Induction cooker type judgment system and method based on chip built-in PGA

Abstract

The invention discloses an induction cooker type judgment system and method based on a chip built-in PGA. The induction cooker type judgment system comprises a current sampling module, a signal amplification module, a signal processing module, a counting module and a judgment module. The current sampling module acquires pulse current in real time when the IGBT is switched on and off through a sampling resistor R and converts the pulse current into a small voltage signal; the differential PGA uses Verf as a bias reference, the amplification factor is dynamically adjusted, and the signal is amplified to an effective detection interval; the signal processing module monitors signals through ADC conversion and a comparator module dual path, a comparator pre-calibrates a VDAC1 / VDAC2 threshold value, and a high-frequency interference trigger overturning signal is accurately captured; the counting module counts the number of overturning times in unit time; and the judgment module identifies the type of the cookware through a multi-dimensional matching algorithm based on the counting value curve characteristics of the full power range, and calls a power control strategy to adjust IGBT switch parameters. According to the invention, efficient identification and power optimization control of the induction cooker on cookware made of different materials are realized, and the induction cooker has high reliability and scene adaptability.

Description

Technical Field

[0001] The present invention relates to the field of differentiating IH heating device types, and particularly to an induction cooker cookware type judgment system and method based on an on-chip built-in PGA. Background Art

[0002] In the application scenarios of IH heating devices (such as induction cookers), the types of cookware are rich and diverse. Cookware of different materials (such as iron, stainless steel, aluminum, etc.) have significant differences in aspects such as heating power response and electromagnetic characteristics. To achieve efficient heating and precise control, accurately judging the cookware type has become a key requirement. However, traditional cookware differentiation technologies face many challenges: on the one hand, early solutions mostly rely on physical property detection (such as cookware weight and size measurement), and such methods cannot distinguish cookware of the same specifications but different materials, with limited practicality; on the other hand, some detection technologies based on current signals, due to not fully considering the complex voltage environment when the IGBT works, especially in the scenario of non-zero voltage conduction of the IGBT, it is difficult to effectively process high-frequency interference signals, resulting in distortion of the collected current signals, and ultimately affecting the accuracy of cookware differentiation.

[0003] The core drawback of the prior art is reflected in the signal processing level. Traditional solutions lack a targeted processing mechanism for the high-frequency pulsed current and oscillation interference generated when the IGBT conducts. When the IGBT conducts with a relatively high C - pole voltage or a voltage lower than the ground voltage, the positive or negative high-frequency pulsed current is amplified and easily causes signal anomalies. Traditional methods do not set reasonable comparison reference voltage thresholds (such as lacking a precise VDAC1 and VDAC2 setting mechanism), and cannot accurately capture high-frequency interference signals, resulting in misjudgment or missed judgment by the counting module, and ultimately causing deviation in the cookware type differentiation result.

[0004] In addition, some traditional solutions have deficiencies in system design. For example, the hardware architecture is complex, relying on additional sensors or detection modules, increasing the device cost and circuit design difficulty; in terms of the analysis logic, only single-point power detection is used, and the characteristics of the count value curve in the full power range are not systematically combined for comprehensive judgment, making it difficult to form a complete cookware characteristic analysis model. These defects make traditional technologies unable to meet the requirements of modern IH devices for efficient and accurate cookware differentiation in multi-power dynamic change scenarios, and innovative technical solutions are urgently needed to solve the above problems. Summary of the Invention

[0005] In order to overcome the disadvantages and deficiencies of the prior art, the present invention provides an induction cooker cookware type judgment system and method based on an on-chip built-in PGA.

[0006] On the one hand, the present invention proposes an induction cooker cookware type judgment system based on an on-chip built-in PGA, and the system includes:

[0007] The current sampling module includes a sampling resistor R, which is used to collect the pulsed current signal of the power loop when the IGBT is switched, and convert the current signal into a small voltage signal;

[0008] The signal amplification module is an on-chip differential PGA, which is used to select the built-in bias voltage of Verf and amplify the small voltage signal by a specified multiple, and output the amplified signal;

[0009] The signal processing module includes an ADC module and a comparator module. The ADC module converts the amplified analog current signal into a digital variable for power calculation and control reference; the comparator module sets comparison reference voltages VDAC1 and VDAC2 to monitor whether the amplified signal exceeds the range, and outputs a flip signal when it does;

[0010] The counting module is a counter inside the CPU, which receives the flip signal and counts;

[0011] The judgment module judges the type of cookware and matches the control power according to the value of the counter within a unit time and the characteristics of the count value curve at different power points within the entire controllable power range.

