阅读说明：本技术 一种汽车座椅通风系统的pwm信号传输方法及其系统 (PWM signal transmission method and system of automobile seat ventilation system ) 是由 辛东波 任燕汶 梅晨龙 于 2019-08-19 设计创作，主要内容包括：本申请涉及一种汽车座椅通风系统的PWM信号传输方法及其系统,通过对PWM信号的预通讯位及通讯校准位进行信号过滤,且同时通过功能定义数据来定义不同转速的档位；其有益效果在于：解决PWM信号干扰畸形导致的转速不稳定的问题；风扇接收到标准的信号后,执行预设的目标转速；接收到被干扰的畸形信号,不响应畸形信号,保持原有的转速档位,起到信号过滤的目的。(The application relates to a PWM signal transmission method and a system thereof of a ventilation system of an automobile seat, which carry out signal filtration by pre-communication position and communication calibration position of a PWM signal and define gears with different rotating speeds by function definition data; the beneficial effects are that: the problem of unstable rotating speed caused by PWM signal interference deformity is solved; after the fan receives the standard signal, executing a preset target rotating speed; the disturbed malformed signal is received, the malformed signal is not responded, the original rotating speed gear is kept, and the purpose of signal filtering is achieved.)

1. A PWM signal transmission method of a ventilation system of a vehicle seat, which is applied to a device controlled by a PWM signal, includes:

monitoring a PWM signal line and acquiring a current PWM signal;

checking the current PWM signal and a pre-checking signal;

acquiring a check result of a current PWM signal and a pre-check signal, and monitoring a PWM signal line if the check result passes, so as to acquire an effective signal; otherwise abandon the present PWM signal, monitor the PWM signal line again;

and processing the effective signal.

2. The PWM signal transmission method of an automobile seat ventilation system according to claim 1, wherein the monitoring of the PWM signal line and the acquisition of the current PWM signal; the method comprises the following steps:

the current value of the PWM signal line is read and written into a first register within the device while a timer within the device is counting.

3. The PWM signal transmission method of a vehicle seat ventilation system according to claim 2, wherein the pre-verification signal is stored in the second register.

4. The PWM signal transmission method of a ventilation system for a vehicle seat according to claim 3, wherein the comparing the current PWM signal with a pre-calibration signal comprises:

when the timer reaches a preset time value or the data bit of the current PWM signal reaches a preset digit, comparing the current PWM signal of the first register with the pre-check signal of the second register;

if the first register is equal to the second register, clearing the first register, resetting the timer, and continuously monitoring the PWM signal line to acquire valid data;

otherwise, clearing the first register, resetting the timer, continuing monitoring the PWM signal line, and reacquiring the current PWM signal.

5. The PWM signal transmission method of a car seat ventilation system according to claim 1, wherein the pre-verification signal comprises:

pre-communication position, to carry out the preparation work before communication;

and (4) carrying out signal calibration to remove the accumulated error of the pre-communication bit.

6. The PWM signal transmission method of an automobile seat ventilation system according to claim 5, wherein the pre-communication bit is a two-bit low-level signal.

7. The PWM signal transmission method of an automobile seat ventilation system according to claim 5, wherein the communication calibration level is a three-level signal including a high level, a low level and a high level in sequence.

8. The PWM signal transmission method of a vehicle seat ventilation system according to claim 2, wherein the obtaining of the valid signal comprises:

and reading continuous five-bit data of the PWM signal line, and storing the continuous five-bit data into the first register, wherein a timer in the device is used for timing.

9. The PWM signal transmission method of a car seat ventilation system according to claim 8, wherein the processing the valid signal comprises:

performing table look-up comparison on the effective signal and a preset data set stored in a third register;

if the effective signals are matched with the data in the preset data set, corresponding operation is carried out;

otherwise, discarding the effective signal and resetting the timer, monitoring the PWM signal line again, and acquiring the current PWM signal.

10. The PWM signal transmission method of a ventilation system for a vehicle seat according to claim 9, wherein the number of the function definition data of the preset data set is any integer value between 1 ~ 32.

