Tail gas heater control system and control method

Abstract

The tail gas heater control system comprises a main controller, a driving power module, a power supply module, a communication module, an input and output module, a driving module and a serial universal interface module, the power supply module, the communication module, the input and output module, the driving module and the serial universal interface module are integrated in the main controller, and the power supply module is connected with an external power supply and used for supplying power to all the modules. The communication module is in communication connection with a vehicle body controller and can transmit signals of the vehicle body controller to the main controller for processing, the driving module and the serial universal interface module are both connected with the driving power module, the driving power module is connected with the tail gas heater, and the tail gas heater is connected with the main controller. The driving module and the serial universal interface module send control signals to the driving power module based on signals of the main controller, and the driving power module provides current to the tail gas heater based on the signals so as to control the state of the tail gas heater.

Description

Technical Field

[0001] The invention relates to the technical field of automobile exhaust treatment, and in particular to an exhaust gas heater control system and a control method. Background Art

[0002] Most of the old traditional exhaust treatment technologies use the working principle of a three-way catalytic converter through redox reaction, fuel injection combustion or the use of urea reaction to convert carbon monoxide, hydrocarbons, nitrogen oxides (NOX) and particulate matter (PM) in the exhaust gas into harmless substances such as carbon dioxide (CO2), water (H2O), nitrogen (N2) and discharged through the tailpipe.

[0003] However, the emission standard of National VI is much higher than that of National V. The WLTP (Light Vehicle Test Procedure) cycle of National 6A is completely different. It has various transition conditions, and the speed is constantly changing over time. The test standard is more in line with real driving conditions. There are stricter requirements for particulate matter and exhaust emissions. The particulate matter filter (DPF) in the exhaust treatment system of fuel vehicles is very likely to cause blockage due to long-term accumulation of particulate matter, which will increase the content of harmful substances in the exhaust gas and fail to meet the emission standards because of untimely regeneration and discharge.

[0004] The new treatment technology takes into full account the ignition temperature of the catalyst during cold start and the insufficient power during start and idling to treat harmful substances in the exhaust gas. It proposes to perform high-temperature secondary combustion treatment on the particulate matter in the exhaust gas before the exhaust gas is discharged by means of electronically controlled heating at the front end of the DPF particulate filter in the exhaust emission system of fuel vehicles, so that the vehicle's emissions meet national standards.

[0005] The existing exhaust gas heater has the problem of low heater temperature when the vehicle engine and battery power are insufficient during vehicle startup and idling. Summary of the invention

[0006] In view of the above-mentioned technical problems existing in the existing exhaust gas heaters, the purpose of the present invention is to provide an exhaust gas heater control system and control method. By innovating the exhaust gas heater system, the vehicle speed signal and the particulate filter working status signal are obtained through communication with the vehicle body controller, and the parallel MOSFET is driven by PWM wave at idling and starting to provide a large current to the heating device.

[0007] In order to achieve the above-mentioned purpose, the exhaust gas heater control system provided by the present invention includes a main controller, a driving power module and a power module integrated on the main controller, a communication module, an input and output module, a driving module, and a serial universal interface module. The power module is connected to an external power supply to power all modules, and the power module is connected to a start level circuit to collect the start level.

[0008] The communication module is connected to the vehicle body controller for communication, and the communication between the main controller and the vehicle body controller is realized through the communication module. The input and output module is used to detect the working state of the exhaust gas heater; the drive module and the serial universal interface module are both connected to the drive power module, and the drive power module is connected to the exhaust gas heater. The serial universal interface module is used for communicating with the main controller, receiving instructions from the main controller, controlling the drive module and feeding back the state of the drive module;

[0009] The driving module is used to send a driving level to the driving power module;

[0010] The main controller can obtain the vehicle speed signal and the particulate trap working state signal collected by the body controller through the communication module, and the main controller also monitors the working state of the power module, the communication module, and the exhaust gas heater. The main controller can process the vehicle speed signal and the particulate trap working state signal collected by the body controller and the working state of the power module and the communication module to form an exhaust gas heater opening or closing signal and send it to the driving power module through the driving module and the serial universal interface module, and the driving power module thereby controls the exhaust gas heater to open or close;

[0011] Based on the vehicle speed signal collected by the main controller through the communication module, and when the starting level collected by the power module is lower than the set voltage, the main controller controls the drive module through the serial universal interface module to use PWM waves to drive the power module. The drive power module drives the parallel MOSFET based on the signal to provide a large current to the exhaust heater. The main controller controls the drive module through the serial universal interface module to use PWM waves to change the duty cycle based on the change of the vehicle speed signal to control the output of the exhaust heater.

