Electric blanket self-adapting temperature regulation and its heating abnormality blocking protection system

Abstract

The present application relates to the technical field of intelligent household electric heating appliance and temperature control protection, in particular to an electric blanket adaptive temperature regulation and its heating abnormality blocking protection system, comprising an electric blanket body and a controller; each heating area is provided with a heating wire assembly, a temperature sensor and an alternating current power device, the heating wire assembly comprises an inner heating wire, a temperature sensing insulation layer and a safety signal wire; the controller comprises a setting unit, a detection module, a time sequence control module, an abnormality judgment module and a driving protection module; detection pulses are sent and phase delay is obtained during the shutdown period, combined with temperature information, environmental information and historical reference data for abnormality judgment, the on proportion of the alternating current power device is controlled and power reduction, local power failure, whole machine power failure, alarm and fault recording are executed, realizing temperature control and safety protection cooperation.

Description

Technical Field

[0001] This invention relates to the field of smart home electric heating appliances and temperature control and protection technology, specifically to an electric blanket with adaptive temperature regulation and a system to prevent abnormal heating. Background Technology

[0002] Electric blankets, as a common heating product, typically generate heat through heating wires and are equipped with temperature sensors, thermostats, and overheat protection devices to achieve temperature regulation and safety protection. To balance user comfort and operational safety, existing electric blankets generally control the heating power according to the set temperature and implement power reduction or power-off protection when the temperature exceeds the threshold to avoid adverse effects caused by excessively high surface temperature of the blanket.

[0003] However, in actual use of electric blankets, the heating wires may be affected by localized pressure, folding, changes in coverage thickness, and changes in ambient temperature and humidity, which may lead to localized heat accumulation and abnormal heating. If the judgment is made solely based on the temperature sensor readings or a single over-temperature threshold, there are often problems with detection lag and inaccurate identification. On the other hand, increasing the number of temperature sensors to improve detection accuracy would increase structural complexity and would still make it difficult to fully cover the localized abnormal areas.

[0004] Therefore, the existing temperature control and protection methods for electric blankets are unable to identify local heating abnormalities in time before the temperature reaches the preset over-temperature threshold, thus affecting the safety of electric blanket operation and the reliability of control. Summary of the Invention

[0005] The purpose of this invention is to provide an adaptive temperature regulation system for electric blankets and a system for blocking and protecting against abnormal heating, which avoids the problems of detection lag and inaccurate identification caused by relying solely on temperature sensors in the prior art. Moreover, it can identify and classify local abnormal heating before the temperature reaches the over-temperature threshold without adding high-density temperature sensors, thereby improving the safety of electric blanket operation and the reliability of control.

[0006] The objective of this invention can be achieved through the following technical solution: an electric blanket adaptive temperature regulation and its heating abnormality blocking protection system, comprising an electric blanket body and a controller; the electric blanket body includes at least one heating zone, each heating zone being equipped with a heating wire assembly, a temperature sensor, and an AC power device; the heating wire assembly includes an inner heating wire, a temperature-sensing insulation layer covering the outer periphery of the inner heating wire, and a safety signal wire disposed outside the temperature-sensing insulation layer; the controller is electrically connected to the temperature sensor, the AC power device, and the safety signal wire, and includes a setting unit, a detection module, a timing control module, an abnormality judgment module, and a drive protection module; the setting unit is used to receive the input set temperature of each heating zone; the detection module is used to collect zero-crossing signals, the temperature of each heating zone, and the ambient temperature. The system includes temperature, ambient humidity, set temperature, and coupling signals on the safety signal wire; a timing control module controls the AC heating and shutdown periods of each heating zone based on the zero-crossing signal, and sends a detection pulse during the shutdown period to obtain the phase delay; an anomaly judgment module performs anomaly judgment based on the phase delay, temperature of each heating zone, ambient temperature, ambient humidity, and historical reference data, and outputs temperature adjustment and protection commands; a drive protection module controls the conduction ratio of AC power devices in each heating zone according to the temperature adjustment command, and executes power reduction, time-limited heating, partial power-off, whole-machine power-off, audible and visual alarms, and fault recording according to the protection command; historical reference data includes at least the reference phase, phase fluctuation threshold, phase growth threshold, and heating rate threshold.

[0007] Preferably, the detection module includes a zero-crossing detection unit, a temperature detection unit, an environmental detection unit, and a coupling signal detection unit; the zero-crossing detection unit is used to detect the AC zero-crossing point and output a synchronization signal to the timing control module; the temperature detection unit is used to acquire the temperature values ​​of the temperature sensors in each heating zone; the environmental detection unit is used to acquire the ambient temperature and ambient humidity; the coupling signal detection unit is used to acquire the coupling signal on the safety signal wire after the timing control module sends the detection pulse, and send the coupling signal to the timing control module.

[0008] Preferably, the timing control module includes a time-division control unit, a delay waiting unit, a pulse sending unit, and a phase detection unit; the time-division control unit is used to allocate the timing of the on-time and off-time of each heating zone according to the zero-crossing signal; the delay waiting unit is used to perform a delay waiting after the AC power device of the corresponding heating zone is turned off; the pulse sending unit is used to send a detection pulse between the inner heating wire and the safety signal wire of the target heating zone within the time window after the delay waiting unit ends; the phase detection unit is used to determine the phase delay amount according to the edge timing relationship between the detection pulse and the coupling signal.

