Intelligent door lock touch screen waterproof and mistaken touch prevention control method

Abstract

The application relates to a smart door lock touch screen waterproof and mistaken touch control method, which comprises the following steps: acquiring a holding state signal collected by a plurality of sensing units arranged on a door lock handle; calibrating a predicted contact area of a user's hand relative to a touch screen based on the holding state signal; collecting a capacitance change signal generated by each touch channel of the touch screen; when the spatial coordinates of the capacitance change signal fall into the predicted contact area, the current capacitance change signal is discriminated as an active effective touch signal or a holding, rubbing and mistaken touch signal by combining the correlation between the holding state signal and the time sequence change characteristics of the capacitance change signal; and if the discrimination is a holding, rubbing and mistaken touch, a corresponding touch screen key event is inhibited. The application effectively distinguishes active input from rubbing and mistaken touch in a wet state environment, significantly reduces the mistaken touch rate, does not increase additional hardware, and meets the power consumption and structure constraints of the smart door lock.

Description

Technical Field

[0001] This application relates to the field of smart door lock control, and in particular to a waterproof and accidental touch control method for a smart door lock touchscreen. Background Technology

[0002] Smart door locks typically feature capacitive touchscreens or touch-sensitive button areas for users to input passwords, access cards, or perform other functions. Existing touchscreen anti-accidental touch solutions primarily rely on threshold judgments based on changes in the capacitance of the touch chip itself. These solutions suppress environmental interference such as rain and water films by setting sensitivity thresholds or employing filtering algorithms. Some solutions also reduce false triggering by adding infrared proximity sensors, waterproof coatings, or protective structures. These methods focus on identifying water interference or the proximity of objects on the touchscreen surface, filtering or shielding based on the characteristics of individual touch signals.

[0003] However, the touchscreen and handle of a smart lock are structurally very close together. When a user holds the handle to open the door, their palm, wrist, or fingers easily come into contact with the touchscreen surface, especially in rainy weather or with wet hands. The rubbing signal is highly similar to the actual finger tap signal in amplitude and waveform, making it difficult to effectively distinguish between active operation and unintentional rubbing based solely on the touchscreen's capacitance changes. Furthermore, when the hand hovers near the touchscreen without actually touching it, the coupling between the human body's electric field and the water film on the panel creates large-area common-mode interference, generating false touch signals without real contact. Existing solutions also lack effective means to identify and eliminate this interference. These problems lead to an increased false touch rate in wet environments, not only reducing the user experience but also potentially consuming incorrect password attempts due to accidental password input, and even causing temporary locking of the lock.

[0004] Therefore, this application proposes a waterproof and accidental touch control method for smart door lock touchscreens. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a waterproof and accidental touch-protection control method for a smart door lock touchscreen, employing the following technical solution:

[0006] A method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches includes the following steps:

[0007] Acquire grip status signals collected by multiple sensor units installed on the door lock handle;

[0008] Based on the grip state signal, the predicted contact area of ​​the user's hand relative to the smart lock touchscreen is calibrated;

[0009] Collect capacitance change signals generated by each touch channel of the touch screen;

[0010] When a capacitance change signal is detected on the touch screen, it is determined whether the spatial coordinates of the capacitance change signal fall into the predicted contact area.

[0011] If the spatial coordinates of the capacitance change signal fall into the predicted contact area, then by combining the correlation between the temporal change characteristics of the grip state signal and the temporal change characteristics of the capacitance change signal, the current capacitance change signal is identified as an active and effective touch signal or a grip rubbing touch / accidental touch signal.

[0012] If the touch is identified as a hand rubbing or accidental touch during the gripping of the handle, the touch screen button event corresponding to the capacitance change signal will be suppressed.

[0013] Preferably, the plurality of sensing units are a plurality of capacitive sensing electrodes evenly arranged along the circumference of the door lock handle, and each capacitive sensing electrode independently collects and outputs the capacitance change; the grip state signal is formed by integrating the capacitance changes output by all the capacitive sensing electrodes.

[0014] Preferably, the step of determining the predicted contact area of ​​the user's hand relative to the smart lock touchscreen based on the grip state signal includes:

[0015] Based on the capacitance change of each capacitive sensing electrode, the area covered by the user's hand on the door lock handle and the distribution position of the hand in the handle area are calculated.

[0016] By combining the coverage area, hand distribution position, and fixed physical relative position of the door lock handle and the touch screen, a dynamic spatial mask that adapts to the current grip posture is dynamically generated.

[0017] The coverage area of ​​the dynamic spatial mask on the touchscreen is determined as the predicted contact area of ​​the user's hand.

[0018] Preferably, the step of combining the temporal variation characteristics of the grip state signal and the temporal variation characteristics of the capacitance change signal to identify whether the current capacitance change signal is an active and valid touch signal or a grip-induced accidental touch signal includes:

[0019] If, within the first time window before the rising edge of the capacitance change signal, the grip state signal exhibits a falling edge or slight jitter, and a shift in the user's hand position is detected, it is determined to be a valid operation where the user actively taps the touchscreen after removing their hand from the handle, and signal suppression is not performed; the first time window is a preset time period before the rising edge of the capacitance change signal.