[0012] Furthermore, the exhaust heater control system also includes a sensor module, which is placed in the particulate trap. When the sensor module detects that carbon monoxide and hydrocarbons exceed the standard, it sends an "EHC heater state = enable" signal to the main controller through the communication module.

[0013] Furthermore, the main controller is an MCU.

[0014] Furthermore, a low voltage drop linear regulator is connected between the power module and the external power supply.

[0015] Furthermore, the communication module is connected to a control area network transceiver, and the CAN network communication between the communication module and the vehicle body controller is realized through the control area network transceiver.

[0016] Furthermore, the external interface of the input-output module is connected to the exhaust heater status through a level indicator, and the drive module is controlled to shut down and start through a switch button. The high and low levels are given to the main controller, which is at a high level when working, and the main control shuts down the output when it is at a low level;

[0017] The driving power module is internally provided with two high-side drivers, which increase the driving current of the driving level of the driving module and provide impedance matching for the two high-side drivers, thereby driving the parallel MOSFET to provide a large current to the heating device.

[0018] Furthermore, the exhaust gas heater control system further includes a timer, which is connected to the main controller respectively, and the timer is internally configured with a heater on timing and a heater off timing. When the main controller generates a signal to turn on the exhaust gas heater, the main controller controls the timer to start, and the heater on timing and the heater off timing in the timer are started simultaneously. After the heater on timing of the timer times out, the main controller sends a signal to turn on the exhaust gas heater.

[0019] When the heater shut-off timing inside the timer exceeds this time, the main controller generates a signal to shut down the exhaust gas heater.

[0020] In order to achieve the above object, the present invention provides a control method of an exhaust gas heater control system, which is used in any one of the above items, including:

[0021] S1: The main controller detects the exhaust gas heater through the input and output module, and the main controller monitors the working status of the communication module. When the main controller detects that the communication of the communication module is normal, it enters the next step. When the main controller detects that the communication of the communication module is abnormal, the main controller detects whether the switch button between the input and output module and the exhaust gas heater is triggered. When triggered, it can generate a signal to turn on the exhaust gas heater;

[0022] S2: When the main controller 100 detects that the communication of the communication module is normal in S1, the main controller determines whether the carbon monoxide and hydrocarbons detected by the sensor module are exceeding the standard. If the main controller receives that the carbon monoxide and hydrocarbons are exceeding the standard, it generates a signal to start the exhaust heater. If the main controller does not receive the exceeding standard signal, it proceeds to the next step;

[0023] S3: When the main controller does not receive the exceeding signal, the main controller makes a judgment based on whether it receives the regeneration state signal of the particulate trap sent by the body controller, and generates a signal to start the exhaust gas heater when the main controller receives that the particulate trap is in the regeneration state;

[0024] S4: When the main controller generates a signal to start the exhaust gas heater, the main controller controls the timer to start. When the heater start timing configured inside the timer times out, the main controller sends a signal to start the exhaust gas heater to control the start of the exhaust gas heater.

[0025] S5: When the exhaust gas heater is in the on state, the main controller realizes intelligent closing of the exhaust gas heater based on the internal program;

[0026] S6: When the exhaust heater starts to shut down, the drive module controls the load output according to the following timing. The duty cycle gradually increases from 100% to 0%, and decreases by 6.66% every 300 milliseconds, which takes about 4.5 seconds in total. If an opening command is encountered during the shutdown process, the duty cycle will immediately start to increase gradually from the current duty cycle, increasing by 6.66% every 300 milliseconds until it reaches 100%, and the exhaust heater adjusts its output according to the engine speed.

