A current-to-frequency conversion device and method based on digital compensation

Abstract

This invention provides a current-frequency conversion device and method based on digital compensation. The device includes an integrating circuit, a threshold circuit, an FPGA module, a switching circuit, a constant current source module, a DAC compensation circuit, and a temperature detection module. The integrating circuit integrates the input current to generate an integrated voltage signal. The threshold circuit compares the integrated voltage signal with a threshold voltage and outputs a level signal. The temperature detection module collects temperature data from the constant current source module. The FPGA module outputs a frequency signal based on the level signal, receives the temperature data, calculates the compensation current value based on the temperature data and the output value of the frequency signal, generates a compensation control signal, and sends it to the DAC compensation circuit. The DAC compensation circuit controls the constant current source module to output a corresponding compensation current to the integrating circuit based on the compensation control signal. The switching circuit controls the on / off state of the constant current source module. This device can effectively provide accurate compensation.

Description

Technical Field

[0001] This invention relates to the field of signal conversion technology, and in particular to a current-frequency conversion device and method based on digital compensation. Background Technology

[0002] Current-to-frequency conversion circuits are increasingly widely used in inertial navigation. Their main function is to convert current signals into corresponding frequency signals to output pulses. Traditional compensation methods involve soldering temperature-compensated current sources and adjusting resistors to change the output current of the constant current source, thereby adjusting the scaling factor. However, this method can only establish a linear model based on the tested temperature point, resulting in a simple compensation method but poor compensation effectiveness. Summary of the Invention

[0003] This invention provides a current-frequency conversion device and method based on digital compensation to solve the problem of poor compensation effect in the current-frequency conversion circuit in the prior art.

[0004] A current-frequency conversion device based on digital compensation includes an integrating circuit, a threshold circuit, an FPGA module, a switching circuit, a constant current source module, a DAC compensation circuit, and a temperature detection module.

[0005] The integrating circuit is used to integrate the input current to generate an integrated voltage signal; the threshold circuit is used to compare the integrated voltage signal with a threshold voltage and output a level signal; the temperature detection module is used to collect the temperature data of the constant current source module.

[0006] The FPGA module is used to output a frequency signal according to the level signal, receive the temperature data, calculate the compensation current value according to the temperature data and the output value of the frequency signal, generate a compensation control signal and send it to the DAC compensation circuit. The DAC compensation circuit is used to control the constant current source module to output a corresponding compensation current to the integrator circuit according to the compensation control signal. The switching circuit is used to control the on and off of the constant current source module.

[0007] Furthermore, the threshold circuit is used to compare the integrated voltage signal with a preset threshold voltage. When the integrated voltage signal is less than the threshold voltage, a low-level signal is output; when the integrated voltage signal is higher than or equal to the threshold voltage, a high-level signal is output.

[0008] Furthermore, when the threshold circuit outputs a low-level signal, the FPGA module stops outputting frequency signals.

[0009] Furthermore, when the threshold circuit outputs a high-level signal, the FPGA module outputs a frequency signal.

[0010] Furthermore, when the threshold circuit outputs a high-level signal, the FPGA module controls the temperature detection module to collect the temperature data of the constant current source module according to a preset time interval, and calculates the compensation current value based on the output value of the corresponding frequency signal at each temperature.

[0011] Furthermore, the compensation current value is calculated using the following formula:

[0012]

[0013] Where ΔI is the compensation current value, K ω K represents the frequency value of the full-scale current output. n For at temperature T n The output value of the frequency signal at room temperature, K0 is the output reference value of the frequency signal at room temperature, and η is the utilization rate of the constant current source module.

[0014] Furthermore, when the temperature T n The output value K of the frequency signal below n The compensation current is positive when it is greater than or equal to the output reference value K0 of the frequency signal at room temperature; when the temperature T n The output value K of the frequency signal below n When the output reference value K0 of the frequency signal at room temperature is less than the value of the frequency signal at room temperature, the compensation current is negative.

