JP2021084462A - On-vehicle device and catalyst heating control method - Google Patents

Abstract

To ensure emission purification performance while curbing waste of power.SOLUTION: An on-vehicle device is mounted on a vehicle which has an internal combustion engine and an electric motor and travels using at least either the internal combustion engine or the electric motor as a power source. The on-vehicle device has an acquisition section, a calculation section, and a setting section. The acquisition section acquires a situation of the vehicle. The calculation section calculates a probability of start-up of the internal combustion engine on the basis of the situation acquired through the acquisition section. The setting section sets a target temperature of a catalyst installed in an exhaust passage of the internal combustion engine on the basis of the probability of start-up calculated by the calculation section so that the catalyst is preheated to the target temperature.SELECTED DRAWING: Figure 2

Description

The disclosed embodiments relate to in-vehicle devices and catalyst heating control methods.

Conventionally, in a vehicle equipped with an engine, the catalyst provided in the exhaust path of the engine is preheated by an in-vehicle power source immediately after the ignition (IG) is turned on and activated at an early stage to improve the emission purification performance. A heating catalyst (EHC: Electrically Heated Catalyst) is known.

Such an EHC is also installed in an HEV (Hybrid Electric Vehicle) or a range extender EV (Electric Vehicle) equipped with a motor and an engine, but in the case of a vehicle that can use such a motor as a power source, exhaust is not required only by running the motor. The running may end as it is, and in such a case, the power used for the above-mentioned preheating is wasted.

Therefore, when the mileage of the motor after the IG is turned on, which is calculated from SOC (State Of Charge), etc., is larger than the mileage to the destination, preheating of the EHC is prohibited to waste power. Techniques to suppress it have been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-120333

However, there is room for further improvement in the prior art in ensuring the emission purification performance while suppressing the waste of electric power. For example, in the prior art, it is not possible to preheat the EHC in a situation where an unexpected engine start is performed, such as when the user suddenly accelerates within the mileage of the motor. Therefore, in such a case, there is a problem that the emission purification performance is deteriorated.

One aspect of the embodiment is made in view of the above, and an object of the present invention is to provide an in-vehicle device and a catalyst heating control method capable of ensuring emission purification performance while suppressing waste of electric power.

The in-vehicle device according to one aspect of the embodiment is an in-vehicle device having an internal combustion engine and an electric motor and mounted on a vehicle traveling by using at least one of the internal combustion engine and the electric motor as a power source. It includes a calculation unit and a setting unit. The acquisition unit acquires the status of the vehicle. The calculation unit calculates the start probability of the internal combustion engine based on the situation acquired by the acquisition unit. The setting unit sets a target temperature of the catalyst provided in the exhaust path of the internal combustion engine based on the starting probability calculated by the calculation unit, and preheats the catalyst so as to reach the target temperature.

According to one aspect of the embodiment, it is possible to secure the emission purification performance while suppressing the waste of electric power.

FIG. 1A is a schematic explanatory view of a catalyst heating control method according to a comparative example. FIG. 1B is a schematic explanatory view of the catalyst heating control method according to the embodiment. FIG. 2 is a block diagram showing a configuration example of the catalyst heating control system according to the embodiment. FIG. 3 is an explanatory diagram of the probability model according to the embodiment. FIG. 4 is an explanatory diagram of target temperature information according to the embodiment. FIG. 5 is an operation explanatory view of the catalyst heating control system according to the embodiment. FIG. 6 is a flowchart showing a processing procedure executed by the in-vehicle device according to the embodiment.

Hereinafter, embodiments of the in-vehicle device and the catalyst heating control method disclosed in the present application will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments shown below.

Further, in the following, the case where the in-vehicle device 10 according to the embodiment is mounted on a vehicle having an engine and a motor such as an HEV and a range extender EV and traveling by using at least one of the engine and the motor as a power source is an example. The explanation will be given in.

