Vehicle control device

Abstract

To provide a control device of a vehicle which is suppressed in a delay of the learning of a retardation amount of ignition timing.SOLUTION: A control device of a vehicle having an internal combustion engine, and a transmission arranged in a power transmission path between the internal combustion engine and drive wheels comprises: a learning control part for performing learning control for learning a retardation amount of ignition timing according to a generation situation of the knocking of the internal combustion engine; a gear change control part for performing gear change control by controlling the internal combustion engine to an idling operation state when changing a gear stage of the transmission; a first determination part for determining whether or not the gear change control is started during the execution of the learning control; a holding part for holding the retardation amount during the execution of the gear change control when an affirmative determination is performed by the first determination part; and a second determination part for determining whether or not the gear change control is finished. When an affirmative determination is performed by the second determination part, the learning control part continues the learning control from the retardation amount which is held at the holding part.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] There is known a technique for learning the amount of retardation of ignition timing based on the occurrence of knocking in an internal combustion engine (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 07-208310 Summary of the Invention [Problem to be solved by the invention]

[0004] In an idle operation state, the load is small and knocking is unlikely to occur, and the ignition timing is controlled to stabilize the rotation speed, so the above-mentioned learning of the retard amount of the ignition timing is not performed. Therefore, when the engine is controlled from a loaded operation to an idle operation and then returned to a loaded operation, the retard amount learned up to that point is reset to an initial value and relearned anew. However, if the internal combustion engine is controlled to an idle operation state every time a shift control is performed by the transmission, the retard amount is reset to the initial value every time the shift control is performed, which may slow down the progress of learning.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a vehicle control device that suppresses a delay in learning the amount of retardation of the ignition timing. [Means for solving the problem]

[0006] The above object is to provide a control device for a vehicle having an internal combustion engine and a transmission provided in a power transmission path between the internal combustion engine and drive wheels, the control device comprising: a learning control unit that executes learning control to learn an amount of retardation of ignition timing based on an occurrence state of knocking of the internal combustion engine; a gear shift control unit that executes gear shift control by controlling the internal combustion engine to an idling operation state when changing a gear position of the transmission; a first determination unit that determines whether the gear shift control has been started during execution of the learning control; a retention unit that retains the amount of retardation during execution of the gear shift control when a positive determination is made by the first determination unit; and a second determination unit that determines whether the gear shift control has ended, the learning control unit continuing the learning control from the amount of retardation retained in the retention unit when a positive determination is made by the second determination unit. and a third determination unit that determines whether the shift control has not ended within a predetermined time since the shift control was started, and the learning control unit resets the delay amount held in the holding unit to an initial value when a positive determination is made by the third determination unit. This can be achieved by the vehicle's control device.

[0008] In the above configuration, the transmission may be a manual transmission. Effect of the Invention

[0009] According to the present invention, it is possible to provide a vehicle control device that suppresses a delay in learning the amount of retard of the ignition timing. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a vehicle. [Diagram 2] FIG. 2 is a schematic diagram of the engine. [Diagram 3] FIG. 3 is a graph showing a method for setting the ignition timing by learning control. [Figure 4] FIG. 4 is a timing chart showing an example of learning control. [Diagram 5] FIG. 5 is a flowchart showing an example of the learning control executed by the ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Vehicle outline] Fig. 1 is a schematic diagram of a vehicle 1. The vehicle 1 is configured as a manual transmission vehicle (MT vehicle), and as shown in Fig. 1, includes an engine 10, a clutch 30, a manual transmission 50, and an ECU (Electronic Control Unit) 100. The engine 10 is a spark ignition gasoline engine.

[0012] 1, the manual transmission 50 is configured as, for example, a six-speed transmission, and has an input shaft connected to the crankshaft of the engine 10 via the clutch 30, and an output shaft connected to a drive shaft 71. The drive shaft 71 is connected to drive wheels 75 via a differential gear 73. The manual transmission 50 forms each of the first to sixth forward gear stages, connects the input shaft and the output shaft, or releases the connection between them, in response to the operation of a shift lever 52 by the driver.

