Vehicle control system

Abstract

To provide a controller of a vehicle which can exhibit travel performance of the vehicle at a circuit mode.SOLUTION: A controller of a vehicle comprises: a limit processing part which executes vehicle speed limit processing to control, when vehicle speed exceeds an upper limit speed, a traveling power source of the vehicle to limit driving force of the vehicle to be the upper limit drive force so that the vehicle speed is limited to be the upper limit speed; and a changeover part which switches, when a travel mode of the vehicle is switched to a circuit mode, the upper limit speed from a first speed to a second speed higher than the first speed.SELECTED DRAWING: Figure 2

Description

[[Technical Field]]

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

[0002] There are vehicles capable of switching a travel mode to a circuit mode (see, for example, Patent Document 1). [[Prior Art Documents]] [[Patent Documents]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Application Publication No. 2015-199382 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] When a vehicle speed exceeds an upper limit vehicle speed, the vehicle speed can be limited to the upper limit vehicle speed by limiting the driving force of the vehicle to a predetermined upper limit driving force. For example, when the travel mode is switched to the circuit mode, if the vehicle speed is limited to the same upper limit vehicle speed as when the travel mode is set to a mode other than the circuit mode, there is a possibility that the traveling performance of the vehicle cannot be exhibited.

[0005] Accordingly, an object of the present invention is to provide a vehicle control device capable of exhibiting the traveling performance of a vehicle in the circuit mode. [[Means for Solving the Problem]]

[0006] The above object is achieved by a vehicle control device comprising: a restriction processing unit that executes vehicle speed restriction processing for restricting the vehicle speed to the upper limit vehicle speed by controlling a travel power source of the vehicle to restrict the driving force of the vehicle to an upper limit driving force when the vehicle speed of the vehicle exceeds the upper limit vehicle speed; 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 travel mode of the vehicle is switched to the circuit mode.

[0007] If the required driving force to the vehicle when the vehicle speed exceeds the upper limit vehicle speed is less than the upper limit driving force, the limiting unit may set the upper limit driving force to the required driving force when the vehicle speed exceeds the upper limit vehicle speed.

[0008] While the vehicle speed exceeds the upper limit vehicle speed, the limiting unit may gradually reduce the upper limit driving force, and while the vehicle speed is less than or equal to the upper limit vehicle speed, the limiting unit may gradually increase the upper limit driving force.

[0009] If the requested driving force is less than or equal to the upper limit driving force and the vehicle speed is less than or equal to the upper limit vehicle speed, the limiting processing unit may stop the vehicle speed limiting process.

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

[0011] According to the present invention, a vehicle control device can be provided that enables the vehicle to perform at its best in circuit mode. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of the vehicle's configuration. [Figure 2] This is a timing chart illustrating vehicle speed limit processing. [Figure 3] This is a timing chart illustrating the speed limiting process when driving downhill. [Figure 4] This is a flowchart illustrating vehicle speed limit processing. [Modes for carrying out the invention]

[0013] [Vehicle Outline] Figure 1 is a schematic diagram showing the general configuration of vehicle 1. Vehicle 1 is equipped with an engine (ENG) 10, a torque converter (T / C) 12, and a stepped automatic transmission (A / T) 14. The engine 10 is a gasoline engine, but it may also be a diesel engine. The torque converter 12 is connected to the crankshaft 11 of the engine 10. The 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. The output shaft 15 of the automatic transmission 14 is connected to a differential gear 16, which is the final reduction gear. The left and right axles 17 are connected to the differential gear 16. The driving force transmitted to the output shaft 15 is transmitted to the drive wheels 18 via the axles 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 system and functionally implements the limiting processing unit and switching unit, which will be described in more detail later.

[0015] The ECU 20 is connected to a crank angle sensor 21, an air flow meter 23, an accelerator pedal position sensor 24, a mode selector switch 25, and a vehicle speed sensor 26, and the output values ​​of these sensors are input. The crank angle sensor 21 detects the rotational speed of the engine 10. The air flow meter 23 detects the amount of intake air for the engine 10. The accelerator pedal position sensor 24 detects the accelerator pedal position, which is the degree to which the accelerator pedal is opened. The mode selector switch 25 can switch between driving modes, which will be described later. The vehicle speed sensor 26 detects the driving speed of the vehicle 1.

