Vehicle control device

Abstract

To provide a vehicle control device having improved performance property in a circuit mode.SOLUTION: A vehicle control device includes: a mode determination part that determines whether or not a travel mode of a vehicle is switched to a circuit mode; and a start sound control part that, in a case of affirmative determination by the mode determination part, executes start sound increase processing of increasing start sound of a travel power source of the vehicle more than that in a case of negative determination by the mode determination part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] There are vehicles whose driving mode can be switched to a circuit mode (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2015-199382 Summary of the Invention [Problem to be solved by the invention]

[0004] When the driving mode is switched to the circuit mode, it is desirable to have a distinctive feature that differentiates the circuit mode from the other modes.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle control device that improves the performance in circuit mode. [Means for solving the problem]

[0006] The above objective can be achieved by a vehicle control device that includes a mode determination unit that determines whether the vehicle's driving mode has been switched to circuit mode, and a start-up sound control unit that, if the mode determination unit makes a positive determination, executes a start-up sound increase process that increases the start-up sound of the vehicle's driving power source more than if the mode determination unit makes a negative determination.

[0007] The driving power source is an engine, and when the mode determination unit makes a positive judgment, the start-up sound control unit may execute the start-up sound increase processing by increasing the revving speed of the engine at start-up more than when the mode determination unit makes a negative judgment.

[0008] The engine may be provided with a fuel cut control unit that executes a fuel cut process for the engine when the engine speed during idle operation is equal to or higher than a fuel cut speed that is higher than a target idle speed, and the fuel cut control unit may set the fuel cut speed to a higher value while the start-up noise increase process is being executed than when the start-up noise increase process is stopped.

[0009] The system may include an abnormality determination unit that determines that an abnormality has occurred in the engine if the torque of the engine becomes higher than a predetermined reference value by a predetermined value or more while the startup noise increase process is being executed, and the reference value may be set to the torque of the engine while the startup noise increase process is being executed when the engine is normal.

[0010] The startup sound control unit may stop the startup sound increase process after a predetermined time has elapsed since the start of the startup sound increase process. [Effects of the Invention]

[0011] According to the present invention, a vehicle control device can be provided that has improved performance in circuit mode. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic configuration diagram of a vehicle. [Figure 2] 10 is a flowchart illustrating performance control. [Figure 3] 10 is a timing chart illustrating performance control. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Vehicle outline] FIG. 1 is a schematic diagram showing the overall configuration of a vehicle 1. The vehicle 1 includes an engine (ENG) 10, a torque converter (T / C) 12, and an automatic transmission (A / T) 14. The engine 10 is a gasoline engine, but may also be a diesel engine. The engine 10 is started by being cranked by a starter 9. A torque converter 12 is connected to a crankshaft 11 of the engine 10. A turbine shaft 13 of the torque converter 12 is connected to the input side of the automatic transmission 14, and the driving force of the engine 10 is transmitted to the automatic transmission 14. An output shaft 15 of the automatic transmission 14 is connected to a differential gear 16, which is a final reduction gear. Left and right axles 17 are connected to the differential gear 16. The driving force transmitted to the output shaft 15 is transmitted to drive wheels 18 via the axles 17.

[0014] The automatic transmission 14 is a stepped transmission that includes a plurality of hydraulic friction engagement elements and a planetary gear device. The automatic transmission 14 is switched between P (parking) range, R (reverse) range, N (neutral) range, and D (drive) range by selectively engaging the plurality of friction engagement elements.

[0015] The ECU (Electronic Control Unit) 20 is an electronic control unit that performs control processing related to the vehicle 1. The ECU 20 is a computer that includes a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The ECU 20 is an example of a vehicle control device, and functionally realizes a mode determination unit, a start-up sound control unit, a fuel cut control unit, and an abnormality determination unit, which will be described in detail later.

[0016] The ECU 20 is connected to a crank angle sensor 21, a shift position sensor 22, an air flow meter 23, an accelerator opening sensor 24, a mode selector switch 25, and a vehicle speed sensor 26. The crank angle sensor 21 detects the engine speed. The shift position sensor 22 detects the position of the shift lever. The air flow meter 23 detects the amount of intake air into the engine 10. The accelerator opening sensor 24 detects the accelerator opening, which is the opening of the accelerator pedal. The mode selector switch 25 can switch between driving modes, which will be described later. The vehicle speed sensor 26 detects the vehicle speed.

[0017] The ECU 20 calculates the required torque and target rotation speed of the engine 10 based on the engine rotation speed, intake air amount, and accelerator opening detected by the above sensors. The ECU 20 controls the fuel injection amount, intake air amount, and ignition timing according to the required torque and target rotation speed. For example, when the engine 10 is in an idling state, the ECU 20 controls the fuel injection amount, intake air amount, and ignition timing so that the engine rotation speed becomes the target idle rotation speed and the engine torque becomes the supply torque.

