JP2022036488A - Control device - Google Patents

Abstract

To provide a control device capable of determining abnormality in a power supply circuit for an electric heating-type catalyst.SOLUTION: A control device 10 includes: a heat quantity setting portion 11 for setting a target heat quantity; a power supply portion 12 for performing a power supply processing as a processing for supplying power for power generation to an electric heating-type catalyst 200 so that the set target heat quantity is generated in the electric heating-type catalyst; a temperature acquisition portion 13 for acquiring a temperature of the electric heating-type catalyst 200; and an abnormality determination portion 15 for determining abnormality in a power supply circuit to supply the power for power generation to the electric heating-type catalyst 200. The abnormality determination portion 15 determines the abnormality in the power supply circuit on the basis of comparison of an arrival temperature of the electric heating-type catalyst 200 in performing the power supply processing, with a prescribed threshold temperature.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a control device for an electrically heated catalyst.

The vehicle is provided with a catalyst device for purifying the exhaust gas. The catalyst device is a device that purifies harmful substances such as nitrogen oxides contained in exhaust gas by passing them through a high-temperature catalyst. In order for the catalyst device to function, it is necessary to keep the temperature of the catalyst above a predetermined active temperature.

In recent years, for example, for the purpose of purifying exhaust gas from an early stage at the time of cold start, studies have been made on mounting an electric heating type catalyst on a vehicle. In the electric heating type catalyst, the catalyst can be heated by the electric power for heat generation supplied from the outside, and the temperature of the catalyst can be quickly reached to the active temperature. Therefore, even at the time of cold start when the temperature of the exhaust gas is relatively low, it is possible to start the purification of the exhaust gas in a short time. The following Patent Document 1 describes the configuration and the like of such an electrically heated catalyst.

Japanese Unexamined Patent Publication No. 2010-2012

When supplying electric power for power generation to an electrically heated catalyst, a target value of the electric power is set in advance. The target value can be said to be the energy required to bring the temperature of the electrically heated catalyst to the active temperature. When the electric energy for heat generation supplied to the electric heating catalyst reaches the target value, the supply of the electric power for heat generation is stopped.

If an abnormality occurs in the power supply circuit for supplying electric power for power generation to the electric heating type catalyst, the temperature of the electric heating type catalyst cannot be appropriately controlled. Therefore, when an abnormality occurs in the power supply circuit, it is necessary to detect the abnormality. However, a specific method for detecting an abnormality in a power supply circuit has not been conventionally studied.

It is an object of the present disclosure to provide a control device capable of determining an abnormality in a power supply circuit for an electrically heated catalyst.

The control device according to the present disclosure is a control device (10) of an electric heating type catalyst (200), and a calorific value setting unit (11) for setting a target calorific value and a set target calorific value are generated by the electric heating type catalyst. As described above, the electric power supply unit (12) that performs the electric power supply process, which is the process of supplying electric power for power generation to the electric heating type catalyst, the temperature acquisition unit (13) that acquires the temperature of the electric heating type catalyst, and the electric heating unit. The equation includes an abnormality determination unit (15) for determining an abnormality in the power supply circuit for supplying electric power for power generation to the catalyst. The abnormality determination unit determines an abnormality in the power supply circuit based on a comparison between the temperature reached by the electrically heated catalyst when the power supply process is performed and a predetermined threshold temperature.

When an abnormality occurs in the power supply circuit, the temperature reached by the electrically heated catalyst when the power supply process is performed becomes a temperature different from the temperature reached in the normal state. Therefore, in the control device having the above configuration, the abnormality determination unit determines the abnormality in the power supply circuit based on the comparison between the reached temperature of the electric heating type catalyst when the power supply processing is performed and the predetermined threshold temperature. I'm supposed to do it. This makes it possible to determine an abnormality in the power supply circuit.

According to the present disclosure, there is provided a control device capable of determining an abnormality in a power supply circuit for an electrically heated catalyst.

FIG. 1 is a diagram schematically showing a configuration of a control device according to the first embodiment and a configuration of a vehicle on which the control device is mounted. FIG. 2 is a cross-sectional view showing the configuration of the electrically heated catalyst shown in FIG. FIG. 3 is a cross-sectional view showing the configuration of the electrically heated catalyst shown in FIG. FIG. 4 is a diagram showing the relationship between the temperature and the resistance value of the electrically heated catalyst. FIG. 5 is a diagram for explaining temperature control of the electrically heated catalyst. FIG. 6 is a diagram for explaining temperature control of the electrically heated catalyst. FIG. 7 is a flowchart showing a flow of processing executed by the control device shown in FIG. FIG. 8 is a flowchart showing a flow of processing executed by the control device shown in FIG. FIG. 9 is a flowchart showing a flow of processing executed by the control device according to the second embodiment. FIG. 10 is a flowchart showing a flow of processing executed by the control device according to the second embodiment.

Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as possible in the drawings, and duplicate description is omitted.

The control device 10 according to the present embodiment is a device for controlling the electric heating type catalyst 200, and is mounted on the vehicle MV together with the electric heating type catalyst 200. Prior to the description of the control device 10, the configuration of the vehicle MV will be described first with reference to FIG.

As shown in FIG. 1, the vehicle MV includes an internal combustion engine 100 and an exhaust pipe 20. The internal combustion engine 100 is a so-called engine, which is a device that generates a driving force for traveling of a vehicle MV by burning fuel. The exhaust pipe 20 is a pipe for guiding the exhaust gas generated by the internal combustion engine 100 to the outside of the vehicle MV and discharging it. Note that, in FIG. 1, only a part of the configuration of the vehicle MV is schematically shown, and the illustration of other configurations included in the vehicle MV, such as intake pipes and wheels, is omitted.