[0016] The ECU 20 calculates the required torque for the engine 10 based on the engine speed, intake air volume, and accelerator opening detected by the sensors mentioned above. The ECU 20 controls the fuel injection amount, intake air volume, and ignition timing of the engine 10 so that the output torque of the engine 10 becomes the required 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 becomes the target idle speed.

[0017] The ECU 20 can switch the driving mode to one of the following: Normal mode, Sport mode, Eco mode, or Circuit mode. The driver can switch the driving mode to Normal mode, Sport mode, or Eco mode by operating the mode selector switch 25. For Circuit mode, for example, if Vehicle 1 is at a race track, the driver can switch the driving mode to Circuit mode by operating a mobile device such as a smartphone. When the driving mode is switched to Circuit mode, the control map of Vehicle 1 is switched to a control map that prioritizes driving performance corresponding to Circuit mode. As a result, the driving performance of Vehicle 1 is improved compared to driving modes other than Circuit mode. Note that switching to Circuit mode may also be done using the mode selector switch 25 as described above.

[0018] The ECU 20 performs a vehicle speed limiting process that restricts the vehicle speed to an upper limit when predetermined conditions are met. Specifically, when the vehicle speed of vehicle 1 exceeds the upper limit, the ECU 20 controls the engine 10, which is the power source for vehicle 1, to limit the driving force of vehicle 1 to a predetermined upper limit. More specifically, the torque requested to the engine 10 is limited so that the driving force of vehicle 1 becomes the upper limit, and the fuel injection amount and intake air amount are limited so that the actual torque of the engine 10 becomes the requested torque. This limits the vehicle speed to the upper limit. Details of the vehicle speed limiting process are described below.

[0019] [Vehicle speed limit processing] FIG. 2 is a timing chart illustrating vehicle speed limiting processing. FIG. 2 shows changes in the on / off state of a circuit mode, actual vehicle speed, upper limit vehicle speed, actual driving force, upper limit driving force, and requested driving force. The requested driving force is a requested value of the driving force of the vehicle 1 calculated based on an accelerator opening degree, an operating state of an engine 10, and the like.

[0020] When the traveling mode is switched to the circuit mode, the upper limit vehicle speed is switched to a higher speed side (time t1). Specifically, the upper limit vehicle speed is switched from speed Va to speed Vb that is higher than speed Va. As described above, in the circuit mode, traveling at a speed higher than speed Va and lower than speed Vb is enabled. Thus, the traveling performance of the vehicle 1 can be exhibited in the circuit mode.

[0021] When the requested driving force increases as the accelerator opening degree is increased by the driver, the actual driving force and the actual vehicle speed increase accordingly (time t2). When the actual vehicle speed exceeds the upper limit vehicle speed Vb, the upper limit driving force is set from driving force Fa to driving force Fb on the lower driving force side, and the vehicle speed limiting processing is executed (time t3). Accordingly, regardless of the requested driving force, the actual driving force is limited to the upper limit driving force Fb. Here, driving force Fb is set to a driving force that causes the vehicle speed to converge to the upper limit vehicle speed Vb. In this way, the actual vehicle speed is limited to speed Vb, and safety is ensured.

[0022] Further, 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 equal to or lower than 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. Therefore, the actual vehicle speed gently converges to speed Vb. Accordingly, the occurrence of shock in the vehicle 1 due to the execution of the vehicle speed limiting processing is suppressed.

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

[0024] Figure 3 is a timing chart illustrating the vehicle speed limiting process when driving downhill. In circuit mode, when vehicle 1 is driving downhill, the actual vehicle speed increases, and the required driving force decreases as the driver reduces the amount the accelerator pedal is pressed (time t1).