11. The PWM signal transmission method of a car seat ventilation system according to claim 9, wherein if the data of the valid signal in the preset data set matches, the corresponding operation is performed; the method comprises the following steps:

and the effective signal is matched with the function definition data of the preset data set, and corresponding rotating speed is output according to the function definition data.

12. A system comprising a processing module performing PWM signal transmission by operating the PWM signal transmission method of the car seat ventilation system according to any one of claims 1 to 11.

Technical Field

The application relates to the technical field of driving assistance, in particular to a PWM signal transmission method and system of an automobile seat ventilation system.

Background

With the rapid development of economic society, automobiles now enter common people, and now the automobiles are not only a transportation tool for the common people, so people pay more and more attention to the comfort and functionality of the automobiles when taking the automobiles. The problem of traffic jam generally exists in modern cities, so that people take a bus for a long time, and the temperature between the body and the seat is higher. According to actual experience, in the weather with the temperature of more than 25 ℃, the passenger continuously takes the car for 40 minutes, the seat part and the back part of the body obviously feel uncomfortable, and then the road anger emotions such as dysphoria and anxiety are caused, so that a system is urgently needed to reduce the temperature of the seat so as to relieve the fatigue of passengers in the car and improve the riding comfort.

Electromagnetic environments of automobile products are complex, the existing PWM speed regulation method is easy to interfere in the complex electromagnetic environments and cannot stably operate, and particularly in harsh EMC test, PWM signals are likely to be influenced by interference sources in the test process, so that the PWM signals are malformed, a fan cannot stably operate, and finally the test fails.

Disclosure of Invention

In order to solve the technical problems, the application provides a PWM signal transmission method and system of an automobile seat ventilation system, and aims to solve the problem of unstable fan rotating speed caused by PWM signal interference deformity.

The application provides a PWM signal transmission method of an automobile seat ventilation system, which is applied to a device controlled by a PWM signal and comprises the following steps:

monitoring a PWM signal line and acquiring a current PWM signal;

checking the current PWM signal and a pre-checking signal;

acquiring a check result of a current PWM signal and a pre-check signal, and monitoring a PWM signal line if the check result passes, so as to acquire an effective signal; otherwise abandon the present PWM signal, monitor the PWM signal line again;

and processing the effective signal.

Optionally, the monitoring a PWM signal line and obtaining a current PWM signal; the method comprises the following steps:

the current value of the PWM signal line is read and written into a first register within the device while a timer within the device is counting.

Optionally, the pre-check signal is stored in a second register.

Optionally, the comparing the current PWM signal with a pre-calibration signal includes:

when the timer times to reach a preset time value or the data bit of the current PWM signal reaches a preset digit, comparing the current PWM signal of the first register with the pre-check signal of the second register;

if the first register is equal to the second register, clearing the first register, resetting the timer, and continuously monitoring the PWM signal line to acquire valid data;

otherwise, clearing the first register, resetting the timer, continuing monitoring the PWM signal line, and reacquiring the current PWM signal.

Optionally, the pre-verification signal comprises:

pre-communication position, to carry out the preparation work before communication;

and (4) carrying out signal calibration to remove the accumulated error of the pre-communication bit.

Optionally, the pre-communication bit is a two-bit low-level signal.

Optionally, the communication calibration bit is a three-bit level signal including a high level, a low level, and a high level in sequence.

Optionally, the acquiring a valid signal includes:

and reading continuous five-bit data of the PWM signal line and storing the continuous five-bit data into the first register.

Optionally, the processing the valid signal includes:

performing table look-up comparison on the effective signal and a preset data set stored in a third register;

if the effective signals are matched with the data in the preset data set, corresponding operation is carried out;

otherwise, discarding the effective signal and resetting the timer, monitoring the PWM signal line again, and acquiring the current PWM signal.

Optionally, the function of the preset data set defines the data quantity to be any integer value between 1 ~ 32.

Optionally, the rotation speed interval of the plurality of functional predefined data sequentially output correspondingly is (N + 3)%.

