the first interface 1, the second interface 2, the third interface 3 and the fourth interface 4.
As shown in fig. 3, the interfacing circuit 14 further includes: the constant current source circuit 12 is connected with the first switch K1 and the second resistor R2 in series, the second switch K2 is connected with the temperature sensor 13 in parallel with the input end of the temperature acquisition circuit 15, one end of the first resistor R1 is connected with the temperature sensor 13, and the other end is grounded GND. Specifically, two ends of the second switch K2 are respectively connected with the first interface 1 and the second interface 2 of the temperature sensor 13, the first resistor R1 is connected with the fourth interface 4 of the temperature sensor 13, and one end of the second resistor R2 is connected with the third interface 3 of the temperature sensor 13. The first switch K1 is used for controlling the input of the constant current source circuit 12; the second switch K2 is used for controlling the opening and closing of the temperature acquisition channel. The second resistor R2 is connected in series to perform overcurrent protection so as to prevent the internal circuit from being burnt out due to overlarge external interference; the first resistor R1 is grounded GND for forming a current loop. Under normal conditions, the first switch K1 is closed, the second switch K2 is opened, and normal temperature acquisition is carried out; under the self-checking condition, the first switch K1 is opened, the second switch K2 is closed, the output of the constant current source circuit 12 is opened, the power VCC is sent to the collecting channel, the collecting channel is closed, and the self-checking of the interface connection circuit 14 is performed. The VCC voltage range can be adjusted according to the rear end acquisition range, the first switch K1 and the second switch K2 can be adjusted according to practical application, and an analog switch or a relay can be selected.
The interfacing circuit 14 further includes: a first diode V1, a second diode V2, a third diode V3, and a fourth diode V4; the cathode of the first diode V1 is connected between the second resistor R2 and the temperature sensor 13, the cathode of the second diode V2 is connected between the first resistor R1 and the temperature sensor 13, the cathode of the third diode V3 is connected with the first end of the second switch K2, the cathode of the fourth diode V4 is connected with the second end of the second switch K2, and the anode of the first diode V1, the anode of the second diode V2, the anode of the third diode V3 and the anode of the fourth diode V4 are grounded. The first diode V1, the second diode V2, the third diode V3, and the fourth diode V4 all play a role in surge protection, and in order to prevent an error caused by an excessive leakage current, the clamping voltage value cannot be too small.
With continued reference to fig. 3, the temperature acquisition circuit 15 includes: the third resistor R3, the fourth resistor R4, the first capacitor C1, the second capacitor C2, and the third capacitor C3. The temperature sensor 13 comprises at least a first interface 1 and a second interface 2; a first end of the third resistor R3 is connected to the first interface 1, and a second end of the third resistor R3 is connected to the diagnostic control circuit 11 and is grounded GND through the second capacitor C2; the first end of the fourth resistor R4 is connected to the second interface 2, and the second end of the fourth resistor R4 is connected to the diagnostic control circuit 11 and is grounded GND through the third capacitor C3; the second end of the third resistor R3 is connected to the second end of the fourth resistor R4 via the first capacitor C1. The cathode of the third diode V3 and the first end of the second switch K2 are connected to the first interface 1 of the temperature sensor 13, and the cathode of the fourth diode V4 and the second end of the second switch K2 are connected to the second interface 2 of the temperature sensor 13. The third resistor R3, the fourth resistor R4, the first capacitor C1, the second capacitor C2 and the third capacitor C3 jointly form an RC filter circuit: the third resistor R3, the fourth resistor R4, the second capacitor C2 and the third capacitor C3 are subjected to common-mode interference filtering; the third resistor R3, the fourth resistor R4, the first capacitor C1, the second capacitor C2 and the third capacitor C3 perform differential mode interference filtering, and the specific bandwidth can be adjusted according to the practical application of the rear end.
The temperature acquisition circuit 15 further includes a first inductor L1 and a second inductor L2, where the first inductor L1 is connected in series between the third resistor R3 and the first interface 1, and the second inductor L2 is connected in series between the fourth resistor R4 and the second interface 2. The first inductor L1 and the second inductor L2 can function to suppress high-frequency interference.