[0025] When the actual vehicle speed exceeds speed Vb, the vehicle speed limiting process is executed (time t2). Here, the requested driving force is less than the upper limit driving force, which is the driving force Fb. In this case, we will explain as a comparative example the case in which the upper limit driving force is set to the driving force Fb and the vehicle speed limiting process is executed. In the comparative example, since the actual driving force is less than the driving force Fb, the actual driving force is not limited, and the vehicle speed is not limited either. The upper limit driving force gradually decreases from the driving force Fb, and when the upper limit driving force becomes less than or equal to the actual driving force, the actual driving force is limited (time t3). Thus, there is a time lag between when the actual vehicle speed exceeds speed Vb and when the limitation of the actual driving force begins. For this reason, it takes time for the actual vehicle speed to be limited to speed Vb.

[0026] In this embodiment, if the required driving force is less than the driving force Fb when the actual vehicle speed exceeds speed Vb, the upper limit of the driving force is set to the required driving force (time t2). As a result, the limitation of the actual driving force begins at approximately the same time that the actual vehicle speed exceeds speed Vb. This limits the actual vehicle speed to speed Vb at an early stage.

[0027] Figure 4 is a flowchart illustrating the vehicle speed limiting process. This control is repeated continuously as long as the ignition is on. The ECU 20 determines whether the driving mode has been switched to circuit mode (step S1). If the answer in step S1 is No, this control terminates. If the answer in step S1 is Yes, the upper limit vehicle speed is switched from speed Va to speed Vb (step S2). Step S2 is an example of the process executed by the switching unit. Next, the ECU 20 determines whether the vehicle speed has exceeded the upper limit vehicle speed, speed Vb (step S3). If the answer in step S3 is No, this control terminates.

[0028] If the answer in step S3 is Yes, the ECU 20 determines whether the requested driving force is less than the upper limit driving force Fb (step S4). If the answer in step S4 is No, the ECU 20 sets the upper limit driving force to the driving force Fb (step S5). If the answer in step S4 is Yes, the vehicle 1 is assumed to be traveling downhill, and the ECU 20 sets the upper limit driving force to the requested driving force (step S6). After the execution of step S5 or S6, the ECU 20 performs vehicle speed limiting processing based on the switched upper limit driving force (step S7). Steps S5 to S7 are examples of processes performed by the limiting processing unit.

[0029] Next, the ECU20 determines whether the requested driving force is less than or equal to the upper limit driving force and whether the vehicle speed is less than or equal to the upper limit vehicle speed (step S8). If the answer in step S8 is No, the ECU20 continues the vehicle speed limiting process (step S7). If the answer in step S8 is Yes, the ECU20 stops the vehicle speed limiting process (step S9).

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

[0031] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of Symbols]

[0032] 1 vehicle 10 Engines 20. ECU (Vehicle control unit, limiting unit, switching unit)

Claims

1. A speed limiting processing unit that, when the vehicle speed exceeds the upper limit speed, controls the vehicle's power source to limit the vehicle's driving force to the upper limit driving force, thereby limiting the vehicle speed to the upper limit speed, and The vehicle includes a switching unit that, when the vehicle's driving mode is switched to circuit mode, switches the upper limit vehicle speed from a first speed to a second speed higher than the first speed, A vehicle control device wherein, when the vehicle speed exceeds the upper limit vehicle speed, the requested driving force to the vehicle is less than the upper limit driving force, the limiting processing unit sets the upper limit driving force to the requested driving force when the vehicle speed exceeds the upper limit vehicle speed.

2. The vehicle control device according to claim 1, wherein while the vehicle speed exceeds the upper limit vehicle speed, the limiting processing unit gradually reduces the upper limit driving force, and while the vehicle speed is less than or equal to the upper limit vehicle speed, the limiting processing unit gradually increases the upper limit driving force.

3. The vehicle control device according to claim 2, wherein when the requested driving force is less than or equal to the upper limit driving force and the vehicle speed is less than or equal to the upper limit vehicle speed, the limiting processing unit stops the vehicle speed limiting processing.

4. The vehicle control device according to claim 3, wherein the aforementioned power source for driving is an engine.

Images