[0012] Further, the differential PGA adopts a differential input structure, takes Verf as the bias reference, amplifies the differential small voltage signal output by the sampling resistor R, and the amplification multiple is configurable to meet the amplification requirements of the current signal under different power scenarios.

[0013] Further, the comparator module includes one or more comparators. The comparator reference voltages VDAC1 and VDAC2 are generated by the on-chip DAC module. VDAC1 is set as the signal upper limit threshold, and VDAC2 is set as the signal lower limit threshold. When the PGA output signal exceeds VDAC1 or is lower than VDAC2, the comparator flips and triggers the counting module.

[0014] Further, the ADC module collects the PGAOUT voltage through hardware triggering when the IGBT is conducting, converts the analog signal into a digital quantity, and outputs it to the built-in digital comparator; the digital comparator sets the comparison upper limit and lower limit, and the comparison result is used to control the counting of the counting module.

[0015] Further, it further includes a power control module. The judgment module calls the pre-stored power control strategy according to the identified cookware type, and adjusts the switching parameters of the IGBT through the power control module to achieve the power output adapted to the cookware.

[0016] On the other hand, the present invention proposes a method for judging the type of induction cooker cookware based on the on-chip PGA, and this method includes the following steps:

[0017] Step S1: Current signal acquisition. The pulsed current in the power circuit during IGBT switching is collected through the sampling resistor R and converted into a small voltage signal, which is input into the built-in differential PGA of the chip.

[0018] Step S2: Signal amplification. The differential PGA selects the Verf bias voltage to amplify the small voltage signal and outputs it to the ADC module and the comparator module.

[0019] Step S3: Signal processing. The ADC module converts the amplified signal into a digital variable. The comparator module determines whether the signal is out of range through VDAC1 and VDAC2, and outputs a flip signal when it is out of range.

[0020] Step S4: Counting. The internal counter of the CPU counts the flip signals and records the count value per unit time.

[0021] Step S5: Cookware judgment. Within the controllable power range of the product, the count value per unit time at different power points is obtained to generate a count value curve, and the type of cookware is judged according to the curve characteristics.

[0022] Further, in the signal amplification step, the amplification factor of the differential PGA is dynamically adjusted according to the preset power range of the system. A high amplification factor is selected in the low-power scenario, and a low amplification factor is selected in the high-power scenario to ensure that the signals input into the ADC and the comparator module are within the effective detection range.

[0023] Further, in the signal processing step, the voltage values of VDAC1 and VDAC2 of the comparator module are pre-calibrated according to the C-pole voltage characteristics when the IGBT is conducting. When the IGBT conducts at a relatively high C-pole voltage, the positive high-frequency pulsed current is likely to trigger VDAC1 after amplification. When the IGBT conducts at a C-pole voltage lower than the ground voltage, the negative high-frequency pulsed current is likely to trigger VDAC2 after amplification.

[0024] Further, in the cookware judgment step, standard count value curves of multiple cookware types are pre-stored, and the type of cookware is determined by calculating the matching degree between the current count value curve and the standard curve. The matching degree calculation includes dimensions such as the similarity of curve shapes, the difference in the mean of the count values per unit time, and the difference in the distribution characteristics of the count values at power points.

[0025] Further, it also includes a system calibration step: after system initialization or replacement of key components, through testing with a standard cookware, the count values at different power points are collected to generate a calibration curve and update the system parameters to ensure the accuracy of cookware discrimination.

[0026] Beneficial effects:

