Travel control device

Abstract

To achieve safe traveling without providing an occupant with unnecessary fear.SOLUTION: A travel control device comprises: an information acquisition part 20 that acquires traveling environment information on a surrounding area including an area anterior to a driver's own vehicle; a detection part 11 that detects an area where a rising slope of a very short road such as an overbridge becomes gentle, on the basis of the acquired traveling environment information; and a vehicle speed control part 13 that suppresses the unnecessary acceleration and deceleration of the driver's own vehicle, which are generated on the basis of an integrated value of deviation between the acceleration of the driver's own vehicle and target acceleration, in the area where the rising slope of the very short road becomes gentle.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cruise control device. [Background technology]

[0002] A known vehicle driving control device is cruise control, which sets, for example, a target engine torque or a target rotation speed of the input shaft of an automatic transmission for each calculation cycle according to the difference between the vehicle speed set by the driver and the vehicle's own speed, thereby controlling the vehicle speed to converge to a target vehicle speed set based on the set vehicle speed.

[0003] With this type of cruise control, when the vehicle approaches a road surface with a high driving load, such as an uphill road, while driving using cruise control and the vehicle speed drops, the engine control increases the throttle valve opening to increase engine output in order to immediately bring the vehicle speed to the target vehicle speed, while the gear ratio is shifted down to increase torque and accelerate the vehicle, thereby preventing the vehicle speed from dropping.

[0004] For example, one such technology is disclosed that includes a control unit that controls the operation of a drive motor that outputs driving force for the vehicle, and the control unit can switch between a normal mode in which the acceleration and deceleration of the vehicle are controlled in accordance with acceleration and deceleration operations by the driver, and a cruise control mode in which the vehicle speed is maintained at a target vehicle speed by controlling the torque of the drive motor without the driver's acceleration and deceleration operations.If, while the cruise control mode is being executed, it is determined that the vehicle has entered a flat or uphill road from a downhill road, or if it is determined that the vehicle has entered a downhill road from a flat or uphill road, an integrated value adjustment process is executed to adjust the integrated value of the deviation between the vehicle speed and the target vehicle speed in integral control so that the absolute value of the integrated value becomes smaller.This technology prevents the vehicle behavior from becoming unstable due to changes in the gradient of the road while the cruise control mode is being executed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-129346 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology described in Patent Document 1 aims to prevent vehicle behavior from becoming unstable due to changes in the gradient of the road while the cruise control mode is being executed, and if it is determined that the vehicle has entered a flat or uphill road from a downhill road while the cruise control mode is being executed, or if it is determined that the vehicle has entered a downhill road from a flat or uphill road, it executes an integrated value adjustment process to adjust the integrated value of the deviation between the vehicle speed and the target vehicle speed in integral control so that the absolute value of the integrated value of the deviation becomes smaller. However, it is not intended to prevent unnecessary acceleration of the vehicle before the vehicle enters a downhill road from an uphill road, which may cause fear to the occupants, and there is no description or suggestion whatsoever of specific measures to prevent unnecessary acceleration of the vehicle before the vehicle enters a downhill road from an uphill road.

[0007] Incidentally, cruise control has a gradient estimation function that estimates the gradient using acceleration sensors provided at the front and rear of the vehicle. However, the gradient estimation function uses a first-order lag filter to remove external noise, and this first-order lag filter causes the estimated gradient to be earlier than the actual gradient on which the vehicle is currently traveling. As a result, for example, even though the vehicle has just started to ascend an uphill road, the road is estimated to be flat, causing the vehicle speed to be reduced, or even though the vehicle is traveling near the top of an uphill road, the road is estimated to be an uphill gradient, causing the vehicle speed to be accelerated.

[0008] Furthermore, cruise control has an acceleration feedback offset function for eliminating deviations between the target acceleration and the acceleration of the vehicle due to disturbances while the vehicle is running under cruise control. However, although the feedback offset function causes the vehicle's acceleration to reach the target acceleration, the feedback offset is an integral term in integral control and changes slowly, resulting in the vehicle accelerating more than necessary at points where it should be slowing down, such as near the top of an uphill road.

[0009] Therefore, the above phenomenon has posed a problem in that it can cause occupants to feel fear as the vehicle accelerates in places where they cannot see what is ahead, such as near the top of an uphill road.

[0010] Therefore, the present invention has been made in consideration of the above-mentioned problems, and has an object to provide a driving control device that realizes safe driving without giving unnecessary fear to the occupants. [Means for solving the problem]

[0011] Form 1: One or more embodiments of the present invention propose a driving control device that includes an information acquisition unit that acquires information about the surrounding driving environment including the front of the vehicle, a detection unit that detects areas where the uphill gradient of an extremely short road, such as an overpass, becomes gentle based on the acquired driving environment information, and a vehicle speed control unit that suppresses unnecessary acceleration / deceleration of the vehicle that occurs based on the integrated value of the deviation between the acceleration of the vehicle and a target acceleration in areas where the uphill gradient of the extremely short road becomes gentle.

[0012] Form 2: One or more embodiments of the present invention propose a driving control device that includes an acceleration control unit that controls the acceleration of the vehicle by integral control based on the integrated value of the deviation between the acceleration of the vehicle and a target acceleration, and the vehicle speed control unit controls the integral control component in the acceleration control unit to be clear in areas where the uphill gradient of the extremely short road becomes gentle.

