Vehicle control device

Abstract

The present invention addresses the problem of providing a control device for a vehicle capable of exhibiting the driving performance of the vehicle in a racing track mode. This vehicle control device is provided with: a restriction processing unit that, when the vehicle speed of a vehicle exceeds an upper limit vehicle speed, executes vehicle speed restriction processing that restricts the vehicle speed to the upper limit vehicle speed by controlling a traveling power source of the vehicle so as to restrict the driving force of the vehicle to an upper limit driving force; and a switching unit that switches the upper limit vehicle speed from a first speed to a second speed higher than the first speed when the traveling mode of the vehicle is switched to a racing track mode.

Description

Technical Field

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

[0002] There are vehicles that can switch their driving mode to a circuit mode (see, for example, Patent Document 1). Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-199382 Summary of the Invention Problems to be solved by the invention

[0004] If the vehicle speed exceeds the upper speed limit, the vehicle's driving force can be limited to the upper speed limit by limiting the vehicle's driving force to a predetermined upper speed limit. For example, if the driving mode is switched to Track mode, the vehicle's driving performance may not be fully utilized if the vehicle speed is limited to the same upper speed limit as when the driving mode is not Track mode.

[0005] Therefore, an object of the present invention is to provide a vehicle control device capable of bringing out the vehicle's running performance in track mode. Means for solving problems

[0006] The above object can be achieved by a vehicle control device comprising: a speed limit processing unit for executing a speed limit process when a vehicle speed exceeds an upper speed limit, i.e., controlling a driving power source of the vehicle to limit a driving force of the vehicle to an upper speed limit, thereby limiting the vehicle speed to the upper speed limit; and a switching unit for switching the upper speed limit from a first speed to a second speed higher than the first speed when the vehicle's driving mode is switched to a track mode.

[0007] When the requested driving force for the vehicle when the vehicle speed exceeds the upper limit vehicle speed is smaller than the upper limit driving force, the restriction processing unit may set the upper limit driving force to the requested driving force when the vehicle speed exceeds the upper limit vehicle speed.

[0008] The restriction processing unit may gradually reduce the upper limit driving force while the vehicle speed exceeds the upper limit vehicle speed, and gradually increase the upper limit driving force while the vehicle speed is below the upper limit vehicle speed.

[0009] The restriction processing unit may stop the vehicle speed restriction processing when the requested driving force is equal to or less than the upper limit driving force and the vehicle speed is equal to or less than the upper limit vehicle speed.

[0010] The driving power source may also be an engine. Effects of the Invention

[0011] According to the present invention, it is possible to provide a vehicle control device capable of bringing out the vehicle's running performance in a track mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the vehicle. Figure 2 : is a timing chart illustrating the vehicle speed limit process. Figure 3 This is a timing chart illustrating a vehicle speed limit process during downhill travel. Figure 4 : is a flowchart illustrating the vehicle speed limit process. DETAILED DESCRIPTION

[0013] [General structure of the vehicle] Figure 1 This is a schematic diagram showing the general structure of vehicle 1. Vehicle 1 includes an engine (ENG) 10, a torque converter (T / C) 12, and a stepped automatic transmission (A / T) 14. Engine 10 is a gasoline engine, but may also be a diesel engine. The crankshaft 11 of engine 10 is connected to the torque converter 12. The turbine shaft 13 of the torque converter 12 is connected to the input side of the automatic transmission 14, transmitting the driving force of the engine 10 to the automatic transmission 14. The output shaft 15 of the automatic transmission 14 is connected to a differential gear 16 serving as a final reducer. The differential gear 16 is connected to left and right axles 17. The driving force transmitted to the output shaft 15 is transmitted to drive wheels 18 via the axle 17.

[0014] 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, in detail, functionally implements the restriction processing unit and switching unit described below.

[0015] The ECU 20 is connected to a crank angle sensor 21, an air flow meter 23, an accelerator position sensor 24, a mode switch 25, and a vehicle speed sensor 26, and receives the output values of these sensors. The crank angle sensor 21 detects the rotational speed of the engine 10. The air flow meter 23 detects the amount of air intake into the engine 10. The accelerator position sensor 24 detects the degree of opening of the accelerator pedal, i.e., the accelerator position. The mode switch 25 enables switching between driving modes (described later). The vehicle speed sensor 26 detects the driving speed of the vehicle 1.

