Vehicle control device

Abstract

To provide a control device of a vehicle capable of realizing a comfortable traveling feeling in a shift operation of an automatic transmission during execution of an ACC function.SOLUTION: The vehicle control device includes an automatic transmission 20 having a plurality of gear stages, and a transmission controller 40 configured to control the automatic transmission 20 so as to change the gear stage according to a vehicle speed V of a vehicle 1 and an accelerator opening or a throttle opening. When the ACC controller 41 determines to decelerate and stop the vehicle 1 during execution of the ACC function, the transmission controller 40 executes shift correction control of changing the gear stage of the automatic transmission 20 to a lower-speed gear stage in a stepwise manner, skipping the lowest-speed gear stage including at least the first speed stage, and changing the automatic transmission 20 to the neutral state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device configured to perform a gear shifting operation of an automatic transmission having a plurality of gear stages. [Background technology]

[0002] An automated manual transmission (AMT) is a type of automatic transmission with multiple gears that enables automatic shifting by adding an actuator that automatically performs gear shifting to a manual transmission. Automatic transmissions, including AMTs, are generally configured to change gears in stages according to a preset shift map. However, frequent downshifts during gear shifting can cause shift shocks that can be unpleasant for vehicle occupants. Patent Document 1, for example, discloses an automatic transmission with a multi-speed mechanism that performs 3-1 gear shifts in a low throttle opening range, thereby preventing frequent 3-2-1 gear shifts during deceleration and improving the driving feel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4692195 Summary of the Invention [Problem to be solved by the invention]

[0004] To assist the driver in driving, an adaptive cruise control (ACC) function is known that controls the vehicle's distance to maintain an appropriate distance from the preceding vehicle. For example, an all-speed range ACC function is configured to apply braking control to decelerate and stop the vehicle when the preceding vehicle decelerates and stops while the vehicle is being followed. When the vehicle decelerates and stops, the automatic transmission shifts to a lower gear according to the shift map described above. However, the lower the gear, the greater the deceleration caused by engine braking. Therefore, if the driver downshifts at an unintended timing, significant deceleration due to engine braking or shock (vibration) may occur, which may cause discomfort to the driver. In particular, when the ACC function is operating, the driver does not operate the pedals to accelerate or decelerate, making it difficult to predict the timing of gear changes. Therefore, if significant deceleration occurs due to the automatic transmission downshift, the driver may experience an unexpected change in vehicle behavior, resulting in a poor driving experience.

[0005] The present invention has been made in consideration of the above-described circumstances, and its purpose is to provide a vehicle control device that can achieve a comfortable driving feeling when shifting gears in an automatic transmission while the ACC function is running. [Means for solving the problem]

[0006] According to one aspect of the present invention, a vehicle control device includes an automatic transmission having multiple gear stages, a transmission controller configured to control the automatic transmission to change gear stages depending on the vehicle speed and accelerator or throttle opening, and an ACC controller configured to execute an ACC function that performs constant speed driving according to a set vehicle speed when there is no preceding vehicle in the lane in which the vehicle is traveling, and follows the preceding vehicle when there is a preceding vehicle.When the ACC controller determines to decelerate and stop the vehicle while the ACC function is being executed, the transmission controller executes gear shift correction control that gradually changes the gear stages of the automatic transmission to lower gear stages, skips the lowest gear stage including at least first gear stage, and changes the automatic transmission to a neutral state. [Effects of the Invention]

[0007] The vehicle control device according to the present invention can perform a gear shift operation of an automatic transmission that can achieve a comfortable driving feeling while the ACC function is being executed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a vehicle equipped with a vehicle control device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a schematic diagram of a change in gear position over time when the vehicle decelerates and stops while the ACC is not in operation. [Figure 3] FIG. 3 is a diagram showing an example of a change in gear position over time according to the first method when the vehicle decelerates and stops during ACC operation. [Figure 4] FIG. 4 is a diagram schematically showing an example of a change in gear position over time according to the second method when the vehicle decelerates and stops during ACC operation. [Figure 5] FIG. 5 is a flowchart illustrating the flow of the shift correction control when the vehicle decelerates and stops while the ACC is operating. DETAILED DESCRIPTION OF THE INVENTION

[0009] -First embodiment- A vehicle control system according to a first embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a block diagram showing a schematic configuration of a vehicle 1 and a vehicle control device according to this embodiment.

[0010] 1, the vehicle 1 includes an engine 10, an automatic transmission 20, a braking device 30, etc. The vehicle 1 further includes a transmission (TM) controller 40, an ACC controller 41, an engine controller 42, a brake controller 43, a surroundings detection device 50, an HMI device 51, etc.

[0011] The engine 10 is a drive device that generates driving force for the vehicle 1, and is configured by, for example, a gasoline engine. The operation of the engine 10 is controlled by an engine controller 42 in accordance with the amount of depression of an accelerator pedal (not shown) by the driver or in accordance with a control command from an ACC controller 41.

