CONTROL DEVICE, CONTROL METHOD AND MOTOR SYSTEM

Abstract

A control device is a control device of an engine system including an engine, an oxidation catalyst provided in an exhaust passage of the engine, and a filter configured to collect soot in the exhaust passage, the soot being contained in the exhaust gas of the engine, the control device including: an ash accumulation amount estimation unit configured to estimate an amount of ash accumulated in the filter; and a regeneration control unit configured to control regeneration of the filter when the amount of ash is equal to or less than a predetermined threshold so that a predetermined amount of soot remains in the filter, and to control regeneration of the filter when the amount of ash is greater than the threshold so that the remaining amount of soot in the filter is less than the predetermined amount.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a control apparatus, a control method, and an engine system.

[0002] This application claims priority based on Japanese Patent Application No. 2023-004425, filed in Japan on January 16, 2023, the contents of which are hereby incorporated by reference. STATE OF THE ART

[0003] As described in PTL 1, it has been found that in a diesel particulate filter (hereinafter referred to as "DPF") that collects particulate matter (PM) contained in the exhaust gas of a diesel engine, the soot collection efficiency improves when a certain amount of soot accumulates (paragraph

[0009] of PTL 1). Therefore, the soot collection efficiency may deteriorate immediately after the regeneration process for burning and removing the soot accumulated in the DPF (hereinafter referred to as "regeneration"). In view of this, in the exhaust gas purification device described in PTL 1, regeneration is terminated while an appropriate amount of soot remains. This suppresses deterioration of the soot collection performance immediately after regeneration.

[0004] Furthermore, NPTL 1 and NPTL 2 describe the following technical matters. NPTL 1 describes, for example, that the collection efficiency of the DPF is improved when a soot layer forms on a partition wall surface of the DPF. Furthermore, NPTL 2 describes, for example, that an ash layer formed on the DPF prevents soot from penetrating to the other side of the wall.

[0005] However, the particulate matter (hereinafter referred to as "PM") contained in the exhaust gas of a diesel engine includes soot, ash, and the like. Soot is carbon emitted by an engine and accumulates in a DPF installed downstream of the engine. The soot accumulated in the DPF reacts with nitrogen dioxide or oxygen during regeneration and is removed from the DPF. Ash, on the other hand, is an ash component contained in engine oil and accumulates in the DPF when traces of oil burn in a combustion chamber. Even regeneration does not remove the ash and remains in the DPF. Furthermore, the ash continues to accumulate during engine operation. LITERATURE LISTPatent literature

[0006] PTL 1: JP 2005-307746 A Non-patent literature NPTL 1: Koji Tsuneyoshi, Osamu Takagi und Kazuhiro Yamamoto, „Effect of Surface Roughness on Initial PM Filtration Efficiency of DPF“, Transactions of the Japan Society of Mechanical Engineers, Series B, The Japan Society of Mechanical Engineers, Bd. 76, Nr. 767, 25. Juli, 2010, S. 100-107 (S. 1110-1117) NPTL 2: Akira Usui, Toru Uenishi, Takao Fukuma und Hitoshi Kusaka, „Evaluation of Diesel Particulate Filter with Ash Deposit“, Transactions of the Society of Automotive Engineers of Japan, Inc., Society of Automotive Engineers of Japan, Bd. 49, Nr. 4, Juli 2018, S. 690-695 KURZDARSTELLUNG DER ERFINDUNGTechnisches Problem

[0007] As described above, in the exhaust gas purification device described in Patent Application Publication 1, regeneration is terminated while a predetermined amount of soot remains. However, if a predetermined amount of soot remains and the remaining amount is increased, there is a possibility that the time until the next regeneration is required may be shortened depending on the operating conditions or the like. In this regard, it is desirable that the remaining soot remain as little as possible after the regeneration process is completed.

[0008] The present disclosure has been made in view of the above circumstances and has an object to provide a control apparatus, a control method and an engine system that can reduce the amount of soot remaining after completion of regeneration. Solution to the problem

[0009] One aspect of the present disclosure is a control device of an engine system including an engine, an oxidation catalyst provided in an exhaust passage of the engine, and a filter configured to collect soot in the exhaust passage, the soot being contained in exhaust gas of the engine, the control device including: an ash accumulation amount estimation unit configured to estimate an amount of ash accumulated in the filter, and a regeneration control unit configured to control regeneration of the filter when the amount of ash is equal to or less than a predetermined threshold so that a predetermined amount of soot remains in the filter, and to control regeneration of the filter when the amount of ash is greater than the threshold so that the remaining amount of soot in the filter is less than the predetermined amount.

[0010] One aspect of the present disclosure is a control method of an engine system including an engine, an oxidation catalyst provided in an exhaust passage of the engine, and a filter that collects soot in the exhaust passage, the soot being contained in exhaust gas of the engine, the control method including: estimating an amount of ash accumulated in the filter; and controlling regeneration of the filter when the amount of ash is equal to or less than a predetermined threshold so that a predetermined amount of soot remains in the filter; and controlling regeneration of the filter when the amount of ash is greater than the threshold so that the remaining amount of soot in the filter is less than the predetermined amount.

[0011] One aspect of the present disclosure is an engine system including an engine, an oxidation catalyst provided in an exhaust passage of the engine, a filter configured to collect soot in the exhaust passage, the soot contained in the exhaust gas of the engine, and a control device configured to control regeneration of the filter. The control device includes: an ash accumulation amount estimation unit configured to estimate an amount of ash accumulated in the filter; and a regeneration control unit configured to, when the amount of ash is equal to or less than a predetermined threshold, control regeneration of the filter so that a predetermined amount of soot remains in the filter, and when the amount of ash is greater than the threshold, control regeneration of the filter so that the amount of soot remaining in the filter is less than the predetermined amount. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0012] According to the control device, the control method, and the engine system of the present disclosure, the amount of soot remaining after the regeneration is completed can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an overview configuration view of an engine system according to a first embodiment to a third embodiment of the present disclosure. Fig. 2 is a block diagram illustrating a configuration example of an ECU according to the first embodiment to the third embodiment of the present disclosure. Fig. 3 is a flowchart illustrating an operation example of the ECU according to the first embodiment of the present disclosure. Fig. 4 is a timing chart schematically illustrating an operation example of the first embodiment of the present disclosure. Fig. 5 is a flowchart illustrating an operation example of the ECU according to the second embodiment of the present disclosure. Fig. 6 is a timing chart schematically illustrating an operation example of the second embodiment of the present disclosure. Fig. 7 is a flowchart illustrating an operation example of the ECU according to the third embodiment of the present disclosure. Fig. 8 is a timing chart schematically illustrating an operation example of the third embodiment of the present disclosure. DESCRIPTION OF EMBODIMENTS