[0013] The clutch 30 is provided between the engine 10 and the input shaft of the manual transmission 50, and is in an engaged state when the clutch pedal 32 is not depressed by the driver, and is in a slipping engagement state or a released state when the clutch pedal 32 is depressed. When the clutch 30 is in an engaged state, the driving force of the engine 10 is transmitted to the driving wheels 75 via the manual transmission 50, the driving shaft 71, and the differential gear 73. When the clutch 30 is in a released state, the driving force of the engine 10 is not transmitted to the manual transmission 50 or the driving wheels 75. When the clutch 30 is in a slipping engagement state, there is a rotational speed difference between the output shaft of the engine 10 and the input shaft of the manual transmission 50, and power is transmitted from one to the other.

[0014] The ECU 100 executes various controls of the vehicle 1. The ECU 100 includes a central processing unit that executes various arithmetic processes related to the various controls, a non-volatile memory that stores programs and data required for the arithmetic operations, a volatile memory that temporarily stores the arithmetic results of the central processing unit, an input port and an output port for inputting and outputting signals to and from the outside, and the like. The ECU 100 is an example of a control device of the vehicle 1. The ECU 100 also functionally realizes a learning control unit, a shift control unit, a holding unit, and first, second, and third determination units.

[0015] Various sensors are connected to the input port of the ECU 100. The sensors include, for example, a crank angle sensor 21 that detects the rotation speed of the engine 10 (hereinafter referred to as "engine rotation speed NE"), a clutch stroke sensor 22 that detects the stroke of the clutch pedal 32 (hereinafter referred to as "clutch stroke CS"), an ignition switch 23 that detects the on / off state of the ignition, an accelerator position sensor 24 that detects the opening of the accelerator pedal 34 (hereinafter referred to as "accelerator position accp"), a shift position sensor 25 that detects the shift position of the shift lever 52, a vehicle speed sensor 26 that detects the vehicle speed, and the like.

[0016] [Engine outline] FIG. 2 is a schematic diagram showing a schematic configuration of an engine 10. As shown in FIG. 2, air is drawn into a combustion chamber 11 of the engine 10 through an intake passage 12, and fuel injected from a fuel injection valve 13 is supplied to the combustion chamber 11 of the engine 10. When a mixture of the intake air and the injected fuel is ignited by an ignition plug 14, the mixture is burned, causing a piston 15 to reciprocate, and rotating a crankshaft 16 of the engine 10. The mixture after combustion is sent out as exhaust gas from the combustion chamber 11 of the engine 10 to an exhaust passage 17. Note that, in FIG. 2, a port injection valve that injects fuel toward a port of the engine 10 is illustrated as an example of the fuel injection valve 13, but the fuel injection valve 13 is not limited thereto, and may be, for example, an in-cylinder injection valve that directly injects fuel into the combustion chamber 11, or may include both a port injection valve and an in-cylinder injection valve.

[0017] In addition to the sensors mentioned above, the input port of the ECU 100 is connected to a knock sensor 27 that detects the occurrence of knocking in the engine 10, a throttle sensor 28 that detects the opening degree of the throttle valve 19 provided in the intake passage 12, and an air volume sensor 29 that detects the amount of air passing through the intake passage 12.

[0018] The ECU 100 grasps the operating state such as the engine speed NE and the engine load factor KL based on the output signals of various sensors. The ECU 100 outputs command signals to various drive circuits connected to the output ports according to the operating state grasped in this way. The controls performed by the ECU 100 in this way include throttle control for adjusting the opening of the throttle valve 19, fuel injection control for adjusting the injection amount of the fuel injection valve 13, learning control for learning the amount of retardation of the ignition timing in the engine 10 based on the occurrence of knocking, and gear shift control for controlling the gear stage of the manual transmission 50 according to the shift position and the clutch stroke CS.