[0013] Form 3: One or more embodiments of the present invention propose a driving control device characterized in that the area where the uphill gradient becomes gentle is defined according to the distance from the vehicle to the top of the extremely short road, which is acquired by the information acquisition unit.

[0014] Form 4: One or more embodiments of the present invention propose a driving control device that includes an acceleration control unit that controls the acceleration of the vehicle by integral control based on the integrated value of the deviation between the acceleration of the vehicle and a target acceleration, and the vehicle speed control unit controls the integral control component in the acceleration control unit to clear when the difference between the acceleration of the vehicle and the target acceleration becomes zero or less.

[0015] Form 5: One or more embodiments of the present invention propose a driving control device that includes an estimation unit that filters the sensor output of acceleration sensors installed in front and behind the vehicle using a first-order delay time constant to estimate the uphill gradient of the extremely short road, and the vehicle speed control unit gradually decreases the value of the first-order delay time constant in areas where the uphill gradient of the extremely short road becomes gentler, depending on the distance between the vehicle and the top of the extremely short road. [Effects of the Invention]

[0016] According to one or more embodiments of the present invention, it is possible to achieve safe driving without causing unnecessary fear to passengers. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing the configuration of a cruise control device according to a first embodiment of the present invention. [Figure 2] 1 is a diagram showing the configuration of a cruise control ECU according to a first embodiment of the present invention. [Figure 3] 3 is a flowchart showing the processing of the cruise control device according to the first embodiment of the present invention. FIG. [Figure 4]FIG. 2 is a diagram schematically illustrating the processing of the cruise control device according to the first embodiment of the present invention. [Figure 5] FIG. 4 is a diagram showing the configuration of a cruise control device according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing the configuration of a cruise control ECU according to a second embodiment of the present invention. [Figure 7] FIG. 6 is a flowchart showing the processing of a cruise control device according to a second embodiment of the present invention. [Figure 8] FIG. 6 is a diagram schematically illustrating a processing state of a cruise control device according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing the configuration of a cruise control device according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a diagram showing the configuration of a cruise control ECU according to a third embodiment of the present invention. [Figure 11] FIG. 10 is a flowchart showing the processing of a driving control device according to a third embodiment of the present invention. [Figure 12] FIG. 10 is a diagram schematically illustrating a processing state of a cruise control device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] <Embodiment> A driving control device 1 according to this embodiment will be described with reference to FIGS. 1 to 12. FIG. First Embodiment A driving control device 1 according to this embodiment will be described with reference to FIGS. 1 to 4. FIG.

[0019] <Configuration of driving control device 1> As shown in FIG. 1, the driving control device 1 according to this embodiment is configured to include a driving control ECU (Electronic Control Unit) 10, an information acquisition unit 20, a vehicle speed sensor 30, an engine ECU 50, an engine Act 51, a brake control ECU 60, and a brake Act 61.

[0020] The driving control ECU 10 executes control related to the driving of the vehicle. Furthermore, the cruise control ECU 10 suppresses unnecessary acceleration of the vehicle in an area where the upward gradient of an extremely short uphill road becomes gentle. An example of an "extremely short road" is a sloped road with a series of short uphill and downhill sections of several tens to several hundred meters, such as an overpass. The area where the uphill gradient becomes gentle is defined according to the distance from the vehicle to the top of the very short road, which is acquired by an information acquisition unit described later. Specifically, the cruise control ECU 10 controls the acceleration control unit (described later) to clear the integral control component in the area where the uphill gradient of an extremely short road becomes gentle. Specifically, when the difference between the acceleration of the host vehicle and the target acceleration becomes zero or less, the cruise control ECU 10 performs control to clear the integral control component in the acceleration control section, which will be described later. The cruise control ECU 10 is connected to an information acquisition unit 20, a vehicle speed sensor 30, an engine ECU 50, and a brake control ECU 60, which will be described later. Of these, the information acquisition unit 20 and the vehicle speed sensor 30 are directly connected to the cruise control ECU 10 . Furthermore, the engine ECU 50 and the brake control ECU 60 transmit and receive information to and from the cruise control ECU 10 via a CAN (Control Area Network).

[0021] The information acquisition unit 20 acquires information about the driving environment around the vehicle, including the area ahead of the vehicle. The information acquisition unit 20 incorporates an imaging element such as a CCD (Charge Coupled Device) or a CIS (CMOS Image Sensor), and outputs images (including moving images and still images) of the surrounding area including the area ahead of the vehicle captured by the imaging element. It is preferable that the information acquisition unit 20 is configured with both an optical imaging element and a near-infrared imaging element so that it can acquire information about the surrounding driving environment, including the area ahead of the vehicle, regardless of day or night.

[0022] The vehicle speed sensor 30 detects the traveling speed (vehicle speed) of the host vehicle, and outputs a signal indicating the vehicle speed to the cruise control ECU 10.

[0023] The engine ECU 50 is connected to an engine Actuator (Act) 51 . The engine Act51 is an actuator for changing the operating state of the internal combustion engine. In this embodiment, the internal combustion engine is a gasoline fuel injection, spark ignition, multi-cylinder engine, and is equipped with a throttle valve for adjusting the amount of intake air. In this embodiment, a vehicle equipped with an internal combustion engine is described as an example, but the present invention can also be applied to an EV vehicle, an HV vehicle, or the like.