[0015] A current-frequency conversion method based on digital compensation using the above-mentioned device includes:

[0016] The input current is integrated by an integrating circuit to generate an integrated voltage signal;

[0017] A threshold circuit is used to compare the integrated voltage signal with a threshold voltage and output a level signal.

[0018] Temperature data from the constant current source module is collected via the temperature detection module.

[0019] The FPGA module outputs a frequency signal based on the level signal, receives the temperature data, calculates the compensation current value based on the temperature data and the output value of the frequency signal, generates a compensation control signal and sends it to the DAC compensation circuit. The DAC compensation circuit is used to control the constant current source module to output the corresponding compensation current to the integrator circuit according to the compensation control signal.

[0020] The constant current source module is switched on and off via a switching circuit.

[0021] Furthermore, a threshold circuit is used to compare the integrated voltage signal with a threshold voltage, and the output level signal includes:

[0022] The threshold circuit compares the integrated voltage signal with a preset threshold voltage. When the integrated voltage signal is less than the threshold voltage, it outputs a low-level signal; when the integrated voltage signal is higher than or equal to the threshold voltage, it outputs a high-level signal.

[0023] Furthermore, when the threshold circuit outputs a low-level signal, the FPGA module stops outputting the frequency signal;

[0024] When the threshold circuit outputs a high-level signal, the FPGA module outputs a frequency signal. The FPGA module controls the temperature detection module to collect the temperature data of the constant current source module according to a preset time interval, and calculates the compensation current value based on the output value of the corresponding frequency signal at each temperature.

[0025] The current-frequency conversion device and method based on digital compensation provided by the present invention have at least the following beneficial effects:

[0026] By establishing the relationship between temperature and frequency signal output values, a DAC compensation circuit is introduced to control a constant current source to provide compensation current, thereby improving the accuracy of compensation and thus improving the accuracy and reliability of frequency signal conversion. The structure is simple, reducing hardware costs and the overall size of the device. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of one embodiment of the current-frequency conversion device based on digital compensation provided by the present invention.

[0028] Figure 2 This is a flowchart of one embodiment of the current-frequency conversion method based on digital compensation provided by the present invention. Detailed Implementation

[0029] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0030] refer to Figure 1 In some embodiments, a current-frequency conversion device based on digital compensation is provided, including an integrating circuit 1, a threshold circuit 2, an FPGA module 3, a switching circuit 4, a constant current source module 5, a DAC compensation circuit 6, and a temperature detection module 7.

[0031] Integrating circuit 1 is used to integrate the input current to generate an integrated voltage signal; threshold circuit 2 is used to compare the integrated voltage signal with a threshold voltage and output a level signal; temperature detection module 7 is used to collect the temperature data of the constant current source module.

[0032] FPGA module 3 is used to output a frequency signal according to the level signal, receive the temperature data, calculate the compensation current value according to the temperature data and the output value of the frequency signal, generate a compensation control signal and send it to DAC compensation circuit 6. DAC compensation circuit 6 is used to control the constant current source module 5 to output the corresponding compensation current to the integrator circuit according to the compensation control signal. Switching circuit 4 is used to control the on and off of constant current source module 5.

[0033] Specifically, refer to Figure 1 The integrating circuit 1 is connected to the threshold circuit 2, the threshold circuit 2 is connected to the FPGA module 3, the switching circuit 4 is connected between the constant current source module 5 and the FPGA module 3, the DAC compensation circuit 6 is connected between the FPGA module 3 and the constant current source module 5, and the temperature detection module 7 is connected to the constant current source module 5 and the FPGA module 3.

[0034] Furthermore, the threshold circuit 2 is used to compare the integrated voltage signal with a preset threshold voltage. When the integrated voltage signal is less than the threshold voltage, a low-level signal is output; when the integrated voltage signal is higher than or equal to the threshold voltage, a high-level signal is output.