[0013] Embodiments of the present disclosure will be described below with reference to the drawings. Fig. 1 is an overview configuration view of an engine system according to a first embodiment to a third embodiment of the present disclosure. Fig. 2 is a block diagram illustrating a configuration example of an ECU according to the first embodiment to the third embodiment of the present disclosure. Fig. 3 is a flowchart illustrating an operation example of the ECU according to the first embodiment of the present disclosure. Fig. 4 is a timing chart schematically illustrating an operation example of the first embodiment of the present disclosure. Fig. 5 is a flowchart illustrating an operation example of the ECU according to the second embodiment of the present disclosure. Fig. 6 is a timing chart schematically illustrating an operation example of the second embodiment of the present disclosure. Fig. 7 is a flowchart illustrating an operation example of the ECU according to the third embodiment of the present disclosure. Fig. 8 is a timing chart schematically illustrating an operation example of the third embodiment of the present disclosure. Note that the same or corresponding configurations in the respective drawings are denoted by the same reference numerals, and their descriptions will be omitted where appropriate. First embodimentOverview of the engine system configuration

[0014] Fig. 1 schematically illustrates an overview of the configuration of an engine system 10 according to the first embodiment to the third embodiment. The engine system 10 is a system including a diesel engine 1 (hereinafter also referred to as an engine), a control system of the engine 1, and an exhaust gas purification device. The engine 1 is mounted on a work machine used for tasks such as excavation work or transporting earth and sand on a construction site such as a mine or a road. In this case, the work machine includes a construction machine such as a hydraulic excavator, a wheel loader, a bulldozer, a grader, and a crane, as well as a transport vehicle such as a dump truck and a forklift. However, the engine system 10 of the present embodiment is not limited to mounting on a work machine and can be used in various vehicles and machines.

[0015] The Fig. The engine system 10 illustrated in FIG. 1 includes the engine 1, a turbocharger 2, an engine control unit (ECU) 100, a vehicle controller 200, and an exhaust gas purification device 300. The engine 1 is, for example, a multi-cylinder diesel engine and is provided with an engine speed sensor 91 that detects the engine speed, a fuel injector 11 (omitted from the illustration) that injects fuel into the engine 1, and the like. Detection data of the engine speed sensor 91 is output to the ECU 100 via a signal line 90. Further, the ECU 100 controls the amount of fuel injected from the fuel injector 11 or the like according to a signal indicating the degree of accelerator opening transmitted from the vehicle controller 200 or the like. For example, the signal line 90 includes a communication line for a Controller Area Network (CAN), a signal line for each sensor, and the like.Furthermore, the turbocharger 2 compresses the air supplied to the engine 1 by rotating a turbine through the exhaust gas of the engine 1. Exhaust gas purification device

[0016] The exhaust gas purification device 300 is a device that performs post-treatment such as collecting and reducing residual substances such as PM and nitrogen oxides (NOx) in the exhaust gas of the engine 1 and is controlled by the ECU 100. The exhaust gas purification device 300 includes an exhaust throttle valve 71, a fuel injection device 72, a DPF device 5, a urea-water injection device 73, and a selective catalyst reduction (hereinafter referred to as "SCR") device 6 in the order listed from upstream in a flow direction of the exhaust gas discharged from the engine 1. The DPF device 5 includes a diesel oxidation catalyst (hereinafter referred to as "DOC") 51 and a DPF 52. The DPF device 5, the SCR device 6, and the like are provided in an exhaust passage 3 through which the exhaust gas of the engine 1 flows.The exhaust passage 3 includes an inlet pipe 31 that carries the exhaust gas from the turbocharger 2 connected to the engine 1 to the DPF device 5, an outlet pipe 32 that connects the DPF device 5 and the SCR device 6, and an outlet pipe 33 that is connected to an outlet of the SCR device 6. Furthermore, a mechanism that distributes the urea water supplied from the urea water injection device 73 is provided in the outlet pipe 32. exhaust throttle valve

[0017] The exhaust throttle valve 71 is configured by a shutoff valve or the like arranged in the intake pipe 31. The valve opening degree of the exhaust throttle valve 71 is controlled by the ECU 100, and the temperature of the exhaust gas is controlled by adjusting the valve opening degree. When the valve opening degree is reduced, the exhaust gas upstream of the exhaust throttle valve 71 is compressed, and the pressure and temperature of the exhaust gas flowing through the exhaust passage 3 are increased. DPF device

[0018] As described above, the DPF device 5 includes the DOC 51 and the DPF 52, and the regeneration of the DPF 52 is carried out by the action of the DOC 51. The DPF device 5 collects PM in the DPF 52. Soot in the PM collected downstream is oxidized to carbon dioxide by nitrogen dioxide, which is converted by, for example, the DOC 51 located upstream of the DPF 52. In this way, soot is removed.

[0019] The DOC 51 includes a housing, and the diesel oxidation catalyst is housed in the housing. The DOC 51 is a catalyst that oxidizes and heats a fuel (hereinafter referred to as "metered fuel") supplied to the exhaust gas as needed (the supply of the metered fuel is referred to as "fuel metering"). This raises the exhaust temperature to a predetermined high-temperature range. For example, the DPF 52 is regenerated as described above using the exhaust gas at the elevated temperature, and the exhaust pipe 32 and the like are regenerated by decomposing and removing a urea deposit accumulated in the exhaust pipe 32 and the like, as described later. The metered fuel is, for example, diesel fuel, which is the same as the engine fuel.When the metered fuel is supplied to an engine cylinder, the metered fuel is supplied into the engine cylinder by post-injection by the fuel injection device 11. Furthermore, in the present embodiment, the metered fuel injection device 72 provided on the intake pipe 31 supplies the fuel to the exhaust gas, and the fuel flows into the DOC 51 along with the exhaust gas. Urea-water injection device

[0020] The urea-water injection device 73 is a device that adds an aqueous urea solution to the exhaust gas as an aqueous reducing agent solution. The urea-water injection device 73 is an injection nozzle that is attached to the outlet pipe 32 of the DPF device 5 and injects the aqueous urea solution into the outlet pipe 32. A pump unit (omitted from the illustration) is connected to the urea-water injection device 73 and supplies the urea-water solution from a urea-water tank (omitted from the illustration) in which the urea-water solution is stored to the injection nozzle. The ECU 100 controls the urea-water injection device 73 and the pump unit, and injects the urea-water solution from the urea-water injection device 73 into the outlet pipe 32. The aqueous urea solution injected into the outlet pipe 32 is hydrolyzed by the heat of the exhaust gas and converted into ammonia. SCR device

