Vehicle ad sampling device and method

Abstract

This invention provides a vehicle AD sampling device and method. The vehicle AD sampling device includes a vehicle power system, an AD sampling circuit, and a processor. In this invention, based on AD sampling of a primary reference analog voltage by the AD sampling circuit, the processor receives the primary and secondary reference analog voltages and performs analog-to-digital conversion to obtain a primary and secondary reference digital voltage. Then, the relative deviation of the primary reference analog voltage is calculated based on the primary and secondary reference digital voltages. Finally, the digital signal is calibrated based on the relative deviation. This effectively improves the AD sampling accuracy of the primary reference analog voltage, achieving high sampling precision. The corresponding hardware structure can be fully implemented based on existing hardware structures, making it simple and easy to implement. Only a small amount of additional calculation is required from the processor, and the computational load is relatively small.

Description

Technical Field

[0001] This application relates to the field of vehicle domain control technology, specifically to a vehicle AD sampling device and method. Background Technology

[0002] AD sampling circuits are widely used in various automotive fields, including temperature, pressure, and liquid level detection. The accuracy of AD sampling plays a crucial role in the performance of a control system. However, in automobiles, changes in the local application environment may cause changes in the sampling reference power supply. For example, the sampling reference power supply may change momentarily when the car starts, which can compromise the accuracy of AD sampling.

[0003] Based on this, an existing technology proposes an AD sampling value correction method. By dividing the theoretical AD sampling line and the actual AD sampling curve into multiple segments, assuming that the actual AD sampling curve in each segment is a linear line, a compensation relationship between the actual AD sampling value and the theoretical AD sampling value in each sampling interval is generated according to the correspondence between the analog input voltage value and the theoretical AD sampling value in each sampling interval. Based on the compensation relationship, the actual AD sampling value of the actual AD sampling curve corresponding to the compensation relationship is corrected, which greatly improves the AD sampling accuracy.

[0004] However, the above method uses segmented compensation based on theoretical straight lines and actual curves, which still introduces segmented error ranges. Furthermore, it assumes that the actual AD sampling curve within each segment is a linear straight line, which may not match reality. Therefore, the correction accuracy of AD sampling values ​​using this method is insufficient, and the computational load is substantial.

[0005] Therefore, there is an urgent need for a vehicle AD sampling technology solution that is simple in structure, requires little computation, and has high sampling accuracy. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the present invention provides a vehicle AD sampling technology solution to solve the above-mentioned technical problems.

[0007] To achieve the above and other related objectives, the technical solution provided by this invention is as follows.

[0008] A vehicle AD sampling device, comprising:

[0009] The vehicle power system is connected to the vehicle battery and performs DC-DC step-down conversion on the supply voltage of the vehicle battery to obtain a first-level reference analog voltage. Then, the first-level reference analog voltage is further subjected to DC-DC step-down conversion to obtain a second-level reference analog voltage.

[0010] The AD sampling circuit performs AD sampling on the first-level reference analog voltage to obtain a digital signal;

[0011] The processor receives the primary reference analog voltage, the secondary reference analog voltage, and the digital signal; performs analog-to-digital conversion on the primary reference analog voltage to obtain a primary reference digital voltage; performs analog-to-digital conversion on the secondary reference analog voltage to obtain a secondary reference digital voltage; calculates the theoretical value of the primary reference digital voltage based on the secondary reference digital voltage; calculates the relative deviation of the primary reference analog voltage based on the theoretical value and the primary reference digital voltage; and calibrates the digital signal based on the relative deviation.

[0012] Optionally, the vehicle power system includes a first power chip and a second power chip cascaded in sequence. The input terminal of the first power chip is connected to the vehicle battery. The first power chip performs DC-DC step-down conversion on the supply voltage of the vehicle battery to obtain and output the first-level reference analog voltage. The input terminal of the second power chip is connected to the output terminal of the first power chip. The second power chip performs DC-DC step-down conversion on the first-level reference analog voltage to obtain and output the second-level reference analog voltage.

[0013] Optionally, the second power supply chip has a wide input range, so that even if the first-level reference analog voltage fluctuates within a preset range, the second-level reference analog voltage remains unchanged.

[0014] Optionally, the input terminal of the AD sampling circuit is connected to the output terminal of the first power chip, and the output terminal of the AD sampling circuit is connected to the digital input terminal of the processor.