An electric heating type catalyst 200, which is a control target of the control device 10, is provided at a position in the middle of the exhaust pipe 20. The electric heating catalyst 200 is a device for purifying harmful substances such as nitrogen oxides contained in exhaust gas. The configuration of the electrically heated catalyst 200 will be described with reference to FIGS. 2 and 3. FIG. 2 schematically shows a cross section of the electrically heated catalyst 200 when it is cut in a plane parallel to the direction in which the exhaust gas flows. FIG. 3 schematically shows a cross section of the electrically heated catalyst 200 when it is cut in a plane perpendicular to the direction in which the exhaust gas flows. As shown in both figures, the electrically heated catalyst 200 includes an outer cylinder 210, a base material 220, an electrode 230, and a holding member 240.

The outer cylinder 210 is a member for accommodating and holding the base material 220 and the like, which will be described later, inside. The shape of the outer cylinder 210 is generally a cylindrical shape. As shown in FIG. 2, the portion of the exhaust pipe 20 in the vicinity of the outer cylinder 210 is expanded in diameter according to the inner diameter of the outer cylinder 210, and the exhaust pipe 20 having the diameter expanded in this way is the outer cylinder 210. Is connected to. Therefore, the outer cylinder 210 is a part of the exhaust pipe 20 that guides the exhaust gas to the outside.

The base material 220 is a cylindrical member made of conductive ceramics. A plurality of flow paths 221 are formed in a honeycomb shape on the base material 220. Each flow path 221 is formed so as to extend along a direction along the central axis of the base material 220. The direction is the left-right direction in FIG. 2 and the paper depth direction in FIG. A catalyst (not shown) is supported on the base material 220. With such a configuration, the conductivity of the base material 220 is ensured. When the exhaust gas flows through each flow path 221 of the base material 220, it flows while touching the catalyst exposed on the surface of the flow path 221. As the catalyst, various materials known as metal catalysts for purifying exhaust gas, such as a three-way catalyst, can be used.

The electrodes 230 are a pair of electrodes for supplying electric power from the outside to the base material 220 that functions as a catalyst. When a voltage is applied between the electrodes 230, a current flows through the base material 220 made of conductive ceramics, and the generated Joule heat raises the temperature of the base material 220. Therefore, when the temperature of the exhaust gas is relatively low, for example, at the time of cold start, the temperature of the base material 220 is raised by supplying electric power from the electrode 230, and the base material 220 is set to the active temperature in a short time. Can be reached. The "active temperature" is the temperature of the base material 220 that can sufficiently exert the purification performance of the exhaust gas.

Hereinafter, the temperature of the base material 220 is also referred to as “the temperature of the electrically heated catalyst 200”. Further, since the electric power supplied from the pair of electrodes 230 to the base material 220 is the electric power for causing the electric heating type catalyst 200 to generate heat and raising the temperature thereof, the electric power is referred to below as "electric power for heat generation". It is also written as ".

As shown in FIG. 3, the electrode 230 has a surface electrode portion 231, a protruding portion 232, and a terminal portion 233. The surface electrode portion 231 is an electrode formed so as to cover a part of the surface of the base material 220. The surface electrode portions 231 are formed on the surface of the base material 220 at two locations facing each other with the central axis of the base material 220 interposed therebetween. As the material of the surface electrode portion 231, a metal having conductivity or the like is used.

The protruding portion 232 is a member formed so as to project outward from the surface of each surface electrode portion 231. As the material of the protrusion 232, a conductive metal or the like is used as in the surface electrode portion 231. One end of the protrusion 232 is joined to the surface electrode portion 231. One protrusion 232 is provided for each surface electrode portion 231.

The terminal portion 233 is a rod-shaped member formed so as to project further outward from the end portion of the protruding portion 232 on the side opposite to the surface electrode portion 231. As the material of the terminal portion 233, a metal member having conductivity is also used. One end of the terminal portion 233 is joined to the protruding portion 232. One terminal portion 233 is provided for each protruding portion 232.

The portion of the terminal portion 233 opposite to the protruding portion 232 projects to the outside of the outer cylinder 210 via the insulating holding member 211. Wiring for supplying heat generation power is connected to the outside of the outer cylinder 210 of the terminal portion 233. That is, each terminal portion 233 functions as an electrode terminal for receiving heat generation power from the outside.

As shown in FIG. 3, the entire surface of the conductive member including the surface electrode portion 231 and the protruding portion 232 and the base material 220 is covered with the insulating layer 250. As a result, electrical insulation between these conductive members and the outer cylinder 210 is ensured.

The holding member 240 is a member for holding the base material 220 inside the outer cylinder 210. As the holding member 240, for example, fibrous alumina is used. The holding member 240 is arranged so as to fill the entire gap formed between the inner peripheral surface of the outer cylinder 210 and the outer peripheral surface of the base material 220.

The configuration of the control device 10 will be described with reference to FIG. 1 again. As described above, the control device 10 is a device for controlling the electrically heated catalyst 200. The control device 10 is configured as a computer device having a CPU, ROM, RAM, and the like. The control device 10 includes a heat quantity setting unit 11, a power supply unit 12, a temperature acquisition unit 13, an outside air temperature acquisition unit 14, an abnormality determination unit 15, and a drive circuit 16 as block elements representing the functions thereof. I have.

The calorific value setting unit 11 is a portion that performs a process of setting a target calorific value. The "target calorific value" is set as a target value for the calorific value generated by the electric heating type catalyst 200 when supplying electric power for heat generation to the electric heating type catalyst 200. In the present embodiment, the above-mentioned target heat quantity is set as the integrated value of the heat generation power supplied to the electric heating type catalyst 200, that is, the target value for the “electric energy amount”. In the normal state, when the calorific value of the electric power corresponding to the target heat is supplied to the electric heating type catalyst 200, the target by the heat amount setting unit 11 is such that the temperature of the electric heating type catalyst 200 becomes the active temperature. The amount of heat is set. However, as will be described later, when determining an abnormality in the power supply circuit, a target heat quantity different from the above may be set.