[0027] Furthermore, the specific process of the intelligent shutdown in S5 includes:

[0028] S5.1: The main controller detects the power supply status of the power module. When the main controller detects that the power supply of the power module is normal, the main controller proceeds to the next step. When the main controller detects that the power supply of the power module is abnormal, the main controller directly generates a signal to shut down the exhaust gas heater.

[0029] S5.2: When the main controller detects that the power supply of the power module is normal in S5.1, the main controller detects the communication status of the communication module. When the main controller detects that the communication of the communication module is normal, it proceeds to the next step. When the main controller detects that the communication of the communication module is abnormal, the main controller detects whether the switch button between the input and output module and the exhaust gas heater is triggered. When the switch button is triggered and closed, a signal to close the exhaust gas heater can be generated;

[0030] S5.3: When the main controller detects that the communication of the communication module is normal, the main controller determines the heater closing timing inside the timer. When the heater closing timing inside the timer times out, the main controller generates a signal to close the exhaust gas heater. If it does not time out, it proceeds to the next step.

[0031] S5.4: When the heater shut-off timing inside the timer has not timed out, the main controller makes a judgment based on whether it has received a regeneration status signal of the particulate trap sent by the body controller. When the main controller receives that the particulate trap is not in the required state and receives that the carbon monoxide and hydrocarbon content sent by the body controller are not exceeding the standard, the main controller can generate a signal to shut down the exhaust heater, otherwise it proceeds to the next step;

[0032] S5.5: The main controller detects the status of the exhaust gas heater through the input and output module. If the exhaust gas heater is in an abnormal state, the main controller can generate a signal to shut down the exhaust gas heater. If the exhaust gas heater is in a normal state, S5.1-S5.5 are repeated until the main controller generates a signal to shut down the exhaust gas heater.

[0033] Furthermore, the specific process of adjusting the output of the exhaust gas heater according to the engine speed in S6 includes:

[0034] When the exhaust heater output PWM reaches 100%, if the engine speed is lower than 1000 rpm, the duty cycle of the exhaust heater output will slowly decrease from 100% to 86.6%, decreasing by 6.66% every 300 milliseconds. When the engine speed recovers from less than 1000 rpm to above 1050 rpm and exceeds 1050 rpm for more than ten seconds, the duty cycle of the EHC output will slowly increase from 86.6% to 100%, increasing by 6.66% every 300 milliseconds.

[0035] The exhaust gas heater control system and control method provided by the present invention, through the innovative exhaust gas heater system, obtains the vehicle speed signal and the particulate trap working state signal through communication with the vehicle body controller, and drives the parallel MOSFET through PWM waves to provide a large current to the heating device at idle and start;

[0036] And based on the control method, the start-up and shutdown timing of the exhaust gas heater can be made more in line with the working conditions of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0038] Figure 1 A system block diagram of the exhaust gas heater control system provided by the present invention;

[0039] Figure 2 A schematic diagram of a flow chart of the start-up of the control method of the exhaust gas heater control system provided by the present invention;

[0040] Figure 3 A schematic flow chart of the control method of the exhaust gas heater control system provided by the present invention when it is turned off.

[0041] Illustration Description:

[0042] Main controller 100, driving power module 200, power supply module 300, communication module 400, input and output module 500, driving module 600, serial universal interface module 700;

[0043] A high-side driver 210 , a low-dropout linear regulator 310 , and a control area network transceiver 410 . DETAILED DESCRIPTION

[0044] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0045] According to the diagram, the exhaust gas heater control system provided by the present invention includes seven components: a main controller 100, a driving power module 200, a power supply module 300, a communication module 400, an input and output module 500, a driving module 600, and a serial universal interface module 700.

[0046] The power module 300, the communication module 400, the input / output module 500, the drive module 600, and the serial universal interface module 700 are all integrated on the main controller 100;

[0047] The power module 300 is connected to an external power source to supply power to all modules. The power module 300 is connected to the start-up level circuit to collect the start-up level.