First, the outline of the catalyst heating control method according to the embodiment will be described with reference to FIGS. 1A and 1B. FIG. 1A is a schematic explanatory view of a catalyst heating control method according to a comparative example. Further, FIG. 1B is a schematic explanatory view of the catalyst heating control method according to the embodiment.

As shown in FIG. 1A, in the catalyst heating control method according to the comparative example, for example, the EHC heater is turned on immediately after the IG is turned on, and the catalyst is quickly preheated to a predetermined active temperature. However, in the case of such a method, as shown in FIG. 1A, if the running is completed only by the motor running without starting the engine, the electric power used for preheating the catalyst is wasted.

On the other hand, when the mileage of the motor after the IG is turned on, which is calculated from the SOC, etc., is larger than the mileage to the destination, preheating of the EHC is prohibited to reduce the waste of electric power. There is a way to do it.

However, in the case of such a method, the EHC cannot be preheated in a situation where the engine is unexpectedly started, such as when the user suddenly accelerates within the mileage of the motor. Therefore, in such a case, the exhaust gas is discharged through the catalyst that has not reached the predetermined active temperature, and the emission purification performance is deteriorated.

Therefore, in the catalyst heating control method according to the embodiment, the vehicle condition is acquired, the engine start probability is calculated based on the acquired condition, and the engine exhaust path is provided based on the calculated start probability. The target temperature of the catalyst was set, and the catalyst was preheated to reach such a target temperature.

Specifically, as shown in FIG. 1B, in the catalyst heating control system 1 to which the catalyst heating control method according to the embodiment is applied, the in-vehicle device 10 acquires the vehicle status (step S1).

The in-vehicle device 10 includes, for example, a car navigation device having a camera, various sensors such as an acceleration sensor, a steering angle sensor, a gyro sensor, a GPS (Global Positioning System) sensor, a storage device, a microcomputer, and an ECU (Electronic Control Unit). And so on.

The situation acquired by the in-vehicle device 10 includes both a static situation and a dynamic situation inside and outside the vehicle, and for example, as shown in FIG. 1B, the number of occupants and the driving habit of the driver. Includes various situations such as shift changes and uphills. It should be noted that these may be rephrased as various characteristics related to the vehicle.

Then, the in-vehicle device 10 calculates the engine start probability based on these various acquired situations (step S2). In the calculation, the in-vehicle device 10 uses a probabilistic model generated in advance by using a machine learning algorithm such as deep learning. Such a probabilistic model will be described later with reference to FIG.

Then, the in-vehicle device 10 sets the target temperature of the heater that preheats the catalyst according to the calculated probability (step S3). For example, if the calculated probability is 20%, the in-vehicle device 10 sets a target temperature according to the calculated probability of 20%. Further, for example, if the calculated probability is 40%, the in-vehicle device 10 sets a target temperature corresponding to the 20%, for example, a target temperature higher than when the probability is 20%.

Such setting of the target temperature is performed, for example, based on the map information in which the engine start probability and the target temperature are associated with each other. Such map information will be described later with reference to FIG.

Then, the in-vehicle device 10 preheats the catalyst so as to reach the set target temperature. The series of operations of steps S1 to S3 are repeated from moment to moment according to the condition of the vehicle acquired, and the target temperature of the heater is updated as appropriate. An operation example of such a catalyst heating control system 1 will be described later with reference to FIG.

As described above, in the catalyst heating control method according to the embodiment, the in-vehicle device 10 acquires the vehicle condition, calculates the engine start probability based on the acquired condition, and based on the calculated start probability, the engine. It was decided to set a target temperature of the catalyst provided in the exhaust path of the above and preheat the catalyst so as to reach such a target temperature.

Therefore, according to the catalyst heating control method according to the embodiment, the catalyst can be preheated at an appropriate target temperature according to the engine start probability estimated from various acquired situations. For example, when the engine reaches an uphill and the required torque is predicted to increase, the engine start probability can be increased, and the catalyst can be preheated at a target temperature corresponding to this.