[0020] If the grip state signal remains stable and the fluctuation amplitude is less than the preset fluctuation threshold during the complete duration of the capacitance change signal, it is determined to be a haphazard touch by the user's hand while gripping the handle, and signal suppression is performed.

[0021] Preferably, the suppression processing of the touch screen button event corresponding to the capacitance change signal includes performing at least one of the following operations:

[0022] Discard the touch screen button event corresponding to the current capacitance change signal directly.

[0023] Temporarily reduce the touch sensitivity of the touch channel on the touchscreen where the current capacitance change signal is located;

[0024] The current key press event is marked as a low-confidence invalid event, and is not counted in the cumulative count of incorrect entry lock passwords.

[0025] Preferably, it also includes enhanced anti-accidental touch measures in the case of door closing vibration:

[0026] Real-time acquisition of door lock closing status signals to identify the moment when the door lock closing action is completed;

[0027] Within a preset short time window after the door closing action is completed, if the grip status signal detects that the user's hand has not left the door lock handle and is still in a gripping state, an enhanced suppression strategy is executed on the capacitance change signal collected by the touch screen to filter out the accidental touch signals caused by water droplet slippage and splashing due to the door closing vibration.

[0028] When the preset time window ends or the timing characteristics of user-initiated touch are detected, the enhancement suppression strategy is lifted and the normal touch screen recognition logic is restored.

[0029] Preferably, it also includes a wet suspension common-mode interference elimination step:

[0030] Based on the capacitance change gradient of multiple sensing units, the spatial state of the user's hand is calculated, and the hovering and approaching state of the hand and the corresponding hovering orientation are identified.

[0031] If it is determined that the user's hand is in a suspended and close state, and the global base capacitance drift of the touch screen is greater than the preset drift threshold, then it is determined that there is a common mode interference field formed by the human body suspended and coupled water film on the touch screen surface.

[0032] By combining the hand's hovering orientation with the real-time updated predicted contact area, a hovering interference spread mask with a range larger than the predicted contact area is generated;

[0033] Common-mode differential cancellation processing is performed on the capacitance change signal falling within the floating interference spread area mask;

[0034] If the remaining capacitance signal after differential elimination does not meet the preset finger touch timing characteristics, then the corresponding pseudo touch event is filtered out.

[0035] Preferably, the step of calculating the spatial state of the user's hand based on the capacitance change gradient of multiple sensing units, and identifying the hand's hovering proximity state and corresponding hovering orientation, includes:

[0036] Differential operation is performed on the capacitance signals collected by each sensing unit to generate a capacitance gradient vector characterizing the change in hand distance;

[0037] When the magnitude of the capacitance gradient vector is greater than the preset hovering recognition threshold and less than the physical contact threshold, it is determined that the user's hand is in a hovering and approaching state.

[0038] Based on the direction of the capacitance gradient vector, the hovering position of the user's hand relative to the touchscreen is determined.

[0039] Preferably, the common-mode differential cancellation processing of the capacitance change signal falling within the floating interference spread area mask includes:

[0040] The capacitance changes of all touch channels within the floating interference spread mask are statistically analyzed, and the average value is calculated as the common-mode interference component of the current region.

[0041] Subtract the common-mode interference component from the original capacitance change signal of each touch channel to obtain the differential touch signal after removing the water film common-mode interference.

[0042] Preferably, the preset finger touch timing features include:

[0043] The signal rising edge duration is less than the preset rising edge time threshold.

[0044] The amplitude fluctuation during the steady-state phase of the signal is less than the preset fluctuation threshold;

[0045] The duration of the falling edge of the signal is less than the preset falling edge time threshold.

[0046] Furthermore, the effective signal is concentrated only within a single touch channel or the range of two adjacent touch channels.

[0047] In summary, this application includes at least one of the following beneficial technical effects:

[0048] 1. This application dynamically calibrates the predicted contact area of ​​the user's hand relative to the touch screen by integrating the spatial position and temporal correlation characteristics of the multi-point grip state signal on the door lock handle and the capacitance change signal of the touch screen. It can pre-lock the range of buttons that may be accidentally touched in the spatial dimension, and perform time-series discrimination on the capacitance change signal falling into this range. This effectively distinguishes between the user's active password input and accidental touches caused by the hand gripping the handle. It significantly reduces the accidental touch rate in wet environments, while not inhibiting the user's normal password input, thus improving the usability of smart door locks in complex scenarios such as rainy days and wet hands.

[0049] 2. This application enhances the anti-accidental touch steps in the door closing vibration scenario. Within a preset short time window after the door closing action is completed, it enhances and suppresses the touch screen capacitance change signal, filters out the accidental touch signal caused by water droplet sliding and splashing caused by door closing vibration, solves the problem that the touch screen is easily triggered by mechanical vibration and water droplet superposition interference in a short period of time after the user closes the door, and further improves the reliability of anti-accidental touch.

