Zero-gap pillow height adjustment method for pressure gradient closed-loop control

Abstract

This invention discloses a zero-gap pillow height adjustment method with pressure gradient closed-loop control, relating to the field of pressure control. It utilizes data fusion from three heterogeneous sensors, introducing a consistency principle for cross-validation. Multi-dimensional fusion effectively eliminates interference from non-target signals such as limb movements and vibrations from turning over, distinguishing subtle postures like supine, side-sleeping, and side-sleeping while using a mobile phone, reducing the misjudgment rate of sleeping posture. For the different biomechanical needs of supine and side-sleeping positions, it employs differentiated adjustment strategies and zoned control to support the cervical curvature and compensate for shoulder gaps, relieving cervical pressure and arm numbness. For users of different body types and sleeping postures, it dynamically calculates the required support height using a built-in biomechanical compensation model, combined with user-inputted height, weight, shoulder width data, and real-time tilt angle.

Description

Technical Field

[0001] This invention relates to the field of pressure control, and in particular to a zero-gap pillow height adjustment method for pressure gradient closed-loop control. Background Technology

[0002] With increasing awareness of healthy sleep, a variety of smart pillows with adjustment functions have appeared on the market.

[0003] The existing technology has the following main shortcomings:

[0004] Sleep posture recognition methods are limited. Most products rely on a single pressure sensor or gyroscope to determine sleep posture, which can easily lead to misjudgment when the user moves slightly or there is external interference, resulting in incorrect pillow adjustment and affecting sleep comfort.

[0005] The adjustment strategies are simple, mostly involving only raising and lowering a single height. They cannot provide precise and differentiated zone support for the different biomechanical needs of lying down and side sleeping, making it difficult to effectively relieve cervical spine pressure or solve the problem of arm numbness due to pressure when sleeping on one's side.

[0006] Some existing smart pillows use fluid transfer in pipes to achieve height adjustment and use position detection sensors to determine whether the user is lying on their back or side. However, they have not solved the problem of accurate and interference-resistant sleeping posture recognition, nor have they fully considered the fine compensation for the gap between the shoulder and arm when sleeping on the side.

[0007] Furthermore, existing technologies mostly use inflation control methods to inflate to a set air pressure or inflation to a set time, lacking quantitative evaluation indicators for the degree of fit between the pillow surface and the neck. Due to the huge differences in weight, shoulder width and cervical curvature among different users, fixed inflation parameters often result in either insufficient support or over-inflation.

[0008] Therefore, we propose a zero-gap pillow height adjustment method with pressure gradient closed-loop control to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide a zero-gap pillow height adjustment method for pressure gradient closed-loop control, so as to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a zero-gap pillow height adjustment method for pressure gradient closed-loop control, comprising the following steps:

[0011] S1: Initialization and status monitoring, completes system hardware self-test and enters standby state, and monitors the pressure data of the user's head and neck acting on the pillow surface in real time;

[0012] S2: Multi-source sleeping posture determination, collecting at least two types of sensor data including head and neck pressure distribution, head spatial posture and status of associated electronic devices to determine the current sleeping posture;

[0013] S3: Pattern matching and execution. Based on the determined sleeping posture, the corresponding airbag adjustment strategy is matched. The adjustment strategy includes at least the supine zero-gap mode, the side-sleeping anti-pressure mode, and the forward-tilting support mode.

[0014] S4: Pressure gradient closed-loop control. During the adjustment process, the pressure gradient value of the shoulder and neck support area is calculated in real time. The inflation and deflation volume and rate of the airbag are dynamically adjusted through the closed-loop control algorithm until the pressure gradient value converges to the preset comfort threshold range, so as to achieve dynamic zero-gap fit between the pillow surface and the shoulder and neck area.

[0015] Preferably, based on the system hardware self-test in step S1, it includes:

[0016] Impedance-capacitance combined detection is performed on a flexible pressure sensor array to determine the circuit continuity and short circuit status.

[0017] The air passage unobstructedness and air tightness of the airbag inflation / deflation actuator are tested. The air tightness test is achieved by inflating the airbag to the preset pressure, letting it stand, and monitoring the pressure drop.

[0018] Preferably, the multi-source sleeping posture determination in step S2 specifically includes:

[0019] First data collection: The three-axis accelerometer and gyroscope collect pitch angle, roll angle and angular velocity data of the head's spatial attitude;

[0020] Second data acquisition: A flexible pressure sensor array acquires pressure values ​​and two-dimensional spatial location information;

[0021] Third data acquisition: The wireless communication module acquires the screen orientation and relative position change trends of the associated electronic devices;

[0022] When at least two types of data meet the preset sleeping posture characteristics and continue for more than the set time, the sleeping posture status is confirmed to be valid.

[0023] Preferably, based on step S2, the sleeping posture includes supine posture, side-lying anti-pressure posture, and side-lying posture for looking at a mobile phone.

[0024] The supine position must meet the following conditions simultaneously: the center of pressure is located in the center of the pillow surface, there is no rolling over event, and the screen of the associated electronic device is in portrait mode or off.

[0025] The criteria for determining a side-sleeping anti-pressure posture are: the center of pressure is off-center from the pillow surface and the proportion of pressure on one side exceeds the threshold, and there is a rolling over event.

[0026] To determine whether someone is looking at their phone while lying on their side, the following conditions must be met: the center of gravity is located on one side with a forward tilt, and the screen of the connected electronic device is in landscape mode.