[0024] The brake control ECU 60 is connected to a brake Actuator 61 . The brake Act 61 is provided in a hydraulic circuit between a master cylinder that pressurizes hydraulic oil by the depression force of the brake pedal and friction brake mechanisms provided on the left, right, front and rear wheels.

[0025] <Configuration of driving control ECU 10> As shown in FIG. 2, the cruise control ECU 10 according to this embodiment includes a detection unit 11, an acceleration control unit 12, and a vehicle speed control unit 13.

[0026] The detection unit 11 performs image analysis of the traveling environment information acquired by the information acquisition unit 20 to detect extremely short roads such as overpasses. Furthermore, the detection unit 11 performs image analysis of the driving environment information acquired by the information acquisition unit 20, and calculates the distance between the vehicle and the vicinity of the top of the very short road.

[0027] The acceleration control unit 12 controls the acceleration of the host vehicle by integral control based on the integrated value of the deviation between the acceleration of the host vehicle and the target acceleration. For example, when the host vehicle is an electric vehicle, the acceleration control unit 12 calculates a torque command value for the drive motor so that the vehicle speed of the host vehicle approaches the target vehicle speed, and controls the torque of the drive motor to the torque command value. More specifically, the acceleration control unit 12 controls the torque of the drive motor using, for example, feedforward control based on the acceleration of the vehicle itself and feedback control (for example, PID control) based on the deviation between the acceleration of the vehicle itself and a target acceleration, and calculates a torque command value for commanding this torque to the drive motor. Here, the torque command value includes a feedforward control component based on the acceleration of the vehicle, a proportional control component based on the magnitude of the deviation between the acceleration of the vehicle and the target acceleration, a differential / integral control component based on the magnitude of the change in the deviation, and an integral control component based on the integrated value of the deviation, and of these, the integral control component based on the magnitude of the change in the deviation has the characteristic of changing slowly.

[0028] The vehicle speed control unit 13 suppresses unnecessary acceleration of the vehicle in an area where the upward gradient of an extremely short uphill road becomes gentle. Specifically, the vehicle speed control unit 13 controls the acceleration control unit 12 so as to clear the integral control component in the area where the uphill gradient of the extremely short road becomes gentle. Specifically, when the difference between the acceleration of the vehicle and the target acceleration becomes zero or less, the vehicle speed control unit 13 controls the integral control component in the acceleration control unit 12 to be cleared.

[0029] <Processing of driving control device 1> The processing of the driving control device 1 according to this embodiment will be described with reference to FIGS.

[0030] The host vehicle starts traveling with ACC (Adaptive Cruise Control) applied (step S101). Specifically, for example, in (1) of FIG. 4, the cruise control device 1 sets the set vehicle speed (SET vehicle speed) to 50 km / h and causes the host vehicle to start traveling with ACC (Adaptive Cruise Control) applied.

[0031] For example, the vehicle starts traveling uphill in (2) of FIG. 4 (step S102). At this time, the vehicle speed drops to, for example, about 49.5 km / h due to the influence of the uphill gradient. Then, for example, in FIG. 4(2A), the acceleration feedback offset (AFBOffset) value starts to increase, but because this timing is slightly delayed compared to the actual gradient, the vehicle speed of the vehicle is affected by the uphill gradient and further decreases, for example, to about 47 km / h. In addition, in (3) of FIG. 4, due to the increased acceleration feedback offset value, the vehicle speed of the vehicle increases to 49 km / h, which is close to the set vehicle speed (SET vehicle speed), through control by the acceleration control unit 12 based on the deviation between the acceleration of the vehicle and the target acceleration (acceleration feedback offset control). Furthermore, for example, in (3A) of FIG. 4, even if the vehicle speed of the host vehicle exceeds the set vehicle speed, the increased acceleration feedback offset value does not immediately decrease, and the vehicle speed of the host vehicle increases to about 51 km / h due to the control (acceleration feedback offset control) of acceleration control unit 12 based on the deviation between the acceleration of the host vehicle and the target acceleration. Furthermore, in (4) of FIG. 4, even if the vehicle speed of the host vehicle exceeds the set vehicle speed, the increased acceleration feedback offset value does not immediately decrease, and the vehicle speed of the host vehicle increases to about 52 km / h due to the control (acceleration feedback offset control) of the acceleration control unit 12 based on the deviation between the acceleration of the host vehicle and the target acceleration.

[0032] The acceleration control unit 12 determines whether the detection unit 11 has detected an area with a gentle uphill gradient on an extremely short road, such as an overpass, from the driving environment information acquired by the information acquisition unit 20 (step S103). Specifically, the acceleration control unit 12 detects the vicinity of the top of an extremely short road such as an overpass from the image information ahead of the vehicle acquired by the information acquisition unit 20 in the detection unit 11, and determines whether the distance from the current position of the vehicle ((4) in Figure 4) to the vicinity of the top of the extremely short road such as an overpass is a predetermined distance, in other words, whether the current position of the vehicle is the control start point. Here, the "predetermined distance" can be, for example, 3 m or more and less than 15 m, taking into consideration the gradient of an extremely short section such as an overpass. Then, when the detection unit 11 determines that it is unable to detect an area with a gentle uphill gradient on an extremely short road such as an overpass from the driving environment information acquired by the information acquisition unit 20 ("NO" in step S103), the acceleration control unit 12 transitions to standby mode.