[0050] 3. This application eliminates common-mode interference in wet conditions by using the capacitance change gradient of multiple capacitive sensing electrodes to identify the hovering proximity and hovering orientation of the user's hand. It also determines the common-mode interference field formed by the human body's suspension coupled with the water film by combining the global substrate capacitance drift of the touchscreen. Furthermore, it filters out false touch events by using a suspension interference spread mask and common-mode differential elimination processing. This solves the problem that existing solutions cannot identify large-area false capacitive touch signals generated by the coupling of the human body's electric field with the water film when the hand is not in contact with the touchscreen but is hovering nearby. This further reduces the risk of accidental touches in high-humidity environments.

[0051] 4. This application excludes low-confidence invalid key events generated by suppression processing from the cumulative password error count, thereby preventing rainwater, water film, or floating false touches from causing the door lock to be temporarily locked by a large number of invalid password inputs in a short period of time, preventing secondary risks to security logic caused by accidental touches, and ensuring the normal unlocking ability of legitimate users in wet environments.

[0052] 5. This application does not require additional hardware sensors. It fully utilizes the existing multi-point sensing unit on the door lock handle and the capacitance detection capability of the touch screen itself. Waterproof and accidental touch prevention control is achieved through software algorithms. It does not increase material costs or hardware failure rate. It meets the design constraints of battery power supply, compact structure and integrated appearance of smart door locks, and has good engineering feasibility and versatility. Attached Figure Description

[0053] Figure 1 This is a flowchart of a method for controlling the waterproof and accidental touch prevention of a smart door lock touchscreen, as described in an embodiment of this application. Detailed Implementation

[0054] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0055] This application proposes a waterproof and accidental touch control method for smart door lock touchscreens, used to distinguish between user-initiated password input and accidental touch signals generated by hand rubbing against the touchscreen while gripping the handle in wet environments. The core concept of this method is to no longer use touchscreen capacitance change signals as the sole criterion, but instead simultaneously introduce multi-point grip state signals from the door lock handle. Utilizing the spatial position information of the user's hand reflected in the grip posture, the method predicts the area where the hand might rub against the touchscreen. Then, combining the spatial position of the touchscreen capacitance change signals and the temporal correlation between the two, the method identifies the touchscreen capacitance change signals and ultimately decides whether to suppress the corresponding key event. This method is applicable to smart door locks with capacitive touch password areas. The smart door lock includes a lock body, a handle, and a touchscreen. The handle and touchscreen are physically adjacent, typically with a spacing of 2 to 10 centimeters. A processor is installed inside the lock to execute the various steps of this method.

[0056] Reference Figure 1 A method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches includes the following steps:

[0057] S1. Acquisition of grip status signal: Acquire grip status signal collected by multiple sensor units set on the door lock handle;

[0058] S2. Calibration of predicted contact area: Based on the grip state signal, calibrate the predicted contact area of ​​the user's hand relative to the smart door lock touch screen;

[0059] S3. Acquisition of touch screen capacitance change signals: Acquire capacitance change signals generated by each touch channel of the touch screen;

[0060] S4. Matching and judging the spatial position of capacitance change signal: When a capacitance change signal is detected on the touch screen, it is judged whether the spatial coordinates of the capacitance change signal fall into the predicted contact area.

[0061] S5. Timing correlation identification between active touch and grip touch: If it falls into the category, the correlation between the timing change characteristics of the grip state signal and the timing change characteristics of the capacitance change signal will be combined to identify whether the current capacitance change signal is an active and effective touch signal or a grip touch accidental touch signal.

[0062] S6. Suppression of accidental button touch events: If the accidental touch is identified as a hand rubbing during the gripping of the handle, the touch screen button event corresponding to the capacitance change signal is suppressed. In addition, this application also provides enhanced anti-accidental touch steps in the door closing vibration scenario, as well as wet suspension common-mode interference elimination steps, as supplements and extensions to the above core anti-accidental touch process.