[0021] The SCR device 6 is a device that reduces and purifies nitrogen oxides in the exhaust gas by using ammonia obtained by hydrolysis of the urea aqueous solution as a reducing agent. Ammonia is supplied to the SCR device 6 along with the exhaust gas as a reducing agent. Note that an ammonia oxidation catalyst may be provided downstream of the SCR device 6. The ammonia oxidation catalyst oxidizes and neutralizes unused ammonia in the SCR device 6, thereby reducing exhaust emissions. When the urea aqueous solution is injected from the urea-water injection device 73, urea may crystallize and precipitate in the exhaust pipe 32. Therefore, it is necessary to perform a regeneration process to decompose the precipitate (urea deposit) inside the exhaust pipe 32 by adjusting the exhaust gas temperature to a high temperature.It should be noted that regeneration in the embodiment of the present disclosure refers to both the regeneration of the DPF device 5 described above and a regeneration in which the urea deposit in the outlet pipe 32 is decomposed. sensor

[0022] The exhaust gas purification device 300 is provided with various sensors that detect the conditions of the diesel engine 1 and the exhaust gas purification device 300. Thus, the DPF device 5 is provided with an inlet temperature sensor 92 that measures the inlet temperature of the DOC 51, an outlet temperature sensor 93 that measures the outlet temperature of the DOC 51, and a differential pressure sensor 94 that measures the differential pressure upstream and downstream of the DPF 52. It should be noted that, for example, in addition to the Fig. 1, one or a plurality of NOx sensors that detect the concentration of nitrogen oxides contained in the exhaust gas, an outlet temperature sensor that measures an outlet temperature of the DPF 52, an SCR outlet temperature sensor that measures an outlet temperature of the SCR device 6, and the like are arranged. The output signal of each of the sensors is transmitted to the ECU 100 via the signal line 90. At this time, the output of the differential pressure sensor 94 is monitored as a value indicative of an internal resistance value of the DPF 52. Furthermore, the outlet temperature of the DOC 51 corresponds to the inlet temperature of the DPF 52 and the regeneration temperature of the DPF 52. Vehicle control

[0023] For example, the vehicle controller 200 controls all units of the work machine to which the engine 1 is attached by inputting a signal indicating the operating state (on state, off state, operating amount, etc.) of each operating device (omitted from the illustration) and transmitting and receiving predetermined data to and from another controller such as the ECU 100. In the present embodiment, the vehicle controller 200 transmits, for example, data indicating an accelerator opening degree to the ECU 100. Here, the operating device includes, for example, an accelerator pedal, a brake, a steering lever, a shift lever, a work implement lever, and the like. The accelerator pedal is a device that sets the speed (rotational speed) of the engine 1 (or its acceleration degree) and is in a form such as an accelerator pedal or throttle lever.In the present embodiment, the degree of operation of the accelerator pedal is referred to as “accelerator opening degree”. ECU

[0024] Next, a configuration of the ECU 100 will be described. The ECU 100 may be configured using a computer such as a microcomputer, as well as peripheral circuits and peripheral devices, and includes the respective Fig. 2 as a functional configuration configured by a combination of hardware, such as a computer, and software, such as a program executed by the computer, or the like. Thus, the ECU 100, as shown in Fig. 2, an information acquisition unit 101, an ash accumulation amount estimation unit 102, and a regeneration control unit 103. It should be noted that Fig. 2 illustrates only a part of the functional configuration of the ECU 100, which mainly relates to the regeneration of the exhaust gas purification device 300, and other parts related to the control of the fuel injection device 11 and the like are omitted from the illustration. Furthermore, the ECU 100 is a configuration example of the control device of the present disclosure. Information collection unit

[0025] The information acquisition unit 101 repeatedly acquires, in a predetermined cycle, measurement data from each of the sensors such as the engine speed sensor 91, the intake temperature sensor 92, the exhaust temperature sensor 93, and the differential pressure sensor 94, and repeatedly acquires, in a predetermined cycle, data indicating the accelerator opening degree and the like from the vehicle controller 200. Ash accumulation quantity estimation unit

[0026] The ash accumulation amount estimation unit 102 estimates an amount of ash accumulated in the DPF 52. The ash accumulation amount estimation unit 102 estimates the amount of ash accumulated in the DPF 52, for example, based on a fuel injection amount injected by the fuel injector 11. As described above, ash is an ash content remaining after a trace amount of engine oil is burned in a combustion chamber of the engine 1. The amount of ash accumulated in the DPF 52 correlates with a fuel injection amount from the fuel injector 11, and the amount of ash can be estimated based on the fuel injection amount.The ash accumulation amount estimation unit 102 calculates a cumulative value of the fuel injection amount based on the accelerator opening degree, the engine speed, and the like detected by the vehicle controller 200, and estimates the amount of ash accumulated in the DPF 52 based on the cumulative value of the fuel injection amount. However, the ash accumulation amount estimation unit 102 may estimate the amount of ash accumulated in the DPF 52 not only based on the fuel injection amount, but also based on an operating time of the engine 1, a fuel consumption amount based on a measurement result of a fuel meter, or the like, the method described in PTL 1, or the like. Regeneration control unit

[0027] The regeneration control unit 103 includes a regeneration state determining unit 1031 and a temperature rise control executing unit 1032. The regeneration state determining unit 1031 determines the presence or absence of a regeneration request and also determines whether the ash amount is equal to or less than a predetermined threshold (assumed to be a threshold value M). For example, the regeneration request is set to "present" when the differential pressure of the DPF 52 measured by the differential pressure sensor 94 exceeds a predetermined threshold, when a predetermined time has passed since the last regeneration, when the regeneration start is instructed by a manual operation of an operator, or in other cases.The threshold value M is a value corresponding to the amount of ash that allows the collection efficiency of the DPF 52 due to ash accumulation to be equal to or greater than a predetermined value even when 100% of the soot accumulated in the DPF 52 is removed by regeneration. Here, the collection efficiency is the ratio of PM flowing out of the DPF 52 to PM entering the DPF 52 and is defined, for example, by a particulate number (PN). The amount of ash accumulated in the DPF 52 is zero when the DPF 52 is new (or substantially zero after the DPF 52 is cleaned) and increases with the increase in operation of the engine 1. When the amount of ash accumulated in the DPF 52 is equal to or less than a predetermined amount (for example, the threshold value M), a predetermined amount of soot remains after regeneration. This allows the collection efficiency to be equal to or greater than a predetermined value.In contrast, in a case where the amount of ash accumulated in the DPF 52 is greater than the predetermined amount (for example, the threshold value M), the collection efficiency may be equal to or greater than the predetermined value even if no soot remains after regeneration (for example, the DPF 52 is regenerated while the remaining amount of soot is zero).