Optionally, if the valid signal matches with the data in the preset data set, performing a corresponding operation; the method comprises the following steps:

and the effective signal is matched with the function definition data of the preset data set, and corresponding rotating speed is output according to the function definition data.

In addition, the application also provides a system which comprises a processing module, wherein the processing module operates the PWM signal transmission method of the automobile seat ventilation system to perform PWM signal transmission.

According to the PWM signal transmission method and the system of the automobile seat ventilation system, signal filtering is carried out on the pre-communication position and the communication calibration position of the PWM signal, and meanwhile gears with different rotating speeds are defined through function definition data; the beneficial effects are that: the problem of unstable rotating speed caused by PWM signal interference deformity is solved; after the fan receives the standard signal, executing a preset target rotating speed; the disturbed malformed signal is received, the malformed signal is not responded, the original rotating speed gear is kept, and the purpose of signal filtering is achieved.

Drawings

Fig. 1 is a schematic diagram of a PWM signal transmission method according to an embodiment of the present application;

FIG. 2 is a schematic diagram illustrating a comparison between a current PWM signal and a pre-calibration signal according to an embodiment of the present application;

fig. 3 is a schematic diagram illustrating processing of the effective signal according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a default data set according to an embodiment of the present application;

fig. 5 is a current PWM signal and valid data bitmap according to an embodiment of the present application.

Detailed Description

The following detailed description of the preferred embodiments of the present application, taken in conjunction with the accompanying drawings, will make the advantages and features of the present application more readily appreciated by those skilled in the art, and thus will more clearly define the scope of the invention.

The method and the device aim to solve the problem that the fan rotating speed is unstable due to PWM signal interference deformity.

In an embodiment as shown in fig. 1, the present application provides a PWM signal transmission method of a car seat ventilation system, applied to a device controlled by a PWM signal, including:

monitoring a PWM signal line and acquiring a current PWM signal 100;

in this step, the device controlled by the PWM signal, that is, the device controlled by the PWM signal is received, and the device may be any device capable of being controlled by the PWM signal, such as a fan, an air conditioner, and the like; the device for emitting the PWM signal line may be a vehicle controller, which continuously outputs a corresponding PWM signal to the outside by continuously recognizing a corresponding temperature by receiving a temperature signal of a vehicle or a contact portion of a vehicle seat with a human body; the device is connected with equipment sending out PWM signal lines through signal lines, power lines and ground lines. The step of continuously monitoring the signal wire transmitted by the equipment for transmitting the PWM signal wire to transmit the PWM signal to the device controlled by the PWM signal; after the device acquires the current PWM signal, the current PWM signal is stored in a first register.

200, checking the current PWM signal and the pre-checking signal;

in this step, the pre-calibration signal is stored in the second memory, which includes a pre-communication bit for performing a preparation operation before communication and a communication calibration bit for performing signal calibration to remove an accumulated error of the pre-communication bit. The device continuously acquires each digit of the current PWM signal by monitoring the PWM signal line and performs timing; the PWM signal is timed to reach the preset time, namely the current PWM signal is compared with the pre-check signal. The process comprises the following steps: when the timer reaches a preset time value, comparing the current PWM signal of the first register with the pre-check signal of the second register; if the first register is equal to the second register, emptying the first register, and continuously monitoring the PWM signal line to acquire valid data; otherwise, emptying the first register, continuously monitoring the PWM signal line, and reacquiring the current PWM signal.

300, obtaining a checking result of the current PWM signal and the pre-checking signal, and monitoring a PWM signal line if the checking result passes, so as to obtain an effective signal; otherwise abandon the present PWM signal, monitor the PWM signal line again;

in the step, when the timer reaches a preset time value, comparing the current PWM signal of the first register with the pre-check signal of the second register; if the first register is equal to the second register, emptying the first register, and continuously monitoring the PWM signal line to acquire valid data; otherwise, emptying the first register, continuously monitoring the PWM signal line, and reacquiring the current PWM signal.

And 400, processing the effective signal.