[0016] The ECU 20 calculates the requested torque for the engine 10 based on the engine speed, intake air volume, and accelerator position detected by the aforementioned sensors. The ECU 20 controls the fuel injection amount, intake air volume, and ignition timing in the engine 10 so that the output torque of the engine 10 matches the requested torque. For example, when the engine 10 is idling, the ECU 20 controls the fuel injection amount, intake air volume, and ignition timing so that the engine speed of the engine 10 matches the target idle speed.

[0017] The ECU 20 can switch the driving mode between normal mode, sport mode, eco mode, and track mode. The driver can operate the mode switch 25 to switch the driving mode between normal mode, sport mode, or eco mode. For example, the driver can switch the driving mode to track mode by operating a mobile device such as a smartphone while the vehicle 1 is at a racetrack. When the driving mode is switched to track mode, the control map of the vehicle 1 is switched to a control map corresponding to track mode that prioritizes driving performance. This improves the driving performance of the vehicle 1 compared to driving modes other than track mode. Switching to track mode can also be performed using the mode switch 25 as described above.

[0018] When specified conditions are met, the ECU 20 executes a speed limit process to limit the vehicle speed to an upper speed limit. Specifically, if the vehicle 1's speed exceeds the upper speed limit, the ECU 20 controls the engine 10, which serves as the driving force for the vehicle 1, to limit the vehicle's driving force to a specified upper speed limit. More specifically, the requested torque for the engine 10 is limited so that the vehicle's driving force reaches the upper speed limit, and the fuel injection amount and intake air amount are limited so that the actual torque of the engine 10 reaches the requested torque. As a result, the vehicle speed is limited to the upper speed limit. Details of the speed limit process are described below.

[0019] [Speed limit processing] Figure 2 : is a timing chart illustrating the vehicle speed limit process. Figure 2The track mode progress / end status, actual vehicle speed, upper limit vehicle speed, actual driving force, upper limit driving force, and requested driving force are displayed. The requested driving force is a requested driving force value of the vehicle 1 calculated based on the accelerator position, the operating state of the engine 10, and the like.

[0020] After the driving mode is switched to Track mode, the upper speed limit is switched to the high side (time t1). Specifically, the upper speed limit is switched from speed Va to speed Vb, which is higher than speed Va. Thus, in Track mode, the vehicle 1 can travel at a speed higher than speed Va and lower than speed Vb. This allows the vehicle 1 to maximize its driving performance in Track mode.

[0021] If the requested driving force increases as the driver increases the accelerator opening, the actual driving force and actual vehicle speed will also increase (time t2). If the actual vehicle speed exceeds the upper limit speed Vb, the upper limit driving force is set from the driving force Fa to the lower driving force side driving force Fb, and the vehicle speed limit process is executed (time t3). As a result, regardless of the requested driving force, the actual driving force is limited by the upper limit driving force, i.e., the driving force Fb. Here, the driving force Fb is set to a driving force that causes the vehicle speed to converge to the upper limit speed, i.e., the speed Vb. In this way, the actual vehicle speed is limited by the speed Vb, ensuring safety.

[0022] Furthermore, while the actual vehicle speed exceeds speed Vb, the upper limit driving force gradually decreases from driving force Fb (time t3 to time t4). While the actual vehicle speed is below speed Vb, the upper limit driving force gradually increases (time t4 to time t5). In this way, the upper limit driving force repeatedly decreases and increases. Consequently, the actual vehicle speed smoothly converges toward speed Vb. This prevents any shocks in vehicle 1 caused by the execution of the speed limit process.

[0023] Furthermore, the driving force Fa set as the upper limit driving force before the actual vehicle speed exceeds speed Vb is the maximum driving force of vehicle 1. That is, when the upper limit driving force is set to driving force Fa, the driving force of vehicle 1 is not limited by driving force Fa. Therefore, when the upper limit driving force is set to driving force Fa, the vehicle speed limit process is not executed.

[0024] Figure 3 1 is a timing chart illustrating a vehicle speed limit process during downhill travel. When the vehicle 1 is traveling downhill in the track mode, the actual vehicle speed increases, and the driver reduces the amount of accelerator pedal depression, thereby reducing the required driving force (time t1).