[0028] When a regeneration request is present, the temperature increase control execution unit 1032 executes control to increase the temperature of the exhaust gas at the time of regeneration of the exhaust gas purification device 300 (temperature increase control). During the temperature increase control, the temperature increase control execution unit 1032 sets a target temperature (referred to as "DOC outlet regeneration target temperature TEMPO") for the outlet temperature of the DOC 51 and controls the DOC outlet temperature to fall within a predetermined range, using the DOC outlet regeneration target temperature TEMPO as a reference (TEMPO [°C] to (TEMPO [°C] - TEMPa [°C])). The set value TEMPa is a tolerance in temperature control.

[0029] During the temperature rise control, the temperature rise control execution unit 1032 first controls the valve opening degree of the exhaust throttle valve 71 to increase the exhaust gas temperature. When the intake temperature measured by the intake temperature sensor 92 is equal to or higher than the set temperature, for example, fuel metering is started by post-injection from the fuel injector 11 of the engine 1 and injection from the fuel injector 72. This further increases the exhaust gas temperature. The set temperature at which fuel metering is started is set based on a temperature (light-off temperature) at which the catalyst included in the DOC 51 is activated. The fuel injected during fuel metering is calculated based on a difference between the DOC inlet temperature and the DOC outlet regeneration target temperature, or the like.The metered fuel is supplied to the DOC 51 along with the exhaust gas and generates heat through a chemical reaction with the oxidation catalyst in the DOC 51. Thus, the temperature of the exhaust gas is increased under the control of the valve opening degree of the exhaust throttle valve 71 and continues to rise as it flows through the DOC 51. Furthermore, for example, when the cumulative time during which the DOC outlet temperature exceeds the preset temperature threshold (TEMPO - TEMPa) reaches a preset time threshold (referred to as "time management regeneration time threshold T0"), the temperature rise control execution unit 1032 terminates the temperature rise control and sets the regeneration request to "none." In this case, the time management regeneration time threshold T0 is a regeneration time of the DPF 52.It should be noted that the time during which the DOC outlet temperature exceeds the temperature threshold (TEMPO - TEMPa) may not be continuous over the duration of the time management regeneration time threshold T0. For example, if a cumulative value exceeds the time management regeneration time threshold T0 within a predetermined time, it may be determined that regeneration is complete.

[0030] In the present embodiment, the regeneration control unit 103 controls the regeneration of the DPF 52 so that the temperature rise control execution unit 1032 causes a predetermined amount of soot to remain in the DPF 52 when the regeneration state determining unit 1031 determines that the amount of ash estimated by the ash accumulation amount estimation unit 102 is equal to or less than the threshold value M, and controls the regeneration of the DPF 52 so that the remaining amount of soot in the DPF 52 is less than the predetermined value when the amount of ash is greater than the threshold value M.Here, in the first embodiment, the regeneration control unit 103 adjusts the remaining amount of soot in the DPF 52 by controlling, by means of the temperature rise control execution unit 1032, the regeneration in the case where the ash amount is equal to or less than the threshold value M so that the outlet temperature of the DOC 51 (the regeneration temperature of the DPF 52) is lower than when the ash amount is above the threshold value M, and the regeneration in the case where the ash amount is equal to or less than the threshold value M so that the outlet temperature of the DOC 51 is higher than when the temperature is when the ash amount is equal to or less than the threshold value M. Operating example of the first embodiment

[0031] Fig. 3 illustrates an example of processing for a single regeneration by the ECU 100 according to the first embodiment of the present disclosure. Fig. The process illustrated in Figure 3 is started when the regeneration request is present. If the Fig. 3 is started, the temperature rise control execution unit 1032 starts the temperature rise control (step S11). Subsequently, the ash accumulation amount estimation unit 102 estimates an ash accumulation amount (hereinafter also referred to as "estimated ash accumulation amount") (step S12). Subsequently, the regeneration state determination unit 1031 determines whether the estimated ash accumulation amount is greater than the threshold value M (step S13).

[0032] When the estimated ash accumulation amount is greater than the threshold value M (step S13: YES), the temperature increase control execution unit 1032 sets the DOC outlet regeneration target temperature TEMPO to a setting value TEMP1 (step S14). When the estimated ash accumulation amount is equal to or less than the threshold value M (step S13: NO), the temperature increase control execution unit 1032 sets the DOC outlet regeneration target temperature TEMPO to a setting value TEMP2 (step S15). Here, the setting value TMEP1 is a value of the DOC outlet regeneration target temperature TEMPO when the ash amount accumulated in the DPF 52 is greater than the threshold value M, and may be a value corresponding to a temperature that causes the soot amount accumulated in the DPF 52 to be zero (or substantially zero), for example.The setting value TMEP2 is a value of the DOC outlet regeneration target temperature TEMPO when the amount of ash accumulated in the DPF 52 is equal to or less than the threshold value M, a value smaller than the setting value TEMP1 (in other words, TEMP2 < TEMP1), and a value that allows a predetermined amount of soot to remain in the DPF 52 so that the collection efficiency is equal to or greater than a predetermined value. Note that the setting values, such as the setting value TEMP1 and the setting value TEMP2, as well as a setting value T1 and a setting value T2 described later, can be set based on, for example, simulation results obtained using models of the engine system 10 and the DPF device 5, test results obtained with an actual engine, or the like.

[0033] Subsequently, the temperature rise control execution unit 1032 determines whether the cumulative regeneration time satisfying "DOC outlet regeneration target temperature TEMPO - TEMPa < DOC outlet temperature" is greater than the time management regeneration time threshold T0 (step S16). If the cumulative regeneration time is greater than the time management regeneration time threshold T0 (step S16: YES), the temperature rise control execution unit 1032 sets the regeneration request to "Not Present", terminates the regeneration (step S17), and terminates the Fig. 3. If the cumulative regeneration time is equal to or less than the time management regeneration time threshold T0 (step S16: NO), the temperature rise control execution unit 1032 returns to step S12 and executes the processing after step S12 again.

[0034] It should be noted that in the description given above, in the Fig. 3, the processing from step S14 to step S17 is executed by the temperature rise control execution unit 1032. However, the processing may be primarily executed, for example, by the regeneration state determination unit 1031. If the result of the processing in step S16 is "NO," the return destination may be step S16, for example.