[0048] The communication module 400 is connected to the vehicle body controller for communication, and the communication between the main controller 100 and the vehicle body controller is realized through the communication module 400;

[0049] The input-output module 500 is used to detect the working status of the exhaust gas heater;

[0050] The driving module 600 and the serial universal interface module 700 are both connected to the driving power module 200, and the driving power module 200 is connected to the exhaust gas heater.

[0051] The serial universal interface module 700 is used for communication with the main control 100, receiving instructions from the main control 100, controlling the drive module 600 and feeding back the state of the drive module 600;

[0052] The driving module 600 is used to send a driving level to the driving power module 200 .

[0053] The main controller 100 can obtain the vehicle speed signal and the particulate trap working status signal collected by the body controller through the communication module 400, and the main controller 100 also monitors the working status of the power module 300, the communication module 400, and the exhaust gas heater. The main controller 100 can process the vehicle speed signal and the particulate trap working status signal collected by the body controller and the working status of the power module 300 and the communication module 400 to form an exhaust gas heater opening or closing signal and send it to the driving power module 200 through the driving module 600 and the serial universal interface module 700, and the driving power module 200 thereby controls the opening and closing of the exhaust gas heater.

[0054] In actual application, based on the vehicle speed signal collected by the main controller 100 through the communication module 400, and when the starting level collected by the power module 300 is lower than the set voltage, the main controller 100 controls the drive module 600 through the serial universal interface module 700 to use PWM waves to drive the power module 200. The drive power module 200 drives the parallel MOSFET based on the signal to provide a large current to the exhaust heater. In addition, the main controller 100 controls the drive module 600 through the serial universal interface module 700 to use PWM waves to change the duty cycle based on the change of the vehicle speed signal to control the output of the exhaust heater.

[0055] Specifically, the present solution further includes a sensor module, which is placed in the particulate trap. When the sensor module detects that carbon monoxide and hydrocarbons exceed the standard, the communication module 400 sends an "EHC heater state = enable" signal to the main controller 100.

[0056] In this solution, the exhaust heater is installed in the oxidation catalyst, which is located at the front end of the particulate filter of the exhaust emission system of the fuel vehicle. The exhaust heater uses electronically controlled heating to perform high-temperature secondary combustion treatment on the particulate matter in the exhaust gas before the exhaust is discharged, so that the vehicle's emissions meet national standards.

[0057] Specifically, the main controller 100 is an MCU;

[0058] In order to further improve the reliability of the power module 300, a low voltage dropout linear regulator 310 is connected between the power module 300 and the external power supply. The low voltage dropout linear regulator 310 is used to stably convert a high voltage input into a lower voltage output to stabilize the voltage.

[0059] Furthermore, the communication module 400 is connected to a control area network transceiver 410 , and the CAN network communication between the communication module 400 and the vehicle body controller is realized through the control area network transceiver 410 .

[0060] The external interface of the input-output module 500 is connected to the exhaust heater state through a level indicator, and controls the shutdown and startup of the driving module 600 through a switch button. It is sent to the main controller 100 through high and low levels. When working, it is at a high level, and when it is at a low level, the main control 100 shuts off the output.

[0061] Two high-side drivers 210 are provided inside the driving power module 200 . The driving power module 200 increases the driving current of the driving level of the driving module 600 and provides impedance matching for the two high-side drivers 210 , driving the parallel MOSFET to provide a large current to the heating device.

[0062] Furthermore, the exhaust gas heater control system provided in the present scheme also includes a timer, which is connected to the main controller 100 respectively. The timer is configured with a heater on timing and a heater off timing. When the main controller 100 generates a signal to turn on the exhaust gas heater, the main controller 100 controls the timer to start, and the heater on timing and the heater off timing inside the timer are started at the same time. After the heater on timing of the timer expires, the main controller 100 will send a signal to turn on the exhaust gas heater.

[0063] When the heater off timing in the timer exceeds this time, the main controller 100 generates a signal to turn off the exhaust gas heater.