[0027] The present invention proposes an induction cooker cookware type judgment system and method based on an on-chip PGA. The system adopts a modular design. The current sampling module accurately samples the pulsed current during IGBT switching and converts it into a small voltage signal. The on-chip differential PGA uses Verf as the bias reference, and the amplification factor can be flexibly configured to adapt to different power scenarios and ensure that the input signal is within the effective detection range. The comparator module generates VDAC1 and VDAC2 thresholds through the built-in DAC, and combines single / multi-comparator designs to accurately capture signal flips outside the range and trigger counting. The ADC module and the digital comparator work together to form a dual-path signal processing mechanism to improve detection reliability. The power control module matches the pre-stored strategy according to the cookware type to achieve accurate adjustment of IGBT switching parameters. At the method level, it covers the entire process from current acquisition, signal amplification, processing, counting to cookware judgment. The signal amplification factor dynamically adapts to the power scenario, and VDAC1 and VDAC2 are pre-calibrated based on the IGBT conduction characteristics to specifically capture high-frequency interference. The cookware judgment introduces multi-dimensional matching degree calculation, comparing the shape, mean difference, distribution characteristics, etc. of the standard count value curve to improve the judgment accuracy. A system calibration step is also set to update parameters through testing with standard cookware to ensure the resolution accuracy after initialization or device replacement. Overall, the system and method are outstanding in signal processing accuracy, scenario adaptability, cookware judgment accuracy, and long-term system reliability, providing an intelligent and accurate cookware discrimination and power control solution for IH heating equipment, and effectively solving the problem of differential identification of different cookware materials in power response. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a block diagram of the system modules of the present invention.

[0029] Figure 2 It is a flowchart of the method steps of the present invention; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following further describes this application in detail with reference to the drawings and specific embodiments.

[0031] As Figure 1 described, an induction cooker cookware type judgment system based on an on-chip PGA, the system includes:

[0032] A current sampling module, including a sampling resistor R, for sampling the pulsed current signal of the power circuit during IGBT switching and converting the current signal into a small voltage signal;

[0033] Specifically, the current sampling module: As the front-end module for system signal acquisition, its core component is the sampling resistor R. During the IGBT switching operation, a pulsed current is generated in the power loop. At this time, the sampling resistor R intervenes in real time to collect this current signal. Based on Ohm's law, the current signal will be converted into a small voltage signal proportional to it. This process is the starting point of the entire system signal processing. Accurate current acquisition ensures the quality of the original data for subsequent signal processing, provides a real and effective voltage signal input for the subsequent modules, and is the basic link for the system to achieve the function of differentiating cookware.

[0034] The signal amplification module is an on-chip differential PGA, which is used to select the built-in bias voltage of Verf and amplify the small voltage signal by a specified multiple, and output the amplified signal;

[0035] Specifically, the signal amplification module: Adopts the on-chip differential PGA (programmable gain amplifier), uses the built-in bias voltage of Verf as the reference, and constructs a differential input structure. Its core function is to amplify the weak differential small voltage signal output by the sampling resistor R. By flexibly selecting the amplification multiple, the small voltage signal can be amplified to a range suitable for subsequent processing. For example, a high amplification multiple is selected in a low-power scenario, and a low amplification multiple is selected in a high-power scenario to ensure that the input signal amplitude adapts to the detection requirements of the subsequent ADC module and comparator module, and improves the processability and analysis accuracy of the signal.

[0036] The signal processing module includes an ADC module and a comparator module. The ADC module converts the amplified analog current signal into digital variables for power calculation and control reference; the comparator module sets comparison reference voltages VDAC1 and VDAC2 to monitor whether the amplified signal exceeds the range, and outputs a flip signal when it exceeds;

[0037] Specifically, the signal processing module: Includes two key units. One is the ADC module, which is responsible for converting the amplified analog current signal into digital variables. These digital variables are not only used for the power calculation of the system, but also provide data reference for the power control strategy to help the system achieve precise adjustment of the heating power; the other is the comparator module, which sets VDAC1 (signal upper limit threshold) and VDAC2 (signal lower limit threshold) to monitor the amplified signal in real time. When the signal exceeds VDAC1 or is lower than VDAC2, the comparator immediately outputs a flip signal to accurately capture the abnormal fluctuations of high-frequency interference signals and provide a trigger signal for subsequent counting.

[0038] The counting module is a counter inside the CPU, which receives the flip signal and counts;

[0039] Specifically, the counting module: As an internal counter of the CPU, it is a key connection module for signal processing and final judgment. Its function is to receive the flip signal output by the comparator module and count the number of signal flips within a unit time. By recording these count values, the occurrence frequency of high-frequency interference signals within a unit time is quantified. These counting results not only reflect the interference characteristics of the current signal but also provide core data for the judgment module, which is the key quantitative basis for the system to distinguish the type of cookware.

[0040] The judgment module determines the type of cookware and matches the control power according to the counter value within a unit time and the characteristics of the count value curve at different power points within the entire controllable power range.