The electric power supply unit 12 is a portion that performs a process of supplying electric power for heat generation to the electric heating type catalyst 200. The power supply unit 12 adjusts the magnitude of the heat generation power supplied to the electric heating type catalyst 200 by controlling the operation of the drive circuit 16 described later. The power supply unit 12 performs a process of supplying electric power for power generation to the electric heating type catalyst 200 so that the target heat amount set by the heat amount setting unit 11 is generated by the electric heating type catalyst 200. This process will also be referred to as "power supply process" below. In the normal state where no abnormality has occurred in the circuit for supplying electric power for power generation to the electric heating catalyst 200, when the electric power supply processing is performed, the electric heating catalyst 200 will generate a target amount of heat.

The temperature acquisition unit 13 is a portion that performs a process of acquiring the temperature of the electrically heated catalyst 200. The temperature acquisition unit 13 of the present embodiment acquires the resistance value of the base material 220 to which the power for heat generation is supplied, and acquires the temperature of the base material 220, that is, the temperature of the electric heating type catalyst 200 based on the resistance value. ..

The line L10 in FIG. 4 shows an example of the correspondence between the temperature of the base material 220 (horizontal axis) and the resistance value of the base material 220 (vertical axis). The base material 220 according to the present embodiment has a so-called PTC characteristic in which the resistance value increases as the temperature increases. The counter relationship shown by the line L10 is stored in advance as a map in a storage device (not shown) included in the control device 10.

The temperature acquisition unit 13 acquires the voltage and current values of the heat generation power supplied to the electrically heated catalyst 200 by sensors (not shown), and calculates the resistance value of the base material 220 based on these values. .. After that, the temperature of the base material 220 is acquired based on the corresponding relationship between the resistance value and the line L10 stored in a storage device (not shown).

The base material 220 may be configured to have a so-called NTC characteristic in which the resistance value decreases as the temperature increases. In this case, the correspondence between the temperature and the resistance value stored in the storage device (not shown) is as shown by the line L11 in FIG.

Instead of the above aspect, the temperature acquisition unit 13 may directly acquire the temperature of the electric heating type catalyst 200 based on the signal from the temperature sensor provided in the electric heating type catalyst 200. ..

The outside air temperature acquisition unit 14 is a part that performs a process of acquiring the ambient air temperature of the vehicle MV, that is, the outside air temperature. The outside air temperature acquisition unit 14 acquires the outside air temperature based on a signal from an outside air temperature sensor (not shown) provided in the vehicle MV. As such an outside air temperature sensor, for example, a thermistor provided in the middle of an intake pipe (not shown) for supplying air to the internal combustion engine 100 can be used. Instead of such an aspect, the outside air temperature acquisition unit 14 acquires, for example, weather information provided from an external server by wireless communication, and acquires the outside air temperature at the position of the vehicle MV based on the weather information. It may be that.

The abnormality determination unit 15 is a portion that performs processing for determining an abnormality in the power supply circuit. The "electric power supply circuit" is an electric circuit for supplying electric power for power generation to the electric heating type catalyst 200. The power supply circuit includes a drive circuit 16 described below, an electric wiring connecting the drive circuit 16 and the electrically heated catalyst 200, and the like. Further, in the electric heating type catalyst 200, a portion through which power for heat generation passes, that is, a base material 220 and an electrode 230 are also included in the power supply circuit.

The drive circuit 16 is a circuit provided for supplying electric power for heat generation to the electric heating type catalyst 200. As shown in FIG. 2, the drive circuit 16 includes a cutoff circuit 161, a switching circuit 162, and a battery 163.

The cutoff circuit 161 is a circuit for cutting off the supply of heat generation electric power to the electric heating type catalyst 200. When the electric power for heat generation is supplied to the electric heating type catalyst 200, the cutoff circuit 161 is closed. The operation of the cutoff circuit 161 is controlled by the power supply unit 12.

The switching circuit 162 is a circuit configured by a switching element (not shown), and switches the opening and closing of the power path connecting the battery 163 and the electrically heated catalyst 200. The operation of the switching circuit 162 is controlled by the power supply unit 12. The power supply unit 12 adjusts the magnitude of the heat generation power supplied to the electric heating type catalyst 200 by adjusting the duty in the opening / closing operation of the switching circuit 162.

The battery 163 is a power storage device that is a source of heat generation power, and is, for example, a lithium ion battery. As the battery 163, a battery for auxiliary equipment mounted on the vehicle MV is used. Instead of such an embodiment, the battery 163 may be provided as a dedicated power storage device for supplying electric power for heat generation to the electric heating type catalyst 200.

The drive circuit 16 of this embodiment is built in the control device 10. Instead of such an embodiment, the drive circuit 16 may be configured as a device separate from the control device 10 and may be arranged outside the control device 10.

The outline of the temperature control of the electric heating type catalyst 200 performed by the control device 10 will be described. FIG. 5A shows an example of a time change of the voltage value of the heat generating power supplied to the electrically heated catalyst 200. As described above, the power supply unit 12 adjusts the duty in the opening / closing operation of the switching circuit 162, thereby adjusting the magnitude of the heat generation power. In the example shown by the line L20 of FIG. 5A, the switching operation of the switching circuit 162 is repeated during the period from the time t10 to the time t13, and the electric heating power is supplied to the electric heating type catalyst 200.

FIG. 5B shows an example of a time change of the temperature of the electrically heated catalyst 200 acquired by the temperature acquisition unit 13. When the supply of the heating power to the electric heating type catalyst 200 is started at time t10, the temperature of the electric heating type catalyst 200 gradually rises as shown by the line L30 and the line L31. In the present embodiment, the target temperature T10 is set as a temperature equal to or higher than the active temperature of the electrically heated catalyst 200. The supply of heat generation power to the electric heating type catalyst 200 is basically continued until the temperature of the electric heating type catalyst 200 reaches the target temperature T10.

FIG. 5C shows an integrated value of the heat generation power supplied to the electrically heated catalyst 200, that is, an example of the time change of the electric energy. When the supply of heat-generating electric power to the electric heating catalyst 200 is started at time t10, the amount of electric power gradually increases as shown by the line L40 and the line L41. This amount of electric power can also be said to be the amount of heat generated in the electrically heated catalyst 200.