[0019] [Learning control] The learning control executed by the ECU 100 to learn the amount of retardation of the ignition timing in the engine 10 according to the occurrence of knocking will be described. The ECU 100 determines whether knocking occurs based on the output signal of the knock sensor 27, and executes KSC (Knock Control System) control to optimize the ignition timing so that the ignition timing is advanced as much as possible within a range in which knocking does not occur by gradually advancing the ignition timing from a predetermined timing based on the determination result. At this time, the ECU 100 executes learning control to store and update an annealed value of the amount of retardation of the ignition timing from the predetermined timing as a learning value. This retard amount correlates with the octane number of the fuel, and the retard amount decreases as the octane number of the fuel increases, that is, the ignition timing is set to the advanced side. Thus, the ECU 100 is an example of a learning control unit. Specifically, the learning control of the retard amount is performed as follows.

[0020] 3 is a graph showing a method for setting the ignition timing by learning control. First, the ECU 100 calculates the maximum retarded ignition timing akmf and the basic ignition timing abse based on the engine speed NE and the engine load factor KL. The maximum retarded ignition timing akmf indicates the advance limit ignition timing at which knocking does not occur reliably at the current operating point of the engine 10. The basic ignition timing abse indicates the retarded ignition timing between the ignition timing at which the maximum combustion torque is obtained at the current operating point of the engine 10 and the advance limit ignition timing at which knocking can be suppressed, and is the ignition timing that is preset according to the model of the engine 10.

[0021] Next, the ECU 100 calculates the retard amount akcs from the basic ignition timing abse. The retard amount akcs is an initial value (-a) [° CA] to which a predetermined small advance amount Δα [° CA] is added at predetermined time intervals if knocking does not occur, and a predetermined retard amount (-Δβ) [° CA] is added each time knocking occurs. That is, if knocking does not occur, the retard amount akcs is calculated to approach 0, and if knocking occurs, the retard amount akcs increases in negative angle so as to move away from 0. The magnitude of the advance amount Δα is set to a value smaller than the magnitude of the retard amount (-Δβ). The ECU 100 calculates a retard amount smoothing value akcssm, which is a value obtained by performing a process to slow down the increase / decrease rate of the retard amount akcs calculated in this way according to the occurrence status of knocking, that is, a so-called "smoothing value". The ECU 100 stores and updates this retard angle smoothed value akcssm as a learning value, and calculates the retard angle required amount akcssm as the retard angle required amount aknk. When the retard angle smoothed value akcssm converges to a predetermined value, learning is considered to be completed. When the retard angle smoothed value akcssm becomes 0, the retard angle required amount aknk also becomes 0. The initial value of the retard angle smoothed value akcssm is the same as the initial value of the retard angle amount akcs.

[0022] Here, when the engine 10 is in an idle operation state, the above-mentioned learning control is stopped, and the retard angle smoothing value akcssm is reset to an initial value. After that, when the engine 10 returns from the idle operation state to a load operation state, the learning control of the retard angle smoothing value akcssm is started from the initial value. For example, in the case where the vehicle 1 is an MT vehicle as in this embodiment, the accelerator is released during shifting by the manual transmission 50, and when the accelerator is released, the engine 10 is controlled to an idle operation state. For this reason, for example, when the vehicle 1 starts and accelerates while repeatedly changing gears by the manual transmission 50, the retard angle smoothing value akcssm is reset to the initial value every time a shift is performed by the manual transmission 50, and learning is delayed. In this embodiment, the ECU 100 holds the retard angle smoothing value akcssm without resetting it during the shift control, and when the shift control ends, the learning control is continued from the held retard angle smoothing value akcssm.

[0023] Next, the learning control executed by the ECU 100 will be described. FIG. 4 is a timing chart showing an example of the learning control. FIG. 4 shows the transitions of the engine speed NE, the clutch stroke CS, the gear position, the accelerator opening accp, the idle operation flag Xidle, the KCS control execution flag xkcs, the knock counter csknk, the retard request amount aknk, the retard amount smoothing value akcssm, the vehicle speed, and the shift control execution flag xmtsft. In the example of FIG. 4, the retard request amount aknk and the retard amount smoothing value akcssm are shown with dotted lines in a comparative example in which the learning control is stopped during shift control and the retard amount smoothing value akcssm is reset to an initial value, and the present embodiment in which the retard amount smoothing value akcssm is held during shift control and the learning control is continued from the held retard amount smoothing value akcssm when the shift control ends is shown with solid lines. In the example of Fig. 4, the upper side of the vertical axis indicates the advance side and the lower side indicates the retard side with respect to the retard angle request amount aknk and the retard angle smoothing value akcssm. Also, in the example of Fig. 4, a state in which knocking does not occur and the knock counter csknk is maintained at 0 is shown.

