KR20230084851A - Control unit of EHC-based catalyst system - Google Patents

Abstract

The present invention relates to a control device for controlling an EHC-based catalyst system. According to the present invention, since power is supplied and operated only when a catalyst system driving request message is received from another control device, battery consumption power This can be reduced, and the heater driving unit is configured to always receive power from the battery in a state in which most components of the control device are in the sleep mode, so even when the driving request message is not received, it is determined whether the vehicle is cold started and the heater is driven. can make it

Description

Control unit of EHC-based catalyst system {Control unit of EHC-based catalyst system}

The present invention relates to a control device for controlling an EHC-based catalyst system, and more particularly, when power is supplied and operated only when a catalyst system driving request message is received from another control device, but in the case of low-temperature start-up, the device It relates to a control device configured to enable pre-heating of

In recent years, as the environmental pollution problem has emerged, exhaust gas regulations of vehicles have been gradually strengthened. Accordingly, a vehicle needs an exhaust gas post-processing means for purifying harmful substances in exhaust gas, and a catalyst system that purifies harmful components in exhaust gas by catalytic action by installing a catalyst device in the middle of the exhaust pipe will be provided as the means. can

이상에 도달해야하는 것으로 알려져 있다.On the other hand, in order for the catalyst system to exhibit its purification function, the catalyst must be activated. The activation temperature for the catalyst to exhibit its function is approximately 300 ~ 400

It is known to reach the ideal.

However, since the temperature of the exhaust gas is low and the temperature of the cooling water is low in the low-temperature start (cold start) state of the engine, it takes some time (approximately 100 seconds after start-up) for the catalyst to heat up and reach the activation temperature. .

Therefore, under the cold starting condition of the vehicle, the catalyst system does not perform its function and is not purified, and exhaust gas containing a large amount of unburned hydrocarbons or carbon monoxide is discharged as it is, which is an important factor in air pollution.

As a conventional technique for preventing the above problem, after a heater is provided at the front end of the catalyst system, when the vehicle is started (ignition is on), it is determined that the car is cold and the heater is operated to increase the temperature of the exhaust gas and A technique for promoting rapid activation of a catalyst is disclosed. At this time, the heater is also called EHC (Electrically Heated Catalyst) in the art and may be configured to generate heat at a predetermined temperature by receiving current through an Electronic Control Unit (ECU).

Meanwhile, the basic operating principle of the EHC-based catalyst system is disclosed in Patent Registration No. 10-1491297 and Patent Publication No. 10-2018-0029678.

Korean Registered Patent Publication No. 10-1491297 Korean Patent Publication No. 10-2018-0029678

An object of the present invention is to provide a control device for an EHC-based catalyst system capable of reducing battery power consumption.

In addition, an object of the present invention is to provide a control device for an EHC-based catalyst system capable of controlling preheating (pre-heating) of the catalyst system according to temperature conditions while achieving the aforementioned reduction in battery power consumption. to be

An embodiment of the present invention for achieving the above object is a control device for controlling the driving of an electrically heated catalyst (EHC)-based catalyst system, which receives external power from a battery provided outside the control device, and when enabled, a power supply unit operable to convert the external power into internal power to be supplied to at least one component included in the control device; a heater driver controlling a heater of the catalyst system to heat the catalyst of the catalyst system; a blower driving unit controlling a blower of the catalyst system to supply air to the catalyst system; a communication unit that communicates with other control devices and receives a driving request message for the catalyst system; and a main controller configured to control the heater driving unit and the blower driving unit to operate when the communication unit receives the driving request message.

Here, the power unit may be enabled to supply the internal power when the communication unit receives the driving request message.

At this time, the heater driving unit operates while being directly connected to the external power source, and is enabled when an ignition signal is input, and even when the communication unit does not receive the driving request message, the heater driving unit operates according to a temperature measurement result of the catalyst system. drive can be controlled.

The heater driver may be connected to a negative temperature coefficient thermistor (NTC) sensor that measures the temperature of the catalyst system, and may drive the heater when the temperature of the catalyst system is lower than a predetermined level.

In addition, the communication unit operates while being directly connected to the external power supply, wakes up upon receiving the drive request message, and transmits a drive request signal output as HIGH in the wakeup state to the power supply unit. It can be transmitted to the main control unit.

In addition, the main control unit may control the communication unit to switch to a sleep mode when the driving request message is not received.

At this time, the communication unit may output the driving request signal as low in the sleep mode.