[0012] The automatic transmission 20 is a transmission with multiple gear stages, and includes a transmission mechanism 21, a clutch 22, and an actuator 23. The transmission mechanism 21 is a transmission mechanism commonly used in manual transmissions, such as a parallel gear transmission mechanism with a constant mesh synchromesh mechanism. The automatic transmission 20 has the structure of a manual transmission, and is configured as an AMT (Automated Manual Transmission) type transmission in which gear shifting operations are automated.

[0013] The clutch 22 is configured as, for example, a dry single-plate clutch, and includes a clutch disc connected to the input shaft of the transmission mechanism 21, a clutch spring that biases the clutch disc via a pressure plate, and a flywheel connected to the crankshaft of the engine 10. When the clutch disc is pressed against the flywheel by the biasing force of the clutch spring, the clutch 22 enters an engaged (connected) state and transmits the power of the engine 10 to the transmission mechanism 21. When the clutch disc moves away from the flywheel against the biasing force of the clutch spring and enters a disengaged state, the clutch 22 disconnects (blocks) the transmission of power from the engine 10 to the transmission mechanism 21.

[0014] Actuator 23 includes a shift actuator that switches the gear position of transmission mechanism 21, and a clutch actuator that engages and disengages clutch 22. The shift actuator and clutch actuator are each configured as, for example, a hydraulic actuator. An electric pump, hydraulic circuit, accumulator, electromagnetic valve, and the like that supply hydraulic pressure to the shift actuator and clutch actuator, respectively, are assembled into a unit and mounted on automatic transmission 20.

[0015] The actuator 23 is electrically connected to the TM controller 40, and performs a gear change operation consisting of clutch release, gear change, and clutch engagement by interlocking the gear change actuator and clutch actuator in response to a control signal from the TM controller 40. In this way, the automatic transmission 20 is configured to change the rotation of the engine 10 at a gear ratio according to the gear in response to a control signal from the TM controller 40, and transmit the rotation to the drive wheels 2 via a differential and drive shaft 3 (not shown).

[0016] The braking device 30 is a braking device that generates a braking force for the vehicle 1. The braking device 30 includes brakes (for example, disc brakes, drum brakes, etc.) provided on each wheel including the drive wheels 2, and brake actuators connected to the brakes via hydraulic piping. The operation of the braking device 30 is controlled by a brake controller 43 in accordance with the amount of depression of a brake pedal (not shown) by the driver or a control command (brake request) from the ACC controller 41.

[0017] The surroundings detection device 50 is configured to detect the surrounding conditions of the vehicle 1, in particular, targets such as a preceding vehicle that are present in front of the vehicle 1. The surroundings detection device 50 is configured, for example, with a camera (for example, a monocular camera) that captures an image of the area in front of the vehicle 1, or a millimeter-wave radar, a sonar sensor, a LiDAR (Light Detection and Ranging), or the like that detects obstacles in front of the vehicle 1. The detection of the surrounding conditions by the surroundings detection device 50 is dynamically performed at a predetermined measurement period, and information on obstacles in front detected by the surroundings detection device 50 is input to the ACC controller 41.

[0018] The HMI (Human Machine Interface) device 51 is configured to provide information to the occupants of the vehicle 1 in response to control signals from the ACC controller 41. The HMI device 51 has, for example, a liquid crystal display, indicator lights, speakers, etc. arranged on an instrument panel at the front of the vehicle 1, and provides information such as instructions, warnings, and guidance to the occupants, for example, the driver, visually and / or audibly. When the ACC function is operating, the HMI device 51 displays information indicating that the ACC is operating.

[0019] The wheel speed sensor 52 detects the rotation speed of each wheel of the vehicle 1 and transmits the detection result to the TM controller 40 and the ACC controller 41. The vehicle speed of the vehicle 1 is calculated based on the rotation speed of each wheel detected by the wheel speed sensor 52. Note that, for simplicity, only one wheel speed sensor 52 is shown in FIG. 1, but in reality, a wheel speed sensor 52 is provided corresponding to each wheel.

[0020] The TM controller 40, ACC controller 41, engine controller 42, and brake controller 43 are each composed of a computer including a ROM that stores programs and data, a CPU that performs arithmetic processing, a RAM that stores dynamic data and arithmetic processing results, an input / output interface, etc. The TM controller 40, ACC controller 41, engine controller 42, and brake controller 43 are connected to each other via an in-vehicle network (such as a CAN) so that they can communicate with each other.

