Hybrid vehicle control device

Abstract

To suppress deterioration in driveabililty during travelling in an automatic drive mode.SOLUTION: A hybrid vehicle control device is used for a hybrid vehicle including an engine outputting power for travelling and a motor outputting power for travelling, and controls the engine and the motor so as to travel in an automatic driving mode without depending on operation by a driver. In a case of travelling by motor travel travelling with power from the motor without the operation of the engine in the automatic driving mode, the engine is not started when a background noise level showing the magnitude of the background noise set on the basis of at least one parameter of a vehicle speed, a wiper operation state and noise in a cabin is smaller than a prescribed value.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a control device for a hybrid vehicle.

Background Art

[0002] Conventionally, as a control device for this type of hybrid vehicle, there has been proposed one that is used in a hybrid automobile including a traveling engine and a traveling motor, and starts the engine when the vehicle speed exceeds a set speed while traveling by the motor (see, for example, Patent Document 1). In this device, the set speed is made smaller in the manual driving mode (second driving mode) than in the automatic driving mode (first driving mode).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described control device for a hybrid vehicle, it is desired to further suppress shocks and noises and suppress a decrease in drivability in the automatic driving mode.

[0005] The control device for a hybrid vehicle of the present disclosure mainly aims to suppress a decrease in drivability during traveling in the automatic driving mode.

Means for Solving the Problems

[0006] The control device for a hybrid vehicle of the present disclosure has taken the following means to achieve the above main object.

[0007] The control device for a hybrid vehicle of the present disclosure A control device for a hybrid vehicle, which is used in a hybrid vehicle including an engine that outputs driving power for traveling and a motor that outputs driving power for traveling, and controls the engine and the motor so as to travel in an automatic driving mode that does not depend on the operation of a driver. When traveling by motor driving in which the vehicle travels with power from the motor without operating the engine in the automatic driving mode, if the noise level indicating the magnitude of the ambient noise set based on at least one parameter among the vehicle speed, the operating state of the wiper, and the sound inside the vehicle cabin is less than a predetermined value, the engine is not started. This is the gist.

Brief Description of Drawings

[0008]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0009] Next, a mode (embodiment) for carrying out the present disclosure will be described. FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 equipped with a control device for a hybrid vehicle as an embodiment of the present disclosure. As shown in FIG. 1, the hybrid vehicle 20 includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50 as a power storage device, a navigation device 60, a wiper 94, an in-vehicle microphone 95, an air conditioner 96, and a hybrid electronic control unit (hereinafter referred to as “HVECU”) 70.

[0010] The engine 22 is configured as an internal combustion engine that outputs power using fuel such as gasoline or diesel oil, and is connected to the carrier of the planetary gear 30 via the damper 28. The engine 22 is operationally controlled by an engine electronic control unit (hereinafter referred to as "engine ECU") 24. The engine ECU 24 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown in the figure. Various control signals for operationally controlling the engine 22 are output from the engine ECU 24 via the output ports. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θc from the crank position sensor 23 that detects the rotational position of the crankshaft 26 of the engine 22.

[0011] The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. The drive shaft 36, which is connected to the drive wheels 39a, 39b via the differential gear 38, is connected to the ring gear of the planetary gear 30.

[0012] The motor MG1 is configured as, for example, a synchronous generator motor. The motor MG2 is configured as, for example, a synchronous generator motor, and the rotor is connected to the drive shaft 36. The inverters 41, 42 are used to drive the motors MG1, MG2 and are connected to the battery 50 via the power line 54. The motors MG1, MG2 are rotationally driven by the motor electronic control unit (hereinafter referred to as "motor ECU") 40 by switching control of a plurality of switching elements (not shown) of the inverters 41, 42. The motor ECU 40 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, although not shown in the figure. Switching control signals and the like for the plurality of switching elements of the inverters 41, 42 are output from the motor ECU 40 via the output ports.

[0013] The battery 50 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery, and is connected to the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as "battery ECU") 52. The battery ECU 52 includes, although not shown, a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, and signals from various sensors necessary for managing the battery 50 are input via the input ports.

