Automobile seat heating control method and system

Abstract

The present invention discloses a method and system for controlling heating of automobile seats, comprising the following steps: sampling data fed back by a temperature sensor, and calculating the sampled data to obtain an average value; if the average value is within a preset first threshold range, turning off the heating module; if the average value is within a preset second threshold range, obtaining the sampling temperature corresponding to the average value as the current sampling temperature; setting a target temperature to compare with the current sampling temperature, substituting the target temperature and the current sampling temperature into a PID algorithm, calculating the PID output value, and calculating and obtaining a PWM duty cycle value for controlling heating according to the PID output value; and converting a signal corresponding to the PWM duty cycle value into a low-frequency on-off signal to control the power supply of the heating wire through a high-frequency PWM to low-frequency on-off algorithm. The amount of data for adjusting parameters in the calibration process of seat heating is reduced, and pulse radiation generated by high-frequency PWM is avoided while achieving adaptive temperature regulation.

Description

Technical Field

[0001] The invention relates to the field of temperature control of a heating system, and in particular to a method and system for controlling heating of a car seat. Background Art

[0002] Traditional old-fashioned car seat heating systems without temperature sensors usually have two ways to achieve the heating temperature adjustment function. The first is to control the output of heating power by outputting different PWM signals by presetting different heating gears through the electronic control unit. The second is to control the on and off of the relay and control different on and off durations. This control method without a temperature sensor cannot obtain the current real-time temperature of the seat, so it cannot change the control signal in real time to accurately control the temperature of the seat within a certain temperature range. The change in ambient temperature has a great influence on the temperature control effect. When the ambient temperature is too low, the seat dissipates heat too quickly and the seat cannot be heated. When the ambient temperature is relatively high or the seat has good thermal insulation performance, the seat dissipates heat slowly. This heating method will cause the temperature to be too high and scald the passengers. Therefore, the mainstream car seat heating systems nowadays are equipped with temperature sensors (NTC for short). Car seat heating systems with temperature sensors usually have two ways to achieve the heating temperature adjustment function. The first is to collect the real-time temperature through the MCU, compare the real-time temperature with the preset temperature, and control the opening and closing of the relay. The second is to collect the real-time temperature through the MCU, compare the real-time temperature with the preset temperature, and control the on and off of the high-side switch chip. The method used in this article is the second implementation method, because the high-side switch chip is smaller than the relay, the circuit is simple and easy to integrate into the MCU circuit board, the cost is low, and the control is relatively easy. The electrical schematic diagram is as follows Figure 2 shown.

[0003] There are usually two methods for adjusting the temperature of the existing heating control system with NTC temperature sensor and high-side switch. The first method is that the MCU compares the NTC feedback temperature with the preset temperature. When the NTC feedback temperature is greater than the preset target temperature and exceeds a certain threshold (such as 2 degrees), the high-side switch is turned off for power supply; when the NTC feedback temperature is less than the preset target temperature and exceeds a certain threshold, the high-side switch is controlled to supply power to the heating wire; so that the NTC temperature fluctuates up and down according to a certain threshold (such as 2 degrees) within the preset temperature range. The disadvantage of this control method is that if only one threshold (such as 2 degrees) is set, the temperature fluctuates up and down at the same threshold when heating at different heating gears (with different preset target temperatures), and the threshold cannot be adjusted according to the ambient temperature. This will cause a greater impact on the control effect of the seat surface temperature at different ambient temperatures, because when the ambient temperature is very low, the heat dissipation is faster. If the NTC sensitivity is not enough and the fluctuation threshold is set unreasonably, the surface temperature control of the seat at different gears will be unsatisfactory, and adaptive adjustment cannot be achieved. In order to achieve adaptive adjustment, the second implementation method is to use the NTC temperature and preset temperature collected by the MCU as the input of the PID algorithm for PID calculation, and convert the PID calculation result into PWM output to control the on and off of the high-side switch chip, so that the seat surface temperature can be controlled very stably. However, high-frequency PWM (such as 10HZ) on and off control of high-power devices such as heating wires will generate pulse radiation, and the EMC test cannot pass. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the current field of heating system temperature control, the present invention provides a method and system for controlling automobile seat heating, which reduces the amount of data for adjusting parameters in the seat heating calibration process and avoids pulse radiation generated by high-frequency PWM while achieving adaptive temperature regulation.