[0035] Fig. Figure 4 schematically illustrates an overview of the internal resistance of the DPF 52, a regeneration state, and a change in the regeneration temperature over time. The horizontal axis represents time (the total operating time of the engine 1) and the vertical axis represents the internal resistance of the DPF 52, the regeneration state, and the regeneration temperature. The internal resistance of the DPF 52 is expressed in terms of the differential pressure of the DPF 52 [kPa], the accumulated PM amount [g] or [g / L], or the like. The solid line represents the (total) internal resistance of the DPF 52, the dashed line represents the internal resistance of the DPF 52 due to accumulated ash, and the dashed line represents the internal resistance of the DPF 52 due to accumulated ash corresponding to the threshold value M. When the internal resistance of the DPF 52 is represented as the accumulated PM amount [g] or [g / L], the solid line represents the total accumulated PM amount (soot, ash, etc.).), the dashed line represents the accumulated ash amount, and the dotted line represents the accumulated ash amount corresponding to the threshold value M. Note that the internal resistance R1 is a margin from the internal resistance corresponding to the threshold value M. A point CP is a point at which the amount of ash accumulated in the DPF 52 reaches a value corresponding to the threshold value M. The regeneration state indicates whether there is a regeneration request or not. The regeneration temperature is the outlet temperature of the DOC 51 [°C].

[0036] A time ta1 is a time at which the use of a new DPF 52 is started. Fig. In the example illustrated in Fig. 4, the first regeneration is performed from time ta2 to time ta3, the second regeneration from time ta4 to time ta5, the third regeneration from time ta7 to time ta8, the fourth regeneration from time ta9 to time ta10, and the fifth regeneration from time ta11 to time ta12. Further, the ash amount reaches the threshold value M at time ta6. The internal resistance of the DPF, shown by the solid line, gradually increases over time when regeneration is not performed, gradually decreases when regeneration is started, and gradually increases again when regeneration is stopped.

[0037] Before the ash amount reaches the threshold value M at time ta6, the DOC outlet regeneration target temperature TEMPO - setting value TMEPa is controlled to the setting value TEMP2 - setting value TEMPa. After time ta6, the DOC outlet regeneration target temperature TEMPO - setting value TMEPa is controlled to the setting value TEMP1 - setting value TEMPa. The threshold value T0 for the time management regeneration time is the same. In the Fig. 4, the setting value TEMP2 is set so that the internal resistance of the DPF at the time of regeneration completion remains at a level equal to the sum of the threshold value M and the internal resistance R1. Further, the setting value TEMP1 is set so that the soot accumulated in the DPF 52 can be removed to zero (or substantially zero) at the time of regeneration completion. In this case, before time ta6, the internal resistance at the time of regeneration completion is adjusted to a value obtained by adding the internal resistance R1 to the threshold value M. After time ta6, the internal resistance at the time of regeneration completion reaches a value equal to the internal resistance due to the ash accumulation amount. Effects and consequences of the first embodiment

[0038] In the first embodiment, the ECU 100 is a control device of the engine system 10, which includes the engine 1, the DOC 51 (oxidation catalyst) in the exhaust passage 3 of the engine 1, and the DPF 52 (filter) that collects soot in the exhaust passage 3, the soot being contained in the exhaust passage of the engine 1, and the ash accumulation amount estimation unit 102 that estimates the amount of ash accumulated in the DPF 52, and the regeneration control unit 103 that controls the regeneration of the DPF 52 so that a predetermined amount of soot remains in the DPF 52 when the amount of ash is less than the predetermined threshold value M, and controls the regeneration of the DPF 52 so that the remaining amount of soot in the DPF 52 is less than the predetermined value when the amount of ash is greater than the threshold value M.With this configuration, when the amount of ash accumulated in the DPF 52 is greater than the threshold M, the remaining amount of soot after completion of the regeneration of the DPF 52 can be easily reduced.

[0039] Note that in the first embodiment, the regeneration control unit 103 adjusts a remaining amount by controlling, when the ash amount is equal to or less than the threshold M, the regeneration so that the outlet temperature of the DOC 51 is lower than when the ash amount is greater than the threshold M, and when the ash amount is greater than the threshold M, the regeneration so that the outlet temperature of the DOC 51 is higher than when the ash amount is equal to or less than the threshold M. With this configuration, the regeneration temperature of the DPF 52 is changed depending on whether the ash amount is equal to or less than the threshold M. This makes it possible to adjust the remaining soot amount. Second embodiment

[0040] Next, with reference to Fig. 5 and Fig. 6, a second embodiment of the present disclosure is described. The configurations of the engine system 10 and the ECU 100 according to the second embodiment are basically the same as the configurations in the first embodiment described with reference to Fig. 1 and Fig. 2. However, the first and second embodiments differ from each other in certain aspects of the operation of the regeneration control unit 103 of the ECU 100. In the first embodiment, the regeneration temperature in the regeneration of the DPF 52 is changed depending on whether the ash amount is equal to or less than the threshold value M. In contrast, in the second embodiment, the regeneration time in the regeneration of the DPF 52 is changed depending on whether the ash amount is equal to or less than the threshold value M. The second embodiment will be described below, focusing mainly on the differences from the first embodiment.

[0041] In the present embodiment, similarly to the first embodiment, the regeneration control unit 103 controls the regeneration of the DPF 52 so that the temperature rise control execution unit 1032 causes a predetermined amount of soot to remain in the DPF 52 when the regeneration state determining unit 1031 determines that the amount of ash estimated by the ash accumulation amount estimation unit 102 is equal to or less than the threshold value M, and controls the regeneration of the DPF 52 so that the remaining amount of soot in the DPF 52 is less than the predetermined value when the amount of ash is greater than the threshold value M.Here, in the second embodiment, the regeneration control unit 103 adjusts the remaining soot amount in the DPF 52 by controlling, by means of the temperature rise control execution unit 1032, when the ash amount is equal to or less than the threshold value M, the regeneration so that the regeneration time of the DPF 52 is shorter than the time when the ash amount is greater than the threshold value M, and, when the ash amount is greater than the threshold value M, the regeneration so that the regeneration time of the DPF 52 is longer than the time when the ash amount is equal to or less than the threshold value M. Operating example of the second embodiment

[0042] Fig. 5 illustrates an example of processing for a single regeneration by the ECU 100 according to the second embodiment of the present disclosure. Compared to the Fig. 3 illustrated process differ in the Fig. 5 illustrates the contents of the Fig. 5, which corresponds to the step S14b shown in Fig. 3, and the contents of the Fig. 5, which corresponds to the step S15b shown in Fig. 3, corresponds to step S15 of the first embodiment. The other steps are the same in the first embodiment and the second embodiment.

