Vehicular control apparatus

Abstract

To provide a vehicular control apparatus capable of optimally performing lockup clutch connect / disconnect control during an automatic operation travel.SOLUTION: An electronic control apparatus 80 includes: an automatic operation control part 88 for controlling an automatic operation travel; a reaching prediction period calculation part 94 for calculating an inter-vehicle distance reaching prediction period Td or a vehicle speed reaching prediction period Tv that is required to reach a target inter-vehicle distance Dt or a target vehicle speed Vt with an inter-vehicle distance D with a preceding vehicle or a vehicle speed V in a case where the vehicle is in an automatic operation travel with an LU clutch 36 engaged; and a first disengage-engage control part 92 for disengaging the LU clutch 36 in a case where the inter-vehicle distance reaching prediction period Td or vehicle speed reaching prediction period Tv is larger than a preset target reaching period Tg, and continuing the LU clutch 36 engaged in a case where the inter-vehicle distance reaching prediction period Td or vehicle speed reaching prediction period Tv is equal or smaller than the target reaching period Tg.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle equipped with a torque converter with a lock-up clutch and an automatic driving function. [Background technology]

[0002] In a vehicle equipped with a torque converter with a lock-up clutch and an automatic driving function, a technology has been disclosed for suppressing vehicle speed fluctuations when the lock-up clutch is engaged and the vehicle is running automatically. For example, Patent Document 1 discloses a vehicle control device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-214247 Summary of the Invention [Problem to be solved by the invention]

[0004] In the autonomous driving of a vehicle, not only is vehicle speed fluctuation suppressed, but driving force control according to the driving route is also performed. For example, the road inclination angle is obtained from map data, and if the road to be driven is an uphill road, control is performed to increase driving force in advance according to the inclination angle. In such a case, if the lockup clutch is engaged and driving force is insufficient, it is necessary to switch the lockup clutch to a disengaged state and increase the driving force by amplifying the torque of the torque converter. However, because conventional lockup clutch engagement / disengagement control is performed based on the current accelerator pedal position and vehicle speed, the lockup clutch is not immediately switched to a disengaged state, resulting in a delay in increasing driving force. In other words, the lockup clutch engagement / disengagement control is not optimal for autonomous driving, and there is room for improvement in lockup clutch engagement / disengagement control during autonomous driving.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to provide a vehicle control device that optimally controls the engagement and disengagement of a lock-up clutch during autonomous driving. [Means for solving the problem]

[0006] The gist of the present invention is that it includes (a) a control device for a vehicle equipped with a torque converter with a lock-up clutch, and (b) an automatic driving control unit that controls automatic driving, and when the lock-up clutch is engaged during the automatic driving, a predicted arrival period calculation unit that calculates a predicted arrival period for the vehicle distance or vehicle speed to reach a target vehicle distance or target vehicle speed from a preceding vehicle, and a first engagement / disengagement control unit that switches the lock-up clutch to a released state if the predicted arrival period is greater than a predetermined target arrival period, and controls the lock-up clutch to continue to be engaged if the predicted arrival period is equal to or less than the target arrival period. [Effects of the Invention]

[0007] The vehicle control device of the present invention includes an autonomous driving control unit that controls autonomous driving; an arrival prediction period calculation unit that calculates, when the vehicle is traveling autonomously and the lockup clutch is engaged, an arrival prediction period required for the vehicle distance or vehicle speed to reach a target vehicle distance or target vehicle speed from a preceding vehicle; and a first engagement / disengagement control unit that controls the lockup clutch to be disengaged if the arrival prediction period is greater than a predetermined target arrival period, and to maintain the lockup clutch engaged if the arrival prediction period is equal to or less than the target arrival period. As a result, if it is predicted that the target vehicle distance or target vehicle speed will not be reached within the target arrival period, the lockup clutch is disengaged, thereby increasing driving force through the torque amplification effect of the torque converter and shortening the arrival period. Therefore, the engagement / disengagement control of the lockup clutch is optimally performed during autonomous driving. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating control functions and main parts of a control system for various controls in the vehicle. [Figure 2] 10 is an example of a lockup switching map that is predetermined as a lockup clutch engagement / disengagement condition. [Figure 3] 2 is an example of a flowchart illustrating a control operation of the electronic control device shown in FIG. 1 for controlling connection and disconnection of a lock-up clutch during autonomous driving. [Figure 4] 4 is an example of a flowchart illustrating a control operation of the electronic control device shown in FIG. 1 for controlling connection and disconnection of the lock-up clutch when the driving mode is changed during automatic driving. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. [Example]