[0063] To acquire grip status signals, the door lock handle is equipped with multiple sensing units to detect the user's hand contact and proximity to the handle in real time. In this embodiment, the sensing units are capacitive sensing electrodes, which are evenly distributed along the circumference of the handle. Specifically, 6 to 12 capacitive sensing electrodes, preferably 8, are arranged inside or on the surface of the handle's grip area. Each capacitive sensing electrode is arc-shaped and attached to the inner wall of the handle or embedded in the inner side of the handle's outer shell, with the electrodes spaced apart and electrically insulated from each other. Each capacitive sensing electrode independently acquires and outputs the capacitance change reflecting the capacitive coupling strength between itself and the human body. The processor performs baseline tracking and differential processing on the raw capacitance value of each electrode to obtain the capacitance change. Taking eight electrodes numbered 1 to 8 as an example, the gripping state signal can be represented as an 8-dimensional vector G, G=[ΔC1,ΔC2,ΔC3,ΔC4,ΔC5,ΔC6,ΔC7,ΔC8], where ΔCi is the capacitance change of the i-th capacitive sensing electrode, which is equal to the difference between the real-time capacitance value at the current sampling moment and the preset baseline capacitance value. The baseline is determined using a moving average or long-term slow tracking method, continuously updated under conditions of no human contact to eliminate the influence of temperature drift and slow environmental changes. Furthermore, when the processor detects a significant change in ambient humidity or continuous water film interference, for example, when the capacitance changes of multiple capacitive sensing electrodes simultaneously exceed the preset water film threshold within a preset time, and the change pattern exhibits large-area, slow drift characteristics, baseline updates are paused or the baseline update rate is reduced to avoid learning the capacitance offset caused by the water film as the baseline. Once the water film interference is detected to be eliminated, for example, when the capacitance change recovers to near the original baseline and the fluctuation amplitude is less than the preset threshold, baseline updates are resumed, or the baseline value stored before the water film interference occurred is reverted. This baseline management strategy also applies to baseline processing for each touch channel of the touchscreen.

[0064] It should be noted that the sensing unit is not limited to capacitive sensing electrodes. In alternative embodiments, the sensing unit may also be a thin-film pressure sensor or strain gauge, attached to the inner wall or outer surface of the handle. The pressure sensor outputs an electrical signal proportional to the gripping pressure, and the processor normalizes each pressure signal to form a gripping state signal. Regardless of the sensing principle used, the above-mentioned gripping state acquisition, predicted contact area calibration, timing correlation judgment, and suppression processing logic remain consistent. However, the suspension common-mode interference cancellation step based on capacitance change gradient is only applicable to embodiments where the sensing unit is a capacitive sensing electrode; for alternative embodiments using a pressure sensor, suspension common-mode interference cancellation can be achieved by additionally setting an infrared proximity sensor or an ambient light sensor, or this step can be omitted.

[0065] After obtaining the grip state vector G, the processor determines the predicted contact area of ​​the user's hand relative to the touchscreen based on G. The purpose of this step is to calculate which parts of the hand may come into contact with which areas of the touchscreen due to swinging, displacement or posture adjustment during the action, given that the user's grip posture is known.

[0066] Specifically, the processor compares each element in the grip state vector G with a preset contact determination threshold. When the capacitance change ΔCi of a certain electrode exceeds the contact determination threshold, it is determined that the electrode position is effectively covered by the user's hand. The number of electrodes exceeding the threshold is counted, and combined with the known electrode coverage area, the area covered by the hand on the handle is estimated. The contact determination threshold is pre-calibrated according to the electrode material and installation method; in this embodiment, it is set to 30% of the full-scale capacitance change.

[0067] Simultaneously, based on the electrode numbers exceeding the contact detection threshold and their angular positions in the handle's circumferential direction, the angular coordinates of the hand's center of gravity in the circumferential direction are calculated. For example, when electrodes numbered 2, 3, 4, and 5 out of the eight electrodes exceed the threshold, the hand's center of gravity is located in the angular region between electrodes 3 and 4, indicating that the hand is mainly distributed on the side of the handle closer to the touchscreen. The processor maps this angular coordinate to lateral position information relative to the touchscreen.

[0068] The processor then combines the coverage area, hand distribution position, and pre-stored fixed physical relative position parameters of the door lock handle and the touch screen to generate a dynamic spatial mask. This mask is represented in the form of a set of touch screen button coordinates, and the coverage area of ​​the dynamic spatial mask is the predicted contact area of ​​the user's hand.

[0069] For example, when the hand's center of gravity is located on the side of the handle closer to the touchscreen and the coverage area exceeds a preset area threshold, the dynamic spatial mask covers all the touch channels of a row of buttons on the touchscreen adjacent to the handle; when the coverage area is small and only the fingertips cover the handle surface, the mask shrinks to cover only the single button or two adjacent buttons corresponding to the fingertip position; when the hand's center of gravity is far from the touchscreen side, the mask is an empty set, that is, no subsequent spatial suppression is performed.

[0070] The dynamic spatial mask updates in real time as the grip state signal changes. When the user adjusts their grip posture, the mask coverage area adjusts synchronously to ensure that the predicted contact area always matches the current hand posture.

[0071] The touchscreen comprises multiple touch channels, each corresponding to a physical button or sensing area. Taking a 12-key keypad as an example, each button corresponds to an independent touch channel, and each touch channel has pre-calibrated spatial coordinates. The processor periodically scans all touch channels, acquires the capacitance changes of each channel, and records the spatial coordinates of the capacitance change signals.

[0072] When the capacitance change of a certain touch channel exceeds the touch trigger threshold of the touch screen itself, it is determined that a capacitance change signal has been generated in that channel. The processor extracts the channel coordinates of the signal, matches them with the current dynamic spatial mask, and determines whether the spatial coordinates of the signal fall within the predicted contact area.