Other wire systems may incorporate part of the line interfaces in the case of a four-wire system, for example, a two-wire system may connect the third interface 3 of the temperature sensor 13 in the four-wire system with the first interface 1, i.e. one end of the second resistor R2 and the first end of the second switch K2 share one interface; the second interface 2 is connected to the fourth interface 4, i.e. the second end of the second switch K2 and one end of the first resistor R1 share one interface. The three-wire system only needs to connect the first interface 1 and the third interface 3 of the four-wire system middle temperature sensor 13 together.
The temperature acquisition system of the embodiment of the invention comprises: a diagnosis control circuit 11, a constant current source circuit 12, a temperature sensor 13, an interface connection circuit 14 and a temperature acquisition circuit 15; the interface connection circuit 14 is connected with the temperature sensor 13, the constant current source circuit 12 and the diagnosis control circuit 11, and the constant current source circuit 12 and the temperature acquisition circuit 15 are also connected with the diagnosis control circuit 11; the diagnosis control circuit 11 controls the connection of the interface connection circuit 14, the constant current source circuit 12 provides a constant current source for the temperature sensor 13 through the interface connection circuit 14, the interface connection circuit 14 at least comprises a first resistor R1 which is grounded, the temperature acquisition circuit 15 acquires a measured voltage value of the temperature sensor 13 through the interface connection circuit 14 and transmits the measured voltage value to the diagnosis control circuit 11, the diagnosis control circuit 11 performs intelligent diagnosis and acquires temperature data according to the voltage values at two ends of the first resistor R1 and the measured voltage value, the precision of temperature detection can be improved, the error-free output of the temperature acquisition device is realized, meanwhile, the problems of error judgment and error operation in the temperature acquisition process can be effectively solved, the reliability and the safety of a system and equipment are improved, the cost is low, and the economical efficiency of the system and the equipment and the practicability of the interface are also enhanced.
Based on the same inventive concept, the embodiment of the present invention further provides an intelligent diagnosis method of a temperature acquisition system, which is applied to the foregoing diagnosis control circuit 11, as shown in fig. 4, and includes:
step S11: the measured voltage value of the temperature sensor 13 acquired by the temperature acquisition circuit 15 is acquired.
When the temperature sensor 13 takes a thermistor as an example and the temperature acquisition system performs normal temperature acquisition, the constant current source circuit 12 outputs current to the temperature sensor 13 and is grounded GND through the first resistor R1 to form a current loop, the thermistor heats, the resistance value correspondingly changes, the temperature acquisition circuit 15 acquires measurement voltage values at two ends of the thermistor and transmits the measurement voltage values to the diagnosis control circuit 11, and the diagnosis control circuit 11 acquires the measurement voltage values.
Step S12: and detecting whether the interface connection circuit 14 and the temperature acquisition circuit 15 are abnormal or not according to the voltage values of the two ends of the grounding resistor in the interface connection circuit 14 and the measured voltage values.
The ground resistance is the first resistance R1. In the embodiment of the invention, if only the wiring of the temperature acquisition circuit 15 is disconnected, the voltage values of the two ends of the grounding resistor in the current loop of the constant current source circuit 12 are normal, and the measured voltage value of the temperature sensor 13 is abnormal; if the wiring of the constant current source circuit 12 is disconnected or if the wiring of the constant current source circuit 12 and the wiring of the temperature acquisition circuit 15 are simultaneously disconnected, the measured voltage value of the temperature sensor 13 and the voltage value across the ground resistance in the current loop of the constant current source circuit 12 are abnormal. If the wiring of the temperature acquisition circuit 15 is shorted, the acquired resistance value of the temperature sensor 13 is 0, that is, the measured voltage value of the temperature sensor 13 is 0, at this time, the voltage values of the two ends of the ground resistor in the current loop of the constant current source circuit 12 are normal, and the measured voltage value of the temperature sensor 13 is abnormal. If the wiring of the constant current source circuit 12 is short-circuited or if the wiring of the constant current source circuit 12 and the wiring of the temperature acquisition circuit 15 are short-circuited at the same time, no current flows through the temperature sensor 13, and at this time, the measured voltage value of the temperature sensor 13 and the voltage value across the ground resistor in the current loop of the constant current source circuit 12 are abnormal. In practical applications, the disconnection and short-circuit states are not distinguished, and can be judged by whether the minimum resistance value of the temperature sensor 13 is exceeded.