In addition, the main control unit may diagnose a failure of the communication unit according to the state of the driving request signal.

In addition, the main control unit may determine that the communication unit has a failure when the driving request signal received after controlling the switching unit to the sleep mode is HIGH.

In addition, the main control unit operates by receiving the internal power and maintains the internal power for a predetermined time even after the driving request signal is turned low. Configured to operate in a power latch mode It can be.

In this case, the main control unit may transmit a power latch signal output as high in the power latch mode to the power supply unit.

In this case, the power unit may be enabled when at least one of the power latch signal and the driving request signal is HIGH.

Meanwhile, the blower driving unit may operate by receiving the internal power.

Meanwhile, the communication unit may receive the driving request message from the other control device using a CAN communication BUS.

According to the present invention, since power is supplied and operated only when a catalyst system drive request message is received from another control device, battery consumption power can be reduced.

In addition, according to the present invention, the heater driving unit is configured to always receive power from the battery in a state in which most components of the control device are in the sleep mode, so that even when the driving request message is not received, it is determined whether the vehicle is cold started and the heater is turned on. can drive

1 is a block diagram of a control device for an EHC-based catalyst system according to an embodiment of the present invention.
FIG. 2 is a configuration diagram showing a connection line through which signals are transmitted between each component in FIG. 1 in more detail.
3 is a table showing conditions under which the power unit is enabled.
4 is a table showing driving states of heaters and blowers when a driving request message is received or not received.
FIG. 5 shows a flow of a control method of an EHC-based catalyst system performed by the control device of FIG. 1 .

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. This is not intended to limit the present invention to specific embodiments, and should be construed as including all changes, equivalents, or substitutes included in the spirit and technical scope of the present invention.

In describing the present invention, terms such as first and second may be used to describe various components, but the components may not be limited by the terms. These terms are only for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention.

The term "and/or" may include any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected or connected to the other component, but other components may exist in the middle. can be understood On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it may be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions may include plural expressions unless the context clearly dictates otherwise.

In this application, terms such as "comprise" or "having" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features It may be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries may be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, interpreted in an ideal or excessively formal meaning. It may not be.

In addition, the following embodiments are provided to more completely explain to those with average knowledge in the art, and the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

FIG. 1 is a block diagram of a control device 10 of an EHC-based catalyst system according to an embodiment of the present invention, and FIG. 2 is a block diagram showing connection lines through which signals are transmitted between components in FIG. 1 in more detail.

1 and 2, the control device 10 of the EHC-based catalyst system according to an embodiment of the present invention includes a power supply unit 100, a heater driving unit 200, a blower driving unit 300, a communication unit 400, and a main A controller 500 may be included.

The power supply unit 100 is connected to a battery 1 provided outside the control device 10 and is configured to receive external power from the battery 1 . Here, the battery 1 may be a 12V lead acid battery installed in a vehicle.

The power supply unit 100 is enabled when a specific signal is input to the enable terminal EN. When enabled, the power supply unit 100 supplies external power of 12V to at least one component included in the control device 10. (VCC). Conversion at this time may mean voltage step-down, and for example, a 12V external power supply may have a voltage step-down of a 5V internal power supply. The power supply unit 100 may be a regulator IC. As is well known, the regulator IC converts (VCC) a signal input to the input terminal (in) (battery 1 power supply) into a predetermined size and outputs it through the output terminal (OUT).

The main control unit 500 and the blower driving unit 300, which will be described later, may be driven by receiving the internal power source VCC.

The heater driver 200 to be described later may be driven by being directly connected to an external power source. The communication unit 400 is driven by being connected to an external power source, but may be switched to a sleep mode when a driving request message is not received.

In other words, only some components of the control device 10 of the present invention are connected to an external power source, and other components are driven by receiving an internal power source (VCC). The power supply unit 100 that supplies the internal power source VCC is configured to be enabled under a specific condition instead of being enabled simultaneously with the input of the ignition signal 7, so that power consumption of the battery 1 can be reduced.

In this case, the specific condition may be a case in which the communication unit 400, which will be described later, receives a driving request message requesting driving of the catalyst system from another control device 30. A detailed operation will be described later.

The heater driver 200 may control the heater 2 to heat the catalyst of the catalyst system. The control may mean supplying current to the heater 2 for a predetermined time.