In the step, processing the effective signal comprises comparing the effective signal with a preset data set stored in a third register by table look-up; if the effective signals are matched with the data in the preset data set, corresponding operation is carried out; otherwise, discarding the effective signal, monitoring the PWM signal line again, and obtaining the current PWM signal. If the effective signals are matched with the data in the preset data set, corresponding operation is carried out, namely when the effective signals fall into the preset data set, the effective signals inquire corresponding function definition data corresponding to the preset data set, and corresponding output rotating speed is activated according to the corresponding function definition data so as to achieve the purpose of adjusting the rotating speed of the fan.

In the embodiment, the pre-communication bit and the communication calibration bit of the PWM signal are subjected to signal filtering, and meanwhile, the gears with different rotating speeds are defined through function definition data; the problem of unstable rotating speed caused by PWM signal interference deformity is solved; after the fan receives the standard signal, executing a preset target rotating speed; the disturbed malformed signal is received, the malformed signal is not responded, the original rotating speed gear is kept, and the purpose of signal filtering is achieved.

In some embodiments, a PWM signal line is monitored and a current PWM signal is obtained; the method comprises the following steps:

the current value of the PWM signal line is read and written into a first register within the device while a timer within the device is counting.

In this embodiment, the current value of the PWM signal line is read, and the data value of the current PWM signal is obtained. The PWM signal sent out from the equipment used for sending the PWM signal line is a high level or low level signal, and the device converts the received level signal into a digital signal and then transmits the digital signal into the first register. The current PWM signal comprises five-bit data bits which are respectively two-bit pre-communication bits and three-bit communication calibration bits; when reading the first pre-communication bit, a first timer arranged in the device starts timing; and after the five-bit data is read, the timer finishes timing.

In some embodiments, the pre-verify signal is stored in a second register; the pre-calibration signal can be an artificially defined standard signal and is used for matching the current PWM signal; the pre-check signal is stored in the second register and does not change in the whole working process of the device; the value and the number of digits of the pre-check signal can be adjusted before the device works according to actual working conditions.

In the embodiment shown in fig. 2, comparing the current PWM signal with the pre-calibration signal includes:

when the timer times to reach a preset time value or the data bit of the current PWM signal reaches a preset bit number, comparing the current PWM signal of the first register with the pre-verification signal of the second register;

in the step, after the current PWM step is obtained, the current PWM signal of the first sender is compared with the pre-check signal of the second register; the time for completing the current PWM step can be timed by a timer to reach a preset time value or the data bit of the current PWM signal reaches a preset digit for judgment; the preset time value and the preset digit can be defined manually, and the numerical values can be stored in a fourth register of the device; in this embodiment, the time for completing the current PWM step is determined by the timer reaching a preset time value.

210, if the first register is equal to the second register, clearing the first register, resetting the timer, and continuing to monitor the PWM signal line to acquire valid data;

220, in this step, when the current PWM signal of the first register is equal to the pre-check signal of the second register, it indicates that the current PWM signal is not interfered, i.e. the corresponding valid signal can be read from the PWM signal line, and the fan speed is adjusted according to the valid signal. The acquired valid signal is stored in a first register, and a timer of the first register counts time.

And 230, otherwise, clearing the first register, resetting the timer, continuing monitoring the PWM signal line, and reacquiring the current PWM signal.

In the step, the first register is emptied, and after the timer is reset, the PWM signal wire is monitored continuously, and the current PWM signal is obtained again; the current PWM signal is stored in the first register and clocked.

In the embodiment, the pre-communication bit and the communication calibration bit of the PWM signal are subjected to signal filtering; the problem of unstable rotating speed caused by PWM signal interference deformity is solved; after the fan receives the standard signal, executing a preset target rotating speed; the disturbed malformed signal is received, the malformed signal is not responded, the original rotating speed gear is kept, and the purpose of signal filtering is achieved.