By the way, at the time of cold start of the vehicle MV, moisture may be attached to the inside of the electric heating type catalyst 200. Such moisture is, for example, dew condensation of the exhaust gas or the moisture contained in the air and adheres to the inner wall surface of the flow path 221 through which the exhaust gas passes in the electric heating type catalyst 200. The amount of water adhering to the inside of the electrically heated catalyst 200 varies depending on the length of time (soak time) elapsed until the internal combustion engine 100 is started, the temperature and humidity at that time, and the like.

The line L30 shown in FIG. 5B is an example of the temperature change of the electric heating type catalyst 200 when the supply of the electric power for heat generation is started in the state where the water content inside the electric heating type catalyst 200 is 0. Is shown. In this case, almost all of the energy of the electric power for power generation supplied to the electrically heated catalyst 200 is used for raising the temperature of the base material 220. Therefore, as shown by the line L30, the temperature of the electrically heated catalyst 200 rises at a relatively high rate after the time t10 when the supply of the power for heat generation is started.

Therefore, when the amount of water inside the electrically heated catalyst 200 is 0, it is preferable to set a relatively small value as the target amount of heat. E10 shown in FIG. 5C is an example of a target calorific value set as energy required to bring the temperature of the electrically heated catalyst 200 to T10 when the water content is 0. The line L40 in FIG. 5C is an example of the time change of the electric energy when E10 is set as the target calorific value. In this example, when the amount of electric power supplied to the electrically heated catalyst 200 reaches E10 at time t13, the supply of electric power for power generation is stopped at this point as shown by the line L20 in FIG. 5 (A). Will be done. Further, as shown by the line L30 in FIG. 5B, the temperature of the electrically heated catalyst 200 reaches the target temperature T10 at a timing substantially equal to this time t13.

The line L21 of FIG. 5A, the line L31 of FIG. 5B, and the line L41 of FIG. 5C all have a relatively large amount of water adhering to the inside of the electrically heated catalyst 200. An example is shown in the case where the heat generation power supply is started in the state.

In this case, a part of the energy of the electric power for power generation supplied to the electric heating type catalyst 200 is used for raising the temperature of the base material 220, while the other part is used for raising the temperature of the above-mentioned water and the temperature of the water. , Used as energy to evaporate water. Therefore, when the same E10 as in the previous example is set as the target calorific value, the temperature of the electrically heated catalyst 200 cannot reach the target temperature of T10.

Therefore, when a relatively large amount of water is attached to the inside of the electrically heated catalyst 200, it is preferable to set a relatively large value as the target calorific value. E11 shown in FIG. 5C is an example of a target calorific value set as energy required to bring the temperature of the electrically heated catalyst 200 to T10 when the water content is large.

When the amount of water contained in the electric heating catalyst 200 is large, as shown by the line L31 in FIG. 5B, when the power generation power supply is started at time t10, the electric heating catalyst is used. The temperature of 200 begins to rise. At a time t11 thereafter, when the temperature of the electrically heated catalyst 200 rises to, for example, about 100 ° C., the water adhering to the electrically heated catalyst 200 begins to boil. For some time from time t11, most of the energy of the supplied power for power generation is consumed as latent heat for boiling water. Therefore, in the period from the time t11 to the time t12 when the water content is completely evaporated, the temperature of the electrically heated catalyst 200 hardly rises.

After time t12, there is no water inside the electrically heated catalyst 200. Therefore, almost all of the energy of the electric power for power generation supplied to the electrically heated catalyst 200 is used for raising the temperature of the base material 220.

The supply of electric power for power generation is continued until the time t14 when the amount of electric power supplied to the electric heating type catalyst 200 reaches the target calorific value E11. When the amount of electric power supplied to the electric heating catalyst 200 reaches E11 at time t14, the supply of electric power for power generation is stopped at this point as shown by the line L21 in FIG. 5 (A). Further, as shown by the line L31 in FIG. 5B, the temperature of the electrically heated catalyst 200 reaches the target temperature T10 at a timing substantially equal to this time t14.

As described above, the energy required for the temperature of the electrically heated catalyst 200 to reach the target temperature T10, that is, the target calorific value, differs depending on the water content at that time. In other words, even when a certain target calorific value is set, the temperature reached by the electrically heated catalyst 200 when the power supply process is performed does not always reach the same temperature, and the water content at that time is used. The temperature will be different depending on the situation.

The abnormality determination unit 15 of the control device 10 according to the present embodiment utilizes the fact that the ultimate temperature of the electric heating type catalyst 200 when the electric power supply process is performed becomes a temperature different depending on the amount of water, and the electric power is obtained. It is determined whether or not there is an abnormality in the supply circuit.

An outline of a method for determining the presence or absence of an abnormality by the abnormality determination unit 15 will be described with reference to FIG.

FIG. 6A shows an example of the time change of the temperature of the electrically heated catalyst 200 acquired by the temperature acquisition unit 13 as in FIG. 5B. Similar to FIG. 5C, FIG. 6B shows an example of an integrated value of heat-generating electric power supplied to the electrically heated catalyst 200, that is, a time change of the electric energy.

When the humidity is low, for example, 0%, the amount of water adhering to the inside of the electrically heated catalyst 200 becomes almost zero. The lines L50 and L60 in FIG. 6 represent an example of a temperature change of the electrically heated catalyst 200 in such a case. In this example, in order to bring the temperature of the electrically heated catalyst 200 to the target temperature T10, a relatively small E _min is set as the target heat quantity.

On the other hand, when the humidity is high, for example, 100%, the amount of water adhering to the inside of the electrically heated catalyst 200 increases. Lines L52 and L62 of FIG. 6 represent an example of a temperature change of the electrically heated catalyst 200 in such a case. In this example, in order to bring the temperature of the electrically heated catalyst 200 to the target temperature T10, a relatively large E _max is set as the target heat quantity.

