JP2020104761A - Vehicle control device - Google Patents

Abstract

To provide a vehicle control device capable of improving controllability of a vehicle during parking travelling.SOLUTION: A vehicle control device 70 controls a travelling operation of a vehicle including an engine, a transmission for changing speed of the rotation by the driving of the engine and transmitting it to wheels, and includes a parking command part 601 for commanding the travel in a parking mode for allowing a vehicle to enter a parking place or to exit from the parking place, and a transmission control part 604 for controlling the transmission ratio of the transmission. When travelling in a parking mode is commanded by the parking command part 601, the transmission control part 604 makes the maximum transmission ratio of the transmission smaller than the time when the travel in the parking mode is not commanded.SELECTED DRAWING: Figure 7

Description

The present invention relates to a vehicle control device that controls an operation of a vehicle when it is parked.

When a vehicle enters (enters) the parking lot or exits (exits) from the parking lot, the shift range is set to the drive range while the engine is rotating at the idle speed by not operating the accelerator pedal of the driver. Generally, a vehicle is run by a creep phenomenon while operating a foot brake (for example, refer to Patent Document 1). Since such parking traveling is performed at a low speed, the automatic transmission is usually switched to the low gear.

Patent Document 1: JP-A-5-60224

However, when the automatic transmission is switched to the low gear, the drive torque during parking traveling due to the creep phenomenon becomes too large and the controllability of the vehicle deteriorates.

One aspect of the present invention is a vehicle control device that controls a traveling operation of a vehicle that includes an engine and a transmission that shifts rotation by driving the engine and transmits the rotation to wheels. A parking command unit for instructing traveling in a parking mode for leaving the parking lot and a transmission control unit for controlling the gear ratio of the transmission are provided. When the parking command unit issues a command to drive the vehicle in the parking mode, the transmission control unit reduces the maximum gear ratio of the transmission as compared with when the parking mode command is not issued.

According to the present invention, the controllability of the vehicle during parking can be improved.

The figure which shows roughly the structure of some driving|running drive systems of the vehicle to which the vehicle control apparatus which concerns on embodiment of this invention is applied. The figure which shows the transmission path of the torque when the 1st speed stage of the vehicle of FIG. 1 is established. The figure which shows the transmission path of the torque when the 3rd speed stage of the vehicle of FIG. 1 is established. 1 is a block diagram schematically showing an overall configuration of a vehicle control system having a vehicle control device according to an embodiment of the present invention. The top view which shows an example of the driving|running|working operation|movement of the vehicle by the vehicle control system of FIG. The figure which shows the relationship between engine speed and creep torque. The figure which shows an example of the operating characteristic obtained when creeping at the 1st speed stage. The block diagram showing the important section composition of the vehicle control device concerning the embodiment of the present invention. 8 is a flowchart showing an example of processing executed by the controller of FIG. 7. The time chart which shows an example of operation by the vehicle control device concerning the embodiment of the present invention.

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram schematically showing a configuration of a part (mainly a transmission 1) of a traveling drive system of a vehicle 100 to which a vehicle control device according to an embodiment of the present invention is applied. Vehicle 100 is configured as a hybrid vehicle including engine 2 and electric motor 3, for example.

A clutch mechanism C that transmits or does not transmit the torque of the engine 2 to the transmission 1 is provided between the transmission 1 and the engine 2. The clutch mechanism C is composed of, for example, a wet dual clutch, and has a first clutch C1 and a second clutch C2. The clutch mechanism C can also be configured by a dry dual clutch.

The transmission 1 is, for example, a stepped transmission, and includes a gear mechanism 10 that shifts the rotation of at least one of the engine 2 and the electric motor 3 input to the transmission 1 at a gear ratio according to a speed stage. The torque output via the gear mechanism 10 is transmitted to the drive wheels via an operating gear mechanism (not shown), a drive shaft, etc., so that the vehicle travels. The torque of the engine 2 may be output to the transmission 1 via the torque converter.

The gear mechanism 10 is arranged substantially parallel to each other and has a plurality of rotating shafts rotatably supported, that is, a first main input shaft 11, a second main input shaft 12, an auxiliary input shaft 13, an output shaft 14, and an idle shaft. It has a shaft 15 and a reverse shaft 16. The second main input shaft 12 is formed coaxially with the first main input shaft 11 and hollow so as to surround the first main input shaft 11. The transmission 1 is, for example, an automatic transmission having seven forward speeds and one reverse speed.

The electric motor 3 is composed of, for example, a three-phase DC brushless motor, and includes a rotor 3a rotatably supported in the housing of the electric motor 3 (not shown), and a stator 3b arranged around the rotor 3a and fixed to the housing. Have. One end of the first main input shaft 11 is connected to the rotor 3a of the electric motor 3, and the first main input shaft 11 can rotate integrally with the rotor 3a. The stator 3b has a coil wound around a stator core, and the coil is electrically connected to the battery via the power drive unit. The operation of the power drive unit is controlled by the controller.