The blower driver 300 may control the air blower 3 to supply air to the catalyst system. The control may mean that an air blower 3 sends a control signal to supply air to the catalyst system. Here, as is well known, the air blower 3 serves to supply secondary air to the exhaust pipe to help oxidize carbon monoxide and hydrocarbons. The secondary air supplied by the air blower 3 oxidizes carbon hydrogen, and nitrogen oxides adsorbed in the catalyst can be effectively purified by the reducing gas generated at this time. In another embodiment, an air pump may be provided instead of the air blower 300 . At this time, the blower driving unit 300 may be configured to control the air pump rather than the air blower 3 .

The heater driving unit 200 and the blower driving unit 300 may be circuit modules driven according to an ON/OFF request including components such as a driver IC or FET.

The communication unit 400 may communicate with other control devices 30 to receive a drive request message for the catalyst system. Here, the other control device 30 is a client that generates and transmits the driving request message, and other electronic control units (ECUs) installed in the vehicle may become the client.

For example, the other control device 30 may be an ECU that controls an engine. The engine control ECU may receive catalyst temperature information and transmit a driving request message to the communication unit 400 of the control device 10 based on the received catalyst temperature information.

For example, the other control device 30 may be an ECU that receives vehicle temperature information. In this case, even if the temperature information of the catalyst is not the same, when the temperature of the vehicle is lower than a preset level, it may be determined that the vehicle is cold started and a driving request message may be sent to the communication unit 400 of the control device 10 according to the present invention.

Communication between the communication unit 400 and the other control device 30 may be based on a controller area network (CAN) communication protocol provided in the vehicle. That is, the communication unit 400 may receive a drive request message from a communication unit (not shown) of the other control device 30 using a CAN communication BUS.

In this way, when controlling the driving of the catalyst system using the communication BUS, the use of a large amount of relay circuits, wiring harnesses, etc. is reduced compared to when wiring is connected one-to-one with other control devices 30 as in the prior art. There are advantages that can be

The main control unit 500 controls the heater driving unit 200 and the blower driving unit 300 to operate when the communication unit 400 receives a driving request message from the other control device 30 .

The main control unit 500 may operate by internal power supplied after the power unit 100 is enabled. The main control unit 500 operates in a power latch mode for a predetermined time so that the supply of internal power (VCC) from the power supply unit 100 is maintained even when the drive request signal INH_STATE is turned low. can do.

The main control unit 500 may output the power latch signal PWL as HIGH for a preset time after the drive request signal INH_STATE is converted to LOW. The power latch signal PWL may be transmitted to the power supply unit 100 . The power supply unit 100 may operate to maintain supply of the internal power supply VCC while receiving the power latch signal PWL. That is, the enabled state can be maintained.

When the drive request signal INH_STATE becomes HIGH and the power supply 100 is enabled, the main controller 500 receives the internal power VCC from the power supply 100 and outputs the power latch signal PWL as HIGH. there is. The main control unit 500 may be configured to maintain the power latch signal PWL at HIGH for a preset time from the time when the driving request signal INH_STATE is switched from HIGH to LOW.

Accordingly, the main control unit 500 may perform control or operation for a preset power latch mode time without being immediately turned off even after the drive request signal INH_STATE is turned to LOW.

The main control unit 500 may control the communication unit 400 to switch to a sleep mode when the communication unit 400 does not receive a driving request message. For control of the communication unit 400, SPI (Serial Peripheral Interface) communication may be used. As is well known, SPI is one of the serial communication methods. However, it is not limited thereto, and UART communication may be used to control the communication unit 400 .

The communication unit 400 outputs the driving request signal INH_STATE as LOW in the sleep mode.

At this time, the main control unit 500 is configured to diagnose a failure of the communication unit 400 according to the state of the drive request signal INH_STATE. More specifically, if the drive request signal INH_STATE received from the communication unit 400 after the main controller 500 controls the communication unit 400 to switch to the sleep mode is HIGH, the communication unit 400 is not switched to sleep mode. Accordingly, at this time, the main control unit 500 may determine that the communication unit 400 is in a failure state.

Hereinafter, a catalyst system control operation of the control device 10 of the present invention interlocked with reception of a driving request message will be described.

The communication unit 400 wakes up when receiving a drive request message from another control device 30 through CAN communication. When the communication unit 400 is in a wakeup state, the drive request signal INH_STATE is output as HIGH. The communication unit 400 is directly connected to the battery 1, which is an external power source, so that it can operate immediately upon reception of a CAN communication message.

