Physiotherapy insole with temperature control function and control method thereof

Abstract

The application relates to the technical field of shoe-pad temperature control, in particular to a physiotherapy shoe-pad with a temperature control function and a control method thereof, which comprises the following steps: obtaining a current driving amount output to a heating element and obtaining a temperature value of the heating element after filtering; calculating a temperature difference between two temperature values with a preset time interval; when the driving amount is greater than a preset driving amount threshold value, the temperature difference is negative, and the absolute value of the temperature difference is greater than a preset heat dissipation reference, it is determined that a phase change state is entered; after it is determined that the phase change state is entered, integral operation and differential operation of a preset constant temperature algorithm are suspended, and the driving amount is clamped to a preset safety threshold value; the safety threshold value is adjusted based on a real-time temperature value, so that the temperature value is lower than a preset temperature drift threshold value of the light-emitting element. The application can solve the problems of heat loss of control and light therapy failure caused by sweating, and realizes safe constant temperature physiotherapy.

Description

Technical Field

[0001] This application relates to the technical field of temperature control for insoles, and in particular to a physiotherapy insole with temperature control function and a method for controlling the temperature control thereon. Background Technology

[0002] Smart insoles are commonly used for foot health care and warmth. In actual wear, the soles of the feet are constantly within the enclosed environment of the shoe, subjected to dynamic mechanical pressure, and prone to a rapid increase in local micro-humidity due to sweat gland secretion. Conventional smart insoles typically integrate heating components, phototherapy components, and temperature sensors within their flexible substrate. The system uses real-time data collected by the sensors to execute a closed-loop constant-temperature algorithm to drive the heating element to generate heat, and simultaneously activates light-emitting devices of specific wavelengths to maintain the required ambient temperature and therapeutic light effect for the soles of the feet.

[0003] Chinese invention patent application CN120240760A discloses a temperature-controlled smart insole and its control method. This solution arranges a semiconductor cooler and a patch-type temperature sensor inside the insole substrate. Its control logic acquires the real-time temperature of the insole, calculates the error between the current measured value and the set temperature, and then generates a control signal by combining a proportional-integral-derivative algorithm and a temperature change rate control algorithm. The system dynamically adjusts the output power based on the temperature error value and the temperature change rate, driving the working end to heat up or cool down, so that the surface temperature of the insole is close to the target set value.

[0004] However, this conventional control logic relies on feedback compensation based solely on temperature error and the rate of temperature change, failing to adequately decouple the nonlinear thermodynamic disturbances caused by the coupling of multiple physical fields within the enclosed shoe cavity. In individuals with excessive sweating, under the combined conditions of constant-temperature heat therapy and phototherapy, liquid sweat expelled from the soles of the feet permeates downwards to the surface of the heating element, evaporating within the 37°C to 45°C range and absorbing a large amount of latent heat of vaporization (approximately 2400 kJ / kg), causing a transient negative jump in the local thermodynamic gradient. Limited by the error tracking characteristics of conventional PID closed-loop algorithms, this localized pseudo-cooling caused by physical phase change is misinterpreted by the system as a severe external temperature drop, leading to a continuous increase in the heating power of the heating unit based on the large closed-loop deviation. With continuous high-power injection, once the sweat in the localized area completely evaporates, the phase change heat source disappears abruptly, and the large accumulation of overshoot heat energy at the bottom layer inevitably causes a severe physical overshoot on the surface temperature of the heating layer. The dramatic temperature surge not only triggers local thermal runaway and the risk of burns, but also causes the surface temperature to directly break down the physical red line of the light-emitting device, resulting in a narrowing of the band gap and a red shift in the spectrum, thus causing the targeted therapy function of specific wavelengths to completely fail. Summary of the Invention

[0005] To address the issues of uncontrolled fever and phototherapy failure caused by excessive sweating, and to achieve safe, constant-temperature physiotherapy, this application provides a physiotherapy insole with temperature control function and its control method.

[0006] Firstly, this application provides a control method for a physiotherapy insole with temperature control function, employing the following technical solution: A control method for a physiotherapy insole with temperature control function, wherein the physiotherapy insole includes a main control board, a power supply battery, a heating element, and a light-emitting element, and the control method is executed by the main control board, including: Obtain the current driving quantity output to the heating element, and obtain the filtered temperature value of the heating element; Calculate the temperature difference between two temperature values ​​that are separated by a preset time interval; When the driving quantity is greater than a preset driving quantity threshold, and the temperature difference is negative and the absolute value of the temperature difference is greater than a preset heat dissipation reference, it is determined that the phase transition state has been entered. After determining that the phase transition state has been entered, the integral and differential operations of the preset isothermal algorithm are suspended, and the driving quantity is clamped to a preset safety threshold. The safety threshold is adjusted based on the real-time temperature value to constrain the temperature value from falling below a preset temperature drift threshold of the light-emitting element.

[0007] Optionally, the step of obtaining the filtered temperature value of the heating element includes: The transient temperature of the surface of the heating element is collected at a preset period and then sequentially pressed into the sliding queue. The transient temperatures within the sliding queue are subjected to mean filtering to extract smoothed temperatures; The smoothed temperature is used as the filtered temperature value of the heating element and aligned with the time domain of the drive quantity.

[0008] Optionally, the driving quantity is the duty cycle of the pulse signal; The step of adjusting the safety threshold based on the real-time temperature value includes: Calculate the rate of increase of the real-time temperature value, and calculate the remaining temperature difference between the preset temperature drift threshold and the real-time temperature value; When the remaining temperature difference is greater than the preset safety limit and the rate of rise is greater than zero, the ratio of the rate of rise to the remaining temperature difference is calculated as the dynamic approach gradient, the product of the dynamic approach gradient and the preset conversion coefficient is calculated as the duty cycle reduction amount, and the duty cycle reduction amount is subtracted from the safety threshold. When the remaining temperature difference is greater than the preset safety limit and the rate of rise is less than zero, the product of the absolute value of the rate of rise and the preset recovery coefficient is calculated as the duty cycle callback amount, and the duty cycle callback amount is accumulated to the safety threshold, and the accumulated safety threshold is not greater than the preset benchmark upper limit. When the remaining temperature difference is greater than the preset safety limit and the rate of increase is zero, the safety threshold is maintained; When the remaining temperature difference is not greater than the preset safety limit, the safety threshold is directly set to zero; The duty cycle is clamped with the updated safety threshold to constrain the temperature value to be within a preset tolerance range below the preset temperature drift threshold.

[0009] Optionally, during the clamping of the duty cycle, the method further includes: Calculate the second-order time difference of the temperature value; When the temperature difference is greater than or equal to zero for a preset number of consecutive times and the second-order time difference falls within a preset micro-rise range, or when the duration of clamping the duty cycle reaches a preset protection duration, the duty cycle is set to zero to perform power-off sliding.

