Control device for engine

Abstract

To suppress an excessive learning in peripheral learning.SOLUTION: A control device for an engine performs a peripheral learning in which, when learning ignition timing for an engine operating point, for an ignition timing map showing the relationship between engine operating points and ignition timing, which is used when setting the engine ignition timing, the ignition timing for the operating point related to the learning is updated using a learned value, and the ignition timing for operating points surrounding the operating point related to the learning is updated using a value corresponding to the learned value. At this time, peripheral learning is performed only on the ignition timing of operating points that are within a range of a predetermined value from the learned value among the ignition timing of operating points surrounding the operating point related to the learning.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a control system for an engine, and more particularly to a control system for an engine that learns an ignition timing map used to set ignition timing for the engine. [Background technology]

[0002] Conventionally, as this type of engine control device, one that calculates ignition timing based on a basic learning value, a multi-point learning value, and a basic ignition timing has been proposed (see, for example, Patent Document 1). In this control device, a plurality of basic learning regions are set based on the engine operating conditions, and a plurality of multi-point learning regions are set within one of the plurality of basic learning regions based on the engine operating conditions, and the basic learning value is updated when the engine operating state is in any of the basic learning regions, and the multi-point learning value is updated when the engine operating state is in any of the multi-point learning regions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-209886 A Summary of the Invention [Problem to be solved by the invention]

[0004] A peripheral learning method has also been proposed in which, when the ignition timing of a certain operating point of the engine is learned, the ignition timing of operating points around that operating point is also learned according to the learning point. However, when the engine is repeatedly operated in a specific operating range, there are cases in which the ignition timing at the operating points around that operating point is learned excessively only on the advance side or only on the retard side.

[0005] The engine control device of the present disclosure has a primary objective of suppressing excessive learning in peripheral learning. [Means for solving the problem]

[0006] The engine control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The engine control device according to the present disclosure includes: An engine control device that performs peripheral learning in which, when an ignition timing map showing a relationship between an engine operation point and an ignition timing used for setting an ignition timing of the engine is learned, the ignition timing of the operation point related to the learning is updated using a learned value, and the ignition timing of operation points surrounding the operation point related to the learning is updated using a value corresponding to the learned value, peripheral learning is performed only on the ignition timing of a driving point that is within a range of a predetermined value from the learned value among the ignition timings of driving points surrounding the driving point related to the learning; It is characterized by:

[0008] In the engine control device disclosed herein, when the ignition timing is learned for an engine operating point, the ignition timing of the operating point related to the learning is updated using a learned value, and the ignition timing of operating points around the operating point related to the learning is updated using a value corresponding to the learned value, thereby performing peripheral learning. At this time, peripheral learning is performed only for the ignition timing of operating points around the operating point related to the learning that are within a predetermined range from the learned value. This makes it possible to suppress excessive peripheral learning in which the ignition timing is excessively learned only on the advance side or only on the retard side.

[0009] In the engine control device of the present disclosure, when the ignition timing of the operating point related to the learning is learned to the advance side, peripheral learning may be performed only on the ignition timing of the operating point that is within the range of the learning value to the advance side of the predetermined value among the ignition timings of the surrounding operating points, and when the ignition timing of the operating point related to the learning is learned to the retard side, peripheral learning may be performed only on the ignition timing of the operating point that is within the range of the learning value to the retard side of the ignition timing of the surrounding operating points. In this way, learning to the advance side is not performed for ignition timings that exceed the predetermined value from the learning value to the advance side, and learning to the retard side is not performed for ignition timings that exceed the predetermined value from the learning value to the retard side, so that excessive peripheral learning in which the ignition timing is excessively learned only on the advance side or only on the retard side can be suppressed.

[0010] In the engine control device of the present disclosure, when learning the ignition timing of the driving points around the driving point related to the learning, the ignition timing may be learned so that the closer the driving point is to the learning driving point, the greater the influence of the learning value. In this way, the effect of the learning can be reflected more significantly for the driving point closer to the learning driving point, and a more appropriate ignition timing map can be created.

[0011] In the engine control device of the present disclosure, the operation point of the engine may be represented by a load factor of the engine and a rotation speed of the engine. [Brief description of the drawings]

[0012] [Figure 1] 1 is a configuration diagram showing a schematic configuration of an engine device 10 including an engine control device according to an embodiment. [Diagram 2] 4 is a flowchart showing an example of an ignition timing learning process executed by an electronic control unit 40. [Diagram 3] FIG. 2 is an explanatory diagram showing an example of an ignition timing map showing an example of the relationship between a load factor KL, a rotation speed Ne, and an ignition timing θ as an operation point of the engine 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a configuration diagram showing a schematic configuration of an engine device 10 including an engine control device according to an embodiment. As shown in the figure, the engine device 10 includes an engine 12 and an electronic control unit 40. The engine device 10 is mounted, for example, on an engine vehicle that runs using power from the engine 12, or on a hybrid vehicle that includes a motor in addition to the engine 12. The electronic control unit 40 corresponds to the engine control device.