The communication unit 400 is connected to the power supply unit 100 and the main control unit 500, respectively, and the driving request signal INH_STATE output is transmitted to the power supply unit 100 and the main control unit 500.

The driving request signal INH_STATE transmitted to the power supply unit 100 is input to the enable terminal EN of the power supply unit 100 . As is well known, the power supply unit 100 is enabled when a HIGH signal is input to the enable terminal and disabled when a LOW signal is input. That is, when the drive request signal INH_STATE is HIGH, the power supply unit 100 may be enabled. The enabled power supply unit 100 outputs the internal power supply VCC and transfers it to each component of the control device 10 .

The internal power (VCC) supplied from the power supply unit 100 is also transmitted to the main control unit 500, and the operation of the main control unit 500 is started. The main control unit 500 may receive the driving request signal INH_STATE from the communication unit 400 and control the heater driving unit 200 and the blower driving unit 300 to operate.

At this time, the heater driver 200 is directly connected to the battery 1, which is an external power source, and is enabled by the ignition signal 7 to operate, and the blower driver 300 has internal power supplied from the power source 100. (VCC) is supplied and can be operated.

Meanwhile, the power supply unit 100 is connected to the communication unit 400 and the main control unit 500 to receive both the drive request signal INH_STATE and the power latch signal PWL. More specifically, a line connected through R _C and D1 in FIG. 2 is a line through which the power latch signal PWL is transmitted. Lines connected through R _a , R _{b ,} and D ₂ are lines through which the driving request signal INH_STATE is transmitted. That is, the power supply unit 100 can receive not only the drive request signal INH_STATE but also the power latch signal PWL, and can be enabled when at least one of the two signals is HIGH.

3 is a table showing conditions under which the power supply unit 100 is enabled.

Referring to FIG. 3 , it can be seen that the power supply unit 100 is enabled when either one of the drive request signal INH_STATE and the power latch signal PWL is HIGH in Cases 1 and 3. In case 2 in which all signals are LOW, the power supply unit 100 is disabled.

This is also true for Case 4. To describe Case 4 in detail, the driving request signal INH_STATE is output as HIGH when the communication unit 400 receives the drive request message, and then the power latch signal PWL is output as HIGH after being converted to LOW. Even at this time, the power supply unit 100 is enabled.

However, if the driving request signal (INH_STATE) is not switched from HIGH to LOW but is continuously in the LOW state as in Case 5, since the power supply unit 100 cannot be enabled in the first place, the power latch signal (PWL) is also output as HIGH. can't That is, Case 5 is an impossible signal state unlike Case 4.

In this way, unlike the prior art, the enable terminal (EN) of the power supply unit 100 is connected to the communication unit 400 and the main control unit 500 instead of the ignition signal 7 to enable the internal power supply for each configuration ( Whether VCC) is supplied can be controlled according to the driving necessity of the catalyst system.

Through this, there is an advantage in that power consumption of the battery 1 is reduced. As the number of electronic devices in a vehicle increases, such power saving is an essential task to increase the overall efficiency of vehicle systems.

However, it is undesirable that the efficiency of the catalyst system is excessively reduced while saving power.

In this regard, an operation of preheating the catalyst system will be described below without enabling the power supply unit 100, that is, without supplying power to the main control unit 500 and the communication unit 400 of the control device 10.

As described above, the heater driving unit 200 included in the control device 10 according to the embodiment of the present invention may operate while being directly connected to an external power source.

The heater driver 200 is enabled when the ignition signal 7 is input. In other words, the enable terminal EN of the heater driver 200 is connected to the ignition signal 7 so that the heater driver 200 is enabled when the ignition signal 7 is input.

The heater driver 200 may be configured to be connected to a negative temperature coefficient thermistor (NTC) sensor 5 that measures the temperature of the catalyst system. The heater driving unit 200 may control driving of the heater 2 according to the temperature measurement result of the catalyst system by the NTC sensor 5 even when the communication unit 400 does not receive the driving request message.

The heater driving unit 200 may control the heater 2 to be driven when the temperature of the catalyst system is lower than a preset level as a result of measuring the temperature.

More specifically, referring to FIG. 2, the NTC sensor 5 installed inside the catalyst measures the temperature of the catalyst. When the ignition is turned on by startup, the ignition voltage (12V) is divided by R_PU and NTC and input to the Gate of NMOSFET (M1). As is well known, the NTC sensor 5 is an element whose resistance value increases as the temperature decreases. R_PU may be preset considering the resistance value of the NTC sensor 5 and the threshold voltage value of the NMOSFET M1 at the low temperature threshold level to be detected.