[0073] If the spatial coordinates of the capacitance change signal do not fall within the predicted contact area, it indicates that the signal comes from a direct click by the user's finger on an unpredictable area. This signal is not subject to timing correlation judgment and is directly processed as a normal touch event without suppression.

[0074] If the spatial coordinates of the signal fall within the predicted contact area, it indicates that the signal may be caused by the user's hand rubbing against the touchscreen while holding the handle, and the timing correlation judgment is initiated.

[0075] For capacitance change signals that fall into the predicted contact area, the processor further distinguishes them by combining the correlation between the timing change characteristics of the grip state signal and the timing change characteristics of the capacitance change signal.

[0076] The processor extracts the timing features of the capacitance change signal, including the rising edge time, rising edge duration, peak amplitude, steady-state duration, and falling edge duration. Simultaneously, it extracts the timing features of the grip state signal before and after the capacitance change signal occurs, including the amplitude trends of the capacitance changes at each electrode and the positional changes of the grip vector's centroid.

[0077] If, within the first time window before the rising edge of the capacitance change signal, the grip state signal exhibits a falling edge or slight jitter, and a shift in the user's hand position is detected, it is determined that the user's hand has detached from the handle or is in the process of detaching from the handle and is actively reaching towards the touchscreen to click. This is considered a valid operation, and signal suppression is not performed. The capacitance change signal is directly treated as a normal button event.

[0078] In this embodiment, the first time window is set to 0 to 200 milliseconds before the rising edge of the capacitance change signal; the falling edge of the amplitude refers to the decrease in the capacitance change of the electrodes closest to the touchscreen in the grip state vector exceeding 15% of the full scale within the first time window; the hand position offset change refers to the offset of the angular coordinate of the center of gravity of the grip vector exceeding a preset offset threshold, such as 15 degrees, within the first time window. If the grip state signal remains stable throughout the complete duration of the capacitance change signal, and the fluctuation amplitude of the capacitance change of each electrode is less than the preset fluctuation threshold, it is determined that the user's hand accidentally touched the touchscreen while maintaining the grip posture while holding the handle, which is considered a mis-touch, and signal suppression is performed at this time.

[0079] In this embodiment, the preset fluctuation threshold is set to 10% of the full-scale capacitance change. The complete duration refers to the entire time between the rising edge and the falling edge of the capacitance change signal. The fluctuation amplitude refers to the difference between the maximum and minimum values ​​of each element in the holding state vector during this period.

[0080] Through the above timing correlation judgment, the processor can further distinguish between two action modes, namely "release first and then click" and "hold and rub while touching", based on the timing relationship, provided that the spatial position falls within the prediction area. This avoids misidentifying the user's unintentional touch while holding the handle as password input, and also avoids suppressing the user's active release and click error.

[0081] When the processor determines that the current capacitance change signal is an accidental touch due to gripping or rubbing, it performs suppression processing on the corresponding touchscreen button event. The suppression processing may include at least one of the following three methods; this embodiment employs both the first and third methods.

[0082] The first suppression method is to directly discard the touch screen button event corresponding to the current capacitance change signal. The processor intercepts the button event before it enters the door lock password input logic, so that the event does not participate in the password sequence combination and does not trigger button sound or vibration feedback.

[0083] The second suppression method is to temporarily reduce the touch sensitivity of the touch channel where the current capacitance change signal is located. The processor multiplies the touch trigger threshold of the touch channel by a sensitivity adjustment coefficient greater than 1, such as 1.5 to 3 times, so that subsequent capacitance change signals of the same amplitude will no longer meet the trigger condition. This reduced sensitivity state lasts for a preset time, such as 2 seconds, and then automatically recovers, or recovers in advance when the processor detects that the grip state signal indicates that the user's hand has completely left the handle.

[0084] The third suppression method is to mark the current key event as a low-confidence invalid event. This event can still be reported by the touch chip, but it does not participate in the password sequence comparison in the door lock's password input verification logic, and it is not counted in the cumulative count of incorrect door lock passwords. This method is especially suitable for scenarios where the door lock may exhaust the number of incorrect passwords and enter temporary lock due to a large number of invalid key presses, thus avoiding the situation where a legitimate user is locked out due to accidental touches.

[0085] Shortly after a user closes the door, the door lock's mechanical structure vibrates. This vibration may cause water droplets adhering to the touchscreen surface to slide, splash, or redistribute, generating capacitance changes on the touchscreen. Simultaneously, users often retain their hand on the handle after closing the door, and the hand contact combined with water droplet interference may cause additional issues. Therefore, this application provides a door-closing vibration enhancement and suppression step based on the core anti-accidental touch process.

[0086] The processor acquires the door lock's closing status signal in real time. This signal can be provided by a door magnetic sensor, a latch position switch, or a motor current detection signal. The processor performs edge detection on the closing status signal to identify the moment the door lock's closing action is completed. Specifically, when the door magnetic sensor output changes from the open state to the closed state, this change moment is recorded as the closing action completion moment. Within a preset short time window after the closing action completion moment, the processor monitors the grip status signal. In this embodiment, the preset short time window is set to 0.5 to 3 seconds, preferably 1.5 seconds. If, within this time window, the grip status signal indicates that the user's hand has not removed from the door lock handle and is still in a gripping state—for example, if the capacitance change of any electrode in the grip status vector still exceeds the contact determination threshold—the processor executes an enhancement and suppression strategy on the capacitance change signal acquired by the touchscreen.

