Pressure sensor calibration method based on parameter interval mapping

Abstract

The invention provides a pressure sensor calibration method based on parameter interval mapping. The method comprises a parameter and configuration module, an interval mapping and scaling module and a calibration algorithm module. The effective parameter interval of the calibration coefficient of the sensor is configured, and interval mapping and numerical value scaling processing are performed on the calibration coefficient and digital data output by the sensor in the calibration process, so that pressure sensor products with different measuring ranges, different sensitivities and different nonlinear characteristics can be mapped to a unified internal numerical value representation interval; therefore, under the condition that the hardware structure and the operation bit width of the general calibration algorithm module are not changed, general calibration processing of multiple products is realized. According to the method, the implementation complexity and storage resource consumption of a digital circuit are reduced, the repeated design and verification workload caused by multi-product calibration is reduced, the universality of a system is improved, and the method is suitable for a pressure sensor chip and related electronic equipment.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit design, specifically relating to a pressure sensor calibration method based on parameter interval mapping and its implementation. Background Technology

[0002] With the rapid popularization of smart manufacturing, wearable devices, IoT terminals, and various high-precision sensing systems, sensor chips of various types, such as pressure, temperature, and acceleration, are widely used in industrial control, consumer electronics, and smart cities. Different scenarios place higher demands on the output accuracy, consistency, and linearity of sensors. Therefore, integrating digital calibration functions within the chip has become a key means to improve sensor performance.

[0003] In practical engineering applications, calibration chips for the same type of sensor often need to cover multiple product models with different ranges, sensitivities, operating conditions, and accuracy levels. Due to the significant variation in the manufacturing process of the sensor itself, the distribution of calibration parameters such as temperature drift, zero-point offset, and nonlinear error also varies considerably. Designing independent calibration algorithms or fixed coefficient ranges for each product would not only lead to repetitive chip architecture design and verification workloads but also increase hardware resource consumption. This would make it difficult for the chip to cover multiple product models with a unified architecture, resulting in a significant increase in development cycle, verification complexity, and unit cost.

[0004] In existing technologies, some calibration algorithms achieve error compensation by storing calibration coefficients within a fixed range. However, they lack support for different product types, operating ranges, and degrees of nonlinearity, resulting in poor versatility. Meanwhile, some configurable solutions often require large storage spaces, complex boundary judgment logic, or multiple calibration paths, further increasing the area and power consumption of the digital module, making it difficult to meet the needs of low-cost sensor chips. Furthermore, when the calibration range does not match the actual product parameter distribution, it may lead to coefficient overflow, insufficient compensation, or decreased accuracy. Therefore, there is an urgent need for a calibration method for pressure sensors that can flexibly adjust the calibration coefficient range according to different product models, while also possessing low storage overhead, low logic overhead, and strong adaptability, to address the shortcomings of existing calibration schemes in terms of versatility, resource consumption, and adaptability efficiency. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a pressure sensor calibration method based on parameter range mapping. This method aims to solve the problems in existing pressure sensor calibration methods, such as the difficulty in reusing calibration algorithms and the high complexity of hardware implementation due to the large differences in parameter ranges among different products. It achieves a calibration method that uniformly processes the parameter ranges of multiple pressure sensors.

[0006] Its characteristic is that it includes the following steps:

[0007] 1. Parameter range configuration steps

[0008] Based on the product type or operating conditions of the pressure sensor to be calibrated, the parameter range information corresponding to the pressure sensor is configured in the memory. The parameter range information includes at least one or more of the following: operating temperature range, zero drift range, sensitivity variation range, and pressure output range.

[0009] 2. Range mapping scaling steps

[0010] Based on the parameter range information, range mapping and scaling processing is performed on the calibration parameters of the pressure sensor and the raw digital signal output by the pressure sensor to map the calibration parameters and the raw digital signal to a predetermined internal value range.

[0011] 3. Calibration Algorithm Processing Steps

[0012] The calibration parameters and digital signals, after interval mapping and scaling, are input to the calibration algorithm module, which processes the digital signals according to a predetermined calibration algorithm and outputs the calibration results.

[0013] The calibration algorithm module is a general processing module. Its internal algorithm structure and operation bit width remain unchanged across different pressure sensor products. It adapts to different parameter ranges through the interval mapping and scaling steps.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] By configuring the parameter ranges of the pressure sensor's operating temperature range, zero drift range, sensitivity variation range, and pressure output range, and introducing range mapping scaling processing before the calibration algorithm, the conversion of different parameter ranges into a unified internal numerical range is realized, enabling the calibration algorithm to be reused under a fixed structure and fixed operation bit width.

[0016] This invention moves the adaptation process for parameter range differences between different products to the interval mapping scaling module, avoiding the need to repeatedly design calibration algorithms for different pressure sensor products, and reducing the design complexity and hardware implementation cost of the digital calibration system;

[0017] The method of this invention has good versatility and scalability, and is applicable to a variety of pressure sensor products, especially suitable for digital calibration systems of pressure sensors based on fixed-point arithmetic. Attached Figure Description

[0018] Figure 1 is an overall block diagram of a pressure sensor calibration method based on parameter interval mapping provided by the present invention.