[0010] Optionally, after performing the power-off coasting, the method further includes: The temperature difference is continuously calculated, and the duration of the power-off gliding is accumulated. When the duration reaches the preset gliding time and the temperature difference falls into the preset stable zone, or when the duration reaches the preset escape limit duration, the zeroing of the duty cycle and the clamping of the safety threshold are released.

[0011] Optionally, during the clamping of the duty cycle, the method further includes: Calculate the required duty cycle for the corresponding isothermal target; When the temperature value is less than the preset lower limit and the required duty cycle is greater than the safety threshold, power is alternately supplied to the light-emitting element and the heat-generating element according to a preset cycle; When power is supplied to the light-emitting element, the duty cycle output to the heat-generating element is set to zero; When power is supplied to the heating element, the power to the light-emitting element is cut off and the duty cycle is clamped, and the power is output to the heating element at the safety threshold.

[0012] Optionally, during the clamping of the duty cycle, the method further includes: The surface temperature of the power supply battery is collected; When the surface temperature is greater than a preset noise floor threshold, the temperature difference between the surface temperature and the preset noise floor threshold is calculated; The product of the temperature difference and the preset thermal coupling coefficient is used as the bias. The corrected threshold is obtained by subtracting the bias from the safety threshold; When the correction threshold is less than zero, the correction threshold is truncated to zero; The duty cycle is clamped by the modified threshold.

[0013] Optionally, during the acquisition of the surface temperature of the power supply battery, the method further includes: When the surface temperature exceeds a preset power-off threshold, a hardware interrupt is triggered. The power supply to the heating element and the light-emitting element is cut off based on the hardware interrupt; Wherein, the power outage threshold is greater than the preset noise floor threshold.

[0014] Optionally, after cutting off the power supply to the heating element and the light-emitting element, the method further includes: The software is blocked from waking up and its output of the duty cycle is disabled. Clear the transient temperature in the sliding queue; The power supply is kept off until a reset level is detected, at which point the duty cycle is reset.

[0015] Secondly, the present application provides a physiotherapy insole with temperature control function, which adopts the following technical solution: a physiotherapy insole with temperature control function, including a main control board, a power supply battery, a heating element, a light-emitting element, a first temperature sensor and a second temperature sensor; The first temperature sensor is disposed on the surface of the power supply battery to collect the surface temperature of the power supply battery; The second temperature sensor is disposed on the surface of the heating element to collect the transient temperature of the heating element; The main control board is electrically connected to the power supply battery, the heating element, the light-emitting element, the first temperature sensor, and the second temperature sensor, respectively. The main control board is configured to execute the control method described above.

[0016] In summary, this application includes the following beneficial technical effects: 1. By acquiring the driving quantity and the filtered temperature value and calculating the temperature difference, the phase change state is determined when the driving quantity is greater than the driving quantity threshold and the temperature difference is greater than the negative absolute value of the heat dissipation reference. It can distinguish the heat absorption of sweat phase change evaporation from the cooling of the normal environment and the noise of gait compression based on the combination characteristics of the driving energy input and the direction of thermal response. The integral and differential operations are suspended to avoid error accumulation and overcompensation, and the driving quantity is clamped to a safe threshold. This limits the injection of heating power during sweat evaporation, effectively reducing the risk of physical overshoot on the surface of the heating element caused by the accumulation of heat energy after sweat evaporation. This also avoids the failure of phototherapy due to spectral frequency shift caused by the light-emitting element exceeding the preset temperature drift threshold.

[0017] 2. During the clamping duty cycle, the rising rate of the temperature value and the remaining temperature difference are calculated. The dynamic approach gradient is determined based on the ratio of the rising rate to the remaining temperature difference, and the duty cycle is adjusted accordingly. At the same time, a controlled callback mechanism is introduced when the rising rate is less than zero to gradually release the restricted threshold space. Combined with the preset benchmark upper limit, the accumulated safety threshold is truncated, so that the safety threshold can be adjusted bidirectionally with the direction of temperature value change rather than being compressed to zero in one direction. This effectively improves the continuous working capability of the constant temperature algorithm closed loop under the thermal pulsation interference generated by the alternating power supply mode and avoids the control logic from being interrupted due to unidirectional ratchet deadlock.

[0018] 3. When the temperature value is lower than the preset lower limit and the required duty cycle is greater than the safety threshold, power is supplied to the light-emitting element and the heating element alternately according to the preset cycle. When power is supplied to the light-emitting element, the duty cycle output to the heating element is set to zero. When power is supplied to the heating element, the power to the light-emitting element is cut off and the duty cycle is clamped. This separates the heating demand and the light-emitting element's anti-temperature drift demand in the time domain. Under the phase change state, it maintains the heating capacity of sweaty feet and avoids the superposition of light and heat loads at the same time. At the same time, maintaining the clamping state prevents high-frequency oscillation of the control logic, effectively taking into account both constant temperature heating under sweaty conditions and the wavelength stability of the light-emitting element. Attached Figure Description

[0019] Figure 1 A flowchart of the control method provided in the embodiments of this application; Figure 2 This is an exploded view of the structure of the physiotherapy insole provided in an embodiment of this application; Figure 3 This is a circuit connection block diagram of a physiotherapy insole provided in an embodiment of this application; Figure 4 This is a timing diagram showing the alternating power supply to the light-emitting element and the heat-generating element provided in an embodiment of this application. Figure 5 The dynamic adjustment trend chart of the security threshold is provided for the embodiments of this application. Detailed Implementation

[0020] The following combination Figures 1-5 This application will be described in further detail.

[0021] Example 1

[0022] This embodiment discloses a therapeutic insole with temperature control function. The therapeutic insole includes a main control board, a power supply battery, a heating element, a light-emitting element, a first temperature sensor, and a second temperature sensor. The power supply battery is a 2.7mm ultra-thin soft-pack polymer lithium battery with a capacity of 1500mAh and a rated voltage of 3.7V. The power supply battery is fixed in the groove on the inside of the arch of the foot, avoiding the area of ​​repeated bending of the forefoot and the area of ​​heavy pressure on the heel.

[0023] The power supply battery has a built-in BMS protection circuit, which provides overcharge protection, over-discharge protection, short-circuit protection, overcurrent protection, reverse connection protection, and reverse current protection. The main control board is located within the flexible functional layer of the insole's midfoot area. The main control board integrates a charging management circuit, a PWM generator, a constant current drive circuit, a PID temperature control unit, a logic comparator, a hardware interrupt interface, a timing unit, and memory. The charging interface uses a Type-C interface, supplying power to the charging management circuit according to the 5V default current power supply mode in the USB Type-C Cable and Connector Specification.