[0014] The navigation device 60 includes a main body 62 with a built-in control unit having a storage medium such as a hard disk storing map information and the like, input / output ports, and communication ports, a GPS antenna 64 for receiving information on the current location of the host vehicle, and a touch panel display 66 for displaying various information such as information on the current location of the host vehicle and the planned driving route to the destination and enabling the user to input various instructions. When a destination is set by the user's operation on the display 66, the main body 62 sets a planned driving route from the current location of the host vehicle to the destination based on the map information stored in the main body 62, the current location of the host vehicle from the GPS antenna 64, and the destination, and displays the set planned driving route on the display 66 to provide route guidance. The navigation device 60 is connected to the HVECU 70 via a communication port.

[0015] The wiper 94 is attached to the windshield (not shown) and wipes off water droplets adhering to the windshield. The wiper 94 performs operations such as intermittent operation, low-speed continuous operation, and high-speed continuous operation according to the driver's operation or a control signal from the HVECU 70. The in-vehicle microphone 95 is attached to the interior of the vehicle (not shown), collects the sound in the vehicle interior, converts it into an audio signal, and outputs it to the HVECU 70. The air conditioner 96 is configured as a device for conditioning the air in the vehicle interior and is controlled by the HVECU 70.

[0016] The HVECU 70 is configured as a microprocessor centered around a CPU. In addition to the CPU, it includes a ROM for storing processing programs, a RAM for temporarily storing data, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via the input port. For example, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the vehicle speed V from the vehicle speed sensor 88, the inter-vehicle distances D1, D2 between the host vehicle and other vehicles in front and behind from the surrounding recognition device 90, the switch signal from the automatic driving switch 92 that indicates the automatic driving mode, the wheel speeds Vwa to Vwd from the wheel speed sensors 98a to 98d that detect the wheel speeds of the driving wheels 39a, 39b and the driven wheels 39c, 39d, and the voice signal from the in-vehicle microphone 95. Here, the surrounding recognition device 90 is composed of a camera, a millimeter-wave radar, a quasi-millimeter-wave radar, an infrared laser radar, a sonar, etc. Various control signals such as the control signal to the wiper 94 and the control signal to the air conditioner 96 are output from the HVECU 70 via the output port. The HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port. The HVECU 70 calculates the change amount ΔVwa of the wheel speed as the change amount per unit time of the average wheel speed Vwav, which is the arithmetic mean of the wheel speeds Vwa to Vwd from the wheel speed sensors 98a to 98d.

[0017] In the control device used for the hybrid vehicle 20 of this embodiment configured in this way, the engine 22 and the motors MG1, MG2 are controlled to switch between motor driving (EV driving) that runs without the operation of the engine 22 and hybrid driving (HV driving) that runs with the operation of the engine 22 by the cooperative control of the HVECU 70, the engine ECU 24, and the motor ECU 40. Hereinafter, EV driving and HV driving in the normal driving mode (the automatic driving switch 92 is off) and EV driving and HV driving in the automatic driving mode (the automatic driving switch 92 is on) will be described.

[0018] In EV driving in the normal operation mode, the required torque Td* (required for the drive shaft 36) for driving is set based on the accelerator opening Acc from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. The torque commands Tm1*, Tm2* of the motors MG1, MG2 are set so that the required torque Td* is output to the drive shaft 36, and switching control of a plurality of switching elements of the inverters 41, 42 is performed so that the motors MG1, MG2 are driven by the torque commands Tm1*, Tm2*.

[0019] In HV driving in the normal operation mode, similar to EV driving in the normal operation mode, the required torque Td* is set, and the required power Pe* required for the engine 22 is set by subtracting the charge / discharge required power Pb* (positive value when discharging from the battery 50) based on the state of charge SOC of the battery 50 (the ratio of the charged capacity to the total capacity of the battery 50) from the required power Pd*. Then, the target rotational speed Ne* and target torque Te* of the engine 22, and the torque commands Tm1*, Tm2* of the motors MG1, MG2 are set so that the required power Pe* is output from the engine 22 and the required torque Td* is output to the drive shaft 36, and operation control (intake air amount control, fuel injection control, ignition control, etc.) of the engine 22 is performed so that the engine 22 is operated based on the target rotational speed Ne* and target torque Te*. The control of the inverters 41, 42 has been described above.