[0005] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0006] A method for controlling heating of a car seat, wherein a heating module and a temperature sensor are arranged in the car seat, and the temperature sensor is used to collect the temperature of the heating module and feed back data, comprising the following steps:

[0007] The data fed back by the temperature sensor are sampled multiple times within a preset time interval, and the sampled data are calculated to obtain an average value;

[0008] If the average value is within a preset first threshold range, turning off the heating module;

[0009] If the average value is within the preset second threshold range, the sampling temperature corresponding to the average value is obtained according to the average value as the current sampling temperature;

[0010] Set the target temperature to compare with the current sampling temperature, substitute the target temperature and the current sampling temperature into the PID algorithm, calculate and obtain the PID output value, and calculate and obtain the PWM duty cycle value for controlling heating according to the PID output value;

[0011] If the PWM duty cycle value is higher than the preset PWM upper limit value, the heating module accelerates heating;

[0012] If the PWM duty cycle value is lower than the preset PWM lower limit value, the heating module turns off the heating.

[0013] According to one aspect of the present invention, the preset first threshold range is less than 160 or greater than 3920; the preset second threshold range is between 160 and 3920.

[0014] According to one aspect of the present invention, if the average value is less than 160 or greater than 3920, the temperature sensor is set to a short circuit or open circuit state, and the heating power supply PWM signal is set to 0, and the heating is turned off; if the average value is between 160 and 3920, the temperature sensor is set to a normal state, and the next step is performed.

[0015] According to one aspect of the present invention, the data fed back by the temperature sensor is sampled multiple times within a preset time interval, and the sampled data is calculated to obtain an average value. If the average value is within a preset second threshold range, the sampling temperature corresponding to the average value is obtained as the current sampling temperature based on the average value. If the elapsed time does not meet the preset time, the above steps are continued until the above steps have passed the complete preset time.

[0016] According to one aspect of the present invention, the target temperature is set to be compared with the current sampling temperature, and the target temperature and the current sampling temperature are substituted into the PID algorithm to calculate and obtain the PID output value, and the PWM duty cycle value for controlling the heating is calculated and obtained based on the PID output value. Specifically, a high-frequency PWM to low-frequency on-off algorithm is used to convert the signal corresponding to the PWM duty cycle value into a low-frequency on-off signal to control the power supply of the heating module.

[0017] According to one aspect of the present invention, the preset PWM upper limit value is set to 60; the preset PWM lower limit value is set to 40.

[0018] According to one aspect of the present invention, if the PWM duty cycle value is between a preset PWM upper limit value and a preset PWM lower limit value, the power supply output state of the heating module remains unchanged, and a certain time is set to clear all values ​​and reassign them.

[0019] According to one aspect of the present invention, after setting a certain time to clear all values ​​and re-assign them, return to the step of sampling the data fed back by the temperature sensor multiple times within a preset time interval, calculate the sampled data to obtain an average value, and loop through subsequent steps.

[0020] According to one aspect of the present invention, the steps of the PID algorithm are: turn on heating; execute the PID algorithm; output the power supply PWM duty cycle through the output value of the PID algorithm; convert the power supply switch state according to the PWM duty cycle; the power supply switch state controls the heating of the heating wire; the temperature sensor feeds back the temperature of the heating wire; feeds back to execute the PID algorithm and loop the steps.

[0021] A car seat heating control system, comprising:

[0022] A temperature sensing module is used to collect the temperature of the heating module in the seat;

[0023] A calculation module, used for calculating the average value of the data fed back by the temperature sensor module;

[0024] A conversion module, used to convert the average value into the corresponding current sampling temperature;

[0025] PID algorithm module, sets the target temperature to compare with the current sampling temperature, substitutes the target temperature and the current sampling temperature into the PID algorithm to calculate and obtain the PID output value, and calculates the corresponding power supply PWM duty cycle value through the PID output value;

[0026] The high-frequency PWM to low-frequency on-off algorithm module is used to convert the PWM duty cycle value into a low-frequency on-off signal to control the power supply of the heating wire.