[0024] like Figure 2 As shown in the structural layering diagram, the insole body is made of a three-layer ultra-thin composite structure through hot pressing. From top to bottom, the upper layer is a skin-friendly, breathable, and sweat-absorbing flexible fabric layer; the middle layer is a functional layer integrating light-emitting components, heating components, a main control board, a first temperature sensor, a second temperature sensor, and flexible wiring; and the bottom layer is a non-slip, wear-resistant, insulating, and cushioning insole layer. The overall finished product thickness is 4.2mm, suitable for shoe sizes 35 to 44. The heating component uses a full-area carbon fiber flexible heating film, covering the main support areas of the forefoot, arch, and heel, and receives the drive output from the main control board through low-voltage PWM pulse signals. The light-emitting component uses a zoned multispectral flexible FPC phototherapy module, with 660nm red LEDs and 415nm light blue LEDs in the forefoot area, 660nm red LEDs and 850nm near-infrared LEDs in the core arch area, and 850nm near-infrared LEDs as the main component in the heel pressure area. The surface of the light-emitting component is covered with a soft light diffusion layer, converting the point light source into a surface light emission, reducing local light hotspots on the skin.

[0025] The first temperature sensor is positioned on the surface of the power supply battery to collect its surface temperature. The second temperature sensor is positioned on the surface of the heating element to collect its transient temperature. Both the first and second temperature sensors are 10kΩ NTC thermistors with a B value of 3950K. The main control board is based on the relationship between the resistance of the NTC thermistor and temperature. Temperature conversion, among which Kelvin temperature, Take 298.15K, Take 10kΩ, The temperature is set at 3950K. The second temperature sensor is attached to the upper surface of the carbon fiber flexible heating film, near the 415nm light blue LED heat-sensitive area on the forefoot. The flexible wiring returns to the main control board along the low-bending stress path of the arch, avoiding the repeated bending line of the metatarsophalangeal joint. The first temperature sensor is attached to the outer surface of the aluminum-plastic film of the power supply battery. The heat-sensitive surface is attached to the power supply battery through a thermally conductive silicone sheet with a thickness of 0.2mm to 0.5mm.

[0026] based on Figure 3 The established star control topology connects the main control board to the power supply battery, heating element, light-emitting element, first temperature sensor, and second temperature sensor via corresponding branches. The drive output from the main control board to the heating element is a pulse signal with a duty cycle; the PWM frequency is set to 200Hz to 1kHz to avoid low-frequency thermal pulsations perceptible to the soles of the feet and to reduce MOSFET switching losses. A constant current drive circuit provides a stable current to the light-emitting element: the operating current for a single 415nm light blue LED is 5mA to 20mA, for a single 660nm red LED it is 5mA to 30mA, and for a single 850nm near-infrared LED it is 10mA to 50mA. The preset temperature drift threshold for the 415nm light blue LED is 43℃, and the preset tolerance range is 1℃ to 2℃ below the preset temperature drift threshold. The setting of safety thresholds and related temperature drift thresholds is based on rigorous semiconductor physics. These thresholds are grounded in the physical law that the bandgap of III-V semiconductor LEDs decreases with increasing temperature. According to Varshni's empirical formula, bandgap contraction will cause a redshift of approximately 0.1 nm / ℃ to 0.2 nm / ℃ in the peak emission wavelength as the junction temperature increases. For the highly targeted 415 nm light blue light, once the local thermal field exceeds 43℃, the accumulated redshift will cause the output wavelength to deviate from the optimal absorption peak for superficial antibacterial effects. This redshift significantly weakens the energy concentration of the target wavelength band. Therefore, strictly clamping the preset temperature drift threshold at 43℃ is essential for maintaining the effectiveness of phototherapy.

[0027] Under standard mass production conditions, combined with Figure 1 The control board executes a control method for a therapeutic insole with temperature control function by controlling the execution and feedback loop jump sequence. The main control board acquires the transient temperature of the heating element surface output by the second temperature sensor at a preset period of 20ms to 100ms and sequentially pushes it into a sliding queue. The sliding queue covers a time window of 1.0s to 1.5s, which covers the periodic contact thermal resistance disturbance caused by the 1Hz to 2Hz gait frequency of normal walking. The main control board performs mean filtering on the transient temperature in the sliding queue, extracts the smoothed temperature, uses the smoothed temperature as the filtered temperature value of the heating element, and aligns it with the driving quantity output to the heating element at the same sampling time in the time domain. Due to the composite thermal resistance formed by the upper breathable and sweat-absorbing flexible fabric layer, the middle functional layer, and the lower insulating and cushioning insole layer, there is a thermal conduction hysteresis of approximately 0.5s to 3s from the second temperature sensor to the foot contact surface. Therefore, the main control board uses a second-level sliding queue rather than a microsecond-level sampling peak as the control basis.

[0028] The main control board acquires the current drive quantity output to the heating element and the filtered temperature value of the heating element. The main control board calculates the temperature difference between two temperature values ​​separated by a preset time interval, which is 2 to 5 seconds. This temperature difference reflects the first-order time change of the heating element's surface temperature within the evaluation window. In a normal dry shoe cavity, when the drive quantity of the heating element is greater than the steady-state heat preservation value, the temperature value should rise or slowly stabilize. In a sweaty foot scenario, sweat penetrates the skin-friendly, breathable, and sweat-absorbing flexible fabric layer and reaches the vicinity of the heating element. When liquid water changes from liquid to gas, it absorbs the latent heat of vaporization. The latent heat of vaporization of water is still close to 2400 kJ / kg in the range of approximately 37°C to 45°C. Local heat is absorbed by the phase change, and the temperature value shows a negative jump opposite to the direction of energy input.

[0029] When the driving quantity exceeds the preset driving quantity threshold, and the temperature difference is negative and its absolute value is greater than the preset heat dissipation benchmark, the main control board determines that it has entered a phase change state. The driving quantity threshold is set to 30% to 40% duty cycle under 3.7V low-voltage power supply conditions, indicating that the heating element is in a region of significant positive heat injection. The heat dissipation benchmark is calibrated based on the natural heat dissipation gradient under no-sweat conditions in the insole, typically ranging from 0.15℃ / s to 0.35℃ / s. Specifically, this value is calculated based on the thermal resistance model of the composite structure of the insole body. The upper skin-friendly, breathable, and sweat-absorbing flexible fabric layer, the middle functional layer, and the lower anti-slip, wear-resistant, insulating, and cushioning pad layer form a series thermal resistance network. Under no-phase-change conditions, the maximum natural heat dissipation rate of the heating element surface is limited by the low thermal conductivity of the anti-slip, wear-resistant, insulating, and cushioning pad layer. Therefore, 0.15℃ / s to 0.35℃ / s is calibrated as the physical heat dissipation limit boundary. When the negative absolute value of the temperature difference crosses this boundary, it can be thermodynamically confirmed that it is not caused by environmental cooling or gait compression, but by an additional cold source of latent heat absorption of vaporization by sweat phase change. This composite condition uses the driving quantity to characterize the energy input and the temperature difference to characterize the direction of the thermal response. Both of these characteristics distinguish between the heat absorption of sweat phase change evaporation and ordinary environmental cooling or gait compression noise, preventing conventional PID thermostatic control units from mistaking the false cooling caused by phase change heat absorption as shoe cavity cooling.