[0014] The engine 12 is configured as a four-cylinder internal combustion engine that outputs power through four strokes: intake, compression, expansion (explosive combustion), and exhaust, using a mixed fuel of gasoline and alcohol (e.g., ethanol) from a fuel tank. The engine 12 includes a port injection valve 26 that injects fuel into an intake port, an in-cylinder injection valve 27 that injects fuel into a cylinder, and an ignition plug 30. The in-cylinder injection valve 27 is disposed approximately at the center of the top of a combustion chamber 29, and injects fuel in a spray form. The ignition plug 30 is disposed near the in-cylinder injection valve 27 so as to be able to ignite the fuel injected in a spray form from the in-cylinder injection valve 27.

[0015] The engine 12 is equipped with a port injection valve 26 and an in-cylinder injection valve 27, and can be operated while switching the injection mode Mi between a port injection mode, an in-cylinder injection mode, and a common injection mode, and switching the in-cylinder injection number Nd, which is the number of injections by the in-cylinder injection valve 27 in the in-cylinder injection mode and the common injection mode, based on the operating state of the engine 12. In the port injection mode, air cleaned by the air cleaner 22 is sucked into the intake pipe 23 and passes through the throttle valve 24 and the surge tank 25, and fuel is injected from the port injection valve 26 downstream of the surge tank 25 of the intake pipe 23 to mix the air and fuel. Then, the mixture is sucked into the combustion chamber 29 via the intake valve 28 and explodes and burns due to an electric spark from the spark plug 30. Then, the reciprocating motion of the piston 32, which is pushed down in the cylinder bore 31 by the energy, is converted into the rotational motion of the crankshaft 14. In the in-cylinder injection mode, air is drawn into the combustion chamber 29 in the same manner as in the port injection mode, and fuel is injected from the in-cylinder injection valve 27 in one or multiple injections during the intake stroke or compression stroke, and is explosively combusted by an electric spark from the spark plug 30 to rotate the crankshaft 14. In the common injection mode, When air is drawn into the combustion chamber 29, fuel is injected from the port injection valve 26, and fuel is injected once or in multiple batches from the in-cylinder injection valve 27 during the intake stroke and compression stroke, and the fuel is exploded and burned by an electric spark from an ignition plug 30, generating rotational motion for the crankshaft 14. Exhaust discharged from the combustion chamber 29 into an exhaust pipe 34 via an exhaust valve 33 is discharged into the outside air via a purification device 35. The purification device 35 has a catalyst (three-way catalyst) 35a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

[0016] The electronic control unit 40 includes a microcomputer, which has a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. The electronic control unit 40 receives signals from various sensors via the input ports. For example, the electronic control unit 40 receives a crank angle θcr from a crank position sensor 14a that detects the rotational position of the crankshaft 14 of the engine 12, and a coolant temperature Tw from a water temperature sensor 15 that detects the temperature of the coolant of the engine 12. The electronic control unit 40 also receives cam angles θci and θco from a cam position sensor 16 that detects the rotational position of an intake camshaft that opens and closes the intake valve 28 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 33. The electronic control unit 40 also receives an intake air amount Qa from an air flow meter 23a that is attached upstream of the throttle valve 24 of the intake pipe 23, and an intake air temperature Ta from a temperature sensor 23t that is attached upstream of the throttle valve 24 of the intake pipe 23. The electronic control unit 40 also receives as input the throttle opening TH from a throttle position sensor 24a that detects the position (opening) of the throttle valve 24, and the surge pressure Ps from a pressure sensor 25a attached to the surge tank 25. The electronic control unit 40 also receives as input a front air-fuel ratio AF1 from a front air-fuel ratio sensor 37 attached to the exhaust pipe 34 upstream of the purification device 35, and a rear air-fuel ratio AF2 from a rear air-fuel ratio sensor 38 attached to the exhaust pipe 34 downstream of the purification device 35.

[0017] The electronic control unit 40 outputs various control signals via the output port. For example, the electronic control unit 40 outputs a control signal to the throttle valve 24, a control signal to the port injection valve 26, a control signal to the in-cylinder injection valve 27, and a control signal to the spark plug 30. The electronic control unit 40 calculates the rotation speed Ne of the engine 12 based on the crank angle θcr, and calculates the load factor KL of the engine 12 based on the intake air amount Qa and the rotation speed Ne. The load factor KL is defined as the ratio of the volume of air actually taken in one cycle to the stroke volume per cycle of the engine 12. The electronic control unit 40 determines the relationship between the operation point of the engine (the load factor KL of the engine 12 and the operation point of the rotation speed Ne of the engine 12) and the ignition timing θ in advance by experiments, machine learning, etc., and stores it as an ignition timing map. When the load factor KL and the rotation speed Ne are given, the electronic control unit 40 derives and sets the corresponding ignition timing θ from the ignition timing map, and ignites at that timing.