[0064] For the exhaust gas heater control system given in this example, this example further provides a corresponding control solution. Figure 2 , Figure 3 ,

[0065] S1: The main controller 100 monitors the exhaust gas heater through the input-output module 500, and the main controller 100 monitors the working state of the communication module 400. When the main controller 100 detects that the communication of the communication module 400 is normal, it enters the next step. When the main controller 100 detects that the communication of the communication module 400 is abnormal, the main controller 100 detects whether the switch button between the input-output module 500 and the exhaust gas heater is triggered, and when triggered, it can generate a signal to turn on the exhaust gas heater;

[0066] S2: When the main controller 100 detects that the communication of the communication module 400 is normal in S1, the main controller 100 determines whether the carbon monoxide and hydrocarbons detected by the sensor module are exceeding the standard. If the main controller 100 receives that the carbon monoxide and hydrocarbons are exceeding the standard, it generates a signal to start the exhaust heater. If the main controller 100 does not receive the exceeding standard signal, it proceeds to the next step;

[0067] S3: When the main controller 100 does not receive the exceeding signal, the main controller 100 makes a judgment based on whether it receives the regeneration state signal of the particulate trap sent by the vehicle body controller, and generates a signal to start the exhaust gas heater when the main controller 100 receives that the particulate trap is in the regeneration state;

[0068] S4: When the main controller 100 generates a signal to start the exhaust gas heater, the main controller 100 controls the timer to start. When the heater start timing configured inside the timer times out, the main controller 100 sends a signal to start the exhaust gas heater to control the exhaust gas heater to start.

[0069] S5: When the exhaust gas heater is in the on state, the main controller 100 realizes intelligent closing of the exhaust gas heater based on the internal program;

[0070] S6: When the exhaust heater starts to shut down, the drive module 600 controls the load output according to the following timing. The duty cycle gradually decreases from 100% to 0%, and decreases by 6.66% every 300 milliseconds (divided into 15 steps), which takes about 4.5 seconds in total. If an opening command is encountered during the shutdown process, the duty cycle will immediately start to increase gradually from the current duty cycle, increasing by 6.66% every 300 milliseconds until it reaches 100%, and the exhaust heater adjusts its output according to the engine speed.

[0071] Furthermore, if Figure 3 The specific process of the intelligent shutdown in S5 includes:

[0072] S5.1: The main controller 100 detects the power supply status of the power module 300. When the main controller 100 detects that the power supply of the power module 300 is normal, the main controller 100 proceeds to the next step. When the main controller 100 detects that the power supply of the power module 300 is abnormal, the main controller 100 directly generates a signal to turn off the exhaust gas heater;

[0073] S5.2: In S5.1, when the main controller 100 detects that the power supply of the power module 300 is normal, the main controller 100 detects the communication status of the communication module 400. When the main controller 100 detects that the communication of the communication module 400 is normal, it proceeds to the next step. When the main controller 100 detects that the communication of the communication module 400 is abnormal, the main controller 100 detects whether the switch button between the input-output module 500 and the exhaust gas heater is triggered. When the switch button is triggered and closed, a signal for closing the exhaust gas heater can be generated;

[0074] S5.3: When the main controller 100 detects that the communication of the communication module 400 is normal, the main controller 100 determines the heater off timing inside the timer. When the heater off timing inside the timer times out, the main controller 100 generates a signal to turn off the exhaust gas heater. If it does not time out, the next step is entered;

[0075] S5.4: When the heater off timing inside the timer has not timed out, the main controller 100 makes a judgment based on whether it has received a regeneration state signal of the particulate trap sent by the vehicle body controller. When the main controller 100 receives that the particulate trap is not in the required state and receives that the carbon monoxide and hydrocarbons sent by the vehicle body controller are not exceeding the standard, the main controller 100 can generate a signal to turn off the exhaust gas heater, otherwise it proceeds to the next step;

[0076] S5.5: The main controller 100 detects the state of the exhaust gas heater through the input-output module 500. If the state of the exhaust gas heater is abnormal, the main controller 100 can generate a signal to shut down the exhaust gas heater. If the state of the exhaust gas heater is normal, S5.1-S5.5 are repeated until the main controller 100 generates a signal to shut down the exhaust gas heater.