[0030] Upon determining that the phase transition state has been entered, the main control board suspends the integral and differential operations of the preset isothermal algorithm and clamps the drive quantity to a preset safety threshold. The preset isothermal algorithm is a PID isothermal algorithm; the proportional term can still be used for small temperature difference correction, the integral operation is suspended to prevent power stacking caused by long-term error accumulation, and the differential operation is suspended to avoid overcompensation triggered by negative temperature abrupt changes. The safety threshold is initially set to a duty cycle of 15% to 25%, and is lower than the drive quantity before entering the phase transition state. The main control board adjusts the safety threshold based on the real-time temperature value to constrain the temperature value from falling below the preset temperature drift threshold of the light-emitting element.

[0031] The main control board calculates the real-time temperature rise rate and the remaining temperature difference between the preset temperature drift threshold and the real-time temperature. When the remaining temperature difference is greater than the preset safety limit and the rise rate is greater than zero, the main control board calculates the ratio of the rise rate to the remaining temperature difference as the dynamic approach gradient, and calculates the product of the dynamic approach gradient and the preset conversion coefficient as the duty cycle reduction amount, subtracting the duty cycle reduction amount from the safety threshold. When the remaining temperature difference is greater than the preset safety limit and the rise rate is less than zero, the main control board calculates the product of the absolute value of the rise rate and the preset recovery coefficient as the duty cycle correction amount, accumulating the duty cycle correction amount to the safety threshold, and the accumulated safety threshold is not greater than the preset benchmark upper limit. When the remaining temperature difference is greater than the preset safety limit and the rise rate is equal to zero, the main control board maintains the safety threshold unchanged.

[0032] The original logic only had rising polarity interception, which caused the safety threshold to be continuously misjudged and unidirectionally compressed to zero under the thermal pulsation interference generated by the alternating power supply mode. Introducing a controlled callback mechanism when the rising rate is less than zero breaks the unidirectional ratchet deadlock, allowing the system to gradually release the limited threshold space with each temperature decrease. The preset upper limit truncation prevents the risk of overheating, ensuring the sustainable operation of the temperature control algorithm's closed loop. This dynamic approach gradient can be represented as... ,in For the reason The obtained rate of ascent, The current temperature value. This is the temperature value from the previous cycle. For the evaluation time interval; To preset the temperature drift threshold, This is the real-time temperature value. This is the remaining temperature difference.

[0033] Due to the dynamic approach gradient The physical dimension of this is the reciprocal of time. The preset conversion coefficient is set to %·s and is used to map the dynamic approach gradient to a percentage reduction in the duty cycle dimension. The typical range of the preset conversion coefficient is 10%·s to 50%·s. The duty cycle reduction is the sum of the preset conversion coefficient and the time factor. The product of the two values. The preset recovery coefficient is in units of %·s / ℃, with a typical range of 10%·s / ℃ to 20%·s / ℃. The preset upper limit is the initial safety threshold set before entering the phase transition state, for example, a duty cycle of 15% to 25%. When the remaining temperature difference is not greater than the preset safety limit, the main control board directly sets the safety threshold to zero. This segmented mechanism eliminates hardware crashes caused by division-to-zero anomalies when the actual temperature approaches or exceeds the temperature drift threshold. The main control board clamps the duty cycle with the updated safety threshold, constraining the temperature value to remain within a preset tolerance range below the preset temperature drift threshold.

[0034] As an optional implementation, the preset conversion coefficient employs segmented gain adjustment. When the temperature value is more than 3°C below the preset temperature drift threshold, the preset conversion coefficient is set to a small value, such as 10%·s, maintaining the safety threshold at a duty cycle close to the initial 20% to 25%. When the temperature value is 1°C to 3°C below the preset temperature drift threshold, the preset conversion coefficient gradually increases to 20%·s to 30%·s as the temperature difference decreases, thus strengthening the reduction in duty cycle. When the temperature value falls within 1°C below the preset temperature drift threshold and the remaining temperature difference is greater than the preset safety limit, the preset conversion coefficient is adjusted to its maximum, such as 50%·s, ensuring that the calculated reduction in duty cycle is sufficient to quickly limit the safety threshold to a duty cycle of 5% to 10%. The physical significance of this dynamic gain mechanism is to retain a small amount of heat maintenance capability while ensuring that the local thermal field of the 415nm light blue LED does not cross the spectral frequency shift red line.

[0035] During the clamping duty cycle, the main control board calculates the second-order time difference of the temperature value. The second-order time difference is obtained by subtracting two adjacent temperature differences and is used to characterize the acceleration of temperature change. When the temperature difference is greater than or equal to zero for a preset number of consecutive times and the second-order time difference falls within a preset micro-rise interval, or when the duration of the clamping duty cycle reaches a preset protection duration, the main control board sets the duty cycle to zero and performs a power-off sliding operation. The preset number of consecutive times is 3 to 5, and the preset micro-rise interval is 0.005℃ / s. 2 Up to 0.02℃ / s 2 The preset protection duration is set to 120s to 180s. The above control parameter configuration has a suitable theoretical basis in system dynamics. The temperature difference changes from negative to continuously greater than or equal to zero, and the second-order time difference falls precisely into an extremely small micro-rise range. At the physical level, this confirms that the evaporation of liquid sweat on the surface of the heating element has reached the critical depletion point, the phase change heat absorption cold source is about to disappear, and the energy accumulation within the total heat capacity of the system is about to trigger a nonlinear temperature change. By capturing this critical dynamic characteristic and triggering the power-off gliding in advance, subsequent thermal overshoot can be completely blocked. Increasing the preset protection duration serves as a time-dimensional safety net, preventing the system from missing the transient critical condition due to severe gait disturbances and permanently locking in a clamped state. Setting the duty cycle to zero stops the heating element from actively heating. The heating element, flexible fabric layer, and air in the shoe cavity enter the gliding cooling range through heat capacity and natural conduction.

[0036] After power failure coasting is executed, the main control board continuously calculates the temperature difference and accumulates the duration of power failure coasting. The preset coasting time is 10s to 15s. The forced introduction of the preset coasting time establishes a physical buffer period, avoiding the problem that the tiny positive differential immediately after power failure protection is activated will fall directly into the stable zone, causing the protection logic to be short-circuited and broken down.

[0037] When the duration reaches the preset coasting time and the temperature difference falls into the preset stable zone, or when the duration reaches the preset escape limit duration, the main control board releases the clamping of the duty cycle to zero and the safety threshold. The preset stable zone is -0.03℃ / s to 0.03℃ / s, and the duration of falling into the stable zone is 3s to 8s. The preset escape limit duration is 30s to 60s. The forced introduction of the preset escape limit duration as a watchdog-level timeout fallback mechanism eliminates the risk of indefinite low-temperature deadlock in extremely cold external environments where the negative cooling rate continuously falls below the lower limit of the preset stable zone, causing the system to be stuck in a non-heating state indefinitely before falling into the stable zone. After release, the main control board resumes the integral and differential calculations of the preset constant temperature algorithm and outputs the corresponding required duty cycle according to the user-selected low constant temperature of 38℃, medium constant temperature of 42℃, or high constant temperature of 45℃. The high-end constant temperature of 45℃ is only turned on when the 415nm light blue LED in the light-emitting component is not in the on state or the temperature value is far below the preset temperature drift threshold, so as to avoid the conflict between high temperature heat application and blue light spectrum stability.

