Platinum thermistor signal analog simulation circuit and simulation method

Abstract

The invention provides a platinum thermistor signal analog simulation circuit and a platinum thermistor signal analog simulation method. The platinum thermistor signal analog simulation circuit comprises a current / voltage conversion module used for converting an input excitation current Ii into an excitation voltage Vi; the amplification module is used for amplifying the excitation voltage Vi based on the simulated platinum thermal resistors of different types and outputting reference voltage VR; the control quantity conversion module is used for calculating a control quantity C based on the expected analog simulation temperature T and according to a preset resolution; and the normal conversion DAC is used for calculating the output voltage Vo according to the input control quantity C, the preset resolution and the reference voltage VR. According to the platinum thermal resistor signal analog simulation circuit and the simulation method provided by the invention, the problem of platinum thermal resistor signal simulation under high precision is solved, and the signal simulation of different types of platinum thermal resistors can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of simulation testing, and in particular to a platinum thermal resistor signal simulation circuit and a simulation method. Background Art

[0002] At present, in the fields of aerospace, high-speed rail, automobile, precision machinery, industrial automation, etc., the design verification of the control system requirements of the developed electronic controller in the hardware-in-the-loop system has become a common and indispensable part of the development process. Using the hardware-in-the-loop simulation system to simulate the input signal of the electronic controller in real time and accurately has become a typical requirement for the functional verification of the control system.

[0003] Temperature is a common quantity used in electronic controller calculation and logic judgment, and is a common input signal of electronic controller. Thermal resistors are the most commonly used temperature detectors in medium and low temperature zones, with advantages such as high measurement accuracy, small size, and stable performance. Among them, the most widely used is platinum thermal resistors, which measure temperature based on the characteristic that the resistance value of a conductor or semiconductor changes with temperature.

[0004] In the hardware-in-the-loop test environment, there is a need to verify the logic of the electronic controller control logic under different temperature inputs and to calibrate and verify the temperature measurement channel of the electronic controller. Therefore, the hardware-in-the-loop test platform needs to have the ability to simulate common types of thermal resistor sensors with high accuracy. At the same time, the hardware-in-the-loop test platform should have the ability to switch modes to match the measurement requirements for different types of platinum thermal resistors (PT100, PT200 or PT1000, etc.) that may be selected by the electronic controller. However, the current simulation system of the hardware-in-the-loop test still has problems such as poor simulation accuracy of platinum thermal resistors and the inability to switch the simulation type of platinum thermal resistors to adapt to the input signal requirements of the electronic controller. Summary of the invention

[0005] In view of the above problems in the prior art, the present invention proposes a platinum thermal resistor signal simulation circuit and simulation method, which solves the problem of platinum thermal resistor signal simulation under high precision and can realize signal simulation of different types of platinum thermal resistors.

[0006] Specifically, the present invention proposes a platinum thermal resistance signal simulation circuit, comprising:

[0007] A current / voltage conversion module, used for converting the input excitation current Ii into an excitation voltage Vi;

[0008] an amplifying module, amplifying the excitation voltage Vi based on the simulated different types of platinum thermal resistors, and outputting a reference voltage VR;

[0009] A control quantity conversion module, used for calculating the control quantity C based on the desired simulated temperature T and according to a preset resolution;

[0010] The method conversion DAC is used to calculate the output voltage Vo according to the input control quantity C, the preset resolution and the reference voltage VR.

[0011] According to an embodiment of the present invention, if the analog simulation circuit is used to simulate a PT100 thermal resistor, the sampling resistor of the current / voltage conversion module is set to R0, the amplification factor of the amplification module is K, and the resolution is 16Bit;

[0012] Then the excitation voltage Vi is: V i =I i ·R0 formula 1;

[0013] The reference voltage VR is: V R =K·V i =K·I i ·R0 formula 2;

[0014] The output voltage Vo is converted to DAC by the method:

[0015]

[0016] According to formula 1-3, the voltage difference VD between the output voltage Vo and the excitation voltage Vi is:

[0017]

[0018] The resistance value RT of the simulated platinum thermal resistor is:

[0019]

[0020] Get the function of resistance value RT and temperature T:

[0021]

[0022] Among them, A, B, C and R100 are known constants. Based on the sampling resistor R0 and the amplification factor K, the control quantity C is obtained by solving formula 5-6.

