Vehicular control device

Abstract

To provide a technique for performing warm-up control suitable for a driving mode.SOLUTION: A vehicular control device can change execution contents of warm-up control for warming up a driving force source of a vehicle, and in an automatic driving mode, the execution contents of the warm-up control are changed from those in a manual driving mode.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a vehicle control device used in a vehicle having an autonomous driving mode and a manual driving mode. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there have been proposed techniques for determining whether or not an engine needs to be warmed up in a vehicle based on the engine coolant temperature and catalyst temperature (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-182335 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the inventors of the present disclosure have found that the necessity for warming up changes depending on whether the vehicle is running in a manual driving mode or an automatic driving mode. Therefore, it is desirable to perform warm-up control appropriate for the driving mode. [Means for solving the problem]

[0005] (1) According to one aspect of the present disclosure, there is provided a vehicle control device for use in a vehicle having an automatic driving mode and a manual driving mode as driving modes, the vehicle control device being capable of changing the content of warm-up control for warming up a driving power source of the vehicle, and in the automatic driving mode, changing the content of the warm-up control from the manual driving mode. According to this vehicle control device, it is possible to perform warm-up control taking into account the driving mode. (2) The vehicle control device may be configured to strengthen or weaken the warm-up control in the automatic driving mode in accordance with a driving plan for the vehicle in the automatic driving mode compared to the manual driving mode. According to this vehicle control device, it is possible to strengthen or weaken the warm-up control according to the driving plan in the automatic driving mode. (3) The vehicle control device may use at least one of a planned travel distance, a planned travel time, and a vehicle speed plan as the travel plan. According to this vehicle control device, it is possible to perform warm-up control taking into account the driving plan. (4) The vehicle control device may not perform the warm-up when a planned driving distance or a planned driving time in the autonomous driving mode is smaller than a preset threshold value. According to this vehicle control device, it is possible to improve fuel efficiency by eliminating the need for warming up. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is an explanatory diagram showing a configuration of a power transmission system of a vehicle. [Diagram 2] FIG. 4 is an explanatory diagram showing an example of a shift line diagram and a warm-up correction thereof; [Diagram 3] 4 is a flowchart showing a procedure for warm-up control according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] 1 is an explanatory diagram showing the configuration of a power transmission system of a vehicle 100. The vehicle 100 has an automatic driving mode and a manual driving mode as driving modes. The vehicle 100 is equipped with an engine 10, which is an internal combustion engine, a transmission 30, a differential gear 40, a plurality of drive wheels 50, and a vehicle control device 80. A drive shaft 11 of the engine 10 is connected to an input shaft 31 of the transmission 30. An output shaft 32 of the transmission 30 is connected to the differential gear 40.

[0008] The accelerator pedal 61 is provided with an accelerator opening sensor 71 that measures the accelerator opening ACC. The brake pedal 62 is provided with a brake pedal sensor 72 that measures the depression amount BRA of the brake pedal 62. The shift lever 63 is provided with a shift position sensor 73 that measures the shift position LP. The engine 10 is provided with a water temperature sensor 74 that measures the coolant temperature Tw. The transmission 30 is provided with an oil temperature sensor 75 that measures the oil temperature To of the hydraulic circuit. The drive wheels 50 are each provided with a wheel speed sensor 76. Measurement values ​​measured by the various sensors 71-76 are input to a vehicle control device 80.

[0009] The vehicle control device 80 includes a vehicle control unit 81, an automatic driving control unit 82, a driving mode setting unit 83, and a warm-up control unit 84. The vehicle control device 80 can be configured using one or more ECUs (Electronic Control Units). The ECU has a processor, a RAM, and a ROM, and a computer program is stored in the ROM. The functions of each of the units 81 to 84 can be realized by the processor executing a computer program stored in a non-volatile storage medium. Note that some of the functions of each of these units 81 to 84 may be realized by a hardware circuit.

[0010] The vehicle control unit 81 executes various controls such as drive control, brake control, and steering angle control for driving the vehicle 100. The vehicle control unit 81 is used in both automatic driving and manual driving.

[0011] The automatic driving control unit 82 executes automatic driving of the vehicle 100. Specifically, the automatic driving control unit 82 transmits a driving force command value indicating the driving force of the driving unit (engine and motor), a brake command value indicating the operating state of the brake mechanism, and a steering angle command value indicating the steering angle of the wheels to the vehicle control unit 81. The vehicle control unit 81 executes control of each of the mechanisms to be controlled according to the received command values.

[0012] In this disclosure, "autonomous driving" refers to driving in which all drive control, brake control, and steering angle control are performed automatically. In other words, the term "autonomous driving" includes autonomous driving from level 3 to level 5. Autonomous driving is performed according to a preset driving plan.

[0013] The driving mode setting unit 83 switches the driving mode of the vehicle 100 between a manual driving mode and an automatic driving mode. The driving mode can be switched, for example, by an occupant selecting an option displayed on a display. In addition, a driving mode switch may be received from an external device via wireless communication.