The other end of the first main input shaft 11 is connected to the output shaft 2a of the engine 2 via the first clutch C1, and the first main input shaft 11 and the output shaft 2a are connected in accordance with the connection and disconnection of the first clutch C1. Are bound or blocked. That is, when the first clutch C1 is connected, the first main input shaft 11 and the output shaft 2a are coupled, and the torque from the engine 2 is input to the first main input shaft 11. On the other hand, when the first clutch C1 is disengaged, the first main input shaft 11 and the output shaft 2a are disengaged, and the torque input from the engine 2 is interrupted.

The first clutch C1 is a clutch for odd gears, and the first main input shaft 11 includes a first speed drive gear 21, a third speed drive gear 23, a seventh speed drive gear 27, and a fifth speed drive gear 25. , Are arranged in this order from the electric motor 3 side. These drive gears 21, 23, 25 and 27 are supported on the outer peripheral surface of the first main input shaft 11 via bearings so as to be rotatable relative to the first main input shaft 11. The first speed drive gear 21 and the third speed drive gear 23 are integrally rotatable. A planetary gear mechanism 20 is arranged between the rotor 3 a of the electric motor 3 and the first speed drive gear 21.

One end of the second main input shaft 12 is connected to the output shaft 2a of the engine 2 via the second clutch C2, and the second main input shaft 12 and the output shaft 2a are connected in accordance with the connection/disconnection of the second clutch C2. Combined or blocked. That is, when the second clutch C2 is connected, the second main input shaft 12 and the output shaft 2a are coupled, and the torque from the engine 2 is input to the second main input shaft 12. On the other hand, when the second clutch C2 is disengaged, the second main input shaft 12 and the output shaft 2a are disengaged, and the torque input from the engine 2 is interrupted.

A gear 31 is fixed to the other end of the second main input shaft 12. The gear 31 meshes with an idle gear 32 fixed to the idle shaft 15, and the idle gear 32 meshes with a gear 33 fixed to the auxiliary input shaft 13. As a result, the torque of the second main input shaft 12 is transmitted to the sub input shaft 13 via the idle gear 32, and the sub input shaft 13 rotates together with the second main input shaft 12.

The second clutch C2 is a clutch for even gears, and the second input drive gear 22, the sixth drive gear 26, and the fourth drive gear 24 are arranged on the auxiliary input shaft 13 in this order from the electric motor 3 side. It is arranged. These drive gears 22, 24 and 26 are supported on the outer peripheral surface of the auxiliary input shaft 13 via bearings so as to be rotatable relative to the auxiliary input shaft 13.

A gear 34 is fixed to one end of the reverse shaft 16. The gear 34 meshes with the idle gear 32, whereby the torque of the second main input shaft 12 is input to the reverse shaft 16. A reverse drive gear 28 is supported on the outer peripheral surface of the reverse shaft 16 via bearings so as to be rotatable relative to the reverse shaft 16. The reverse drive gear 28 meshes with the reverse driven gear 35 fixed to the first main input shaft 11 between the fifth speed drive gear 25 and the gear 31.

The output shaft 14 has a 2-3 speed driven gear 41, a 6-7 speed driven gear 42, a 4-5 speed driven gear 43, a parking gear 44, and a final gear 45 in this order from the electric motor 3 side. Fixed to. The 2-3rd driven gear 41 meshes with the 2nd drive gear 22 and the 3rd drive gear 23, respectively. The 6-7th driven gear 42 meshes with the 6th drive gear 26 and the 7th drive gear 27, respectively. The 4th-5th driven gear 43 meshes with the 4th driving gear 24 and the 5th driving gear 25, respectively.

The parking gear 44 meshes with an engaging claw of a parking gear mechanism (not shown), and can lock and unlock the gear mechanism 10 according to the operation of the parking gear mechanism. The torque of the transmission 1 is transmitted to the left and right drive wheels 47 via the final gear 45 and the differential gear mechanism 46. The braking force is applied to the drive wheels 47 by the brake device 4. The brake device 4 is configured as, for example, a disc brake operated by hydraulic pressure.

The transmission 1 can rotate relative to the first main input shaft 11 and a first speed synchronizing mechanism SY1 that connects a first speed drive gear 21 that can rotate relative to the first main input shaft 11 to the first main input shaft 11. A third to seventh speed synchronizing mechanism SY2 that connects any one of the third speed driving gear 23 and the seventh speed driving gear 25 to the first main input shaft 11, and a fifth speed driving gear that is relatively rotatable with respect to the first main input shaft 11. A fifth speed synchronizing mechanism SY3 for connecting 25 to the first main input shaft 11 and one of the second speed drive gear 22 and the sixth speed drive gear 26, which are rotatable relative to the sub input shaft 13, are connected to the sub input shaft 13. 2-6 speed synchronizing mechanism SY4, 4th speed synchronizing mechanism SY5 which connects the 4th speed drive gear 24 which can rotate relative to the auxiliary input shaft 13 to the auxiliary input shaft 13, and reverse drive which allows relative rotation with respect to the reverse shaft 16. It has a reverse synchronization mechanism SY6 that connects the gear 28 to the reverse shaft 16.