[0009] Preferably, the anomaly detection module includes a storage unit, a deviation calculation unit, a judgment unit, and a protection control unit. The storage unit stores the initial phase, reference phase, phase fluctuation threshold, phase growth threshold, heating rate threshold, over-temperature threshold, first threshold, second threshold, and a set number of continuous triggers, wherein the first threshold is less than the second threshold. The deviation calculation unit obtains parameters reflecting the phase change state based on the phase delay, and these parameters include at least the phase change amount in the current detection cycle and the phase change trend over multiple consecutive detection cycles. The judgment unit determines the anomaly judgment value based on temperature information, environmental information, and the phase change state parameters. The protection control unit records the number of continuous triggers and compares... The system uses anomaly detection values, a first threshold, a second threshold, and a combination of continuous trigger counts for tiered protection: When the anomaly detection value is less than the first threshold, a normal state flag is output and the current conduction ratio is maintained; when the anomaly detection value reaches the first threshold but is less than the second threshold, a warning state flag is output, along with a local power reduction command and a shortened detection cycle command; when the anomaly detection value reaches the second threshold and the continuous trigger count has not reached the set continuous trigger count, the warning state flag is maintained and the continuous trigger count is accumulated; when the heating zone temperature reaches the over-temperature threshold and the phase change parameter in the phase change state reaches the phase fluctuation threshold and / or the phase change trend reaches the phase growth threshold, a severe fault state flag is output, along with a whole-machine power-off command.

[0010] Preferably, the drive protection module includes a power control unit, an alarm unit, and a fault recording unit; the power control unit is used to receive temperature adjustment commands and protection commands output by the abnormality judgment module, and to control the conduction, shutdown, and conduction ratio of the AC power devices in each heating zone; the alarm unit is used to issue an audible and visual alarm when there is a partial power failure or a power failure of the whole machine; the fault recording unit is used to record the heating zone where the abnormality occurred, the fault level, the power failure time, and the lockout status.

[0011] Preferably, the anomaly determination value is determined based on the phase change state parameter and the heating parameter, combined with the phase fluctuation threshold, phase growth threshold, heating rate threshold and preset weights; wherein, the heating parameter is a parameter characterizing the temperature change rate within multiple consecutive detection cycles; the anomaly determination value is determined by the determination unit based on the phase change amount of the current detection cycle, the phase change trend of multiple consecutive detection cycles and the comprehensive characteristic evaluation of the heating parameter.

[0012] Preferably, when the anomaly determination value of a certain heating zone is less than the first threshold, the reference phase of that heating zone is updated.

[0013] Preferably, each heating zone is equipped with at least one temperature sensor, which is located on the blanket surface of the corresponding heating zone; the safety signal wire extends along the inner heating wire and wraps around the outside of the temperature-sensing insulation layer; the anomaly judgment module obtains the conduction ratio of each heating zone from the drive protection module and reads the reference phase from the historical reference data from the storage unit; the judgment unit corrects the parameters of the phase change state and the heating parameters based on the ambient temperature, ambient humidity, conduction ratio of each heating zone and reference phase.

[0014] Preferably, the AC power devices are integrated and packaged inside the controller, or distributed in each heating zone of the electric blanket body and communicate with the controller.

[0015] Preferably, the deviation calculation unit is used to perform a moving average processing on the phase change amount within multiple consecutive detection cycles, and send the obtained phase change state parameters to the determination unit.

[0016] The beneficial effects of this invention are:

[0017] 1) The electric blanket body of the present invention is equipped with heating wire components, temperature sensors and AC power devices in each heating zone. During the off period of the AC power devices, the controller sends a detection pulse between the inner heating wire and the safety signal wire, and determines the phase delay based on the coupling response. Combined with temperature information, environmental information and historical reference data, anomaly judgment is made, and then the conduction ratio of the AC power devices is controlled accordingly and partial power-off or whole-machine power-off protection is executed. This scheme can form a detection circuit using the original safety signal wire and heating wire. Without adding high-density temperature sensors, it can identify early abnormal heating caused by local pressure, folding, etc., in advance. It has the advantages of reducing detection lag, reducing false judgments and improving the temperature control safety and operational reliability of the electric blanket. Attached Figure Description

[0018] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0019] Figure 1 This is a structural block diagram of an electric blanket adaptive temperature regulation and its abnormal heating blocking protection system provided in an embodiment of the present invention. Detailed Implementation

[0020] 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.

[0021] Please see Figure 1 An electric blanket adaptive temperature regulation and heating abnormality prevention system includes an electric blanket body and a controller. The electric blanket body includes at least one heating zone, each heating zone having a heating wire assembly, a temperature sensor, and an AC power device. The heating wire assembly includes an inner heating wire, a temperature-sensing insulation layer covering the outer periphery of the inner heating wire, and a safety signal wire disposed outside the temperature-sensing insulation layer. The controller is electrically connected to the temperature sensor, AC power device, and safety signal wire, and includes a setting unit, a detection module, a timing control module, an abnormality judgment module, and a drive protection module. The setting unit is used to receive the input set temperature for each heating zone. The module is used to collect zero-crossing signals, temperatures of each heating zone, ambient temperature, ambient humidity, set temperature, and coupling signals on the safety signal wire; the timing control module is used to control the AC heating and shutdown periods of each heating zone based on the zero-crossing signals, and sends a detection pulse during the shutdown period to obtain the phase delay; the anomaly judgment module is used to judge anomalies based on the phase delay, temperatures of each heating zone, ambient temperature, ambient humidity, and historical reference data, and outputs temperature adjustment and protection commands; the drive protection module is used to control the conduction ratio of AC power devices in each heating zone according to the temperature adjustment command, and execute power reduction, time-limited heating, etc., according to the protection command. Partial power failure, overall power failure, audible and visual alarms, and fault recording; historical reference data includes at least the reference phase, phase fluctuation threshold, phase growth threshold, and heating rate threshold; the detection module includes a zero-crossing detection unit, a temperature detection unit, an environmental detection unit, and a coupling signal detection unit; the zero-crossing detection unit detects the AC zero-crossing point and outputs a synchronization signal to the timing control module; the temperature detection unit acquires the temperature values ​​of the temperature sensors in each heating zone; the environmental detection unit acquires the ambient temperature and humidity; the coupling signal detection unit collects the coupling signal on the safety signal wire after the timing control module sends a detection pulse. The coupling signal is then sent to the timing control module. The timing control module includes a time-division control unit, a delay waiting unit, a pulse sending unit, and a phase detection unit. The time-division control unit is used to allocate the conduction half-cycle and turn-off half-cycle of each heating zone according to the zero-crossing signal. The delay waiting unit is used to perform a delay waiting after the AC power device in the corresponding heating zone is turned off. The pulse sending unit is used to send a detection pulse between the inner heating wire and the safety signal wire of the target heating zone within the time window after the delay waiting unit ends. The phase detection unit is used to determine the phase delay based on the edge timing relationship between the detection pulse and the coupling signal.