[0021] The TM controller 40 is configured to change the gear position of the automatic transmission 20 according to a preset shift map based on driving conditions such as vehicle speed, accelerator opening, throttle opening, and engine speed when the selector lever (not shown) is switched to D range. The accelerator opening is the amount of depression of the accelerator pedal operated by the driver to accelerate or decelerate, and the throttle opening is the degree of opening of the throttle valve. Because engine speed changes as the accelerator opening and throttle opening change, it can be said that there is a correlation between the accelerator opening, throttle opening, and engine speed. The shift map defines shift conditions for gradually shifting the gear position of the automatic transmission 20 (shifting up or down). For example, when the combination of the vehicle speed of the vehicle 1 detected by the wheel speed sensor 52 and the accelerator opening exceeds a shift line set in the shift map, the TM controller 40 determines that the shift condition is met and controls the automatic transmission 20 to perform a shift operation. For example, the shift map for downshifting is set so that when a first shifting condition is met, the automatic transmission 20 is shifted from first gear to neutral, and when a second shifting condition is met, the automatic transmission 20 is shifted from second gear to first gear.

[0022] Note that the TM controller 40 may be configured to perform gear shifting operations based on the vehicle speed and throttle opening, without using the accelerator opening, when the ACC function is being executed and the driver is not depressing the accelerator pedal. That is, since the accelerator opening and the throttle opening are correlated as described above, the TM controller 40 can determine whether the gear shift conditions are met based on the combination of the vehicle speed and the accelerator opening or the throttle opening.

[0023] The ACC controller 41 is configured to execute an ACC function based on the surrounding conditions of the vehicle 1 detected by the surroundings detection device 50, in which the vehicle 1 travels at a constant speed according to a set vehicle speed when there is no preceding vehicle in the lane in which the vehicle 1 is traveling, and in which the vehicle follows the preceding vehicle when there is a preceding vehicle. In order to execute the ACC function, the ACC controller 41 controls acceleration and deceleration of the vehicle 1 based on user settings (set vehicle speed and set inter-vehicle distance) input by the driver when the ACC function is turned on by a switch operation by the driver. The ACC function is a so-called all-speed range ACC function that operates within a predetermined vehicle speed range (for example, approximately 0 km / h to approximately 120 km / h). The ACC function is configured to temporarily stop operation when the accelerator pedal is operated, and to stop operation when the brake pedal is operated.

[0024] When there is no preceding vehicle in the lane in which the vehicle 1 is traveling, the ACC controller 41 outputs acceleration / deceleration commands to the engine controller 42 and the brake controller 43 so that the vehicle 1 travels at a constant speed according to a set vehicle speed (target vehicle speed). Furthermore, when the ACC function is on and there is a preceding vehicle in the lane in which the vehicle 1 is traveling, the ACC controller 41 outputs acceleration / deceleration commands to the engine controller 42 and the brake controller 43 so that the vehicle travels while maintaining a set inter-vehicle distance. In this way, the ACC controller 41 is configured to execute the ACC function (constant speed traveling, following traveling, decelerating to a stop, and restarting) by controlling the operation of the engine 10 and the braking device 30.

[0025] When the vehicle 1 is following a preceding vehicle using an ACC function compatible with all vehicle speed ranges, the ACC controller 41 controls the engine controller 42 and the brake controller 43 so that when the preceding vehicle decelerates, the vehicle 1 also decelerates to maintain a predetermined inter-vehicle distance, and so that when the preceding vehicle stops, the vehicle 1 also stops. At this time, the TM controller 40 controls the automatic transmission 20 to downshift by gradually switching the gear to a lower gear in accordance with a preset shift map as the vehicle 1 decelerates. The lower the gear set in the automatic transmission 20, the greater the deceleration that occurs in the vehicle 1 due to engine braking.

[0026] While the ACC function is operating, the driver does not operate the pedals to accelerate or decelerate, and it is difficult for the driver to predict the timing of shifts in the automatic transmission 20. Therefore, when the ACC function causes the vehicle 1 to decelerate and stop, if a large deceleration occurs in the vehicle 1 due to a downshift operation of the automatic transmission 20, the change in vehicle behavior will be unexpected for the driver, and the driving feeling will deteriorate.

[0027] Therefore, in the control device of the vehicle 1 according to the present embodiment, when the ACC controller 41 decelerates and stops the vehicle 1 while the ACC function is running, the TM controller 40 executes gear shift correction control to shift the automatic transmission 20 to a neutral state so as to suppress fluctuations in deceleration due to engine braking compared to normal gear shifting operations when the ACC function is not running. Specifically, when decelerating and stopping the vehicle 1, the TM controller 40 shifts the gears of the automatic transmission 20 to lower gears in stages as the vehicle 1 decelerates, skipping the lowest gear including at least first gear, and shifts the automatic transmission 20 to a neutral state. By shifting to the neutral state while avoiding the lowest gear, the occurrence of large engine braking (deceleration) due to the lowest gear is avoided, and the occurrence of deceleration is prevented from causing discomfort to the driver. This allows the automatic transmission 20 to perform a gear shifting operation that provides a comfortable driving feeling.