[0027] The advantages of the present invention are as follows: by sampling the data fed back by the temperature sensor multiple times within one second, and calculating the average value of the sampled data; judging whether the average state of the sampled data is normal; if the average state is normal, obtaining the corresponding current sampling temperature according to the average value; setting the target temperature to compare with the current sampling temperature, and substituting the target temperature and the current sampling temperature into the PID algorithm, calculating and obtaining the PID output value; calculating and obtaining the PWM duty cycle value for controlling heating according to the PID output value; and converting the signal corresponding to the PWM duty cycle value into a low-frequency on-off signal to control the power supply of the heating wire through the high-frequency PWM to low-frequency on-off algorithm. The amount of data for adjusting the parameters in the seat heating calibration process is reduced, and pulse radiation generated by high-frequency PWM is avoided while achieving adaptive temperature regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A logic flow chart of a vehicle seat heating control method and system according to the present invention;

[0030] Figure 2 It is an electrical schematic diagram of the prior art of a method and system for controlling heating of an automobile seat according to the present invention;

[0031] Figure 3 A comparison effect diagram of high-frequency PWM control and low-frequency on-off control of a vehicle seat heating control method and system according to the present invention;

[0032] Figure 4 This is an effect diagram of setting different upper and lower parameters of PWM of a car seat heating control method and system according to the present invention;

[0033] Figure 5 It is a principle block diagram of a PID algorithm of a vehicle seat heating control method and system according to the present invention;

[0034] Figure 6 It is a NTC curve diagram of a vehicle test of a vehicle seat heating control method and system according to the present invention;

[0035] Figure 7 The present invention provides a seat surface temperature curve diagram of the actual control of the vehicle seat heating control method and system. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Embodiment 1:

[0038] like Figure 1 As shown, a method for controlling heating of a car seat is provided, wherein a heating module and a temperature sensor are arranged in the car seat, and the temperature sensor is used to collect the temperature of the heating module and feed back data, comprising the following steps:

[0039] S1: Sample the AD value of the data fed back by the temperature sensor 10 times within one second, and calculate the average value of the sampled data.

[0040] S2: If the average value is within a preset first threshold range, turning off the heating module.

[0041] In this embodiment, the preset first threshold range is less than 160 or greater than 3920. If the average value is less than 160 or greater than 3920, the temperature sensor is set to a short circuit or open circuit state, the heating power supply PWM signal is set to 0, and the heating is turned off.

[0042] S3: If the average value is within a preset second threshold range, a sampling temperature corresponding to the average value is obtained according to the average value as the current sampling temperature.

[0043] In this embodiment, the preset second threshold range is between 160 and 3920. If the average value is between 160 and 3920, the temperature sensor is set to a normal state, and the sampling temperature corresponding to the average value is obtained according to the average value as the current sampling temperature.

[0044] In the above step S1, the AD value of the data fed back by the temperature sensor is sampled 10 times within one second, and the sampled data is calculated to obtain an average value. In step S3, if the average value is within the preset second threshold range, the sampling temperature corresponding to the average value is obtained as the current sampling temperature according to the average value. If the elapsed time is less than one second, the above steps are continued until the above steps have been counted for a full second.

[0045] S4: Set the target temperature to compare with the current sampling temperature, substitute the target temperature and the current sampling temperature into the PID algorithm, calculate and obtain the PID output value, and calculate and obtain the PWM duty cycle value for controlling heating according to the PID output value.

[0046] The steps of the PID algorithm are: turn on the heating; execute the PID algorithm; output the power supply PWM duty cycle through the output value of the PID algorithm; convert the power supply switch state according to the PWM duty cycle; the power supply switch state controls the heating of the heating wire; the temperature sensor feeds back the temperature of the heating wire; feeds back to execute the PID algorithm and loop the steps.

[0047] S5: Through the high-frequency PWM to low-frequency on-off algorithm, the signal corresponding to the PWM duty cycle value is converted into a low-frequency on-off signal to control the power supply of the heating wire. If the PWM duty cycle value is higher than the preset PWM upper limit value, the heating module accelerates heating. In this embodiment, the preset PWM upper limit value is set to 60.