[0018] The electronic control unit 40 learns the ignition timing in the ignition timing map. Figure 2 is a flowchart showing an example of an ignition timing learning process executed by the electronic control unit 40. This process is repeatedly executed at predetermined time intervals.

[0019] When the ignition timing learning process is executed, the electronic control unit 40 waits for the ignition timing to be learned (step S100). When the ignition timing has been learned, a learned value is set to the ignition timing of an operating point of the engine 12 related to the learning of the ignition timing map (hereinafter referred to as a learning operating point) (step S110).

[0020] Next, it is determined whether the learned value is on the advance side from the existing value (step S120). When it is determined that the learned value is on the advance side from the existing value, the ignition timing is learned on the advance side with a reflection rate of 60% for the ignition timing of the operation point closest to the learning operation point within a predetermined range from the learning value to the advance side (step S130), and the ignition timing is learned on the advance side with a reflection rate of 30% for the ignition timing of the operation point next closest to the learning operation point within a predetermined range from the learning value to the advance side (step S140), and this process is terminated. FIG. 3 is an explanatory diagram showing an example of an ignition timing map showing an example of the relationship between the load factor KL, the rotation speed Ne, and the ignition timing θ as the operation points of the engine 12. The circles in the map are the learned ignition timing θ, and the ignition timing θ of the operation points other than the circles is obtained by interpolation using the most recently learned ignition timing θ. Consider the case where the ignition timing of an operating point marked with a black circle in the map is learned on the advance side from value 14 to value 15 and the predetermined value is value 2. In this case, the ignition timing θ of the learned operating point is set to the value 15, and peripheral learning is performed on the advance side only for the ignition timing of operating points within the range of the learned value (value 15) by the predetermined value (value 2) on the advance side, with a reflection rate of 60% for the most recent operating point and 30% for the next most recent operating point. In the enlarged view of Fig. 3, for the ignition timings at the driving points immediately adjacent to the learning driving point in the center (ignition timing with value 16 in upper right block A, ignition timing with value 15 in lower left block C, and ignition timing with value 10 in lower right block D), learning on the advance side is performed with a reflection rate of 60% (learning of +0.6), and for the ignition timings at the next closest driving points (ignition timings with values ​​17, 15, and 17 in upper right block A, ignition timings with values ​​13, 14, and 13 in lower left block C, and ignition timings with values ​​8, 6, and 12 in lower right block D), learning on the advance side is performed with a reflection rate of 30% (learning of +0.3). Note that for each ignition timing in upper left block B of the learning driving point in the center, the learning value (value 15) falls outside the range of the predetermined value (value 2) on the advance side, so peripheral learning on the advance side is not performed.

[0021] When it is determined in step S120 that the learned value is not on the advance side from the existing value (is on the retard side), the ignition timing is learned to the retard side with a reflection rate of 60% for the ignition timing of the driving point closest to the learned driving point within a predetermined range on the retard side from the learned value (step S150), and the ignition timing is learned to the retard side with a reflection rate of 30% for the ignition timing of the next closest driving point within a predetermined range on the retard side from the learned value (step S160), and this process is terminated. In the enlarged view of Figure 3, consider the case where the ignition timing of the driving point marked with a black circle in the map is learned to the retard side from value 16 to value 15 and the predetermined value is value 2. In this case, the ignition timing θ of the learning operating point is set to a value of 15, and peripheral learning is performed on the retard side only for the ignition timing of operating points within a range of a predetermined value (value 2) on the retard side from the learning value (value 15), with a reflection rate of 60% for the most recent operating point and 30% for the next most recent operating point. In the enlarged view of Fig. 3, for the ignition timing at the driving point closest to the learning driving point in the center (ignition timing of value 16 in upper right block A, ignition timing of value 19 in upper left block B, and ignition timing of value 15 in lower left block C), learning on the retard side is performed with a reflection rate of 60% (learning of -0.6), and for the ignition timing at the next closest driving point (ignition timing of values ​​17, 15, and 17 in upper right block A, ignition timing of values ​​20, 21, and 18 in upper left block B, and ignition timing of values ​​13, 14, and 13 in lower left block C), learning on the retard side is performed with a reflection rate of 30% (learning of -0.3). Note that for the ignition timing in the lower right block D of the learning driving point in the center, the learning value (value 15) falls outside the range of the predetermined value (value 2) on the retard side, so peripheral learning on the retard side is not performed.