[0010] Fig. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and also illustrating the main parts of control functions for various controls in the vehicle 10. In Fig. 1, the vehicle 10 includes an engine 12 as a power source, wheels 14, and a power transmission device 16 provided in a power transmission path between the engine 12 and the wheels 14. The power transmission device 16 includes a torque converter 20, an automatic transmission 22, and the like, housed within a case 18. The power transmission device 16 also includes a propeller shaft 26 connected to a transmission output shaft 24, which is an output rotating member of the automatic transmission 22, a differential 28 connected to the propeller shaft 26, left and right drive shafts 30 connected to the differential 28, and the like.

[0011] The output torque of the engine 12 is controlled by an engine control device 40 provided in the vehicle 10 being controlled by an electronic control device 80, which will be described later.

[0012] The torque converter 20 is disposed in a power transmission path between the engine 12 and the automatic transmission 22, and is connected to the engine 12 via a crankshaft 32. The torque converter 20 includes a pump wheel 20p, a turbine wheel 20t, etc., and further includes a lock-up clutch (hereinafter referred to as an LU clutch) 36 that connects the pump wheel 20p and the turbine wheel 20t.

[0013] The automatic transmission 22 is connected to the engine 12 via the torque converter 20 and the input shaft 34. The automatic transmission 22 is a known planetary gear type stepped transmission that can select from a plurality of gear stages POSsh and that includes, for example, a plurality of sets of planetary gear devices and a plurality of hydraulic engagement devices CB such as clutches and brakes.

[0014] The vehicle 10 further includes a brake control device 42 and a steering control device 46. The brake control device 42 controls the braking force of brakes 44 for braking the wheels 14, which are provided on the wheels 14. The steering control device 46 controls the steering angle of the wheels 14.

[0015] The vehicle 10 is equipped with an electronic control device 80 as a controller of the vehicle 10. The electronic control device 80 is supplied with various signals (e.g., engine rotation speed Ne (rpm), AT output rotation speed No (rpm) corresponding to vehicle speed V (Km / h), accelerator pedal opening pap (%), steering angle Φ, brake pedal braking operation amount Bra, etc.) based on detection values ​​from an engine rotation speed sensor 60, an output rotation speed sensor 62, an accelerator pedal opening sensor 64, a steering angle sensor 66, a brake operation amount sensor 68, etc., which are equipped on the vehicle 10. The accelerator pedal opening pap corresponds to the accelerator operation of the driver of the vehicle 10.

[0016] The automatic driving setting switch 70 is a switch for setting automatic driving. Automatic driving includes fully automatic driving, in which the driving force and steering angle θ of the vehicle 10 are automatically controlled, and cruising driving, in which the vehicle travels at a constant speed or follows another vehicle without the driver's acceleration or deceleration. Either fully automatic driving or cruising driving is set by the driver's operation. The navigation system 72 is a device that has map information and displays or sets a driving route according to the destination, and acquires various road traffic information such as the vehicle's position, congestion, road, gradient, altitude, legal speed, and weather using GPS, VICS (registered trademark) (Vehicle Information and Communication System), etc. The radar 74 is a device that detects the distance between the vehicle and preceding vehicles, nearby pedestrians, or obstacles. The camera 76 is a device that captures images of the front, rear, and sides of the vehicle. The driving mode setting switch 78 is a switch for setting the driving mode of the vehicle 10. The driving modes include a sport mode or power mode that increases the driving force while driving, and an eco mode that decreases the driving force while driving, and are set by the driver. Signals representing the respective information about the above devices and switches are also sent to the electronic control unit 80.