[0027] Preferably, the sleeping posture state fusion determination involves inputting the first data, the second data, and the third data into the local decision unit, using a rule-based multi-source information fusion algorithm to determine the sleeping posture, and outputting the current user's sleeping posture state.

[0028] Preferably, when the sleeping position is determined to be supine, the supine zero-gap mode is triggered to perform zero-gap adjustment. If any of the first, second, and third data is not met, the position is determined to be non-supine, the zero-gap adjustment is paused, and the corresponding sleeping position mode is switched.

[0029] When the sleeping position is determined to be side sleeping, the corresponding side sleeping anti-pressure mode is triggered to reduce pressure. If the phone is switched to landscape mode, it is determined to be a side sleeping position for looking at the phone, the current adjustment is paused and the corresponding mode is switched.

[0030] When the user is identified as sleeping on their side while looking at their phone, the corresponding "Sleeping on the side while looking at your phone" mode is triggered to perform frontal compensation adjustments. The phone is switched to portrait mode or turned off, the current adjustment is paused, and the user is switched to the "Sleeping on the side to prevent pressure" mode.

[0031] Preferably, the calculation of the pressure gradient value of the shoulder and neck support area based on step S4 specifically includes:

[0032] The collected pressure data is denoised and normalized.

[0033] Divide the area corresponding to the shoulder and neck, calculate the ratio of the pressure difference between any two adjacent pressure sampling points in the area to the distance between the two points, and take the average value of the gradients of all adjacent points as the real-time average pressure gradient value.

[0034] Preferably, the condition is determined to be a supine position and the supine zero-gap mode is triggered, specifically including:

[0035] The system identifies low-pressure gaps in the area corresponding to the cervical spine, calculates the required filling height, and drives at least one set of airbags in the central axis area of ​​the pillow to inflate and lift until the pressure sensor feedback shows that the pressure in that area has reached a preset threshold.

[0036] Preferred options include the following: Side-sleeping anti-pressure mode

[0037] The system retrieves the user's physiological parameters and real-time tilt angle, calculates the required elevation height of the spine using a biomechanical compensation model, performs micro-deflation of the pressure side airbag and gradient micro-inflation of the support side airbag, and performs asymmetrical inflation to form an asymmetrical transition slope from the head to the shoulder.

[0038] Preferably, after the adjustment reaches the zero-gap state:

[0039] Lock in the current airbag pressure and collect pressure gradient data in the shoulder and neck area;

[0040] If the average pressure gradient in the neck and shoulder exceeds the threshold and remains there for a set time, restart the PID control for micro-inflation adjustment.

[0041] When a change in sleeping position is detected, the current adjustment is paused and the corresponding mode is switched.

[0042] The technical effects and advantages of this invention are as follows:

[0043] 1. By fusing data from three heterogeneous sensors and introducing the consistency principle for cross-validation, the multi-dimensional fusion judgment effectively eliminates interference from non-target signals such as limb movements and turning over vibrations, distinguishes subtle postures such as lying on one's back, sleeping on one's side, and lying on one's side while looking at a mobile phone, reduces the misjudgment rate of sleeping posture, and avoids incorrect adjustment caused by the failure or interference of a single sensor.

[0044] 2. To address the different biomechanical needs of supine and lateral sleeping positions, a differentiated adjustment strategy and zoned control are adopted. Pressure gradient is introduced as a quantitative evaluation index of fit, replacing the traditional single air pressure threshold. By calculating the pressure change rate of adjacent points in the shoulder and neck area, suspended and compressed areas are identified. The inflation and deflation of the airbag are dynamically fine-tuned to converge the pressure gradient to the ideal range, ensuring that the pillow surface conforms to the physiological curve of the neck, providing support for the cervical curvature and compensating for the gap between the shoulders, thereby relieving cervical pressure and arm numbness.

[0045] 3. For users of different body types and different sleeping positions, the built-in biomechanical compensation model, combined with the user's input height, weight, shoulder width data and real-time tilt angle, dynamically calculates the required support height. In side sleeping mode, the asymmetrical inflation and deflation form a smooth transition slope, which effectively compensates for the lateral bending of the head and neck caused by the thickness of the shoulder, and solves the pain points of uneven cervical spine stress and upper arm numbness due to pressure when sleeping on the side.

[0046] 4. All sensors, calculations, and controls are completed locally on the pillow, eliminating the need to upload sleep data to the cloud or rely on a mobile app for real-time processing. This protects user privacy while enabling rapid detection and adjustment responses.

[0047] 5. By limiting the airbag's lifting speed and adopting a gradual micro-inflation strategy, combined with the soundproof chamber design of the air pump, the adjustment process is ensured to be extremely smooth, almost imperceptible to the user, and will not wake up light sleepers. The setting of a single inflation time limit and the automatic air lock function in case of power failure eliminate the risk of air pump overheating and safety hazards. Attached Figure Description

[0048] Figure 1 This is a flowchart of the method of using the present invention;

[0049] Figure 2 This is a flowchart of the initialization and status monitoring process of this invention;

[0050] Figure 3This is a flowchart of the multi-source sleeping posture determination process of the present invention;

[0051] Figure 4 This is a flowchart of the pressure data acquisition and preprocessing process of the present invention;

[0052] Figure 5 This is a flowchart of the pressure gradient determination process of the present invention;

[0053] Figure 6 This is a schematic diagram of the pillow structure of the present invention;

[0054] Figure 7 This is a schematic diagram of the pillow of the present invention disassembled;

[0055] Figure 8 This is a schematic diagram of the pillow body structure of the present invention.