[0087] The enhanced suppression strategy is as follows: for capacitance change signals generated on the touchscreen within the time window, regardless of whether their spatial position falls within the predicted contact area, the corresponding button event is directly discarded, or its recognition sensitivity is reduced to more than three times the normal level. When the preset time window ends, or the processor detects the timing characteristics of user active touch, such as a capacitance change signal with a fast rising edge and a grip state signal showing release characteristics, the enhanced suppression strategy is deactivated, and the normal touchscreen recognition logic is restored.

[0088] In high-humidity environments, a user's hand may not be in direct contact with the touchscreen, but rather hovering close to it. In this situation, the human body's electric field couples with the water film on the touchscreen surface, simultaneously generating capacitance changes of similar amplitude and synchronized waveforms across multiple touch channels, forming a common-mode interference field. The spatial distribution range of this common-mode interference signal is typically larger than the predicted contact area of ​​a physical touch, and its individual signal characteristics differ from those of a real finger touch. However, it is difficult to effectively distinguish between them based solely on the touchscreen's amplitude threshold.

[0089] To address this issue, this application inserts a floating common-mode interference cancellation step after acquiring the touchscreen capacitance change signal and before timing correlation determination. This step is applicable to embodiments where the sensing unit is a capacitive sensing electrode.

[0090] The processor performs differential operations on the capacitance signals collected by each capacitive sensing electrode. Taking an arrangement of eight electrodes as an example, the difference in capacitance changes between adjacent electrodes is calculated as gᵢ=ΔCᵢ₊1-ΔCᵢ. All differential values ​​are then used to form a capacitance gradient vector. When the user's hand is away from the handle, the capacitance changes of each electrode are small, and the magnitude of the gradient vector is close to zero. When the hand touches the handle, the capacitance changes of some electrodes increase significantly, and the magnitude of the gradient vector reaches above the physical contact threshold. When the hand hovers near the handle but does not touch it, the capacitance changes of the electrodes closer to the hand increase significantly, while the changes of the electrodes farther away are smaller, and the magnitude of the gradient vector is between the two.

[0091] In this embodiment, the magnitude of the capacitance gradient vector is calculated using the Euclidean norm. When the magnitude of the gradient vector is greater than a preset hovering recognition threshold and less than a physical contact threshold, it is determined that the user's hand is in a hovering and approaching state. Both thresholds are obtained through pre-calibration. Simultaneously, based on the direction of the gradient vector, the orientation of the hand's center of gravity relative to the handle is determined, and then mapped to the hovering orientation of the hand relative to the touchscreen.

[0092] The suspension distance is obtained by converting the magnitude of the capacitance gradient vector with a pre-calibrated distance-gradient relationship curve. The calibration method for the distance-gradient relationship curve is as follows: Before leaving the factory, in a standard environment, a simulated hand or metal block at a known distance is brought close to the handle, and the magnitude of the capacitance gradient vector at each distance setting is recorded. A distance-gradient magnitude correspondence table is established, and the distance-gradient relationship curve is obtained using piecewise linear interpolation or polynomial fitting, and stored in the door lock processor. As an example, in an 8-electrode scheme, a gradient vector magnitude of 0.5 corresponds to a distance of 30 mm, 1.0 corresponds to 20 mm, 1.8 corresponds to 10 mm, 3.0 corresponds to 5 mm, and 5.0 and above correspond to a contact state. The gradient magnitude increases approximately exponentially as the distance decreases, and can be fitted using an exponential function: d = a·exp(-b·|grad|), where exp represents the exponential operation with the natural constant e as the base, |grad| is the magnitude of the capacitance gradient vector, and a and b are calibration coefficients. The specific values ​​of a and b can be determined as follows: Substitute at least three sets of distance and gradient magnitude data from the aforementioned distance-gradient magnitude correspondence table into the exponential function, and solve using least squares fitting or linear regression methods. This fitting process is completed during the calibration phase before the door lock leaves the factory. The fitted values ​​of a and b are stored in the door lock processor for real-time calculation of the floating distance during actual use.

[0093] The processor detects the global base capacitance drift of the entire touchscreen, defined as the arithmetic mean of the capacitance changes across all touch channels. When this average exceeds a preset drift threshold, it indicates the presence of a large area of ​​water film or condensation on the touchscreen surface, and that this water film has caused an overall capacitance shift in the touchscreen channels. The preset drift threshold can be set to 3 to 5 times the average base capacitance fluctuation under normal dry conditions. When both the hand hovering and the global base capacitance drift exceeding the threshold are met simultaneously, it is determined that a common-mode interference field formed by a human body suspending and coupling with the water film exists on the touchscreen surface.