[0048] S6: Through the high-frequency PWM to low-frequency on-off algorithm, the signal corresponding to the PWM duty cycle value is converted into a low-frequency on-off signal to control the power supply of the heating wire. If the PWM duty cycle value is lower than the preset PWM lower limit value, the heating module turns off the heating. In this embodiment, the preset PWM lower limit value is set to 40.

[0049] If the PWM duty cycle value is between the preset PWM upper limit value and the preset PWM lower limit value, the power supply output state of the heating module remains unchanged, and a one-second time is set to clear all values ​​and re-assign values. Then return to step S1 to sample the data fed back by the temperature sensor multiple times within a preset time interval, calculate the sampled data to obtain an average value, and loop through subsequent steps.

[0050] The advantages of the present invention are as follows: by sampling the data fed back by the temperature sensor multiple times within one second, and calculating the average value of the sampled data; judging whether the average state of the sampled data is normal; if the average state is normal, obtaining the corresponding current sampling temperature according to the average value; setting the target temperature to compare with the current sampling temperature, and substituting the target temperature and the current sampling temperature into the PID algorithm, calculating and obtaining the PID output value; calculating and obtaining the PWM duty cycle value for controlling heating according to the PID output value; and converting the signal corresponding to the PWM duty cycle value into a low-frequency on-off signal to control the power supply of the heating wire through the high-frequency PWM to low-frequency on-off algorithm. The amount of data for adjusting the parameters in the seat heating calibration process is reduced, and pulse radiation generated by high-frequency PWM is avoided while achieving adaptive temperature regulation.

[0051] Embodiment 2:

[0052] like Figure 1 As shown, a car seat heating control system, based on a car seat heating control method described in embodiment 1, comprises:

[0053] The temperature sensing module is used to collect the temperature of the heating module in the seat and convert the collected analog signal into a digital signal to feedback data;

[0054] A calculation module is used to sample the data fed back by the temperature sensor multiple times within a preset time interval, and calculate the sampled data to obtain an average value;

[0055] An average value determination module is used to determine the calculated average value, and if the average value is within a preset first threshold range, the heating module is turned off; if the average value is within a preset second threshold range, a sampling temperature corresponding to the average value is obtained according to the average value as the current sampling temperature;

[0056] PID algorithm module, sets the target temperature to compare with the current sampling temperature, substitutes the target temperature and the current sampling temperature into the PID algorithm to calculate and obtain the PID output value, and calculates the corresponding power supply PWM duty cycle value through the PID output value;

[0057] The high-frequency PWM to low-frequency on-off algorithm module is used to convert the PWM duty cycle value into a low-frequency on-off signal to control the power supply of the heating wire. If the PWM duty cycle value is higher than the preset PWM upper limit value, the heating module accelerates the heating; if the PWM duty cycle value is lower than the preset PWM lower limit value, the heating module turns off the heating.

[0058] Preferably, the calculation module further comprises: judging whether the average value state of the sampled data is normal.

[0059] By changing some structures in the embodiment, the new embodiment can obtain the same technical functions and effects. Advantages of the implementation of the present invention: by sampling the data fed back by the temperature sensor multiple times within one second, and calculating the average value of the sampled data; judging whether the average state of the sampled data is normal; if the average state is normal, obtaining the corresponding current sampling temperature according to the average value; setting the target temperature to compare with the current sampling temperature, and substituting the target temperature and the current sampling temperature into the PID algorithm, calculating and obtaining the PID output value; calculating and obtaining the PWM duty cycle value for controlling heating according to the PID output value; through the high-frequency PWM to low-frequency on-off algorithm, the signal corresponding to the PWM duty cycle value is converted into a low-frequency on-off signal to control the power supply of the heating wire. The amount of data for adjusting the parameters in the seat heating calibration process is reduced, and pulse radiation generated by high-frequency PWM is avoided while achieving adaptive temperature regulation.

