Automobile

Abstract

To reduce a gear change shock experienced by a driver during autonomous driving.SOLUTION: An automobile comprises a control device that controls at least a drive device, an automatic gear change device, a brake device such that the automobile travels by autonomous driving using information from the surroundings recognition device that acquires information on surroundings of a vehicle. The control device prohibits the use of a predetermined low gear stage on a low-speed side in the automatic gear change device when the automobile travels by autonomous driving using a predetermined travel mode. As a result, the automobile can avoid a gear change from the predetermined gear stage or a gear change to the predetermined gear stage, and thereby a gear change shock experienced by the driver during autonomous driving can be reduced.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to an automobile, and more particularly to an automobile equipped with an automatic transmission and capable of automatic driving.

Background Art

[0002] Conventionally, as this type of automobile, during automatic driving control, when it is predicted that there is an acceleration / deceleration demand so that shifting is suppressed compared to manual driving, if the predicted acceleration / deceleration demand exists, when the upshift line after the change is on the high vehicle speed side and the downshift line after the change is on the high opening degree side, a technique has been proposed to change the shift line of the automatic transmission (see, for example, Patent Document 1). In this automobile, by the above-described control, during automatic driving, it is difficult to cause a sense of busyness or shock due to shifting of the automatic transmission.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described automobile, during automatic driving, although the shift line is changed so that the upshift line is on the high vehicle speed side and the downshift line is on the high opening degree side, since the low speed range, particularly the first gear range, is also used, a large shift shock occurs during an upshift from the first gear with a large gear ratio or a downshift to the first gear. During automatic driving, since the driver does not perform a driving operation, the sensory sensitivity to the shift shock increases, and thus a large shift shock is given to the driver.

[0005] The main object of the automobile of the present disclosure is to reduce the shift shock given to the driver during automatic driving.

Means for Solving the Problems

[0006] The motor vehicle of the present disclosure adopts the following means to achieve the above-mentioned main object.

[0007] The motor vehicle of the present disclosure is a motor vehicle provided with a control device that controls at least a drive device, an automatic transmission, and a brake device so as to travel by automatic driving using information from a surrounding recognition device that acquires information on the periphery of the vehicle, wherein when traveling by automatic driving using a predetermined driving mode, the control device prohibits the use of a predetermined low-speed gear on the low-speed side in the automatic transmission. This is the gist of the present invention.

[0008] The motor vehicle of the present disclosure is provided with a control device that controls at least a drive device, an automatic transmission, and a brake device so as to travel by automatic driving using information from a surrounding recognition device that acquires information on the periphery of the vehicle. When traveling by automatic driving using a predetermined driving mode, this control device prohibits the use of a predetermined low-speed gear on the low-speed side in the automatic transmission. As a result, when traveling by automatic driving using a predetermined driving mode, it is possible to avoid a shift shock during an upshift from the predetermined low-speed gear or a downshift to the predetermined low-speed gear. As a result, it is possible to reduce the shift shock given to the driver during automatic driving.

[0009] Here, the predetermined driving mode may be a driving mode other than the sports mode. The sports mode is based on the fact that it is a driving mode in which acceleration and shift shock are enjoyed. The predetermined low-speed gear may be the first gear. Since the shift shock during an upshift from the first gear and the shift shock during a downshift to the first gear are larger than the shift shocks of other gears, it is possible to avoid a larger shift shock by prohibiting the use of the first gear.

[0010] In the motor vehicle of the present disclosure, when traveling by automatic driving using the predetermined driving mode, the control device may permit a skip upshift in the automatic transmission. Examples of the skip upshift include, for example, an upshift from the second gear stage to the fourth gear stage and an upshift from the second gear stage to the fifth gear stage. By doing so, the number of gear shifts can be reduced and the shift shock can be reduced.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0012] 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 motor vehicle 20 as an embodiment of the present disclosure. As shown in the figure, the motor vehicle 20 of the embodiment includes a drive device 21, an automatic transmission 22, a brake device (braking device) 24, a steering device 26, and a main electronic control unit (hereinafter referred to as “main ECU”) 30.

[0013] The drive device 21 is configured as a device that rotationally drives the input shaft of the automatic transmission 22. For example, it may include an engine and a fuel tank to make the vehicle 20 a general engine-equipped vehicle, or include a motor, an inverter, and a battery to make the vehicle 20 an electric vehicle, or include an engine, a fuel tank, a motor, an inverter, and a battery to make the vehicle 20 a hybrid vehicle, or include a hydrogen tank, a fuel cell, a motor, and an inverter to make the vehicle 20 a fuel cell vehicle, etc.