At this time, the NMOSFET (M1) is turned on only when the catalyst temperature is lower than the predetermined threshold level while the ignition is on, and the ignition voltage is divided by R1 and R2 and R _DS of the NMOSFET (M1). , the divided voltage may be transmitted as an input signal for driving the heater driver 200 through D3.

That is, looking at the input terminal (IN) of the heater driver 200, a line to which a signal is input through D3 is a path of an input signal for preheating the catalyst system.

Meanwhile, in the above case, since the power supply unit 100 is in a disabled state, the main control unit 500 is in a state in which the internal power supply VCC is not supplied from the control device 10 . That is, among the internal configurations of the control device 10, the heater driver 200 is the only one that operates. With this configuration, cold starting of the vehicle can be sensed and the catalyst system can be preheated with little power.

Again, looking at the input terminal (IN) of the heater driver 200, the line to which the signal is input through D4 is a case where the communication unit 400 receives a driving request message from the other control device 30, and the main control unit 500 ) is the path through which the input signal is transmitted. At this time, as described above, the blower driving unit 300 also operates together.

To summarize, operation modes of the heater driving unit 200 can be divided into two types.

The first operation mode is an operation mode for preheating the catalyst of the catalyst system, and is a mode in which only the heater driver 200 in the control device 10 is enabled to drive the heater 2 .

The second operation mode is an operation mode accompanying driving the catalyst system, wherein the power supply unit 100 of the control device 10 is enabled and the main control unit 500 operates both the heater driving unit 200 and the blower driving unit 300. This is the operating mode when operating.

4 is a table showing driving states of the heater 2 and the air blower 3 when a driving request message is received or not received.

Referring to FIG. 4 , when the communication unit 400 receives a driving request message, the heater 2 and the air blower 3 are driven regardless of the temperature of the catalyst. When the communication unit 400 does not receive the driving request message, only the heater 2 is driven and the air blower 3 is not driven when the temperature of the catalyst is lower than a preset level. The operation of each component at the time of reception and non-reception of the drive request message has been described above.

FIG. 5 shows the flow of a control method of the EHC-based catalyst system performed by the control device 10 of FIG. 1 .

Referring to FIG. 5 , the control method of the EHC-based catalyst system performed by the control device 10 of FIG. 1 includes an ignition on step (S100), a driving request message receiving step (S300), and a controller internal power supply step (S400). and a catalyst system driving step (S500).

The driving request message receiving step (S300) is a step in which the communication unit 400 receives a driving request message requesting driving of the catalyst system from another control device 30 through a CAN communication BUS.

In this step (S300), the communication unit 400, which was in the sleep mode before receiving the driving request message, may wake up and output the driving request signal INH_STATE to HIGH. The output driving request signal INH_STATE is transmitted to the power supply unit 100 and the main control unit 500 .

Upon receiving the drive request signal INH_STATE in this step (S300), the main control unit 500 may output the power latch signal PWL as HIGH. The output power latch signal PWL is also transferred to the power supply unit 100 .

The controller internal power supply step ( S400 ) is a step in which the power supply unit 100 receives a HIGH drive request signal (INH_STATE) from the communication unit 400 and enables it.

The power supply unit 100 may be enabled by receiving a HIGH power latch signal PWL from the main control unit 500 . That is, the power supply unit 100 is enabled by receiving a HIGH signal from the communication unit 400 or the main control unit 500, and is disabled when both the communication unit 400 and the main control unit 500 receive a LOW signal.

The power unit 100 enabled in this step (S400) converts the external power of 12V, which is the power of the battery 1, into internal power (VCC) to be supplied to at least one component included in the control device 10, print out

The catalyst system driving step (S500) is a step in which the main control unit 500 controls the heater driving unit 200 and the blower driving unit 300 to operate the heater 2 and the air blower 3 of the catalyst system. The main control unit 500 may control the heater driving unit 200 and the blower driving unit 300 to operate when receiving the drive request signal INH_STATE from the communication unit 400 .

In this step (S500), the heater driver 200 may control the catalyst to be heated by supplying current to the heater 2. In this step (S500), the blower driving unit 300 may control the blower to supply air to the catalyst system.