[0015] Optionally, one AD input terminal of the processor is connected to the output terminal of the first power chip, receives the first-level reference analog voltage, and performs analog-to-digital conversion on the first-level reference analog voltage to obtain the first-level reference digital voltage; the other AD input terminal of the processor is connected to the output terminal of the second power chip, receives the second-level reference analog voltage, and performs analog-to-digital conversion on the second-level reference analog voltage to obtain the second-level reference digital voltage.

[0016] Optionally, the processor calculates the theoretical value of the primary reference digital voltage based on the secondary reference digital voltage and the DC-DC buck conversion gain of the secondary reference analog voltage.

[0017] Optionally, the processor includes at least a microcontroller.

[0018] A vehicle AD sampling method, comprising:

[0019] Provide a vehicle AD sampling device as described in any of the above;

[0020] The vehicle power system performs two consecutive DC-DC step-down conversions on the supply voltage of the vehicle battery to obtain the first-level reference analog voltage and the second-level reference analog voltage.

[0021] The first-level reference analog voltage is sampled by the AD sampling circuit to obtain the digital signal;

[0022] The processor receives the primary reference analog voltage and the secondary reference analog voltage and performs analog-to-digital conversion to obtain the primary reference digital voltage and the secondary reference digital voltage.

[0023] The processor calculates the relative deviation of the first-level reference analog voltage based on the first-level reference digital voltage and the second-level reference digital voltage.

[0024] The processor receives the digital signal and calibrates the digital signal according to the relative deviation.

[0025] Optionally, the step of calculating the relative deviation of the primary reference analog voltage based on the primary reference digital voltage and the secondary reference digital voltage using the processor includes:

[0026] The processor obtains the DC-DC buck conversion gain of the secondary reference analog voltage and calculates the theoretical value of the primary reference digital voltage based on the secondary reference digital voltage and the DC-DC buck conversion gain of the secondary reference analog voltage.

[0027] The processor calculates the relative deviation of the first-level reference analog voltage based on the theoretical value of the first-level reference digital voltage and the first-level reference digital voltage.

[0028] The beneficial effects of this invention are as follows: Based on the AD sampling of the first-level reference analog voltage through the AD sampling circuit, the processor receives the first-level reference analog voltage and the second-level reference analog voltage and performs analog-to-digital conversion to obtain the first-level reference digital voltage and the second-level reference digital voltage. Then, the relative deviation of the first-level reference analog voltage is calculated based on the first-level reference digital voltage and the second-level reference digital voltage. Finally, the digital signal is calibrated based on the relative deviation. This effectively improves the AD sampling accuracy of the first-level reference analog voltage, with high sampling precision. The corresponding hardware structure can be fully implemented based on the existing hardware structure, which is simple and easy to implement. Only a small amount of additional calculation is required from the processor, and the amount of calculation is relatively small.

[0029] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of a vehicle AD sampling device shown in an exemplary embodiment of this application;

[0032] Figure 2 This is a schematic diagram illustrating the steps of a vehicle AD sampling method according to an exemplary embodiment of this application. Detailed Implementation

[0033] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0034] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0035] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0036] As described in the background section, the inventors discovered that an existing technology proposes an AD sampling value correction method. This method divides the theoretical AD sampling line and the actual AD sampling curve into multiple segments, assuming that the actual AD sampling curve in each segment is a linear line. Based on the correspondence between the analog input voltage value and the theoretical AD sampling value in each sampling interval, and the correspondence between the analog input voltage value and the actual AD sampling value, a compensation relationship between the actual AD sampling value and the theoretical AD sampling value in each sampling interval is generated. Based on the compensation relationship, the actual AD sampling value of the actual AD sampling curve corresponding to the compensation relationship is corrected to improve the AD sampling accuracy.

[0037] However, the existing technology one uses segmented compensation based on theoretical straight lines and actual curves. This still results in segmented error ranges and assumes that the actual AD sampling curve within each segment is a linear straight line, which may not match reality. Therefore, when using the existing technology one to correct AD sampling values, the correction accuracy is insufficient due to the inherent flaws in its correction principle, and the computational load is very large.

[0038] To address these issues, embodiments of this application propose a vehicle AD sampling device and a vehicle AD sampling method, which will be described in detail below.