[0028] The following describes in detail the shift correction control of the automatic transmission 20 in this embodiment when the vehicle 1 decelerates to a stop while the ACC function is being executed. First, referring to FIG. 2, a description will be given of a change in gear position due to a normal shift operation of the automatic transmission 20 when the ACC is not in operation. FIG. 2 is a diagram that schematically shows the change in gear position over time when the vehicle 1 decelerates to a stop when the ACC is not in operation (ACC off). The horizontal axis of FIG. 2 represents time t, and the vertical axis schematically shows the vehicle speed V and the gear position of the automatic transmission 20. As mentioned above, the shift map of the automatic transmission 20 is set taking engine speed into consideration. However, for simplicity, the engine speed is assumed to be constant, and the description will focus on the operation of switching gear positions in response to changes in vehicle speed.

[0029] 2, when the vehicle 1 starts to decelerate at time t0 with the gear position of the automatic transmission 20 set to fourth gear, the condition for shifting from fourth gear to third gear is met at time t1. At this time, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear position from fourth gear to third gear. When the vehicle 1 further decelerates and the condition for shifting from third gear to second gear is met at time t2, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear position from third gear to second gear.

[0030] When the vehicle 1 further decelerates to vehicle speed V2, and a shift condition from second gear to first gear (second shift condition) is met at time t3, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear from second gear to first gear. Thereafter, when the vehicle 1 decelerates to vehicle speed V1, and a shift condition from first gear to neutral (first shift condition) is met at time t4, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear from first gear to neutral. The vehicle speed (first vehicle speed) V1 corresponding to the first shift condition is a low vehicle speed that does not cause the vehicle 1 to stall, for example, approximately 5 km / h. When the vehicle speed drops to 0 in neutral, the vehicle 1 comes to a stop.

[0031] In this way, normally (when the ACC is not operating), the TM controller 40 shifts down the gear of the automatic transmission 20 in stages from 4th gear to 3rd gear to 2nd gear to 1st gear to a lower gear, and then transitions to a neutral state. In contrast, when the ACC is operating, the TM controller 40 performs gear shift correction control to shift the automatic transmission 20 so that the lowest gear (for example, 1st gear) is skipped and the automatic transmission 20 transitions to the neutral state. Through the gear shift correction control, the automatic transmission 20 is changed to the neutral state at the timing (time t4) shown in FIG. 2 or earlier.

[0032] Specifically, the TM controller 40 shifts the automatic transmission 20 from second gear to first gear at a vehicle speed V that is equal to or greater than a first vehicle speed V1 that corresponds to a first shifting condition for shifting from first gear to the neutral state. More specifically, the TM controller 40 shifts the automatic transmission 20 from second gear to first gear at a vehicle speed that is equal to or greater than a first vehicle speed V1 that corresponds to the first shifting condition for shifting from first gear to the neutral state, or at an engine speed that is equal to or greater than the engine speed that corresponds to the first shifting condition.

[0033] The gear shift correction control method will be described in detail below. When the vehicle 1 decelerates and then comes to a stop while the ACC is operating, the TM controller 40 executes the gear shift correction control according to the following first or second method so as to suppress fluctuations in the deceleration rate more than usual and transition the vehicle 1 to the neutral state.

[0034] (1) First method When the gear position of the automatic transmission 20 is set to second gear and a second shift condition for shifting from second gear to first gear is met, the TM controller 40 shifts the automatic transmission 20 from second gear to a neutral state.

[0035] 3, when the ACC controller 41 recognizes a preceding vehicle ahead of the vehicle 1 traveling at a slower speed than the vehicle 1 while the ACC is operating, or when the preceding vehicle that the vehicle 1 is following decelerates, the ACC controller 41 sends a deceleration command to the brake controller 43 (time t0: ACC brake on). As a result, when the vehicle 1 starts to decelerate and a shift condition from fourth gear to third gear is met at time t1, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear from fourth gear to third gear. When the vehicle 1 further decelerates and a shift condition from third gear to second gear is met at time t2, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear from third gear to second gear.

[0036] Furthermore, when the vehicle 1 decelerates to a second vehicle speed V2 and the second shift condition is met at time t3, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear from second gear to neutral. This causes the automatic transmission 20 to transition to the neutral state at an earlier timing than when the ACC is not operating as shown in FIG. 2. When the vehicle speed drops to 0 in the neutral state, the vehicle 1 stops. Thereafter, when the ACC function is turned off by the driver operating a switch or the like, the deceleration command from the ACC controller 41 to the brake controller 43 stops (time t5: ACC brake off).

[0037] (2) Second method When the gear stage of the automatic transmission 20 is set to second gear and a second shifting condition for changing from second gear to first gear is satisfied, the TM controller 40 fixes the automatic transmission 20 to second gear, and when a first shifting condition for changing from first gear to neutral is satisfied, the TM controller 40 changes the automatic transmission 20 from second gear to neutral.