The lines L51 and L61 in FIG. 6 represent, for reference, an example of a temperature change of the electric heating type catalyst 200 when the amount of water adhering to the inside of the electric heating type catalyst 200 is medium. Is. In this example, in order to bring the temperature of the electrically heated catalyst 200 to the target temperature T10, an E _mid that is larger than E _min and smaller than E _max is set as the target calorific value.

As shown in FIG. 6, as the amount of water adhering to the electrically heated catalyst 200 increases, the value of the target amount of heat required to reach the target temperature T10 increases. E _max shown in FIG. 6B is necessary for the temperature of the electric heating catalyst 200 to reach the target temperature T10 when the amount of water adhering to the inside of the electric heating catalyst 200 is the largest. It can be said that the target amount of heat is.

Here, in a situation where the actual amount of water adhering to the inside of the electrically heated catalyst 200 is unknown, it is assumed that the humidity is 100%, the target heat amount is set to E _max , and then the power supply process is performed. Consider the case where In this case, the ultimate temperature of the electrically heated catalyst 200 when the power supply process is performed should be T10 or higher. The reason is that the actual amount of water adhering to the inside of the electrically heated catalyst 200 is equal to or equal to the amount of water in a situation where the target heat amount should be set to the maximum E _max (humidity 100% in this example). It should be less than that.

Therefore, if the temperature reached by the electric heating catalyst 200 does not reach T10 or higher and falls significantly below T10, some abnormality has occurred in the power supply circuit and heat is generated for the electric heating catalyst 200. It is presumed that the power supply was not performed normally.

Therefore, in the control device 10 according to the present embodiment, as shown in FIG. 6A, the threshold temperature T _th1 lower than T10 is set, the target heat quantity is set to E _max , and then the power supply process is performed. When the temperature reached by the electrically heated catalyst 200 at the time of failure is lower than the threshold temperature T _th1 , the abnormality determination unit 15 determines that an abnormality has occurred in the power supply circuit. The target calorific value set here is not set as the calorific value for accurately reaching the target temperature T10 for the temperature of the electric heating type catalyst 200, but is set as the calorific value for determining the abnormality of the power supply circuit. Is to be done.

The "reached temperature of the electric heating type catalyst 200 when the power supply processing is performed" is the target calorific value immediately after the power supply processing is completed, that is, the integrated value of the heat generation power supplied to the electric heating catalyst. It is the arrival temperature of the electric heating type catalyst 200 at the timing immediately after reaching.

A specific flow of processing performed for such abnormality determination will be described. The series of processes shown in FIG. 7 is started by the control device 10 at an arbitrary timing during the period in which the internal combustion engine 100 is operating.

In the first step S01 of the process, it is determined whether or not the internal combustion engine 100 has stopped. The operating state of the internal combustion engine 100 can be acquired by communication from, for example, a higher-level ECU (not shown) that controls the internal combustion engine 100. When the internal combustion engine 100 is not stopped and is in operation, the process of step S01 is executed again. When the internal combustion engine 100 is stopped, the process proceeds to step S02.

In step S02, the soak time _ts is updated. The soak time t _s is the length of the period during which the internal combustion engine 100 has been stopped. At a time point before the processing of FIG. 7 is started, the initial value of ts is set to ₀ . In step _S02 , the value of the soak time ts is updated based on the following equation (1).
t _s = t _s + Δt ... (1)

The second term “Δt” on the left side of the equation (1) is the time elapsed from the time when the process of step S02 was performed last time to the time when the process is performed this time.

In step S03 following step S02, it is determined whether or not the electric heating type catalyst 200 is energized, that is, whether or not the supply of heat generation power is started. For example, when the power supply unit 12 starts supplying the heat generation power by a command from a higher-level ECU (not shown), it is determined as Yes in step S03. The control device 10 may start the supply of the heat generation power based on its own judgment without being based on the command from the host ECU.

If the electric heating catalyst 200 has not yet been energized in step S03, the processes after step S02 are executed again, and the value of the soak time _ts is updated. When the energization of the electrically heated catalyst 200 is started, the process proceeds to step S04. At the time of shifting to step _S04 , the value of the soak time ts is fixed. Further, from this point, the power supply process described above will be started. However, the value of the target amount of heat in the power supply process is undecided at this point.

In step S04, the process of acquiring the _Tamb , which is the outside air temperature, is performed by the outside air temperature acquisition unit 14. This _Tamb is the temperature around the vehicle MV at the time when the energization of the electrically heated catalyst 200 is started.

In step S05 following step S04, the heat quantity setting unit 11 performs a process of calculating E _max , which is a target calorific value, based on the outside air temperature _Tamb and the soak time _ts . This E _max sets the temperature of the electric heating catalyst 200 to the target temperature T10 when the amount of water adhering to the inside of the electric heating catalyst 200 is the largest, as in the example described with reference to FIG. It is the target amount of heat required to reach. "When the amount of water adhering to the inside of the electric heating catalyst 200 is the largest" is, for example, when the soak time _ts has elapsed while the humidity of the electric heating catalyst 200 is 100%. That is.

Specifically, in step S05, the humidity around the electrically heated catalyst 200 is 100%, and the temperature around the vehicle MV is _Tamb , during the soak time _ts . Assuming that the amount of water expected to be accumulated in the electric heating catalyst 200 is present inside the electric heating type catalyst 200, it is necessary for the electric heating type catalyst 200 in such a state to reach the target temperature T10. Energy is set as the target calorific value E _max .

The correspondence between the combination of T _amb and _ts and the set E _max may be obtained in advance by an experiment or the like and stored in a storage device (not shown) included in the control device 10. Expressing the correspondence by the function f ₁ (), E _max can be calculated based on the following equation (2).
E _max = f ₁ (T _amb , t _s ) ... (2)

After the value of the target calorific value E _max is set in step S05 and the process shown in FIG. 7 is completed, a series of processes shown in FIG. 8 is started. At this time, the supply of heat-generating power to the electrically heated catalyst 200, which was started in step S03 of FIG. 7, is still being continued.