[0056] In the diagram: 1. Pillow body; 11. Independent groove; 12. Central groove; 2. Pillow bottom shell layer; 3. Independent airbag; 4. Central auxiliary support airbag; 5. MCU control unit; 6. Control box. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] This invention provides, for example Figure 1 - Figure 8 The zero-gap pillow height adjustment method for pressure gradient closed-loop control, as shown, includes the following steps:

[0059] S1: Initialization and status monitoring, completes system hardware self-test and enters standby state, and monitors the pressure data of the user's head and neck acting on the pillow surface in real time;

[0060] S2: Multi-source sleeping posture determination, collecting at least two types of sensor data including head and neck pressure distribution, head spatial posture and status of associated electronic devices to determine the current sleeping posture;

[0061] S3: Pattern matching and execution. Based on the determined sleeping posture, the corresponding airbag adjustment strategy is matched. The adjustment strategy includes at least the supine zero-gap mode, the side-sleeping anti-pressure mode, and the forward-tilting support mode.

[0062] S4: Pressure gradient closed-loop control. During the adjustment process, the pressure gradient value of the shoulder and neck support area is calculated in real time. The inflation and deflation volume and rate of the airbag are dynamically adjusted through the closed-loop control algorithm until the pressure gradient value converges to the preset comfort threshold range, so as to achieve dynamic zero-gap fit between the pillow surface and the shoulder and neck area.

[0063] The hardware initialization process starts the flexible pressure sensor array, MCU control unit and airbag inflation / deflation actuator built into the pillow to perform a self-test. It checks whether the flexible pressure sensor array is working properly, whether the air path of the airbag inflation / deflation actuator composed of a micro air pump, solenoid valve group and air pressure sensor is unobstructed, and whether the airbag is airtight. When the self-test is passed, it enters the standby state.

[0064] Based on the system hardware self-test in step S1, it includes:

[0065] Impedance-capacitance combined detection is performed on a flexible pressure sensor array to determine the circuit continuity and short circuit status.

[0066] The air passage unobstructedness and air tightness of the airbag inflation / deflation actuator are tested. The air tightness test is achieved by inflating the airbag to the preset pressure, letting it stand, and monitoring the pressure drop.

[0067] Specifically, the system performs a hardware self-test, activating the flexible pressure sensor array built into the pillow, the MCU control unit, and the airbag inflation / deflation actuator for self-testing:

[0068] Flexible pressure sensor array detection: By applying a 1kHz AC excitation signal to the sensor using the impedance-capacitance joint detection method, the circuit impedance change and parasitic capacitance are measured to determine whether there is an open circuit or short circuit.

[0069] Airflow patency test: Control the micro air pump to run at low speed for 0.5s, monitor whether the air pressure sensor feedback value rises by ≥0.1kPa, and at the same time detect the solenoid valve switching response time;

[0070] Airbag air tightness test: Inflate the airbag to 0.5 kPa and let it stand for 5 seconds. The pressure drop is allowed to be ≤0.02 kPa. Otherwise, it is judged as an air leakage fault.

[0071] If the self-test fails, the MCU outputs a fault code via the control box LED and pushes an alarm message to the user's mobile phone via Bluetooth; if the self-test passes, it enters standby mode.

[0072] Preferably, a periodic self-diagnostic program is embedded in the MCU firmware to periodically check the working status of the pressure sensor, air pressure sensor, gyroscope, air circuit and airbag, and to provide fault codes through the color of the LED light built into the pillow, so as to facilitate users to troubleshoot the fault.

[0073] After entering standby mode, parameter initialization is performed. By retrieving the user's pre-entered personalized parameters, that is, based on the input height, weight and shoulder width data, combined with the factory-calibrated basic parameters and corresponding pressure thresholds, the pressure threshold is dynamically adjusted and initialized according to the user's weight to determine the preset pressure gradient threshold, and the initial air pressure of the airbag is set at the same time.

[0074] Specifically, when using the product for the first time, users are guided to input key physiological parameters such as height, weight, and shoulder width through a minimalist H5 page. The data is transmitted via Bluetooth and stored in the pillow's local MCU's EEPROM in an encrypted manner.

[0075] Preferably, the factory-calibrated pressure threshold default value is 0.3 kPa / cm, which is dynamically adjusted according to the user's weight. The adjustment strategy is to lower the threshold by 0.05 kPa / cm for every 10 kg increase in weight, to ensure suitability for users of different body types.

[0076] The initial air pressure of the airbag is set to 0.2 kPa to ensure that the airbag is in its initial contracted state and to avoid excessive initial height, which could cause discomfort to the user.

[0077] Pressure is monitored by a flexible pressure sensor array. When the monitored pressure does not reach the activation threshold, it is in standby mode.

[0078] When the monitored pressure reaches the activation threshold, a signal feedback is sent to identify the sleeping posture. The sleeping posture includes at least the supine position, the side-sleeping anti-pressure position, and the side-sleeping position for looking at a mobile phone. The corresponding control mode is then executed. The control modes include the supine zero-gap mode, the side-sleeping anti-pressure mode, and the side-sleeping mode for looking at a mobile phone.

[0079] Based on step S2, the synchronous acquisition of multi-source data specifically includes:

[0080] The first data representing the spatial attitude of the head is collected by a three-axis accelerometer and gyroscope embedded inside the pillow, including pitch angle, roll angle and angular velocity data.

