A method, device and system for detecting air pressure of intelligent protective pad

Abstract

The present application relates to the field of air pressure detection technology, and specifically to an air pressure detection method, device and system for an intelligent protective pad, the method comprising: obtaining the air pressure data collected by each pressure sensor and the temperature data collected by each temperature sensor at each collection time within the collection cycle of the current moment; determining the time domain weight and preliminary correction of the air pressure at each collection time based on the average level of the difference of all temperature data collected by each temperature sensor within the collection cycle, and the similarity between all air pressure data collected by each pressure sensor and all air pressure data collected by all other pressure sensors; and calculating the corrected real-time air pressure at the current moment to achieve air pressure measurement inside the airbag of the intelligent protective pad. The present application aims to effectively eliminate the pressure measurement error caused by the instability of the fluid environment inside the airbag, and achieve high-precision measurement of the air pressure of the intelligent protective pad.

Description

Technical Field

[0001] The present application relates to the field of air pressure detection technology, and in particular to an air pressure detection method, device and system for an intelligent protective pad. Background Art

[0002] During the long-term continuous contact between the user and the hard object, due to the severe or continuous pressure or pressure combined with shear force, local damage to the skin contact area or potential subcutaneous soft tissue occurs, which manifests as local tissue damage but intact epidermis or open ulcers, and may be accompanied by pain, often manifested as pressure injury of the patient's sacral and coccygeal skin.

[0003] At present, most of the prevention of sacral skin pressure injuries is done by using flat blanket-type soft pads such as sponge pads and gel pads to pad the sacral region of patients. The smart protective pad is a hollow annular airbag-shaped air cushion that obtains the air pressure inside the airbag through a built-in pressure sensor to evaluate the pressure state of the contact surface.

[0004] The common piezoresistive sensors currently have poor dynamic durability. When the temperature and humidity of the environment in which the protective pad is located changes, it is impossible to accurately capture the air pressure state signal, which is not conducive to accurately responding to the pressure of the contact area of ​​the protective pad for a long time. At the same time, when the object protected by the smart protective pad is an object that can move by itself, the movement of the object will cause gas flow inside the airbag of the protective pad, and the gas flow will cause the air pressure measured by the sensor inside the airbag to change in value. This change in air pressure value cannot reflect the static pressure of the fluid environment inside the airbag, thereby causing air pressure detection errors. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of this application is to provide an air pressure detection method, device and system for an intelligent protective pad. The technical solutions adopted are as follows:

[0006] In the first aspect, the embodiment of the present application provides an air pressure detection method of an intelligent protection pad, which is used to measure the air pressure in the airbag of the intelligent protection pad. The air pressure detection method is implemented by an air pressure detection device 1, and the air pressure detection device 1 includes an airbag 11, a sensor group 12 composed of a piezoresistive pressure sensor and a temperature sensor, and a main control chip 13. The sensor group 12 is evenly installed in the airbag 11. The air pressure detection method includes the following steps:

[0007] A1, obtaining the air pressure data collected by each pressure sensor and the temperature data collected by each temperature sensor at each collection time in the collection cycle at the current time;

[0008] A2, based on the changes in the air pressure data and temperature data in the current collection cycle, measure the air pressure in the airbag of the smart protection pad, specifically:

[0009] A21, determining the temperature change intensity of the corresponding temperature sensor based on the average level of the difference of all temperature data collected by each temperature sensor within the collection period;

[0010] A22, determining the airflow stability of the corresponding pressure sensor based on the similarity between all the air pressure data collected by each pressure sensor and all the air pressure data collected by all other pressure sensors;

[0011] A23, the airflow stability of all pressure sensors in the acquisition cycle and the temperature change intensity of all temperature sensors are integrated as the airbag environment stability at the current moment; the airbag environment stability and temperature vector of all acquisition moments in the acquisition cycle of the current moment are obtained; the time domain weight of each acquisition moment is determined by combining the mean value of the temperature vector and the airbag environment stability;

[0012] A24, using the data of reverse fusion of the airflow stability and temperature change intensity of each group of sensors at each collection moment as weights, weighting the air pressure data measured in the corresponding group of sensors, and determining the initial corrected air pressure at each collection moment;

[0013] A25, combining the time domain weight and the preliminary corrected air pressure, calculates the corrected real-time air pressure at the current moment, and realizes the air pressure measurement inside the airbag of the smart protection cushion.