[0014] The automatic transmission 22 includes, for example, a torque converter, a six-speed automatic transmission, and a hydraulic circuit (not shown). The torque converter is configured as a general fluid type transmission device, which can amplify and transmit the torque of the power on the input shaft to the input shaft of the automatic transmission, or transmit it directly without torque amplification. The automatic transmission is connected to the torque converter and the drive shaft 27, and has a plurality of planetary gears and a plurality of hydraulically driven friction engagement elements (clutches, brakes). Note that the drive shaft 27 is connected to the drive wheels 29a and 29b via a differential gear 28. The automatic transmission forms forward and reverse gears from the first speed to the sixth speed by engaging and disengaging a plurality of friction engagement elements, and transmits power between the torque converter and the drive shaft 27.

[0015] The drive device 21 and the automatic transmission 22 are under drive control by an electronic control unit for the drive device (hereinafter referred to as "drive ECU") 23. Although not shown, the drive ECU 23 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. Signals from various sensors necessary for operating and controlling the drive device 21 and signals from various sensors necessary for performing shift control of the automatic transmission 22 are input to the drive ECU 23 via the input ports. Further, various control signals for operating and controlling the drive device 21 and various control signals for driving and controlling the automatic transmission 22 are output from the drive ECU 23 via the output ports. The drive ECU 23 applies the accelerator opening Acc and the vehicle speed V to a shift diagram illustrated in FIG. 2 to set a target shift stage M*, and controls the automatic transmission so that the shift stage M of the automatic transmission of the automatic transmission 22 becomes the target shift stage M*. In FIG. 2, the solid line is a shift line for upshifting, and the broken line is a shift line for downshifting. Further, the drive ECU 23 calculates the rotational speed N of the drive shaft 27 based on the rotational position θ from a rotational position detection sensor (not shown) attached to the drive shaft 27. The drive ECU 23 communicates with the main ECU 30 via the communication port.

[0016] The brake device 24 is configured as a well-known hydraulically driven brake device, and is configured to be able to apply a braking force caused by a brake pedal force when the brake pedal 48 is depressed and a braking force caused by hydraulic pressure adjustment to the drive wheels 28a, 28b and the driven wheels 28c, 28d. The brake device 24 is under drive control by an electronic control unit for the brake (hereinafter referred to as "brake ECU") 25. Although not shown, the brake ECU 25 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. The brake ECU 25 controls the braking force caused by the brake pedal force by the brake device 24 and the braking force caused by hydraulic pressure adjustment. The brake ECU 25 communicates with the main ECU 30 via the communication port.

[0017] The steering device 26 has a steering wheel (not shown) and drive wheels 28a and 28b mechanically connected via a steering shaft, and is provided with a steering actuator. The steering device 26 steers the drive wheels 28a and 28b based on the driver's operation, and also steers the drive wheels 28a and 28b by driving the actuator based on a steering signal from the main ECU 30.

[0018] The main ECU 30 includes a microcomputer having a CPU 31, a ROM 32, a RAM 33, a flash memory 34, and input / output ports and communication ports (not shown). Signals from various sensors are input to the main ECU 30 via the input ports. Examples of the signals input to the main ECU 30 include an ignition signal from the ignition switch 40, the vehicle speed V from the vehicle speed sensor 41, the wheel speeds of each wheel from the wheel speed sensor 42, the acceleration α from the acceleration sensor 43, the yaw rate Yr from the yaw rate sensor 44, and the road surface gradient θr from the gradient sensor 45. Also, the accelerator opening Acc from the accelerator pedal position sensor 47 that detects the depression amount of the accelerator pedal 46 and the brake pedal position BP from the brake pedal position sensor 49 that detects the depression amount of the brake pedal 48 can be included. Furthermore, the driving mode DM from the driving mode switch 58 can be included. The driving mode DM includes, in addition to the normal mode, an eco mode that suppresses a certain amount of acceleration to improve fuel efficiency (or electricity cost), a sports mode that emphasizes acceleration more than fuel efficiency (or electricity cost), and the like.

[0019] From the main ECU 30, various control signals are output via the output ports. Examples of the control signals output from the main ECU 30 include the control signal to the steering device 26, the air conditioning control signal to the air conditioning device 29, the display control signal to the display device 70, and the communication control signal to the communication device 72. As described above, the main ECU 30 communicates with the drive ECU 23, the brake ECU 25, etc. via the communication port. Also, the main ECU 30 communicates with the electronic control unit for shifting (hereinafter referred to as "shift ECU") 50, the electronic control unit for peripheral recognition (hereinafter referred to as "peripheral recognition ECU") 55, and the navigation device 60 via the communication port.