Therefore, in step S12, if the voltage values at both ends of the ground resistor and the measured voltage value are normal, it is determined that the interface connection circuit 14 and the temperature acquisition circuit 15 are normal; if the voltage values at the two ends of the grounding resistor are normal and the measured voltage value is 0, determining that the temperature acquisition circuit 15 is short-circuited; if the voltage values at the two ends of the grounding resistor are normal and the measured voltage value is abnormal, determining that the temperature acquisition circuit 15 is disconnected; if the voltage values at both ends of the ground resistor and the measured voltage values are abnormal, it is determined that the temperature acquisition circuit 15 and the interfacing circuit 14 simultaneously short-circuit or open-circuit faults.
According to the fact that the difference between the measured voltage value of the temperature sensor measured by the temperature acquisition circuit 15 and the normal value is large after comparison, if the temperature sensor is in a multi-channel application occasion, a multiplexer can be selected to switch the output of the constant current source circuit, and whether a current loop has faults or not can be detected again.
Step S13: and acquiring temperature data according to the measured voltage value when the voltage values at the two ends of the grounding resistor are detected to be normal.
In order to avoid false triggering caused by poor contact or other actions due to external environment interference or train shake and the like, the embodiment of the invention also introduces a software calibration function. Optionally, the temperature acquisition circuit is used for carrying out temperature acquisition for a plurality of times to obtain a plurality of corresponding temperature data; eliminating deviation data from a plurality of temperature data, and filtering abnormal temperature data by adopting a hold filtering algorithm; and carrying out smooth filtering on the rest temperature data to obtain final temperature data. Namely, in the temperature acquisition and calculation process, multiple times of filtering processing are needed: firstly, the temperature is acquired for multiple times according to the actual sampling period condition, then, the deviation value is removed according to the sampling number, the maximum value and the minimum value are generally taken as the main values, and finally, the average sampling value is calculated according to the residual sampling number. Under the condition of larger interference, a sampling hold filtering algorithm is introduced, namely the last sampling value and the current sampling value are balanced according to coefficients, so that false alarm triggered by larger interference in a short time is avoided. The embodiment of the invention also introduces constant current source calibration, and in the multi-channel application occasion, a multiplexer can be selected to switch the output of the constant current source circuit, so as to improve the single board integration level and reduce the system cost, and the invention is of great importance to the calibration and control of the constant current source. The constant current source calibration is to introduce system calibration on constant current source diagnosis and power failure, calculate the current value flowing through the two ends of the ninth resistor R9 by collecting the voltage of the two ends of the ninth resistor R9 as constant current source output conditioning resistor, compare with the actual application design value, obtain an accurate current error coefficient by multiple sampling, and introduce the accurate current error coefficient into the calculation of the rear end temperature collection, thereby improving the detection precision, and if the deviation is larger, the current loop needs to be re-detected whether to have faults or not.
The foregoing describes certain embodiments of the present invention. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.
Those of ordinary skill in the art will appreciate that: the discussion of any of the embodiments above is merely exemplary and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples; the technical features of the above embodiments or in the different embodiments may also be combined under the concepts of the present disclosure, the steps may be implemented in any order, and there are many other variations of the different aspects of one or more embodiments in this application as described above, which are not provided in detail for the sake of brevity.
The present application is intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Any omissions, modifications, equivalents, improvements, and the like, which are within the spirit and principles of the one or more embodiments in the present application, are therefore intended to be included within the scope of the present disclosure.
Claims (10)
1. A temperature acquisition system, the temperature acquisition system comprising: the device comprises a diagnosis control circuit, a constant current source circuit, a temperature sensor, an interface connection circuit and a temperature acquisition circuit; the interface connection circuit is connected with the temperature sensor, the constant current source circuit and the diagnosis control circuit, and the constant current source circuit and the temperature acquisition circuit are also connected with the diagnosis control circuit; the diagnosis control circuit controls connection of the interface connection circuit, the constant current source circuit provides a constant current source for the temperature sensor through the interface connection circuit, the interface connection circuit at least comprises a first resistor which is grounded, the temperature acquisition circuit acquires a measured voltage value of the temperature sensor through the interface connection circuit and transmits the measured voltage value to the diagnosis control circuit, and the diagnosis control circuit performs intelligent diagnosis according to the voltage values at two ends of the first resistor and the measured voltage value and acquires temperature data.
2. The temperature acquisition system of claim 1, wherein the interfacing circuit further comprises: the constant current source circuit is connected with the first switch and the second resistor which are connected in series, the second switch is connected with the input end of the temperature acquisition circuit in parallel, one end of the first resistor is connected with the temperature sensor, and the other end of the first resistor is grounded.
