Analog signal acquisition circuit design method, acquisition method and device

Abstract

This patent discloses a design method, acquisition method and device for analog signal acquisition circuit, which belongs to the field of analog signal acquisition. The technical solution provided by this patent can customize the range and preset the measurement accuracy. Without replacing the high-precision analog signal board, it can meet the range of analog signals output by different devices and the different requirements of these devices for measurement accuracy, while ensuring high-precision measurement. The main technical scheme of the present invention is: setting at least one range gear; setting a reference voltage corresponding to the range gear; using the reference voltage to customize the range; using the reference voltage to pre-set the measurement accuracy of the analog signal to be measured. Switch the analog signal to be measured to the appropriate range gear and match the corresponding reference voltage; collect the analog signal to be measured and output the displayed measurement value.

Description

Technical Field

[0001] The present invention is applicable to the technical field of analog signal acquisition, and in particular relates to an analog signal design method, an acquisition method and a device. Background Art

[0002] In existing analog signal acquisition, resolution and range are two common indicators commonly used to measure the performance of the acquisition system.

[0003] First of all, the resolution determines the measurement accuracy of the acquisition system. The analog signal acquisition board will provide its own analog-to-digital conversion bit number n. Assuming that the reference voltage is Vref, without considering other disturbance parameters such as bit error rate, the resolution of the acquisition board can be calculated based on the conversion bit number and reference voltage value of the acquisition board. The problem with this measurement system is that when the measured signal is small, an op amp is needed to increase the signal amplitude, otherwise the measurement error will be very high. For example, for a first-level measuring instrument, it is necessary to ensure that the measurement accuracy does not exceed 0.1% in the entire measurement range. The resolution of a 10-bit analog signal acquisition board meets the accuracy requirements. Assuming that the measured signal is 2.5V, when the measured signal drifts upward by 0.1%, that is, when the signal becomes 2.5025V, the first-level meter should distinguish this change, but in fact, the minimum resolution of the acquisition board is 5mV, and it is impossible to distinguish the signal fluctuation of 2.5mV. This leads to the fact that the acquisition board that can theoretically achieve 0.1% accuracy is actually insufficient in resolution. At present, in order to make up for this shortcoming, the commonly used means is to use an acquisition board with a higher conversion bit number to leave enough resolution margin. However, acquisition boards with high conversion bit numbers are expensive, and this will greatly increase the cost. The root cause of this problem is that the reference voltage of ordinary analog signal acquisition circuits is a fixed value, so the resolution will not change with the measurement to be measured.

[0004] The second is the range, which is mainly restricted by two conditions: one is that the reference voltage of the acquisition board will be divided into multiple levels after being input into the board. When the analog signal input value is compared with the value of the reference voltage after voltage division, the voltage amplitude of the analog signal to be measured must not be higher than the reference voltage. The other is that when the input voltage amplitude is too small, the accuracy level of the measurement circuit will decrease, so the lower limit of the analog signal to be measured is also limited. Through the above two conditions, the accurate sampling interval of the ordinary analog signal acquisition circuit can be obtained, and this interval is called the range.

[0005] Common analog signal acquisition conditioning circuits in the prior art mostly use voltage divider circuits to meet the measurement range requirements, or use manual range switching methods. It is impossible to customize the range and control the measurement accuracy. When the measurement accuracy requirements are different, it is necessary to replace analog signal acquisition boards with different accuracies, which increases labor costs and the cost of high-precision boards.

[0006] Airborne avionics systems are composed of multiple functional units, among which there are a variety of analog devices. The analog signal output value ranges of these devices are different, and the requirements for measurement accuracy are also different. Therefore, it is necessary to collect analog signals of different ranges and accuracy in the avionics integrated test system. The analog signal acquisition board has a certain range, and an analog signal board can only meet one measurement accuracy. The higher the accuracy of the analog board, the higher the cost. Therefore, an analog signal acquisition circuit is needed that can customize the range and preset the measurement accuracy. Without replacing the high-precision analog signal board, it can meet the analog signal output value range of different analog devices and the different requirements of these devices for measurement accuracy, while ensuring high-precision measurement. Summary of the invention

[0007] The present invention provides an analog signal acquisition method and device, which are used to solve the problems of the existing analog signal acquisition method, such as fixed resolution, restricted range, high cost of using high-precision analog signal acquisition board, and poor voltage divider circuit effect.