[0039] In detail, such as Figure 1 As shown, in an exemplary embodiment of this application, a vehicle AD sampling device is proposed, which includes:

[0040] The vehicle power system is connected to the vehicle battery and performs DC-DC step-down conversion on the battery's supply voltage V0 to obtain a first-level reference analog voltage Vref1. Then, the first-level reference analog voltage Vref1 is further subjected to DC-DC step-down conversion to obtain a second-level reference analog voltage Vref2.

[0041] The AD sampling circuit performs AD sampling on the first-level reference analog voltage Vref1 to obtain the digital signal Vd;

[0042] The processor receives a primary reference analog voltage Vref1, a secondary reference analog voltage Vref2, and a digital signal Vd. It performs analog-to-digital conversion on the primary reference analog voltage Vref1 to obtain a primary reference digital voltage (not shown in the figure), performs analog-to-digital conversion on the secondary reference analog voltage Vref2 to obtain a secondary reference digital voltage (not shown in the figure), calculates the theoretical value of the primary reference digital voltage based on the secondary reference digital voltage (not shown in the figure), calculates the relative deviation of the primary reference analog voltage Vref1 based on the theoretical value and the primary reference digital voltage, and calibrates the digital signal Vd based on the relative deviation.

[0043] More in detail, such as Figure 1As shown, the vehicle power system includes a first power chip and a second power chip cascaded in sequence. The input terminal of the first power chip is connected to the vehicle battery. The first power chip performs a DC-DC step-down conversion on the supply voltage V0 of the vehicle battery to obtain and output a first-level reference analog voltage Vref1, which is used for input to the AD sampling circuit and the second power chip. The input terminal of the second power chip is connected to the output terminal of the first power chip. The second power chip performs a DC-DC step-down conversion on the first-level reference analog voltage Vref1 to obtain and output a second-level reference analog voltage Vref2, which provides a low-level power supply to the system.

[0044] The vehicle battery supply voltage V0 can be 12V or 24V, the first-level reference analog voltage Vref1 can be 5V or 3.3V, and the second-level reference analog voltage Vref2 can be 1.8V or 1.2V. These can be selected and set according to actual needs, and are not limited here. The first and second power supply chips can be conventional DC-DC step-down power management chips, which will not be elaborated here. In order to ensure that the AD sampling value range is large enough, the sampling object of the AD reference power supply and the AD sampling circuit is the first-level reference analog voltage Vref1 output by the first power supply chip.

[0045] It should be emphasized that the second power supply chip has a wide input range. Even if the primary reference analog voltage Vref1 fluctuates within the preset range, such as dropping to two or three volts, the secondary reference analog voltage Vref2 remains unchanged.

[0046] More in detail, such as Figure 1 As shown, the input terminal of the AD sampling circuit is connected to the output terminal of the first power supply chip, and the output terminal of the AD sampling circuit is connected to the digital input terminal of the processor. The AD sampling circuit performs AD sampling on the first-level reference analog voltage Vref1 to obtain the digital signal Vd and feeds it back to the processor.

[0047] More in detail, such as Figure 1 As shown, one AD input terminal of the processor is connected to the output terminal of the first power supply chip, receives the first-level reference analog voltage Vref1, and performs analog-to-digital conversion on the first-level reference analog voltage Vref1 to obtain the first-level reference digital voltage (not shown in the figure); the other AD input terminal of the processor is connected to the output terminal of the second power supply chip, receives the second-level reference analog voltage Vref2, and performs analog-to-digital conversion on the second-level reference analog voltage Vref2 to obtain the second-level reference digital voltage (not shown in the figure).

[0048] More in detail, such as Figure 1As shown, when the vehicle starts, especially at the moment of starting, the vehicle battery's supply voltage V0 will fluctuate significantly, causing the first-level reference analog voltage Vref1 output by the first power chip to change. At this time, the value collected by the AD sampling circuit is no longer accurate, such as changing from the theoretical value of 5V to the actual value of 4.7V.

[0049] At this point, because the second power supply chip has a wide input range, even when the primary reference analog voltage Vref1 drops to two or three volts, its output secondary reference analog voltage Vref2 can remain stable. The processor collects the secondary reference analog voltage Vref2 internally and compares it with the primary reference analog voltage Vref1. The deviation value of the primary reference analog voltage Vref1 is deduced from the constant secondary reference analog voltage Vref2, and then the deviation value of the AD sampling value is obtained. Based on this deviation value, the AD sampling output is calibrated, thus ensuring the accuracy of the sampling.