[0014] Preferably, the method for determining the intensity of temperature change is: differentiating all temperature data collected by each temperature sensor in order of collection time, and taking the average level of the absolute values ​​of all differential values ​​as the intensity of temperature change of the corresponding temperature sensor.

[0015] Preferably, the airflow stability is positively correlated with the minimum value of all the similarities.

[0016] Preferably, the airbag environment stability is the ratio of the sum of the airflow stabilities of all the pressure sensors to the sum of the temperature change intensities of all the temperature sensors.

[0017] Preferably, the method for determining the time domain weight is:

[0018] Calculate the difference between the mean value of the temperature vector at each acquisition moment and the mean value of the temperature vector at the current moment;

[0019] Reversely fuse the airbag environment stability at each acquisition moment with the difference to obtain a time domain weight;

[0020] The result of reverse fusion is positively correlated with the time domain weight.

[0021] Preferably, the reverse fusion method is further determined as a normalized value of the ratio of the airflow stability and the temperature change intensity of each group of sensors.

[0022] Preferably, the preliminary corrected air pressure is determined by a result of weighted summation of the measured air pressure data by the weights of each group of sensors.

[0023] Preferably, the corrected real-time air pressure is determined by taking the time domain weight as the weight and performing weighted summation on the preliminary corrected air pressure at the corresponding acquisition moment.

[0024] In the second aspect, an embodiment of the present application provides an air pressure detection device for an intelligent protective pad, including an airbag 11, a sensor group 12 consisting of a piezoresistive pressure sensor and a temperature sensor, and a main control chip 13, wherein the main control chip 13 executes the steps of the air pressure detection method for the intelligent protective pad.

[0025] In a third aspect, an embodiment of the present application further provides an air pressure detection system of an intelligent protection pad, which implements the air pressure monitoring method of the intelligent protection pad, and the air pressure detection system includes:

[0026] The airbag data acquisition module is used to obtain the air pressure data collected by each pressure sensor and the temperature data collected by each temperature sensor at each acquisition time within the acquisition cycle at the current time;

[0027] The air pressure detection module is used to measure the air pressure in the airbag of the smart protection pad based on the changes in the air pressure data and temperature data in the collection cycle at the current moment.

[0028] It can be seen from the above embodiments that the air pressure detection method, device and system of the smart protective pad provided in the embodiments of the present application have at least the following beneficial effects:

[0029] In order to solve the problem that the pressure sensor measurement results may have errors due to the unstable fluid environment inside the airbag of the smart protection pad, this embodiment proposes an air pressure detection method for the smart protection pad, including: calculating the temperature change intensity for the time series changes of the temperature at different sensor positions in the airbag of the smart protection pad to characterize the severity of the temperature change at the sensor position, and assigning a lower confidence level to the pressure sensor measurement results at the position with severe temperature changes to eliminate the measurement errors caused by the unstable temperature inside the airbag; further, based on the similarity between all the air pressure data collected by each pressure sensor and all the air pressure data collected by all other pressure sensors, the airflow stability of the corresponding pressure sensor is determined to analyze the airflow stability caused by the movement of the object. The air pressure measurement error caused by gas flow, and the gas flow caused by the movement of the object is the gas flow in a closed environment. When the sensor generates a measurement error due to the movement of the object, the pressure near one of the pressure sensors rises due to the gas flow, and the pressure near the other pressure sensor must drop due to the characteristics of the gas flow pressure. Based on this, the air flow stability is calculated to characterize the gas flow stability at different pressure sensor positions; further, the time domain weight is calculated at the time domain level in combination with the gas stability and temperature; at the same time, the pressure sensor measurement values ​​at the corresponding moment are combined with the air flow stability and the temperature change intensity to perform data fusion to obtain the preliminary corrected air pressure; finally, the real-time air pressure is calculated and corrected in combination with the time domain weight and the preliminary corrected air pressure to complete the air pressure measurement inside the airbag. Among them, since this embodiment analyzes the temperature change and the air pressure change, it selects the pressure sensors with stable temperature environment and air flow environment, and then corrects the pressure sensor measurement values ​​at different times, and weights and sums the air pressure measurement results in the last 1 second by the temperature difference, the obtained air pressure value can effectively eliminate the pressure measurement error caused by the instability of the fluid environment inside the airbag, thereby realizing high-precision detection of the air pressure of the smart protective pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A flowchart of a method for detecting air pressure of a smart protective pad provided in one embodiment of the present application;