[0020] In the automatic driving mode, basically, EV driving and HV driving are performed in the same way as in the normal driving mode, except that the setting of the required torque Td* is different. In the automatic driving mode, regardless of whether it is EV driving or HV driving, based on the planned driving route from the navigation device 60, the current location of the host vehicle, map information (e.g., legal speed), and the inter-vehicle distances D1, D2 between the host vehicle and other vehicles in front of and behind the host vehicle from the surrounding recognition device 90 (when there are other vehicles around the host vehicle), the target vehicle speed V* is set, and the required torque Td* is set so that the vehicle speed V becomes the target vehicle speed V*. In the automatic driving mode, the wiper 94 is controlled to operate at an operating speed based on the amount of raindrops from a raindrop sensor (not shown) that detects raindrops attached to the windshield or the like and the vehicle speed V from the vehicle speed sensor 88. Also, the air conditioner 96 is controlled so that the temperature inside the vehicle cabin becomes the set temperature.

[0021] Next, the operation of the hybrid vehicle 20 of this embodiment configured in this way, particularly the operation when starting the engine 22 during EV driving in the automatic driving mode, will be described. FIG. 2 is a flowchart showing an example of a control routine executed by the HVECU 70. This routine is repeatedly executed at predetermined intervals (e.g., every few msec) during EV driving in the automatic driving mode.

[0022] When this routine is executed, the CPU of the HVECU 70 determines whether the normal start condition is satisfied (S100). Here, the normal start condition is satisfied when the required torque Td* reaches the start threshold value Tst or more. When the normal start condition is satisfied, the engine 22 is started (S210), and this routine ends. The engine 22 is started by motoring the engine 22 with the motor MG1 and starting the operation control of the engine 22 when the rotational speed Ne of the engine 22 reaches the start rotational speed Nst. After starting the engine 22, it shifts to HV driving.

[0023] When the normal start condition is not satisfied, the vehicle speed V from the vehicle speed sensor 88, the wiper state Sw, the in-vehicle sound level S, the air conditioning level Lac, and the wheel speed change amount ΔVwa are input (S110). The in-vehicle sound level S is obtained by analyzing the voice signal from the in-vehicle microphone 95 and inputting the obtained sound pressure. The wiper state Sw is input with the operating state (intermittent operation, low-speed continuous operation, high-speed continuous operation, etc.) obtained from the control signal to the wiper 94. The air conditioning level Lac is input with the operating state (weak, medium, strong, etc.) of the air conditioner 96 obtained from the control signal to the air conditioner 96. The wheel speed change amount ΔVwa is input with the value calculated based on the wheel speeds Vwa to Vwd from the wheel speed sensors 98a to 98d.

[0024] Subsequently, a first level L1 as the level of background noise due to vehicle speed is set based on the vehicle speed V (S120). The first level L1 is set to a larger value when the vehicle speed V is high than when it is low. This is based on the fact that the background noise is greater when the vehicle speed V is high than when it is low. Subsequently, a second level L2 as the level of background noise due to in-vehicle noise is set based on the in-vehicle noise level S (S130). The second level L2 is set to a larger value when the in-vehicle noise level S is high than when it is low. Further, a third level L3 as the level of background noise due to the operation of the wiper 94 is set based on the wiper state Sw (S140). The third level L3 is set to a larger value when the wiper 94 is operating continuously than when it is operating intermittently, and is also set to a larger value when the speed of the wiper 94 is high than when it is low. This is based on the fact that the operating noise is greater when the wiper 94 is operating continuously than when it is operating intermittently, and the operating noise is greater when the speed of the wiper 94 is high than when it is low. Then, a fourth level L4 as the level of background noise due to the operation of the air conditioner 96 is set based on the air conditioner level Lac (S150). The fourth level L4 is set to a larger value when the operating state of the air conditioner 96 is strong than when it is weak. This is based on the fact that the operating noise and the background noise are greater when the operating state of the air conditioner 96 is strong than when it is weak. Further, it is determined whether the road surface during driving is a wavy road (S160). This determination is made by determining that the road surface during driving is a wavy road when the change amount ΔVwa of the wheel speed is equal to or greater than a determination threshold for determining whether the road surface is a wavy road. When the road surface during driving is a wavy road, a fifth level L5 as the level of background noise due to the wavy road is set to the value 1 (S170). When the road surface during driving is not a wavy road, the fifth level L5 is set to the value 0 (S180). This is based on the fact that the background noise is greater when the road surface during driving is a wavy road than when it is not a wavy road.