_In step S11 of FIG. 8, a process of updating the value of Ein, which is the electric energy of the heat generating electric power supplied to the electric heating type catalyst 200, is performed. Before the processing of FIG. 8 is started, the initial value of E _in is set to 0. _In step S11, the value of Ein is updated based on the following equation (3).
E _in = E _in + P _in Δt ... (3)

The second term “ _Pin ” on the left side of the equation (3) is the value of the heat generation power supplied to the electrically heated catalyst 200 at present. “Δt” in the same paragraph is the time elapsed from the time when the process of step S11 was performed last time to the time when the process is performed this time.

In step S12 following step S11, it is determined whether or not the value of E _in is equal to or greater than the value of the target calorific value E _max set in step S05 of FIG. If the value of E _in is less than the value of E _max , the processing after step S11 is executed again. When the value of E _in is equal to or greater than the value of E _max , the process proceeds to step S13. In step S13, a process of stopping the supply of heat generation electric power to the electrically heated catalyst 200 is performed. As a result, the power supply process is completed.

In step S14 following step S13, the temperature acquisition unit 13 performs a process of acquiring the temperature of the electrically heated catalyst 200. The temperature of the electrically heated catalyst 200 acquired in step S14 is also referred to as “T _sen ” below.

In step S15 following step S14, it is determined whether or not the value of T _sen is lower than the threshold temperature T _th1 . As shown in FIG. 6A, this “ _Th1 ” is a threshold value set to a value lower than the target temperature T10 by a predetermined temperature. If the value of T _sen is lower than the threshold temperature T _th1 , the process proceeds to step S16.

As described above, when the temperature reached by the electrically heated catalyst 200 falls below _Thth1 , which is even lower than T10, some abnormality has occurred in the power supply circuit, and the electric heating catalyst 200 has a relative temperature. It is presumed that the power for heat generation was not supplied normally. Therefore, when the process proceeds to step S16, the abnormality determination unit 15 determines that an abnormality has occurred in the power supply circuit.

On the other hand, if the value of T _sen is equal to or higher than the threshold temperature T _th1 in step S15, the process proceeds to step S17. In this case, the abnormality determination unit 15 determines that the power supply circuit is normal.

As described above, the abnormality determination unit 15 of the control device 10 according to the present embodiment has the reached temperature ( _Tsen in this example) of the electric heating type catalyst 200 when the power supply process is performed, and a predetermined threshold temperature. It is configured to determine an abnormality in the power supply circuit based on the comparison with ( _Th1 ). This makes it possible to determine an abnormality in the power supply circuit.

The calorific value setting unit 11 of the control device 10 according to the present embodiment sets the target calorific value as the calorific value required for the electrically heated catalyst 200 containing a predetermined amount of water to reach a predetermined target temperature (T10). Set (E _max ).

The above-mentioned "predetermined amount" is a value ( _Tamb ) in which the humidity around the electrically heated catalyst 200 is 100% and the air temperature around the vehicle MV is acquired by the outside air temperature acquisition unit 14. In the state, it is the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ). As described above, the calorific value setting unit 11 determines the length of the period during which the internal combustion engine 100 has been stopped, that is, the soak time ( _{ts) and the air temperature (Tamb )} acquired by the outside air temperature acquisition unit 14. Based on this, the target calorific value (E _max ) is set.

The above "predetermined amount" can be said to be the maximum amount of water expected to be accumulated inside the electrically heated catalyst 200 during the soak time _ts . If the power supply circuit is normal without any abnormality, the temperature of the electrically heated catalyst 200 should be at least the target temperature T10 or higher when E _max is input as the target heat quantity, and FIG. 6 shows. It should never fall below T _th1 .

Therefore, the abnormality determination unit 15 determines that an abnormality has occurred in the power supply circuit when the temperature reached by the electric heating catalyst 200 when the power supply process is performed is lower than the threshold temperature T _th1 . By such a method, it is possible to accurately determine the presence or absence of an abnormality in the power supply circuit.

As described above, the above-mentioned "predetermined amount" when setting the target calorific value E _max means that the humidity around the electrically heated catalyst 200 is 100% and the air temperature around the vehicle MV is 100%. It is the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ) in the state of the value ( _Tamb ) acquired by the outside air temperature acquisition unit 14. That is, in the present embodiment, the amount of water accumulated in the electric heating catalyst 200 is set under the assumption that the humidity around the electric heating catalyst 200 is 100%, and the target calorific value is set on the premise of the setting. E _max and threshold temperature T _th1 are set.

However, the above humidity may be a value different from 100%. For example, under the assumption that the humidity around the electric heating catalyst 200 is a predetermined value or more (for example, 95% or more), the amount of water accumulated in the electric heating catalyst 200 is set, and on the premise of this setting, The target calorific value E _max and the threshold temperature T _th1 may be set. That is, the above-mentioned "predetermined amount" when setting the target calorific value E _max means that the humidity around the electrically heated catalyst 200 is equal to or higher than a predetermined value, and the temperature around the vehicle MV is the outside air temperature acquisition unit. It may be the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ) in the state of the value ( _Tamb ) obtained in 14.

In the present embodiment, in step S13 of FIG. 8, after the process of stopping the supply of the power for heat generation to the electric heating type catalyst 200 is performed, acquisition of T _sen (step S14 of the same figure) and based on T _sen . Abnormality determination (step S15 in the figure) is performed. Instead of such an aspect, the process of stopping the supply of the heat generating electric power to the electric heating type catalyst 200 may be performed after the abnormality determination.

The second embodiment will be described. In the following, the points different from the first embodiment will be mainly described, and the points common to the first embodiment will be omitted as appropriate.

In the present embodiment, the method of determining the presence or absence of an abnormality by the abnormality determination unit 15 is different from that of the first embodiment. The outline of the determination method in the present embodiment will be described again with reference to FIG.

As described above, as the amount of water adhering to the electrically heated catalyst 200 increases, the value of the target amount of heat required to reach the target temperature T10 increases. E _min shown in FIG. 6B is necessary to bring the temperature of the electric heating catalyst 200 to the target temperature T10 when the amount of water adhering to the inside of the electric heating catalyst 200 is the smallest. It can be said that the target amount of heat is.