The 1st speed synchronizing mechanism SY1, the 3-7th speed synchronizing mechanism SY2, the 5th speed synchronizing mechanism SY3, the 2-6th speed synchronizing mechanism SY4, the 4th speed synchronizing mechanism SY5 and the reverse synchronizing mechanism SY6 are collectively referred to as a synchronizing mechanism SY. There are cases. The synchronization mechanism SY is driven by hydraulic pressure, for example. This hydraulic pressure acts on the synchronizing mechanism SY according to the switching of a control valve (not shown).

2A and 2B are diagrams showing torque transmission paths when the first speed and the third speed are established, respectively. As shown in FIG. 2A, in the state where the first speed stage is established, the output shaft 2a of the engine 2 is coupled to the first main input shaft 11 via the first clutch C1, and the first speed synchronizing mechanism SY1 is used. The first speed drive gear 21 is coupled to the planetary gear mechanism 20. As a result, the torque of the engine 2 is transmitted to the output shaft 14 via the first clutch C1, the first main input shaft 11, the planetary gear mechanism 20, the first speed drive gear 21, the third speed drive gear 23, and the second and third speed driven gears 41. The vehicle 100 travels at the first speed.

As shown in FIG. 2B, in the state where the third speed is established, the output shaft 2a of the engine 2 is coupled to the first main input shaft 11 via the first clutch C1 and the 3-7 speed synchronizing mechanism SY2 is connected. The third speed drive gear 23 is connected to the first main input shaft 11 via the third speed drive gear 23. As a result, the torque of the engine 2 is transmitted to the output shaft 14 via the first clutch C1, the first main input shaft 11, the third speed drive gear 23, the third speed drive gear 23 and the 2-3rd driven gear 41, and the vehicle The 100 runs in 3rd speed. Although illustration is omitted, by switching between the clutch mechanism C and the synchronizing mechanism SY, it is possible to similarly switch to another gear. The gear ratio of the transmission 1 increases toward the low side, and the first gear is the largest. The larger the gear ratio, the larger the maximum traveling driving force.

In the present embodiment, the vehicle 100 is configured as an automatic driving vehicle having an automatic driving function. It should be noted that the vehicle 100 can be driven not only in an automatic driving mode in which a driver does not need to perform a driving operation, but also in a manual driving mode in which a driver operates.

FIG. 3 is a block diagram schematically showing a basic overall configuration of a vehicle control system 101 for controlling the autonomous driving vehicle 100. As shown in FIG. 2, the vehicle control system 101 includes a controller 60, an external sensor group 51 electrically connected to the controller 60, an internal sensor group 52, an input/output device 53, and a GPS receiver 54. , A map database 55, a navigation device 56, a communication unit 57, and a traveling actuator AC.

The external sensor group 51 is a general term for a plurality of sensors that detect an external situation that is peripheral information of the vehicle 100. For example, the external sensor group 51 may be a lidar that measures scattered light with respect to irradiation light in all directions of the vehicle 100 to measure a distance from the vehicle 100 to an obstacle in the vicinity, and a vehicle that emits electromagnetic waves and detects reflected waves. A radar that detects other vehicles and obstacles around 100, a camera that is mounted on the vehicle 100, and that has an image sensor such as a CCD or a CMOS and that captures images around the vehicle 100 (front, rear, and sides), and the like. included. The detection signal from the external sensor group 51 is input to the controller 60.

The internal sensor group 52 is a general term for a plurality of sensors that detect the traveling state of the vehicle 100. For example, the internal sensor group 52 includes a vehicle speed sensor that detects the vehicle speed of the vehicle 100, an acceleration sensor that detects the longitudinal acceleration and the lateral acceleration of the vehicle 100, an engine speed sensor that detects the rotational speed of the engine 2, A yaw rate sensor that detects the rotational angular velocity of the center of gravity of the vehicle 100 about the vertical axis, a throttle opening sensor that detects the opening of the throttle valve (throttle opening), and the like are included. The internal sensor group 52 also includes a sensor that detects a driver's driving operation in the manual driving mode, such as an accelerator pedal operation, a brake pedal operation, or a steering operation. The detection signal from the internal sensor group 52 is input to the controller 60.

The input/output device 53 is a general term for a device that receives commands from the occupant and outputs information to the occupant. For example, in the input/output device 53, various switches for the occupant to input various commands by operating the operation members, a microphone for the occupant to input commands by voice, a display unit for providing information to the occupant via a display image, and a voice for the occupant. It includes a speaker that provides information in. The various switches include a manual automatic changeover switch for instructing either an automatic operation mode or a manual operation mode.

The manual automatic changeover switch, for example, is configured as a switch that can be manually operated by the driver, and according to the switch operation, a changeover command to the automatic operation mode with the automatic operation function enabled or the manual operation mode with the automatic operation function invalidated is issued. Output. Even if the automatic driving switch is not operated, a command to switch from the manual operation mode to the automatic operation mode or from the automatic operation mode to the manual operation mode is issued when a predetermined traveling condition is satisfied. Good. That is, the mode switching may be performed automatically instead of manually by automatically switching the manual automatic changeover switch. The signal from the input/output device 53 is input to the controller 60. A signal is input to the input/output device 53 from the controller 60.