[0024] At time t0, the vehicle 1 is stopped, the vehicle speed is 0, the idle operation flag Xidle is ON, so the KCS control execution flag xkcs is OFF, the accelerator opening accp is 0%, and the engine speed NE is maintained at the idle speed. The clutch stroke CS is 0, the clutch 30 is engaged, the gear is controlled to the first forward gear, and the shift control execution flag xmtsft is OFF. In the idle operation state, the retard request amount aknk is set to the basic ignition timing abse shown in FIG. 3, and the retard amount smoothing value akcssm is set to the initial value.

[0025] At time t1, when the driver depresses the accelerator pedal 34 to start the vehicle 1 and the accelerator opening accp increases, the engine speed NE and vehicle speed gradually increase and the idle operation flag Xidle turns OFF. After a predetermined delay time has elapsed since the idle operation flag Xidle turned OFF, the KCS control execution flag xkcs turns ON and the above-mentioned learning control is executed, the retard angle smoothing value akcssm gradually becomes a value on the advance angle side, and the retard angle request amount aknk is also gradually controlled to the advance angle side.

[0026] At time t2, when the driver releases the accelerator pedal 34 and depresses the clutch pedal 32 in order to change gears, the accelerator opening accp falls to 0, the clutch stroke CS increases, the gear shift control execution flag xmtsft turns ON, and gear shift control is started. At this time, the idle operation flag Xidle turns ON, the KCS control execution flag xkcs turns OFF, and the learning control is stopped.

[0027] After that, the driver operates the shift lever 52 to decrease the clutch stroke CS, and at time t3 the gear shifts from first forward speed to second forward speed, the accelerator opening accp increases, the shift control execution flag xmtsft turns OFF, the shift control ends, and the idle operation flag Xidle turns OFF. After a predetermined delay time has elapsed since the idle operation flag Xidle turned OFF, the KCS control execution flag xkcs turns ON and learning control starts.

[0028] Here, during the period from time t2 to after time t3 when the KCS control execution flag xkcs is OFF, the retard angle smoothed value akcssm in the comparative example is reset to its initial value, whereas the retard angle smoothed value akcssm in this embodiment is held at the value at time t2 during the period when the KCS control execution flag xkcs is OFF. Also, after the KCS control execution flag xkcs turns ON, learning of the retard angle smoothed value akcssm starts from the initial value in the comparative example, whereas learning of the retard angle smoothed value akcssm continues from the held value in this embodiment.

[0029] Similarly, when the shift control starts at time t4 and ends at time t5 when the gear stage is switched to third gear, the retard angle smoothing value akcssm in the comparative example is reset to the initial value again while the KCS control execution flag xkcs is OFF, and learning starts again from the initial value after the KCS control execution flag xkcs is turned ON. In this embodiment, the retard angle smoothing value akcssm is held at the value at time t4 while the KCS control execution flag xkcs is OFF, and learning of the retard angle smoothing value akcssm continues again from the held value after the KCS control execution flag xkcs is turned ON.

[0030] As described above, in the comparative example, the retard angle smoothing value akcssm is reset to the initial value every time the shift control is executed, so that it takes time for learning and for the ignition timing to be controlled to the optimal timing. Therefore, there is a risk of fuel economy and output decreasing during that time. In this embodiment, even if the shift control is executed, the retard angle smoothing value akcssm is held and the learning control continues after the shift control ends, so that the ignition timing can be controlled to the optimal ignition timing early. This makes it possible to ensure fuel economy and output while suppressing knocking. In the example of FIG. 4, the case where the gear stage is shifted up has been described as an example, but this is not limited thereto, and the retard angle smoothing value akcssm is also held during the period when the shift control execution flag xmtsft is ON when the gear stage is shifted down.