[0008] An embodiment of the present invention provides a method for designing an analog signal acquisition circuit, the method comprising:

[0009] Set at least one range gear;

[0010] Set a reference voltage corresponding to the range position.

[0011] The setting factors of the range gear include the historical measurement values ​​of the analog signal output by the device.

[0012] The reference voltage is used to customize the range. The change of the range is achieved by switching the reference voltage, and the reduction of the range is achieved by increasing the reference voltage. When the range becomes smaller, a higher precision measurement accuracy can be achieved. The corresponding reference voltage can be set according to the measurement accuracy requirements of different devices to obtain the required measurement accuracy.

[0013] The result of the custom range is obtained by subtracting the reference voltage corresponding to the appropriate range from the appropriate range of the analog signal to be measured.

[0014] The reference voltage is used to pre-set the measurement accuracy of the analog signal to be measured. As mentioned above, the corresponding reference voltage can be set according to the measurement accuracy requirements of different devices to obtain the required measurement accuracy.

[0015] Calculate the preset measurement accuracy of the analog signal to be measured according to the following formula:

[0016]

[0017] Wherein, V is the appropriate range of the analog signal to be measured; Vref is the reference voltage corresponding to the appropriate range; and n is the accuracy of the analog signal acquisition board.

[0018] The setting factors of the corresponding reference voltage include the measurement accuracy requirement of the device and / or the set range gear and / or the accuracy of the analog signal acquisition board. The reference voltage gear that meets the measurement accuracy requirements of different devices can be set.

[0019] The device includes avionics equipment. Different devices in the avionics system have different requirements for measurement accuracy of analog signals outputted by them. The corresponding reference voltage Vref can be increased and set to a high-precision gear, and the analog signal to be measured can be conditioned to the range V-Vref corresponding to the corresponding reference voltage.

[0020] An embodiment of the present invention provides an analog signal acquisition method, the method comprising:

[0021] Switch the analog signal to be measured to the appropriate range and match the corresponding reference voltage;

[0022] Collect the analog signal to be tested and output the measured value.

[0023] The switching to the appropriate range gear includes switching the range gear in descending order to the appropriate range gear of the input analog signal to be measured; the appropriate range gear ensures the safety of the acquisition circuit; the appropriate range gear minus the corresponding reference voltage is the custom range; the analog signal to be measured collected by the appropriate range gear and its corresponding reference voltage and the output display measurement value can meet the measurement accuracy requirements of the device. It can be seen that this acquisition method can customize the range and control the measurement accuracy at the same time.

[0024] The corresponding reference voltage corresponds to the appropriate range gear one by one, and the corresponding reference voltage is matched when switching to the appropriate range gear. This process completes the confirmation of the analog signal measurement range, and at the same time completes the conditioning of the input analog signal to be measured. The acquisition board collects the input analog signal to be measured, and realizes high-precision measurement with preset accuracy in a custom range.

[0025] The device includes avionics equipment. Different devices in the avionics system have different requirements for measurement accuracy of analog signals outputted by them. The corresponding reference voltage Vref can be increased and set to a high-precision gear, and the analog signal to be measured can be conditioned to the range V-Vref corresponding to the corresponding reference voltage.

[0026] An embodiment of the present invention provides an analog signal acquisition device, comprising:

[0027] The analog signal input unit to be tested is used to input the analog signal to be tested;

[0028] The analog signal conditioning unit is used to switch the analog signal to be measured to a suitable range and match the corresponding reference voltage;

[0029] An analog signal acquisition unit, used for acquiring an analog signal to be tested;

[0030] The output display unit is used to output and display the measured value of the analog signal to be measured.

[0031] The accuracy of the measured value is obtained according to the following formula:

[0032]

[0033] Wherein, V is the appropriate range of the analog signal to be measured; Vref is the reference voltage corresponding to the appropriate range; and n is the accuracy of the analog signal acquisition board.

[0034] The analog signal conditioning unit is further used for:

[0035] Switch the range gear from large to small to the appropriate range gear for the input analog signal to be measured;

[0036] Using the corresponding reference voltage to customize the range to condition the analog signal to be measured;

[0037] The corresponding reference voltage is used to preset the measurement accuracy of the analog signal to be measured.

[0038] The analog signal acquisition unit is further used for:

[0039] The analog signal acquisition board is used to acquire the analog signal to be tested.