[0019] Figure 2 is a schematic diagram of the interval mapping and scaling module provided by the present invention.

[0020] Figure 3 is a schematic diagram of the implementation process of the pressure sensor calibration method based on parameter interval mapping provided by the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings. The embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0022] like Figure 1 As shown, the calibration method of the present invention is applied to a pressure sensor system, which includes a parameter and configuration module, an interval mapping scaling module, and a calibration algorithm module.

[0023] The parameter and configuration module stores parameter range information corresponding to the current pressure sensor. This parameter range information includes one or more of the following: operating temperature range, zero-point drift range, sensitivity variation range, and pressure output range. This parameter range information can be configured according to different pressure sensor products during factory testing or system initialization and is stored in non-volatile memory or registers.

[0024] like Figure 2 As shown, this embodiment provides a fixed-point arithmetic circuit structure for an interval mapping scaling module. The circuit includes a configuration register (1), a subtractor (2), a multiplier (3), a bit width offset unit (4), an adder (5), a comparator (6), an overflow detection unit (7), and a selector (8). Each functional module works together to realize the linear mapping and fixed-point processing of the input data.

[0025] The interval mapping and scaling process can be mathematically abstracted as follows:

[0026]

[0027] in, This represents the raw pressure data output by the sensor. The integer represents the bit width of the output data. Indicates the upper limit of the output range, and Indicates the upper and lower limits of the input range. For mapping results, This represents the saturation constraint function, used to restrict the mapping result to an internal numerical range. In specific circuit implementations, to avoid introducing complex division operations and improve hardware implementation efficiency, the above mapping relationship is equivalently implemented using fixed-point arithmetic, the process of which is expressed as:

[0028]

[0029]

[0030]

[0031] in For intermediate results of multiplication, For fixed-point scaling results, For mapping intermediate results, This represents the raw pressure data output by the sensor. For fixed-point decimal places, These are the lower limits of the input and output intervals, respectively. This represents a saturation function, used to limit the output to a predetermined numerical range to avoid fixed-point arithmetic overflow and ensure the validity of the result.

[0032] The input terminal of the configuration register (1) is connected to the configuration signal written by the host computer, and the output terminal is connected to the subtractor (2), multiplier (3), adder (5), comparator (6), and selector (8) respectively, providing corresponding configuration parameters for each functional unit. It is used to pre-store the lower limit of the input range. Upper limit of output range Output range lower limit Upper limit of the output range Fixed decimal places and proportionality coefficient Among them, the aforementioned The proportionality coefficient is determined according to the following relationship:

[0033]

[0034] The first input terminal of the subtractor (2) is connected to the raw data output by the sensor. The second input terminal receives the lower limit of the input range output from the configuration register (1). The output is connected to the input of multiplier (3) to output the difference data. Difference data This is used to eliminate interval bias in the input data, ensuring that subsequent operations continue when the lower limit of the interval is zero. The relationship is expressed as:

[0035]

[0036] The first input of the multiplier (3) is connected to the output difference data of the subtractor (2). The second input terminal receives the scaling factor from the configuration register (1). The output of multiplier (3) is connected to the bit width offset unit (4) to output the intermediate result of the multiplication. Since the proportionality coefficient is in fixed-point representation, the multiplication result... For data with extended bit width. The relationship is expressed as:

[0037]

[0038] The first input of the bit-width offset unit (4) is connected to the intermediate result of the multiplier (3). The second input terminal is connected to the fixed-point decimal places output by the configuration register (1). The output is connected to an adder (5) to output the fixed-point scaling result. Before performing right-shift scaling, add half a quantization unit to the intermediate result. This is to achieve rounding operations. The specific processing relationship is as follows:

[0039]

[0040] The first input of the adder (5) is connected to the fixed-point scaling result of the bit-width offset unit (4). The second input terminal is connected to the lower limit of the range output by the configuration register (1). The output is connected to a comparator (6). The scaling result is then processed. and the lower limit of the output interval Add them together to get the intermediate mapping result. :

[0041]

[0042] The first input of the comparator (6) is connected to the adder (5), and the second input is connected to the lower limit of the output range of the configuration register (1). and the upper limit of the output range The mapping result Each with the lower limit of the output interval and the upper limit of the output range The comparison is performed to determine whether overflow or overflow has occurred. The output of the comparator (6) outputs a comparison judgment signal and sends the judgment signal to the overflow detection unit (7) and the selector (8).

[0043] The overflow detection unit (7) receives the operation results from the subtractor (2), multiplier (3), bit width offset unit (4), and adder (5) and the comparison judgment signal from the comparator (6) at its input terminal. When overflow or underflow is detected, the overflow detection unit (7) outputs the corresponding misalignment indication signal error.

[0044] The inputs of the selector (8) receive the intermediate mapping results output by the adder (5). 1. Lower limit of the output range of the configuration register (1) and the upper limit of the output range And receive a comparison judgment signal from comparator (6). Based on the comparison judgment signal, selector (8) maps intermediate results. Output range lower limit and the upper limit of the output range Select the corresponding value as the final output data. This achieves saturation limitation on the output data. The output of the selector (8) outputs the final scaled data. .