[0038] During the clamping duty cycle, the main control board calculates the required duty cycle for the corresponding constant temperature target. When the temperature value is lower than the preset lower limit and the required duty cycle is greater than the safety threshold, the main control board alternately supplies power to the light-emitting and heat-generating components according to a preset cycle. The preset lower limit is set to 30℃ to 34℃, and the preset cycle is set to 5s to 20s. Figure 4 In the timing waveform, the mutual exclusion transition logic ensures that when power is supplied to the light-emitting element at a Vcc level, the main control board simultaneously pulls down the duty cycle of the output to the heating element to GND, setting it to zero. The constant current drive circuit supplies power to the 415nm light blue LED and 660nm red LED on the forefoot, maintaining wavelength stability for phototherapy under low thermal field conditions. After a cycle reversal, when power is supplied to the heating element, the main control board disconnects the power to the light-emitting element, pulls it down to GND, and maintains the clamping of the duty cycle of the heating element, outputting to the heating element at a safe threshold. Maintaining the clamping of the duty cycle ensures that the system does not break the clamping state during alternating power supply, avoiding the misjudgment of physical overshoot caused by injecting high power during phase transitions and resulting in a short-term rapid temperature rise. This eliminates the risk of high-frequency oscillation in the control logic, allowing the heating demand under sweating conditions and the temperature drift resistance requirement of the light-emitting element to be separated in the time domain under safe conditions.

[0039] During the clamping duty cycle, the main control board acquires the surface temperature of the power supply battery. When the surface temperature exceeds a preset noise floor threshold, the main control board calculates the temperature difference between the surface temperature and the preset noise floor threshold, and uses the product of the temperature difference and a preset thermal coupling coefficient as the bias. The main control board subtracts the bias from the safety threshold to obtain a correction threshold. When the correction threshold is less than zero, it is truncated to zero to correct the threshold clamping duty cycle. This unsigned integer underflow interception boundary avoids the extreme condition where the safety threshold has been set to zero by the pre-set anti-temperature drift logic, preventing the underlying data structure from overflowing and going out of bounds due to forced subtraction of a positive bias, thus preventing the microcontroller's unsigned register from overflowing and flipping to full-scale full-power rampage. The preset noise floor threshold is set to 42℃ to 45℃, and the preset thermal coupling coefficient is set to 0.3% / ℃ to 1.5% / ℃ duty cycle. This thermal coupling coefficient is derived from the thermal resistance path calibration between the foot arch power supply battery and the middle carbon fiber flexible heating film, and is used to offset the noise thermal crosstalk generated by the high current discharge of the soft-pack lithium battery.

[0040] When the surface temperature exceeds the preset power-off threshold, the hardware interrupt interface corresponding to the first temperature sensor triggers a hardware interrupt. The power-off threshold is 60℃, which is greater than the preset noise floor threshold. Based on the hardware interrupt, the main control board cuts off power to the heating and lighting components, disables software wake-up and disables the duty cycle output, clears the transient temperature in the sliding queue, and maintains the power-off state until a reset level is detected, at which point the duty cycle is reset. The reset level is provided by a Type-C charging insertion, a long press of a physical button, or a BMS recovery signal. After reset, the initial duty cycle value is 0.

[0041] The 415nm light blue LED in the light-emitting component can be replaced with a 275nm UVC antibacterial LED or a narrowband infrared laser, which are equally sensitive to temperature. After the replacement, the main control board will replace the preset temperature drift threshold with the junction temperature limit or peak wavelength drift limit given in the corresponding light-emitting component's datasheet. The drive quantity, temperature value, temperature difference, phase transition state, safety threshold, preset tolerance range, power-off coasting, and hardware interrupt logic in the control method will remain consistent.

[0042] The virtual functional module architecture of this physiotherapy insole can be highly integrated into a feature extraction module, an adaptive temperature control module, and a fault protection module.

[0043] The feature extraction module is responsible for acquiring the underlying state and analyzing its temporal changes. Its inputs are the underlying sensor signals and operating parameters, and its outputs are the current driving quantity output to the heating element, the filtered temperature value of the heating element, the surface temperature of the power supply battery, and the temperature difference and second-order time difference calculated from the continuous temperature values.

[0044] The adaptive temperature control module, as the core control engine of the system, takes the aforementioned driving quantity, temperature difference, real-time temperature value, and various preset control boundaries (including driving quantity threshold, heat dissipation reference, preset temperature drift threshold, etc.) as inputs. Its output includes the phase change state determination result, the suspension flag of the integral and differential operations of the preset constant temperature algorithm, the safety threshold updated after dynamic approach gradient adjustment, the clamped duty cycle, and the time-sharing power supply status of the light-emitting and heat-generating components that constrain photothermal conflicts.

[0045] The fault protection module is used for multiple defenses under extreme operating conditions. Its inputs are the temperature difference, second-order time difference, surface temperature and preset protection boundary parameters (including preset noise floor threshold, preset thermal coupling coefficient, power failure threshold, etc.). Its outputs are the corrected threshold after bias subtraction, the zero duty cycle and clamp release signal triggered when power failure coasting is executed under preset conditions, the power cut-off signal triggered by hardware interrupt, and the duty cycle after reset based on the reset level response.

[0046] The physical hardware architecture of this therapeutic insole includes a processor, memory, communication interface, PWM generator, constant current drive circuit, MOS power switch, charging management circuit, BMS protection circuit, power supply battery, heating element, light-emitting element, first temperature sensor, and second temperature sensor. The processor uses a low-power MCU, operating at 3.3V, and integrates a 12-bit ADC, timer, GPIO interrupt pin, and PWM peripherals. The memory includes on-chip Flash and SRAM. The Flash stores preset temperature drift threshold, drive quantity threshold, heat dissipation reference, preset micro-rise range, preset noise floor threshold, power-off threshold, preset thermal coupling coefficient, preset recovery coefficient, preset reference upper limit, preset escape limit duration, and user mode parameters. The SRAM stores a sliding queue, temperature difference, second-order time difference, and safety threshold. The communication interface includes a Type-C charging interface and a button input interface. The aforementioned virtual function modules are implemented by the processor reading and executing the computer program in the memory.

[0047] Example 2

[0048] Based on the hardware structure of Example 1, this embodiment reserves a BLE Bluetooth point on the main control board and integrates a low-power Bluetooth communication unit. Users can adjust temperature, dimming, timing, and read usage data via a mobile app. The Bluetooth communication unit conforms to the Bluetooth Core Specification 5.0 and uses the Generic Attribute Profile (GATT) data model. The main control board acts as the GATT Server, and the mobile app acts as the GATT Client. Temperature control targets, light therapy modes, timer durations, low battery reminder thresholds, historical temperature curves, and fault states are mapped to characteristics. These characteristics are identified using a 16-bit or 128-bit Universally Unique Identifier (UUID). Write permissions are used for temperature, dimming, and timing configuration, while notification permissions are used for uploading temperature values, surface temperatures, duty cycles, safety thresholds, and hardware interrupt status.