[0022] The connections between the components are as follows: the setting unit is connected to the detection module and the anomaly judgment module, sending the set temperature of each heating zone to the detection module and the anomaly judgment module; the zero-crossing detection unit in the detection module is connected to the time-division control unit in the timing control module, outputting a synchronization signal to the time-division control unit; the temperature detection unit and the environmental detection unit are respectively connected to the anomaly judgment module, sending the temperature of each heating zone, the ambient temperature, and the ambient humidity to the anomaly judgment module; the input end of the coupling signal detection unit is connected to the safety signal wire, and the output end is connected to the phase detection unit in the timing control module, sending the collected coupling signal to the phase detection unit; the pulse sending unit in the timing control module is connected to the target... The inner heating wire and safety signal wire of the marked heating zone are connected. The phase detection unit is connected to the deviation calculation unit in the anomaly judgment module, and outputs the phase delay to the deviation calculation unit. The anomaly judgment module is bidirectionally connected to the drive protection module. The anomaly judgment module obtains the conduction ratio of each heating zone from the drive protection module and outputs temperature adjustment command and protection command to the drive protection module. The power control unit in the drive protection module is connected to the AC power device of each heating zone, and controls the conduction, shutdown and conduction ratio of the AC power device. The AC power device is connected in series in the AC power supply circuit of the heating wire assembly of the corresponding heating zone. The temperature sensor is arranged at the carpet position of the corresponding heating zone and connected to the temperature detection unit.

[0023] This embodiment uses a dual-temperature zone electric blanket as an example, but the control method is also applicable to three or more heating zones; the electric blanket body is divided into multiple heating zones, and each heating zone is equipped with a set of heating wire components, a temperature sensor and a corresponding AC power device.

[0024] The inner heating wire in the heating wire assembly is responsible for AC heating. The temperature-sensing insulation layer is located on the outer periphery of the inner heating wire. It is used to maintain insulation and reflect the dielectric changes after being heated and compressed. The safety signal wire is wound on the outside of the temperature-sensing insulation layer. It retains the function of a safety trigger conductor and is also used as a detection electrode during normal operation.

[0025] The controller is implemented using a microcontroller or a control chip with the same function; the setting unit receives the set temperature input for each heating zone and writes the set temperature of each heating zone into the internal storage area of ​​the controller.

[0026] The controller records the set temperature of each heating zone as the target temperature of that zone; the detection module is connected to various sensors and safety signal wires to continuously collect the temperature of each heating zone, ambient temperature, ambient humidity, zero-crossing signal, and coupling signal on the safety signal wire.

[0027] In this embodiment, the phase delay refers to the time difference between the transmission edge of the detection pulse and the coupling response edge on the safety signal wire.

[0028] The controller determines the phase delay based on edge timing relationships. Since the coupling amplitude is affected by process variations, contact conditions, and external interference, and the phase delay has a preset sensitivity to changes in insulation thickness and dielectric constant; the phase difference... Based on the detection pulse frequency and phase delay They jointly decide that the following equation applies to all three parties: ;in, Pi; the timing control module obtains the phase delay. Then, it is converted into a phase difference according to the above formula. The current phase value of the current detection cycle of the heating zone is output and stored to unify the data processing dimensions of the anomaly judgment module.

[0029] The descriptions of phase change, reference phase, and related judgment operations for each heating zone in the following text are all based on the converted phase value by default; the detection pulse frequency is selected in a preset frequency band that does not overlap with the mains frequency and its low-order harmonics, so that the change in the distributed capacitance of the heating wire assembly can be reflected in the phase change.

[0030] In use, the preset frequency range is 10kHz to 900kHz to balance detection sensitivity and circuit implementation difficulty. Within one control cycle, the time-division control unit first determines whether each heating zone is currently in the on or off half-cycle based on the synchronization signal provided by the zero-crossing detection unit. If a heating zone is assigned to the on state in this half-cycle, the corresponding AC power device is turned on, and the inner heating wire receives AC power for heating. If the heating zone is assigned to the off state in this half-cycle, the corresponding AC power device remains off, reserving a window for subsequent detection. Since the heating current and the detection signal share the same heating wire structure, the AC heating period and the off period are separated in time to avoid interference from AC high voltage on the coupled signal. Within the off window, the delay waiting unit first executes a preset waiting process. The trigger condition for this waiting process is that the AC power device of the corresponding heating zone has been turned off.

[0031] The purpose of the delay is to allow residual ringing and transient interference in the line to attenuate before entering the detection window; the waiting length is greater than the attenuation time constant of the residual interference in the line, and the waiting time is less than the preset shutdown time window length; after the waiting period ends, the pulse sending unit sends a low-voltage detection pulse between the inner heating wire and the safety signal wire of the target heating area; this detection pulse is preferably a high-frequency square wave or a narrow pulse train, and its amplitude is set to be less than or equal to 5V and greater than the level range of the offset voltage of the front-end operational amplifier.

[0032] When a detection pulse is applied to the inner heating wire, a response signal is coupled out onto the safety signal wire; the coupling signal detection unit limits the amplitude of this response signal to the peak voltage. Within the range, it is fed into a high-frequency hardware comparator and compared with a preset reference voltage threshold. The system compares the values ​​and captures the moment when the amplitude first positively crosses the threshold. This value is then converted into a digital level and sent to the phase detection unit in the timing control module via a high-speed digital isolation device.

[0033] The phase detection unit uses the transmission edge of the detection pulse as the starting reference and the rising edge of the digital level output by the digital isolation device as the ending reference, calculates the time difference between the two, and obtains the phase delay of the current detection cycle. For each heating zone, the controller completes the detection independently according to the above process. Therefore, the temperature of multiple temperature zones can be controlled separately, and abnormalities can be identified separately.