[0017] The electronic control device 80 outputs various command signals (for example, an engine control command signal Se for controlling the engine 12, a brake control command signal Sb for controlling the braking force of the brake 44, a steering angle command signal Sr for controlling the steering angle of the wheels 14, a hydraulic control command signal Sat for controlling the operating state of the engagement device CB, a hydraulic control command signal Slu for controlling the operating state of the LU clutch 36, etc.) to the engine control device 40, the brake control device 42, the steering control device 46, the hydraulic control circuit 50, etc., which are provided in the vehicle 10.

[0018] The electronic control device 80 functionally comprises a drive control unit 82, a steering control unit 84, a brake control unit 86, an automatic driving control unit 88, and an LU clutch control unit 90. The LU clutch control unit 90 functionally comprises a first connection / disconnection control unit 92 and a second connection / disconnection control unit 96. The first connection / disconnection control unit 92 functionally comprises a predicted arrival period calculation unit 94.

[0019] The drive control unit 82 controls the engine 12. The drive control unit 82 calculates the required drive force F by applying the accelerator opening pap and the vehicle speed V to a predetermined drive force map. The drive control unit 82 outputs an engine control command signal Se to the engine control device 40 to realize the required drive force F. Furthermore, when automatic driving is set, the drive control unit 82 outputs the engine control command signal Se to the engine control device 40 so as to achieve a target required drive force Ft supplied from an automatic driving control unit 88, which will be described later.

[0020] The drive control unit 82 executes shift control of the automatic transmission 22. For example, the drive control unit 82 determines the gear position POSsh of the automatic transmission 22 using, for example, a shift map, which is a predetermined relationship. The drive control unit 82 outputs a hydraulic control command signal Sat to the hydraulic control circuit 50 to switch the operating state of the engagement device CB so as to achieve the determined gear position POSsh.

[0021] The steering control unit 84 controls the steering angle θ of the wheels 14. It outputs a steering angle command signal Sr to the steering control device 46 so that the wheels 14 are at a steering angle θ corresponding to the steering angle Φ supplied from the steering angle sensor 66. Furthermore, when full automatic driving is selected in the automatic driving mode, the steering control unit 84 outputs a steering angle command signal Sr to the steering control device 46 so that the wheels 14 are at a target steering angle θt supplied from an automatic driving control unit 88, which will be described later.

[0022] The brake control unit 86 controls the braking force β of the wheel brakes 44 provided on each wheel 14. The brake control unit 86 outputs a brake control command signal Sb to the brake control device 42 so that the braking force β corresponds to the brake operation amount Bra supplied from the brake operation amount sensor 68. Furthermore, when automatic driving is set, the brake control unit 86 outputs a brake control command signal Sb to the brake control device 42 so that the braking force β corresponds to a target braking force βt supplied from an automatic driving control unit 88, which will be described later.

[0023] When automatic driving is set, the automatic driving control unit 88 controls either fully automatic driving or cruising, depending on the setting. When fully automatic driving is set, the automatic driving control unit 88 creates a driving plan for the vehicle 10 along the target route set by the driver, based on, for example, vehicle position information, map information, and driving route information from the navigation system 72, and information such as the distance between the preceding vehicle and the following vehicle from the radar 74, etc.