[0049] In this embodiment, the therapeutic insole includes a main control board, a power supply battery, a heating element, a light-emitting element, a first temperature sensor, and a second temperature sensor. The first temperature sensor is disposed on the surface of the power supply battery to collect the surface temperature of the battery. The second temperature sensor is disposed on the surface of the heating element to collect the transient temperature of the heating element. The main control board is electrically connected to the power supply battery, the heating element, the light-emitting element, the first temperature sensor, and the second temperature sensor. The heating element is a full-area carbon fiber flexible heating film, and the light-emitting element is a zoned multispectral flexible FPC phototherapy module with 660nm red light and 415nm light blue light in the forefoot, 660nm red light and 850nm near-infrared light in the arch, and 850nm near-infrared light in the heel. The power supply battery is a 2.7mm ultra-thin soft-pack 1500mAh lithium battery, hidden and fixed in the groove position on the inside of the arch. The main control board is configured to execute the control method of the therapeutic insole with temperature control function.

[0050] The main control board independently executes local temperature control closed-loop in both BLE connected and disconnected states. The BLE Bluetooth communication unit only changes preset parameters or reads operating data and does not participate in the highest priority decisions regarding safety thresholds, hardware interrupts, and power-off coasting. Users can select pure zone multispectral phototherapy mode, red light plus infrared dual-depth maintenance mode, phototherapy plus low-temperature constant temperature linkage mode, phototherapy plus medium-temperature maintenance linkage mode, phototherapy plus high-temperature cold dispelling linkage mode, or independent full-area hot compress mode via a mobile app. The main control board converts the user mode into constant temperature target, light-emitting element channel current, and timed shutdown duration. The low-temperature constant temperature target is 38℃, the medium-temperature maintenance constant temperature target is 42℃, and the high-temperature cold dispelling constant temperature target is 45℃. When the 415nm light blue LED is on, the main control board covers the user's high-temperature configuration with a preset temperature drift threshold of 43℃ and a preset tolerance range of 1℃ to 2℃, ensuring that the temperature near the heating element does not exceed the blue light spectrum frequency shift boundary.

[0051] The control method is executed by the main control board. The main control board acquires the current drive quantity output to the heating element and the filtered temperature value of the heating element. The drive quantity is the duty cycle of the pulse signal. The second temperature sensor collects the transient temperature of the heating element surface at a preset period of 50ms, and the main control board sequentially pushes it into the sliding queue. The length of the sliding queue is 20 to 30 sampling points, corresponding to a mechanical noise coverage window of 1.0s to 1.5s. The main control board performs mean filtering on the transient temperature in the sliding queue, extracts the smoothed temperature, uses the smoothed temperature as the filtered temperature value of the heating element, and performs time-domain alignment with the drive quantity. Time-domain alignment uses the same system tick counter for marking, and the difference between the duty cycle update time and the temperature value enqueue time is less than one preset period.

[0052] The main control board calculates the temperature difference between two temperature values ​​separated by a preset time interval. The preset time interval is 3 seconds, and the temperature difference is the current smoothed temperature minus the smoothed temperature 3 seconds ago. This temperature difference is input to a logic comparator. The logic comparator uses whether the current duty cycle is greater than the drive quantity threshold as the action feedback condition, and whether the temperature difference is negative and its absolute value is greater than the heat dissipation reference as the thermodynamic feedback condition. The drive quantity threshold is set to a 35% duty cycle, and the heat dissipation reference is set to 0.25℃ / s. When both conditions are met, the main control board determines that it has entered a phase transition state. This determination corresponds to the scenario of liquid sweat evaporation and heat absorption in the closed shoe cavity of a person with excessive sweating. The latent heat of sweat evaporation causes the surface temperature of the heating element to continue to change negatively during continuous energy input. If a normal PID constant temperature algorithm continues to perform integral and differential compensation, it will push up the duty cycle and cause thermal overshoot when the sweat dries.

[0053] After determining that a phase transition state has been entered, the main control board suspends the integral and differential operations of the preset isothermal algorithm and clamps the driving quantity to a preset safety threshold. The initial value of the safety threshold is set to a 20% duty cycle. The main control board adjusts the safety threshold based on the real-time temperature value to constrain the temperature value from falling below the preset temperature drift threshold of the light-emitting component. The main control board calculates the rate of increase of the real-time temperature value and the remaining temperature difference between the preset temperature drift threshold and the real-time temperature value.

[0054] Combination Figure 5The system exhibits a stepped dynamic adjustment trend. When the remaining temperature difference exceeds the preset safety limit and the rate of increase is greater than zero, the main control board calculates the ratio of the rate of increase to the remaining temperature difference as the dynamic approach gradient. The product of the dynamic approach gradient and the preset conversion coefficient is used as the duty cycle reduction amount, which is then progressively subtracted from the safety threshold. When a temporary temperature drop occurs due to environmental factors, i.e., the remaining temperature difference exceeds the preset safety limit and the rate of increase is less than zero, the main control board calculates the product of the absolute value of the rate of increase and the preset recovery coefficient as the duty cycle callback amount. This callback amount is accumulated in a stepped manner to the safety threshold, and the accumulated safety threshold is capped at the preset upper limit. When the remaining temperature difference exceeds the preset safety limit and the rate of increase is zero, the safety threshold remains unchanged; when the remaining temperature difference is not greater than the preset safety limit, the main control board sets the safety threshold directly to zero. The negative polarity callback compensation for the rate of increase breaks the unidirectional ratchet deadlock caused by the alternating time-sharing power supply ripple continuously pressing the safety threshold downwards. The preset safety limit is 0.5℃, the preset conversion coefficient is 20%·s, the preset recovery coefficient is 15%·s / ℃, and the preset upper limit of the baseline is 20% duty cycle.

[0055] The main control board clamps the duty cycle with an updated safety threshold to constrain the temperature value to within a preset tolerance range below the preset temperature drift threshold. When the temperature is 40℃ and the rise rate is 0.05℃ / s, the calculated duty cycle reduction is small, and the safety threshold can be basically maintained at a 20% duty cycle. When the temperature rises to 42℃ and still has a positive upward trend, the ratio increases rapidly due to the shrinking residual temperature difference. The dynamic approach gradient drives a surge in the duty cycle reduction, and the safety threshold is quickly reduced to a 10% to 15% duty cycle. When the temperature drops due to time-sharing fluctuations (rise rate less than zero), the safety threshold is controlled to rebound and release without exceeding the 20% baseline upper limit. When the temperature reaches above 42.5℃ and the residual temperature difference is not greater than the preset safety limit, the safety threshold is directly set to zero.