[0018] The ECU 20 can switch the driving mode between normal mode, sport mode, eco mode, and circuit mode. The driver can switch the driving mode between normal mode, sport mode, and eco mode by operating the mode selector switch 25. Regarding circuit mode, for example, when the vehicle 1 is at a circuit, the driver can switch the driving mode to circuit mode by operating a mobile terminal such as a smartphone. When the driving mode is switched to circuit mode, the control map of the vehicle 1 is switched to a control map that prioritizes driving performance corresponding to the circuit mode. This improves the driving performance of the vehicle 1 compared to driving modes other than circuit mode. Note that switching to circuit mode may also be performed by the mode selector switch 25 as described above.

[0019] The ECU 20 executes a fuel cut process to stop fuel injection into the engine 10 when a predetermined condition is met. Specifically, when the engine speed reaches or exceeds a fuel cut speed, the ECU 20 executes the fuel cut process for the engine 10. The fuel cut speed is set to a value higher than the target idle speed. This improves fuel efficiency. The fuel cut is also executed during idle operation. The fuel cut process is an example of a process executed by a fuel cut control unit.

[0020] [Production Control] FIG. 2 is a flowchart illustrating the performance control. This control is continuously repeated while the ignition is on. The ECU 20 determines whether the driving mode has been switched to the circuit mode (step S1). If the answer is No in step S1, this control ends. Step S1 is an example of processing executed by the mode determination unit. If the answer is Yes in step S1, the ECU 20 determines whether there is a request to start the engine 10 (step S2). If the answer is No in step S2, this control ends.

[0021] If the answer is Yes in step S2, it is determined whether or not the preconditions for executing the start-up sound increase process, which will be described later, are met (step S3). The preconditions are, for example, that the vehicle is stopped, the accelerator opening is zero, and the shift range is N range. As will be described in detail later, the start-up sound increase process increases the revving speed of the engine 10 when it is started. By executing the start-up sound increase process when the above preconditions are met, safety is ensured. If the answer is No in step S3, this control ends.

[0022] If step S3 is Yes, the ECU 20 executes a start process for the engine 10 (step S4) and executes a start sound increase process (step S5). The start process is a process in which the starter 9 cranks the engine 10 and starts fuel injection when the engine speed reaches a predetermined value or higher. The start sound increase process is a process in which the start sound of the engine 10 is increased compared to when the driving mode is other than the circuit mode. Specifically, the start sound is increased by increasing the revving speed of the engine 10 at start-up. The revving speed is the engine speed that is higher than the target idle speed immediately after starting the engine 10. The increase in the revving speed is achieved by increasing the throttle opening at start-up and increasing the fuel injection amount compared to when the driving mode is other than the circuit mode. Since the start sound of the engine 10 is thus louder, the performance of the circuit mode is improved. Step S5 is an example of a process executed by the start sound control unit.

[0023] Next, ECU 20 sets the fuel cutoff rotation speed to a higher value while the start-up sound increase process is being executed than when the start-up sound increase process is stopped (step S6). While the start-up sound increase process is being executed, the revving rotation speed increases as described above. Because the fuel cutoff rotation speed is set to a high value while the start-up sound increase process is being executed, it is possible to prevent the revving rotation speed during the execution of the start-up sound increase process from exceeding the fuel cutoff rotation speed and causing the fuel cutoff process to be executed. Step S6 is an example of processing executed by the fuel cut control unit.

[0024] Next, the ECU 20 determines whether the engine torque is higher than a predetermined reference value by a predetermined value or more (step S7). The reference value is set to the engine torque when the engine 10 is operating normally and the starting noise increase process is being executed. The reference value is obtained in advance through experiments and stored in the ROM of the ECU 20. The engine torque may be calculated based on the intake air amount detected by the air flow meter 23, for example, or may be detected by a torque sensor. Step S7 is an example of processing executed by the abnormality determination unit.

[0025] If the answer is No in step S7, the ECU 20 then determines whether a predetermined time has elapsed since the start of the startup sound increase process (step S8). If the answer is No in step S8, step S5 and subsequent steps are executed again.

[0026] If the answer is Yes in step S8, the ECU 20 stops the start-up noise increase process (step S9). As described above, the start-up noise increase process increases the engine speed at startup of the engine 10. For this reason, the start-up noise increase process is stopped for safety reasons. Note that stopping the start-up noise increase process returns the fuel cut-off speed and reference value described above to their original low values.

[0027] If the result of step S7 is Yes, the ECU 20 determines that an abnormality has occurred in the engine 10 (step S10) and executes a process to ensure safety (step S11). The process to ensure safety includes, for example, a process to stop the startup noise increase process and limit the vehicle speed, or a process to forcibly stop the engine 10. Step S10 is an example of a process executed by the abnormality determination unit.