[0081] By using a flexible thin-film pressure sensor array laid at the bottom of the pillow support layer, second data on the user's body acting on the pillow is collected, generating a pressure distribution image that includes pressure value magnitude and two-dimensional spatial location information;

[0082] The pillow uses a built-in wireless communication module, preferably a Bluetooth Low Energy module, to maintain a connection with a user-paired electronic device and acquire third data from the device, including at least the device screen orientation and the trend of relative position changes between the device and the pillow.

[0083] The sleeping posture fusion determination involves inputting the first, second, and third data into the local decision unit, using a rule-based multi-source information fusion algorithm to determine the sleeping posture, and outputting the current user's sleeping posture status. The sleeping posture status includes at least: supine posture, side-lying posture, and side-lying posture for looking at a mobile phone.

[0084] Specifically disclosed, the sleeping posture also includes the pillow-off posture. If the pressure sensor array does not reach the pressure threshold, it can be judged as the pillow-off state and put into standby mode.

[0085] Sleep posture recognition is cross-validated using data from three sensors, and pressure data is collected and preprocessed. Features are extracted from real-time multi-source data and matched with various feature templates.

[0086] I. To determine a stable supine posture, the following conditions must be met:

[0087] 1. Pressure sensor array: The frequency domain features of 1024 pressure data points are extracted by Fourier transform. The pressure centroid coordinates are located in the center of the occipital surface, which is consistent with the characteristic that the pressure is concentrated in the depression area of ​​the back of the head when lying supine, and the pressure distribution maintains this shape for more than 3 seconds.

[0088] 2.6-axis gyroscope: The time-domain integration results of the Z-axis angular velocity show no rollover event and the 3-second stabilization period has passed;

[0089] 3. Bluetooth screen status: The phone screen is in portrait orientation or / and the screen is off, consistent with the orientation of the supine position;

[0090] The MCU control unit executes a multi-dimensional threshold judgment model. When all three data points meet the supine judgment conditions and remain stable for more than 3 seconds, the supine sleeping position is determined, and the corresponding supine zero-gap mode is triggered for zero-gap adjustment. If any data point is not met, the position is determined to be non-supine, the zero-gap adjustment is paused, and the corresponding sleeping position mode is switched.

[0091] If the user is determined to be in a supine position, the zero-gap sleep mode is activated. The control unit identifies the low-pressure gap in the corresponding area of ​​the cervical spine based on the pressure distribution image, calculates the required filling height and / or curvature, and drives at least one set of airbag actuators located in the central axis area of ​​the pillow to inflate and lift the area until the pressure sensor feedback shows that the pressure in the area has reached the preset threshold, ensuring that the physiological curvature of the cervical spine is naturally supported and that the shoulders and neck fit seamlessly with the bed surface. When the pressure is within the preset threshold, it is determined that the zero-gap state has been reached, inflation is stopped, and the control solenoid valve locks in the air pressure.

[0092] II. To determine the anti-pressure sleeping posture, the following conditions must be met:

[0093] 1. Pressure sensor array: 1024 pressure data points are extracted for frequency domain features through Fourier transform. The pressure center coordinates deviate from the center of the pillow surface by more than a set threshold, which is consistent with the characteristic of pressure being concentrated in the shoulder and neck area on one side when sleeping on the side. Moreover, the proportion of pressure on one side is greater than the set threshold, and the pressure distribution maintains this pattern for more than 3 seconds.

[0094] 2.6-axis gyroscope: The time-domain integration results of the Z-axis angular velocity show that the peak angular velocity is greater than the threshold, indicating a rolling over event, and a new side-lying posture stability period of more than 3 seconds has been established;

[0095] 3. Bluetooth screen status: The phone screen is in portrait orientation or / and the screen is off, which does not conflict with the side sleeping posture;

[0096] The MCU control unit executes a multi-dimensional threshold judgment model. When all three data points meet the side-sleeping judgment conditions and remain stable for more than 3 seconds, it is determined to be a side-sleeping posture, and the corresponding side-sleeping anti-pressure mode is triggered to adjust the pressure. If the phone is detected to be in landscape mode, it is determined to be a side-sleeping posture for looking at the phone, the current adjustment is paused, and the corresponding mode is switched.

[0097] If the user is determined to be in a side-sleeping position, the side-sleeping anti-pressure mode is activated. The control unit first retrieves the user's pre-input and / or locally learned physiological parameters, and combines them with the real-time acquired tilt angle. Through a biomechanical compensation model, it calculates the height required to maintain the spine's horizontal position. The pressure-bearing side airbag performs rapid micro-deflation, while the supporting side airbag performs gradient micro-inflation, resulting in asymmetrical inflation. This creates a smooth transition slope from the head to the shoulder, compensating for the lateral bending of the head and neck caused by the shoulder protrusion, releasing pressure on the upper arm, and monitoring the contact pressure in the auricle area in real time through a flexible pressure sensor array. When the pressure on the pressure-bearing side is below the safety threshold and the height of the supporting side is adapted to the shoulder width, it is determined that the anti-pressure state has been reached, the action stops, and the solenoid valve is controlled to lock in the air pressure.

[0098] III. To determine the side-lying posture for looking at a mobile phone, the following conditions must be met:

[0099] 1. Pressure sensor array: The frequency domain features of 1024 pressure data points are extracted by Fourier transform. The pressure centroid coordinates are located on one side of the pillow surface and are accompanied by a forward tilt component, which is consistent with the head tilting forward when looking at a mobile phone while lying on the side. The pressure distribution maintains this shape for more than 3 seconds.