[0056] The user-defined constant temperature target written in the Bluetooth Low Energy General Attribute Profile (BLE GATT) is used only as input for duty cycle calculation. The main control board sets the preset temperature drift threshold, power failure threshold, preset micro-rise range, and preset noise floor threshold as non-writable characteristics. The mobile app can only read these security parameters and cannot overwrite them. This field permission design ensures that remote temperature adjustment does not compromise the local hardware security boundaries.

[0057] During the clamping duty cycle, the main control board calculates the second-order time difference of the temperature value. This second-order time difference is the difference between the current temperature difference and the temperature difference in the previous evaluation window, divided by a preset duration, and is used to characterize the curvature of the temperature curve on the surface of the heating element. When the temperature difference is greater than or equal to zero for a preset number of consecutive times and the second-order time difference falls within a preset micro-rise range, or when the duration of the clamping duty cycle reaches a preset protection duration, the main control board sets the duty cycle to zero and performs a power-off sliding operation. The preset number of consecutive times is 3, and the preset micro-rise range is 0.01℃ / s. 2 The preset protection duration is 120 seconds.

[0058] During power-off gliding, the PWM generator outputs a low level, the MOS power switch is turned off, and the heat-generating components passively dissipate heat only through their own thermal capacity, the flexible fabric layer, and the air inside the shoe cavity. After power-off gliding is performed, the main control board continuously calculates the temperature difference and accumulates the duration of power-off gliding. When the duration reaches the preset gliding time and the temperature difference falls into the preset stable zone, or when the duration reaches the preset escape limit duration, the main control board releases the clamping of the duty cycle to zero and the safety threshold. The preset gliding time is 10s, the preset stable zone is -0.02℃ / s to 0.02℃ / s, the maintenance time is 5s, and the preset escape limit duration is 45s. The addition of a timeout watchdog timer for the preset escape limit duration avoids the problem of indefinite deadlock caused by excessively rapid temperature drop in extremely cold environments, preventing the shoe from reaching the stable zone.

[0059] During the clamping duty cycle, the main control board calculates the required duty cycle for the corresponding constant temperature target. When the temperature is below the preset lower limit and the required duty cycle is above the safety threshold, the main control board alternately supplies power to the light-emitting and heat-generating components according to a preset cycle. The preset lower limit is 32℃, and the preset cycle is 10s. When powering the light-emitting component, the duty cycle output to the heat-generating component is set to zero, and the constant current drive circuit supplies power to the 415nm light blue LED and the 660nm red LED, maintaining spectral stability in the low thermal field. When powering the heat-generating component, the light-emitting component is de-energized and maintains the clamping of the duty cycle, outputting power to the heat-generating component at the safety threshold. Although the calculated required duty cycle may reach 40% to 70% at this time, it is actually clamped within the safety threshold, avoiding the instantaneous high-power input when the clamping defense is released. This time-division power supply method, while maintaining system stability, ensures that blue light antibacterial and safe cold-dispelling do not overlap in heat load within the same time frame. It resolves the photothermal constraints formed by the closed shoe cavity, sweat phase change, and blue light temperature drift, and avoids the dead loop of control oscillation.

[0060] During the clamping duty cycle, the main control board acquires the surface temperature of the power supply battery. When the surface temperature exceeds a preset noise floor threshold, the main control board calculates the temperature difference between the surface temperature and the preset noise floor threshold, and uses the product of the temperature difference and a preset thermal coupling coefficient as the bias. The main control board subtracts the bias from the safety threshold to obtain a correction threshold. When the correction threshold is less than zero, it is truncated to zero to correct the threshold clamping duty cycle. The preset noise floor threshold is 44℃, and the preset thermal coupling coefficient is 1% duty cycle / ℃. For example, when the surface temperature is 48℃, the temperature difference is 4℃, and the bias is 4% duty cycle. If the original safety threshold was 20% duty cycle, the correction threshold is 16% duty cycle. If the safety threshold was previously set to zero, the calculated -4% duty cycle will be strictly truncated to 0% duty cycle because it is less than zero, ensuring that the unsigned integer duty cycle register does not experience abnormal full-load underflow. This feedforward subtraction cancels out thermal crosstalk generated by the power supply battery during Bluetooth communication, full load of the light-emitting components, and high duty cycle operation of the heat-generating components.

[0061] A hardware interrupt is triggered when the surface temperature exceeds a preset power-off threshold. The power-off threshold is 60℃ and is greater than a preset noise floor threshold. The main control board cuts off power to the heat-generating and light-emitting components based on the hardware interrupt, disables software wake-up and disables the output duty cycle, clears the transient temperature in the sliding queue, and maintains the power-off state until a reset level is detected, at which point the duty cycle is reset. The BLE Bluetooth communication unit can only broadcast fault indicators in the power-off state; it is not allowed to release the power-off state via a mobile app. The reset level is determined by a 10-second long press of a physical button, a detection signal inserted by the charging management circuit, or a BMS recovery signal.

[0062] When the power supply battery is removed and replaced with USB 5V wired low-voltage power supply, the first temperature sensor and the battery noise feedforward cancellation logic are shielded. The main control board retains the second temperature sensor, heating element, light-emitting element, drive quantity, temperature value, temperature difference, phase transition state, safety threshold, preset temperature drift threshold, second-order time difference, and power-off sliding logic. An electronic fuse and current-limiting switch are added to the USB input terminal, with the current limit value set to 1A to 2A. The main control board uses the surface temperature of the power supply battery instead of the temperature sensor near the USB input terminal as the thermal safety input for the cable interface. When the interface temperature exceeds 70°C, a hardware interrupt is triggered, and the power supply to the heating element and light-emitting element is cut off.

[0063] The virtual functional module architecture of this embodiment can be highly integrated into a communication interaction module, a phase transition determination module, and a safety fallback module.

[0064] The communication and interaction module is responsible for receiving external parameters, acquiring the underlying state, and extracting time-domain variation characteristics. Its inputs are the underlying sensor signals and operating parameters such as two temperature values ​​spaced at a preset time interval; its outputs are the constant temperature target received from Bluetooth, the current of the light-emitting element channel, the timing duration, the current driving quantity output to the heating element, the filtered temperature value of the heating element, the surface temperature of the power supply battery, the temperature difference, and the second-order time difference.

[0065] The phase change determination module, as the core control engine of the system, takes the aforementioned driving quantity, temperature difference, real-time temperature value, and various preset control boundaries (including driving quantity threshold, heat dissipation reference, preset temperature drift threshold, preset safety limit, preset conversion coefficient, preset recovery coefficient, preset reference upper limit and preset lower limit, etc.) as input, as well as the aforementioned constant temperature target. Its output includes the phase change state determination result, integral and differential operation suspension flags, updated safety threshold, demand duty cycle, and power supply status of the light-emitting element and the heat-generating element.