[0043] If the Fig. 5, the estimated ash accumulation amount is greater than the threshold value M (step S13: YES), the temperature rise control execution unit 1032 sets the time management regeneration time threshold value T0 to the setting value T1 (step S14b). If the estimated ash accumulation amount is equal to or less than the threshold value M (step S13: NO), the temperature rise control execution unit 1032 sets the time management regeneration time threshold value T0 to the setting value T2 (step S15b). Here, the setting value T1 may be a value of the threshold value T0 of the time management regeneration time when the ash amount accumulated in the DPF 52 is greater than the threshold value M, and may be a value corresponding to a regeneration time at which the soot amount accumulated in the DPF 52 may be, for example, zero (or substantially zero).The setting value T2 is a value of the threshold value T0 of the time management regeneration time when the amount of ash accumulated in the DPF 52 is equal to or less than the threshold value M, a value less than the setting value T1 (in other words, T2 < T1), and a value that allows a predetermined amount of soot to remain in the DPF 52 so that the collection efficiency is equal to or greater than a predetermined value.

[0044] Similar to Fig. 4 illustrates Fig. 6 schematically shows an overview of the internal resistance of the DPF 52, a regeneration state, and a temporal change in the regeneration temperature. A time tb1 is a time at which the use of a new DPF 52 begins. In the Fig. In the example illustrated in Fig. 6, the first regeneration is performed from time tb2 to time tb3, the second regeneration from time tb4 to time tb5, the third regeneration from time tb7 to time tb8, the fourth regeneration from time tb9 to time tb10, and the fifth regeneration from time tb11 to time tb12. Further, the ash amount reaches the threshold value M at time tb6. The internal resistance of the DPF, shown by the solid line, gradually increases over time when regeneration is not performed, gradually decreases when regeneration is started, and gradually increases again when regeneration is stopped.

[0045] Before the ash amount reaches the threshold value M at time tb6, the regeneration time is controlled to the set value T2. After time tb6, the regeneration time is controlled to the set value T1. The DOC outlet regeneration target temperature TEMPO and the set value TEMPa are identical. Fig. 6, the setting value T2 is set so that the internal resistance of the DPF 52 at the time of regeneration completion remains at a level equal to the sum of the threshold value M and the internal resistance R1. Further, the setting value T1 is set so that the soot accumulated in the DPF 52 can be removed to zero (or substantially zero) at the time of regeneration completion. In this case, before time tb6, the internal resistance at the time of regeneration completion is adjusted to a value obtained by adding the internal resistance R1 to the threshold value M. After time tb6, the internal resistance at the time of regeneration completion reaches a value equal to the internal resistance due to the ash accumulation amount. Effects and consequences of the second embodiment

[0046] In the second embodiment, the ECU 100 is a control device of the engine system 10, which includes the engine 1, the DOC 51 (oxidation catalyst) in the exhaust passage 3 of the engine 1, and the DPF 52 (filter) that collects soot in the exhaust passage 3, the soot being contained in the exhaust passage of the engine 1, and the ash accumulation amount estimation unit 102 that estimates the amount of ash accumulated in the DPF 52, and the regeneration control unit 103 that controls the regeneration of the DPF 52 so that a predetermined amount of soot remains in the DPF 52 when the amount of ash is less than the predetermined threshold value M, and controls the regeneration of the DPF 52 so that the remaining amount of soot in the DPF 52 is less than the predetermined value when the amount of ash is greater than the threshold value M.With this configuration, when the amount of ash accumulated in the DPF 52 is greater than the threshold M, the remaining amount of soot after completion of the regeneration of the DPF 52 can be easily reduced.

[0047] Here, in the second embodiment, the regeneration control unit 103 adjusts the remaining amount by controlling the regeneration when the ash amount is equal to or less than the threshold value M so that the regeneration time of the DPF 52 is shorter than when the ash amount is greater than the threshold value M, and controlling the regeneration when the ash amount is greater than the threshold value M so that the regeneration time of the DPF 52 is longer than when the ash amount is equal to or less than the threshold value M. With this configuration, the regeneration time of the DPF 52 is changed depending on whether the ash amount is equal to or less than the threshold value M. This makes it possible to adjust the remaining soot amount. Third embodiment

[0048] Next, with reference to Fig. 7 and Fig. 8, a third embodiment of the present disclosure is described. The configurations of the engine system 10 and the ECU 100 according to the third embodiment are basically the same as the configurations in the first embodiment described with reference to Fig. 1 and Fig. 2. However, the first and third embodiments differ from each other in certain aspects of the operation of the regeneration control unit 103 of the ECU 100. In the first embodiment, the regeneration temperature in the regeneration of the DPF 52 is changed depending on whether the ash amount is equal to or less than the threshold value M. In contrast, in the third embodiment, the regeneration temperature and the regeneration time in the regeneration of the DPF 52 are changed depending on whether the ash amount is equal to or less than the threshold value M. The third embodiment will be described below, focusing mainly on the differences from the first embodiment.

[0049] In the present embodiment, similarly to the first embodiment, the regeneration control unit 103 controls the regeneration of the DPF 52 so that the temperature rise control execution unit 1032 retains a predetermined amount of soot in the DPF 52 when the regeneration state determining unit 1031 determines that the ash amount estimated by the ash accumulation amount estimation unit 102 is equal to or less than the threshold value M, and controls the regeneration of the DPF 52 so that the remaining amount of soot in the DPF 52 is less than the predetermined value when the ash amount is greater than the threshold value M.Here, in the third embodiment, the regeneration control unit 103 adjusts the remaining amount of soot in the DPF 52 by means of the temperature rise control execution unit 1032 by, when the ash amount is equal to or less than the threshold value M, controlling the regeneration so that the regeneration temperature of the DPF 52 is lower than the temperature when the ash amount is greater than the threshold value M and the regeneration time of the DPF 52 is shorter than the time when the ash amount is greater than the threshold value M, and, when the ash amount is greater than the threshold value M, controlling the regeneration so that the regeneration temperature of the DPF 52 is higher than the temperature when the ash amount is greater than the threshold value M and the regeneration time of the DPF 52 is longer than the time when the ash amount is equal to or less than the threshold value M. Operating example of the third embodiment

[0050] Fig. Fig. 7 illustrates an example of processing for a single regeneration by the ECU 100 according to the third embodiment of the present disclosure. Compared to the Fig. 3 illustrated process differ in the Fig. 7 illustrated the contents of the Fig. 7 illustrated step S14c, which corresponds to the Fig. 3, and the contents of the Fig. 7 illustrated step S 15c, which corresponds to the Fig. 3, corresponds to that in the first embodiment. The other steps are the same in the first embodiment and the third embodiment.