[0032] Figure 2 A flow chart of measuring the air pressure in the airbag of the smart protection pad provided in one embodiment of the present application;

[0033] Figure 3A schematic diagram of an air pressure signal correction process provided by an embodiment of the present application;

[0034] Figure 4 A schematic structural diagram of an air pressure detection device for an intelligent protective pad provided in one embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the air pressure detection method, device and system of an intelligent protective pad proposed in the present application, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0036] Unless otherwise specified and limited, terms such as "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such articles or devices. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the article or device including the element. In addition, the term "and\or" used herein includes any and all combinations of one or more related listed items. All technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application.

[0037] The specific scheme of the air pressure detection method, device and system of the intelligent protection pad provided by the present application is described in detail below with reference to the accompanying drawings.

[0038] See also Figure 1 , which shows a flow chart of the steps of an air pressure detection method of an intelligent protection pad provided by an embodiment of the present application, the method comprising the following steps:

[0039] A1, obtaining the air pressure data collected by each pressure sensor and the temperature data collected by each temperature sensor at each collection time in the collection cycle at the current time.

[0040] The smart protective pad of this embodiment is a ring-shaped airbag, and N groups of sensors are evenly installed inside the airbag clockwise. Each group of sensors has a piezoresistive pressure sensor and a temperature sensor to measure the air pressure and temperature inside the airbag. In this embodiment, N is 8. In this embodiment, the piezoresistive pressure sensor is referred to as a pressure sensor.

[0041] Thus, at each acquisition moment, two vectors of length N can be obtained, one of which is the pressure vector, and each element value in the pressure vector represents the numerical value measured by the pressure sensor corresponding to the acquisition moment; the other is the temperature vector, and each element value in the temperature vector represents the numerical value measured by the temperature sensor corresponding to the acquisition moment.

[0042] In the process of measuring the air pressure of the smart protective pad, the built-in main control chip will record the data in the collection cycle of the current moment, and the data recording frequency is 100 Hz. Taking time t as the current moment, this embodiment records all the data between time t and 1 second before it at time t, and all the collection moments between time t and 1 second before it form the tth collection cycle. Finally, M air pressure vectors and M temperature vectors can be obtained in the collection cycle of the current moment, where M=100. In other embodiments, the recording frequency and collection time of the collection cycle data are set by the implementer.

[0043] It is particularly noted that since the measured value of the pressure sensor will change with the temperature, and the temperature drift of the pressure sensor is linearly related to the temperature, in this embodiment, this linear relationship adopts temperature compensation measures, and this embodiment adopts a temperature drift correction method. Among them, the temperature drift correction method is specifically:

[0044] The pressure sensor is placed in the temperature environment from -40℃ to 40℃, and a set of data is measured at every 1℃ interval. Taking temperature a as an example, the static pressure of the environment is adjusted from 40 kPa to 100 kPa, and data is recorded every 1 kPa interval, and a total of B=61 data are recorded, each data includes air pressure y and pressure sensor reading x.

[0045] Furthermore, the B-time data at temperature a are fitted with a data curve by using the least squares method with the B-time data as input. The fitting model is a 4th-order polynomial, and the output is the fitting function Among them, the least squares fitting method is a well-known technology and will not be described in detail.

[0046] This embodiment measures A groups of data at intervals of 1°C from -40°C to 40°C, and finally obtains A fitting functions, A=81. The ath fitting function It represents that at temperature a, when the pressure sensor reading is x, the air pressure is .