[0050] This design utilizes the existing secondary reference analog voltage Vref2 in the power supply system. Only one additional trace is needed to acquire the secondary reference analog voltage Vref2 to the processor's AD port. Its structure is simple and easy to implement.

[0051] More in detail, such as Figure 1 As shown, the processor receives the primary reference analog voltage Vref1, the secondary reference analog voltage Vref2, and the digital signal Vd and performs analog-to-digital conversion to obtain the primary reference digital voltage (not shown in the figure) and the secondary reference digital voltage (not shown in the figure). The processor also obtains the DC-DC buck conversion gain of the secondary reference analog voltage Vref2, or the actual voltage gain of the second power supply chip (which can be obtained directly through communication with the second power supply chip). The processor then calculates the theoretical value of the primary reference digital voltage (not shown in the figure) based on the secondary reference digital voltage and the DC-DC buck conversion gain of the secondary reference analog voltage. After that, it calculates the relative deviation of the primary reference analog voltage Vref1 based on the theoretical value of the primary reference digital voltage and the primary reference digital voltage. Finally, it calibrates the digital signal Vd based on the relative deviation.

[0052] The processor can be a single-chip microcomputer or microcontroller (MCU), a general-purpose processor such as a central processing unit (CPU) or network processor (NP), or a digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, without limitation.

[0053] Based on such Figure 1 In another exemplary embodiment of this application, a vehicle AD sampling method is also provided, as shown in the vehicle AD sampling device illustrated. Figure 2 As shown, it includes the following steps:

[0054] S1. Provide the aforementioned vehicle AD sampling device;

[0055] S2. The vehicle power supply voltage to the vehicle battery is converted into a first-level reference analog voltage and a second-level reference analog voltage by performing two consecutive DC-DC step-down conversions through the vehicle power system.

[0056] S3. The first-level reference analog voltage is sampled by an AD sampling circuit to obtain a digital signal;

[0057] S4. The processor receives the primary reference analog voltage and the secondary reference analog voltage and performs analog-to-digital conversion to obtain the primary reference digital voltage and the secondary reference digital voltage.

[0058] S5. Using the processor, calculate the relative deviation of the primary reference analog voltage based on the primary reference digital voltage and the secondary reference digital voltage;

[0059] S6. The processor receives digital signals and calibrates them based on the relative deviation.

[0060] In detail, step S5, which involves the processor calculating the relative deviation of the primary reference analog voltage based on the primary reference digital voltage and the secondary reference digital voltage, further includes:

[0061] S51. The processor obtains the DC-DC buck conversion gain of the secondary reference analog voltage and calculates the theoretical value of the primary reference digital voltage based on the DC-DC buck conversion gain of the secondary reference digital voltage and the secondary reference analog voltage.

[0062] S52. Using the processor, calculate the relative deviation of the primary reference analog voltage based on the theoretical value of the primary reference digital voltage and the primary reference digital voltage.

[0063] More specifically, in step S5, the theoretical value of the first-level reference digital voltage, i.e., the theoretical design value of the first-level reference digital voltage, is first calculated by using the almost constant DC-DC buck conversion gain of the second-level reference digital voltage and the second-level reference analog voltage. Then, the relative deviation of the first-level reference analog voltage is calculated based on the theoretical value of the first-level reference digital voltage and the theoretical design value and actual value of the first-level reference digital voltage. Subsequently, in step S6, the digital signal can be calibrated and corrected based on the relative deviation to obtain a high-precision AD sampling digital signal.

[0064] In summary, the vehicle AD sampling device and method provided by this invention, based on AD sampling of the primary reference analog voltage through the AD sampling circuit, receive the primary and secondary reference analog voltages through the processor and perform analog-to-digital conversion to obtain the primary and secondary reference digital voltages. Then, the relative deviation of the primary reference analog voltage is calculated based on the primary and secondary reference digital voltages, and finally, the digital signal is calibrated based on the relative deviation. This effectively improves the AD sampling accuracy of the primary reference analog voltage, resulting in high sampling precision. The corresponding hardware structure can be fully implemented based on existing hardware structures, making the structure simple and easy to implement. Only a small amount of additional calculation is required from the processor, and the computational load is relatively small.