[0077] Furthermore, the specific process of adjusting the output according to the engine speed in S6 includes:

[0078] When the exhaust heater output PWM reaches 100%, if the engine speed is lower than 1000 rpm, the duty cycle of the exhaust heater output will slowly decrease from 100% to 86.6%, decreasing by 6.66% every 300 milliseconds. When the engine speed recovers from less than 1000 rpm to above 1050 rpm and exceeds 1050 rpm for more than ten seconds, the duty cycle of the EHC output will slowly increase from 86.6% to 100%, increasing by 6.66% every 300 milliseconds.

[0079] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An exhaust gas heater control system, characterized in that: It includes a main controller, a driving power module and a power module integrated on the main controller, a communication module, an input and output module, a driving module, and a serial universal interface module. The power module is connected to an external power supply to power all modules, and the power module is connected to a start level circuit to collect the start level. The communication module is connected to the vehicle body controller for communication, and the communication between the main controller and the vehicle body controller is realized through the communication module. The input and output module is used to detect the working state of the exhaust gas heater; the drive module and the serial universal interface module are both connected to the drive power module, and the drive power module is connected to the exhaust gas heater. The serial universal interface module is used for communicating with the main controller, receiving instructions from the main controller, controlling the drive module and feeding back the state of the drive module; The driving module is used to send a driving level to the driving power module; The main controller can obtain the vehicle speed signal and the particulate trap working state signal collected by the body controller through the communication module, and the main controller also monitors the working state of the power module, the communication module, and the exhaust gas heater. The main controller can process the vehicle speed signal and the particulate trap working state signal collected by the body controller and the working state of the power module and the communication module to form an exhaust gas heater opening or closing signal and send it to the driving power module through the driving module and the serial universal interface module, and the driving power module thereby controls the exhaust gas heater to open or close; Based on the vehicle speed signal collected by the main controller through the communication module, and when the starting level collected by the power module is lower than the set voltage, the main controller controls the drive module through the serial universal interface module to use PWM waves to drive the power module. The drive power module drives the parallel MOSFET based on the signal to provide a large current to the exhaust heater. The main controller controls the drive module through the serial universal interface module to use PWM waves to change the duty cycle based on the change of the vehicle speed signal to control the output of the exhaust heater.

2. The exhaust gas heater control system according to claim 1, characterized in that: The exhaust heater control system also includes a sensor module, which is placed in the particulate trap. When the sensor module detects that carbon monoxide and hydrocarbons exceed the standard, it sends an "EHC heater state = enable" signal to the main controller through the communication module.

3. The exhaust gas heater control system according to claim 1, characterized in that: The main controller is MCU.

4. The exhaust gas heater control system according to claim 1, characterized in that: A low voltage difference linear regulator is connected between the power supply module and the external power supply.

5. The exhaust gas heater control system according to claim 1, characterized in that: The communication module is connected to a control area network transceiver, and the CAN network communication between the communication module and the vehicle body controller is realized through the control area network transceiver.

6. The exhaust gas heater control system according to claim 1, characterized in that: The external interface of the input and output module is connected to the exhaust heater status through the level indicator, and the drive module is controlled to shut down and start through the switch button. The main controller is given a high level when working, and the main control shuts down the output when the level is low; The driving power module is internally provided with two high-side drivers, and the driving power module is used to increase the driving current of the driving level of the driving module and provide impedance matching for the two high-side drivers, and drive the parallel MOSFET to provide a large current to the heating device.

7. The exhaust gas heater control system according to claim 1, characterized in that: The exhaust gas heater control system further includes a timer, which is connected to the main controller respectively, and the timer is configured with a heater on timing and a heater off timing. When the main controller generates a signal to turn on the exhaust gas heater, the main controller controls the timer to start, and the heater on timing and the heater off timing in the timer are started at the same time. After the heater on timing of the timer times out, the main controller sends a signal to turn on the exhaust gas heater. When the heater shut-off timing inside the timer exceeds this time, the main controller generates a signal to shut down the exhaust gas heater.