That is, according to the catalyst heating control method according to the embodiment, it is possible to secure the emission purification performance while suppressing the waste of electric power.

Hereinafter, a configuration example of the catalyst heating control system 1 to which the catalyst heating control method according to the above-described embodiment is applied will be described more specifically.

FIG. 2 is a block diagram showing a configuration example of the catalyst heating control system 1 according to the embodiment. Note that FIG. 2 shows only the components necessary for explaining the features of the present embodiment, and the description of general components is omitted.

In other words, each component shown in FIG. 2 is a functional concept and does not necessarily have to be physically configured as shown in the figure. For example, the specific form of distribution / integration of each block is not limited to the one shown in the figure, and all or part of it may be functionally or physically distributed in arbitrary units according to various loads and usage conditions. It can be integrated and configured.

Further, in the description using FIG. 2, the description of the components already described may be simplified or omitted.

As shown in FIG. 2, the catalyst heating control system 1 according to the embodiment includes an in-vehicle device 10, various sensors 20, and an EHC 30. As described above, the in-vehicle device 10 is configured as, for example, a car navigation device, an ECU, or the like.

The various sensors 20 correspond to the above-mentioned cameras, acceleration sensors, steering angle sensors, gyro sensors, GPS sensors, etc., and are communicably connected to the in-vehicle device 10.

The EHC 30 is provided in the exhaust path of the engine and is communicably connected to the in-vehicle device 10. The EHC 30 includes a control device 31, a heater 32, and a catalyst 33. The control device 31 heats and controls the heater 32 according to the target temperature set by the in-vehicle device 10. The heater 32 electrically heats the catalyst 33 under the control of the control device 31. The catalyst 33 is a so-called three-way catalyst.

The various sensors 20 and the EHC 30 are connected to the in-vehicle device 10 via, for example, a CAN (Controller Area Network) bus. It may be connected so that communication can be performed by a protocol other than CAN. Moreover, it may be in a wireless form.

The in-vehicle device 10 includes a storage unit 11 and a control unit 12. The storage unit 11 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory (Flash Memory), or a storage device such as a hard disk or an optical disk. The probability model 11b and the target temperature information 11c are stored.

The characteristic information 11a is information on various characteristics related to the vehicle, and mainly includes static information among such characteristics. For example, the characteristic information 11a includes information on user characteristics, and the information on such user characteristics includes various parameters indicating the gender, age, driving history, and driving habit of the driver of the vehicle.

Further, the characteristic information 11a includes, for example, information on vehicle characteristics, and the information on such vehicle characteristics includes a vehicle type, a vehicle body shape, and the like. Further, the characteristic information 11a includes, for example, information on the route characteristic, and the information on the route characteristic includes map information such as a dynamic map, route information set by the user, and the like.

The probability model 11b is a probability calculation model that outputs the engine start probability by inputting the characteristic information 11a and various static and dynamic situations acquired from the various sensors 20 by the acquisition unit 12a described later. As described above, the probability model 11b is generated in advance using a machine learning algorithm such as deep learning and stored in the storage unit 11.

Here, the probability model 11b will be described more specifically with reference to FIG. FIG. 3 is an explanatory diagram of the probability model 11b according to the embodiment.

As shown in FIG. 3, the probability model 11b is generated as a probability calculation model that outputs the engine start probability by inputting various characteristics related to the vehicle. As shown in FIG. 3 as an autoencoder of the probability model 11b, deep learning is used as a machine learning algorithm when generating the probability model 11b. Since deep learning is known, detailed description here will be omitted.

For example, the probabilistic model 11b executes machine learning based on each data indicating various situations of the vehicle collected as learning data, in other words, each data indicating various characteristics related to the vehicle at the time of learning, and each of these data is used. Generated to function as a function that outputs the engine start probability when input.

As shown in FIG. 3, each data showing various characteristics related to the vehicle is, for example, each element showing user characteristics, vehicle characteristics, route characteristics, environmental characteristics, etc., and can be either static information or dynamic information. Also includes.