The GPS receiver (GPS sensor) 54 receives positioning signals from a plurality of GPS satellites, and thereby measures the absolute position (latitude, longitude, etc.) of the vehicle 100. The signal from the GPS receiver 54 is input to the controller 60.

The map database 55 is a device that stores general map information used in the navigation device 56, and is composed of, for example, a hard disk. The map information includes road position information, road shape (curvature, etc.) information, and intersection and branch point position information. The map information stored in the map database 55 is different from the highly accurate map information stored in the storage unit 62 of the controller 60.

The navigation device 56 is a device that searches for a target route on the road to the destination input by the driver and provides guidance along the target route. The input of the destination and the guidance along the target route are performed via the input/output device 53. The target route is calculated based on the current position of the vehicle measured by the GPS receiver 54 and the map information stored in the map database 55. The signal from the navigation device 56 is input to the controller 60.

The communication unit 57 communicates with various servers (not shown) via a network including a wireless communication network such as an internet line, and acquires map information and traffic information from the server periodically or at an arbitrary timing. The communication unit 57 outputs the acquired map information to the map database 55 and the storage unit 62 by communicating with the controller 60, thereby updating the map information. The acquired traffic information includes traffic congestion information and traffic light information such as the remaining time until the traffic light changes from red to blue.

The actuator AC is a traveling actuator for controlling traveling of the vehicle 100. The actuator AC includes various actuators that operate by an electric signal from the controller 60. For example, a throttle actuator that adjusts the opening degree of the throttle valve of the engine 2, a clutch actuator that drives the clutch C, a transmission actuator that drives the synchronous mechanism SY of the transmission 1, and a brake that operates the brake device 4. Actuator, and a steering actuator that drives the steering device. These actuators can be configured by an electric motor, a control valve that controls the flow of hydraulic pressure for driving the actuator, and the like.

The controller 60 is composed of an electronic control unit (ECU). Although a plurality of ECUs having different functions, such as an engine control ECU and a transmission control ECU, can be provided separately, in FIG. 3, the controller 60 is shown as a set of these ECUs for the sake of convenience. The controller 60 is configured to include a computer including a calculation unit 61 such as a CPU, a storage unit 62 such as a ROM, a RAM, a hard disk, and other peripheral circuits (not shown).

The storage unit 62 stores highly accurate detailed map information including information on the center position of the lane and information on the boundary of the lane position. More specifically, road information, traffic regulation information, address information, facility information, telephone number information, parking lot information, and the like are stored as map information. The road information includes information indicating the types of roads such as highways, toll roads, and national roads, the number of lanes on the road, the width of each lane, the slope of the road, the three-dimensional coordinate position of the road, the curvature of the lane curve, and the lane It includes information on the positions of confluence and branch points, road signs, etc. The traffic regulation information includes information that the lane is restricted from running or closed due to construction or the like. The storage unit 62 also stores information such as a shift map (shift diagram) that serves as a reference for gear shifting operation, programs for various controls, and threshold values used in the programs.

The calculation unit 61 has a vehicle position recognition unit 63, an outside world recognition unit 64, an action plan generation unit 65, and a travel control unit 66 as a functional configuration.

The vehicle position recognition unit 63 recognizes the position of the vehicle 100 (vehicle position) on the map based on the position information of the vehicle 100 received by the GPS receiver 54 and the map information of the map database 55. The own vehicle position may be recognized using the map information (information such as the shape of the building) stored in the storage unit 62 and the peripheral information of the vehicle 100 detected by the external sensor group 51. Can be recognized with high accuracy. When the position of the vehicle can be measured by a sensor installed on the road or outside the road, the position of the vehicle can be recognized with high accuracy by communicating with the sensor via the communication unit 57. it can.

The external environment recognition unit 64 recognizes an external situation around the vehicle 100 based on a signal from an external sensor group 51 such as a rider, a radar, and a camera. For example, the position, speed, and acceleration of peripheral vehicles (front vehicle and rear vehicle) traveling around the vehicle 100, the position of peripheral vehicles parked or parked around the vehicle 100, the position and state of other objects, and the like are displayed. recognize. Other objects include signs, traffic lights, road boundaries and stop lines, buildings, guardrails, power poles, signs, pedestrians, bicycles, and the like. The states of other objects include the color of a traffic light (red, blue, yellow), the moving speed and direction of a pedestrian or a bicycle, and the like.

The action plan generation unit 65, for example, based on the target route calculated by the navigation device 56, the vehicle position recognized by the vehicle position recognition unit 63, and the external situation recognized by the external world recognition unit 64, the present time. To the predetermined time ahead, the running trajectory (target trajectory) of the vehicle 100 is generated. When there are a plurality of candidate trajectories on the target route, the action plan generation unit 65 selects the optimum trajectory from among them that complies with the law and runs efficiently and safely. Then, the selected trajectory is set as the target trajectory. Then, the action plan generation unit 65 generates an action plan according to the generated target trajectory.