[0033] On the other hand, if the acceleration control unit 12 determines that the detection unit 11 has detected an area where the uphill gradient of an extremely short road, such as an overpass, becomes gentle from the driving environment information acquired by the information acquisition unit 20 ("YES" in step S103), the vehicle speed control unit 13 executes control to clear the integral term of the acceleration feedback offset (AFBOffset) (step S105). This control clears the acceleration feedback offset value, so the vehicle speed decelerates from, for example, about 52 km / h in FIG. 4(4) to the set vehicle speed of 50 km / h in FIG. 4(5). In FIG. 4 (5A), the vehicle reaches a gentle gradient area near the top of the slope, causing the vehicle speed to slightly exceed the set vehicle speed, at about 50.5 km / h.

[0034] After the host vehicle starts climbing, the acceleration control unit 12 sets the target acceleration to 0 [m / s 2 ] is determined (step S104). The acceleration control unit 12 determines whether the target acceleration is 0 [m / s 2 If it is determined that the setting is not "YES" ("NO" in step S104), the process goes to standby mode.

[0035] On the other hand, the acceleration control unit 12 determines whether the target acceleration is 0 [m / s 2 If it is determined that the integral term of the acceleration feedback offset is equal to or greater than the acceleration feedback offset (YES in step S104), the vehicle speed control section 13 executes control to clear the integral term of the acceleration feedback offset (step S105). In this case, the vehicle speed of the host vehicle decelerates from, for example, 52 km / h in FIG. 4(4) to 50 km / h in FIG. 4(5), and the vehicle speed drops to 51 km / h in FIG. 4(6) due to the influence of the downhill gradient. However, the acceleration feedback offset value becomes a negative value, so the vehicle speed is prevented from exceeding the limit excessively. In FIG. 4 (6A), the vehicle speed settles at the set vehicle speed due to the negative acceleration feedback offset value, and the acceleration feedback offset value approaches zero.

[0036] When the detection unit 11 determines from the image information of the area ahead of the vehicle acquired by the information acquisition unit 20 that the vehicle has finished descending a slope (step S106), the vehicle speed control unit 13 terminates the processing while continuing ACC driving (step S107).

[0037] <Actions and Effects> As explained above, the driving control device 1 according to this embodiment includes an information acquisition unit 20 that acquires information about the surrounding driving environment including the area ahead of the vehicle, a detection unit 11 that detects areas where the upward gradient of an extremely short road, such as an overpass, becomes gentle based on the driving environment information acquired by the information acquisition unit 20, an acceleration control unit 12 that controls the acceleration of the vehicle by integral control based on the integrated value of the deviation between the acceleration of the vehicle and a target acceleration, and a vehicle speed control unit 13 that suppresses unnecessary acceleration and deceleration that occur based on the integrated value of the deviation between the acceleration of the vehicle and a target acceleration in areas where the upward gradient of an extremely short road becomes gentle. In other words, based on the driving environment information acquired by the information acquisition unit 20, the detection unit 11 detects areas where the uphill gradient of an extremely short road, such as an overpass, becomes gentle, and the vehicle speed control unit 13 sends a control signal to the acceleration control unit 12 in areas where the uphill gradient of an extremely short road becomes gentle, so as to suppress unnecessary acceleration and deceleration that occurs based on the integrated value of the deviation between the acceleration of the vehicle and the target acceleration. This allows for safe driving without causing unnecessary fear to the passengers.

[0038] Furthermore, the vehicle speed control unit 13 of the cruise control device 1 according to this embodiment controls the integral control component in the acceleration control unit 12 to be clear in an area where the uphill gradient of an extremely short road becomes gentle. When there is a deviation between the target acceleration and the acceleration of the subject vehicle, the feedback offset in the acceleration feedback offset function that eliminates the deviation is an integral term of integral control and changes slowly. This causes a problem in that the vehicle may accelerate more than necessary at points where it should be slowing down, such as near the top of an uphill road. However, the vehicle speed control unit 13 according to this embodiment controls the integral control component in the acceleration control unit 12 to be clear in the region where the uphill gradient becomes gentle before reaching the top of the very short road, thereby making it possible to suppress unnecessary acceleration that occurs based on the integrated value of the deviation between the acceleration of the vehicle and the target acceleration. The above control is particularly effective on extremely short roads with steep uphill sections.

[0039] Furthermore, when the difference between the acceleration of the host vehicle and the target acceleration becomes zero or less, the vehicle speed control unit 13 of the cruise control device 1 according to this embodiment controls the integral control component in the acceleration control unit 12 to be cleared. In other words, on an extremely short road with a relatively long uphill section, as described above, the difference between the acceleration of the vehicle and the target acceleration may become zero or less before the vehicle reaches a distance from the top of the extremely short road that clears the integral control component in the acceleration control unit 12. When the difference between the vehicle's acceleration and the target acceleration is zero or less, there is no need to accelerate the vehicle in the first place, but because the feedback offset is an integral term of integral control and changes slowly, control that accelerates the vehicle is activated. In such a case, even if the vehicle has not yet reached the distance from the top of the extremely short road that would clear the integral control component in acceleration control unit 12, it is possible to suppress unnecessary acceleration that occurs based on the integrated value of the deviation between the acceleration of the vehicle and the target acceleration by controlling the integral control component in acceleration control unit 12 to be clear.

[0040] <Second embodiment> A driving control device 1A according to this embodiment will be described with reference to FIGS.