[0028] Fig. 3 is a timing chart illustrating the performance control. Fig. 3 shows the driving state of the starter, engine speed, on / off state of the start-up sound increase processing flag, throttle opening, and engine torque over time. Fig. 3 also shows reference values for determining whether an abnormality has occurred in the engine 10 while the start-up sound increase processing described above is being executed. Fig. 3 also shows the transition of the ISC required torque. The ISC required torque is the engine torque required for the engine speed to converge to the target idle speed.

[0029] When a request to start the engine 10 is made in circuit mode, the starter 9 is actuated (time t1), and the engine speed begins to increase (time t2). After that, the start sound increase processing flag is switched on, the throttle opening increases by a predetermined amount, combustion begins, and torque increases (time t3). Then, the starter 9 is stopped (time t4). The engine torque begins to increase further (time t5).

[0030] When the engine speed reaches or exceeds the predetermined number of times of termination determination, the start-up noise increase process flag is switched off, the throttle opening is reduced to its original opening, and torque is reduced (time t6). The fuel cut-off rotation speed during execution of the start-up noise increase process is set to a value higher than the number of times of termination determination. Thereafter, the engine torque converges to the ISC required torque, and the engine speed converges to the target idle rotation speed. In this manner, the start-up noise increase process is stopped after a predetermined time has elapsed, as described above. In other words, in this embodiment, when the engine speed reaches or exceeds the predetermined number of times of termination determination, it is considered that a predetermined time has elapsed since the start-up noise increase process began, and the start-up noise increase process is stopped. Alternatively, the time since the start-up noise increase process flag was switched on may be measured, and the start-up noise increase process may be stopped when the measured time has elapsed.

[0031] As shown in FIG. 3, while the start-up noise increase process is being executed, the reference value fluctuates in accordance with the transition of engine torque under normal conditions. For example, if the engine torque becomes higher than the ISC required torque by a predetermined value or more while the start-up noise increase process is being executed, it may be determined that an abnormality has occurred in the engine 10. However, in this case, the difference between the peak value of the engine torque and the ISC required torque increases (time t6) due to the execution of the start-up noise increase process, and there is a risk of an erroneous determination that an abnormality has occurred in the engine 10. Therefore, the reference value used for abnormality determination while the start-up noise increase process is being executed is set to the engine torque during execution of the start-up noise increase process when the engine 10 is normal. This prevents the above-mentioned erroneous determination. The reference value is set to a value corresponding to the engine speed by referring to a map corresponding to the engine speed during execution of the start-up noise increase process when the engine 10 is normal.

[0032] In the above embodiment, the ECU 20 installed in an engine vehicle has been described as an example of a vehicle control device, but the vehicle equipped with such an ECU may also be a hybrid vehicle equipped with an engine and a motor as a power source for running. Furthermore, in the case of an electric vehicle equipped only with a motor as a power source for running, a start-up sound increase process may be performed by outputting a sound simulating the engine start-up sound from a speaker installed in the vehicle cabin when the motor starts. This also improves the performance in the circuit mode.

[0033] 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 as defined in the claims. [Explanation of symbols]

[0034] 1 vehicle 10 Engine 20 ECU (vehicle control device, mode determination unit, start-up sound control unit, fuel cut control unit, abnormality determination unit)

Claims

1. a mode determination unit that determines whether the vehicle driving mode has been switched to a circuit mode; A vehicle control device comprising: a start-up sound control unit that, when the mode determination unit makes a positive judgment, executes a start-up sound increase process to increase the start-up sound of the vehicle's driving power source more than when the mode determination unit makes a negative judgment.

2. the driving power source is an engine, 2. The vehicle control device of claim 1, wherein when the mode determination unit makes a positive judgment, the start-up sound control unit executes the start-up sound increase process by increasing the engine revving speed at start-up more than when the mode determination unit makes a negative judgment.

3. a fuel cut control unit that executes a fuel cut process for the engine when the engine speed in an idle operation state is equal to or higher than a fuel cut speed that is higher than a target idle speed, 3. The vehicle control device according to claim 2, wherein the fuel cut control unit sets the fuel cut rotation speed to a higher value while the start-up sound increase process is being executed than while the start-up sound increase process is stopped.

4. an abnormality determination unit that determines that an abnormality has occurred in the engine when a torque of the engine becomes higher than a predetermined reference value by a predetermined value or more during execution of the startup noise increase process; 4. The vehicle control device according to claim 3, wherein the reference value is set to a torque of the engine during execution of the starting noise increasing process when the engine is operating normally.

5. 5. The vehicle control device according to claim 2, wherein the startup sound control unit stops the startup sound increase process after a predetermined time has elapsed since the start of the startup sound increase process.

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