[0034] In this embodiment, the ambient temperature, ambient humidity, and temperature of each zone collected by the detection module are not used in isolation, but together with the phase delay amount, they constitute the input for subsequent anomaly judgment. Since changes in ambient humidity, bedding coverage, and pressure state will cause deviations in the electrical characteristics of the heating wire component, the controller stores historical reference data, including at least the reference phase, phase fluctuation threshold, phase growth threshold, and heating rate threshold.

[0035] The reference phase is derived from the average value of multiple measurements during the power-on self-test phase and the low-risk operation phase, and is used as the reference phase for the heating zone; the phase fluctuation threshold is used to measure whether the phase change in a single instance or short window exceeds the normal fluctuation range; the phase growth threshold is used to measure whether the phase change continues to increase over multiple detection cycles; the heating rate threshold is used to constrain the rate of temperature change and avoid misjudgment caused by relying solely on electrical signals.

[0036] The drive protection module controls the conduction ratio of AC power devices in each heating zone according to the temperature adjustment command output by the anomaly judgment module. The conduction ratio refers to the proportion of half-cycles during which AC power devices are allowed to conduct within a preset control cycle, which reflects the power output of the heating zone.

[0037] If the temperature of a heating zone is lower than the set temperature and there is no abnormality, the drive protection module increases the conduction ratio of that zone; if the temperature of that zone is close to the set temperature but the phase delay increases abnormally, the conduction ratio is reduced first.

[0038] If a significant abnormality occurs in the area, a partial power outage will be performed; if the abnormality has reached the protection conditions of the entire machine, a power outage will be performed on all heating areas, triggering audible and visual alarms and fault recording; for example, under long-term pressure on one side of the heating area, the temperature-sensing insulation layer is locally thinned, the equivalent distance between the inner heating wire and the safety signal wire decreases, and the distributed capacitance increases.

[0039] Correspondingly, the timing of the propagation and coupling response of the detection pulse in the heating zone is offset, and the phase delay obtained by the controller will deviate from the historical reference.

[0040] At this time, even if the surface temperature of the heating zone does not reach the preset temperature threshold, the anomaly judgment module will issue a temperature adjustment command based on the change in phase delay, so as to reduce the conduction ratio of the zone by the drive protection module, thereby reducing the heat accumulation caused by continued heating.

[0041] The technical advantages of the above structure and operation are as follows: by using the existing safety signal wire and heating wire to form a detection circuit, without adding a high-density temperature sensor, local heating anomalies can be identified early by extracting the detection pulse and phase delay within the shutdown window. At the same time, the identification results are directly applied to the conduction ratio and protection action of the AC power device, so that temperature control and safety protection are completed in the same control cycle.

[0042] In a preferred embodiment of the present invention, the anomaly judgment module includes a storage unit, a deviation calculation unit, a judgment unit, and a protection control unit; the storage unit is used to store the initial phase, the reference phase, the phase fluctuation threshold, the phase growth threshold, the heating rate threshold, the over-temperature threshold, the first threshold, the second threshold, and the number of continuous triggering settings, wherein the first threshold is less than the second threshold.

[0043] The deviation calculation unit is used to obtain parameters reflecting the phase change state based on the phase delay. The parameters of the phase change state include at least the phase change amount in the current detection cycle and the phase change trend in multiple consecutive detection cycles.

[0044] The judgment unit is used to determine the abnormal judgment value based on parameters such as temperature information, environmental information, and phase change status.

[0045] The protection control unit is used to record the number of continuous triggers, compare the abnormal judgment value with the first threshold and the second threshold, and perform graded protection based on the number of continuous triggers: when the abnormal judgment value is less than the first threshold, it outputs a normal state flag and maintains the current conduction ratio.

[0046] When the anomaly detection value reaches the first threshold but is less than the second threshold, an early warning status flag is output, along with a local power reduction command and a shortened detection cycle command.

[0047] When the abnormal judgment value reaches the second threshold and the number of continuous triggers does not reach the set number of continuous triggers, the warning status mark is maintained and the number of continuous triggers is accumulated; when the heating zone temperature reaches the over-temperature threshold and the phase change amount in the phase change status parameter reaches the phase fluctuation threshold and / or the phase change trend reaches the phase growth threshold, a serious fault status mark is output and a whole machine power-off command is output.

[0048] The drive protection module includes a power control unit, an alarm unit, and a fault recording unit. The power control unit is used to receive temperature adjustment commands and protection commands output by the anomaly judgment module, and to control the conduction, shutdown, and conduction ratio of the AC power devices in each heating zone.

[0049] The alarm unit is used to issue an audible and visual alarm when there is a partial or complete power failure; the fault recording unit is used to record the abnormal heating zone, fault level, power failure time, and lockout status.

[0050] The anomaly determination value is based on the phase change state parameters and the heating parameters, and is determined by combining the phase fluctuation threshold, phase growth threshold, heating rate threshold and preset weights; among them, the heating parameters are parameters that characterize the rate of temperature change within multiple consecutive detection cycles.

[0051] The anomaly determination value is determined by the determination unit based on the phase change amount of the current detection cycle, the phase change trend of multiple consecutive detection cycles, and the comprehensive characteristic evaluation of the heating parameters; when the anomaly determination value of a certain heating zone is less than the first threshold, the reference phase of the heating zone is updated.

[0052] The anomaly detection module is located inside the controller and includes a storage unit, a deviation calculation unit, a judgment unit, and a protection control unit. Each unit is executed by the processor in the controller according to a preset program and data is read and written through the internal memory. In this embodiment, the initial phase refers to the average value of the reference phase collected by the system in the initial self-test stage or the early stage of low-power operation, which is used to establish the initial reference state of each heating zone.

[0053] The reference phase refers to the reference phase that is allowed to be iteratively updated according to a preset cycle under subsequent abnormal conditions, and is used to reflect the normal state after long-term material aging and seasonal changes; the phase change amount refers to the difference between the phase delay amount of the current detection cycle and the previous detection cycle or the reference phase; the phase change trend refers to the direction and degree of increase of the phase change amount within multiple consecutive detection cycles.