[0041] Specifically, the judgment module: As the core decision-making unit of the system, it undertakes the final task of distinguishing the type of cookware and matching the power. This module first collects the counter value within a unit time, then traverses the entire controllable power range of the product, obtains the count values at different power points and generates the corresponding curve. By analyzing the characteristics of the curve through a preset algorithm, such as the curve shape, the distribution law of count values, the change trend between power points, etc., it is compared and matched with the pre-stored characteristic curves of different cookware types. Once the type of cookware is determined, the pre-stored power control strategy is immediately called to match the most suitable control power for the current cookware, realizing the intelligent adaptation and efficient heating control of the IH device for different cookware.

[0042] Furthermore, the differential PGA adopts a differential input structure, uses Verf as the bias reference, and amplifies the differential small voltage signal output by the sampling resistor R. The amplification factor is configurable to meet the amplification requirements of the current signal under different power scenarios.

[0043] Specifically, this differential PGA adopts a differential input structure. This design can effectively suppress common-mode interference and ensure that the differential small voltage signal output by the sampling resistor R maintains a high signal-to-noise ratio during transmission and amplification. Using Verf as the bias reference provides a stable reference potential for signal amplification, avoiding distortion caused by signal offset. Its amplification factor has the configurable characteristic, which means that the system can be flexibly adjusted according to the actual power scenario: in a low-power scenario, because the current signal is weak, selecting a high amplification factor can amplify the signal to a suitable detection range; in a high-power scenario, the current signal is strong, and a low amplification factor can prevent signal saturation and distortion, ensuring that the signal output to the subsequent module is both clear and distortion-free, fully meeting the accurate amplification requirements of the current signal under different power scenarios.

[0044] Further, the comparator module includes one or more comparators. The comparator reference voltages VDAC1 and VDAC2 are generated by the built-in DAC module of the chip. VDAC1 is set as the signal upper limit threshold, and VDAC2 is set as the signal lower limit threshold. When the PGA output signal exceeds VDAC1 or is lower than VDAC2, the comparator flips and triggers the counting module.

[0045] Specifically, the comparator module innovatively integrates one or more comparators to form a more flexible signal monitoring mechanism. Among them, the comparator reference voltages VDAC1 and VDAC2 are generated by the built-in DAC module of the chip. This digital generation method can accurately set the thresholds. VDAC1 serves as the signal upper limit threshold, and VDAC2 serves as the lower limit threshold to define the normal signal range in real time. When the PGA output signal has high-frequency interference due to scenarios such as non-zero voltage conduction of IGBTs and exceeds VDAC1 or is lower than VDAC2, the comparator quickly flips its state and triggers the counting module to work. The multi-comparator design can monitor signal anomalies in different dimensions in parallel, improving the comprehensiveness and timeliness of capturing high-frequency interference signals and providing a more accurate trigger signal for subsequent counting analysis.

[0046] Further, the ADC module collects the PGAOUT voltage through hardware triggering when the IGBT is turned on, converts the analog signal into a digital quantity, and outputs it to the built-in digital comparator; the digital comparator sets the comparison upper limit and lower limit, and the comparison result is used to control the counting of the counting module.

[0047] Specifically, the ADC module collects the PGAOUT voltage through hardware triggering at the critical moment when the IGBT is turned on to ensure that an effective signal containing rich interference characteristics is collected. The collected analog signal is converted into a digital quantity by the ADC and output to the built-in digital comparator. This digital comparator continues the signal range monitoring function, sets independent comparison upper and lower limits, and makes a secondary judgment on the digital quantity after ADC conversion. When the digital quantity exceeds the preset range, a control signal is output to the counting module. This design forms a dual monitoring path of "analog comparison + digital comparison", which not only supplements the function of the comparator module but also further improves the accuracy of interference signal judgment through the high-precision characteristics of digital signal processing, providing a more reliable counting basis for the counting module.

[0048] Further, it also includes a power control module. The judgment module calls the pre-stored power control strategy according to the identified type of cookware and adjusts the switching parameters of the IGBT through the power control module to achieve power output adapted to the cookware.

[0049] Specifically, the newly added power control module in the system constructs a complete closed-loop from cookware identification to power adaptation. After the judgment module determines the cookware type, it calls the pre-stored power control strategies, which are preset based on parameters such as the electromagnetic characteristics and heating requirements of different cookware. By adjusting the switching parameters of the IGBT through the power control module, such as the switching frequency, conduction time, driving voltage, etc., the power output is precisely changed. For example, in view of the fast heat conduction characteristic of iron cookware, the conduction time of the IGBT is reduced to control the power; for stainless steel cookware, the switching frequency is adjusted to improve the heating efficiency. Finally, the power output is dynamically adapted according to the cookware type, which not only ensures the heating effect but also avoids power waste or device overload, significantly improving the intelligence and efficiency level of the IH device.