[0047] In actual temperature measurement, the temperature measured at the nth temperature sensor position at time t in this embodiment is , the pressure sensor reading is , at this time, first set the pressure sensor reading Substituting A=81 fitting functions, we get A air pressure magnitudes and corresponding temperatures, forming a coordinate point set containing 81 coordinates, where the horizontal axis is air pressure and the vertical axis is temperature.

[0048] Furthermore, the coordinate point set containing 81 coordinates is calculated using an interpolation algorithm. In this embodiment, a mean interpolation algorithm is used to obtain the function Finally, the temperature Substitute into the function , complete the temperature drift correction and eliminate the pressure sensor measurement error caused by temperature drift.

[0049] In this embodiment, A=81 fitting functions are stored in the main control chip. When the main control chip obtains the reading of the pressure sensor, the air pressure inside the airbag of the intelligent protection pad monitored by the pressure sensor is calculated according to the above-mentioned temperature drift correction method, thereby forming the air pressure vector at each collection moment in the collection cycle at the current moment.

[0050] At this point, the pressure vector and temperature vector at each collection moment in the collection cycle at the current moment can be obtained through the above method. Each element in each pressure vector is the air pressure inside the airbag of the smart protection pad monitored by the corresponding pressure sensor, and each element in each temperature vector is the temperature inside the airbag of the smart protection pad monitored by the corresponding temperature sensor.

[0051] A2, based on the changes in the air pressure data and temperature data in the current collection cycle, measure the air pressure in the airbag of the smart protection cushion.

[0052] For N pressure sensors, since they exist in the same fluid environment, when the fluid environment is stable, the gravity effect can be ignored due to the small height difference of the fluid, and the air pressure at different sensor locations can be determined to be equal. However, when the object protected by the smart airbag self-heats, or the object moves on the protective pad, the fluid environment inside the airbag will become unstable, which will lead to measurement errors in the pressure sensor.

[0053] This embodiment performs correction calculation on the signals of N sensors due to the self-heating of the object protected by the smart airbag and the movement of the object on the protection pad to ensure the accuracy of the air pressure measurement in the airbag of the smart protection pad. Figure 2 As shown, specifically:

[0054] A21, based on an average level of differences of all temperature data collected by each temperature sensor within a collection period, determine a temperature change intensity of the corresponding temperature sensor.

[0055] For the value change of the pressure sensor caused by temperature, the temperature change can be extracted by the temperature sensor in the same group of sensors, and the temperature interference characteristics can be calculated to eliminate the influence of temperature on the reading of the pressure sensor in the same group of sensors, and complete the accurate measurement of the air pressure in the airbag of the smart protection cushion. The specific method is as follows:

[0056] The temperature drift of the pressure sensor is linearly related to the temperature. This embodiment uses this linear relationship to take temperature compensation measures to complete temperature correction. When the temperature is relatively stable, the reading of the pressure sensor is less affected by the temperature; when the protected object in the smart protection pad is used as a heat source, the air temperature inside the airbag is in a changing state.

[0057] When the temperature around the pressure sensor changes too drastically, the temperature near the pressure sensor and the temperature near the temperature sensor differ greatly, resulting in temperature compensation failure, causing inaccurate pressure sensor measurement signals at this moment.

[0058] Therefore, this embodiment determines the temperature change intensity of the corresponding temperature sensor based on the average level of the difference of all temperature data collected by each temperature sensor within the collection period.

[0059] The method for determining the intensity of temperature change is specifically as follows: all temperature data collected by each temperature sensor are differentiated in the order of collection time, and the average level of the absolute values ​​of all differential values ​​is used as the temperature change intensity of the corresponding temperature sensor.

[0060] As an implementation method, for the M temperature vectors obtained in the collection period at time t, all n-th element values ​​are obtained, representing the temperature values ​​collected by the n-th temperature sensor at all collection times in the collection period t, and are arranged into a sequence from left to right in chronological order to form a sequence with a length of M, which is recorded as the temperature change sequence of the n-th temperature sensor;

[0061] The temperature change sequence is further obtained as a differential sequence by calculating the difference between adjacent elements of the temperature change sequence, and arranging all the differences into a sequence, which is recorded as a temperature differential sequence.