[0035] Furthermore, when the threshold circuit 2 outputs a low-level signal, the FPGA module 3 stops outputting the frequency signal. When the threshold circuit 2 outputs a high-level signal, the FPGA module 3 outputs the frequency signal.

[0036] When the threshold circuit 2 outputs a high-level signal, the feedback phase begins. The FPGA module 3 controls the temperature detection module 7 to collect temperature data from the constant current source module 5 according to a preset time interval. Based on the output value of the corresponding frequency signal at each temperature, the compensation current value is calculated. Specifically, the collected temperature data at the preset time intervals are T1, T2, T3, T4, T5…T… n Meanwhile, the output values ​​of the frequency signals at each temperature point are K1, K2, K3, K4, K5...K n The output value of the frequency signal is the scaling factor. Generally speaking, the scaling factor at room temperature is taken as the reference K0 to adjust the scaling factor value at various temperatures. The compensation is essentially an adjustment of the scaling factor, which is achieved by adjusting the magnitude of the feedback current output by the constant current source module.

[0037] The compensation current value is calculated using the following formula:

[0038]

[0039] Where ΔI is the compensation current value, K ω K represents the frequency value of the full-scale current output. n For at temperature T nThe output value of the frequency signal at room temperature, K0 is the output reference value of the frequency signal at room temperature, and η is the utilization rate of the constant current source module.

[0040] Furthermore, the sign of the compensation current depends on the relationship between the output value of the frequency signal and the reference value at each temperature point. When the temperature T... n The output value K of the frequency signal below n The compensation current is positive when it is greater than or equal to the output reference value K0 of the frequency signal at room temperature; when the temperature T n The output value K of the frequency signal below n When the output reference value K0 of the frequency signal at room temperature is less than the value of the frequency signal at room temperature, the compensation current is negative.

[0041] The apparatus provided in the above embodiments has at least the following beneficial effects:

[0042] By establishing the relationship between temperature and frequency signal output values, a DAC compensation circuit is introduced to control a constant current source to provide compensation current, thereby improving the accuracy of compensation and thus improving the accuracy and reliability of frequency signal conversion. The structure is simple, reducing hardware costs and the overall size of the device.

[0043] In some embodiments, reference Figure 2 A current-frequency conversion method based on digital compensation using the above-mentioned device is provided, comprising:

[0044] S1. The input current is integrated through an integrating circuit to generate an integrated voltage signal;

[0045] S2. A threshold circuit is used to compare the integrated voltage signal with a threshold voltage and output a level signal.

[0046] S3. Collect temperature data from the constant current source module through the temperature detection module;

[0047] S4. The FPGA module outputs a frequency signal according to the level signal, receives the temperature data, calculates the compensation current value according to the temperature data and the output value of the frequency signal, generates a compensation control signal and sends it to the DAC compensation circuit. The DAC compensation circuit is used to control the constant current source module to output the corresponding compensation current to the integrator circuit according to the compensation control signal.

[0048] S5. The constant current source module is switched on and off via a switching circuit.

[0049] Specifically, in step S2, a threshold circuit is used to compare the integrated voltage signal with a threshold voltage, and the output level signal includes:

[0050] The threshold circuit compares the integrated voltage signal with a preset threshold voltage. When the integrated voltage signal is less than the threshold voltage, it outputs a low-level signal; when the integrated voltage signal is higher than or equal to the threshold voltage, it outputs a high-level signal.

[0051] Specifically, when the threshold circuit outputs a low-level signal, the FPGA module stops outputting the frequency signal;

[0052] Further, in step S4, when the threshold circuit outputs a high-level signal, the FPGA module outputs a frequency signal. The FPGA module controls the temperature detection module to collect the temperature data of the constant current source module according to a preset time interval, and calculates the compensation current value based on the output value of the corresponding frequency signal at each temperature.

[0053] The formula for calculating the compensation current value is shown in formula (1).