[0050] As Figure 2 described, a method for judging the type of cookware of an induction cooker based on the built-in PGA of the chip, the method includes the following steps:

[0051] Step S1: Current signal acquisition, the pulsed current of the power circuit during the IGBT switching is collected through the sampling resistor R and converted into a small voltage signal and input into the built-in differential PGA of the chip;

[0052] This step takes the sampling resistor R as the core component to collect the pulsed current of the power circuit in real time at the moment of IGBT switching. Using Ohm's law to convert the current signal into a differential small voltage signal, ensuring that the original current waveform containing the cookware material characteristics can be captured during the high-frequency oscillation process of the power circuit, providing basic data for subsequent signal processing.

[0053] Step S2: Signal amplification, the differential PGA selects the Verf bias voltage to amplify the small voltage signal and outputs it to the ADC module and the comparator module;

[0054] In this step, the built-in differential PGA of the chip uses Verf as the bias reference and adopts a differential input structure to perform configurable gain amplification on the small voltage signal. By dynamically adjusting the amplification factor (low power high gain / high power low gain), the weak signal is amplified to the effective detection range of the ADC module and the comparator module, while suppressing the common-mode interference to ensure that the signal is not distorted.

[0055] Step S3: Signal processing, the ADC module converts the amplified signal into a digital variable; the comparator module judges whether the signal exceeds the range through VDAC1 and VDAC2, and outputs a flip signal when the range is exceeded;

[0056] When the IGBT is turned on, the ADC module in this step is triggered by hardware to collect the PGAOUT voltage. After completing the analog-to-digital conversion, it outputs to the digital comparator. The comparator module monitors in real time whether the amplified signal exceeds the ±3dB dynamic range through the VDAC1 / VDAC2 thresholds generated by the built-in DAC. When the signal exceeds VDAC1 or is lower than VDAC2, it triggers the comparator to flip and output a pulse signal.

[0057] Step S4: Counting. The internal counter of the CPU counts the flip signals and records the count value per unit time.

[0058] In this step, the internal counter of the CPU performs edge detection on the flip signals and counts the number of pulses per unit time (such as the count within a 10ms period). This count value directly reflects the density of high-frequency interference signals and is a quantitative indicator of the characteristics of the cookware material.

[0059] Step S5: Cookware judgment. Within the controllable power range of the product, obtain the count values per unit time at different power points, generate a count value curve, and judge the type of cookware according to the characteristics of the curve.

[0060] In this step, the count values are sampled at a fixed step (such as 50W) within the full power range (such as 100W - 2500W) to construct a power-count curve. The similarity between the current curve and the standard cookware curve is calculated through the dynamic time warping (DTW) algorithm. Combining characteristic parameters such as the curve slope and peak distribution, accurate classification of the cookware type (such as cast iron, stainless steel, composite bottom, etc.) is achieved, and the corresponding power control strategy is called.

[0061] Furthermore, in the signal amplification step, the amplification factor of the differential PGA is dynamically adjusted according to the system preset power range. A high amplification factor is selected for low-power scenarios, and a low amplification factor is selected for high-power scenarios to ensure that the signals input to the ADC and the comparator module are within the effective detection range.

[0062] This design dynamically adjusts the amplification factor of the differential PGA by real-time monitoring the preset power range of the system, achieving precise adaptation between the signal amplitude and the detection module. Specifically, when the system is in the low-power mode (e.g., below 300W), since the amplitude of the current signal is small, the differential PGA automatically switches to the high-gain mode (e.g., ×100 times), boosting the weak voltage signal to the effective quantization range of the ADC module (usually 0 - 3V) to avoid quantization errors caused by overly weak signals. In high-power scenarios (e.g., above 2000W), the amplitude of the current signal itself is large, and the differential PGA then switches to the low-gain mode (e.g., ×10 times) to prevent the signal from exceeding the input range of the ADC and comparator modules and causing saturation distortion. This adaptive gain adjustment mechanism is achieved through a built-in power-gain mapping table, ensuring that the input signal always remains within the optimal detection range across the full power range, enhancing the signal-to-noise ratio and stability of signal processing.