[0066] The safety fallback module is used for multiple defenses and anomaly reporting under extreme operating conditions. Its inputs are the surface temperature, temperature difference, and preset protection boundary parameters (including preset noise floor threshold, preset thermal coupling coefficient, power failure threshold, duration, preset coasting time, preset escape limit duration, preset stable zone, etc.). Its outputs are bias and correction threshold, clamp release flag, power cut-off signal, wake-up prohibition flag, and BLE fault status data packet.

[0067] The physical hardware architecture of this embodiment includes a processor, memory, communication interface, BLE Bluetooth communication unit, PWM generator, constant current drive circuit, MOS power switch, ADC sampling circuit, charging management circuit, BMS protection circuit, power supply battery, heating element, light-emitting element, first temperature sensor, and second temperature sensor. The processor uses a low-power 32-bit MCU with an on-chip ADC resolution of 12 bits or higher. A timer is used to generate PWM pulse signals from 200Hz to 1kHz. The GPIO interrupt pin is connected to the hardware comparison output of the first temperature sensor. The memory includes Flash, SRAM, and an erasable parameter area. Flash stores the computer program, SRAM stores the sliding queue and running variables, and the erasable parameter area stores user mode, timing duration, constant temperature target, and historical fault codes. The communication interface includes a Type-C interface, a button interface, and a BLE antenna matching network.

[0068] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for controlling the temperature of a therapeutic insole, characterized in that, The therapeutic insole includes a main control board, a power supply battery, a heating element, and a light-emitting element. The control method is executed by the main control board and includes: Obtain the current driving quantity output to the heating element, and obtain the filtered temperature value of the heating element; Calculate the temperature difference between two temperature values ​​that are separated by a preset time interval; When the driving quantity is greater than a preset driving quantity threshold, and the temperature difference is negative and the absolute value of the temperature difference is greater than a preset heat dissipation reference, it is determined that the phase transition state has been entered. After determining that the phase transition state has been entered, the integral and differential operations of the preset isothermal algorithm are suspended, and the driving quantity is clamped to a preset safety threshold. The safety threshold is adjusted based on the real-time temperature value to constrain the temperature value from falling below a preset temperature drift threshold of the light-emitting element.

2. The control method for a physiotherapy insole with temperature control function according to claim 1, characterized in that, The step of obtaining the filtered temperature value of the heating element includes: The transient temperature of the surface of the heating element is collected at a preset period and then sequentially pressed into the sliding queue. The transient temperatures within the sliding queue are subjected to mean filtering to extract smoothed temperatures; The smoothed temperature is used as the filtered temperature value of the heating element and aligned with the time domain of the drive quantity.

3. The control method for a physiotherapy insole with temperature control function according to claim 2, characterized in that, The driving quantity is the duty cycle of the pulse signal; The step of adjusting the safety threshold based on the real-time temperature value includes: Calculate the rate of increase of the real-time temperature value, and calculate the remaining temperature difference between the preset temperature drift threshold and the real-time temperature value; When the remaining temperature difference is greater than the preset safety limit and the rate of rise is greater than zero, the ratio of the rate of rise to the remaining temperature difference is calculated as the dynamic approach gradient, the product of the dynamic approach gradient and the preset conversion coefficient is calculated as the duty cycle reduction amount, and the duty cycle reduction amount is subtracted from the safety threshold. When the remaining temperature difference is greater than the preset safety limit and the rate of rise is less than zero, the product of the absolute value of the rate of rise and the preset recovery coefficient is calculated as the duty cycle callback amount, and the duty cycle callback amount is accumulated to the safety threshold, and the accumulated safety threshold is not greater than the preset benchmark upper limit. When the remaining temperature difference is greater than the preset safety limit and the rate of increase is zero, the safety threshold is maintained; When the remaining temperature difference is not greater than the preset safety limit, the safety threshold is directly set to zero; The duty cycle is clamped with the updated safety threshold to constrain the temperature value to be within a preset tolerance range below the preset temperature drift threshold.

4. The control method for a physiotherapy insole with temperature control function according to claim 3, characterized in that, During the clamping of the duty cycle, it also includes: Calculate the second-order time difference of the temperature value; When the temperature difference is greater than or equal to zero for a preset number of consecutive times and the second-order time difference falls within a preset micro-rise range, or when the duration of clamping the duty cycle reaches a preset protection duration, the duty cycle is set to zero to perform power-off sliding.

5. The control method for a physiotherapy insole with temperature control function according to claim 4, characterized in that, After performing the power-off coasting, the following is also included: The temperature difference is continuously calculated, and the duration of the power-off gliding is accumulated. When the duration reaches the preset gliding time and the temperature difference falls into the preset stable zone, or when the duration reaches the preset escape limit duration, the zeroing of the duty cycle and the clamping of the safety threshold are released.

6. The control method for a physiotherapy insole with temperature control function according to claim 3, characterized in that, During the clamping of the duty cycle, it also includes: Calculate the required duty cycle for the corresponding isothermal target; When the temperature value is less than the preset lower limit and the required duty cycle is greater than the safety threshold, power is alternately supplied to the light-emitting element and the heat-generating element according to a preset cycle; When power is supplied to the light-emitting element, the duty cycle output to the heat-generating element is set to zero; When power is supplied to the heating element, the power to the light-emitting element is cut off and the duty cycle is clamped, and the power is output to the heating element at the safety threshold.

7. The control method for a physiotherapy insole with temperature control function according to claim 3, characterized in that, During the clamping of the duty cycle, it also includes: The surface temperature of the power supply battery is collected; When the surface temperature is greater than a preset noise floor threshold, the temperature difference between the surface temperature and the preset noise floor threshold is calculated; The product of the temperature difference and the preset thermal coupling coefficient is used as the bias. The corrected threshold is obtained by subtracting the bias from the safety threshold; When the correction threshold is less than zero, the correction threshold is truncated to zero; The duty cycle is clamped by the modified threshold.

8. The control method for a physiotherapy insole with temperature control function according to claim 7, characterized in that, During the acquisition of the surface temperature of the power supply battery, the following is also included: When the surface temperature exceeds a preset power-off threshold, a hardware interrupt is triggered. The power supply to the heating element and the light-emitting element is cut off based on the hardware interrupt; Wherein, the power outage threshold is greater than the preset noise floor threshold.

9. The control method for a physiotherapy insole with temperature control function according to claim 8, characterized in that, After cutting off the power supply to the heating element and the light-emitting element, the method further includes: The software is blocked from waking up and its output of the duty cycle is disabled. Clear the transient temperature in the sliding queue; The power supply is kept off until a reset level is detected, at which point the duty cycle is reset.

10. A therapeutic insole with temperature control function, characterized in that, Includes main control board, power supply battery, heating element, light-emitting element, first temperature sensor and second temperature sensor; The first temperature sensor is disposed on the surface of the power supply battery to collect the surface temperature of the power supply battery; The second temperature sensor is disposed on the surface of the heating element to collect the transient temperature of the heating element; The main control board is electrically connected to the power supply battery, the heating element, the light-emitting element, the first temperature sensor, and the second temperature sensor, respectively. The main control board is configured to perform the control method as described in any one of claims 1 to 9.

Images