In the action plan, travel plan data set for each unit time (for example, 0.1 seconds) from the present time to a predetermined time (for example, 5 seconds) ahead, that is, set in association with the time for each unit time. Includes travel plan data. The travel plan data includes position data of the vehicle 100 and vehicle state data for each unit time. The position data is, for example, target point data indicating a two-dimensional coordinate position on the road, and the vehicle state data is vehicle speed data indicating the vehicle speed, direction data indicating the direction of the vehicle 100, and the like. The travel plan is updated every unit time.

The action plan generation unit 65 generates the target trajectory by connecting the position data for each unit time from the present time to a predetermined time (for example, 5 seconds) ahead in time order. At this time, the acceleration (target acceleration) for each unit time is calculated based on the vehicle speed (target vehicle speed) at each target point for each unit time on the target trajectory. That is, the action plan generation unit 65 calculates the target vehicle speed and the target acceleration. The target acceleration may be calculated by the traveling control unit 66. The driving force for achieving the target acceleration corresponds to the required driving force. Therefore, calculating the target acceleration is equivalent to calculating the required driving force.

The action plan generation unit 65 first determines the traveling mode when generating the target trajectory. Specifically, overtaking traveling for overtaking a vehicle in front, lane changing traveling for changing the traveling lane, lane keeping traveling for keeping the lane so as not to deviate from the traveling lane, deceleration traveling or acceleration traveling, parking traveling, etc. To decide. Then, the target trajectory is generated based on the traveling mode. The parking traveling includes admission traveling to enter (enter) the parking lot and exit traveling to leave (exit) from the parking lot. When the traveling mode is determined to be parking traveling, the behavior plan generating unit 65 travels such that the vehicle 100 enters the parking lot recognized by the vehicle control system 101 or the vehicle 100 exits from the parking lot. Generate planning data.

In the automatic driving mode, the traveling control unit 66 controls the actuator AC so that the vehicle 100 travels at the target vehicle speed and the target acceleration along the target trajectory generated by the action plan generating unit 65. That is, the throttle actuator, the clutch actuator, the transmission actuator, the brake actuator, and the steering actuator are controlled so that the vehicle 100 passes the target point for each unit time.

Particularly regarding the control of the transmission 1, the traveling control unit 66 determines a target shift speed according to the vehicle speed and the required driving force according to a predetermined shift map, and shifts the shift speed to the target shift speed. Control the actuator. Although illustration is omitted, the shift map is set to have a characteristic that the lower the vehicle speed, the lower the target shift speed becomes, and when the vehicle speed is equal to or lower than the predetermined value, the target shift speed becomes the first shift speed.

FIG. 4 is a plan view showing an example of a traveling operation of the vehicle 100 by the vehicle control system 101. FIG. 4 shows an example in which a vehicle 100 traveling on a road 110 parks sideways (in a direction orthogonal to the lane) in a parking lot 111 facing the road 110 by automatic driving. That is, for example, a parking lot 111 at a predetermined position is set as a destination of the autonomous driving vehicle 100, and an example of entry traveling in which the vehicle 100 enters the parking lot 111 by automatic driving is shown.

More specifically, the vehicle 100 once passes in front of the parking lot 111 as indicated by an arrow A1, and is parked based on the position information from the GPS receiver 54 and the image signal from the vehicle-mounted camera (external sensor group 51). When the position of the parking lot 111 is recognized, the parking mode is switched to the automatic parking mode, and entry traveling is started. In the automatic parking mode, as shown by an arrow A2, the vehicle travels backward to enter the parking lot 111. It should be noted that the vehicle 100 may be turned back, for example, by moving the vehicle 100 once in the forward direction and then in the backward direction. The vehicle 100 may be entered from the front side instead of entering the parking lot 111 from the rear side.

In the automatic parking mode, the traveling control unit 66 outputs a control signal to the actuator AC so that the vehicle 100 travels with the creep torque. More specifically, the traveling control unit 66 outputs a control signal to the throttle actuator to control the engine speed to a predetermined idle speed, and outputs a control signal to the clutch actuator to set the clutch C to the half-clutch. Then, the braking force by the brake device 4 is controlled so that the vehicle 100 travels at the target vehicle speed by outputting the control signal to the brake actuator.

By the way, the vehicle 100 travels at a low speed during parking traveling (at the time of admission traveling and at the time of exit traveling). At this time, if the shift stage of the transmission 1 is controlled to the first shift stage according to the shift map, the following problems occur. There is. FIG. 5 is a diagram showing the relationship between the engine speed Ne and the creep torque Tc. The characteristics f1 to f3 in the figure are characteristics at the first speed, the second speed, and the third speed, respectively. Generally, the creep torque Tc is proportional to the square of the engine speed Ne and the gear ratio of the transmission 1. Therefore, as shown in FIG. 5, the creep torque Tc increases as the engine speed Ne increases, and the creep torque Tc increases as the gear shifts toward the low side. Therefore, when the engine speed is the idle speed Nei, the creep torque at the first speed becomes maximum.