[0040] The beneficial effects of the present invention are:

[0041] The analog signal acquisition circuit design method provided in the embodiment of the present invention is expandable. The analog signal acquisition circuit designed according to the design method provided in the present invention can be suitable for the measurement accuracy requirements of analog devices in different application scenarios. For example, when the analog signal measurement requires higher measurement accuracy, a higher reference voltage can be set according to the same principle, thereby setting the reference voltage for more channels.

[0042] The analog signal acquisition method provided in the embodiment of the present invention adopts a switching reference voltage conditioning method in the acquisition and measurement of analog signals, replacing the voltage divider circuit conditioning method, so as to condition the analog signals to be measured in different ranges within the measuring range of the analog signal acquisition board, and can adapt to the accuracy of different acquisition boards, thereby reducing the cost of analog acquisition boards caused by high-precision requirements.

[0043] The embodiment of the present invention adopts a conditioning method of switching reference voltage to measure analog signals with different accuracy requirements, adapt to different analog signal ranges and measurement accuracies, improve the measurement accuracy when measuring under different ranges, and achieve high-precision measurement.

[0044] The analog signal acquisition circuit design method provided in the embodiment of the present invention can set different reference voltages according to the different requirements of different devices for analog signal measurement accuracy. The analog signal acquisition method provided in the embodiment of the present invention can switch different reference voltages according to the different requirements of different devices for analog signal measurement accuracy to obtain the required measurement accuracy.

[0045] For example, different devices in an avionics system have different requirements for the measurement accuracy of analog signals, so the analog signal acquisition circuit design method, acquisition method and device provided in the embodiments of the present invention are particularly suitable for the field of avionics, which can not only ensure high-precision measurement but also control costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0047] Figure 1 is a flow chart of an analog signal acquisition method in one embodiment of the present invention;

[0048] Figure 2 is a schematic diagram of an analog signal acquisition circuit in Embodiment 1 of the present invention;

[0049] Figure 3 is a flow chart of the analog circuit acquisition method in Embodiment 1 of the present invention;

[0050] Figure 4 It is a block diagram of an analog signal acquisition device in one embodiment of the present invention. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] The most critical invention point of the present invention is that the measurement range of the analog signal to be measured is customized and the measurement accuracy of the analog signal to be measured is pre-set by switching the appropriate range gear to match the corresponding reference voltage, which is essentially switching the reference voltage.

[0053] Figure 1 The flowchart of the analog signal acquisition method according to one embodiment of the present invention is as follows. The acquisition method according to the embodiment includes:

[0054] Input the analog signal to be tested;

[0055] Switching the analog signal to be measured to a suitable range gear; said switching to a suitable range gear includes switching the range gear in order from large to small to a range gear suitable for the input analog signal to be measured, and the analog signal to be measured collected by said suitable range gear and the measured value output and displayed meet the measurement accuracy requirements of the equipment;

[0056] Matching a corresponding reference voltage; the corresponding reference voltage corresponds to the appropriate range gear one by one, and the corresponding reference voltage is matched while switching to the appropriate range gear;

[0057] Collect the analog signal to be tested;

[0058] The output displays the measured value.

[0059] Figure 2 is a schematic diagram of an analog signal acquisition circuit in Embodiment 1 of the present invention; Figure 2 At the same time, the process of the analog signal acquisition circuit design method in Example 1 of the present invention is shown. The design method in Example 1 includes:

[0060] Set three range gears V1, V2, V3; the three range gears V1 <V2<V3;

[0061] Set three reference voltages Vref1, Vref2, and Vref3 corresponding to the three range positions; <Vref1<Vref2<Vref3;

[0062] Defining a measuring range by using the reference voltage;

[0063] The result of the custom range is obtained by subtracting the reference voltage corresponding to the appropriate range gear from the appropriate range gear of the analog signal to be measured; the results of the custom range in Example 1 are V1-Vref1, V2-Vref2, V3-Vref3;

[0064] Presetting the measurement accuracy of the analog signal to be measured by using the reference voltage;

[0065] Calculate the preset measurement accuracy of the analog signal to be measured according to the following formula:

[0066]

[0067] Where V is the appropriate range of the analog signal to be measured; Vref is the reference voltage corresponding to the appropriate range; n is the accuracy of the analog signal acquisition board;

[0068] The analog signal acquisition board of Example 1 has an accuracy of 8 bits and a range of V;