[0063] Furthermore, in the signal processing step, the voltage values of VDAC1 and VDAC2 in the comparator module are pre-calibrated and set according to the C-pole voltage characteristics when the IGBT conducts. When the IGBT conducts at a relatively high C-pole voltage, the forward high-frequency pulse current is likely to trigger VDAC1 after amplification; when the IGBT conducts at a C-pole voltage lower than the ground voltage, the negative high-frequency pulse current is likely to trigger VDAC2 after amplification.

[0064] The threshold settings of VDAC1 and VDAC2 in the comparator module are pre-calibrated based on the non-linear characteristics of the C-pole voltage when the IGBT conducts. Specifically, when the IGBT conducts at a relatively high C-pole voltage (e.g., exceeding 80% of the power supply voltage), a forward high-frequency pulse current will be generated in the power loop. After being amplified by the differential PGA, its peak voltage may exceed 1.2 times of Verf. At this time, VDAC1 is set to 1.1 times of Verf through pre-calibration to ensure that the forward interference triggers the comparator to flip. When the IGBT conducts at a C-pole voltage lower than the ground (i.e., negative voltage), the negative high-frequency pulse current after amplification may be lower than 0.2 times of Verf. At this time, VDAC2 is set to 0.3 times of Verf to accurately capture the negative interference. This threshold setting based on the waveform characteristics of the C-pole voltage establishes a voltage-threshold mapping relationship by offline testing the C-pole voltage waveforms at different powers, enabling the comparator module to dynamically adapt to changes in the IGBT operating state and enhancing the sensitivity and specificity of high-frequency interference signal detection.

[0065] Furthermore, in the cookware judgment step, standard count value curves of multiple cookware types are pre-stored, and the cookware type is determined by calculating the matching degree between the current count value curve and the standard curve. The matching degree calculation includes dimensions such as the similarity of curve shapes, the difference in the mean count value per unit time, and the difference in the count value distribution characteristics at power points.

[0066] The cookware judgment module achieves precise classification by constructing a multi-dimensional feature space. First, the pre-stored standard count value curves contain the count features of typical cookware (such as cast iron, stainless steel, aluminum, etc.) within the full power range. Each curve consists of 100 - 200 power point data. When the current count value curve is detected, the system uses the Dynamic Time Warping (DTW) algorithm to calculate the curve shape similarity and combines it with statistical feature analysis: ① The mean difference calculates the average difference in the count value per unit time within the full power range. For example, due to the high magnetic permeability of the cast iron pot material, the average count value is usually 30% - 50% higher than that of the stainless steel pot; ② The distribution feature difference quantifies the deviation degree of the count distribution through the Kullback-Leibler divergence. For example, the count of the aluminum pot is sparse in the low power section and dense in the high power section; ③ The curve slope analyzes the change trend in different power intervals. For example, the count growth rate of the composite bottom cookware in the medium and high power sections is significantly higher than that of the single material cookware. This multi-dimensional matching mechanism effectively solves the problem that single features are vulnerable to noise interference, enabling the system to maintain a classification accuracy of over 95% in a complex electromagnetic environment.

[0067] Furthermore, it also includes a system calibration step: after system initialization or replacement of key components, through testing with standard cookware, the count values at different power points are collected to generate a calibration curve and update the system parameters to ensure the accuracy of cookware discrimination.

[0068] The system calibration step establishes reference parameters through testing with standard cookware to ensure the detection accuracy during long-term use. The specific process is as follows: after system initialization or replacement of key components (such as IGBT, sampling resistor), a full power scan is performed using a NIST-certified standard cookware (such as a 430 stainless steel pot with a diameter of 24 cm), and the count values at each power point are recorded to generate a calibration curve. During the calibration process, the system automatically compensates for the effects of component aging, temperature drift, etc. on signal acquisition. For example, the temperature coefficient of the sampling resistor is corrected through linear regression, or the comparator threshold is adjusted according to the ADC reference voltage drift. The calibration data is stored in the EEPROM and loaded and updated with the system parameters each time the power is turned on. This calibration mechanism enables the system to maintain a power detection accuracy of ±5% during long-term operation, significantly improving the reliability and consistency of the product, especially suitable for commercial IH equipment scenarios where cookware needs to be frequently replaced.

[0069] The present invention is not limited to the above optional implementation manners. Anyone can obtain other various forms of products under the inspiration of the present invention. The above specific implementation manners should not be construed as limiting the protection scope of the present invention. The protection scope of the present invention should be defined by the claims, and the description can be used to interpret the claims.