[0023] According to an embodiment of the present invention, the sampling resistor R0 is 20Ω, the amplification factor K of the amplification module is 20, and the temperature T is between -200° C. and 850° C., then the simulation range of the resistance value RT is 20Ω to 400Ω.

[0024] According to one embodiment of the present invention, the current / voltage conversion module includes a sampling resistor R0 and a comparator U1, the positive input terminal of the comparator U1 is the input terminal of the excitation current Ii, the positive input terminal of the comparator U1 is grounded through the sampling resistor R0, the reverse input terminal of the comparator U1 is connected to the output terminal, and the comparator U1 outputs the excitation voltage Vi.

[0025] According to one embodiment of the present invention, the amplification module includes a comparator U2, a resistor R1, a resistor R2 and a resistor R3, the output end of the comparator U1 is connected to the negative end of the comparator U2 via the resistor R2, the negative end of the comparator U2 is connected to the output end of the comparator U2 via the resistor R3, the positive end of the comparator U2 is grounded through the resistor R1, and the comparator U2 outputs a reference voltage VR.

[0026] According to one embodiment of the present invention, the excitation voltage Vi converted by the current / voltage conversion module is: V i =I i R0;

[0027] After amplification by the amplification module, the reference voltage VR is:

[0028]

[0029] According to one embodiment of the present invention, the resistor R2 is 1KΩ, the resistor R3 is 20KΩ, and the reference voltage VR is:

[0030]

[0031] The present invention also provides a platinum thermal resistance signal simulation method, comprising the steps of:

[0032] S1, generating an excitation current Ii, and converting the excitation current Ii into an excitation voltage Vi;

[0033] S2, amplifying the excitation voltage Vi based on the simulated different types of platinum thermal resistors to obtain a reference voltage VR; calculating the control amount C based on the desired simulated temperature T and according to a preset resolution;

[0034] S3, calculating and simulating the output voltage Vo of the platinum thermal resistor according to the input control quantity C, the preset resolution and the reference voltage VR.

[0035] According to an embodiment of the present invention, if used to simulate a PT100 thermal resistor, the sampling resistor used in step S1 is assumed to be R0, the amplification factor of the excitation voltage Vi in step S2 is K, and the resolution is 16 Bit;

[0036] Then the excitation voltage Vi is: V i =Ii ·R0 formula 1;

[0037] The reference voltage VR is: V R =K·V i =K·I i ·R0 formula 2;

[0038] The output voltage Vo is:

[0039]

[0040] According to formula 1-3, the voltage difference VD between the output voltage Vo and the excitation voltage Vi is:

[0041]

[0042] The resistance value RT of the simulated platinum thermal resistor is:

[0043]

[0044] Get the function of resistance value RT and temperature T:

[0045]

[0046] Among them, A, B, C and R100 are known constants. Based on the sampling resistor R0 and the amplification factor K, the control quantity C is obtained by solving formula 5-6.

[0047] According to an embodiment of the present invention, the sampling resistor R0 is 20Ω, the amplification factor K of the amplification module is 20, and the temperature T is between -200° C. and 850° C., then the simulation range of the resistance value RT is 20Ω to 400Ω.

[0048] The present invention provides a platinum thermal resistor signal simulation circuit and simulation method, which solves the platinum thermal resistor signal simulation under high precision through a current / voltage conversion module, an amplification module, a control quantity conversion module and a method conversion DAC, and can realize signal simulation of different types of platinum thermal resistors.

[0049] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this application. The accompanying drawings illustrate embodiments of the present invention and together with the description serve to explain the principle of the present invention.

[0051] In the attached figure:

[0052] Figure 1 A schematic diagram of the structure of a platinum thermal resistor signal simulation circuit according to an embodiment of the present invention is shown.

[0053] Figure 2 A circuit diagram of a current / voltage conversion module and an amplification module according to an embodiment of the present invention is shown.

[0054] Figure 3 A flow chart of a platinum thermal resistor signal simulation method according to an embodiment of the present invention is shown.

