Control device for vehicle

Abstract

To provide a control device for a vehicle capable of suppressing discomfort felt by occupants during automatic driving.SOLUTION: In a control device for a vehicle 1 that is equipped with an engine (ENG) and a motor generator (MG) as a power source and can be driven manually or automatically, when the vehicle is at high speed and under high load, an increase rate of engine speed during automatic driving is set to be smaller than an increase rate of engine speed set during manual driving.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent document 1 discloses that in a control device for a vehicle equipped with an engine and a motor as a power source, when setting the rate of increase in engine speed, the rate of increase in engine speed is set to be higher than under normal conditions when the vehicle speed is high and the load is high. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5862684 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, in order to improve the feeling of sluggishness when accelerating at high speeds, the engine speed is increased early when a high load is required. However, in an autonomous vehicle, the occupants do not operate the vehicle, so the occupants do not feel the sluggishness when accelerating. Therefore, if the engine speed is increased early during autonomous driving without the occupants operating the vehicle, the engine noise may suddenly become easier to hear, the quietness may deteriorate, and the occupants may feel uncomfortable.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a vehicle control device that can suppress the feeling of discomfort felt by occupants during autonomous driving. [Means for solving the problem]

[0006] The present invention is a control device for a vehicle that has an engine and a motor as power sources and can be driven both manually and automatically, and is characterized in that when the vehicle is at high speed and under high load, the rate of increase in the engine speed during automatic driving is set to be smaller than the rate of increase in the engine speed set during manual driving. Effect of the Invention

[0007] In the present invention, since the increase in engine speed is suppressed during automatic driving, quietness can be maintained and discomfort felt by occupants can be suppressed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a vehicle according to an embodiment. [Diagram 2] FIG. 2 is a flow chart showing a process flow for setting the increase rate of the engine speed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle control device according to an embodiment of the present invention will be specifically described below. Note that the present invention is not limited to the embodiment described below.

[0010] 1 is a diagram illustrating a vehicle according to an embodiment of the present invention, the vehicle 1 including an engine (ENG) 2, a motor generator (MG) 3, a power transmission (T / M) 4, a battery 5, and a control device (ECU) .

[0011] The vehicle 1 is a hybrid system vehicle equipped with an engine 2 and a motor generator 3 as power sources. For example, the vehicle 1 is a parallel series type hybrid vehicle that can run only on the motor generator 3. In the vehicle 1, power output from the engine 2 is transmitted to the wheels via a power transmission device 4. The power transmission device 4 is configured to include a gear mechanism such as a transmission, and forms a power transmission path between the engine 2 and the wheels.

[0012] The motor generator 3 functions as an electric motor and a generator. The motor generator 3 is connected to the wheels via a power transmission device 4 so as to be capable of transmitting power. The motor generator 3 is driven by power supplied from a battery 5. When the power of the engine 2 is insufficient, the motor generator 3 is driven as an electric motor to supplement the power of the engine 2. When the power of the engine 2 is sufficient, the motor generator 3 is driven as a generator to store power in the battery 5. The engine 2 and the motor generator 3 are connected via a power split mechanism so as to be capable of transmitting power. In this case, the motor generator 3 may be configured to include two motor generators.

[0013] The control device 10 is an electronic control unit (ECU) that controls the vehicle 1. The control device 10 includes a processor and a memory. The processor is composed of a CPU and the like. The memory is a main storage device and is composed of a RAM, a ROM and the like. Signals from various sensors are input to the control device 10. Signals from a vehicle speed sensor that detects the vehicle speed, a signal from an accelerator opening sensor that detects the accelerator opening, a signal from a crank angle sensor that detects the crank angle of the crankshaft of the engine 2, a signal from a switch that switches between manual driving and automatic driving, and the like are input to the control device 10. Then, the control device 10 executes various controls based on the signals input from the various sensors. For example, the control device 10 executes automatic driving control that executes automatic driving of the vehicle 1. The control device 10 switches between automatic driving and manual driving based on a signal input from the switch. The control device 10 can determine whether the driving is automatic or manual (driving operation by the driver). In the automatic driving control, the control device 10 controls the engine 2, the motor generator 3 and the power transmission device 4 so that the power output from the engine 2 is transmitted to the wheels. The control device 10 includes an engine control unit (ENG-ECU) that controls the engine 2, and a motor control unit (MG-ECU) that controls the motor generator 3.

[0014] For example, the control device 10 controls the fuel injection, ignition timing, intake air amount, etc. of the engine 2 as an engine control unit. The control device 10 calculates the rate of increase in the engine speed based on a signal input from a crank angle sensor. When the driver requests acceleration during high-speed driving in manual driving, the control device 10 sets the rate of increase in the engine speed higher than the increase rate set during non-high-speed driving, and increases the engine speed faster than usual. During manual driving, the control device 10 determines whether or not there is a request for acceleration based on a signal input from an accelerator opening sensor in response to the driver's depression of the accelerator pedal.