[0062] Finally, the mean of the absolute values ​​of all elements in the temperature difference sequence is recorded as the temperature interference intensity. The larger the temperature interference intensity value, the more drastic the temperature change at the nth temperature sensor position during the acquisition period, the more serious the interference to the air pressure data, and the lower the reliability of the pressure sensor's measurement signal.

[0063] A22, determining the airflow stability of the corresponding pressure sensor based on the similarity between all the air pressure data collected by each pressure sensor and all the air pressure data collected by all other pressure sensors.

[0064] When the object on the smart protection cushion is stable and motionless, the fluid environment inside the entire airbag is in a stable state. At this time, the pressures measured by pressure sensors at different positions inside the airbag are the same; when the object on the airbag moves, the gas inside the airbag will flow. At this time, the measurement data of the pressure sensor is different from the static pressure inside the object and the airbag, and the faster the gas state changes inside the airbag, the less it can objectively reflect the static pressure of the gas inside the airbag.

[0065] Usually, when an object on the airbag moves, it can be regarded as a transfer of object pressure on the airbag surface, that is, the object leaves the airbag surface at one position of the airbag and squeezes the airbag surface at another position; therefore, the pressure sensor that produces measurement deviation due to the movement of the object generally presents the characteristics of complementary changes in the measurement data of the two pressure sensors.

[0066] Therefore, according to the air pressure variation feature of the pressure sensor, the embodiment identifies the pressure sensors that are less affected by the movement of the object, and uses the data of these pressure sensors as the air pressure measurement result of the smart protective pad. The specific method is as follows:

[0067] For the acquisition cycle at the current time t, this embodiment obtains M=100 air pressure vectors, arranges the nth elements in all air pressure vectors in chronological order from left to right, and records them as the nth air pressure change sequence, which characterizes the change of data measured by the nth pressure sensor over time.

[0068] Further, the similarity of the nth air pressure change sequence with the other N-1 air pressure change sequences is calculated. If the similarity with the rth air pressure change sequence is closer to -1, it means that the air pressure measurement values ​​of the two air pressure change sequences show more complementary changes, and the air pressure measurement result at the nth pressure sensor position is more affected by the movement of the object above the protective pad, and the measurement data is less reliable.

[0069] In this embodiment, cosine similarity is used to calculate the similarity between air pressure change sequences. Cosine similarity is a well-known technology and will not be described in detail. In other embodiments of the present application, the Pearson correlation coefficient may also be used to calculate the similarity between air pressure change sequences.

[0070] Preferably, in this embodiment, the airflow stability is positively correlated with the minimum value of all the similarities.

[0071] It can be understood that a positive correlation means that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases. This is determined by actual application and is not specifically limited in this application.

[0072] As an implementation method, for the N-1 cosine similarities of the nth air pressure change sequence, the smallest cosine similarity is selected and recorded as the nth complementary change strength. Further, the N complementary change strengths are non-negatively processed by:

[0073] The nth complementary change intensity is added with 1 to complete the non-negative processing, which is recorded as the nth airflow stability. It should be understood that the greater the airflow stability, the more stable the airflow at the nth pressure sensor at time t, and the more reliable the air pressure measurement result.

[0074] A23, fuses the airflow stability of all pressure sensors within the acquisition cycle with the temperature change intensity of all temperature sensors as the airbag environment stability at the current moment; obtains the airbag environment stability and temperature vector of all acquisition moments within the acquisition cycle of the current moment; combines the mean value of the temperature vector and the airbag environment stability to determine the time domain weight of each acquisition moment.

[0075] For the smart protective pad, the gas environment inside the airbag will change due to the temperature and movement of the object carried, and an unstable internal gas environment will cause errors in air pressure detection. Therefore, this embodiment calculates the time domain weight to filter out the moment when the internal environment of the airbag is stable, thereby calculating the air pressure inside the airbag. The specific method is:

[0076] In this embodiment, the airflow stability of all pressure sensors and the temperature change intensity of all temperature sensors within the acquisition period are integrated as the airbag environment stability at the current moment.