[0054] The heating parameter refers to the ratio of the temperature change to the corresponding cycle length in two or more consecutive detection cycles, which is used to reflect the heating rate of the heating zone. After receiving the phase delay of the current detection cycle, the deviation calculation unit first calculates the phase change of the current detection cycle. In order to reduce the impact of single sampling fluctuations on the judgment result, this embodiment preferably uses multiple consecutive detection cycles to form a sliding window.

[0055] Within this sliding window, the deviation calculation unit sequentially reads the phase change amount of each cycle, calculates the average change level of these phase changes, and thus obtains the phase change trend. When transient fluctuations occur, the overall deviation within the sliding window does not exceed a preset threshold. When there is a continuously developing local anomaly, the phase change amount within the continuous detection cycle accumulates in a single direction. The calculation rules construct a mapping relationship between multi-cycle data sequences and a single feature parameter.

[0056] The determination unit simultaneously receives temperature information, environmental information, and phase change state parameters output by the deviation calculation unit; the temperature information comes from the temperature sensors of each heating zone, and the environmental information comes from the ambient temperature and ambient humidity sensors; the determination unit calculates the abnormal determination value according to the following logic structure: the ratio of the phase change amount of the current detection cycle to the phase fluctuation threshold of the heating zone is obtained as the first item.

[0057] The ratio of the phase increase to the phase increase threshold obtained from the phase change trend in multiple consecutive detection cycles is used as the second term; the ratio of the heating parameter to the heating rate threshold is used as the third term.

[0058] To avoid the negative output caused by transient cooling or negative phase shift from canceling out the real local positive accumulation anomaly, the decision unit performs non-negative constraint processing when acquiring the first, second, and third items. That is, when any calculated ratio is less than zero, it is forcibly truncated to zero.

[0059] The first, second, and third items are multiplied by their respective preset weights and then summed. The sum of the preset weights of each item is one. The resulting weighted sum is the abnormality judgment value of the heating zone.

[0060] Specifically, the preset weights are set based on the differences in sensitivity of each parameter to early anomalies. Under normal bedding conditions, electrical anomalies such as local pressure often occur before the temperature rises significantly. Therefore, the sum of the weights of the first and second items is set to be greater than the weight of the third item.

[0061] For example, the preset weight value range for the first item can be set to 0.3 to 0.4, the preset weight value range for the second item can be set to 0.4 to 0.5, and the preset weight value range for the third item can be set to 0.15 to 0.25. The sum of the three is strictly 1, so as to ensure sensitivity to electrical characteristics while taking temperature safety into account.

[0062] Based on the combined calculation of phase change state parameters and heating parameters, abnormal states can be identified from the dual dimensions of electrical and thermal signals. Sometimes phase abnormalities appear first, and sometimes heating rate abnormalities appear first. Combining the two makes it easier to distinguish early abnormalities from normal operating conditions.

[0063] The data calculation rule for the heating parameter is as follows: extract the temperature value of the heating zone in the current detection cycle, subtract the temperature value of the previous preset number of detection cycles, and obtain the temperature change.

[0064] Divide the temperature change by the total length of the corresponding detection cycle to calculate the temperature rise parameters of the heating zone.

[0065] The number of cycles is set to an integer greater than or equal to two to adapt to different power outputs and operating conditions; the first threshold and the second threshold are stored in the storage unit, and the first threshold is less than the second threshold; the first threshold is used for early warning judgment, and the second threshold is used for fault judgment.

[0066] Preferably, the threshold is determined based on the statistical results of normal operating conditions obtained from baseline learning, that is, under no abnormal conditions, the abnormal judgment value is collected for N consecutive detection cycles and its mathematical expectation is calculated. and standard deviation The first threshold is calculated using the mean and volatility levels as references: Second threshold: ;in, The first threshold, The second threshold, As the first safety multiplier factor, It is the second safety multiplier factor; and The preset value range is 1.5 to 3.0, and .

[0067] The dynamic threshold calculation method is used to accommodate basic characteristic deviations introduced by differences in material batches, environmental humidity, and regional structure. After obtaining the abnormal judgment value, the protection control unit first compares it with the first threshold and the second threshold, and then combines it with the number of continuous triggers to perform graded protection. The number of continuous triggers refers to the number of times the abnormal judgment value reaches the preset level within the most recent consecutive preset number of detection cycles, which is used to avoid direct power outage caused by transient disturbances such as short-term overturning and sudden changes in humidity.

[0068] The processing procedure is as follows: When the current abnormal judgment value of a certain heating zone is less than the first threshold, the protection control unit outputs a normal status flag and maintains the current conduction ratio unchanged; when the abnormal judgment value reaches the first threshold and is less than the second threshold, the protection control unit outputs a warning status flag and sends a local power reduction command to the drive protection module, and sends a shortening detection cycle command to the timing control module, so that the heating zone enters the detection more frequently in subsequent operation.

[0069] When the abnormal judgment value reaches the second threshold, and the state is continuously triggered a set number of times in continuous judgment, the protection control unit outputs a fault status mark and issues a partial power-off command to stop the corresponding heating zone from heating. To ensure the rigor of the graded protection logic, the partial power-off command here is specifically manifested as the drive protection module completely cutting off the AC power device drive signal corresponding to the abnormal heating zone, and this shutdown state is directly locked by the system until the whole machine is powered on and reset, thus forming a final safety blocking control closed loop to deal with continuous local thermal anomalies.

[0070] When the temperature of the heating zone reaches the over-temperature threshold, and the phase change reaches the phase fluctuation threshold and / or the phase change trend reaches the phase growth threshold, the protection control unit outputs a serious fault status flag and issues a power-off command for the entire unit. If only the ambient humidity change rate is lower than the preset change rate threshold or the bedding coverage changes, the phase change will be expressed as an offset rate lower than the preset offset rate threshold, and will not maintain a high-risk value for multiple consecutive judgment cycles. If the heating wire is continuously subjected to local pressure, changes in the insulation layer thickness and dielectric properties will cause the phase change to accumulate continuously, thus increasing the number of consecutive triggers. By adopting this condition, the probability of false power-off can be reduced.