[0045] The calibration algorithm module is connected to the interval mapping scaling module and is used to perform calibration processing on the mapped digital signal. The calibration algorithm module may include, but is not limited to, one or more of temperature-related calibration, zero-point-related calibration, sensitivity-related calibration, and nonlinear-related calibration, and its internal algorithm structure and operational bit width remain unchanged across different pressure sensor products.

[0046] Correspondingly, this embodiment provides a control method for pressure sensor calibration based on parameter range mapping, such as... Figure 3 As shown, it includes the following steps:

[0047] 1. Determine one or more parameter ranges among the operating temperature range, zero drift range, sensitivity variation range, and pressure output range of the pressure sensor to be calibrated, and write the parameter range information into a memory or register;

[0048] 2. Determine the calibration parameter information corresponding to the pressure sensor, and write the calibration parameter information into a memory or register. The calibration parameter information includes multiple sets of calibration coefficients for calibration processing.

[0049] 3. The interval mapping and scaling module reads the parameter interval information and, based on the parameter interval information, performs interval mapping and numerical scaling processing on the corresponding calibration parameters and the raw digital data output by the pressure sensor, uniformly mapping data from different parameter ranges to a predetermined internal numerical interval.

[0050] 4. The calibration algorithm module receives the calibration parameters and raw digital data processed by the interval mapping and scaling module, and processes the digital data according to the predetermined calibration processing logic to generate intermediate calibration results;

[0051] 5. Repeat steps 3 and 4 to perform interval mapping and calibration processing for different types of parameter intervals and their corresponding calibration parameters in sequence;

[0052] 6. Output the final calibration data after multi-parameter calibration processing.

[0053] Through the above implementation methods, the present invention achieves unified processing of parameter ranges of different pressure sensors without changing the structure of the calibration algorithm module, thereby improving the versatility of the calibration algorithm and the system implementation efficiency.

Claims

1. A pressure sensor calibration method based on parameter interval mapping, characterized in that, Includes the following steps: (1) Configure the parameter range information corresponding to the pressure sensor according to the product type or working conditions of the pressure sensor to be calibrated. The parameter range information includes at least one or more of the following: working temperature range, zero drift range, sensitivity variation range and pressure output range. Store the parameter range information in a memory or register. (2) Before the pressure sensor output data is processed by the calibration algorithm, the parameter range information is read, and the calibration parameters of the pressure sensor and the original digital data output by the pressure sensor are processed by range mapping and numerical scaling to uniformly map the data of different parameter range ranges to the predetermined internal numerical range. (3) Input the calibration parameters and raw digital data after interval mapping and numerical scaling into the calibration algorithm module, and the calibration algorithm module processes the raw digital data according to the predetermined calibration algorithm and outputs the calibration result; Among different pressure sensor products, the algorithm structure and operation bit width of the calibration algorithm module remain unchanged, and the adaptation to different parameter ranges is achieved through the interval mapping and numerical scaling processing.

2. The method according to claim 1, characterized in that, The parameter range information includes at least one numerical range information related to the working environment or device characteristics of the pressure sensor. The numerical range information is used to characterize the effective value range of the corresponding calibration parameter or raw data.

3. The method according to claim 1, characterized in that, The interval mapping and numerical scaling process includes: Subtract the lower limit of the corresponding parameter range from the input data; Multiply the obtained difference by a pre-configured scaling factor; The result of the multiplication operation is then mapped to the predetermined internal numerical range.

4. The method according to claim 3, characterized in that, The interval mapping and numerical scaling processing are implemented using fixed-point arithmetic, and when scaling the bit width of the multiplication result, rounding is achieved by introducing a rounding compensation value.

5. The method according to claim 1, characterized in that, The interval mapping and numerical scaling process also includes comparing the upper and lower limits of the mapping result, and when the mapping result is detected to exceed the internal numerical range, the output result is saturated and limited.

6. The method according to claim 1, characterized in that, The interval mapping and numerical scaling processing are respectively applied to one or more calibration stages in temperature compensation calibration, zero-point drift calibration, sensitivity calibration, and nonlinear calibration.

7. The method according to claim 1, characterized in that, The interval mapping and numerical scaling processing are performed by an independent interval mapping and scaling module, which is decoupled from the calibration algorithm module.

8. The method according to claim 7, characterized in that, The interval mapping and scaling module includes: The subtraction unit is used to calculate the difference between the input data and the lower limit of the parameter range; A multiplication unit is used to scale the difference proportionally. The bit width adjustment unit is used to perform fixed-point bit width scaling on the multiplication result; The comparison unit is used to determine whether the data exceeds a predetermined internal value range; The selection cell is used to output scaled data based on the comparison results.

9. A pressure sensor chip, characterized in that, The method includes a memory, an interval mapping and scaling module, and a calibration algorithm module, wherein the interval mapping and scaling module and the calibration algorithm module are configured to perform the method according to any one of claims 1 to 8.

10. An electronic device, characterized in that, Includes the pressure sensor chip as described in claim 9.

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