For example, each element indicating user characteristics includes various parameters related to the number of occupants, driving habits, and the like. Further, for example, each element indicating the vehicle characteristics includes various parameters related to the vehicle type, SOC, and the like. In addition to this, various parameters related to the degree of tire wear, the status of shift change, the total mileage, and the like may be included.

Further, for example, each element indicating the route characteristic includes various parameters related to a slope, a curve, a traffic jam condition, etc. on the traveling route. Further, for example, each element indicating the environmental characteristics includes various parameters related to the weather and the like.

The probability model 11b is generated in a server environment of a data center or the like at the time of development of the in-vehicle device 10, and is pre-installed and used before the in-vehicle device 10 is shipped. In addition, during the operation of the in-vehicle device 10, the in-vehicle device 10 itself may perform additional learning based on various data acquired moment by moment, and the probability model 11b may be updated as appropriate.

In addition, various data acquired by the in-vehicle device 10 in operation are collected at any time on the data center side, additional learning is performed on the data center side based on the collected data, and the updated probability model 11b is obtained by the in-vehicle device 10. It may be delivered to as appropriate.

Returning to the description of FIG. The target temperature information 11c is map information in which the engine start probability and the target temperature are associated with each other. Here, the target temperature information 11c will be described more specifically with reference to FIG. FIG. 4 is an explanatory diagram of the target temperature information 11c according to the embodiment.

As shown in FIG. 4, the target temperature information 11c is map information in which the engine start probability and the target temperature are associated with each other. The target temperature information 11c is generated in advance based on, for example, verification results by simulations, experiments, etc. at the time of development of the in-vehicle device 10. As with the probability model 11b, it may be generated by executing machine learning.

Further, the target temperature information 11c may be provided for each type of the catalyst 33, for example. As a result, for example, preheating can be performed according to each catalyst 33 having a different activity temperature, and the emission purification performance can be ensured with high accuracy.

Returning to the description of FIG. The control unit 12 is a controller, and for example, various programs stored in a storage device inside the in-vehicle device 10 by a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or the like use the RAM as a work area. It is realized by being executed. Further, the control unit 12 can be realized by, for example, an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

The control unit 12 has an acquisition unit 12a, a calculation unit 12b, and a setting unit 12c, and realizes or executes an information processing function or operation described below.

The acquisition unit 12a receives output data from various sensors 20 and acquires dynamic conditions inside and outside the vehicle that change from moment to moment based on the output data.

For example, the acquisition unit 12a acquires the number of occupants based on the image captured by the camera. Further, for example, the acquisition unit 12a acquires the current position of the vehicle based on the GPS sensor. Further, for example, the acquisition unit 12a acquires the traveling state of the vehicle based on the acceleration sensor, the steering angle sensor, and the gyro sensor. Further, the acquisition unit 12a mainly acquires a static situation based on the characteristic information 11a.

The calculation unit 12b calculates the engine start probability by using the probability model 11b based on the situation acquired by the acquisition unit 12a. Further, the calculation unit 12b notifies the setting unit 12c of the calculated start probability.

The setting unit 12c sets the target temperature in the EHC based on the start probability and the target temperature information 11c calculated by the calculation unit 12b. Further, the setting unit 12c notifies the control device 31 of the set target temperature, and causes the control device 31 to heat-control the heater 32 so that the catalyst floor temperature of the catalyst 33 becomes the target temperature.

In the example of FIG. 2, the control device 31 controls the heating of the heater 32, but the setting unit 12c may directly control the heating of the heater 32 without using the control device 31.

Here, a specific operation example of the catalyst heating control system 1 will be described with reference to FIG. FIG. 5 is an operation explanatory view of the catalyst heating control system 1 according to the embodiment.

As shown in FIG. 5, it is assumed that the shift change is performed from "P" to "D" after the IG is turned on, for example, at the timing t1. In such a case, the in-vehicle device 10 calculates, for example, 20% as the engine start probability.