[0024] The automatic driving control unit 88 sequentially sets a target vehicle speed Vt and a target inter-vehicle distance Dt from the preceding vehicle based on the aforementioned driving plan for the vehicle 10 and the aforementioned map information, etc., and further calculates a target required driving force Ft and a target braking force βt for achieving the target vehicle speed Vt and the target inter-vehicle distance Dt. Furthermore, when cruising is set, the target vehicle speed Vt and the target inter-vehicle distance Dt are set by the driver, and the automatic driving control unit 88 calculates the target required driving force Ft and the target braking force βt based on the set target vehicle speed Vt and target inter-vehicle distance Dt. Furthermore, the automatic driving control unit 88 supplies the target required driving force Ft to the drive control unit 82 and the arrival prediction period calculation unit 94, and supplies the target braking force βt to the brake control unit 86.

[0025] Furthermore, when fully autonomous driving is set, the autonomous driving control unit 88 supplies a target steering angle θt to the steering control unit 84. The target steering angle θt is determined based on information from the navigation system 72 and the camera 76 described above, and is set appropriately according to the vehicle speed V, the required driving force F, and the like, for example, to travel along a predetermined travel route, travel along a lane detected by the camera 76, or switch lanes.

[0026] The LU clutch control unit 90 outputs a hydraulic control command signal Slu to the hydraulic control circuit 50 so that the LU clutch 36 is brought into a disengaged state (released state or engaged state) by applying the vehicle driving state represented by the vehicle speed V and accelerator pedal position pap to a predetermined lockup operation region map. FIG. 2 shows an example of a lockup switching map that is predetermined as a condition for engaging or disengaging the LU clutch 36. In FIG. 2, the engagement and disengagement state of the LU clutch 36 is set based on the vehicle state of the vehicle 10 represented on a two-dimensional coordinate system of the vehicle speed V and accelerator pedal position pap. Note that in the lockup switching map, the AT output rotation speed No or the like may be used instead of the vehicle speed V, and the required driving force F or the like may be used instead of the accelerator pedal position pap.

[0027] The lockup switching map has predetermined "engagement → release" switching lines (switching of the LU clutch 36 from an engaged state to a released state) and "release → engagement" switching lines (switching of the LU clutch 36 from a released state to an engaged state). For example, when the point represented by the vehicle speed V and accelerator opening pap in Fig. 2 crosses the "engagement → release" switching line or the "release → engagement" switching line, it is determined that release control or engagement control of the LU clutch 36 is to be started.

[0028] In addition, during autonomous driving, the LU clutch control unit 90 performs engagement and disengagement control of the lock-up clutch, which will be described later, using a first engagement / disengagement control unit 92 (including a predicted arrival period calculation unit 94) and a second engagement / disengagement control unit 96, which are functionally provided in the LU clutch control unit 90.

[0029] 3 is an example of a flowchart illustrating the control operation of the first connection / disconnection control unit 92 (including the arrival prediction period calculation unit 94) that is functionally provided in the electronic control unit 80. The flowchart in FIG. 3 is repeatedly executed during autonomous driving. Hereinafter, the control operation will be described along the processing steps in FIG. 3.

[0030] First, in step S10 (hereinafter, the term "step" will be omitted) corresponding to the function of the first connection / disconnection control unit 92, it is determined whether the LU clutch 36 is in a released state. If the determination in S10 is positive, this routine is terminated.

[0031] If the determination in S10 is negative, an inter-vehicle distance arrival prediction period Td or a vehicle speed arrival prediction period Tv is calculated in S20, which corresponds to the function of the arrival prediction period calculation unit 94. The inter-vehicle distance arrival prediction period Td is the period required for the current inter-vehicle distance D to reach the target inter-vehicle distance Dt. The inter-vehicle distance arrival prediction period Td is the period required for the current vehicle speed V to reach the target vehicle speed Vt. The inter-vehicle distance arrival prediction period Td and the vehicle speed arrival prediction period Tv correspond to the "arrival prediction period" of the present invention.