FIG. 6 is a diagram showing an example of changes over time of creep torque Tc, braking torque Tb, and vehicle speed V when creeping at the first speed. The difference ΔT between the creep torque Tc and the braking torque Tb becomes the actual driving torque. As shown in FIG. 6, at the first speed, the creep torque Tc is relatively large and the braking torque Tb is also large. Therefore, for example, when the rotation fluctuation of the engine 2 occurs at the time point t1, the fluctuation amount of the creep torque Tc is amplified, and the creep torque Tc significantly changes (for example, increases). As a result, the variable force of the vehicle speed V is large, and it becomes difficult to drive the vehicle at the target vehicle speed in the automatic parking mode, and the controllability of the vehicle 100 deteriorates. In consideration of this point, in the present embodiment, in order to improve the controllability of the vehicle 100 in the automatic parking mode, the vehicle control device is configured as follows.

FIG. 7 is a block diagram showing the main configuration of the vehicle control device 70 according to the present embodiment. The vehicle control device 70 is a device for moving the vehicle 100 to the parking lot 111 in the automatic transportation parking mode, and constitutes a part of the vehicle control system 101 of FIG. 3. As shown in FIG. 7, the vehicle control device 70 includes a controller 60, a GPS receiver 54 connected to the controller 60, a camera 51a, a vehicle speed sensor 52a, a throttle actuator 71, and a clutch actuator 72. It has a transmission actuator 73 and a brake actuator 74.

The camera 51a images the periphery of the vehicle 100, and the vehicle speed sensor 52a detects the vehicle speed. The camera 51a constitutes a part of the external sensor group 51 of FIG. 3, and the vehicle speed sensor 52a constitutes a part of the internal sensor group 52. The signals from the camera 51a and the vehicle speed sensor 52a are input to the controller 60 together with the signal from the GPS receiver 54. The throttle actuator 71, the clutch actuator 72, the transmission actuator 73, and the brake actuator 74 form a part of the actuator AC in FIG.

The controller 60 has a parking command unit 601, an engine control unit 602, a clutch control unit 603, a transmission control unit 604, and a brake control unit 605 as a functional configuration. The parking command unit 601 constitutes, for example, a part of the action plan generating unit 65 of FIG. 3, and the engine control unit 602, the clutch control unit 603, the transmission control unit 604, and the brake control unit 605, for example, travel in FIG. It constitutes a part of the control unit 66.

The parking command unit 601 commands the start of travel (start of entrance travel) in the automatic parking mode when the vehicle 100 is automatically parked at the target parking position, that is, when the vehicle 100 enters the parking lot 111. The command recognizes the target parking position by the vehicle 100 (the controller 60) based on the position information of the vehicle 100 measured by the GPS receiver 54 and the image signal of the camera 51a capturing the surroundings of the vehicle 100, for example. When it is output. Furthermore, the parking command unit 601 detects the parking state in which the vehicle 100 is parked in the parking lot 111 based on the signals from the GPS receiver 54 and the camera 51a, and when the vehicle 100 enters the parking state, Instruct to start running in the automatic parking mode (start running in the parking lot).

When the parking command unit 601 issues a command to start traveling in the automatic parking mode, the engine control unit 602 outputs a control signal to the throttle actuator 71 so that the engine speed Ne becomes a predetermined idle speed Nei. The engine control unit 602 outputs a control signal to the throttle actuator 71 in accordance with the required driving force when the start of traveling in the automatic parking mode is not instructed.

When the parking command unit 601 issues a command to start traveling in the automatic parking mode, the clutch control unit 603 connects the first clutch C1 in the half-clutch state and disconnects the second clutch C2, that is, from the engine 2. A control signal is output to the clutch actuator 72 so that a part of the torque of (1) is input to the transmission 1 and a creep torque can be generated. The clutch control unit 603 outputs a control signal to the clutch actuator 72 according to the required driving force to disconnect or connect the clutch C when the traveling start in the automatic parking mode is not instructed.

When the parking command unit 601 issues a command to start traveling in the automatic parking mode, the transmission control unit 604 drives the actuator 73 for the transmission so that the 3rd-7th speed synchronizing mechanism SY2 is driven to change the speed to the 3rd speed. Control signal is output to. The clutch control unit 603 sets the target shift speed according to the shift map according to the vehicle speed detected by the vehicle speed sensor 52a and the required driving force when the start of traveling in the automatic parking mode is not instructed, and this shift speed is the target shift speed. A control signal is output to the transmission actuator 73 so that the shift stage is reached.

When the parking command unit 601 issues a command to start traveling in the automatic parking mode, the brake control unit 605 brakes according to the vehicle speed detected by the vehicle speed sensor 52a so that the vehicle 100 travels at the target vehicle speed due to the creep torque. A control signal is output to the actuator 74 for. The brake control unit 605 outputs a control signal to the brake actuator 74 in accordance with the required driving force when the traveling start in the automatic parking mode is not instructed.

FIG. 8 is a flowchart showing an example of processing executed by the CPU of the controller 60 of FIG. 7 according to a program stored in advance. The process shown in this flowchart is started, for example, after the parking lot 111 (FIG. 4) is set as the destination of the automatic driving mode and the commands for the entry traveling and the departure traveling are enabled, and as long as the automatic driving mode continues. , Is repeated in a predetermined cycle.