[0100] 2.6-axis gyroscope: The time-domain integration results of the Z-axis angular velocity show that the attitude is stable without violent overturning, and the head has a forward tilt angular velocity characteristic;

[0101] 3. Bluetooth screen status: The phone screen is in landscape orientation and the angle between the screen and the head orientation is less than the threshold, which is suitable for handheld viewing posture;

[0102] The MCU control unit executes a multi-dimensional threshold judgment model. When all three data points meet the conditions for using a mobile phone while lying on one's side and remain stable for more than 3 seconds, it is determined to be a side-lying sleeping posture for using a mobile phone. The corresponding side-lying mode for using a mobile phone is triggered to perform front compensation adjustment. If the mobile phone is switched to portrait mode or turned off, the current adjustment is paused and the side-lying anti-pressure mode is switched to.

[0103] After recognizing that the user is lying on their side while looking at their phone, the airbags on the side closer to the phone and the airbags on the side farther away from the phone are inflated in a differentiated and synchronous manner. The flexible pressure sensor array monitors the contact pressure on the front of the cervical spine in real time. When the pressure on the front side fills the suspended area and the overall pressure is within the comfort threshold, it is determined that the forward tilt support state has been reached, the inflation stops, and the solenoid valve is controlled to lock in the air pressure.

[0104] Pressure data acquisition and preprocessing involves acquiring real-time pressure distribution data in the neck and shoulder area, and then preprocessing to eliminate noise interference to ensure the accuracy of subsequent pressure gradient calculations, providing reliable feedback data for closed-loop control. Specifically:

[0105] Pressure data acquisition: The pressure distribution data of the user's head and neck against the pillow surface is collected in real time through a flexible pressure sensor array at a preset sampling frequency; the real-time air pressure data of each airbag is collected synchronously through the air pressure sensor built into the airbag at a preset sampling frequency; and the data is transmitted to the data buffer of the MCU.

[0106] Preferably, the final sleep position determination must meet the consistency principle. When the sleep position types indicated by at least two different sources are consistent, the sleep position status is confirmed to be valid; otherwise, the previous status is maintained or the status is determined to be uncertain and no adjustment is triggered.

[0107] It is particularly important to note that the flexible pressure sensor array covers the entire pillow surface, focusing on collecting pressure data in the corresponding areas of the neck and shoulders;

[0108] Based on step S4, calculating the pressure gradient value of the shoulder and neck support area specifically includes the following steps:

[0109] I. Pressure Data Preprocessing:

[0110] 1. Noise reduction: A moving average filtering algorithm is used to eliminate random noise during the sensor acquisition process;

[0111] 2. Normalization processing: Normalize the pressure data to a preset range to eliminate the pressure value differences caused by the weight differences of different users, so as to facilitate the uniform calculation of pressure gradient;

[0112] 3. Region segmentation: Coordinate positioning is performed using a flexible pressure sensor array to segment the area corresponding to the shoulder and neck, and pressure data within this area is extracted for subsequent gradient calculation.

[0113] 2. Gradient calculation: By quantifying the uniformity of pressure distribution in the neck and shoulder area, the degree of fit between the pillow surface and the neck and shoulders is determined. The smaller the pressure gradient, the tighter the fit and the better the zero-gap effect. The larger the pressure gradient, the more likely there is a gap, which needs to be adjusted.

[0114] The pressure gradient is calculated by taking the average of the gradients of all adjacent points within the shoulder and neck region, which is the ratio of the pressure difference between any two adjacent pressure sampling points to the distance between the two points.

[0115] Specifically disclosed is the biomechanical compensation model for compensating for shoulder height when lying on one's side, keeping the head and spine horizontal, and avoiding pressure on the upper arm:

[0116]

[0117] in, W represents the desired lifting height; H represents the user's weight; and W represents the user's height. For real-time roll angle , , is the experimental calibration coefficient; C is the compensation constant.

[0118] The MCU calls the pressure gradient calculation algorithm to calculate the pre-processed shoulder and neck area pressure data, obtain the real-time average pressure gradient, and compare it with the preset threshold to determine the current fit status.

[0119] If pressure data is missing during the calculation process, the adjustment will be paused immediately while maintaining the current airbag pressure to avoid discomfort caused by adjustment failure.

[0120] The average pressure gradient in the neck and shoulders is compared with the preset pressure to determine whether to continue adjusting, ensuring the adjustment process is controllable and achieving a zero-gap effect while avoiding the pressure caused by over-inflation. The specific process is as follows:

[0121] 1. If the average pressure gradient of the neck and shoulders is less than the preset pressure threshold, the pressure distribution in the neck and shoulders area is uniform, and the pillow surface has achieved zero-gap contact with the neck and shoulders, there is no need to continue inflating. Stop inflating and lock in the air pressure.

[0122] 2. If the average pressure gradient of the shoulder and neck is greater than or equal to the preset pressure threshold, there is uneven pressure in the shoulder and neck area and there is a gap. It is necessary to continue to inflate and adjust. The airbag inflation and deflation actuator will inflate and deflate the corresponding airbag, and monitor the airbag pressure at the same time to prevent overpressure.

[0123] Specifically disclosed, through PID closed-loop control, the airbag inflation volume and inflation speed are accurately calculated to avoid over-inflation or failure to reach zero gap during the adjustment process, ensuring a smooth adjustment process and improving user comfort;

[0124] During the adjustment process, the MCU will dynamically fine-tune the preset threshold based on the user's real-time pressure data to adapt to the slight changes in posture during the user's sleep, avoiding adjustment deviations caused by fixed thresholds.