[0071] After receiving temperature adjustment and protection commands, the power control unit in the drive protection module directly controls the on / off state and on / off ratio of the AC power devices in each heating zone. For example, in the warning state, the power control unit lowers the on / off ratio of the target heating zone according to a preset power reduction coefficient. This preset power reduction coefficient can be a preset fixed value stored in the storage unit, or it can be dynamically matched and calculated by the power control unit based on the difference between the abnormal judgment value and the first threshold. The larger the difference, the larger the corresponding reduction. This achieves smooth and adaptive power reduction adjustment.

[0072] Specifically, the dynamic matching calculation follows a defined quantization mapping rule: the difference between the current anomaly determination value and the first threshold is calculated, and this difference is divided by a preset threshold range, i.e., the difference between the second threshold and the first threshold, to obtain the anomaly degree ratio; this anomaly degree ratio is multiplied by a preset maximum allowable power reduction ratio, such as 50%, and the resulting product is the preset power reduction coefficient used for the current power reduction adjustment. The quantization mapping rule determines the calculation basis for adaptive power reduction adjustment; other heating zones can continue to work according to their respective states.

[0073] As a collaborative defense mechanism for adaptive power reduction adjustment, the system also specifically sets time-limited heating protection logic. When the target heating zone is in a warning state and is running with reduced power, the drive protection module will simultaneously activate the safety timing function. If the continuous working time of the heating zone in this power reduction state reaches the preset maximum safe duration threshold, the drive protection module will forcibly cut off the conduction path of the AC power device in the heating zone to avoid the risk of local heat accumulation that may still be caused by long-term low-power heat input.

[0074] In a fault state, the target heating zone is cut off, while other heating zones can maintain limited operation; in a severe fault state, all heating zones are de-energized; the alarm unit outputs audible and visual prompts when there is a partial or complete power failure, and the fault recording unit records the abnormal heating zone, fault level, power failure time, and lockout status for subsequent maintenance or manual reset; this embodiment also stipulates that when the abnormal judgment value of a certain heating zone is less than the first threshold, the reference phase of that heating zone is updated; the update is performed by a slow adjustment method, rather than directly replacing the original reference phase with the current phase.

[0075] The data flow logic of its update rule is as follows: extract the reference phase before the update and multiply it by a preset forgetting factor to obtain the historical reference component; at the same time, extract the phase value measured in the current detection cycle and multiply it by the difference between 1 and the forgetting factor to obtain the current state component; add the historical reference component and the current state component together, and use this sum as the reference phase of the heating zone after the update in the current detection cycle.

[0076] The forgetting factor is preferably set between 0.95 and 0.99. This range ensures that the system can filter out transient interferences that occur in a single instance or within a short period of time, and can gradually absorb long-term material aging and slow environmental changes over dozens of detection cycles. Updates are only allowed when the anomaly judgment value is below the first threshold, which can prevent abnormal states from being mistakenly absorbed into the baseline.

[0077] When used for long-term bed rest, if a heating zone is slightly folded due to local turning and dragging, the phase change will increase first, and the phase growth in the sliding window will also gradually increase. If at the same time the heating parameter of the zone reaches the preset heating rate threshold, the abnormal judgment value calculated by the judgment unit will quickly approach or exceed the first threshold, and the system will first enter the warning and reduce power.

[0078] If the anomaly persists, the number of consecutive triggers will accumulate to a set value, and the system will execute a partial power-off. If the temperature in that area continues to reach the over-temperature threshold and the phase change is still significant, the system will upgrade to a full power-off. It can output a partial power reduction command for early anomalies and also cut off the power supply when the anomaly judgment value reaches the full power-off threshold.

[0079] The anomaly detection does not rely on a single temperature over-limit condition, but uses the phase change amount, phase change trend and heating parameters together for judgment, and suppresses occasional fluctuations by continuously triggering the number of times, so that local heating anomalies can be identified and graded before the temperature is obviously too high; in a preferred embodiment of the present invention, each heating zone is provided with at least one temperature sensor, and the temperature sensor is arranged at the blanket surface position of the corresponding heating zone; the safety signal wire extends along the inner heating wire and wraps around the outside of the temperature sensing insulation layer.

[0080] The anomaly detection module obtains the conduction ratio of each heating zone from the drive protection module and reads the reference phase from the historical reference data from the storage unit; the judgment unit corrects the phase change state parameters and temperature rise parameters based on the ambient temperature, ambient humidity, conduction ratio of each heating zone, and reference phase; the AC power devices are integrated and packaged inside the controller, or distributed in each heating zone of the electric blanket body and communicate with the controller; the deviation calculation unit is used to perform a moving average processing on the phase change amount in multiple consecutive detection cycles and sends the obtained phase change state parameters to the judgment unit.

[0081] At least one temperature sensor is placed on the blanket surface in each heating zone. The temperature sensors are positioned on the blanket surface to collect temperatures for temperature control and heating parameter calculations. A safety signal wire extends along the inner heating wire and wraps around the outside of the temperature-sensing insulation layer, creating a distributed coupling relationship between the two along the entire length of the heating wire. This structure ensures that changes in insulation layer thickness caused by localized pressure, bending, or heat accumulation will be reflected in the corresponding section's coupling characteristics. The controller includes a zero-crossing detection unit, a timing control module, an anomaly detection module, and a drive protection module. The heating wire components and temperature sensors for each heating zone are located within the electric blanket itself. The controller is connected to AC power devices, an environmental detection unit, and... The temperature sensor and safety signal wire are electrically connected; the zero-crossing detection unit obtains a synchronization reference from the mains power side, and the timing control module arranges the heating and detection windows accordingly; the temperature sensor sends the blanket surface temperature of each heating zone to the controller; the environmental detection unit sends the ambient temperature and humidity to the controller; the safety signal wire sends the coupling response signal to the detection front end; the drive protection module outputs on and off control to the AC power device; in this way, the controller can obtain objective physical quantity input and can also directly convert the abnormal judgment result into control action of the AC power device; during operation, the ambient temperature, ambient humidity, and the conduction ratio of each heating zone will jointly affect the phase detection result and the temperature rise.