[0022] In the electronic control unit 40 in the engine device 10 described above, when the ignition timing θ of the operating point of the engine 12 is learned, if the learned value is on the advance side from the existing value, peripheral learning is performed to advance the ignition timing of the operating point that is within a predetermined range from the learning value to the advance side among the ignition timings of the operating points closest to the learning operating point and the next closest to the learning operating point, and if the learned value is on the retard side from the existing value, peripheral learning is performed to retard the ignition timing of the operating point that is within a predetermined range from the learning value to the retard side among the ignition timings of the operating points closest to the learning operating point and the next closest to the learning operating point. This makes it possible to suppress peripheral learning to the excessive advance side or retard side. Moreover, peripheral learning is performed with a reflection rate of 60% for the ignition timing of the operating point closest to the learning operating point, and peripheral learning is performed with a reflection rate of 30% for the ignition timing of the operating point next to the learning operating point, so that peripheral learning can be performed more appropriately and the ignition timing map can be made more appropriate.

[0023] In the electronic control unit 40 of the engine device 10 of the embodiment, when the ignition timing θ of the operating point of the engine 12 is learned, if the learned value is on the advance side from the existing value, the ignition timing is peripherally learned to the advance side with respect to the ignition timing of the operating point that is within a predetermined value range from the learning value among the ignition timings of the operating points closest to the learning operating point and the next closest to the learning operating point, and when the learned value is on the retard side from the existing value, the ignition timing is peripherally learned to the retard side with respect to the ignition timing of the operating point that is within a predetermined value range from the learning value among the ignition timings of the operating points closest to the learning operating point and the next closest to the learning operating point. However, when the ignition timing θ of the operating point of the engine 12 is learned, the ignition timing may be peripherally learned to the advance side and retard side with respect to the ignition timing of the operating point that is within a predetermined value range from the learning value, regardless of whether it is on the advance side or retard side from the learning value among the ignition timings of the operating points closest to the learning operating point and the next closest to the learning operating point.

[0024] In the electronic control unit 40 of the engine device 10 of the embodiment, the ignition timing of the operating point closest to the learning operating point is peripherally learned with a reflection rate of 60%, and the ignition timing of the operating point next to the learning operating point is peripherally learned with a reflection rate of 30%. However, since the reflection rate can be increased as the operating point approaches the learning operating point, it is not necessary to be bound by the reflection rate of the embodiment. Also, peripheral learning may be performed only on the ignition timing of the operating point closest to the learning operating point.

[0025] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problems will be described below. In the embodiment, the engine 12 corresponds to the "engine" and the electronic control unit 40 corresponds to the "control device."

[0026] The main elements of the embodiment and the main points of the invention described in the section on means for solving the problems are as follows: The correspondence with the elements does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the mode for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0027] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0028] The present disclosure is applicable to the engine control device manufacturing industry and the like. [Explanation of symbols]

[0029] 10 engine device, 12 engine, 14 crankshaft, 14a crank position sensor, 15 water temperature sensor, 16 cam position sensor, 22 air cleaner, 23 intake pipe, 23a air flow meter, 23t temperature sensor, 24 throttle valve, 24a throttle position sensor, 25 surge tank, 25a pressure sensor, 26 port injection valve, 27 in-cylinder injection valve, 28 intake valve, 29 combustion chamber, 30 spark plug, 31 cylinder bore, 32 piston, 33 exhaust valve, 34 exhaust pipe, 35 purification device, 37 front air-fuel ratio sensor, 38 rear air-fuel ratio sensor, 40 electronic control unit.

Claims

1. An engine control device that performs peripheral learning in which, when an ignition timing map showing a relationship between an engine operation point and an ignition timing used for setting an ignition timing of the engine is learned, the ignition timing of the operation point related to the learning is updated using a learned value, and the ignition timing of operation points surrounding the operation point related to the learning is updated using a value corresponding to the learned value, peripheral learning is performed only on the ignition timing of a driving point that is within a range of a predetermined value from the learned value among the ignition timings of driving points surrounding the driving point related to the learning; An engine control device comprising:

2. 2. The engine control device according to claim 1, When learning the ignition timing of the operation point related to the learning to the advance angle side, peripheral learning is performed only on the ignition timing of the operation point of the surrounding operation points that is within the range of the learning value to the advance angle side from the predetermined value, and when learning the ignition timing of the operation point related to the learning to the retard angle side, peripheral learning is performed only on the ignition timing of the operation point of the surrounding operation points that is within the range of the learning value to the retard angle side from the predetermined value. Engine control device.

3. 3. The engine control device according to claim 1, When learning the ignition timing of the driving points around the driving point related to the learning, the ignition timing is learned so that the closer the driving point is to the learning driving point, the more the learning value influences the ignition timing. Engine control device.

4. 3. The engine control device according to claim 1, The engine operation point is represented by a load factor of the engine and a rotation speed of the engine. Engine control device.

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