[0038] 4, when the ACC controller 41 recognizes a preceding vehicle ahead of the vehicle 1 traveling at a slower speed than the vehicle 1 while the ACC is operating, or when the preceding vehicle that the vehicle 1 is following decelerates, the ACC controller 41 sends a deceleration command to the brake controller 43 (time t0: ACC brake on). As a result, when the vehicle 1 starts to decelerate and a shift condition from fourth gear to third gear is met at time t1, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear from fourth gear to third gear. When the vehicle 1 further decelerates and a shift condition from third gear to second gear is met at time t2, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the gear from third gear to second gear.

[0039] Thereafter, even if the vehicle 1 decelerates to a second vehicle speed V2 and the second shift condition is satisfied at time t3, the TM controller 40 does not perform a shift operation and maintains the gear position in second gear. As a result, the vehicle 1 continues to decelerate due to the engine braking of second gear. When the vehicle 1 further decelerates to a first vehicle speed V1 and the first shift condition is satisfied at time t4, the TM controller 40 sends a shift command to the automatic transmission 20 to perform a shift operation to switch the automatic transmission 20 from second gear to neutral. When the vehicle speed drops to 0 in neutral, the vehicle 1 stops. Thereafter, when the ACC function is turned off by the driver operating a switch or the like, the deceleration command from the ACC controller 41 to the brake controller 43 stops (time t5: ACC brake off).

[0040] The TM controller 40 can be configured to have only one of the first and second methods as the gear stage switching method for executing the shift correction control. Alternatively, the TM controller 40 may be configured to allow the driver to select either the first or second method as the gear stage switching method for executing the shift correction control, for example, by operating a switch.

[0041] The flow of the gear shift correction control in this embodiment will be described below with reference to the flowchart in Fig. 5. Fig. 5 shows an example of processing related to the gear shift correction control that is executed mainly in the TM controller 40 when the vehicle 1 decelerates and then comes to a stop while the ACC is operating.

[0042] In step S101, the ACC controller 41 determines whether or not a preceding vehicle traveling at a slower speed than the vehicle 1 has been recognized ahead of the vehicle 1, or whether or not the preceding vehicle that the vehicle 1 is following has decelerated. If a positive determination is made in step S101, it is determined that the vehicle 1 needs to decelerate, and the process proceeds to step S102. On the other hand, if a negative determination is made in step S101, this process ends, and constant speed traveling or following traveling using the ACC function continues.

[0043] In step S102, the ACC controller 41 transmits a deceleration command to the brake controller 43 so as to maintain a predetermined inter-vehicle distance (or inter-vehicle time) and follow the preceding vehicle, thereby controlling the deceleration of the vehicle 1. Furthermore, the TM controller 40 switches the gear stage of the automatic transmission 20 to a lower gear stage according to a predetermined shift map as necessary as the vehicle 1 decelerates.

[0044] In step S103, the ACC controller 41 determines whether the preceding vehicle that the vehicle 1 is following has further decelerated and stopped. If it is determined that the preceding vehicle has stopped, the process proceeds to step S104, and if the preceding vehicle has not stopped, the process returns to step S101.

[0045] In step S104, the TM controller 40 determines whether the current gear position of the automatic transmission 20 is second gear. If the current gear position of the automatic transmission 20 is not second gear, that is, if it is third gear or fourth gear, the process proceeds to step S105. In step S105, the TM controller 40 determines whether the vehicle speed and throttle opening of the vehicle 1 satisfy the shift conditions of the downshift shift map. If it is determined that the shift conditions are met, the process proceeds to step S106. In step S104, the TM controller 40 changes the gear position of the automatic transmission 20 to a lower gear position, downshifts, and returns to step S104.

[0046] If it is determined in step S104 that the current gear position of the automatic transmission 20 has been downshifted to second gear, the process proceeds to step S107. In step S107, the TM controller 40 determines whether a change condition for changing the gear position of the automatic transmission 20 from second gear to neutral has been met. Specifically, when the first method is followed, it determines whether a second shift condition for changing from second gear to first gear has been met in the shift map when the ACC is not operating. On the other hand, when the second method is followed, it determines whether a first shift condition for changing from first gear to neutral has been met in the shift map when the ACC is not operating.

[0047] If it is determined that the second shifting condition of the first method or the first shifting condition of the second method is satisfied, the process proceeds to step S108, where the TM controller 40 changes the gear position of the automatic transmission 20 to the neutral state. After the automatic transmission 20 has been changed to the neutral state, when the vehicle 1 stops in step S109, this process ends.

[0048] When the vehicle 1 stops in step S109, the ACC controller 41 may perform brake control (pitching suppression control) to suppress pitching of the vehicle 1. Specifically, when the vehicle 1 is decelerated to a stop while the ACC function is being executed, the ACC controller 41 is configured to perform brake control to temporarily reduce and then increase the braking force when the vehicle speed V of the vehicle 1 decelerates to a first predetermined value. Here, the first predetermined value of the vehicle speed V is the vehicle speed immediately before the vehicle 1 stops, and is set to, for example, approximately 2 km / h to approximately 3 km / h. When the vehicle 1 decelerates due to the brake control and the vehicle speed V reaches a second predetermined value (for example, approximately 1 km / h) at which the vehicle 1 can be considered to be substantially stopped, the braking force is increased to stop the vehicle 1.