Then, the target temperature is set to, for example, 100 ° C. according to this, and the in-vehicle device 10 sets the EHC 30 so that the catalyst bed temperature becomes 100 ° C., in other words, the catalyst bed temperature follows the target temperature. The catalyst 33 is preheated.

Further, it is assumed that the uphill is reached at timing t2, for example. Since such a situation is a situation in which the torque required by the user is estimated to be large, the in-vehicle device 10 calculates 40%, which is larger than, for example, 20%, as the engine start probability.

Then, the target temperature is set to, for example, 200 ° C. according to this, and the in-vehicle device 10 causes the EHC 30 to preheat the catalyst 33 so that the catalyst floor temperature becomes 200 ° C.

Further, it is assumed that the signal is stopped at the timing t3, for example. In such a situation, it is estimated that the torque required by the user at the time of starting is further increased. Therefore, the in-vehicle device 10 calculates 60%, which is larger than, for example, 40%, as the starting probability of the engine.

Then, the target temperature is set to, for example, 300 ° C. according to this, and the in-vehicle device 10 causes the EHC 30 to preheat the catalyst 33 so that the catalyst floor temperature becomes 300 ° C.

In this way, by controlling the target temperature to be higher as the probability is higher, depending on the engine start probability, the emission purification performance is compared to the case where an unexpected engine start is performed without preheating, for example. (See "Emissions" in Fig. 5).

Further, as compared with the case of the comparative example (see FIG. 1A) in which the heater 32 of the EHC 30 is turned on immediately after the IG is turned on, it is possible to suppress the waste of electric power (see “Integrated power consumption” in FIG. 5).

Next, the processing procedure executed by the in-vehicle device 10 according to the embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing a processing procedure executed by the in-vehicle device 10 according to the embodiment. Note that FIG. 6 shows a processing procedure for setting the target temperature once. In reality, such a processing procedure will be repeated from moment to moment.

As shown in FIG. 6, first, the acquisition unit 12a acquires the vehicle status from the various sensors 20 and the characteristic information 11a (step S101). Then, the calculation unit 12b calculates the engine start probability using the probability model 11b based on the situation acquired by the acquisition unit 12a (step S102).

Then, the setting unit 12c sets the target temperature of the catalyst 33 based on the start probability calculated by the calculation unit 12b (step S103). Then, the setting unit 12c preheats the catalyst 33 so as to reach the set target temperature (step S104), and ends the process for setting the target temperature once.

As described above, the vehicle-mounted device 10 according to the embodiment has an engine (corresponding to an example of an "internal combustion engine") and a motor (corresponding to an example of an "electric motor"), and at least one of such an engine and a motor. It is an in-vehicle device mounted on a vehicle traveling as a power source, and includes an acquisition unit 12a, a calculation unit 12b, and a setting unit 12c. The acquisition unit 12a acquires the status of the vehicle. The calculation unit 12b calculates the engine start probability based on the situation acquired by the acquisition unit 12a. The setting unit 12c sets a target temperature of the catalyst 33 provided in the exhaust path of the engine based on the starting probability calculated by the calculation unit 12b, and preheats the catalyst 33 so as to reach such a target temperature.

Therefore, according to the in-vehicle device 10 according to the embodiment, it is possible to secure the emission purification performance while suppressing the waste of electric power.

Further, the setting unit 12c sets the target temperature so that the higher the engine start probability is, the higher the target temperature is.

Therefore, according to the in-vehicle device 10 according to the embodiment, if the engine start probability is high, the target temperature can be set so that the emission purification performance is ensured accordingly.

Further, the calculation unit 12b calculates the engine start probability using the probability model 11b generated by executing machine learning using each element indicating the vehicle condition.

Therefore, according to the in-vehicle device 10 according to the embodiment, it is possible to calculate the engine start probability with high accuracy according to the situation of the vehicle while using the probability model 11b.