[0020] Although not shown, the shift ECU 50 includes a microcomputer having a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. A shift position signal from a shift position sensor 52 that detects the operation position of the shift lever 51 is input to the shift ECU 50 via the input port. Examples of the shift position include the parking position (P range), the neutral position (N range), the drive position (D range), the reverse position (R range), etc. The shift ECU 50 is connected to the peripheral recognition ECU 55 via the communication port in addition to the main ECU 30, and sets the shift position based on the shift position signal from the shift position sensor 52 and the control signal from the peripheral recognition ECU 55, or transmits the set shift position to the main ECU 30.

[0021] The surrounding recognition ECU 55 includes, although not shown, a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. Various signals are input to the surrounding recognition ECU 55 via the input ports. Examples of the signals input to the surrounding recognition ECU 55 include signals indicating information about the host vehicle and its surroundings from the surrounding recognition device 56 (e.g., inter-vehicle distances D1 and D2 between the host vehicle and other vehicles in front of and behind the host vehicle, and the running position of the host vehicle in the lane on the road surface), and an automatic driving mode signal from the automatic driving switch 57. Examples of the surrounding recognition device 56 include a camera, millimeter-wave radar, quasi-millimeter-wave radar, infrared laser radar, sonar, and the like. The automatic driving switch 57 is a switch for switching between a fully automatic driving mode in which all driving operations are automatically performed, a semi-automatic driving mode in which some driving operations are performed by the driver, and a manual driving mode in which the driver performs the driving operations. Examples of the semi-automatic driving mode include adaptive cruise control. As described above, the surrounding recognition ECU 55 communicates with the main ECU 30 and the shift ECU 50 via the communication ports.

[0022] The navigation device 60 includes a main body 62 with a built-in control unit, a GPS antenna 64 that receives information about the current location of the host vehicle, and a display 66. The control unit of the main body 62 has a storage medium (such as a hard disk or SSD) in which map information and the like are stored, an input / output port, and a communication port. In the map information, service information (such as tourist information and parking lots) and road information for each driving section (such as between traffic lights and intersections) are stored as a database. The road information includes distance information, width information, number of lanes information, regional information (urban areas and suburbs), type information (general roads and highways), gradient information, legal speed, number of traffic lights, turning radius of each curve, and the like. The display 66 is configured as a touch panel type display that can display various information such as information about the current location of the host vehicle and the planned driving route to the destination, and allows the user to input various instructions. When the destination is set by the user's operation of the display 66, the main body 62 of the navigation device 60 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.

[0023] Next, the operation of the motor vehicle 20 of the embodiment configured in this way, particularly the operation when driving automatically using the fully automatic driving mode or the semi-automatic driving mode, will be described. FIG. 3 is a flowchart showing an example of a shift selection process related to the shifting of the automatic transmission 22 executed by the main ECU 30. In the motor vehicle 20 of the embodiment, when driving automatically using the fully automatic driving mode or the semi-automatic driving mode, the main ECU 30 calculates the torque to be output to the drive shaft 27 for driving according to the target vehicle speed V*, vehicle speed V, acceleration α, inter-vehicle distance from the preceding vehicle, etc., and sets it as the required torque T*, and controls the drive device 21 and the automatic transmission 22 so that the set required torque T* is output to the drive shaft 27.

[0024] When the shift selection process is executed, the main ECU 30 determines whether or not it is in the automatic driving state (step S100) and whether or not the driving mode is the sports mode (step S110). Here, the automatic driving includes not only the automatic driving using the automatic driving mode but also the automatic driving using the semi-automatic driving mode. When it is not in the automatic driving state (when manually driving) or when the driving mode is the sports mode even during automatic driving, the normal shift process using the shift diagram of FIG. 2 is selected (step S120), and this process ends.

[0025] On the other hand, when it is determined in step S100 that it is in the automatic driving state and it is determined in step S110 that the driving mode is not the sports mode, the process of prohibiting the use of the first gear stage among the gear stages of the automatic transmission 22 is selected (step S130), and this process ends. As the process of prohibiting the shift to the first gear stage, as shown in the shift diagram illustrated in FIG. 4, the shift control is performed using the gear stages from the second gear stage to the sixth gear stage. Since the shift shock generated when shifting from the first gear stage with a large gear ratio to the second gear stage or when shifting from the second gear stage to the first gear stage is larger than the shift shock generated when shifting to other gear stages, during automatic driving without a driving operation, the sensory sensitivity is higher than during manual driving, so the driver will feel the shift shock more strongly. During automatic driving in the sports mode, the use of the first gear stage is prohibited in order to reduce such a shift shock given to the driver. On the other hand, in the automatic driving in the sports mode, since the driver is in a driving mode that enjoys a large acceleration and a shift shock, the shift from the first gear stage with a large shift shock and the shift to the first gear stage are allowed.