8. A control method for an exhaust gas heater control system, characterized in that: include: S1: The main controller detects the exhaust gas heater through the input and output module, and the main controller monitors the working status of the communication module. When the main controller detects that the communication of the communication module is normal, it enters the next step. When the main controller detects that the communication of the communication module is abnormal, the main controller detects whether the switch button between the input and output module and the exhaust gas heater is triggered. When triggered, it can generate a signal to turn on the exhaust gas heater; S2: When the main controller 100 detects that the communication of the communication module is normal in S1, the main controller determines whether the carbon monoxide and hydrocarbons detected by the sensor module are exceeding the standard. If the main controller receives that the carbon monoxide and hydrocarbons are exceeding the standard, it generates a signal to start the exhaust heater. If the main controller does not receive the exceeding standard signal, it proceeds to the next step; S3: When the main controller does not receive the exceeding signal, the main controller makes a judgment based on whether it receives the regeneration state signal of the particulate trap sent by the body controller, and generates a signal to start the exhaust gas heater when the main controller receives that the particulate trap is in the regeneration state; S4: When the main controller generates a signal to start the exhaust gas heater, the main controller controls the timer to start. When the heater start timing configured inside the timer times out, the main controller sends a signal to start the exhaust gas heater to control the start of the exhaust gas heater. S5: When the exhaust gas heater is in the on state, the main controller realizes intelligent closing of the exhaust gas heater based on the internal program; S6: When the exhaust heater starts to shut down, the drive module controls the load output according to the following timing. The duty cycle gradually increases from 100% to 0%, and decreases by 6.66% every 300 milliseconds, which takes about 4.5 seconds in total. If an opening command is encountered during the shutdown process, the duty cycle will immediately start to increase gradually from the current duty cycle, increasing by 6.66% every 300 milliseconds until it reaches 100%, and the exhaust heater adjusts its output according to the engine speed.

9. The control method of the exhaust gas heater control system according to claim 8, characterized in that: The specific process of the intelligent shutdown in S5 includes: S5.1: The main controller detects the power supply status of the power module. When the main controller detects that the power supply of the power module is normal, the main controller proceeds to the next step. When the main controller detects that the power supply of the power module is abnormal, the main controller directly generates a signal to shut down the exhaust gas heater. S5.2: When the main controller detects that the power supply of the power module is normal in S5.1, the main controller detects the communication status of the communication module. When the main controller detects that the communication of the communication module is normal, it proceeds to the next step. When the main controller detects that the communication of the communication module is abnormal, the main controller detects whether the switch button between the input and output module and the exhaust gas heater is triggered. When the switch button is triggered and closed, a signal to close the exhaust gas heater can be generated; S5.3: When the main controller detects that the communication of the communication module is normal, the main controller determines the heater closing timing inside the timer. When the heater closing timing inside the timer times out, the main controller generates a signal to close the exhaust gas heater. If it does not time out, it proceeds to the next step. S5.4: When the heater shut-off timing inside the timer has not timed out, the main controller makes a judgment based on whether it has received a regeneration status signal of the particulate trap sent by the body controller. When the main controller receives that the particulate trap is not in the required state and receives that the carbon monoxide and hydrocarbon content sent by the body controller are not exceeding the standard, the main controller can generate a signal to shut down the exhaust heater, otherwise it proceeds to the next step; S5.5: The main controller detects the status of the exhaust gas heater through the input and output module. If the exhaust gas heater is in an abnormal state, the main controller can generate a signal to shut down the exhaust gas heater. If the exhaust gas heater is in a normal state, S5.1-S5.5 are repeated until the main controller generates a signal to shut down the exhaust gas heater.

10. The control method of the exhaust gas heater control system according to claim 8, characterized in that: The specific process of adjusting the output of the exhaust gas heater in S6 according to the engine speed includes: When the exhaust heater output PWM reaches 100%, if the engine speed is lower than 1000 rpm, the duty cycle of the exhaust heater output will slowly decrease from 100% to 86.6%, decreasing by 6.66% every 300 milliseconds. When the engine speed recovers from less than 1000 rpm to above 1050 rpm and exceeds 1050 rpm for more than ten seconds, the duty cycle of the EHC output will slowly increase from 86.6% to 100%, increasing by 6.66% every 300 milliseconds.

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