3. The temperature acquisition system of claim 2, wherein the interfacing circuit further comprises: a first diode, a second diode, a third diode, and a fourth diode; the cathode of the first diode is connected between the first resistor and the temperature sensor, the cathode of the second diode is connected between the second resistor and the temperature sensor, the cathode of the third diode is connected with the first end of the second switch, the cathode of the fourth diode is connected with the second end of the second switch, and the anode of the first diode, the anode of the second diode, the anode of the third diode and the anode of the fourth diode are grounded.
4. The temperature acquisition system of claim 1, wherein the temperature acquisition circuit comprises: the third resistor, the fourth resistor, the first capacitor, the second capacitor and the third capacitor; the temperature sensor at least comprises a first interface and a second interface; the first end of the third resistor is connected with the first interface, and the second end of the third resistor is connected with the diagnosis control circuit and grounded through the second capacitor; the first end of the fourth resistor is connected with the second interface, and the second end of the fourth resistor is connected with the diagnosis control circuit and grounded through the third capacitor; the second end of the third resistor is connected with the second end of the fourth resistor indirectly to the first capacitor.
5. The temperature acquisition system of claim 4 wherein the temperature acquisition circuit further comprises a first inductance and a second inductance, the first inductance being connected in series between the third resistor and the first interface, the second inductance being connected in series between the fourth resistor and the second interface.
6. The temperature acquisition system according to claim 1, wherein the constant current source circuit includes: an operational amplifier, a buffer, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor and a ninth resistor; the inverting input end of the operational amplifier is grounded through the fifth resistor and is connected with the output end of the operational amplifier through the seventh resistor, the non-inverting input end of the operational amplifier is connected with a voltage source through the sixth resistor and is connected with the output end of the buffer through the eighth resistor, the output end of the operational amplifier is connected with one end of the ninth resistor, the other end of the ninth resistor is used as the output end of the constant current source circuit, and the input end of the buffer is connected with the other end of the ninth resistor.
7. The temperature acquisition system according to claim 6, wherein the constant current source circuit further comprises a constant current source diagnostic circuit, an input end of the constant current source diagnostic circuit is connected in parallel to both ends of the ninth resistor, and an output end of the constant current source diagnostic circuit is connected with the diagnostic control circuit.
8. A method of intelligent diagnosis of a temperature acquisition system according to any one of claims 1 to 7, characterized in that the method comprises:
acquiring a measured voltage value of a temperature sensor acquired by a temperature acquisition circuit;
detecting whether the interface connection circuit and the temperature acquisition circuit are abnormal or not according to the voltage values at two ends of the grounding resistor in the interface connection circuit and the measured voltage values;
and acquiring temperature data according to the measured voltage value when the voltage values at the two ends of the grounding resistor are detected to be normal.
9. The intelligent diagnosis method of the temperature acquisition system according to claim 8, wherein the detecting whether the interface connection circuit and the temperature acquisition circuit are abnormal according to the voltage value of both ends of the ground resistor in the interface connection circuit and the measured voltage value comprises:
if the voltage values at the two ends of the grounding resistor and the measured voltage value are normal, determining that the interface connection circuit and the temperature acquisition circuit are normal;
if the voltage values at the two ends of the grounding resistor are normal and the measured voltage value is 0, determining that the temperature acquisition circuit is short-circuited;
if the voltage values at the two ends of the grounding resistor are normal and the measured voltage value is abnormal, determining that the temperature acquisition circuit is disconnected;
and if the voltage values at the two ends of the grounding resistor and the measured voltage value are abnormal, determining that the temperature acquisition circuit and the interface connection circuit are short-circuited or broken-circuit simultaneously.
10. The intelligent diagnostic method of a temperature acquisition system according to claim 8, wherein the method further comprises:
the temperature acquisition circuit is used for carrying out temperature acquisition for a plurality of times to acquire a plurality of corresponding temperature data;
eliminating deviation data from a plurality of temperature data, and filtering abnormal temperature data by adopting a hold filtering algorithm;
and carrying out smooth filtering on the rest temperature data to obtain final temperature data.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211127813.8A CN117760582A (en) | 2022-09-16 | 2022-09-16 | Temperature acquisition system and intelligent diagnosis method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211127813.8A CN117760582A (en) | 2022-09-16 | 2022-09-16 | Temperature acquisition system and intelligent diagnosis method thereof |
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