[0032] The inter-vehicle distance arrival predicted period Td and the vehicle speed arrival predicted period Tv are calculated, for example, as follows: First, the predicted acceleration Ap is calculated based on the deviation ΔFt from the current driving force to the target required driving force Ft, information about the road along which the vehicle is about to travel (gradient, road surface condition), and information about the vehicle 10 (weight, running resistance, etc.). The vehicle speed arrival predicted period Tv is then given as a solution to the following equation (1) with time t as a variable, and is calculated using the following equation (2). Ap×t=|V-Vt| (1) Vehicle speed arrival prediction period Tv = (|V - Vt|) / Ap (2) Further, the inter-vehicle distance arrival prediction period Td is given as a solution of the following equation (3) in which time t is a variable, and is calculated by the following equation (4). ∫Ap×t 2 dt = |D-Dt| (3) Inter-vehicle distance reaching prediction period Td = ((3 × |D-Dt|) / Ap) 1 / 3 ···(4) Furthermore, the inter-vehicle distance arrival predicted period Td and the vehicle speed arrival predicted period Tv may be calculated by any other suitable method other than the above-mentioned formula, such as applying the predicted acceleration Ap and values ​​of |V-Vt|, |D-Dt|, etc. to a prepared map. Furthermore, the predicted acceleration Ap may be calculated as a time function Ap=Ap(t), and the inter-vehicle distance arrival predicted period Td and the vehicle speed arrival predicted period Tv may be calculated by any suitable method for finding the time t.

[0033] Next, in S30, which corresponds to the function of the first disconnection control unit 92, it is determined whether the inter-vehicle distance arrival prediction period Td or the vehicle speed arrival prediction period Tv calculated in S20 is equal to or shorter than the target arrival period Tg, i.e., whether the target inter-vehicle distance Dt or the target vehicle speed Vt can be reached within the target arrival period Tg. The target arrival period Tg is a value that is set in advance by design or experiment. Furthermore, the target arrival time Tg may be set to a suitable value separately for the inter-vehicle distance arrival prediction period Td and the vehicle speed arrival prediction period Tv. Note that the determination in S30 may be affirmative if either the inter-vehicle distance arrival prediction period Td or the vehicle speed arrival prediction period Tv is equal to or shorter than the target arrival period Tg, or may be affirmative if either one of the predetermined periods is equal to or shorter than the target arrival period Tg.

[0034] If the determination in S30 is negative, the LU clutch 36 is switched to the released state in S40, which corresponds to the function of the first connection / disconnection control unit 92. If the determination in S30 is positive, the LU clutch 36 continues to be engaged in S50, which corresponds to the function of the first connection / disconnection control unit 92. After execution of S40 and S50, this routine is ended.

[0035] If the control operation of the first engagement / disengagement control unit 92 predicts that the target inter-vehicle distance Dt or the target vehicle speed Vt will not be reached within the target arrival time Tg, the LU clutch 36 is switched to a released state, and the driving force is increased by the torque amplification action of the torque converter 20, thereby shortening the arrival time. Therefore, the engagement / disengagement control of the LU clutch 36 is optimally performed during autonomous driving.

[0036] Fig. 4 is an example of a flowchart illustrating the control operation of the second connection / disconnection control unit 96, which is functionally provided in the electronic control device 80. The flowchart in Fig. 4 is repeatedly executed during autonomous driving. Hereinafter, the control operation will be described along the processing steps in Fig. 4.

[0037] First, in step S100 (hereinafter, the term "step" will be omitted) corresponding to the function of the second connection / disconnection control unit 96, it is determined whether the LU clutch 36 is in a released state. If the determination in S100 is positive, this routine is terminated.

[0038] If the determination in S100 is positive, in S200, which corresponds to the function of the second connection / disconnection control unit 96, it is determined whether the driver has changed the driving mode to an eco mode that reduces the driving force during driving.

[0039] If the determination in S200 is positive, the LU clutch 36 is switched to the engaged state in S300, which corresponds to the function of the second connection / disconnection control unit 96. If the determination in S200 is negative, the LU clutch 36 continues to be released in S400, which corresponds to the function of the second connection / disconnection control unit 96. After execution of S300 and S400, this routine is ended.