[0051] If the Fig. 7, the estimated ash accumulation amount is greater than the threshold value M (step S13: YES), the temperature rise control execution unit 1032 sets the DOC outlet regeneration target temperature TEMPO to the setting value TEMP1 and sets the time management regeneration time threshold T0 to the setting value T1 (step S14c). If the estimated ash accumulation amount is equal to or less than the threshold value M (step S13: NO), the temperature rise control execution unit 1032 sets the DOC outlet regeneration target temperature TEMPO to the setting value TEMP2 and sets the time management regeneration time threshold T0 to the setting value T2 (step S15b).Here, the setting value TEMP1 and the setting value T1 are a value of the DOC outlet regeneration target temperature TEMPO and a value of the time management regeneration time threshold T0 when the amount of ash accumulated in the DPF 52 is greater than the threshold M. For example, when the DOC outlet regeneration target temperature TEMPO is the setting value TEMP1 and the time management regeneration time threshold T0 is the setting value T1, the setting value TEMP1 and the setting value T1 may be values corresponding to such a combination of a regeneration temperature and a regeneration time that an amount of soot accumulated in the DPF 52 may be zero (or substantially zero).The setting value TEMP2 and the setting value T2 are a value of the DOC outlet regeneration target temperature TEMPO and a value of the time management regeneration time threshold T0 when the amount of ash accumulated in the DPF 52 is equal to or less than the threshold M, a value less than the setting value TEMP1 and a value less than the setting value T1, respectively (in other words, TEMP2 < TEMP1 and T2 < T1), and are a combination of values that allow a predetermined amount of soot to remain in the DPF 52 so that the collection efficiency is equal to or greater than a predetermined value.

[0052] Similar to Fig. 4 illustrates Fig. Figure 8 shows a schematic overview of the internal resistance of the DPF 52, a regeneration state, and a temporal change in the regeneration temperature. A time tc1 is the time at which the use of a new DPF 52 begins. Fig. In the example illustrated in Fig. 8, the first regeneration is performed from time tc2 to time tc3, the second regeneration from time tc4 to time tc5, the third regeneration from time tc7 to time tc8, the fourth regeneration from time tc9 to time tc10, and the fifth regeneration from time tc11 to time tc12. Further, the ash amount reaches the threshold value M at time tc6. The internal resistance of the DPF, shown by the solid line, gradually increases over time when regeneration is not performed, gradually decreases when regeneration is started, and gradually increases again when regeneration is stopped.

[0053] Before the ash amount reaches the threshold value M at time tc6, the DOC outlet regeneration target temperature TEMPO - setting value TMEPa is controlled to the setting value TEMP2 - setting value TEMPa, and the regeneration time is controlled to the setting value T2. After time tc6, the DOC outlet regeneration target temperature TEMPO - setting value TMEPa is controlled to the setting value TEMP1 - setting value TEMPa, and the regeneration time is controlled to the setting value T1. The DOC outlet regeneration target temperature TEMPO and the setting value TEMPa are identical. In the Fig.In the example illustrated in Fig. 8, the setting value TEMP2 and the setting value T2 are set so that the internal resistance of the DPF at the time of regeneration completion remains at a level equal to the sum of the threshold value M and the internal resistance R1. Further, the setting value TEMP1 and the setting value T1 are set so that the soot accumulated in the DPF 52 can be removed to zero (or substantially zero) at the time of regeneration completion. In this case, before time tc6, the internal resistance at the time of regeneration completion is adjusted to a value obtained by adding the internal resistance R1 to the threshold value M. After time tc6, the internal resistance at the time of regeneration completion reaches a value equal to the internal resistance due to the amount of ash accumulation. Effects and consequences of the third embodiment

[0054] In the third embodiment, the ECU 100 is a control device of the engine system 10, which includes the engine 1, the DOC 51 (oxidation catalyst) in the exhaust passage 3 of the engine 1, and the DPF 52 (filter) that collects soot in the exhaust passage 3, the soot being contained in the exhaust passage of the engine 1, and the ash accumulation amount unit 102 that estimates the amount of ash accumulated in the DPF 52, and the regeneration control unit 103 that controls the regeneration of the DPF 52 so that a predetermined amount of soot remains in the DPF 52 when the amount of ash is less than the predetermined threshold value M, and controls the regeneration of the DPF 52 so that the remaining amount of soot in the DPF 52 is less than the predetermined value when the amount of ash is greater than the threshold value M.With this configuration, when the amount of ash accumulated in the DPF 52 is greater than the threshold M, the remaining amount of soot after completion of the regeneration of the DPF 52 can be easily reduced.

[0055] At this time, in the third embodiment, the regeneration control unit 103 adjusts the remaining soot amount by controlling the regeneration when the ash amount is equal to or less than the threshold value M so that the outlet temperature of the DOC 51 is lower and the regeneration time of the DPF 52 is shorter than when the ash amount is greater than the threshold value M, and controlling the regeneration when the ash amount is greater than the threshold value M so that the outlet temperature of the DOC 51 is higher and the regeneration time of the DPF 52 is longer than when the ash amount is equal to or less than the threshold value M. Effects and implications of the present disclosure

[0056] According to the present disclosure, the regeneration of the DPF 52 is controlled so that the remaining amount of soot in the DPF 52 is less than the predetermined amount when the ash amount is greater than the predetermined threshold M. When the ash amount is greater than the predetermined threshold M, the amount of soot remaining after the regeneration of the DPF 52 is completed can be easily reduced. Examples of variations and the like

[0057] The embodiments of the present disclosure are described above with reference to the drawings. However, the specific configurations are not limited to the above-mentioned embodiments and include design changes and the like that do not depart from the gist of the present disclosure. For example, the device that increases the temperature of the exhaust gas may be a combustor, a variable turbocharger, or the like. Note that in comparisons with threshold values and the like, "equal to or less than" may be interpreted as "less than," and "greater than" may be interpreted as "equal to or greater than." Furthermore, part or all of the program executed by the computer in the above-mentioned embodiments may be distributed via a computer-readable recording medium or a communication line. Additional information