[0049] In this case, if the automatic transmission 20 is shifted to the neutral state after adjusting the braking force through the pitching suppression control, fluctuations in deceleration and vehicle speed may become large, which may cause discomfort to the driver. Therefore, it is preferable that the TM controller 40 shifts the automatic transmission 20 from second gear to the neutral state during the gear shift correction control when the vehicle speed V is greater than the first predetermined value described above.

[0050] Specifically, in the case of the first method, the TM controller 40 sets the second vehicle speed V2 corresponding to the second shifting condition to a value greater than the first predetermined value, and in the case of the second method, the TM controller 40 sets the first vehicle speed V1 corresponding to the first shifting condition to a value greater than the first predetermined value. In other words, the first predetermined value of the vehicle speed V at which brake control is performed to suppress pitching when the vehicle 1 is stopped is set to a value smaller than the first vehicle speed V1 and the second vehicle speed V2 that correspond to the shifting conditions for changing the automatic transmission 20 to the neutral state in the shift correction control.

[0051] The control device for vehicle 1 according to the present embodiment described above can achieve the following advantageous effects.

[0052] (1) The control device for vehicle 1 includes an automatic transmission 20 having multiple gear stages, a TM controller 40 configured to control the automatic transmission 20 to change gear stages in accordance with the vehicle speed V of vehicle 1 and the accelerator opening or throttle opening, and an ACC controller 41 configured to execute an ACC function that performs constant speed driving according to a set vehicle speed when there is no preceding vehicle in the lane in which vehicle 1 is traveling, and follows the preceding vehicle when there is a preceding vehicle. When the ACC controller 41 determines to decelerate and stop vehicle 1 while the ACC function is being executed, the TM controller 40 executes gear shift correction control that gradually changes the gear stages of automatic transmission 20 to lower gear stages, skips the lowest gear stage including at least first gear stage, and changes automatic transmission 20 to a neutral state.

[0053] While the ACC function is in operation, the driver does not operate the pedals to accelerate or decelerate, making it difficult to predict the timing of gear changes. Therefore, if a large deceleration occurs due to engine braking when the automatic transmission 20 downshifts, the driver experiences an unexpected change in vehicle behavior, resulting in a poor driving experience. The deceleration due to engine braking is particularly large in lower gears. Therefore, when the vehicle 1 decelerates and stops while the ACC function is in operation, the automatic transmission 20 can be shifted to a neutral state by skipping the lowest gear, including at least first gear, to suppress fluctuations in deceleration due to gear changes. This allows for a comfortable driving experience, i.e., a good braking feel, to be achieved when shifting gears with the automatic transmission 20 in operation.

[0054] (2) In the shift correction control, the TM controller 40 gradually shifts the gear of the automatic transmission 20 up to second gear, and then shifts from second gear to neutral, skipping first gear. By skipping first gear, which has the greatest deceleration due to engine braking, and shifting to neutral, it is possible to suppress fluctuations in deceleration due to gear shifts and improve the driving feel. In addition, by shifting down to second gear in the automatic transmission 20, it is possible to decelerate and stop the vehicle 1 while effectively utilizing the engine braking of second gear.

[0055] (3) The TM controller 40 is configured to change the gear position of the automatic transmission 20 according to a preset shift map based on the vehicle speed V and the accelerator or throttle opening. The shift map is set to change the automatic transmission 20 from first gear to neutral when a first shift condition is met. In the shift correction control, the TM controller 40 changes the automatic transmission 20 from second gear to neutral when the vehicle speed V is equal to or greater than a first vehicle speed V1 corresponding to the first shift condition. This suppresses fluctuations in deceleration due to gear changes, improving the driving feel. In addition, the vehicle 1 can be decelerated and stopped while effectively utilizing the engine brake of second gear.

[0056] (4) As shown in FIG. 2, the shift map is set to shift the automatic transmission 20 from second gear to first gear when the second shift condition is met. In the shift correction control, as shown in FIG. 3, the TM controller 40 shifts the automatic transmission 20 from second gear to neutral when the second shift condition is met (first method). This shifts the automatic transmission 20 to neutral at an earlier timing than in a normal shift operation when the ACC function is not operating, suppressing fluctuations in deceleration due to gear shifts and improving driving feel. If the preceding vehicle starts moving again after the automatic transmission 20 has shifted to neutral, the gear of the automatic transmission 20 can be shifted to first gear to quickly accelerate in line with the movement of the preceding vehicle.