[0125] According to the PID control command, the airbag inflation operation is executed, gradually raising the pillow height and reducing the gap between the shoulders and neck and the pillow, moving closer to a zero-gap state.

[0126] Specifically disclosed: PID closed-loop control for inflation:

[0127] Proportional term: Adjusts the inflation volume based on the deviation between the current gradient and the threshold;

[0128] Integral term: Eliminates steady-state error and ensures gradient convergence to within 0.05 kPa / cm;

[0129] Differential term: Suppress inflation overshoot and control lifting speed ≤5mm / s.

[0130] Specifically, the MCU sends control commands to start the micro air pump, open the solenoid valve of the corresponding airbag, and slowly inflate the airbag according to the inflation time and speed determined by PID calculation. During inflation, the airbag's built-in pressure sensor collects the airbag pressure data in real time and feeds it back to the MCU. If the air pressure exceeds the safety threshold, the air pump and solenoid valve are immediately shut off, and inflation is paused. The inflation speed is controlled at ≤5mm / s, and a gradual inflation method is used to avoid the pillow surface rising too quickly, which could cause the user to feel it clearly and disturb sleep.

[0131] It is particularly important to note that during airbag inflation and deflation, a delay is made to wait for the airbag pressure to stabilize before the MCU controls the pressure sensor array to collect pressure data in the shoulder and neck area again. This avoids gradient calculation deviations caused by unstable pressure, ensures the accuracy of adjustment, and achieves closed-loop regulation.

[0132] It continuously monitors the zero-gap state and dynamically adjusts the airbag pressure to respond to slight changes in posture during sleep, ensuring the continuous stability of the zero-gap state and providing continuous comfortable support for the cervical spine.

[0133] Once the zero-gap state is reached, the MCU latches the current airbag pressure value, shuts off the air pump and solenoid valve, maintains the current height of the airbag, and ensures that the pillow surface fits snugly against the neck and shoulders.

[0134] Furthermore, it continuously collects pressure gradient data in the neck and shoulder area to monitor whether the zero-gap state is stable;

[0135] If the average pressure gradient of the neck and shoulders is detected to be greater than or equal to the preset threshold and is maintained for more than 3 seconds, the PID control is restarted to perform micro-inflation adjustment until the zero-gap state is restored. If the pressure gradient remains stable, the current state is maintained. When it is determined to be a change in sleeping position, the zero-gap adjustment is stopped and the corresponding sleeping position mode is switched to avoid the problem of pressure or insufficient support caused by continuing zero-gap adjustment in a non-supine state.

[0136] If the sleeping posture is determined to be non-supine, the MCU immediately pauses the zero-gap adjustment, shuts off the air pump and solenoid valve, and switches to the corresponding adjustment mode according to the specific sleeping posture type. When the sleeping posture is determined to be stable supine again, the zero-gap adjustment process is restarted.

[0137] The pillow consists of a pillow body 1, a pillow bottom shell layer 2, and an adaptive lifting mechanism. The pillow body 1 is divided into at least two independent support areas along its length.

[0138] An MCU control unit 5 is installed on the pillow bottom shell layer 2. The MCU control unit 5 is connected to the circuit board built into the pillow bottom shell layer 2 via a data cable, and the MCU control unit 5 is externally connected to a control box 6 via a line.

[0139] Preferably, the MCU control unit 5 uses an STM32L4 series microcontroller, which supports multiple communication interfaces such as I2C, SPI, and UART. It can connect to all sensors and execution layer devices simultaneously, has sufficient computing power, supports PID algorithms and pressure gradient calculation, embeds a real-time operating system, and writes programs for sensor data acquisition, data preprocessing, pressure gradient calculation, PID control, and sleep posture fusion judgment to realize the coordinated control of various modules. The firmware can be wirelessly upgraded via Bluetooth OTA to continuously optimize the algorithm.

[0140] Furthermore, the pressure gradient calculation module integrates a pressure gradient calculation algorithm through MCU firmware programming, reads the preprocessed shoulder and neck area pressure data, calculates the average pressure gradient according to a preset formula, compares it with a preset threshold, and outputs the judgment result.

[0141] Furthermore, the PID closed-loop control module integrates the PID control algorithm in the MCU firmware, and the PID parameters can be adjusted via a local knob or Bluetooth OTA to adapt to the needs of different users.

[0142] Furthermore, the sleeping posture fusion judgment module integrates a multi-dimensional threshold judgment model, which combines data from pressure sensors, gyroscopes, and Bluetooth modules to determine whether the supine posture is valid. If all judgment conditions are met, zero-gap adjustment is triggered to avoid false triggering.

[0143] Furthermore, the parameter storage module is used to store user-customized parameters, preset thresholds, PID parameters, and adjustment logs. It is connected to the MCU control unit via I2C and supports reading, writing, and modifying parameters. Users can modify parameters through the control box 6.

[0144] A miniature air pump and a miniature solenoid valve are installed on the bottom shell layer 2 of the pillow, and a sound insulation chamber is provided on the bottom shell layer 2 of the pillow to isolate the working noise and vibration transmission of the miniature air pump and the miniature solenoid valve.

[0145] The miniature silent air pump is connected to the MCU control unit via a GPIO interface to receive inflation / stop commands from the MCU.

[0146] The miniature solenoid valve assembly is connected to the MCU control unit via a GPIO interface. The MCU controls the opening and closing of the solenoid valves to achieve synchronous or independent inflation of the left and right airbags.