[0077] Preferably, in the current collection period, N temperature change intensities and N airflow stabilities can be calculated for N groups of sensors. Furthermore, in this embodiment, the ratio of the sum of the N airflow stabilities to the sum of the N temperature change intensities is recorded as the airbag environment stability at the current moment. The larger the value, the more stable the internal environment of the airbag at the current moment.

[0078] Optionally, in other embodiments, the accumulated result of the ratio of the airflow stability to the temperature change intensity of all corresponding sensor groups may be recorded as the airbag environment stability at time t.

[0079] Furthermore, this embodiment obtains the airbag environment stability and temperature vector at all acquisition moments in the acquisition cycle where the current moment is located, that is, for the measurement data within 1 second before the current moment t and its acquisition cycle, the data of the stable internal environment of the airbag is screened out to calculate the pressure on the airbag of the current smart protection pad. The specific method is:

[0080] The data of the past 1 second corresponds to the data of the collection time recorded M times, and the data of the collection time recorded each time is used as the last collection time of the collection cycle, that is, M collection cycles are obtained. In this embodiment, the main control chip obtains the M airbag environmental stability and M temperature vectors calculated corresponding to the collection cycle of the M collection times including time t. Furthermore, the M temperature vectors are averaged respectively, and the mth average is recorded as the mth average temperature, which represents the internal temperature of the airbag corresponding to time m. Among them, .

[0081] Furthermore, this embodiment combines the mean value of the temperature vector and the airbag environment stability to determine the time domain weight of each acquisition moment.

[0082] Preferably, the method for determining the time domain weight is: calculating the difference between the mean of the temperature vector at each acquisition moment and the mean of the temperature vector at the current moment; reversely fusing the airbag environmental stability at each acquisition moment with the difference to obtain the time domain weight; wherein the result of reverse fusion is positively correlated with the time domain weight.

[0083] It can be understood that reverse fusion is a fusion method such as subtraction and division between data. The specific reverse fusion method is determined by the implementer according to the actual situation, and this application does not impose any special restrictions.

[0084] As an implementation method, the absolute value of the difference between the Mth average temperature and the mth average temperature is calculated; the mth airbag environmental stability is divided by the sum of the mth absolute value and the constant z to obtain the mth time domain credibility; the proportion of the mth time domain credibility in the sum of M time domain credibility is used as the mth time domain weight.

[0085] Optionally, in other embodiments, the difference may be replaced by the distance between the temperature vector at each acquisition moment and the temperature vector at the current moment, and the airbag environment stability at each acquisition moment may be reversely fused with the difference.

[0086] It should be understood that the smaller the difference between the mth average temperature and the Mth average temperature, the smaller the difference between the internal environment of the airbag at the mth moment and the internal environment of the airbag at the current moment, and the more appropriate it is to use the data at the mth moment to estimate the current air pressure; where the constant z is a very small number to prevent the denominator from being 0, and is taken as 0.01 here. At this time, the greater the stability of the airbag environment, the more stable the airflow movement inside the airbag at the corresponding moment, and the more reliable the pressure sensor measurement result at the corresponding moment.

[0087] Ultimately, the larger the time domain weight is, the more reliable it is to estimate the internal air pressure of the airbag at the current moment through the pressure sensor measurement result at the mth moment.

[0088] A24 uses the data of reverse fusion of the airflow stability and temperature change intensity of each group of sensors at each collection moment as weights, weights the air pressure data measured in the corresponding group of sensors, and determines the initial corrected air pressure at each collection moment.

[0089] Finally, this embodiment corrects the air pressure data in the airbag at the current moment through the relevant data, and the method is:

[0090] In the collection period at the mth moment, N temperature change intensities and N airflow stabilities are obtained.

[0091] Preferably, the reverse fusion method is: the ratio of the airflow stability of the nth group of sensors to the temperature change intensity is used as the environmental stability of the nth group of sensors, and the larger the value, the more stable the environment at the location of the nth group of sensors. The preliminary corrected air pressure is determined by the weighted sum of the measured air pressure data by the weights of each group of sensors.