[0082] For example, increased ambient humidity may cause a slow change in the electrical properties of the insulation layer surface; an increased conduction ratio will cause the overall temperature of the heating zone to rise faster; when the ambient temperature decreases, the heating rate will be different under the same conduction ratio; to prevent normal operating condition differences from being judged as abnormal, the abnormal judgment module reads the conduction ratio of each heating zone from the drive protection module in each judgment cycle, and reads the current reference phase of that zone from the storage unit. Then, combined with the ambient temperature and ambient humidity, it corrects the phase change state parameters and heating parameters before entering the judgment unit; correction refers to establishing a mapping relationship between the detected value and the current operating conditions; Specifically, the following quantitative adjustment coefficient can be used for correction: When the difference between the ambient humidity measured by the environmental detection unit and the humidity increase in the previous reference time period exceeds the preset humidity change threshold, such as 10% relative humidity, the judgment unit multiplies the phase fluctuation threshold used in the first calculation by a humidity tolerance coefficient greater than 1. The value of this humidity tolerance coefficient ranges from 1.2 to 1.5, thereby increasing the tolerance for single phase fluctuations. At the same time, the second preset weight is increased and the first preset weight is reduced by an equal amount, such as adjusting the difference to 0.1, so as to rely more on the phase change trend in multiple consecutive detection cycles.

[0083] The reference time period is a time window consisting of multiple consecutive detection cycles before the current detection cycle. When the current conduction ratio of the heating zone drops below the preset low load ratio threshold while the heating parameter is still greater than zero, the judgment unit increases the preset weight of the third item, i.e., the ratio item corresponding to the heating parameter, by a preset compensation amount, such as 0.1 to 0.2, and proportionally compresses the weights of other items. The low load ratio threshold is 30% of the total control cycle for half a conduction cycle.

[0084] During this compression process, the determination unit has a built-in minimum weight lower limit. If the weight of a certain item after compression is lower than this lower limit, the lower limit value is forcibly maintained. After all weights are adjusted, a forced normalization operation is performed. The specific normalization formula is as follows: ;in, For the weight of the i-th term after forced normalization, The weight of the i-th term after adjustment before forced normalization, The weight of the j-th term after adjustment before forced normalization; the values ​​of i and j are 1, 2, and 3, respectively, corresponding to the weights of the first, second, and third terms in the calculation of the anomaly determination value.

[0085] The weights are redistributed using the above formula to ensure that the dynamically adjusted feature monitoring sensitivity is not masked and to strictly maintain the dimensional consistency required for mathematical expectation calculation, thereby quantifying and increasing the influence weight of the heating parameter in the anomaly judgment value; when the difference between the reference phase and the initial phase exceeds the preset allowable range, the current reference phase is used to replace the initial phase as the comparison benchmark; the correction logic is used to filter out detection deviations caused by changes in normal operating conditions.

[0086] The deviation calculation unit performs a moving average process on the phase change over multiple consecutive detection cycles. The processing order is as follows: first, read the current phase delay and calculate the current phase change in each detection cycle; then, form a sliding window with the phase changes from the most recent multiple consecutive detection cycles; average the values ​​in the window to obtain the smoothed phase change state parameter; and then send the parameter to the judgment unit.

[0087] The specific moving average calculation logic is as follows: A moving window is formed by extracting the most recent N consecutive detection cycles, including the current detection cycle; all phase changes within this moving window are summed and divided by the number of detection cycles N contained within the moving window to obtain the moving average phase change of the heating zone within the current window; the window length can be selected within a preset range to balance response speed and disturbance rejection capability; the moving average window length is positively correlated with disturbance rejection and negatively correlated with abnormal response rate; the moving average processing is used to reduce the calculation weight of transient disturbances and accumulate persistent parameter offset characteristics.

[0088] In an environment with humidity compensation, the environmental detection unit detects a continuous increase in ambient humidity, but the conduction ratio of a certain heating zone does not change significantly, and the temperature rise parameter of the blanket surface remains within the normal range. At this time, although the original phase change may have a certain deviation, the judgment unit will correct the phase change according to the current humidity conditions after reading the ambient humidity and the reference phase, and will give priority to referring to the phase change trend after the moving average. If the trend does not continue to increase, the abnormal judgment value will not rise rapidly, and the system will remain normal or only shorten the detection cycle. Conversely, if the conduction ratio of a certain heating zone has decreased, but the corresponding temperature is still rising, and the phase change after the moving average continues to increase, the judgment unit will consider the change to be inconsistent with normal environmental factors, thereby increasing the abnormal judgment value and triggering subsequent protection.

[0089] In this embodiment, there is bidirectional data cooperation between the drive protection module and the anomaly judgment module; the drive protection module provides the anomaly judgment module with the current conduction ratio of each heating zone, and the anomaly judgment module returns a temperature adjustment command or protection command to the drive protection module based on the corrected judgment result; in this way, the heat output status of each heating zone can be correlated with the characteristics of the currently detected abnormal parameters, avoiding ignoring the heating status by relying solely on sensor data.

[0090] The technical advantage of this implementation is that by simultaneously incorporating ambient temperature, ambient humidity, conduction ratio, and reference phase into the correction process, and by performing a moving average on the phase change, the system can still relatively stably distinguish between normal slow changes and local continuous anomalies in humid environments, under thick blankets, or under conditions of large power changes, thereby reducing false alarms while maintaining the ability to identify real heating anomalies.