[0147] The miniature solenoid valves correspond to the inflation, deflation, and pressure-holding locking paths of the independent airbag 3, respectively, and are used to achieve precise flow control and power-off pressure-holding locking during the inflation and deflation process of the independent airbag 3.

[0148] Furthermore, the power management module includes a lithium battery, a wireless charging receiver coil, a charging management chip, and a voltage regulator to provide stable power to all modules.

[0149] Two independent airbags 3 are arranged along the length of the pillow body 1 and are correspondingly set on the pillow bottom shell layer 2. A miniature air pump set on the pillow bottom shell layer 2 is connected to the independent airbags 3 through an air tube.

[0150] The independent airbag 3 is made of medical-grade thermoplastic polyurethane film, and each independent airbag 3 integrates a miniature air pressure sensor. The sensor is led out through FPC flexible cable to provide real-time feedback on the internal pressure of the airbag, forming a closed-loop control. The sampling frequency of the miniature air pressure sensor is 10Hz, and it communicates with the MCU control unit 5 through the I2C bus.

[0151] Preferably, the air pressure sensor is a miniature MEMS air pressure sensor, which is connected to the MCU control unit 5 via an SPI bus to transmit air pressure data of the airbag in real time for monitoring the inflation process and providing closed-loop feedback.

[0152] A 6-axis gyroscope is installed at the central slot 12. Preferably, a MEMS 6-axis inertial measurement unit is used, with a sampling frequency of 10Hz, an angular velocity measurement range of ±250rad / s, and an accuracy of ±0.01rad / s. It collects three-dimensional angular velocity and acceleration data of the head for the judgment of rolling events and the auxiliary judgment of supine posture, avoiding false triggering of zero-gap adjustment.

[0153] When the miniature air pressure sensor detects that the internal air pressure of the corresponding independent airbag 3 exceeds the preset safety threshold, it immediately controls the corresponding solenoid valve to perform a pressure relief action and cuts off the power supply to the corresponding air pump. When the device is powered off, the solenoid valve automatically locks the air tube to maintain the current air pressure and support height of the airbag, and sets the single continuous inflation time to not exceed 15 seconds to prevent the air pump from overheating and blocking.

[0154] The miniature solenoid valve is configured to have at least three operating states:

[0155] Inflation pathway status: The air inlet and working port are connected, and the miniature air pump delivers gas to the independent airbag 3;

[0156] Venting passage status: The working port and the exhaust port are connected to release the gas in the independent airbag 3 to the atmosphere;

[0157] Pressure holding and locking passage status: Cut off the connection between the air inlet and the working port, and cut off the connection between the working port and the exhaust port to lock the pressure in the independent airbag 3.

[0158] The central auxiliary support airbag 4 is located between the pillow body 1 and the pillow bottom shell layer 2. The central auxiliary support airbag 4 is located between the left independent support airbag 3 and the right independent support airbag 3.

[0159] The bottom of the central auxiliary support airbag 4 is connected to a miniature air pump and a miniature solenoid valve. The central auxiliary support airbag 4 is used to support the physiological curvature of the cervical spine in the supine position.

[0160] A central groove 12 is provided at the center of the pillow body 1. A flexible pressure sensor array is provided at the central groove 12 to collect pressure distribution images of the user's head and neck. The flexible pressure sensor array is an 8×8 matrix flexible printed circuit, which is used to identify the contour feature points of the head and neck to help determine the sleeping posture.

[0161] Preferably, the flexible pressure sensor array uses an FSR flexible thin-film pressure sensor with a 1024-point array and a sampling frequency of 10Hz. It is laid in the central groove 12, close to the upper surface of the pillow body 1, focusing on covering the corresponding area of ​​the shoulders and neck. The sensor spacing is 0.5cm to ensure the continuity of pressure data acquisition. It is connected to the MCU control unit 5 via an I2C bus to transmit pre-processed pressure data. The wires are wrapped in memory foam to avoid user perception.

[0162] The pillow body 1 has an independent groove 11 corresponding to the independent airbag 3 in the support area, and the independent airbag 3 is located inside the independent groove 11.

[0163] The pillow body 1 has an embedded Bluetooth communication module, preferably a low-power Bluetooth 5.2 module that supports the BLE protocol. It can passively read the orientation data of a mobile phone screen. As long as the mobile phone's Bluetooth is turned on and it can be discovered, it can help determine the supine posture by collecting the orientation data of the mobile phone screen, thereby improving the accuracy of sleeping posture recognition.

[0164] The MCU control unit 5 analyzes the data from the flexible pressure sensor array and calculates the pressure center of gravity offset. When the center of gravity is shifted to the left and the pressure in the left area is more than 30% greater than the pressure in the right area, it is determined to be a left lateral decubitus position; when the center of gravity is shifted to the right and the pressure in the right area is more than 30% greater than the pressure in the left area, it is determined to be a right lateral decubitus position; when the pressure is evenly distributed in the central area, it is determined to be a supine position.

[0165] The control box 6 is equipped with physical buttons, including a power button, a mode switch button, and a manual fine-tuning button.

[0166] The circuit board is configured to receive physical button commands from the external control box 6 transmitted via a data cable, and in response to the commands, switch operating modes or manually adjust the height of the corresponding independent airbag 3.

[0167] Furthermore, the circuit board is electrically connected to the flexible pressure sensor array, the miniature air pump, and the miniature solenoid valve. The system is powered by an external DC12V / 2A power adapter and has integrated overcurrent, overvoltage, and short-circuit protection circuits to ensure safe use.