[0069] The measurement accuracy when the reference voltage reference ground is zero is

[0070] When the reference voltage is 0, the sampling accuracy is

[0071] When the reference voltage is Vref1, without replacing the 8-bit analog signal acquisition board, the sampling accuracy is

[0072] When the reference voltage is Vref2, without replacing the 8-bit analog signal acquisition board, the sampling accuracy is

[0073] When the reference voltage is Vref3, without replacing the 8-bit analog signal acquisition board, the sampling accuracy is

[0074] Therefore, the sampling accuracy after matching the corresponding reference voltage is higher than

[0075] Example 1 is illustrated by setting three measuring ranges V1, V2, and V3, and the reference voltages Vref1, Vref2, and Vref3 corresponding to the three measuring ranges. When setting specific measuring ranges, the measuring ranges can be set according to the measurement accuracy requirements of the analog signal. The corresponding reference voltages can also be set according to the measurement accuracy requirements of the analog signal to obtain the required measurement accuracy, thereby realizing the use of an analog signal acquisition board to collect analog signals of multiple ranges and multiple measurement accuracies.

[0076] This method for designing an analog signal acquisition circuit provides an expandable analog signal acquisition and measurement circuit. Different range gears and different reference voltages can be set according to different measurement requirements in different scenarios to condition the analog signal to meet the requirements of high measurement accuracy. For example, when a higher-precision analog signal measurement value is needed, a higher reference voltage can be set according to the same principle to obtain the required measurement accuracy.

[0077] Figure 3 It is a schematic flowchart of the analog circuit acquisition method in Embodiment 1 of the present invention;

[0078] The accuracy of the analog signal acquisition board in Embodiment 1 is 8 bits, the range is V, and the analog signal to be measured is U.

[0079] The acquisition method in Embodiment 1 includes:

[0080] Input the analog signal U to be measured and select a suitable range gear from large to small;

[0081] When the range gear is set to the maximum range gear V3 and V2 ≤ U ≤ V3, then select the V3 range gear and match Vref3 as the corresponding reference voltage. The measurement accuracy at this time is At this time, the voltage value is within the acquisition range of the analog signal acquisition board, and a higher-precision measurement value is obtained;

[0082] When the range gear is set to the range gear V2 and V1 ≤ U < V2, then select the V2 range gear and match Vref2 as the corresponding reference voltage. The measurement accuracy at this time is At this time, the voltage value is within the acquisition range of the analog signal acquisition board, and a higher-precision measurement value is obtained;

[0083] When the range gear is set to the range gear V3 and V0 ≤ U < V1, then select the V1 range gear and match Vref1 as the corresponding reference voltage. The measurement accuracy at this time is At this time, the voltage value is within the acquisition range of the analog signal acquisition board, and a higher-precision measurement value is obtained.

[0084] The order of switching range gears from large to small is adopted, and it will start comparing with U from the large range in turn until the appropriate range gear is switched and the corresponding reference voltage is matched. The custom range is realized by switching the reference voltage while switching the range gear. This process completes the conditioning of the analog signal to be measured, and through this conditioning process, the input analog signal to be measured can be adapted to the measurement range of the analog signal acquisition board. Since the switched reference voltages are all larger than the zero value of the reference ground in the traditional method, the reference voltage is increased compared with the reference ground. Narrowing the range is achieved by increasing the reference voltage. When the range is narrowed, a higher measurement accuracy can be achieved.

[0085] The analog signal acquisition circuit design method and acquisition method provided in the embodiments of the present invention can be applied to the analog signal acquisition and measurement of avionics systems. Different devices in the avionics system have different requirements for the measurement accuracy of analog signals output. Therefore, for different devices, range gears and reference voltages that meet their measurement accuracy requirements can be set. When measuring analog signals, by setting the reference voltage to a high-precision gear, the analog quantity to be measured is adjusted to a range customized by the reference voltage, and the analog signal U to be measured is input. U is compared with a larger range, a smaller range, and a small range gear in order from large to small, U is switched to a suitable range gear, and the corresponding reference voltage is matched at the same time, and U is adjusted to a customized range. The analog signal acquisition board collects U, thereby realizing high-precision measurement of variable range and variable accuracy.