[0055] The above drawings include the following reference numerals:

[0056] Analog Simulation Circuit 100

[0057] Compressor 101

[0058] The first four-way valve 102

[0059] Second four-way valve 103 DETAILED DESCRIPTION

[0060] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0061] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0062] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0063] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0064] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0065] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0066] Figure 1 The structure diagram of a platinum thermal resistor signal simulation circuit according to an embodiment of the present invention is shown. As shown in the figure, a platinum thermal resistor signal simulation circuit 100 mainly includes a current / voltage conversion module 101, an amplification module 102, a control quantity conversion module 103 and a method conversion DAC 104.

[0067] The current / voltage conversion module 101 is used to convert the input excitation current Ii into an excitation voltage Vi;

[0068] The amplification module 102 amplifies the excitation voltage Vi based on the simulated different types of platinum thermal resistors and outputs a reference voltage VR. The different types of platinum thermal resistors may be PT100, PT200 or PT1000.

[0069] The control amount conversion module 103 is used to calculate the control amount C based on the desired simulation temperature T and according to a preset resolution;

[0070] The conversion DAC 104 is used to calculate the output voltage Vo according to the input control variable C, the preset resolution and the reference voltage VR.

[0071] The present invention provides a platinum thermal resistor signal simulation circuit 100. When an excitation current Ii and a desired simulation temperature T are input, the output voltage Vo of the platinum thermal resistor can be simulated according to the calculated control quantity C, thereby realizing signal simulation of different types of platinum thermal resistors. According to the preset resolution, the accuracy of platinum thermal resistor signal simulation can be improved. The implementation principle is to simulate the electrical characteristics of the thermal resistor when it is working: after the set temperature T is input, the thermal resistor simulation circuit shows the resistance value at the corresponding temperature under the excitation. According to Ohm's law, the resistance is equal to the voltage divided by the current, that is, the simulation circuit needs to simulate the corresponding output voltage Vo.

[0072] Preferably, if the analog simulation circuit 100 is used to simulate a PT100 thermal resistor, the sampling resistor of the current / voltage conversion module 101 is set to R0, the multiple of the amplified excitation voltage Vi of the amplification module 102 is K, and the configuration resolution is 16Bit;

[0073]

[0074] The reference voltage VR is: V R =K·V i =K·I i ·R0 formula 2;

[0075] By converting the DAC 104 and the preset resolution, the output voltage Vo is calculated as:

[0076]

[0077] According to formula 1-3, the voltage difference VD between the output voltage Vo and the excitation voltage Vi is:

[0078]

[0079] Then the resistance value RT of the simulated PT100 thermal resistor is:

[0080]

[0081] Get the function of resistance value RT and temperature T:

[0082]

[0083] Among them, A, B, C and R100 are known constants. Based on the sampling resistor R0 and the amplification factor K, the control quantity C is obtained by solving formula 5-6.

[0084] It is easy to understand that according to the type of platinum thermal resistor to be simulated, the amplification factor of the amplifier module 102 and the resistance value of the sampling resistor R0 are determined, and the control quantity C can be calculated based on the set temperature T, excitation current Ii and resolution to ensure that the final output voltage Vo meets the simulation requirements.

[0085] Preferably, the platinum thermal resistor PT100 is simulated, the sampling resistor R0 is 20Ω, the amplification factor K of the amplifier module 102 is 20, and when the temperature T is between -200°C and 850°C, the simulation range of the resistance value RT of the simulated platinum thermal resistor PT100 is 20Ω to 400Ω, and the actual range is approximately between 18.4Ω and 390.5Ω.

[0086] Figure 2 The circuit diagram of the current / voltage conversion module 101 and the amplification module 102 of an embodiment of the present invention is shown. Preferably, as shown in the figure, the current / voltage conversion module 101 includes a sampling resistor R0 and a comparator U1. The positive input terminal of the comparator U1 is the input terminal of the excitation current Ii, the positive input terminal of the comparator U1 is grounded through the sampling resistor R0, the reverse input terminal of the comparator U1 is connected to the output terminal, and the comparator U1 outputs the excitation voltage Vi.