First, in step S1, it is determined whether or not the automatic parking mode is commanded by the parking command unit 601. The automatic parking mode is commanded when the vehicle 100 enters the parking lot 111 by creep running and when the vehicle 100 exits from the parking lot 111 by creep running. Therefore, in step S1, whether or not the vehicle 100 (controller 60) recognizes the target parking position based on the position information of the vehicle 100 measured by the GPS receiver 54 and the image signal of the camera 51a (at the time of entry) ), and whether or not the vehicle 100 recognizes that the vehicle 100 is parked in the parking lot 111 (at the time of participation).

When the result in step S1 is affirmative, the process proceeds to step S2, in which a control signal is output to the throttle actuator 71 to control the engine speed Ne to a predetermined idle speed Nei. Next, in step S3, a control signal is output to the clutch actuator 72 to connect the first clutch C1 to the half clutch state and disconnect the second clutch C2. Next, in step S4, a control signal is output to the transmission actuator 73 to switch the shift speed to the third speed. The shift speed is switched to the third speed only during forward running, and the shift speed is switched to reverse during backward driving. Next, in step S5, a control signal is output to the brake actuator 74, and the braking force is adjusted so that the vehicle speed detected by the vehicle speed sensor 52a becomes the target vehicle speed.

On the other hand, when the result in step S1 is negative, that is, when the automatic parking mode is not commanded, the process proceeds to step S6, and normal control for the engine 2, the clutch C, the transmission 1, and the brake device 4 is executed. For example, a control signal is output to the throttle actuator 71 and the clutch actuator 72 according to the required driving force to control the operation of the engine 2 and the clutch C, and the transmission actuator according to the vehicle speed and the required driving force. A control signal is output to 73 to change the gear position.

FIG. 9 is a diagram showing an example of changes over time in the creep torque Tc, the braking torque Tb, and the vehicle speed V when the automatic parking mode is commanded by the vehicle control device 70 according to the present embodiment. In this embodiment, when the driving in the automatic parking mode is instructed, the transmission 1 is set to the third speed and the vehicle 100 creeps. Therefore, as shown in FIG. 9, the creep torque Tc and the braking torque Tb are smaller than when the first speed is set (FIG. 5). Therefore, for example, at time t2, when the rotation fluctuation of the engine 2 occurs, the change amount (for example, the increase amount) of the creep torque Tc is small and the vehicle speed fluctuation amount is small. Therefore, the vehicle 100 can be driven at a stable vehicle speed V along the target vehicle speed, and the controllability of the vehicle 100 in the automatic parking mode is improved.

According to this embodiment, the following operational effects can be achieved.
(1) The vehicle control device 70 controls the traveling operation of the vehicle 100 including the engine 2 and the transmission 1 that shifts the rotation caused by driving the engine 2 and transmits the rotation to the wheels (FIG. 1 ). The vehicle control device 70 includes a parking command unit 601 that commands traveling in a parking mode in which the vehicle 100 enters or leaves the parking lot, and a transmission control unit 604 that controls the gear ratio of the transmission 1. (FIG. 7). When the parking command unit 601 issues an instruction to drive the vehicle in the parking mode, the transmission control unit 604 reduces the maximum gear ratio of the transmission 1 during forward traveling as compared to when the vehicle travels in the parking mode is not instructed. That is, during normal traveling before the driving in the parking mode is instructed, the lowest shift speed is set to the first speed, and when the driving in the parking mode is instructed, the speed is switched to the third speed.

As a result, the creep torque during parking travel is reduced, and the amount of change in vehicle speed due to fluctuations in the rotation of the engine 2 is reduced. Therefore, the controllability of the vehicle 100 is improved and the vehicle 100 can be stably driven along the low target vehicle speed.

(2) The vehicle 100 is configured as an automatic driving vehicle having an automatic driving function (FIG. 3). The vehicle control device 70 further includes a GPS receiver 54 and a camera 51a that recognize the target parking position (parking lot 111) of the vehicle 100 (FIG. 7). When the target parking position is recognized based on the signals from the GPS receiver 54 and the camera 51a, the parking command unit 601 commands traveling in the parking mode (entry traveling). As a result, since the shift speed is switched to the third speed when the vehicle travels to the parking lot 111, it is possible to easily realize the traveling that requires the position adjustment of the vehicle 100.

(3) Further, the vehicle control device 70 detects the state in which the vehicle 100 is parked in the parking lot 111 based on the signals from the GPS receiver 54 and the camera 51a. Then, when the state where the vehicle 100 is parked in the parking lot is detected, the parking instruction unit 601 issues an instruction to travel in the parking mode (running out). As a result, when the vehicle is traveling from the parking lot 111, the shift speed is switched to the third speed, so that the vehicle 100 can easily enter the parking lot 111.

(4) The vehicle 100 further includes a brake device (braking device) 4 (FIG. 1). When the parking command unit 601 instructs the vehicle control device 70 to travel in the parking mode, the vehicle control device 70 controls the rotation speed Ne of the engine 2 to a predetermined idle rotation speed Nei so that the vehicle 100 travels at the creep torque. It further includes a unit 602 and a brake control unit (braking device control unit) 605 that controls the brake device 4 so that the vehicle 100 travels at the target vehicle speed (FIG. 7 ). As a result, the vehicle 100 can be satisfactorily automatically parked with the creep torque while controlling the vehicle speed to the target vehicle speed.