[0014] The warm-up control unit 84 determines whether or not warm-up is necessary based on the cooling water temperature Tw measured by the water temperature sensor 74 and the oil temperature To measured by the oil temperature sensor 75, and performs warm-up if warm-up is necessary. When the engine 10 is cold, such as immediately after starting the engine 10, friction in each part of the engine 10 and the transmission 30 is large compared to after warm-up is complete, so the driving force of the vehicle 100 decreases. Therefore, the warm-up control unit 84 performs warm-up of the engine 10 and the transmission 30 by correcting the shift line.

[0015] FIG. 2 is an explanatory diagram showing an example of a shift diagram and its warm-up correction. The horizontal axis is vehicle speed SP, and the vertical axis is accelerator opening ACC. The shift diagram is a diagram showing the shift timing according to the accelerator opening ACC and vehicle speed SP. The solid lines show upshift lines USn, USn+1 after warm-up is complete (i.e., when warm-up is not being performed). The area on the left side of the upshift line USn is the area of ​​the nth gear before the upshift, and the area on the right side is the area of ​​the n+1th gear after the upshift. Each upshift line US shows the condition for changing to a gear that is one gear higher (i.e., a gear with a smaller gear ratio) as the vehicle speed SP increases. Each upshift line US has a rising portion RU that is almost perpendicular to the horizontal axis of the vehicle speed SP, and a sloping portion SL that has a smaller angle with the horizontal axis than the rising portion RU. The dashed lines show the rising portion RUc of the upshift line for warm-up. The warm-up upshift line is corrected so that the rising portion RU moves toward the higher vehicle speed side. The correction amount Δ at this time is called the "warm-up correction amount Δ." Note that the slope portion SL remains substantially the same even after the warm-up correction. By correcting the upshift line US in this way, the engine 10 operates at a higher speed, making it possible to warm up the power transmission system including the engine 10. In addition, the driving force of the vehicle 100 can be increased, and the response of the gear shift can be improved.

[0016] The warm-up correction amount Δ is given by a function f of the coolant temperature Tw and the oil temperature To, for example, as shown in the following equation. Δ=f(Twt-Tw, Tot-To) …(1) Here, Twt is the threshold temperature for the cooling water temperature, and Tot is the threshold temperature for the oil temperature. Usually, the warm-up correction amount Δ is set so that it increases as the difference (Twt-Tw) between the cooling water temperature Tw and the threshold temperature Twt increases, and as the difference (Tot-To) between the oil temperature To and the threshold temperature Tot increases. When the cooling water temperature Tw is equal to or higher than the threshold temperature Twt and the oil temperature To is equal to or higher than the threshold temperature Tot, the warm-up correction amount Δ is zero. The threshold temperatures Twt and Tot are each set in the range of about 80°C to 90°C.

[0017] As described above, when the vehicle 100 is cold, such as immediately after the engine 10 is started, the driving force of the vehicle 100 is reduced. However, when the vehicle 100 runs in the automatic driving mode, even if the driving force is somewhat reduced, the passengers are unlikely to feel excessive discomfort, and therefore the need for warming up is lower than when the vehicle runs in the manual driving mode. As described below, in this embodiment, the warm-up control is performed taking this into consideration.

[0018] Fig. 3 is a flowchart showing a procedure for warm-up control in the embodiment. The process in Fig. 3 is executed, for example, at the start of the vehicle 100. The process in Fig. 3 may also be executed at regular time intervals after the start.

[0019] In step S10, the warm-up control unit 84 determines whether or not the warm-up conditions are met. The warm-up conditions are conditions under which it is desirable for the power transmission system including the engine 10 to warm up. Specifically, it is determined that the warm-up conditions are met when at least one of the cooling water temperature Tw and the oil temperature To is lower than the respective threshold temperatures Twt, Tot. If the warm-up conditions are not met, warm-up is not performed, and the process of FIG. 3 is terminated.

[0020] If it is determined that the warm-up conditions are met, the process proceeds to step S20, where the warm-up control unit 84 determines whether the current driving mode of the vehicle 100 is the automatic driving mode. If it is the manual driving mode, the process proceeds to step S30, where the warm-up control unit 84 executes a warm-up correction of the shift line for the normal driving mode. This warm-up correction is performed by setting the warm-up correction amount Δ in FIG. 2 described above to a value suitable for the normal driving mode.

[0021] If the current driving mode of the vehicle 100 is the automatic driving mode, the process proceeds to step S40, where the warm-up control unit 84 changes the warm-up correction of the shift line for the normal driving mode to that for the automatic driving mode. This change is performed so as to strengthen or weaken the implementation content of the warm-up control compared to the manual driving mode, depending on the driving plan in the automatic driving mode. The driving plan in the automatic driving mode can include a planned driving distance, a planned driving time, and a vehicle speed plan. It is preferable to change the implementation content of the warm-up control using at least one of the planned driving distance, the planned driving time, and the vehicle speed plan.