[0026] In the automobile 20 of the embodiment described above, when it is in the automatic driving state and the driving mode is not the sports mode, the use of the first gear stage among the gear stages of the automatic transmission 22 is prohibited. Thereby, the shift shock given to the driver during automatic driving can be reduced.

[0027] In the motor vehicle 20 of the embodiment, when it is in automatic driving and the driving mode is not the sports mode, the use of the first gear among the gear positions of the automatic transmission 22 is prohibited. However, it is also possible to permit skip upshifting. The gearshift selection process in this case is shown in FIG. 5. In the gearshift selection process of FIG. 5, when it is determined in step S100 that it is in automatic driving and it is determined in step S110 that the driving mode is not the sports mode, a process of prohibiting the use of the first gear among the gear positions of the automatic transmission 22 is selected (step S130), skip upshifting is permitted (step S140), and this process is terminated. Since the use of the first gear is prohibited, an upshift from the second gear to the fourth gear is performed for skip upshifting. An example of a gearshift diagram when prohibiting the shift to the first gear and permitting skip upshifting from the second gear to the fourth gear is shown in FIG. 6. In FIG. 6, not only skip upshifting from the second gear to the fourth gear but also skip downshifting from the fourth gear to the second gear is performed. That is, the gearshift diagram of FIG. 6 is equivalent to the case where the use of the first gear and the third gear is prohibited. In this way, by performing skip upshifting, the number of gearshifts can be reduced and the shift shock can be reduced.

[0028] In the motor vehicle 20 of the embodiment, the drive ECU 23 is used to control the drive device 21 and the automatic transmission 22, and the brake ECU 25 is used to control the brake device 24. However, all or part of the functions of the drive ECU 23 and the brake ECU 25 may be performed by the main ECU 30.

[0029] 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 will be described. In the embodiment, the surrounding recognition device 56 corresponds to the "surrounding recognition device", the drive device 21 corresponds to the "drive device", the automatic transmission 22 corresponds to the "automatic transmission", the brake device 24 corresponds to the "brake device", and the drive ECU 23, the brake ECU 25, the main ECU 30, etc. correspond to the "control device".

[0030] Note that the correspondence between the main elements of the embodiments and the main elements of the invention described in the column of means for solving the problems is an example for specifically explaining the mode for carrying out the invention described in the column of means for solving the problems in the embodiments. 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 embodiments are merely specific examples of the invention described in the column of means for solving the problems.

[0031] As described above, the embodiments for carrying out the present invention have been described using the embodiments. However, the present invention is not limited to such embodiments at all, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention.

Industrial Applicability

[0032] The present invention can be used in the manufacturing industry of automobiles and the like.

Explanation of Reference Numerals

[0033] 20 Automobile, 21 Driving device, 22 Automatic transmission device, 23 Electronic control unit for driving device (Drive ECU), 24 Brake device, 25 Electronic control unit for brake device (Brake ECU), 26 Steering device, 27 Drive shaft, 28 Differential gear, 29a, 29b Driving wheels, 29c, 29d Driven wheels, 30 Main electronic control unit (Main ECU), 31 CPU, 32 ROM, 33 RAM, 34 Flash memory, 40 Ignition switch, 41 Vehicle speed sensor, 42 Wheel speed sensor, 43 Acceleration sensor, 44 Yaw rate sensor, 45 Gradient sensor, 46 Accelerator pedal, 47 Accelerator pedal position sensor, 48 Brake pedal, 49 Brake pedal position sensor, 50 Shift ECU, 51 Shift lever, 52 Shift position sensor, 55 Electronic control unit for peripheral recognition device (Peripheral Recognition ECU), 56 Peripheral recognition device, 57 Automatic driving switch, 58 Driving mode switch, 60 Navigation device, 62 Body, 64 GPS antenna, 66 Display, 70 Display device, 72 Communication device.

Claims

1. An automobile comprising a control device that controls at least a drive device, an automatic transmission, and a brake device so as to travel by automatic driving using information from a surrounding recognition device that acquires information around the vehicle, wherein when traveling by automatic driving using a predetermined driving mode, the control device prohibits use of a predetermined low-speed gear on the low-speed side in the automatic transmission. An automobile characterized by this.

2. The automobile according to Claim 1, wherein the predetermined driving mode is a driving mode other than a sports mode, and the predetermined low-speed gear is the first gear. An automobile.

3. The automobile according to Claim 1 or 2, wherein when traveling by automatic driving using the predetermined driving mode, the control device permits skip upshifting in the automatic transmission. An automobile.

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