[0087] Preferably, the amplification module 102 includes a comparator U2, a resistor R1, a resistor R2 and a resistor R3. The output end of the comparator U1 is connected to the negative end of the comparator U2 via the resistor R2, the negative end of the comparator U2 is connected to the output end of the comparator U2 via the resistor R3, the positive end of the comparator U2 is grounded via the resistor R1, and the comparator U2 outputs a reference voltage VR.

[0088] It should be noted that the control amount conversion module 103 and the method conversion DAC 104 can use commercially available mature chips to complete the corresponding functions, which will not be described in detail here.

[0089] Preferably, the excitation voltage Vi converted by the current / voltage conversion module 101 is: V i =I i R0;

[0090] After amplification by the amplification module 102, the reference voltage VR is:

[0091] The amplification factor K of the amplification module 102 is R3 / R2 .

[0092] Preferably, the resistor R2 is set to 1KΩ, and the resistor R3 is set to 20KΩ, then the amplification factor K of the amplification module 102 is 20, and the reference voltage VR is:

[0093]

[0094] Figure 3 The present invention also provides a method for simulating platinum thermal resistor signals, comprising the steps of:

[0095] S1, generates an excitation current Ii, and converts the excitation current Ii into an excitation voltage Vi;

[0096] S2, based on the simulated different types of platinum thermal resistors, amplify the excitation voltage Vi to obtain a reference voltage VR; based on the desired simulated temperature T and according to a preset resolution, calculate the control amount C. Different types of platinum thermal resistors can be PT100, PT200 or PT1000, etc. The amplification factor of the amplified excitation voltage Vi is determined according to the type of the platinum thermal resistor.

[0097] S3, calculating the output voltage Vo of the simulated platinum thermal resistor according to the input control quantity C, the preset resolution and the reference voltage VR.

[0098] The present invention provides a platinum thermistor signal simulation method. By setting an excitation current Ii and a desired simulation temperature T, the output voltage Vo of the platinum thermistor can be simulated according to the control quantity C obtained by calculation, thereby realizing signal simulation of different types of platinum thermistors. According to a preset resolution, the accuracy of platinum thermistor signal simulation can be improved.

[0099] Preferably, if the simulation method is used to simulate a PT100 thermal resistor, the sampling resistor used in step S1 is R0, the amplification factor of the excitation voltage Vi in step S2 is K, and the configuration resolution is 16 Bit;

[0100] Then the excitation voltage Vi is: V i =I i ·R0 formula 1;

[0101] The reference voltage VR is: V R =K·V i =K·I i ·R0 formula 2;

[0102] The output voltage Vo is:

[0103]

[0104] According to formula 1-3, the voltage difference VD between the output voltage Vo and the excitation voltage Vi is:

[0105]

[0106] The resistance value RT of the simulated platinum thermal resistor is:

[0107]

[0108] Get the function of resistance value RT and temperature T:

[0109]

[0110] Among them, A, B, C and R100 are known constants. Based on the sampling resistor R0 and the amplification factor K, the control quantity C is obtained by solving formula 5-6.

[0111] It is easy to understand that according to the type of platinum resistance to be simulated, the amplification factor and set resolution of the amplifier module 102 are determined, and the control quantity C can be calculated based on the set temperature T, excitation current Ii and resolution to ensure that the final output voltage Vo meets the simulation requirements.

[0112] Preferably, when simulating the platinum thermal resistor PT100, the sampling resistor R0 is set to 20Ω, the amplification factor K of the amplifier module 102 is set to 20, and when the temperature T is between -200°C and 850°C, the simulation range of the resistance value RT of the simulated platinum thermal resistor PT100 is 20Ω to 400Ω, and the actual range is approximately between 18.4Ω and 390.5Ω.

[0113] It will be apparent to those skilled in the art that various modifications and variations may be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention covers modifications and variations of the present invention that fall within the scope of the appended claims and their equivalent technical solutions.

Claims

1. A platinum thermal resistance signal simulation circuit, comprising: A current / voltage conversion module, used for converting the input excitation current Ii into an excitation voltage Vi; an amplifying module, amplifying the excitation voltage Vi based on the simulated different types of platinum thermal resistors, and outputting a reference voltage VR; A control quantity conversion module, used for calculating the control quantity C based on the desired simulated temperature T and according to a preset resolution; The method conversion DAC is used to calculate the output voltage Vo according to the input control quantity C, the preset resolution and the reference voltage VR.