[0041] <Configuration of driving control device 1A> As shown in FIG. 5, the driving control device 1A according to this embodiment is configured to include a driving control ECU (Electronic Control Unit) 10A, an information acquisition unit 20, an acceleration sensor 40, an engine ECU 50, an engine Act 51, a brake control ECU 60, a brake Act 61, and a wheel speed sensor 70. Note that components with the same reference numerals as those in the first embodiment have the same functions, and therefore detailed descriptions thereof will be omitted.

[0042] The cruise control ECU 10A executes control related to the vehicle's travel, and suppresses unnecessary acceleration of the host vehicle in areas where the uphill gradient of an extremely short road becomes gentle. In this embodiment, the cruise control ECU 10A detects an area where the upward gradient of an extremely short road, such as an overpass, becomes gentle, based on the traveling environment information acquired by the information acquisition unit 20. In this embodiment, the driving control ECU 10A executes control to gradually decrease the value of the first-order delay time constant used in the estimation unit described later in accordance with the distance between the vehicle detected by the detection unit 11 and the vicinity of the top of the extremely short road in the region where the uphill gradient of the extremely short road becomes gentle. When this control is to be terminated, control is executed to gradually increase (return to original) the value of the first-order delay time constant used in the estimation unit (described later) as the downhill gradient of the extremely short road becomes gentler.

[0043] The acceleration sensors 40 are provided in pairs in the longitudinal direction of the vehicle, and output a voltage corresponding to the acceleration received in the longitudinal direction of the vehicle. Here, the acceleration that the acceleration sensor 40 receives in the longitudinal direction of the vehicle is the sum of the acceleration due to the longitudinal acceleration movement of the vehicle and the acceleration due to gravity caused by the longitudinal tilt of the vehicle. The acceleration sensor 40 may be any of various well-known types, such as an electrostatic type, a piezoelectric type, or a semiconductor strain gauge type.

[0044] The wheel speed sensor 70 detects the rotation speed of each wheel as a signal. Specifically, the wheel speed sensor 70 has a gear-shaped rotor attached to a rotating part such as a drive shaft, axle hub, or brake drum, and a sensor consisting of a coil and magnetic poles is installed around the outer periphery of the rotor with a gap therebetween. When the rotor rotates, the magnetic flux passing through the coil changes, generating an AC voltage, which detects the rotation speed.

[0045] <Configuration of driving control ECU 10A> As shown in FIG. 6, the cruise control ECU 10A according to this embodiment includes a detection unit 11, a vehicle speed control unit 13A, and an estimation unit . Note that components with the same reference numerals as those in the first embodiment have the same functions, and therefore detailed descriptions thereof will be omitted.

[0046] In areas where the uphill gradient of an extremely short road becomes gentle, the vehicle speed control unit 13A executes control to gradually decrease the value of the first-order delay time constant used in the estimation unit 14 described later, depending on the distance between the vehicle detected by the detection unit 11 and the vicinity of the top of the extremely short road.

[0047] The estimation unit 14 filters the sensor outputs of the acceleration sensors 40 provided at the front and rear of the vehicle using a first-order lag time constant to estimate the uphill gradient of the extremely short road. Specifically, when the host vehicle is stopped, the estimation unit 14 sets the road surface gradient value based on sensor information detected by the acceleration sensor 40 in front of and behind the vehicle. Furthermore, while the vehicle is traveling, the estimation unit 14 obtains wheel acceleration by time-differentiating the wheel speeds of the drive wheels detected by each wheel speed sensor 70 from the sensor information at the front and rear of the vehicle, subtracts (corrects) the average value from the sensor information at the front and rear of the vehicle, removes the acceleration component, and then performs filtering using a first-order lag time constant to estimate the road surface gradient value.

[0048] <Processing of the driving control device 1A> The processing of the cruise control device 1A according to this embodiment will be described with reference to FIGS.

[0049] The host vehicle starts traveling with ACC (Adaptive Cruise Control) applied (step S201). Then, the vehicle starts traveling uphill (step S102).

[0050] The vehicle speed control unit 13A determines in the detection unit 11 from the driving environment information acquired by the information acquisition unit 20 whether the vehicle has reached an area where the uphill gradient of an extremely short road, such as an overpass, becomes gentle, i.e., the control start point (step S203). Specifically, the vehicle speed control unit 13A determines in the detection unit 11 whether or not the vicinity of the top of an extremely short road such as an overpass (the recognition point in Figure 8) has been confirmed from the image information of the area ahead of the vehicle acquired by the information acquisition unit 20. Then, when the detection unit 11 determines from the driving environment information acquired by the information acquisition unit 20 that the image information in front of the vehicle does not indicate the vicinity of the top of an extremely short road such as an overpass ("NO" in step S203), the vehicle speed control unit 13A transitions to standby mode.

[0051] On the other hand, when the vehicle speed control unit 13A determines in the detection unit 11 from the driving environment information acquired by the information acquisition unit 20 that the image information in front of the vehicle indicates that the top of an extremely short road such as an overpass has been confirmed ("YES" in step S203), the vehicle speed control unit 13A executes control to reduce the first-order lag filter time constant according to the distance to the top of the extremely short road such as an overpass (step S204). By carrying out such control, as shown in FIG. 8, the current estimated gradient (dotted line in FIG. 8), which had deviated from the actual gradient (solid line in FIG. 8), becomes closer to the actual gradient.