[0086] The comparison between the measurement values ​​collected by the analog signal collection method provided in Example 1 of the present invention and the measurement values ​​collected by the traditional collection method is as follows:

[0087] Analog input to be measured Switching reference voltage Do not switch reference voltage 0.2V 0.201V 0.201V 2.5V 2.503V 2.50V 21.5V 21.513V 21.5V

[0088] It can be seen from the measurement value results that the analog signal acquisition circuit design method and acquisition method provided in the embodiments of the present invention can realize a custom range by switching the range gear to match the corresponding reference voltage conditioning means, thereby pre-setting the analog signal measurement accuracy and achieving high-precision measurement.

[0089] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0090] In one embodiment, an analog signal acquisition device is provided, and the analog signal acquisition device corresponds one-to-one to the analog signal acquisition method in the above embodiment.

[0091] The analog signal input unit to be measured inputs the analog signal U to be measured into the analog signal acquisition device provided by the embodiment of the present invention, and then reaches the analog signal conditioning unit, in which U is switched from a large range to a small range in order from large to small, switched to a suitable range gear, and matched with a corresponding reference voltage, to complete the custom measurement range, and at the same time complete the conditioning of the analog signal to be measured. Then it reaches the analog acquisition unit, completes the acquisition of the analog signal to be measured, and finally reaches the output display unit, completes the display of the measured value of the analog signal to be measured.

[0092] For other specific limitations on the analog signal acquisition device, please refer to the above limitations on the analog signal acquisition method, which will not be repeated here. Each unit in the above analog signal acquisition device can be fully or partially implemented by software, hardware or a combination thereof.

[0093] A person skilled in the art can understand the implementation of all or part of the processes in the above-mentioned embodiments. A person skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In practical applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. The above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them. Although the present invention is described in detail with reference to the above-mentioned embodiments, a person skilled in the art should understand that the technical solutions described in the above-mentioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A method for designing an analog signal acquisition circuit, characterized in that: The method comprises: Set at least one range gear; Setting a reference voltage corresponding to the range position; The reference voltage is used to define a custom range, wherein the result of the custom range is obtained by subtracting the reference voltage corresponding to the appropriate range from the appropriate range of the analog signal to be measured; The reference voltage is used to preset the measurement accuracy of the analog signal to be measured, and the preset measurement accuracy of the analog signal to be measured is calculated according to the following formula: Wherein, V is the appropriate range of the analog signal to be measured; Vref is the reference voltage corresponding to the appropriate range; and n is the accuracy of the analog signal acquisition board.

2. The analog signal acquisition circuit design method according to claim 1, characterized in that: The setting factors of the corresponding reference voltage include the measurement accuracy requirement of the device and / or the set range gear and / or the accuracy of the analog signal acquisition board.

3. A method for collecting analog signals, characterized in that: The method comprises: Switch the analog signal to be measured to the appropriate range and match the corresponding reference voltage; the measurement accuracy of the analog signal to be measured is Where V is the appropriate range of the analog signal to be measured; Vref is the reference voltage corresponding to the appropriate range; n is the accuracy of the analog signal acquisition board; Collect the analog signal to be tested and output the measured value.

4. The analog signal acquisition method according to claim 3, characterized in that: The switching to a suitable range gear comprises switching the range gear in a descending order to a suitable range gear of the input analog signal to be measured.

5. The analog signal acquisition method according to claim 3, characterized in that: The corresponding reference voltage corresponds to the appropriate range gear one by one, and the corresponding reference voltage is matched while switching to the appropriate range gear.

6. An analog signal acquisition device, characterized in that: include: The analog signal input unit to be tested is used to input the analog signal to be tested; The analog signal conditioning unit is used to switch the analog signal to be measured to a suitable range and match the corresponding reference voltage; An analog signal acquisition unit, used for acquiring an analog signal to be tested; An output display unit, used for outputting and displaying the measured value of the analog signal to be measured; The accuracy of the measured value is obtained according to the following formula: Wherein, V is the appropriate range of the analog signal to be measured; Vref is the reference voltage corresponding to the appropriate range; and n is the accuracy of the analog signal acquisition board.

7. The analog signal acquisition device according to claim 6, characterized in that: The analog signal conditioning unit is further used for: Switch the range gear from large to small to the appropriate range gear for the input analog signal to be measured; Using the corresponding reference voltage to customize the range to condition the analog signal to be measured; Presetting the measurement accuracy of the analog signal to be measured by using the corresponding reference voltage; The analog signal acquisition unit is further used to: use an analog signal acquisition board to acquire the analog signal to be tested.

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