[0022] There are three possible methods for changing the warm-up correction of the shift line for the automatic driving mode, for example: <Changing method C1> The warm-up control is strengthened more than in the manual driving mode. That is, the warm-up correction amount Δ of the shift line is made larger than the value used in the manual driving mode. <Changing method C2> The warm-up control is weakened compared to the manual driving mode. That is, the warm-up correction amount Δ of the shift line is made smaller than the value used in the manual driving mode. <Changing method C3> Warm-up is not performed (warm-up is prohibited). In other words, the warm-up correction amount Δ of the shift line is set to zero.

[0023] The change method C1 is applied, for example, when the travel plan includes a plan for travel at high torque and high vehicle speed within a relatively short time from the start of the vehicle 100. Specifically, when the time when the torque is equal to or greater than the threshold torque and the vehicle speed is equal to or greater than the threshold vehicle speed is scheduled to occur within a threshold time from the start, it is preferable to apply the change method C1 and make the warm-up correction amount Δ of the shift line larger than the value used in the manual driving mode. Note that the phrase "make the warm-up correction amount Δ larger than the value used in the manual driving mode" means that when the cooling water temperature Tw and the oil temperature To are the same, the value of the warm-up correction amount Δ used in the automatic driving mode is made larger than that in the manual driving mode.

[0024] The change method C3 can be applied, for example, when the planned travel distance or planned travel time in the travel plan is smaller than a threshold value. In these cases, since there is little need to perform warm-up, it is preferable not to perform warm-up at all. In this way, fuel efficiency can be improved.

[0025] The change method C2 is applied when neither the change method C1 nor the change method C3 described above is applied. In the automatic driving mode, even if the driving force is somewhat reduced, there is a low possibility that the occupants will feel excessive discomfort, so the need for warming up is lower than when driving in the manual driving mode. Therefore, except when it is desired to strengthen the implementation of the warm-up control with the change method C1, it is preferable to improve fuel efficiency by weakening the implementation of the warm-up control compared to the manual driving mode. The change method C3 described above can also be considered as an example of weakening the implementation of the warm-up control compared to the manual driving mode. In the change method C3, the warm-up itself is not executed, so that fuel efficiency can be further improved.

[0026] As described above, in this embodiment, in the automatic driving mode, the warm-up control is changed from that in the manual driving mode, so that warm-up suitable for each driving mode can be executed.

[0027] In the above embodiment, the warm-up of a vehicle using an engine as a driving force source has been described, but the present disclosure is also applicable to warm-up of a vehicle using a battery and an electric motor as a driving force source. In this case, for example, when the battery temperature measured by a battery temperature sensor is equal to or higher than a preset threshold temperature, it is determined that the warm-up condition is satisfied. In addition, the warm-up control can be changed by changing the warm-up time, changing the warm-up intensity (amount of heat per unit time), or prohibiting warm-up. Battery warm-up can be applied to electric vehicles such as battery electric vehicles and hybrid vehicles having an engine and an electric motor.

[0028] Other forms: The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various forms without departing from the spirit of the present disclosure. For example, the present disclosure can be realized in the following aspects. The technical features in the above-mentioned embodiments corresponding to the technical features in each aspect described below can be appropriately replaced or combined in order to solve some or all of the problems of the present disclosure, or to achieve some or all of the effects of the present disclosure. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0029] The present disclosure may be realized in various forms other than a vehicle control device or a control method, for example, a computer program for controlling a vehicle, a non-transitory storage medium on which a computer program is recorded, or the like. [Explanation of symbols]

[0030] 10...engine, 11...drive shaft, 30...transmission, 31...input shaft, 32...output shaft, 40...differential, 50...drive wheels, 61...accelerator pedal, 62...brake pedal, 63...shift lever, 71...accelerator opening sensor, 72...brake pedal sensor, 73...shift position sensor, 74...water temperature sensor, 75...oil temperature sensor, 76...wheel speed sensor, 80...vehicle control device, 81...vehicle control unit, 82...automatic driving control unit, 83...driving mode setting unit, 84...warm-up control unit, 100...vehicle

Claims

1. A vehicle control device used in a vehicle having an automatic driving mode and a manual driving mode as driving modes, The vehicle control device is capable of changing the contents of warm-up control that warms up the driving force source of the vehicle, and in the automatic driving mode, the contents of the warm-up control are changed from those in the manual driving mode.

2. The vehicle control device according to claim 1, The vehicle control device strengthens or weakens the implementation of the warm-up control in the automatic driving mode compared to the manual driving mode, depending on a driving plan of the vehicle.

3. 3. The vehicle control device according to claim 2, The vehicle control device uses at least one of a planned travel distance, a planned travel time, and a vehicle speed plan as the travel plan.

4. The vehicle control device according to claim 1, The vehicle control device does not perform the warm-up when a planned driving distance or a planned driving time in the autonomous driving mode is smaller than a preset threshold value.

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