The above embodiment can be modified into various forms. Hereinafter, modified examples will be described. In the above embodiment, the clutch C is used to generate the creep torque. However, if the accuracy of the clutch C is deteriorated, the amount of fluctuation of the creep torque or the vehicle speed becomes large. In order to avoid this, the automatic parking traveling may be started after learning various characteristics of the clutch C (characteristics such as temperature and pressure of clutch hydraulic oil, stroke, clutch torque, etc.) in a stopped state. Alternatively, the clutch hydraulic pressure may be temporarily released to the atmosphere while the vehicle is stopped, and then a forced refill for returning the clutch hydraulic pressure to the original state may be executed, and the automatic parking traveling may be started after the forced refill. In the low temperature state, the idle speed Nei of the engine 2 may increase and the creep torque and the vehicle speed may significantly change. Therefore, the automatic parking traveling may be prohibited in the low temperature state and when the accuracy of the clutch C is deteriorated.

In the above embodiment, the target parking position of the vehicle 100 at the time of entering and traveling in the parking mode is recognized based on the signals from the GPS receiver 54 and the camera 51a. The target parking position may be recognized based on, and the configuration of the parking position recognition unit is not limited to this. In the above embodiment, the state in which the vehicle 100 is parked in the parking lot 111 is detected based on the signals from the GPS receiver 54 and the camera 51a when the vehicle runs in the parking mode. The configuration of the parking detection unit is not limited to this. That is, the configuration of the parking command unit may be any configuration as long as the vehicle is commanded to travel in the parking mode for entering or leaving the parking lot.

In the above embodiment, when the parking command unit 601 issues a command to travel in the parking mode, the transmission 1 is switched to the third speed in response to a command from the transmission control unit 604. It may be switched to the second speed or the fourth speed). That is, when the parking command unit issues a command to drive the vehicle in the parking mode, as long as the maximum gear ratio of the transmission is made smaller than when the vehicle is not commanded to drive the vehicle in the parking mode, the structure of the transmission control unit is It may be one. In the above-described embodiment, the stepped transmission is used as the transmission 1. However, a continuously variable transmission may be used. In this case, when traveling in the parking mode is instructed, traveling in the parking mode is not instructed. The maximum gear ratio of the continuously variable transmission may be made smaller than that.

In the above embodiment, the clutch C is in the half-clutch state to generate the creep torque, but a torque converter may be used instead of the clutch C to generate the creep torque. In the above-described embodiment, the vehicle 100 is configured as a hybrid vehicle having the engine 2 and the electric motor 3 as a traveling drive source, but may be other than the hybrid vehicle as long as it has at least the engine and the transmission.

In the above-described embodiment, the vehicle control device 70 is applied to the autonomous driving vehicle 100, but the vehicle control device of the present invention is also applicable to a vehicle having only some automatic driving functions, such as a vehicle having a parking assist device. Can be applied to. It can also be applied to a vehicle that is manually parked.

The above description is merely an example, and the present invention is not limited to the above-described embodiments and modifications unless the characteristics of the present invention are impaired. It is also possible to arbitrarily combine one or more of the above-described embodiment and modified examples, and it is also possible to combine modified examples.

1 transmission, 2 engine, 4 braking device, 51a camera, 54 GPS receiver, 60 controller, 73 transmission actuator, 100 vehicle, 601 parking command section, 602 engine control section, 604 transmission control section, 605 brake control Department

Claims (4)

A vehicle control device for controlling a traveling operation of a vehicle, comprising: an engine;
A parking command unit for instructing traveling in a parking mode in which the vehicle enters or leaves the parking lot,
A transmission control unit for controlling a transmission ratio of the transmission,
The transmission control unit is configured to reduce the maximum gear ratio of the transmission when the parking command unit instructs the vehicle to travel in the parking mode as compared to when the parking mode is not commanded. Vehicle control device. The vehicle control device according to claim 1,
The vehicle is an autonomous vehicle having an autonomous driving function,
Further comprising a parking position recognition unit for recognizing a target parking position of the vehicle,
The vehicle control device, wherein the parking command unit commands travel in a parking mode when the target parking position is recognized by the parking position recognition unit. The vehicle control device according to claim 1,
The vehicle is an autonomous vehicle having an autonomous driving function,
Further comprising a parking detection unit for detecting a state in which the vehicle is parked in a parking lot,
The vehicle control device, wherein the parking command unit commands the vehicle to travel in a parking mode when the parking detection unit detects that the vehicle is parked in a parking lot. The vehicle control device according to claim 2 or 3,
The vehicle further includes a braking device,
When the parking command unit instructs the vehicle to travel in the parking mode, the engine control unit controls the engine speed to a predetermined idle speed so that the vehicle travels at a creep torque, and the vehicle has a target vehicle speed. A vehicle control device further comprising: a braking device control unit that controls the braking device so that the vehicle travels in the vehicle.

Images