[0040] When the driving mode is changed to an eco mode that reduces driving force during driving by the control operation of the second connection / disconnection control unit 96, the LU clutch 36 is switched to an engaged state. As a result, when the driving mode is changed by driver operation, the LU clutch 36 is controlled to be connected and disconnected with priority given to the driver operation, thereby reducing the sense of discomfort felt by the driver.

[0041] The electronic control device 80 of this embodiment includes an automatic driving control unit 88 that controls automatic driving; an arrival prediction period calculation unit 94 that, when the vehicle is traveling automatically and the LU clutch 36 is engaged, calculates an inter-vehicle distance arrival prediction period Td or a vehicle speed arrival prediction period Tv that it takes for the inter-vehicle distance D or the vehicle speed V to reach the target inter-vehicle distance Dt or the target vehicle speed Vt, respectively; and a first engagement / disengagement control unit 92 that switches the LU clutch 36 to a disengaged state if the inter-vehicle distance arrival prediction period Td or the vehicle speed arrival prediction period Tv is greater than a predetermined target arrival period Tg, and controls the LU clutch 36 to remain engaged if the inter-vehicle distance arrival prediction period Td or the vehicle speed arrival prediction period Tv is equal to or less than the target arrival period Tg. As a result, when it is predicted that the target inter-vehicle distance Dt or the target vehicle speed Vt will not be reached within the target arrival period Tg, the LU clutch 36 is switched to a disengaged state, thereby increasing the driving force through the torque amplification effect of the torque converter 20 and shortening the arrival period. Therefore, the engagement / disengagement control of the LU clutch 36 is optimally performed during automatic driving.

[0042] The electronic control device 80 of this embodiment further includes a second connection / disconnection control unit 96 that switches the LU clutch 36 to an engaged state when the driving mode is changed to an eco-driving mode that reduces driving force during automatic driving and when the driving mode is changed to a sport mode or power mode that increases driving force, and that controls the LU clutch 36 to continue to be in a released state. As a result, when the driving mode is changed by driver operation, the LU clutch 36 is controlled to be connected / disconnected, giving priority to the driver operation, thereby reducing the sense of discomfort felt by the driver.

[0043] The above-described embodiments of the present invention are merely examples, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention. [Explanation of symbols]

[0044] 10: Vehicle 20: Torque converter 36: LU clutch (lock-up clutch) 80: Electronic control unit (control unit) 88: Automatic driving control unit 92: First connection / disconnection control unit 94: Arrival prediction period calculation unit 96: Second connection / disconnection control unit D: Inter-vehicle distance Dt: Target inter-vehicle distance V: Vehicle speed Vt: Target vehicle speed Td: Inter-vehicle distance arrival prediction period (arrival prediction period) Tg: Target arrival period Tv: Vehicle speed arrival prediction period (arrival prediction period)

Claims

1. A control device for a vehicle equipped with a torque converter with a lock-up clutch, an autonomous driving control unit that controls autonomous driving; an arrival prediction period calculation unit that calculates an arrival prediction period required for the inter-vehicle distance or vehicle speed to reach a target inter-vehicle distance or target vehicle speed when the vehicle is traveling automatically and the lock-up clutch is engaged; a first engagement / disengagement control unit that switches the lock-up clutch to a released state when the predicted arrival period is greater than a predetermined target arrival period, and that controls the lock-up clutch to continue to be engaged when the predicted arrival period is equal to or less than the target arrival period. A vehicle control device characterized by:

2. When the vehicle is traveling automatically and the lock-up clutch is in a released state, The vehicle further includes a second engagement / disengagement control unit that switches the lockup clutch to an engaged state when the driving mode is changed to a setting that reduces the driving force, and that controls the lockup clutch to continue to be released when the driving mode is changed to a setting that increases the driving force.

2. The vehicle control device according to claim 1.

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