[0092] Furthermore, as an implementation mode, at the mth moment, a total of N environmental stabilities are obtained for N groups of sensors, and the N environmental stabilities are normalized respectively, by summing the N environmental stabilities, and then dividing the sum by the nth environmental stability to obtain the position weight of the nth group of sensors.

[0093] It should be understood that the greater the position weight of the nth group of sensors, the more stable the temperature and airflow environment of the nth group of sensors at the mth moment is compared with the positions of other groups of sensors, and the more reliable its air pressure measurement result is.

[0094] Further, the position weight of the group of sensors is used as the weight, and the air pressure data measured by the corresponding group of sensors at the mth moment are weighted and summed to obtain the initial corrected air pressure at the mth moment, which represents the overall measurement value of the pressure sensor at the mth moment.

[0095] A25, combining the time domain weight and the preliminary corrected air pressure, calculates the corrected real-time air pressure at the current moment, and realizes the air pressure measurement inside the airbag of the smart protection cushion.

[0096] Furthermore, the preliminary corrected air pressures at M moments are weighted and summed with the time domain weight as the weight to obtain the corrected real-time air pressure at the current moment, which represents the air pressure inside the airbag at the current moment.

[0097] Among them, the time domain weight is used to give a higher weight to the preliminary corrected air pressure that is similar to the current temperature and whose overall measurement value of the pressure sensor is credible. The current air pressure is estimated by the pressure sensor measurement value in the past 1 second, which can effectively reduce the influence of temperature and object movement on air pressure measurement.

[0098] At this point, the air pressure measurement of the smart protection pad is completed.

[0099] In summary, since this embodiment analyzes the temperature changes and air pressure changes, selects the pressure sensors with stable temperature and airflow environments to correct the measurement values ​​of the pressure sensors at different times, and weightedly sums the air pressure measurement results within the last second by the temperature difference, the obtained air pressure value can effectively eliminate the pressure measurement error caused by the unstable fluid environment inside the airbag, and can obtain a more accurate pressure measurement result.

[0100] In this embodiment, the schematic diagram of the air pressure signal correction process is as follows: Figure 3 As shown, in the air pressure signal correction process of the present embodiment, the air pressure signal acquisition data is corrected for temperature drift through the readings of the pressure sensor and the temperature sensor; the air pressure signal acquisition data after temperature drift correction is further calculated by the main control chip according to the method described in the second step of the present embodiment to obtain the final corrected real-time air pressure.

[0101] See also Figure 4 , Figure 4 Schematic diagram of the structure of an air pressure detection device of an intelligent protective pad provided in an embodiment of the present application. Figure 4 In the figure, 1 is an air pressure detection device, 11 is an airbag, 12 is a sensor group consisting of a piezoresistive pressure sensor and a temperature sensor, and 13 is a main control chip. The airbag 11 is the main part of the smart protective pad, which is composed of a ring-shaped airbag; the sensor group 12 is evenly installed in the airbag 11, wherein the piezoresistive pressure sensor and the temperature sensor contained in each sensor group 12 are placed in the same position; wherein the main control chip 13 is used to store and process air pressure measurement data.

[0102] Based on the same inventive concept as the above method, an embodiment of the present application further provides an air pressure detection system for an intelligent protection pad, wherein the air pressure detection system includes: an airbag data acquisition module and an air pressure correction module.

[0103] The airbag data acquisition module is used to obtain the air pressure data collected by each pressure sensor and the temperature data collected by each temperature sensor at each acquisition time within the acquisition cycle at the current time;

[0104] The data storage module is used to measure the air pressure in the airbag of the intelligent protection pad based on the changes in the air pressure data and temperature data in the collection cycle at the current moment.

[0105] The various embodiments in the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0106] It should be noted that, unless otherwise specified and limited, terms such as "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, an element defined by the sentence "including one..." does not exclude the existence of other identical elements in the article or device including the element. In addition, the term "and\or" used herein includes any and all combinations of one or more related listed items.

[0107] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not invented by the present application.