Claims

1. An electric blanket adaptive temperature regulation and abnormal heating blocking protection system, characterized in that, Includes the electric blanket itself and the controller; The electric blanket body includes at least one heating zone, and each heating zone is provided with a heating wire assembly, a temperature sensor and an AC power device. The heating wire assembly includes an inner heating wire, a temperature-sensing insulation layer covering the outer periphery of the inner heating wire, and a safety signal wire disposed on the outside of the temperature-sensing insulation layer. The controller is electrically connected to a temperature sensor, an AC power device, and a safety signal wire, and includes a setting unit, a detection module, a timing control module, an anomaly judgment module, and a drive protection module. The setting unit is used to receive the input set temperature for each heating zone; The detection module is used to collect zero-crossing signals, temperatures of each heating zone, ambient temperature, ambient humidity, the set temperature, and the coupling signal on the safety signal wire; The timing control module is used to control the AC heating period and shutdown period of each heating zone according to the zero-crossing signal, and to send a detection pulse during the shutdown period to obtain the phase delay amount; The anomaly detection module is used to detect anomalies based on the phase delay, the temperature of each heating zone, the ambient temperature, the ambient humidity, and historical reference data, and output temperature adjustment commands and protection commands. The drive protection module is used to control the conduction ratio of AC power devices in each heating zone according to the temperature adjustment command, and to perform power reduction, time-limited heating, partial power-off, whole-machine power-off, audible and visual alarm and fault recording according to the protection command. The historical baseline data includes at least the baseline phase, phase fluctuation threshold, phase growth threshold, and heating rate threshold.

2. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 1, characterized in that, The detection module includes a zero-crossing detection unit, a temperature detection unit, an environmental detection unit, and a coupling signal detection unit; The zero-crossing detection unit is used to detect the zero-crossing point of the AC mains power and output a synchronization signal to the timing control module; The temperature detection unit is used to acquire the temperature values ​​of the temperature sensors in each heating zone; The environmental detection unit is used to acquire ambient temperature and humidity. The coupling signal detection unit is used to collect the coupling signal on the safety signal wire after the timing control module sends a detection pulse, and send the coupling signal to the timing control module.

3. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 2, characterized in that, The timing control module includes a time-division control unit, a delay waiting unit, a pulse transmission unit, and a phase detection unit; The time-division control unit is used to allocate the on-time and off-time of each heating zone according to the zero-crossing signal. The delay waiting unit is used to perform a delay waiting after the AC power device in the corresponding heating zone is turned off; The pulse sending unit is used to send a detection pulse between the inner heating wire and the safety signal wire of the target heating zone within the time window after the delay waiting unit ends. The phase detection unit is used to determine the phase delay based on the edge timing relationship between the detection pulse and the coupling signal.

4. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 3, characterized in that, The anomaly detection module includes a storage unit, a deviation calculation unit, a judgment unit, and a protection control unit; The storage unit is used to store the initial phase, reference phase, phase fluctuation threshold, phase growth threshold, heating rate threshold, over-temperature threshold, first threshold, second threshold, and continuous triggering set number of times, wherein the first threshold is less than the second threshold; The deviation calculation unit is used to obtain parameters reflecting the phase change state based on the phase delay amount. The parameters of the phase change state include at least the phase change amount of the current detection cycle and the phase change trend of multiple consecutive detection cycles. The determination unit is used to determine the abnormal determination value based on parameters such as temperature information, environmental information, and phase change state. The protection control unit is used to record the number of continuous triggers, compare the anomaly determination value with a first threshold and a second threshold, and perform graded protection based on the number of continuous triggers: When the abnormal judgment value is less than the first threshold, a normal state flag is output and the current conduction ratio is maintained; When the abnormal judgment value reaches the first threshold and is less than the second threshold, an early warning status flag is output, along with a local power reduction command and a shortened detection cycle command. When the abnormal judgment value reaches the second threshold and the number of continuous triggers does not reach the set number of continuous triggers, the warning status mark is maintained and the number of continuous triggers is accumulated. When the temperature of the heating zone reaches the over-temperature threshold and the phase change amount in the parameters of the phase change state reaches the phase fluctuation threshold and / or the phase change trend reaches the phase growth threshold, a serious fault status flag is output, and a power-off command for the entire machine is output.

5. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 4, characterized in that, The drive protection module includes a power control unit, an alarm unit, and a fault recording unit; The power control unit is used to receive temperature adjustment commands and protection commands output by the anomaly judgment module, and to control the on / off state and on / off ratio of the AC power devices in each heating zone. The alarm unit is used to issue an audible and visual alarm when there is a partial power failure or a complete power failure. The fault recording unit is used to record the heating zone where an abnormality occurred, the fault level, the power outage time, and the lockout status.

6. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 4, characterized in that, The anomaly determination value is determined based on the parameters of the phase change state and the heating parameters, combined with the phase fluctuation threshold, phase growth threshold, heating rate threshold and preset weights. Among them, the heating parameter is a parameter that characterizes the rate of temperature change within multiple consecutive detection cycles; The anomaly determination value is determined by the determination unit based on the phase change amount of the current detection cycle, the phase change trend of multiple consecutive detection cycles, and the comprehensive characteristic evaluation of the heating parameters.

7. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 6, characterized in that, When the anomaly detection value of a certain heating zone is less than the first threshold, the reference phase of that heating zone is updated.

8. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 7, characterized in that, Each heating zone is equipped with at least one temperature sensor, which is located on the carpet surface of the corresponding heating zone. The safety signal wire extends along the inner heating wire and wraps around the outside of the temperature-sensing insulation layer. The anomaly detection module obtains the conduction ratio of each heating zone from the drive protection module and reads the reference phase from the historical reference data from the storage unit. The determination unit corrects the parameters of the phase change state and the heating parameters based on the ambient temperature, ambient humidity, the conduction ratio of each heating zone, and the reference phase.

9. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 8, characterized in that, The AC power devices are integrated and packaged inside the controller, or distributed in each heating zone of the electric blanket body and communicate with the controller.

10. The adaptive temperature regulation and abnormal heating protection system for electric blankets according to claim 4, characterized in that, The deviation calculation unit is used to perform a moving average processing on the phase change amount within multiple consecutive detection cycles, and sends the obtained phase change state parameters to the determination unit.

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