[0060] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for controlling heating of a car seat, wherein a heating module and a temperature sensor are arranged in the car seat, and the temperature sensor is used to collect the temperature of the heating module and feed back data, characterized in that: The following steps are involved: The data fed back by the temperature sensor are sampled multiple times within a preset time interval, and the sampled data are calculated to obtain an average value; If the average value is within a preset first threshold range, turning off the heating module; If the average value is within the preset second threshold range, the sampling temperature corresponding to the average value is obtained according to the average value as the current sampling temperature; The target temperature is set to be compared with the current sampling temperature, and the target temperature and the current sampling temperature are substituted into the PID algorithm to calculate and obtain the PID output value, and the PWM duty cycle value for controlling the heating is calculated and obtained according to the PID output value, which is specifically through a high-frequency PWM to low-frequency on-off algorithm, and the signal corresponding to the PWM duty cycle value is converted into a low-frequency on-off signal to control the power supply of the heating module; If the PWM duty cycle value is higher than the preset PWM upper limit value, the heating module accelerates heating; If the PWM duty cycle value is lower than the preset PWM lower limit value, the heating module turns off the heating.

2. A method for controlling automobile seat heating according to claim 1, characterized in that: The preset first threshold range is less than 160 or greater than 3920; the preset second threshold range is between 160 and 3920.

3. A method for controlling automobile seat heating according to claim 2, characterized in that: If the average value is less than 160 or greater than 3920, the temperature sensor is set to short circuit or open circuit state, and the heating power supply PWM signal is set to 0, and the heating is turned off; if the average value is between 160 and 3920, the temperature sensor is set to normal state and proceed to the next step.

4. The method for controlling automobile seat heating according to claim 1, characterized in that: The data fed back by the temperature sensor is sampled multiple times within a preset time interval, and the sampled data is calculated to obtain an average value. If the average value is within a preset second threshold range, the sampling temperature corresponding to the average value is obtained as the current sampling temperature according to the average value. If the elapsed time does not meet the preset time, the above steps are continued until the above steps have passed the complete preset time.

5. The method for controlling automobile seat heating according to claim 1, characterized in that: The preset PWM upper limit value is set to 60; the preset PWM lower limit value is set to 40.

6. The method for controlling automobile seat heating according to claim 1, characterized in that: If the PWM duty cycle value is between the preset PWM upper limit value and the preset PWM lower limit value, the power supply output state of the heating module remains unchanged, and a certain time is set to clear all values ​​and re-assign them.

7. The method for controlling automobile seat heating according to claim 6, characterized in that: After setting a certain time to clear all values ​​and re-assign values, return to the step of sampling the data fed back by the temperature sensor multiple times within a preset time interval, calculate the sampled data to obtain an average value, and loop through subsequent steps.

8. The method for controlling automobile seat heating according to claim 1, characterized in that: The steps of the PID algorithm are: turn on the heating; execute the PID algorithm; output the power supply PWM duty cycle through the output value of the PID algorithm; convert the power supply switch state according to the PWM duty cycle; the power supply switch state controls the heating of the heating wire; the temperature sensor feeds back the temperature of the heating wire; Feedback is then performed to execute the PID algorithm and the steps are looped.

9. A car seat heating control system, characterized in that: include: A temperature sensing module is used to collect the temperature of the heating module in the seat; A calculation module is used to sample the data fed back by the temperature sensor multiple times within a preset time interval, and calculate the sampled data to obtain an average value; an average value determination module, used to determine the calculated average value, and if the average value is within a preset first threshold range, shut down the heating module; If the average value is within the preset second threshold range, the sampling temperature corresponding to the average value is obtained according to the average value as the current sampling temperature; PID algorithm module, sets the target temperature to compare with the current sampling temperature, substitutes the target temperature and the current sampling temperature into the PID algorithm to calculate and obtain the PID output value, and calculates the corresponding power supply PWM duty cycle value through the PID output value; The high-frequency PWM to low-frequency on-off algorithm module is used to convert the PWM duty cycle value into a low-frequency on-off signal to control the power supply of the heating wire. If the PWM duty cycle value is higher than the preset PWM upper limit value, the heating module accelerates the heating; if the PWM duty cycle value is lower than the preset PWM lower limit value, the heating module turns off the heating.

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