In addition, each element indicating the situation of the vehicle includes parameters relating to at least one of user characteristics, vehicle characteristics, route characteristics, and environmental characteristics.

Therefore, according to the in-vehicle device 10 according to the embodiment, it is possible to calculate the engine start probability with high accuracy based on various parameters that affect the behavior of the vehicle.

In addition, the above parameters relate to at least one of the number of occupants, driving habits, traveling routes, traffic conditions, acceleration and shift positions.

Therefore, according to the in-vehicle device 10 according to the embodiment, it is possible to calculate the engine start probability with high accuracy based on at least one of the number of occupants, driving habit, traveling route, traffic jam condition, acceleration and shift position. can do.

Further, the setting unit 12c sets the target temperature according to the type based on the target temperature information 11c provided for each type of the catalyst 33.

Therefore, according to the in-vehicle device 10 according to the embodiment, for example, preheating can be performed according to each catalyst 33 having a different activity temperature, and the emission purification performance can be ensured with high accuracy.

In the above-described embodiment, deep learning is used as the machine learning algorithm, but the algorithm used is not limited. Therefore, machine learning may be executed by a regression analysis method such as support vector regression using a pattern classifier such as SVM (Support Vector Machine) to generate a probability model 11b. Further, here, the pattern classifier is not limited to the SVM, and may be, for example, AdaBoost. Moreover, you may use a random forest or the like.

Further effects and variations can be easily derived by those skilled in the art. For this reason, the broader aspects of the invention are not limited to the particular details and representative embodiments expressed and described as described above. Therefore, various modifications can be made without departing from the spirit or scope of the general concept of the invention as defined by the appended claims and their equivalents.

1 Catalyst heating control system 10 In-vehicle device 11 Storage unit 11a Characteristic information 11b Probability model 11c Target temperature information 12 Control unit 12a Acquisition unit 12b Calculation unit 12c Setting unit 20 Various sensors 30 EHC
31 Control device 32 Heater 33 Catalyst

Claims (7)

An in-vehicle device having an internal combustion engine and an electric motor and mounted on a vehicle traveling by using at least one of the internal combustion engine and the electric motor as a power source.
The acquisition unit that acquires the status of the vehicle and
A calculation unit that calculates the start probability of the internal combustion engine based on the situation acquired by the acquisition unit, and
Based on the start probability calculated by the calculation unit, the target temperature of the catalyst provided in the exhaust path of the internal combustion engine is set, and the setting unit for preheating the catalyst to reach the target temperature is provided. In-vehicle device as a feature. The setting unit
The vehicle-mounted device according to claim 1, wherein the target temperature is set so that the higher the starting probability is, the higher the target temperature is. The calculation unit
The vehicle-mounted device according to claim 1 or 2, wherein the starting probability is calculated using a probability model generated by executing machine learning using each element indicating the situation of the vehicle. Each element indicating the condition of the vehicle is
The vehicle-mounted device according to claim 3, further comprising parameters relating to at least one of user characteristics, vehicle characteristics, route characteristics, and environmental characteristics. The parameters are
The vehicle-mounted device according to claim 4, wherein the vehicle-mounted device is characterized by at least one of a number of occupants, a driving habit, a traveling route, a traffic jam condition, an acceleration and a shift position. The setting unit
The vehicle-mounted device according to any one of claims 1 to 5, wherein the target temperature is set according to the type based on the target temperature information provided for each type of the catalyst. A catalyst heating control method using an in-vehicle device having an internal combustion engine and an electric motor and mounted on a vehicle traveling by using at least one of the internal combustion engine and the electric motor as a power source.
The acquisition process to acquire the status of the vehicle and
A calculation step of calculating the start probability of the internal combustion engine based on the situation acquired in the acquisition process, and
Based on the start probability calculated in the calculation step, the target temperature of the catalyst provided in the exhaust path of the internal combustion engine is set, and the setting step of preheating the catalyst to reach the target temperature is included. A characteristic catalyst heating control method.

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