[0108] It will be appreciated that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A method for detecting air pressure of an intelligent protective pad, used to measure the air pressure in an airbag of the intelligent protective pad, characterized in that: The air pressure detection method is implemented by an air pressure detection device (1), the air pressure detection device (1) comprising an air bag (11), a sensor group (12) consisting of a piezoresistive pressure sensor and a temperature sensor, and a main control chip (13), the sensor group (12) being evenly installed in the air bag (11), and the air pressure detection method comprising the following steps: A1, obtaining the air pressure data collected by each pressure sensor and the temperature data collected by each temperature sensor at each collection time in the collection cycle at the current time; A2, based on the changes in the air pressure data and temperature data in the current collection cycle, measure the air pressure in the airbag of the smart protection pad, specifically: A21, determining the temperature change intensity of the corresponding temperature sensor based on the average level of the difference of all temperature data collected by each temperature sensor within the collection period; A22, determining the airflow stability of the corresponding pressure sensor based on the similarity between all the air pressure data collected by each pressure sensor and all the air pressure data collected by all other pressure sensors; A23, the airflow stability of all pressure sensors in the acquisition cycle and the temperature change intensity of all temperature sensors are integrated as the airbag environment stability at the current moment; the airbag environment stability and temperature vector of all acquisition moments in the acquisition cycle of the current moment are obtained; the time domain weight of each acquisition moment is determined by combining the mean value of the temperature vector and the airbag environment stability; A24, using the data of reverse fusion of the airflow stability and temperature change intensity of each group of sensors at each collection moment as weights, weighting the air pressure data measured in the corresponding group of sensors, and determining the initial corrected air pressure at each collection moment; A25, combining the time domain weight and the preliminary corrected air pressure, calculates the corrected real-time air pressure at the current moment, and realizes the air pressure measurement inside the airbag of the smart protection cushion.

2. The air pressure detection method of the intelligent protective pad according to claim 1, characterized in that: The method for determining the temperature change intensity is: all temperature data collected by each temperature sensor are differentiated in the order of collection time, and the average level of the absolute values ​​of all differential values ​​is used as the temperature change intensity of the corresponding temperature sensor.

3. The air pressure detection method of the intelligent protective pad according to claim 1, characterized in that: The airflow stability is positively correlated with the minimum value of all the similarities.

4. The air pressure detection method of the intelligent protection pad according to claim 1, characterized in that: The airbag environment stability is the ratio of the sum of the airflow stabilities of all the pressure sensors to the sum of the temperature change intensities of all the temperature sensors.

5. The air pressure detection method of the intelligent protection pad according to claim 4, characterized in that: The method for determining the time domain weight is: Calculate the difference between the mean value of the temperature vector at each acquisition moment and the mean value of the temperature vector at the current moment; Reversely fuse the airbag environment stability at each acquisition moment with the difference to obtain a time domain weight; The result of reverse fusion is positively correlated with the time domain weight.

6. The air pressure detection method of the intelligent protection pad according to claim 1, characterized in that: The reverse fusion method is further determined as a normalized value of the ratio of the airflow stability and the temperature change intensity of each group of sensors.

7. The air pressure detection method of the intelligent protection pad according to claim 6, characterized in that: The preliminary corrected air pressure is determined by a weighted summation of the measured air pressure data using the weights of each group of sensors.

8. The air pressure detection method of the intelligent protective pad according to claim 1, characterized in that: The corrected real-time air pressure is determined by taking the time domain weight as the weight and performing weighted summation on the preliminary corrected air pressure at the corresponding acquisition moment.

9. An air pressure detection device for an intelligent protective pad, comprising an air bag (11), a sensor group (12) consisting of a piezoresistive pressure sensor and a temperature sensor, and a main control chip (13), characterized in that: The main control chip (13) executes the steps of the air pressure detection method of the smart protective pad as claimed in any one of claims 1 to 8.

10. An air pressure detection system for a smart protective pad, implementing the air pressure monitoring method for a smart protective pad as claimed in claim 1, characterized in that: The air pressure detection system comprises: The airbag data acquisition module is used to obtain the air pressure data collected by each pressure sensor and the temperature data collected by each temperature sensor at each acquisition time within the acquisition cycle at the current time; The air pressure detection module is used to measure the air pressure in the airbag of the smart protection pad based on the changes in the air pressure data and temperature data in the collection cycle at the current moment.

Images