[0094] Subsequently, based on the generated dynamic spatial mask, the processor expands the mask range according to the hovering orientation and hovering distance. The expansion rules are as follows: when the hovering distance is no more than 5 mm, the mask is expanded outward by the width of one button; when the hovering distance is between 5 mm and 15 mm, it is expanded by the width of two buttons; when the hovering distance is greater than 15 mm, it is expanded by the width of three buttons. The area obtained after expansion is the hovering interference expansion mask.

[0095] The capacitance change signal falling within the floating interference spread area mask is processed by common-mode differential cancellation. The processor counts the capacitance change of all touch channels within the floating interference spread area mask, calculates the arithmetic mean, and uses this mean as the common-mode interference component of the current area. Then, the original capacitance change signal of each touch channel within the mask is subtracted from the common-mode interference component to obtain the differential touch signal after removing the water film common-mode interference.

[0096] It should be noted that if a certain channel in the mask has been initially identified as a candidate for real finger touch, for example, if its capacitance change amplitude is significantly higher than that of other channels, this channel can be excluded when calculating the common-mode component to avoid mistakenly subtracting the real finger signal.

[0097] Finger touch timing characteristics are detected on the remaining capacitance signal after differential elimination. The preset finger touch timing characteristics include: the signal rising edge duration is less than a preset rising edge time threshold, which is 80 milliseconds in this embodiment and preferably 50 milliseconds; the amplitude fluctuation during the steady-state holding phase of the signal is less than a preset fluctuation threshold, which is 10% of the full scale in this embodiment; the signal falling edge duration is less than a preset falling edge time threshold, which is 120 milliseconds in this embodiment and preferably 80 milliseconds; and the effective signal is concentrated only in a single touch channel or within the range of two adjacent touch channels.

[0098] If the remaining signal after differential elimination meets all the above characteristics, it is determined to be a real finger touch, the corresponding button event is retained and the normal recognition process is entered; if the remaining signal does not meet the above characteristics, for example, it still has a large area, multiple channels, and slow drift, it is determined to be a pseudo touch event caused by common mode interference and is filtered out.

[0099] As a preferred additional embodiment, this method can also be linked with door lock security counting logic. When the processor determines that it is currently in a water interference scenario or a floating common-mode interference scenario, key events marked as low-confidence invalid events by the suppression processing are not counted in the cumulative count of incorrect door lock passwords, thereby preventing rainwater, water film, or floating false touches from causing the door lock to be temporarily locked by a large number of invalid password inputs in a short period of time.

[0100] In a further embodiment, when the processor detects continuous and severe water interference, such as the global substrate capacitance drift of the touchscreen continuously exceeding a preset drift threshold for more than 30 seconds, and no timing characteristics of user active touch are detected, the user can be prompted to use other authentication methods such as fingerprint, Bluetooth, NFC, or mechanical key through the door lock's voice prompt module or indicator light. However, the touchscreen input function should not be simply and directly turned off to ensure the availability of the password when the user still needs to use it.

[0101] This application's method effectively distinguishes between user-initiated password input and accidental touches caused by hand contact while gripping the handle by integrating the spatial location and temporal correlation of multi-point handle grip status signals and touchscreen capacitance change signals. This addresses the pain points of high accidental touch rates and poor usability in complex scenarios such as rain, wet hands, and high humidity. Compared to existing technologies that rely solely on the touchscreen's own capacitance threshold for judgment, this method significantly reduces the probability of false triggering in wet environments while maintaining normal recognition capability for user password input with wet hands. Furthermore, it eliminates the need for additional hardware sensors, complying with the battery power consumption and structural design constraints of smart locks.

[0102] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A waterproof and accidental touch-protection control method for a smart door lock touchscreen, characterized in that, Includes the following steps: Acquire grip status signals collected by multiple sensor units installed on the door lock handle; Based on the grip state signal, the predicted contact area of ​​the user's hand relative to the smart lock touchscreen is calibrated; Collect capacitance change signals generated by each touch channel of the touch screen; When a capacitance change signal is detected on the touch screen, it is determined whether the spatial coordinates of the capacitance change signal fall into the predicted contact area. If the spatial coordinates of the capacitance change signal fall into the predicted contact area, then by combining the correlation between the temporal change characteristics of the grip state signal and the temporal change characteristics of the capacitance change signal, the current capacitance change signal is identified as an active and effective touch signal or a grip rubbing touch / accidental touch signal. If the touch is identified as a hand rubbing or accidental touch during the gripping of the handle, the touch screen button event corresponding to the capacitance change signal will be suppressed.

2. The method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches according to claim 1, characterized in that, The multiple sensing units are multiple capacitive sensing electrodes evenly arranged around the circumference of the door lock handle. Each capacitive sensing electrode independently collects and outputs the capacitance change. The grip state signal is formed by integrating the capacitance changes output by all the capacitive sensing electrodes.