[0057] (5) As shown in FIG. 2, the shift map is set so that the automatic transmission 20 shifts from second gear to first gear when the second shift condition is met. In the shift correction control, as shown in FIG. 4, the TM controller 40 fixes the automatic transmission 20 in second gear when the second shift condition is met, and shifts the automatic transmission 20 from second gear to neutral when the first shift condition is met (second method). By maintaining the automatic transmission 20 in second gear, the engine brake of second gear can be effectively utilized to decelerate the vehicle 1. Furthermore, by shifting the automatic transmission 20 from second gear to neutral, fluctuations in deceleration due to gear changes can be suppressed, improving the driving feel.

[0058] (6) The control device of the vehicle 1 further includes a brake controller 43 that controls the braking force of the braking device 30 in response to a brake request from the ACC controller 41. When the vehicle 1 is decelerated to a stop while the ACC function is being executed, the ACC controller 41 is configured to execute brake control (pitching suppression control) that temporarily reduces and then increases the braking force if the vehicle speed V of the vehicle 1 decelerates to a first predetermined value. In the gear shift correction control, the TM controller 40 shifts the automatic transmission 20 from second gear to neutral at a vehicle speed (first vehicle speed V1 or second vehicle speed V2) greater than the first predetermined value. As a result, the automatic transmission 20 is shifted to neutral before the pitching suppression control is executed when the vehicle 1 decelerates to a stop, thereby suppressing vehicle speed fluctuations of the vehicle 1 and improving the driving feel.

[0059] -Second embodiment- A control device for a vehicle 1 according to a second embodiment of the present invention will be described below. The basic configuration of the control device for a vehicle 1 according to the second embodiment is the same as that of the first embodiment described above. Differences from the first embodiment will be mainly described below.

[0060] In the first embodiment described above, in the gear shift correction control while the ACC function is operating, when the vehicle 1 decelerates and stops due to the ACC function, the automatic transmission 20 skips the first gear and changes to the neutral state. In this case, a deceleration drop occurs that corresponds to engine braking of the first gear of the automatic transmission 20.

[0061] Therefore, in this embodiment, brake control is performed to compensate for the loss of deceleration caused by changing the automatic transmission 20 to the neutral state. Specifically, when the vehicle 1 is decelerated to a stop while the ACC function is being executed, if the automatic transmission 20 is changed to the neutral state in the gear shift correction control, the ACC controller 41 is configured to increase the brake request for a predetermined time compared to when the gear shift correction control is not performed.

[0062] 3, when the second shift condition is satisfied at time t3 as described above, the gear position of the automatic transmission 20 is changed from second gear to neutral. At the same time, the ACC controller 41 transmits a corrective brake request to the brake controller 43 to increase the deceleration for a predetermined time compared to when the shift correction control is not performed. In this case, the corrective brake request is preferably designed to generate deceleration equivalent to the engine brake of first gear.

[0063] For example, the ACC controller 41 sets the corrective brake request so as to generate a corrective deceleration that is increased by a predetermined amount relative to the deceleration required for stopping the vehicle while maintaining a predetermined inter-vehicle distance (inter-vehicle time) from the preceding vehicle by the ACC function when the shift correction control is not performed. Alternatively, the corrective brake request may be set so as to generate a corrective deceleration that is increased by a predetermined percentage relative to the required deceleration.

[0064] The ACC controller 41 transmits a correction brake request for generating a correction deceleration for a predetermined time from time t3 to the brake controller 43. After the predetermined time has elapsed, the ACC function returns to normal brake control.

[0065] The control device for vehicle 1 according to the present embodiment described above can achieve the following advantageous effects in addition to the advantageous effects of the first embodiment described above.

[0066] The control device of the vehicle 1 further includes a brake controller 43 that controls the braking force of the braking device 30 in response to a brake request from the ACC controller 41. When the automatic transmission 20 is shifted to a neutral state during the shift correction control to decelerate and stop the vehicle 1 while the ACC function is being executed, the ACC controller 41 increases the brake request for a predetermined time compared to when the shift correction control is not executed. By shifting to a neutral state while skipping the lowest gear, including at least the first gear, during the shift correction control, engine braking of the lowest gear is not generated. Therefore, by increasing the brake request to compensate for the deceleration due to engine braking, it is possible to suppress fluctuations in deceleration due to gear shifts and prevent deceleration slippage caused by the ACC function. After increasing the brake request for a predetermined time, brake control is performed using normal ACC function feedback control. Because the increase in the brake request is limited, unnecessary interference with the ACC function feedback control can be suppressed.

[0067] -Variations- (1) In the above-described embodiment, the gear shift correction control while the ACC function is operating is configured to skip first gear as the lowest gear of the automatic transmission 20. However, this is not limited to this, and the gear shift correction control may be configured to skip second gear as well as first gear as the lowest gear of the automatic transmission 20. In this case, for example, in the example shown in FIG. 3, when the vehicle speed V decreases and the condition for shifting from third gear to second gear is met at time t2, the TM controller 40 changes the gear of the automatic transmission 20 from third gear to neutral.