[0031] 5 is a flowchart showing an example of learning control executed by the ECU 100. The ECU 100 repeatedly executes this control while the ignition is on. The ECU 100 determines whether or not the learning control is being executed (step S1). As described above, if the KCS control execution flag xkcs is ON, it is determined that the learning control is being executed, and if the KCS control execution flag xkcs is OFF, it is determined that the learning control is stopped. If the answer is No in step S1, this control ends.

[0032] If the answer is Yes in step S1, the ECU 100 judges whether or not the gear shift control has started (step S2). Specifically, if the vehicle speed is equal to or greater than a predetermined value Vα and the clutch stroke CS is equal to or greater than a predetermined value Cα, the ECU 100 judges that the gear shift control has started. For example, the predetermined value Vα is 3 [km / h] and the predetermined value Cα is 20 [%], but is not limited thereto. In other words, as long as it can be determined that the vehicle 1 is traveling and the driver has performed a gear shift operation, the predetermined value Vα and the predetermined value Cα may be values ​​other than those mentioned above. Step S2 is an example of a process executed by the first judgment unit. If the answer is No in step S2, this control ends.

[0033] If the result of step S2 is Yes, the ECU 100 stores the retard angle smoothing value akcssm in, for example, a volatile memory, thereby retaining the value (step S3). The process of step S3 is an example of a process executed by a retaining unit.

[0034] Next, the ECU 100 judges whether the gear shift control has ended (step S4). Specifically, when the shift lever 52 is operated and the clutch stroke CS becomes less than a predetermined value Cα, the ECU 100 judges that the gear shift control has ended. Step S4 is an example of a process executed by the second judgment unit.

[0035] If the result of step S4 is Yes, the ECU 100 continues the learning control using the retained retard angle smoothing value akcssm (step S5). Step S5 is an example of a process executed by the learning control.

[0036] If the result in step S4 is No, it is determined whether or not a predetermined period of time has elapsed since the start of the shift control (step S6). The predetermined period of time is, for example, 5 seconds. The process of step S6 is an example of the process executed by the third determination unit.

[0037] If the answer is No in step S6, the process of step S3 is executed. If the answer is Yes in step S6, the ECU 100 resets the retard angle smoothing value akcssm to the initial value (step S7). This is the case when the shift control is not completed within a predetermined period, for example, when the driver depresses the clutch pedal 32 but does not operate the shift lever 52 within the predetermined period. In this case, if the retard angle smoothing value akcssm is held for a long period, there is a risk that the ignition timing will become unstable after the shift is completed. The process of step S7 is an example of the process executed by the learning control unit.

[0038] In the above embodiment, the vehicle 1 is an MT vehicle equipped with a manual transmission 50, but is not limited thereto. For example, the vehicle may be an automatic transmission vehicle (AT vehicle) equipped with an automatic transmission. Even in an AT vehicle, when the engine is controlled to an idling state during shift control, or when the driver releases the accelerator during shift control and the engine is controlled to an idling state, the delay amount is maintained until the shift control ends, and learning is continued after the shift control ends, thereby suppressing delays in learning.

[0039] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0040] 1 vehicle 10 Engine 14 Spark plug 27 Knock sensor 30 Clutch 32 Clutch pedal 34 Accelerator pedal 50 Manual transmission 100 ECU (control unit)

Claims

1. A control device for a vehicle having an internal combustion engine and a transmission provided in a power transmission path between the internal combustion engine and drive wheels, a learning control unit that executes learning control to learn an ignition timing retard amount capable of suppressing knocking in the internal combustion engine; a gear shift control unit that controls the internal combustion engine to an idle operating state when changing a gear position of the transmission, and executes gear shift control; a first determination unit that determines whether the shift control has been started during execution of the learning control; a holding unit that holds the retard amount during execution of the shift control when a positive determination is made by the first determination unit; a second determination unit that determines whether the shift control has been completed, The learning control unit continues the learning control from the retard amount held in the holding unit when a positive determination is made by the second determination unit, a third determination unit that determines whether the shift control has not ended within a predetermined time since the shift control was started, The learning control unit resets the delay amount held in the holding unit to an initial value when a positive determination is made by the third determination unit.

2. The vehicle control device according to claim 1 , wherein the transmission is a manual transmission.

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