Claims

1. A system for determining the type of induction cooker pots based on a chip with built-in PGA, characterized in that: include: The current sampling module includes a sampling resistor R, which is used to collect the pulse current signal of the power circuit when the IGBT is switched, and convert the current signal into a small voltage signal; The signal amplification module is a differential PGA built into the chip, which is used to select the built-in bias voltage Verf, amplify the small voltage signal by a specified multiple, and output the amplified signal; The signal processing module includes an ADC module and a comparator module. The ADC module converts the amplified analog current signal into a digital variable for power calculation and control reference. The comparator module sets comparison reference voltages VDAC1 and VDAC2 to monitor whether the amplified signal exceeds the range and outputs a flip signal when it exceeds the range. The counting module is a counter inside the CPU, which receives the flip signal and counts; The judgment module judges the type of cookware and matches the control power according to the counter value in unit time and the count value curve characteristics of different power points in the entire controllable power range.

2. The system according to claim 1, characterized in that: The differential PGA adopts a differential input structure and uses Verf as a bias reference to amplify the differential small voltage signal output by the sampling resistor R. The amplification factor is configurable to meet the amplification requirements of the current signal in different power scenarios.

3. The system according to claim 1, characterized in that: The comparator module includes one or more comparators. The comparator reference voltages VDAC1 and VDAC2 are generated by the built-in DAC module of the chip. VDAC1 is set as the signal upper threshold, and VDAC2 is set as the signal lower threshold. When the PGA output signal exceeds VDAC1 or is lower than VDAC2, the comparator flips and triggers the counting module.

4. The system according to claim 1, characterized in that: The ADC module collects the PGAOUT voltage through hardware triggering when the IGBT is turned on, converts the analog signal into a digital quantity, and outputs it to the built-in digital comparator; the digital comparator sets the comparison upper and lower limits, and the comparison result is used to control the counting of the counting module.

5. The system according to claim 1, characterized in that: The system also includes a power control module. The judgment module calls a pre-stored power control strategy according to the identified type of cookware, and adjusts the switching parameters of the IGBT through the power control module to achieve power output that is suitable for the cookware.

6. A method for determining the type of induction cooker based on a chip with built-in PGA, applied to the system according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step S1: Current signal acquisition, the pulse current of the power circuit when the IGBT is switched is collected through the sampling resistor R, and converted into a small voltage signal to input into the built-in differential PGA of the chip; Step S2: signal amplification, the differential PGA selects the Verf bias voltage, amplifies the small voltage signal, and outputs it to the ADC module and the comparator module; Step S3: signal processing, the ADC module converts the amplified signal into a digital variable; the comparator module determines whether the signal is out of range through VDAC1 and VDAC2, and outputs a flip signal when it is out of range; Step S4: counting, the internal counter of the CPU counts the flip signal and records the count value per unit time; Step S5: Cookware determination: within the controllable power range of the product, obtain the unit time count values ​​at different power points, generate a count value curve, and determine the cookware type based on the curve characteristics.

7. The method according to claim 6, characterized in that: In step S2, the amplification factor of the differential PGA is dynamically adjusted according to the preset power range of the system, a high amplification factor is selected in a low-power scenario, and a low amplification factor is selected in a high-power scenario, so as to ensure that the signals input to the ADC and the comparator module are in the effective detection range.

8. The method according to claim 6, characterized in that: In the step S3, the VDAC1 and VDAC2 voltage values ​​of the comparator module are pre-calibrated and set according to the C-pole voltage characteristics when the IGBT is turned on; when the IGBT is turned on when the C-pole voltage is higher, the positive high-frequency pulse current is easily triggered by amplification. VDAC1; when the IGBT is turned on when the C-pole voltage is lower than the ground voltage, the negative high-frequency pulse current is easily triggered by amplification.

9. The method according to claim 6, characterized in that: In step S5, standard count value curves of various types of cookware are pre-stored, and the type of cookware is determined by calculating the matching degree between the current count value curve and the standard curve; the matching degree calculation includes dimensions such as curve shape similarity, mean difference of count values ​​per unit time, and difference in distribution characteristics of power point count values.

10. The method according to claim 6, characterized in that: It also includes a system calibration step: after the system is initialized or key components are replaced, standard cookware is tested to collect count values ​​at different power points, generate a calibration curve and update system parameters to ensure cookware identification accuracy.

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