[0168] The main control chip can be an STM32F103C8T6, which integrates an I2C interface to connect to the air pressure sensor, an ADC module to acquire pressure sensor signals, PWM output to control the air pump speed, and GPIO to drive the solenoid valve.

[0169] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A zero-gap pillow height adjustment method for pressure gradient closed-loop control, characterized in that, Includes the following steps: S1: Initialization and status monitoring, completes system hardware self-test and enters standby state, and monitors the pressure data of the user's head and neck acting on the pillow surface in real time; S2: Multi-source sleeping posture determination, collecting at least two types of sensor data including head and neck pressure distribution, head spatial posture and status of associated electronic devices to determine the current sleeping posture; S3: Pattern matching and execution. Based on the determined sleeping posture, the corresponding airbag adjustment strategy is matched. The adjustment strategy includes at least the supine zero-gap mode, the side-sleeping anti-pressure mode, and the forward-tilting support mode. S4: Pressure gradient closed-loop control. During the adjustment process, the pressure gradient value of the shoulder and neck support area is calculated in real time. The inflation and deflation volume and rate of the airbag are dynamically adjusted through the closed-loop control algorithm until the pressure gradient value converges to the preset comfort threshold range, so as to achieve dynamic zero-gap fit between the pillow surface and the shoulder and neck area.

2. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 1, characterized in that, Based on the system hardware self-test in step S1, it includes: Impedance-capacitance combined detection is performed on a flexible pressure sensor array to determine the circuit continuity and short circuit status. The air passage unobstructedness and air tightness of the airbag inflation / deflation actuator are tested. The air tightness test is achieved by inflating the airbag to the preset pressure, letting it stand, and monitoring the pressure drop.

3. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 1, characterized in that, The multi-source sleep posture determination in step S2 specifically includes: First data collection: The three-axis accelerometer and gyroscope collect pitch angle, roll angle and angular velocity data of the head's spatial attitude; Second data acquisition: A flexible pressure sensor array acquires pressure values ​​and two-dimensional spatial location information; Third data acquisition: The wireless communication module acquires the screen orientation and relative position change trends of the associated electronic devices; When at least two types of data meet the preset sleeping posture characteristics and continue for more than the set time, the sleeping posture status is confirmed to be valid.

4. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 1, characterized in that, Based on step S2, the sleeping posture includes supine position, side sleeping anti-pressure position, and side sleeping position for looking at mobile phone. The supine position must meet the following conditions simultaneously: the center of pressure is located in the center of the pillow surface, there is no rolling over event, and the screen of the associated electronic device is in portrait mode or off. The criteria for determining a side-sleeping anti-pressure posture are: the center of pressure is off-center from the pillow surface and the proportion of pressure on one side exceeds the threshold, and there is a rolling over event. To determine whether someone is looking at their phone while lying on their side, the following conditions must be met: the center of gravity is located on one side with a forward tilt, and the screen of the connected electronic device is in landscape mode.

5. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 4, characterized in that, The sleeping posture fusion determination process involves inputting the first, second, and third data into the local decision unit, using a rule-based multi-source information fusion algorithm to determine the sleeping posture, and outputting the current user's sleeping posture status.

6. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 4, characterized in that, When the sleeping position is determined to be supine, the supine zero-gap mode is triggered to perform zero-gap adjustment. If any of the first, second and third data is not met, the state is determined to be non-supine, the zero-gap adjustment is paused, and the corresponding sleeping position mode is switched. When the sleeping position is determined to be side sleeping, the corresponding side sleeping anti-pressure mode is triggered to reduce pressure. If the phone is switched to landscape mode, it is determined to be a side sleeping position for looking at the phone, the current adjustment is paused and the corresponding mode is switched. When the user is identified as sleeping on their side while looking at their phone, the corresponding "Sleeping on the side while looking at your phone" mode is triggered to perform frontal compensation adjustments. The phone is switched to portrait mode or turned off, the current adjustment is paused, and the user is switched to the "Sleeping on the side to prevent pressure" mode.

7. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 1, characterized in that, Based on step S4, calculating the pressure gradient value of the shoulder and neck support area specifically includes: The collected pressure data is denoised and normalized. Divide the area corresponding to the shoulder and neck, calculate the ratio of the pressure difference between any two adjacent pressure sampling points in the area to the distance between the two points, and take the average value of the gradients of all adjacent points as the real-time average pressure gradient value.

8. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 6, characterized in that, The patient is identified as being in a supine position and the supine zero-gap mode is triggered, specifically including: The system identifies low-pressure gaps in the area corresponding to the cervical spine, calculates the required filling height, and drives at least one set of airbags in the central axis area of ​​the pillow to inflate and lift until the pressure sensor feedback shows that the pressure in that area has reached a preset threshold.

9. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 6, characterized in that, This is determined to be a side-sleeping anti-pressure mode, specifically including: The system retrieves the user's physiological parameters and real-time tilt angle, calculates the required elevation height of the spine using a biomechanical compensation model, performs micro-deflation of the pressure side airbag and gradient micro-inflation of the support side airbag, and performs asymmetrical inflation to form an asymmetrical transition slope from the head to the shoulder.

10. The zero-gap pillow height adjustment method for pressure gradient closed-loop control according to claim 8, characterized in that, Once the adjustment reaches the zero-gap state: Lock in the current airbag pressure and collect pressure gradient data in the shoulder and neck area; If the average pressure gradient in the neck and shoulder exceeds the threshold and remains there for a set time, restart the PID control for micro-inflation adjustment. When a change in sleeping position is detected, the current adjustment is paused and the corresponding mode is switched.

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