[0052] Next, vehicle speed control unit 13A determines whether a predetermined time has elapsed since the host vehicle reached the top of an extremely short road such as an overpass, that is, whether the host vehicle has reached the control end point (step S205). Here, the "predetermined time" can be, for example, 10 seconds. As an example of the control end point, the point where a downhill slope ends and becomes flat may be detected by a camera, and if the distance to the end point of the downhill slope is within a predetermined range, that point may be set as the control end point. The point where the downhill slope ends and becomes flat may be detected by comparing it with objects that serve as horizontal and vertical references, such as signs or houses around the road. Then, when the vehicle speed control unit 13A determines that the vehicle has not reached the control end point ("NO" in step S205), the vehicle speed control unit 13A transitions to the standby mode.

[0053] On the other hand, when it is determined that the vehicle has reached the control end point ("YES" in step S205), the vehicle speed control unit 13A returns the first-order lag filter time constant to the initial value (step S206).

[0054] Then, when the vehicle speed control unit 13A determines in the detection unit 11 from the image information of the area ahead of the vehicle acquired by the information acquisition unit 20 that the vehicle has finished descending the slope (step S207), it ends the processing while continuing ACC driving (step S208).

[0055] <Actions and Effects> As explained above, the driving control device 1A according to this embodiment further includes an estimation unit 14 that filters the sensor output of the acceleration sensors 40 provided in front of and behind the vehicle using a first-order lag time constant to estimate the uphill gradient of the very short road, and the vehicle speed control unit 13A sequentially decreases the value of the first-order lag time constant in areas where the uphill gradient of the very short road becomes gentler, depending on the distance between the vehicle and the vicinity of the top of the very short road detected by the detection unit 11. In other words, in the area where the uphill gradient of the very short road becomes gentle, the vehicle speed control unit 13A gradually decreases the value of the first-order delay time constant according to the distance between the vehicle detected by the detection unit 11 and the vicinity of the top of the very short road, so that the estimated gradient estimated by the estimation unit 14 approaches the actual gradient.

[0056] <Third embodiment> A driving control device 1B according to this embodiment will be described with reference to FIGS.

[0057] <Configuration of driving control device 1B> As shown in FIG. 9, the driving control device 1B according to this embodiment is configured to include a driving control ECU (Electronic Control Unit) 10B, an information acquisition unit 20, a vehicle speed sensor 30, an acceleration sensor 40, an engine ECU 50, an engine Act 51, a brake control ECU 60, a brake Act 61, and a wheel speed sensor 70. Note that components with the same reference numerals as those in the first and second embodiments have the same functions, and therefore detailed descriptions thereof will be omitted.

[0058] The travel control ECU 10B executes control related to the travel of the vehicle, and suppresses unnecessary acceleration of the host vehicle in areas where the uphill gradient of an extremely short road becomes gentle. In this embodiment, the cruise control ECU 10B detects an area where the upward gradient of an extremely short road, such as an overpass, becomes gentle, based on the traveling environment information acquired by the information acquisition unit 20. Specifically, the cruise control ECU 10B controls the acceleration control unit 12 to clear the integral control component in the area where the uphill gradient of an extremely short road becomes gentle. Specifically, when the difference between the acceleration of the host vehicle and the target acceleration becomes equal to or less than zero, the cruise control ECU 10B controls the acceleration control unit 12 to clear the integral control component. In addition, in this embodiment, in areas where the uphill gradient of an extremely short road becomes gentle, the driving control ECU 10B executes control to gradually decrease the value of the first-order delay time constant used in the estimation unit described later, depending on the distance between the vehicle detected by the detection unit 11 and the vicinity of the top of the extremely short road.

[0059] <Configuration of driving control ECU 10B> As shown in FIG. 10, the cruise control ECU 10B according to this embodiment includes a detection unit 11, an acceleration control unit 12, a vehicle speed control unit 13B, and an estimation unit . Note that components with the same reference numerals as those in the first and second embodiments have the same functions, and therefore detailed descriptions thereof will be omitted.

[0060] Vehicle speed control section 13B controls acceleration control section 12 so as to clear the integral control component in an area where the uphill gradient of an extremely short road becomes gentle. Furthermore, when the difference between the acceleration of the vehicle and the target acceleration becomes zero or less, the vehicle speed control section 13B controls the integral control component in the acceleration control section 12 to be cleared. In areas where the uphill gradient of the extremely short road becomes gentle, the vehicle speed control unit 13B executes control to gradually decrease the value of the first-order delay time constant used in the estimation unit 14 described later, depending on the distance between the vehicle detected by the detection unit 11 and the vicinity of the top of the extremely short road.

[0061] <Processing of the driving control device 1B> The processing of the cruise control device 1B according to this embodiment will be described with reference to FIGS.

[0062] The host vehicle starts traveling with ACC (Adaptive Cruise Control) applied (step S301). Specifically, for example, in (1) of FIG. 12, the cruise control device 1 sets the set vehicle speed (SET vehicle speed) to 50 km / h and causes the host vehicle to start traveling with ACC (Adaptive Cruise Control) applied.