[0068] In this case, the automatic transmission 20 skips the second and first gears and is changed to the neutral state, so the ACC controller 41 may execute brake control to compensate for the deceleration loss equivalent to the engine braking of the second and first gears of the automatic transmission 20, as in the second embodiment described above.

[0069] (2) In the above-described embodiment, the gear position of the automatic transmission 20 is changed to the neutral state when the first shift condition or the second shift condition is met according to a preset shift map for when the ACC is not operating. However, this is not limited to this, and when the vehicle 1 decelerates and stops while the ACC is operating, the shift condition for changing the gear position of the automatic transmission 20 to the neutral state may be changed from the shift condition set in the shift map for when the ACC is not operating.

[0070] For example, a third shifting condition for shifting the gear position of the automatic transmission 20 from second gear to neutral may be set in a region where the combination of the throttle opening and the vehicle speed is between the first shifting condition and the second shifting condition. In this case, for example, in the example shown in Fig. 4, when the vehicle speed V of the vehicle 1 decreases to a third vehicle speed that is smaller than the second vehicle speed V2 and larger than the first vehicle speed V1, the third shifting condition is met and the gear position of the automatic transmission 20 is shifted from second gear to neutral.

[0071] (3) In the above-described embodiment, the automatic transmission 20 has been described as an AMT-type transmission, but the present invention is not limited to this. For example, a DCT (Dual Clutch Transmission) type transmission may be used as the automatic transmission 20. That is, the present invention can employ various automatic transmissions that have multiple gears and are capable of automatically changing gears. Furthermore, in the above-described embodiment, an example has been described in which the gear position of the automatic transmission 20 is changed from fourth gear to neutral, but the automatic transmission 20 may be configured to have a gear higher than fourth gear, for example, fifth gear.

[0072] Although several embodiments of the present invention have been described above, it should be noted that the present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the present invention. [Explanation of symbols]

[0073] 1 vehicle 10 Engine 20 Automatic transmission 30 Braking device 40 Transmission (TM) Controller 41 ACC controller 42 Engine Controller 43 Brake controller

Claims

1. an automatic transmission having a plurality of gear stages; a transmission controller configured to control the automatic transmission to change gears in response to a vehicle speed and an accelerator or throttle opening; an ACC controller configured to execute an ACC function of driving the vehicle at a constant speed according to a set vehicle speed when there is no preceding vehicle in the lane in which the vehicle is traveling, and following the preceding vehicle when there is a preceding vehicle; Equipped with When the ACC controller determines that the vehicle is to decelerate and stop while the ACC function is being executed, the transmission controller executes shift correction control to gradually change the gear stage of the automatic transmission to a lower gear stage, skipping a lowest gear stage including at least first gear stage, and change the automatic transmission to a neutral state.

2. 2. The vehicle control device according to claim 1, wherein in the shift correction control, the transmission controller changes the gear position of the automatic transmission stepwise up to second gear, and then changes from second gear to the neutral state by skipping first gear.

3. the transmission controller is configured to change the gear position of the automatic transmission in accordance with a preset shift map based on the vehicle speed and the accelerator opening or the throttle opening, and the shift map is set so as to shift the automatic transmission from the first gear position to the neutral state when a first shift condition is established; 2. The vehicle control device according to claim 1, wherein in the shift correction control, the transmission controller shifts the automatic transmission from second gear to the neutral state at a vehicle speed equal to or higher than the vehicle speed corresponding to the first shift condition.

4. the shift map is set so as to shift the automatic transmission from the second gear to the first gear when a second shift condition is satisfied, 4. The vehicle control device according to claim 3, wherein in the shift correction control, the transmission controller changes the automatic transmission from the second speed stage to the neutral state when the second shift condition is satisfied.

5. the shift map is set so as to shift the automatic transmission from the second gear to the first gear when a second shift condition is satisfied, 4. The vehicle control device according to claim 3, wherein in the shift correction control, the transmission controller fixes the automatic transmission to the second gear when the second shift condition is satisfied, and changes the automatic transmission from the second gear to the neutral state when the first shift condition is satisfied.

6. a brake controller that controls the braking force of a braking device in response to a brake request from the ACC controller; the ACC controller is configured to execute brake control to temporarily reduce and then increase the braking force when a vehicle speed of the vehicle is reduced to a predetermined value when the vehicle is decelerated to a stop while the ACC function is being executed, 4. The vehicle control device according to claim 3, wherein in the shift correction control, the transmission controller shifts the automatic transmission from the second gear to the neutral state when the vehicle speed is greater than the predetermined value.

7. a brake controller that controls the braking force of a braking device in response to a brake request from the ACC controller; 2. The vehicle control device according to claim 1, wherein when the automatic transmission is changed to the neutral state in the gear shift correction control during deceleration and stopping of the vehicle while the ACC function is being executed, the ACC controller increases the brake request for a predetermined time compared to when the gear shift correction control is not executed.

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