[0065] It is important to emphasize that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functions, and operations that a system may implement according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0066] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A vehicle AD sampling device, characterized in that, include: The vehicle power system is connected to the vehicle battery and performs DC-DC step-down conversion on the supply voltage of the vehicle battery to obtain a first-level reference analog voltage. The first-level reference analog voltage is then subjected to DC-DC step-down conversion to obtain a second-level reference analog voltage. When the first-level reference analog voltage fluctuates within a preset range, the second-level reference analog voltage remains unchanged. The AD sampling circuit performs AD sampling on the first-level reference analog voltage to obtain a digital signal; The processor receives the primary reference analog voltage, the secondary reference analog voltage, and the digital signal; performs analog-to-digital conversion on the primary reference analog voltage to obtain a primary reference digital voltage; performs analog-to-digital conversion on the secondary reference analog voltage to obtain a secondary reference digital voltage; calculates the theoretical value of the primary reference digital voltage based on the secondary reference digital voltage; calculates the relative deviation of the primary reference analog voltage based on the theoretical value and the primary reference digital voltage; and calibrates the digital signal based on the relative deviation.

2. The vehicle AD sampling device according to claim 1, characterized in that, The vehicle power system includes a first power chip and a second power chip cascaded in sequence. The input terminal of the first power chip is connected to the vehicle battery. The first power chip performs DC-DC step-down conversion on the supply voltage of the vehicle battery to obtain and output the first-level reference analog voltage. The input terminal of the second power chip is connected to the output terminal of the first power chip. The second power chip performs DC-DC step-down conversion on the first-level reference analog voltage to obtain and output the second-level reference analog voltage.

3. The vehicle AD sampling device according to claim 2, characterized in that, The second power supply chip has a wide input range, so even if the first-level reference analog voltage fluctuates within a preset range, the second-level reference analog voltage remains unchanged.

4. The vehicle AD sampling device according to claim 2, characterized in that, The input terminal of the AD sampling circuit is connected to the output terminal of the first power chip, and the output terminal of the AD sampling circuit is connected to the digital input terminal of the processor.

5. The vehicle AD sampling device according to claim 4, characterized in that, One AD input terminal of the processor is connected to the output terminal of the first power chip, receives the first-level reference analog voltage, and performs analog-to-digital conversion on the first-level reference analog voltage to obtain the first-level reference digital voltage; the other AD input terminal of the processor is connected to the output terminal of the second power chip, receives the second-level reference analog voltage, and performs analog-to-digital conversion on the second-level reference analog voltage to obtain the second-level reference digital voltage.

6. The vehicle AD sampling device according to claim 5, characterized in that, The processor calculates the theoretical value of the primary reference digital voltage based on the secondary reference digital voltage and the DC-DC buck conversion gain of the secondary reference analog voltage.

7. The vehicle AD sampling device according to claim 5, characterized in that, The processor includes at least a microcontroller.

8. A vehicle AD sampling method, characterized in that, include: Provide a vehicle AD sampling device according to any one of claims 1-7; The vehicle power system performs two consecutive DC-DC step-down conversions on the supply voltage of the vehicle battery to obtain the first-level reference analog voltage and the second-level reference analog voltage. The first-level reference analog voltage is sampled by the AD sampling circuit to obtain the digital signal; The processor receives the primary reference analog voltage and the secondary reference analog voltage and performs analog-to-digital conversion to obtain the primary reference digital voltage and the secondary reference digital voltage. The processor calculates the relative deviation of the first-level reference analog voltage based on the first-level reference digital voltage and the second-level reference digital voltage. The processor receives the digital signal and calibrates the digital signal according to the relative deviation.

9. The vehicle AD sampling method according to claim 8, characterized in that, The step of calculating the relative deviation of the primary reference analog voltage based on the primary reference digital voltage and the secondary reference digital voltage using the processor includes: The processor obtains the DC-DC buck conversion gain of the secondary reference analog voltage and calculates the theoretical value of the primary reference digital voltage based on the secondary reference digital voltage and the DC-DC buck conversion gain of the secondary reference analog voltage. The processor calculates the relative deviation of the first-level reference analog voltage based on the theoretical value of the first-level reference digital voltage and the first-level reference digital voltage.

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