In some embodiments, the pre-calibration signal comprises:

pre-communication position, to carry out the preparation work before communication; in this embodiment, the pre-communication bit is a two-bit low-level signal; the first two bits are at a level of 00 and each bit has a duration of 40ms, which is set to perform a preliminary operation before communication. After the controller sends out a low level signal for continuous 80ms, the fan should be able to detect the low level signal for continuous 80ms under normal conditions, and then needs to receive data; if the strong interference causes the 80ms low signal to be inverted in the middle during the period, which indicates that the strong interference may cause signal distortion, the fan receiving end should abandon the communication and continue to wait for the next 80ms signal.

And (4) carrying out signal calibration to remove the accumulated error of the pre-communication bit. The pre-communication bit is a two-bit low-level signal; in this embodiment, the communication calibration level is a three-level signal sequentially including a high level, a low level, and a high level; the middle three bits are communication calibration bits, the purpose of the communication calibration bits is to remove accumulated errors caused by pre-communication, and when a fixed value of 101 is received, the next received data is a function definition bit, and the time is designed to be 7ms/3ms/7ms, so that the inaccuracy of the read signal caused by periodic interference is prevented; during this period, if the received signal is not 101, the communication is directly abandoned and the next continuous low-level signal of 80ms is continuously waited.

In some embodiments, acquiring a valid signal comprises:

reading continuous five-bit data of the PWM signal line and storing the continuous five-bit data into a first register;

in this embodiment, the five consecutive bits of data of the PWM signal line are the last five bits of data of the current PWM signal, and when the current PWM signal is consistent with the pre-verification signal, the data of the first register is cleared, and the five consecutive bits of data of the current PWM signal are stored in the first register, and the timing is started. The next 5 bits of data are function definition bits, which can expand 32 function definitions at most, and can use 32 different functions in similar items; the fan has limited gears, only 18 gears are used for standby, and the method is shown in FIG. 4; in actual projects, according to different designs and noise requirements of an air duct, a proper gear with a high gear, a proper gear with a medium gear and a proper gear with a low gear can be selected for use; the gear output rotating speed interval is (N + 3)%.

In the embodiment shown in fig. 3, the processing of the valid signal includes:

410, comparing the effective signal with a preset data set stored in a third register by table lookup;

420, if the valid signals are matched with the data in the preset data set, performing corresponding operation;

430, otherwise, the valid signal is discarded and the timer is reset, the PWM signal line is re-monitored, and the current PWM signal is acquired.

In the embodiment, the device is pre-stored with a preset data set, the preset data set is a five-bit binary data, the number of function definition data of the preset data set is any integer value between 1 ~ 32, in the embodiment, the number of the function definition data is 18, each function definition data corresponds to different output rotating speeds, the rotating speed interval of the multiple function definition data which are sequentially output correspondingly is (N + 3)%, that is, the first function definition data "00000" corresponds to 4% of the output rotating speed, the valid signal is compared with the preset data, that is, the five-bit valid signal is compared with the 18 function definition data, and if the valid signal is matched with one function definition data, the activation device outputs the corresponding rotating speed.

In one implementation of the above embodiment, the function of the preset data set may define the data amount to be any integer value between 1 ~ 32.

In one implementation of the foregoing embodiment, the rotation speed interval of the plurality of function predefined data sequentially outputted corresponds to (N + 3)%.

In an implementation of the foregoing embodiment, if the valid signals match with the data in the preset data set, a corresponding operation is performed; the method comprises the following steps:

the effective signal is matched with the function definition data of the preset data set, and corresponding rotating speed is output according to the function definition data.

In the embodiment shown in fig. 2, the present application further provides a system including a processing module performing PWM signal transmission by operating the PWM signal transmission method of the car seat ventilation system as described above.

In this embodiment, the system can transmit the PWM signal by the PWM signal transmission method of the car seat ventilation system, the system is stored in the device controlled by the PWM signal, that is, the device controlled by receiving the PWM signal, and the device can be any device capable of being controlled by the PWM signal, such as a fan, an air conditioner, etc.; the device for emitting the PWM signal line may be a vehicle controller, which continuously outputs a corresponding PWM signal to the outside by continuously recognizing a corresponding temperature by receiving a temperature signal of a vehicle or a contact portion of a vehicle seat with a human body; the device is connected with equipment sending out PWM signal lines through signal lines, power lines and ground lines. Performing signal filtering on a pre-communication bit and a communication calibration bit of a PWM signal, and defining gears with different rotating speeds through function definition data; the problem of unstable rotating speed caused by PWM signal interference deformity is solved; after the fan receives the standard signal, executing a preset target rotating speed; the disturbed malformed signal is received, the malformed signal is not responded, the original rotating speed gear is kept, and the purpose of signal filtering is achieved.