[0015] In autonomous driving, the occupants of the vehicle 1 do not operate the vehicle, so the occupants do not feel any sluggishness. In other words, since no driving operation is involved during autonomous driving, an early increase in engine speed would lead to a deterioration in quietness and a sense of discomfort. Therefore, in the vehicle 1, early increase in engine speed during autonomous driving is stopped, and ensuring quietness is prioritized.

[0016] In this explanation, an example is given in which the control device 10 sets the maximum value of the rate of increase of the engine speed; however, when the vehicle 1 is operating at high speed and high load, the control device 10 controls the engine 2 so that the rate of increase of the engine speed follows the maximum value of the set rate of increase.

[0017] 2 is a flow chart showing a process flow for setting the increase rate of the engine speed. The control shown in FIG.

[0018] The control device 10 sets Nupmax as the maximum value of the rate of increase in engine speed (step S1). Nupmax is set to a maximum value that can satisfy acceleration in all driving states of the vehicle 1 (including manual driving and automatic driving). For example, Nupmax represents a maximum value that can satisfy an acceleration request in response to the driver's operation of the accelerator pedal during manual driving. The control device 10 sets a maximum value of the rate of increase in engine speed to prioritize the drivability of the driver, assuming manual driving.

[0019] The control device 10 judges whether the elapsed time of the engine operation is less than a predetermined time T1 (step S2). In step S2, it is judged whether the engine 2 has just been started. The control device 10 judges whether the elapsed time from the start of the engine operation is less than the predetermined time T1. The control device 10 judges whether the predetermined time T1 has not elapsed since the start of the engine 2 has been completed. The control device 10 has an internal timer, and when the start of the engine 2 is completed, the timer starts measuring time. The control device 10 refers to the timer and judges whether the measured time does not exceed the predetermined time T1. The predetermined time T1 is set to a time required for the engine 2 to increase to an engine speed at which the engine 2 can output the requested torque when the control device 10 requests the engine 2 to generate torque. For example, the predetermined time T1 is set to a range of 1 to 2 seconds.

[0020] If it is determined that the elapsed time of engine operation is not less than the predetermined time T1 (step S2: No), this control routine ends. In this case, it is determined that the engine 2 has not just been started.

[0021] If it is determined that the elapsed time of engine operation is less than the predetermined time T1 (step S2: Yes), the control device 10 determines whether the vehicle 1 is in a high-speed, high-load state (step S3). If the signal input from the vehicle speed sensor is equal to or greater than a predetermined vehicle speed and there is a request for acceleration of the vehicle 1, the control device 10 determines that the vehicle 1 is in a high-speed, high-load state. This acceleration request includes a system request during automatic driving and a driver request during manual driving (detection of accelerator pedal operation by the driver).

[0022] If it is determined that the vehicle 1 is not in a high-speed, high-load state (step S3: No), the control device 10 sets a first rate smaller than Nupmax as the maximum value of the engine speed increase rate (step S4). The first rate is a value set so that when the engine speed is increased immediately after the start of the engine 2, the driving force is reduced and the acceleration is reduced due to the power being taken by the inertia torque of the engine 2, and the driver does not feel uncomfortable when driving manually. The first rate is obtained in advance by experimental measurement of the relationship between the increase in engine speed and the decrease in driving force. After the process of step S4 is performed, this control routine ends.

[0023] If it is determined that the vehicle 1 is in a high-speed, high-load state (step S3: Yes), the control device 10 determines whether or not the vehicle is in an automatic driving mode (step S5). In step S5, it is determined whether or not the driving mode of the vehicle 1 is an automatic driving mode. The control device 10 determines whether or not the current driving mode is an automatic driving mode.

[0024] If it is determined that the vehicle is in an automatic driving state (step S5: Yes), the control device 10 sets the first rate as the maximum value of the rate at which the engine speed increases (step S6). In step S6, although the vehicle 1 is in a high-vehicle-speed, high-load state, priority is given to quietness because the vehicle is in an automatic driving state, and the first rate smaller than Nupmax is set as the maximum value of the rate at which the engine speed increases, and early increases in the engine speed are stopped. After the process of step S6 is performed, this control routine ends.

[0025] If it is determined that the vehicle is not in automatic operation (step S5: No), the control device 10 sets a second rate that is greater than the first rate as the maximum value of the rate at which the engine speed increases (step S7). The second rate is set to a value that is greater than the first rate and equal to or less than Nupmax. For example, the control device 10 is configured to set the second rate to a value equal to Nupmax, and to increase the engine speed early at high speed and high load during manual operation. After the process of step S7 is performed, this control routine ends.

[0026] As described above, according to the embodiment, during autonomous driving, the engine speed is not increased early and quietness is prioritized, thereby making it possible to suppress the passengers from feeling uncomfortable during autonomous driving. [Explanation of symbols]

[0027] 1 vehicle 2 Engine (ENG) 3 Motor generator (MG) 4 Power transmission device (T / M) 5 Battery 10. Control Unit (ECU)

Claims

[Claim 1] A control device for a vehicle that is equipped with an engine and a motor as a power source and can be driven manually or automatically, When the vehicle is at high speed and under high load, the rate at which the engine speed increases during automatic driving is set to be smaller than the rate at which the engine speed increases during manual driving. A vehicle control device comprising:

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