[0063] For example, the vehicle starts traveling uphill in (2) of FIG. 12 (step S302). At this time, the vehicle speed drops to, for example, about 49.5 km / h due to the influence of the uphill gradient. For example, in FIG. 12(2A), the acceleration feedback offset (AFBOffset) starts to increase, but because this timing is slightly delayed compared to the actual gradient, the vehicle speed of the vehicle is affected by the uphill gradient and further decreases, for example, to about 47 km / h. In addition, in (3) of Figure 12, as the acceleration feedback offset value increases, the vehicle speed of the vehicle increases to 49 km / h, which is close to the set vehicle speed (SET vehicle speed), due to the control (acceleration feedback offset control) of the acceleration control unit 12 based on the deviation between the acceleration of the vehicle and the target acceleration. Furthermore, for example, in (3A) of FIG. 12, even if the vehicle speed of the host vehicle exceeds the set vehicle speed, the acceleration feedback offset value increases, and therefore the vehicle speed of the host vehicle increases to approximately 51 km / h due to the control (acceleration feedback offset control) of the acceleration control unit 12 based on the deviation between the acceleration of the host vehicle and the target acceleration. 12(4), the acceleration feedback offset value still increases even if the vehicle speed exceeds the set vehicle speed. In addition, due to a delay in gradient estimation, the vehicle speed of the vehicle increases to about 52 km / h due to the control by acceleration control unit 12 based on the deviation between the acceleration of the vehicle and the target acceleration (acceleration feedback offset control).

[0064] The acceleration control unit 12 determines whether the detection unit 11 has detected an area with a gentle uphill gradient on an extremely short road, such as an overpass, from the driving environment information acquired by the information acquisition unit 20 (step S303). Specifically, the acceleration control unit 12 detects the vicinity of the top of an extremely short road such as an overpass from the image information ahead of the vehicle acquired by the information acquisition unit 20 in the detection unit 11, and determines whether the distance from the current position of the vehicle ((4) in Figure 12) to the vicinity of the top of the extremely short road such as an overpass is a predetermined distance, in other words, whether the current position of the vehicle is the control start point. In addition, the vehicle speed control unit 13B determines in the detection unit 11 from the driving environment information acquired by the information acquisition unit 20 whether the vehicle has reached an area where the uphill gradient of an extremely short road, such as an overpass, becomes gentle, i.e., the control start point. Specifically, the vehicle speed control unit 13B determines in the detection unit 11 from the image information of the area ahead of the vehicle acquired by the information acquisition unit 20 whether the top of an extremely short road such as an overpass has been confirmed.

[0065] Then, when the detection unit 11 determines that it is unable to detect an area with a gentle uphill gradient on an extremely short road such as an overpass from the driving environment information acquired by the information acquisition unit 20 ("NO" in step S303), the acceleration control unit 12 transitions to standby mode.

[0066] On the other hand, if the acceleration control unit 12 determines that the detection unit 11 has detected an area where the uphill gradient of an extremely short road, such as an overpass, becomes gentle from the driving environment information acquired by the information acquisition unit 20 ("YES" in step S303), the vehicle speed control unit 13B executes control to clear the integral term of the acceleration feedback offset (step S304).

[0067] In addition, when the vehicle speed control unit 13B determines in the detection unit 11 from the driving environment information acquired by the information acquisition unit 20 that the image information in front of the vehicle indicates that the vicinity of the top of an extremely short road such as an overpass has been confirmed, the vehicle speed control unit 13B executes control to reduce the first-order lag filter time constant according to the distance to the vicinity of the top of the extremely short road such as an overpass (step S305). These two controls clear the acceleration feedback offset value and reduce the first-order delay filter time constant, so that the vehicle speed decelerates from, for example, about 52 km / h in FIG. 12 (4) to the set vehicle speed of 50 km / h in FIG. 12 (5). In FIG. 12 (5A), the vehicle reaches a gentle gradient area near the top of a slope, which reduces the time constant of the first-order lag filter, and the vehicle speed is maintained at the set speed of 50 km / h.

[0068] After the host vehicle starts climbing, the acceleration control unit 12 sets the target acceleration to 0 [m / s 2 ] is determined (step S306). The acceleration control unit 12 determines whether the target acceleration is 0 [m / s 2 If it is determined that the setting is not "YES" ("NO" in step S306), the process goes to standby mode.

[0069] On the other hand, the acceleration control unit 12 determines whether the target acceleration is 0 [m / s 2 If it is determined that the integral term of the acceleration feedback offset control is 0.0 (YES in step S306), vehicle speed control section 13B executes control to clear the integral term of the acceleration feedback offset control (step S304). In this case, the vehicle speed of the host vehicle decelerates from, for example, 52 km / h in FIG. 12 (4) to 50 km / h in FIG. 12 (5), and the vehicle speed reaches 50.5 km / h due to the influence of the downhill slope in FIG. 12 (6). However, the acceleration feedback offset value becomes a negative value, so that the vehicle speed does not exceed the limit excessively. In (6A) of FIG. 4, the vehicle speed is reduced by the negative acceleration feedback offset value, and the acceleration feedback offset value is also cleared.

[0070] Next, vehicle speed control unit 13B determines whether a predetermined time has elapsed since the host vehicle reached the top of an extremely short road such as an overpass, that is, whether the host vehicle has reached the control end point (step S307). Then, when the vehicle speed control section 13B determines that the vehicle has not reached the control end point ("NO" in step S307), the vehicle speed control section 13B transitions to a standby mode.

[0071] On the other hand, when it is determined that the vehicle has reached the control end point ("YES" in step S307), the vehicle speed control unit 13B returns the first-order lag filter time constant to the initial value (step S308).

[0072] Then, when the vehicle speed control unit 13B determines in the detection unit 11 from the image information of the area ahead of the vehicle acquired by the information acquisition unit 20 that the vehicle has finished descending the slope (step S309), it ends the processing while continuing ACC driving (step S310).