[0054] When the temperature T n The output value K of the frequency signal below n The compensation current is positive when it is greater than or equal to the output reference value K0 of the frequency signal at room temperature; when the temperature T n The output value K of the frequency signal below n When the output reference value K0 of the frequency signal at room temperature is less than the value of the frequency signal at room temperature, the compensation current is negative.

[0055] The method provided in the above embodiments has at least the following beneficial effects:

[0056] By establishing the relationship between temperature and frequency signal output values, a DAC compensation circuit is introduced to control a constant current source to provide compensation current, thereby improving the accuracy of compensation and thus improving the accuracy and reliability of frequency signal conversion.

[0057] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A digital compensation based current to frequency conversion device, characterized by, It includes an integrating circuit, a threshold circuit, an FPGA module, a switching circuit, a constant current source module, a DAC compensation circuit, and a temperature detection module; The integrating circuit is used to integrate the input current to generate an integrated voltage signal; The threshold circuit compares the integrated voltage signal with a preset threshold voltage. When the integrated voltage signal is less than the threshold voltage, a low-level signal is output, and the FPGA module stops outputting the frequency signal. When the integrated voltage signal is higher than or equal to the threshold voltage, a high-level signal is output, and the FPGA module outputs the frequency signal. When the threshold circuit outputs the high-level signal, the FPGA module controls the temperature detection module to collect temperature data from the constant current source module at preset time intervals. Based on the output value of the corresponding frequency signal at each temperature, the compensation current value is calculated using the following formula: ， in, To compensate for the current value, The frequency value of the full-scale current output. In order to be in The output value of the frequency signal at temperature. This is the output reference value for the frequency signal at room temperature. The utilization rate of the constant current source module; the temperature detection module is used to collect the temperature data of the constant current source module; The FPGA module is used to output a frequency signal according to the level signal, receive the temperature data, calculate the compensation current value according to the temperature data and the output value of the frequency signal, generate a compensation control signal and send it to the DAC compensation circuit. The DAC compensation circuit is used to control the constant current source module to output a corresponding compensation current to the integrator circuit according to the compensation control signal. The switching circuit is used to control the on and off of the constant current source module.

2. The apparatus of claim 1, wherein, When the temperature The output value of the frequency signal below The output reference value of the frequency signal at room temperature is greater than or equal to the value of the frequency signal at room temperature. When the temperature is [temperature], the compensation current is positive; when the temperature is [temperature], the compensation current is positive. The output value of the frequency signal below The output reference value of the frequency signal at room temperature is less than the specified value. At that time, the compensation current is negative.

3. A current-frequency conversion method based on digital compensation using the device as described in claim 1 or 2, characterized in that, include: The input current is integrated by an integrating circuit to generate an integrated voltage signal; A threshold circuit is used to compare the integrated voltage signal with a threshold voltage and output a level signal. Temperature data from the constant current source module is collected via the temperature detection module. The FPGA module outputs a frequency signal based on the level signal, receives the temperature data, calculates the compensation current value based on the temperature data and the output value of the frequency signal, generates a compensation control signal and sends it to the DAC compensation circuit. The DAC compensation circuit is used to control the constant current source module to output the corresponding compensation current to the integrator circuit according to the compensation control signal. The constant current source module is switched on and off via a switching circuit.

4. The method of claim 3, wherein, A threshold circuit is used to compare the integrated voltage signal with a threshold voltage, and outputs a level signal, including: The threshold circuit compares the integrated voltage signal with a preset threshold voltage. When the integrated voltage signal is less than the threshold voltage, it outputs a low-level signal; when the integrated voltage signal is higher than or equal to the threshold voltage, it outputs a high-level signal.

5. The method of claim 4, wherein, When the threshold circuit outputs a low-level signal, the FPGA module stops outputting the frequency signal; When the threshold circuit outputs a high-level signal, the FPGA module outputs a frequency signal. The FPGA module controls the temperature detection module to collect the temperature data of the constant current source module according to a preset time interval, and calculates the compensation current value based on the output value of the corresponding frequency signal at each temperature.

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