[0025] Subsequently, the background noise level Lb is calculated as the sum of the first level L1, the second level L2, the third level L3, the fourth level L4, and the fifth level L5 (S190). Then, it is determined whether the calculated background noise level Lb is equal to or greater than a predetermined value Lbref (S200). The predetermined value Lbref is a threshold for determining whether the shock and sound when starting the engine 22 are likely to be recognized by the occupant. When the background noise level Lb is equal to or greater than the predetermined value Lbref, it is determined that the shock and sound when starting the engine 22 due to the background noise are difficult for the occupant to recognize, and the engine 22 is started (S210), and this routine ends. When the background noise level Lb is less than the predetermined value Lbref, the routine ends without starting the engine 22. Thus, when the background noise level Lb is less than the predetermined value Lbref, by not starting the engine 22, it is possible to suppress the shock and sound when starting the engine 22 from being recognized by the occupant. Thereby, it is possible to suppress a decrease in drivability during traveling in the automatic driving mode.

[0026] According to the hybrid vehicle 20 equipped with the control device of the embodiment described above, during EV traveling in the automatic driving mode, when the background noise level Lb set based on the vehicle speed V, the operating state of the wiper 94, the sound in the vehicle interior, the operating state of the air conditioner 96, and the wheel speeds Vwq to Vwd is less than the predetermined value Lbref, the engine 22 is not started, so it is possible to suppress a decrease in drivability during traveling in the automatic driving mode.

[0027] In the above-described embodiment, the background noise level Lb is set based on the vehicle speed V, the operating state of the wiper 94, the sound in the vehicle interior, the operating state of the air conditioner 96, and the wheel speeds Vwq to Vwd. Since the background noise level Lb may be set based on at least one parameter among the vehicle speed V, the operating state of the wiper 94, and the sound in the vehicle interior, it is not necessary to consider the operating state of the air conditioner 96 and the wheel speeds Vwq to Vwd.

[0028] In the above-described embodiment, the hybrid vehicle 20 is provided with the engine 22, the planetary gear 30, and the motors MG1 and MG2. However, any form of hybrid vehicle may be used as long as it includes an engine that outputs driving power and a motor that outputs driving power.

[0029] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems is an example for specifically explaining the form for implementing the invention described in the column of means for solving the problems in the embodiment. Therefore, it does not limit the elements of the invention described in the column of means for solving the problems. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the column of means for solving the problems.

[0030] As described above, the form for implementing the present disclosure has been explained. However, the present disclosure is not limited to such embodiments, and it goes without saying that it can be implemented in various forms without departing from the gist of the present disclosure.

Explanation of Reference Numerals

[0031] 20 Hybrid vehicle, 70 Hybrid electronic control unit.

Claims

[Claim 1] A control device for a hybrid vehicle including an engine that outputs power for driving and a motor that outputs power for driving, the control device controlling the engine and the motor so that the hybrid vehicle runs in an automatic driving mode without the operation of a driver, When the vehicle is traveling in the automatic driving mode by motor driving in which the vehicle is traveling by power from the motor without operating the engine, if a background noise level indicating the volume of background noise set based on at least one parameter of the vehicle speed, the operating state of the wipers, and the sound in the vehicle compartment is less than a predetermined value, the engine is not started. Hybrid vehicle control device.

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