3. The method for controlling a smart door lock touchscreen with waterproof and accidental touch prevention according to claim 2, characterized in that, The step of determining the predicted contact area of ​​the user's hand relative to the smart lock touchscreen based on the grip state signal includes: Based on the capacitance change of each capacitive sensing electrode, the area covered by the user's hand on the door lock handle and the distribution position of the hand in the handle area are calculated. By combining the coverage area, hand distribution position, and fixed physical relative position of the door lock handle and the touch screen, a dynamic spatial mask that adapts to the current grip posture is dynamically generated. The coverage area of ​​the dynamic spatial mask on the touchscreen is determined as the predicted contact area of ​​the user's hand.

4. The method for controlling a smart door lock touchscreen with waterproof and accidental touch prevention according to claim 1, characterized in that, The method of combining the temporal variation characteristics of the grip state signal and the temporal variation characteristics of the capacitance change signal to identify whether the current capacitance change signal is an active and valid touch signal or a grip-induced accidental touch signal includes: If, within the first time window before the rising edge of the capacitance change signal, the grip state signal exhibits a falling edge or slight jitter, and a shift in the user's hand position is detected, it is determined to be a valid operation where the user actively taps the touchscreen after removing their hand from the handle, and signal suppression is not performed; the first time window is a preset time period before the rising edge of the capacitance change signal. If the grip state signal remains stable and the fluctuation amplitude is less than the preset fluctuation threshold during the complete duration of the capacitance change signal, it is determined to be a haphazard touch by the user's hand while gripping the handle, and signal suppression is performed.

5. A method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches according to claim 1, characterized in that, The suppression processing of the touch screen button event corresponding to the capacitance change signal includes performing at least one of the following operations: Discard the touch screen button event corresponding to the current capacitance change signal directly. Temporarily reduce the touch sensitivity of the touch channel on the touchscreen where the current capacitance change signal is located; The current key press event is marked as a low-confidence invalid event, and is not counted in the cumulative count of incorrect entry lock passwords.

6. The method for controlling a smart door lock touchscreen with waterproof and accidental touch prevention according to claim 1, characterized in that, It also includes enhanced steps to prevent accidental touches during door-closing vibration scenarios: Real-time acquisition of door lock closing status signals to identify the moment when the door lock closing action is completed; Within a preset short time window after the door closing action is completed, if the grip status signal detects that the user's hand has not left the door lock handle and is still in a gripping state, an enhanced suppression strategy is executed on the capacitance change signal collected by the touch screen to filter out the accidental touch signals caused by water droplet slippage and splashing due to the door closing vibration. When the preset time window ends or the timing characteristics of user-initiated touch are detected, the enhancement suppression strategy is lifted and the normal touch screen recognition logic is restored.

7. A method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches according to claim 2, characterized in that, It also includes a wet suspension common-mode interference elimination step: Based on the capacitance change gradient of multiple sensing units, the spatial state of the user's hand is calculated, and the hovering and approaching state of the hand and the corresponding hovering orientation are identified. If it is determined that the user's hand is in a floating and close state, and the global base capacitance drift of the touch screen is greater than the preset drift threshold, then it is determined that there is a common mode interference field formed by the human body floating and coupling water film on the touch screen surface. By combining the hand's hovering orientation with the real-time updated predicted contact area, a hovering interference spread mask with a range larger than the predicted contact area is generated; Common-mode differential cancellation processing is performed on the capacitance change signal falling within the floating interference spread area mask; If the remaining capacitance signal after differential elimination does not meet the preset finger touch timing characteristics, then the corresponding pseudo touch event is filtered out.

8. A method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches according to claim 7, characterized in that, The method of calculating the spatial state of the user's hand based on the capacitance change gradient of multiple sensing units, and identifying the hand's hovering proximity state and corresponding hovering orientation includes: Differential operation is performed on the capacitance signals collected by each sensing unit to generate a capacitance gradient vector characterizing the change in hand distance; When the magnitude of the capacitance gradient vector is greater than the preset hovering recognition threshold and less than the physical contact threshold, it is determined that the user's hand is in a hovering and approaching state. Based on the direction of the capacitance gradient vector, the hovering position of the user's hand relative to the touchscreen is determined.

9. A method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches according to claim 7, characterized in that, The common-mode differential cancellation processing of the capacitance change signal falling within the floating interference spread area mask includes: The capacitance changes of all touch channels within the floating interference spread mask are statistically analyzed, and the average value is calculated as the common-mode interference component of the current region. Subtract the common-mode interference component from the original capacitance change signal of each touch channel to obtain the differential touch signal after removing the water film common-mode interference.

10. A method for controlling a smart door lock touchscreen that is waterproof and prevents accidental touches according to claim 7, characterized in that, The preset finger touch timing features include: The signal rising edge duration is less than the preset rising edge time threshold. The amplitude fluctuation during the steady-state phase of the signal is less than the preset fluctuation threshold; The duration of the falling edge of the signal is less than the preset falling edge time threshold. Furthermore, the effective signal is concentrated only within a single touch channel or the range of two adjacent touch channels.

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