In some embodiments, referring to fig. 5, the PWM signal transmission method can be implemented by the following steps:

reading the current value of the signal line, and waiting for the next rising edge when reading 70m which is a low level; the step is used for detecting whether the current electromagnetic environment has enough interference energy to interfere normal transmission of signals; at this stage, if the continuous low signal is interrupted, the read value is discarded, and the signal line is monitored continuously for the next set of pre-communication bits:

when the first rising edge is detected, resetting the timing flag bit, timing for 3.5mS at the same time, and starting to read the address check bit; reading effective data, if the read data is inconsistent with the defined data in the process, giving up the read data, continuously executing the existing function, monitoring a signal line and waiting for the next pre-communication bit; if the correct numerical value is read, executing the corresponding function;

when 3.5mS is reached, reading the current value of the PWM signal line, writing the current value into a first data register, and simultaneously continuing timing; wherein, the function of this step is to read the first data of calibration bit;

when 3.5+1.5mS is reached, reading the current value of the PWM signal wire, writing the current value into a first data register, and simultaneously continuing timing; wherein the step is used for reading the second bit data of the calibration bit;

when 1.5+3.5mS is reached, reading the current value of the PWM signal wire, writing the current value into a first data register, and simultaneously continuing timing; wherein, the function of this step is to read the third data of calibration bit;

comparing the difference between the second data register and the first data register, emptying the first data register if the difference is not equal, re-reading the current value of the signal line, and waiting for the next rising edge when reading 70m which is a low level; if the data are equal, clearing the first register of the data, and continuing the next step; the step is used for comparing whether the three data of the calibration bit are the same as the 3 predefined data or not, if so, continuing to perform the next step, and if not, abandoning the current data and monitoring a signal line;

when the falling edge is read, resetting the timer and starting timing; starting to read the data bits; wherein, the function of this step is to read the first bit data of function definition bit;

when the current value reaches 1.5mS, reading the current value of the PWM signal line, writing the current value into a first data register, and simultaneously continuing timing; wherein the step is used for reading the second bit data of the function definition bit;

when the time reaches 1.5ms +2.5ms, reading the current value of the signal line, writing the current value into a first data register, and simultaneously continuing timing; wherein the step is used for reading the second bit data of the function definition bit;

when reaching 2.5ms +2.5ms, reading the current value of the signal line, writing the current value into a first data register, and simultaneously continuing timing; wherein, the function of this step is to read the third bit data of function definition bit;

when reaching 2.5ms +2.5ms, reading the current value of the signal line, writing the current value into a first data register, and simultaneously continuing timing; wherein, the function of this step is to read the fourth bit data of the function definition bit;

when reaching 2.5ms +2.5ms, reading the current value of the signal line and writing the current value into a first data register; wherein, the function of this step is to read the fifth bit data of function definition bit;

comparing the value of the first data register with a preset value, and if the value is equal to a certain preset value, executing a function corresponding to the preset value; if any value is not equal to the preset value, reading the current value of the signal line again, and waiting for the next rising edge when reading 70m which is low level; the step is used for comparing the read data of the function definition bit with preset data and confirming the function to be executed next.

In the embodiments described above, the PWM signal transmission method of the car seat ventilation system includes a system and belongs to the same concept, any method step provided in the PWM signal transmission method embodiments may be operated on the device, the specific implementation process is described in the method embodiments in detail, and any optional embodiment may be adopted in combination to form the application, and details are not repeated herein.

The embodiments of the present application have been described in detail with reference to the drawings, but the present application is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present application within the knowledge of those skilled in the art.