[0058] The control device (ECU 100) of the embodiments can be understood as follows. (1) The control device (ECU 100) according to a first aspect of the present disclosure is the control device of the engine system 10 including the engine 1, the oxidation catalyst (DOC 51) provided in the exhaust passage 3 of the engine 1, and the filter (DPF 52), and is configured to collect soot within the exhaust passage 3, the soot being contained in the exhaust gas of the engine 1, the control device including: the ash accumulation amount estimation unit 102 configured to estimate an amount of ash accumulated in the filter; and the regeneration control unit 103 configured to, when the ash amount is equal to or less than a predetermined threshold, control the regeneration of the filter so that a predetermined amount of soot remains in the filter, and, when the ash amount is greater than the threshold, control the regeneration of the filter so that the remaining amount of soot in the filter is less than the predetermined amount.According to this aspect and each of the following aspects, the amount of soot remaining after regeneration is completed can be reduced. (2) A control device according to a second aspect of the present disclosure is the control device according to (1), wherein the regeneration control unit adjusts the remaining amount by, when the ash amount is equal to or less than the threshold, controlling the regeneration so that an outlet temperature of the oxidation catalyst is lower than when the ash amount is greater than the threshold, and when the ash amount is greater than the threshold, controlling the regeneration so that the outlet temperature of the oxidation catalyst is higher than when the ash amount is equal to or less than the threshold. (3) A control device according to a third aspect of the present disclosure is the control device according to (1), wherein the regeneration control unit adjusts the remaining amount by, when the ash amount is equal to or less than the threshold, controlling the regeneration so that a regeneration time of the filter is shorter than when the ash amount is greater than the threshold, and when the ash amount is greater than the threshold, controlling the regeneration so that the regeneration time of the filter is longer than when the ash amount is equal to or less than the threshold. (4) A control device according to a fourth aspect of the present disclosure is the control device according to (1), wherein the regeneration control unit adjusts the remaining amount by, when the ash amount is equal to or less than the threshold, controlling the regeneration so that an outlet temperature of the oxidation catalyst is lower and a regeneration time of the filter is shorter than when the ash amount is greater than the threshold, and when the ash amount is greater than the threshold, controlling the regeneration so that the outlet temperature of the oxidation catalyst is higher and the regeneration time of the filter is longer than when the ash amount is equal to or less than the threshold. (5) A control device according to a fifth aspect of the present disclosure is the control device according to any one of (1) to (4), wherein the ash accumulation amount estimation unit estimates the ash amount based on a fuel injection amount. According to this aspect, the ash amount can be estimated based on a fuel injection amount. Industrial applicability

[0059] According to the aspect described above, the amount of soot remaining after the regeneration is completed can be reduced. List of reference symbols

[0060] 10 Engine system, 100 ECU, 101 Information acquisition unit, 102 Ash accumulation amount estimation unit, 103 Regeneration control unit, 1031 Regeneration state determining unit, 1032 Temperature rise control execution unit, 1 Engine, 2 Turbocharger, 11, 72 Fuel injection device, 300 Exhaust gas purification device, 3 Exhaust passage, 71 Exhaust throttle valve, 5 DPF device, 51 DOC, 52 DPF, 73 Urea-water injection device, 6 SCR device, 91 Engine speed sensor, 92 Intake temperature sensor, 93 Exhaust temperature sensor, 94 Differential pressure sensor QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Zitierte Patentliteratur

[0000] JP 2023-004425

[0002] JP 2005-307746 A

[0006] Zitierte Nicht-Patentliteratur

[0000] Koji Tsuneyoshi, Osamu Takagi und Kazuhiro Yamamoto, „Effect of Surface Roughness on Initial PM Filtration Efficiency of DPF“, Transactions of the Japan Society of Mechanical Engineers, Series B, The Japan Society of Mechanical Engineers, Bd. 76, Nr. 767, 25. Juli, 2010, S. 100-107 (S. 1110-1117

[0006] Akira Usui, Toru Uenishi, Takao Fukuma und Hitoshi Kusaka, „Evaluation of Diesel Particulate Filter with Ash Deposit“, Transactions of the Society of Automotive Engineers of Japan, Inc., Society of Automotive Engineers of Japan, Bd. 49, Nr. 4, Juli 2018, S. 690-695

[0006]

Claims

[1] A control device of an engine system comprising an engine, an oxidation catalyst provided in an exhaust passage of the engine, and a filter configured to collect soot in the exhaust passage, the soot being contained in the exhaust gas of the engine, the control device comprising: an ash accumulation amount estimation unit configured to estimate an amount of ash accumulated in the filter; and a regeneration control unit configured to, when the amount of ash is equal to or less than a predetermined threshold, control the regeneration of the filter so that a predetermined amount of soot remains in the filter, and, when the amount of ash is greater than the threshold, control the regeneration of the filter so that the remaining amount of soot in the filter is less than the predetermined amount. [2] The control device according to claim 1, wherein the regeneration control unit adjusts the remaining amount by, when the ash amount is equal to or less than the threshold value, controlling the regeneration so that an outlet temperature of the oxidation catalyst is lower than when the ash amount is greater than the threshold value, and when the ash amount is greater than the threshold value, controlling the regeneration so that the outlet temperature of the oxidation catalyst is higher than when the ash amount is equal to or less than the threshold value. [3] The control device according to claim 1, wherein the regeneration control unit adjusts the remaining amount by, when the ash amount is equal to or less than the threshold, controlling the regeneration so that a regeneration time of the filter is shorter than when the ash amount is greater than the threshold, and when the ash amount is greater than the threshold, controlling the regeneration so that the regeneration time of the filter is longer than when the ash amount is equal to or less than the threshold. [4] The control device according to claim 1, wherein the regeneration control unit adjusts the remaining amount by, when the ash amount is equal to or less than the threshold value, controlling the regeneration so that an outlet temperature of the oxidation catalyst is lower and a regeneration time of the filter is shorter than when the ash amount is greater than the threshold value, and by, when the ash amount is greater than the threshold value, controlling the regeneration so that the outlet temperature of the oxidation catalyst is higher and the regeneration time of the filter is longer than when the ash amount is equal to or less than the threshold value. [5] The control device according to any one of claims 1 to 4, wherein the ash accumulation amount estimation unit estimates the ash amount based on the amount of injected fuel. [6] A control method of an engine system comprising an engine, an oxidation catalyst provided in an exhaust passage of the engine, and a filter configured to collect soot in the exhaust passage, the soot being contained in the exhaust gas of the engine, the control method comprising: a) estimating an amount of ash accumulated in the filter; and if the amount of ash is equal to or less than a predetermined threshold, controlling the regeneration of the filter so that a predetermined amount of soot remains in the filter, and if the amount of ash is greater than the threshold, controlling the regeneration of the filter so that the remaining amount of soot in the filter is less than the predetermined amount. [7] Engine system, comprising: an engine; an oxidation catalyst provided in an exhaust passage of the engine; a filter configured to collect soot in the exhaust passage, the soot being contained in the exhaust gas of the engine; and a control device configured to control the regeneration of the filter, wherein the control device includes: an ash accumulation amount estimation unit configured to estimate an amount of ash accumulated in the filter; and a regeneration control unit configured to, when the amount of ash is equal to or less than a predetermined threshold, control the regeneration of the filter so that a predetermined amount of soot remains in the filter, and, when the amount of ash is greater than the threshold, control the regeneration of the filter so that the remaining amount of soot in the filter is less than the predetermined amount.

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