[0073] <Actions and Effects> As explained above, the vehicle speed control unit 13B of the driving control device 1B according to this embodiment controls the integral control component in the acceleration control unit 12 to be clear in the region where the uphill gradient of the extremely short road becomes gentle, or controls the integral control component in the acceleration control unit 12 to be clear when the difference between the acceleration of the vehicle and the target acceleration is equal or the target acceleration is greater than the acceleration of the vehicle, and in addition, in the region where the uphill gradient of the extremely short road becomes gentle, the vehicle speed control unit 13B executes control to gradually decrease the value of the first-order delay time constant used in the estimating unit 14 as the gradient of the extremely short road becomes gentler. In other words, when a predetermined condition is satisfied, the vehicle speed control unit 13B not only performs control to clear the integral control component in the acceleration control unit 12, but also performs control to gradually decrease the value of the first-order delay time constant used in the estimation unit 14. That is, when the speed of the vehicle traveling on an uphill road reaches the control start point, excessive acceleration of the speed of the vehicle near the top of an extremely short road is suppressed by control that clears the integral control component in the acceleration control unit 12 executed by the vehicle speed control unit 13B and control that gradually decreases the value of the first-order delay time constant used in the estimation unit 14. Therefore, when the vehicle travels uphill, safe travel can be achieved without causing unnecessary fear to the occupants.

[0074] The driving control devices 1, 1A, 1B of the present invention can be realized by recording the processing of the driving control ECUs 10, 10A, 10B on a computer-readable recording medium, and having the driving control ECUs 10, 10A, 10B read and execute the program recorded on the recording medium. The computer system here includes hardware such as an OS and peripheral devices.

[0075] Furthermore, if a WWW (World Wide Web) system is used, the "computer system" also includes the homepage provision environment (or display environment). The above program may be transmitted from a computer system that stores the program in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has the function of transmitting information, such as a network (communication network) like the Internet or a communication line (communication line) like a telephone line.

[0076] The program may also be a program for implementing some of the functions described above, or may be a so-called differential file (differential program) that can implement the functions described above in combination with a program already stored in the computer system.

[0077] The above has described in detail an embodiment of the present invention with reference to the drawings, but all driving control devices that can be implemented by a person skilled in the art by making appropriate design modifications based on the driving control devices 1, 1A, and 1B described above as embodiments of the present invention also fall within the technical scope of the present invention as long as they include the gist of the present invention. Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that these modifications and alterations also fall within the technical scope of the present invention. For example, any embodiment in which a person skilled in the art has appropriately added or deleted components or modified the design, or added or omitted steps or modified conditions, is included within the technical scope of the present invention as long as it contains the gist of the present invention.

[0078] Furthermore, other effects and advantages brought about by the aspects described in this embodiment that are clear from the description in this specification or that can be appropriately thought of by a person skilled in the art are naturally understood to be brought about by the present invention. Various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be omitted from all the components shown in the embodiment. Furthermore, components from different embodiments may be combined as appropriate. [Explanation of symbols]

[0079] 1; Driving control device 1A: Driving control device 1B: Driving control device 10. Driving control ECU 10A: Driving control ECU 10B: Driving control ECU 11: Detection unit 12: Acceleration control section 13: Vehicle speed control unit 13A: Vehicle speed control unit 13B: Vehicle speed control unit 14;Estimation part 20; Information acquisition department 30: Vehicle speed sensor 40: Acceleration sensor 50;Engine ECU 51;Engine Act 60;Brake control ECU 61;Brake Act 70: Wheel speed sensor

Claims

1. an information acquisition unit that acquires information about the surrounding driving environment including the area ahead of the host vehicle; a detection unit that detects an area where the upward gradient of an extremely short road, such as an overpass, becomes gentle based on the acquired traveling environment information; a vehicle speed control unit that suppresses unnecessary acceleration / deceleration of the host vehicle that occurs based on an integrated value of a deviation between an acceleration of the host vehicle and a target acceleration in an area where the uphill gradient of the extremely short road becomes gentle; A driving control device comprising:

2. an acceleration control unit that controls the acceleration of the host vehicle by integral control based on an integrated value of a deviation between the acceleration of the host vehicle and a target acceleration; 2. The driving control device according to claim 1, wherein the vehicle speed control unit controls the acceleration control unit to clear the integral control component in an area where the uphill gradient of the extremely short road becomes gentle.

3. 3. The driving control device according to claim 2, wherein the area where the upward gradient becomes gentle is defined according to the distance from the vehicle to the top of the extremely short road, which is acquired by the information acquisition unit.

4. an acceleration control unit that controls the acceleration of the host vehicle by integral control based on an integrated value of a deviation between the acceleration of the host vehicle and a target acceleration; 2. The driving control device according to claim 1, wherein the vehicle speed control unit controls the integral control component in the acceleration control unit to be cleared when a difference between the acceleration of the host vehicle and a target acceleration becomes zero or less.

5. an estimation unit that performs filtering processing on sensor outputs of acceleration sensors provided at the front and rear of the vehicle using a first-order delay time constant to estimate the uphill gradient of the extremely short road; 5. The driving control device according to claim 1, wherein the vehicle speed control unit sequentially decreases the value of the first-order delay time constant in a region where the uphill gradient of the extremely short road becomes gentle, depending on the distance between the vehicle and the top of the extremely short road.

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