Meanwhile, a pre-heating step ( S200 ) of preheating the catalyst system in a state in which a drive request message is not received after the ignition-on step ( S100 ) may be further included.

In this step (S200), the heater driving unit 200 controls the driving of the heater 2 according to the temperature measurement result of the catalyst system by the NTC sensor 5 even in a state where the communication unit 400 has not received the driving request message. can The heater driving unit 200 may control the heater 2 to be driven when the temperature of the catalyst system is lower than a preset level as a result of measuring the temperature.

As described above, according to the present invention, since power is supplied and operated only when a catalyst system driving request message is received from another control device, battery consumption power can be reduced.

In addition, according to the present invention, the heater driving unit is configured to always receive power from the battery in a state in which most components of the control device are in the sleep mode, so that even when the driving request message is not received, it is determined whether the vehicle is cold started and the heater is turned on. can drive

On the other hand, although the present invention has been described with limited embodiments and drawings, the present invention is not limited to the above embodiments, and various modifications and variations can be made from these descriptions by those skilled in the art in the field to which the present invention belongs. do. Therefore, the technical spirit of the present invention should be grasped only by the claims, and all equivalent or equivalent modifications thereof will be said to belong to the scope of the technical spirit of the present invention.

1: Battery
2: Heater (EHC)
3: air blower
10: Control unit of the EHC-based catalyst system
100: power supply
200: heater driving unit
300: blower driving unit
400: communication department
500: main control unit
30: other control device

Claims (11)

As a control device that controls the operation of an EHC (Electrically Heated Catalyst) based catalyst system,
a power supply unit that receives external power from a battery provided outside the control device and operates to convert the external power into internal power to be supplied to at least one component included in the control device when enabled;
a heater driver controlling a heater of the catalyst system to heat the catalyst of the catalyst system;
a blower driving unit controlling a blower of the catalyst system to supply air to the catalyst system;
a communication unit that communicates with other control devices and receives a driving request message for the catalyst system; and
When the communication unit receives the driving request message, a main control unit controlling the heater driving unit and the blower driving unit to operate;
the power supply,
Characterized in that when the communication unit receives the driving request message, it is enabled to supply the internal power.
Control unit for EHC-based catalytic systems.
According to claim 1,
The heater driver,
It operates by being directly connected to the external power source,
It is enabled when an ignition signal is input, and the communication unit controls driving of the heater according to the temperature measurement result of the catalyst system even in a state where the driving request message is not received.
Control unit for EHC-based catalytic systems.
According to claim 2,
The heater driver,
Characterized in that it is connected to a negative temperature coefficient thermistor (NTC) sensor that measures the temperature of the catalyst system and drives the heater when the catalyst system is at a lower temperature than a preset level.
Control unit for EHC-based catalytic systems.
According to claim 1,
The communication department,
It operates by being directly connected to the external power source,
Characterized in that, upon receiving the drive request message, a drive request signal that wakes up and is output as HIGH in the wakeup state is transmitted to the power supply unit and the main control unit.
Control unit for EHC-based catalytic systems.
According to claim 4,
The main control unit,
Controlling the communication unit to switch to a sleep mode when the driving request message is not received;
The communication department,
Characterized in that the drive request signal is output as low in the sleep mode.
Control unit for EHC-based catalytic systems.
According to claim 5,
The main control unit,
Characterized in that the failure of the communication unit is diagnosed according to the state of the drive request signal,
Control unit for EHC-based catalytic systems.
According to claim 6,
The main control unit,
Determining that the communication unit is out of order when the driving request signal received after controlling the communication unit to switch to the sleep mode is HIGH;
Control unit for EHC-based catalytic systems.
According to claim 4,
The main control unit,
It operates by receiving the internal power supply,
It is configured to operate in a power latch mode that maintains the internal power for a predetermined time even after the drive request signal is switched to low,
Characterized in that the power latch signal output as HIGH in the power latch mode is transmitted to the power supply unit,
Control unit for EHC-based catalytic systems.
According to claim 8,
the power supply,
Characterized in that it is enabled when at least one of the power latch signal and the drive request signal is HIGH.
Control unit for EHC-based catalytic systems.
According to claim 1,
The blower drive unit,
Characterized in that it operates by receiving the internal power supply,
Control unit for EHC-based catalytic systems.
According to claim 1,
The communication department,
Characterized in that the drive request message is received from the other control device using a CAN communication BUS,
Control unit for EHC-based catalytic systems.

Images