[0025] After the actual vehicle speed exceeds the speed Vb, the speed limit process is executed (time t2). Here, the requested driving force is less than the upper limit driving force, that is, the driving force Fb. In this case, the case where the upper limit driving force is set to the driving force Fb and the speed limit process is executed is explained as a comparative example. In the comparative example, since the actual driving force is less than the driving force Fb, there is no limit on the actual driving force and there is no limit on the vehicle speed. After the upper limit driving force gradually decreases from the driving force Fb and the upper limit driving force becomes below the actual driving force, the actual driving force is limited (time t3). Like this, there is a time lag from the time when the actual vehicle speed exceeds the speed Vb to the time when the limitation of the actual driving force begins. Therefore, it takes time to limit the actual vehicle speed to the speed Vb.

[0026] In this embodiment, when the requested driving force is less than the driving force Fb when the actual vehicle speed exceeds speed Vb, the upper limit driving force is set to the requested driving force (time t2). This allows the actual driving force to be limited at approximately the same time as the actual vehicle speed exceeds speed Vb. This allows the actual vehicle speed to be limited to speed Vb as quickly as possible.

[0027] Figure 4 : is a flowchart illustrating the vehicle speed limit processing. This control is continuously repeated while the ignition is on. ECU 20 determines whether the driving mode is switched to track mode (step S1). If the answer is no in step S1, this control ends. If the answer is yes in step S1, the upper limit vehicle speed is switched from speed Va to speed Vb (step S2). Step S2 is an example of the processing performed by the switching unit. Next, ECU 20 determines whether the vehicle speed exceeds the upper limit vehicle speed, i.e., speed Vb (step S3). If the answer is no in step S3, this control ends.

[0028] If the answer is yes in step S3, the ECU 20 determines whether the requested driving force is less than the upper limit driving force, i.e., the driving force Fb (step S4). If the answer is no in step S4, the ECU 20 sets the upper limit driving force to the driving force Fb (step S5). If the answer is yes in step S4, the vehicle 1 is deemed to be traveling downhill, and the ECU 20 sets the upper limit driving force to the requested driving force (step S6). After executing step S5 or S6, the ECU 20 executes the vehicle speed limit processing using the switched upper limit driving force (step S7). Steps S5 to S7 are an example of the processing performed by the restriction processing unit.

[0029] Next, the ECU 20 determines whether the requested driving force is below the upper limit driving force and the vehicle speed is below the upper limit vehicle speed (step S8). If the answer is no in step S8, the ECU 20 continues the vehicle speed limit process (step S7). If the answer is yes in step S8, the ECU 20 stops the vehicle speed limit process (step S9).

[0030] In the above embodiment, the ECU 20 mounted on an engine vehicle is described as an example of a vehicle control device. The vehicle equipped with such an ECU may be a hybrid vehicle having an engine and a motor as driving power sources, or an electric vehicle having only a motor as driving power source.

[0031] While the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention as described in the claims. Description of the label

[0032] 1 vehicle 10 engines 20ECU (vehicle control device, restriction processing unit, switching unit).

Claims

1. A vehicle control device comprising: a restriction processing unit that, when the vehicle speed exceeds an upper limit speed, performs a vehicle speed restriction process, that is, restricts the vehicle speed to the upper limit speed by controlling a driving power source of the vehicle to restrict the driving force of the vehicle to the upper limit driving force; and A switching unit switches the upper limit vehicle speed from a first speed to a second speed higher than the first speed when the driving mode of the vehicle is switched to a track mode.

2. The vehicle control device according to claim 1, wherein: If the requested driving force for the vehicle when the vehicle speed exceeds the upper limit vehicle speed is smaller than the upper limit driving force, the restriction processing unit sets the upper limit driving force to the requested driving force when the vehicle speed exceeds the upper limit vehicle speed.

3. The vehicle control device according to claim 2, wherein: The restriction processing unit gradually reduces the upper limit driving force while the vehicle speed exceeds the upper limit vehicle speed, and gradually increases the upper limit driving force while the vehicle speed is equal to or lower than the upper limit vehicle speed.

4. The vehicle control device according to claim 3, wherein: The restriction processing unit stops the vehicle speed restriction processing when the requested driving force is equal to or less than the upper limit driving force and the vehicle speed is equal to or less than the upper limit vehicle speed.

5. The vehicle control device according to claim 4, wherein: The driving power source is an engine.

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