Here, in a situation where the actual amount of water adhering to the inside of the electrically heated catalyst 200 is unknown, it is assumed that the humidity is 0%, the target heat amount is set to E _min , and then the power supply process is performed. Consider the case where In this case, the ultimate temperature of the electrically heated catalyst 200 when the power supply process is performed should be T10 or less. The reason is that the actual amount of water adhering to the inside of the electrically heated catalyst 200 is equal to or equal to the amount of water in a situation where the target heat amount should be set to the minimum E _min (humidity 0% in this example). It should be more than that.

Therefore, if the temperature reached by the electric heating catalyst 200 does not fall below T10 but greatly exceeds T10, some abnormality has occurred in the power supply circuit and heat is generated for the electric heating catalyst 200. It is presumed that the power supply was not performed normally.

Therefore, in the control device 10 according to the present embodiment, as shown in FIG. 6A, the threshold temperature T _th2 higher than T 10 is set, the target heat quantity is set to E _min , and then the power supply process is performed. When the temperature reached by the electrically heated catalyst 200 is higher than the threshold temperature T _th2 , the abnormality determination unit 15 determines that an abnormality has occurred in the power supply circuit. The target calorific value set here is not set as the calorific value for accurately reaching the target temperature T10 of the temperature of the electric heating type catalyst 200, but is set as the calorific value for determining the abnormality of the power supply circuit. Is to be done.

A specific flow of processing performed for such abnormality determination will be described. The series of processes shown in FIG. 9 is repeatedly executed by the control device 10 when the internal combustion engine 100 is operating. This process is executed in place of the series of processes shown in FIG. 7, and step S05 in FIG. 7 is replaced with step S21.

After the process of acquiring the _Tamb , which is the outside air temperature, is performed in step S04, the process proceeds to step S21 in the present embodiment. In step S21, the heat quantity setting unit 11 performs a process of calculating E _min , which is a target heat quantity, based on the outside air temperature _Tamb and the soak time _ts . Similar to the example described with reference to FIG. 6, this E _min sets the temperature of the electric heating catalyst 200 to the target temperature T10 when the amount of water adhering to the inside of the electric heating catalyst 200 is the smallest. It is the target amount of heat required to reach. “When the amount of water adhering to the inside of the electrically heating catalyst 200 is the smallest” is, for example, when the soak time ts has elapsed in a state where the humidity in the electroheating catalyst 200 is ₀ %. That is.

Specifically, in step S21, the humidity around the electrically heated catalyst 200 is ₀ %, and the temperature around the vehicle MV is _Tamb , during the soak time ts. Assuming that the amount of water expected to be accumulated in the electric heating catalyst 200 is present inside the electric heating type catalyst 200, it is necessary for the electric heating type catalyst 200 in such a state to reach the target temperature T10. Energy is set as the target calorific value E _min .

The correspondence between the combination of T _amb and _ts and the set E _min may be obtained in advance by an experiment or the like and stored in a storage device (not shown) included in the control device 10. Expressing the correspondence by the function f ₂ (), E _min can be calculated based on the following equation (4).
E _min = f ₂ (T _amb , t _s ) ... (4)

After the value of the target calorific value E _min is set in step S21 and the process shown in FIG. 9 is completed, a series of processes shown in FIG. 10 is started. At this time, the supply of heat-generating power to the electrically heated catalyst 200, which was started in step S03 of FIG. 9, is still continued. The series of processes shown in FIG. 10 is executed in place of the series of processes shown in FIG. 8, and steps S12 and S15 in FIG. 8 are replaced with steps S31 and S32, respectively. There is.

After the process of updating the value of Ein is performed _in step S11, the process proceeds to step S31 in the present embodiment. In step S31, it is determined whether or not the value of E _in is equal to or greater than the value of the target calorific value E _min set in step S21 of FIG. If the value of E _in is less than the value of E _min , the processing after step S11 is executed again. If the value of E _in is equal to or greater than the value of E _min , the process proceeds to step S13. At the time of shifting to step S13, the electric energy of the heat generating electric power supplied to the electric heating type catalyst 200, that is, the value of _Ein is fixed.

After the process of acquiring the temperature T _sen of the electrically heated catalyst 200 is performed in step S14, the process proceeds to step S32 in this embodiment. In step S32, it is determined whether or not the value of T _sen is higher than the threshold temperature T _th2 . As shown in FIG. 6A, this “T _th2 ” is a threshold value set to a value higher than the target temperature T10 by a predetermined temperature. If the value of T _sen is higher than the threshold temperature T _th2 , the process proceeds to step S16. In step S16, the abnormality determination unit 15 determines that an abnormality has occurred in the power supply circuit.

On the other hand, if the value of T _sen is equal to or less than the threshold temperature T _th1 in step S32, the process proceeds to step S17. In this case, the abnormality determination unit 15 determines that the power supply circuit is normal.

As described above, the abnormality determination unit 15 of the control device 10 according to the present embodiment also has the temperature reached by the electric heating type catalyst 200 (T _sen in this example) and the predetermined threshold temperature when the power supply process is performed. It is configured to determine an abnormality in the power supply circuit based on the comparison with ( _Th2 ). This makes it possible to determine an abnormality in the power supply circuit.

The calorific value setting unit 11 of the control device 10 according to the present embodiment also has a target calorific value as the calorific value required for the electrically heated catalyst 200 containing a predetermined amount of water to reach a predetermined target temperature (T10). Set (E _min ).

The above-mentioned "predetermined amount" is a value ( _Tamb ) in which the humidity around the electrically heated catalyst 200 is 0% and the air temperature around the vehicle MV is acquired by the outside air temperature acquisition unit 14. In the state, it is the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ). When 0% is set as the humidity value as in the present embodiment, this "predetermined amount" becomes 0. As described above, the calorific value setting unit 11 determines the length of the period during which the internal combustion engine 100 has been stopped, that is, the soak time ( _{ts) and the air temperature (Tamb )} acquired by the outside air temperature acquisition unit 14. Based on this, the target calorific value (E _min ) is set.