2. The platinum thermal resistance signal simulation circuit according to claim 1, characterized in that: If the analog simulation circuit is used to simulate a PT100 thermal resistor, the sampling resistor of the current / voltage conversion module is assumed to be R0, the amplification factor of the excitation voltage Vi amplified by the amplification module is K, and the resolution is 16 Bit; Then the excitation voltage Vi is: V i =I i ·R0 formula 1; The reference voltage VR is: V R =K·V i =K·I i ·R0 formula 2; The output voltage Vo is converted to DAC by the method: According to formula 1-3, the voltage difference VD between the output voltage Vo and the excitation voltage Vi is: The resistance value RT of the simulated platinum thermal resistor is: Get the function of resistance value RT and temperature T: Among them, A, B, C and R100 are known constants. Based on the sampling resistor R0 and the amplification factor K, the control quantity C is obtained by solving formula 5-6.

3. The platinum thermal resistance signal simulation circuit as described in claim 2, characterized in that: The sampling resistor R0 is 20Ω, the amplification factor K of the amplification module is 20, and the temperature T is between -200° C. and 850° C., then the simulation range of the resistance value RT is 20Ω to 400Ω.

4. The platinum thermal resistance signal simulation circuit according to claim 1, characterized in that: The current / voltage conversion module includes a sampling resistor R0 and a comparator U1, the positive input end of the comparator U1 is the input end of the excitation current Ii, the positive input end of the comparator U1 is grounded through the sampling resistor R0, the negative input end of the comparator U1 is connected to the output end, and the comparator U1 outputs the excitation voltage Vi.

5. The platinum thermal resistance signal simulation circuit as claimed in claim 4, characterized in that: The amplification module includes a comparator U2, a resistor R1, a resistor R2 and a resistor R3. The output end of the comparator U1 is connected to the negative end of the comparator U2 via the resistor R2, the negative end of the comparator U2 is connected to the output end of the comparator U2 via the resistor R3, the positive end of the comparator U2 is grounded through the resistor R1, and the comparator U2 outputs a reference voltage VR.

6. The platinum thermal resistance signal simulation circuit according to claim 5, characterized in that: The excitation voltage Vi converted by the current / voltage conversion module is: V i =I i R0; After amplification by the amplification module, the reference voltage VR is:

7. The platinum thermal resistance signal simulation circuit according to claim 6, characterized in that: The resistor R2 is 1KΩ, the resistor R3 is 20KΩ, and the reference voltage VR is:

8. A platinum thermal resistance signal simulation method, comprising the steps of: S1, generating an excitation current Ii, and converting the excitation current Ii into an excitation voltage Vi; S2, amplifying the excitation voltage Vi based on the simulated different types of platinum thermal resistors to obtain a reference voltage VR; calculating the control amount C based on the desired simulated temperature T and according to a preset resolution; S3, calculating and simulating the output voltage Vo of the platinum thermal resistor according to the input control quantity C, the preset resolution and the reference voltage VR.

9. The platinum thermal resistance signal simulation method according to claim 8, characterized in that: If used to simulate a PT100 thermal resistor, the sampling resistor used in step S1 is assumed to be R0, the amplification factor of the excitation voltage Vi in step S2 is K, and the resolution is 16 Bit; Then the excitation voltage Vi is: V i =I i ·R0 formula 1; The reference voltage VR is: V R =K·V i =K·I i ·R0 formula 2; The output voltage Vo is: According to formula 1-3, the voltage difference VD between the output voltage Vo and the excitation voltage Vi is: The resistance value RT of the simulated platinum thermal resistor is: Get the function of resistance value RT and temperature T: Among them, A, B, C and R100 are known constants. Based on the sampling resistor R0 and the amplification factor K, the control quantity C is obtained by solving formula 5-6.

10. The platinum thermal resistance signal simulation method according to claim 9, characterized in that: The sampling resistor R0 is 20Ω, the amplification factor K of the amplification module is 20, and the temperature T is between -200° C. and 850° C., then the simulation range of the resistance value RT is 20Ω to 400Ω.

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