The above "predetermined amount" can be said to be the minimum amount of water expected to be accumulated inside the electrically heated catalyst 200 during the soak time _ts . If there is no abnormality in the power supply circuit and it is normal, the temperature of the electrically heated catalyst 200 should be at least the target temperature T10 or less when _Emin is input as the target heat quantity, and FIG. 6 shows. It should never exceed T _th2 .

Therefore, the abnormality determination unit 15 determines that an abnormality has occurred in the power supply circuit when the temperature reached by the electric heating catalyst 200 when the power supply process is performed is higher than the threshold temperature T _th2 . By such a method, it is possible to accurately determine the presence or absence of an abnormality in the power supply circuit.

As described above, the above-mentioned "predetermined amount" when setting the target calorific value E _min means that the humidity around the electrically heated catalyst 200 is 0% and the air temperature around the vehicle MV is 0%. It is the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ) in the state of the value ( _Tamb ) acquired by the outside air temperature acquisition unit 14. That is, in the present embodiment, the amount of water accumulated in the electric heating catalyst 200 is set under the assumption that the humidity around the electric heating catalyst 200 is 0%, and the target calorific value is set on the premise of the setting. E _min and the threshold temperature T _th 2 are set.

However, the above humidity may be a value different from 0%. For example, under the assumption that the humidity around the electric heating catalyst 200 is a predetermined value or less (for example, 5% or less), the amount of water accumulated in the electric heating catalyst 200 is set, and on the premise of this setting, The target calorific value E _min and the threshold temperature T _th 2 may be set. That is, the above-mentioned "predetermined amount" when setting the target calorific value E _min means that the humidity around the electrically heated catalyst 200 is equal to or less than a predetermined value, and the temperature around the vehicle MV is the outside air temperature acquisition unit. It may be the amount of water accumulated inside the electrically heated catalyst 200 during the soak time ( _ts ) in the state of the value ( _Tamb ) obtained in 14.

In the present embodiment, in step S13 of FIG. 10, after the process of stopping the supply of the power for heat generation to the electric heating type catalyst 200 is performed, acquisition of T _sen (step S14 of the same figure) and T _sen are used. Abnormality determination (step S32 in the figure) is performed. Instead of such an aspect, the process of stopping the supply of the heat generating electric power to the electric heating type catalyst 200 may be performed after the abnormality determination.

The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. These specific examples with appropriate design changes by those skilled in the art are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element provided in each of the above-mentioned specific examples, its arrangement, conditions, a shape, and the like are not limited to those exemplified, and can be appropriately changed. The combinations of the elements included in each of the above-mentioned specific examples can be appropriately changed as long as there is no technical contradiction.

The controls and methods described in this disclosure are dedicated to one or more provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. It may be realized by a computer. The control device and control method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor including one or more dedicated hardware logic circuits. The control device and control method described in the present disclosure comprises a combination of a processor and memory programmed to perform one or more functions and a processor including one or more hardware logic circuits. It may be realized by one or more dedicated computers. The computer program may be stored on a computer-readable non-transitional tangible recording medium as an instruction executed by the computer. The dedicated hardware logic circuit and the hardware logic circuit may be realized by a digital circuit including a plurality of logic circuits or an analog circuit.

10: Control device 11: Heat quantity setting unit 12: Power supply unit 13: Temperature acquisition unit 15: Abnormality determination unit 200: Electric heating type catalyst

Claims (7)

It is a control device (10) of an electric heating type catalyst (200), and is
The heat amount setting unit (11) that sets the target heat amount,
A power supply unit (12) that performs a power supply process, which is a process of supplying electric power for power generation to the electric heating type catalyst so that the set target heat amount is generated by the electric heating type catalyst.
A temperature acquisition unit (13) for acquiring the temperature of the electrically heated catalyst, and
The electric heating type catalyst is provided with an abnormality determination unit (15) for determining an abnormality in a power supply circuit for supplying electric power for power generation.
The abnormality determination unit is
A control device for determining an abnormality in the power supply circuit based on a comparison between the temperature reached by the electrically heated catalyst when the power supply process is performed and a predetermined threshold temperature. The calorific value setting unit is
The control device according to claim 1, wherein the target calorific value is set as the calorific value required for the electric heating catalyst containing a predetermined amount of water to reach a predetermined target temperature. The electrically heated catalyst is mounted on a vehicle (MV) having an internal combustion engine (100).
Further equipped with an outside air temperature acquisition unit (14) for acquiring the air temperature around the vehicle,
The calorific value setting unit is
The control device according to claim 2, wherein the target heat quantity is set based on the soak time, which is the length of the period during which the internal combustion engine has been stopped, and the temperature acquired by the outside air temperature acquisition unit. The predetermined amount is
The electric heating during the soak time in a state where the humidity around the electric heating catalyst is equal to or higher than a predetermined value and the temperature around the vehicle is the value acquired by the outside air temperature acquisition unit. Formula The amount of water accumulated inside the catalyst,
The abnormality determination unit is
The control device according to claim 3, wherein when the temperature reached by the electrically heated catalyst when the power supply process is performed is lower than the threshold temperature, it is determined that an abnormality has occurred in the power supply circuit. .. The control device according to claim 4, wherein the predetermined value is 100%. The predetermined amount is
The electric heating during the soak time in a state where the humidity around the electric heating catalyst is equal to or less than a predetermined value and the temperature around the vehicle is the value acquired by the outside air temperature acquisition unit. Formula The amount of water accumulated inside the catalyst,
The abnormality determination unit is
The control device according to claim 3, wherein when the temperature reached by the electrically heated catalyst when the power supply process is performed is higher than the threshold temperature, it is determined that an abnormality has occurred in the power supply circuit. .. The control device according to claim 6, wherein the predetermined value is 0%.

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