Driving control device, vehicle and driving control procedure

Abstract

Driving control device (100), comprising: a road determination unit (110) that determines whether a road on which a vehicle (1) is to travel has a downward slope, and the downward slope has successive curved paths with a first curved path and a second curved path directly adjoining the first curved path; and a driving control unit (120) which, in a case where the road determination unit (110) determines that the road includes the first curved track and the second curved track, causes the vehicle (1), which has been directed to drive in such a way as to maintain a target speed, to decelerate on a curve entry side of the first curved track so that the vehicle (1) is able to traverse the first curved track, and causes the vehicle (1) to accelerate by initiating a coasting maneuver from a curve exit side of the first curved track, so that a speed of the vehicle (1) increases.

Description

Technical area

[0001] The present disclosure relates to a driving control apparatus, a vehicle, and a driving control method. Technical background

[0002] So far, techniques have been developed for controlling cruise control (powered driving) in which a vehicle speed is maintained at a pre-set target speed (see, for example, patent literature (hereinafter abbreviated as PTL) 1).

[0003] DE 10 2015 000 538 A1 relates to a motor vehicle having a navigation device with stored route sections, each of which is assigned a permissible maximum speed, and a cruise control system which is designed to regulate an actual speed of the motor vehicle to a temporary speed derived taking into account the permissible maximum speed and / or a road layout derived from a stored route section by controlling a drive of the motor vehicle (1).

[0004] DE 10 2008 023 135 B4 relates to a method for operating a vehicle in which the topography of a route is provided as topography data. Based on the topography data, the current speed, and a parameter for the vehicle's rolling characteristics, the vehicle's speed profile during rolling operation is predicted for a predetermined, upcoming section of the route.

[0005] DE 10 2012 025 036 A1 relates to a method for operating a driver assistance system of a motor vehicle to assist a driver of the motor vehicle in energy-efficient driving on a route ahead. The current driving speed of the motor vehicle and a location on the route ahead at which the motor vehicle must reach a target speed are determined. Based on the current driving speed, a driving speed profile of the motor vehicle is determined, as it would result if the motor vehicle were coasting.

[0006] DE 10 2011 103 096 A1 relates to a motor vehicle, comprising a driver assistance system with a control device for the automatic longitudinal guidance of the motor vehicle, a navigation system comprising a storage means with route data and route attributes, a position determination system for determining the geographical vehicle position, and one or more actuators provided on the vehicle, which can be controlled directly or indirectly via the control device within the framework of the longitudinal guidance.

[0007] JP 2006-137235 A relates to a cruise control device in which, when the current speed of a vehicle detected by a speed sensor is greater than a suitable speed and the deceleration intention of a driver is detected by a part that detects the driver's intention, an operating part actuates a brake actuator via a brake control part to automatically decelerate the vehicle. Citation listPatent literature

[0008] PTL 1 Japanese Patent Application Laid-Open JP 2006 - 168 509 A Summary of the inventionTechnical problem

[0009] During powered driving, a vehicle drives autonomously, relying on position information, map data, and similar information from the Global Positioning System (GPS). Accordingly, the vehicle is capable of fuel-efficient driving.

[0010] However, a conventional vehicle may consume energy wastefully and may not be able to achieve fuel-efficient driving on a road with successive curves, such as a mountain road, even if the road has a downhill gradient.

[0011] For example, if a vehicle is traveling down two consecutive curved paths with a downward slope, the vehicle decelerates sufficiently to negotiate the first curved path (e.g., to safely negotiate without rolling over). The vehicle then accelerates through powered driving to reach a target speed and then decelerates again to negotiate the second curved path. Thus, even when traveling downhill on consecutive curves, the vehicle accelerates through powered driving and may therefore not be able to achieve fuel-efficient driving.

[0012] The object of the present disclosure is to provide a driving control apparatus, a vehicle and a driving control method capable of realizing fuel-efficient driving even on a road having successive curves and a downward slope. Solution to the problem

[0013] A driving control device according to one aspect of the present invention comprises: a road determining unit that determines whether a road on which a vehicle is to travel has a downward slope, and the downward slope has successive curved paths including a first curved path and a second curved path directly connected to the first curved path;and a driving control unit that, in a case where the road determining unit determines that the road includes the first curved path and the second curved path, causes the vehicle, which has been caused to travel while maintaining a target speed, to decelerate on a curved path entry side of the first curved path so that the vehicle is able to travel through the first curved path, and causes the vehicle to accelerate by starting a coasting run from a curved path exit side of the first curved path so that a speed of the vehicle increases.;

[0014] A vehicle according to one aspect of the present disclosure includes the driving control device described above.

[0015] A travel control method according to one aspect of the present disclosure: determining whether a road on which a vehicle is to travel has a downward slope, and the downward slope includes successive curved paths having a first curved path and a second curved path directly connected to the first curved path; and in a case where it is determined that the road includes the first curved path and the second curved path, causing the vehicle, which has been caused to travel while maintaining a target speed, to decelerate on a curved path entry side of the first curved path so that the vehicle is able to travel through the first curved path, and causing the vehicle to accelerate by starting a coasting run from a curved path exit side of the first curved path so that a speed of the vehicle increases. Advantageous effects of the invention

[0016] According to the present disclosure, fuel-efficient driving can also be realized on a road with consecutive curves and a downhill gradient. Brief description of the drawings Fig. 1 is a block diagram illustrating an example of the configuration of a vehicle including a driving control device according to an embodiment; Fig. 2 is a diagram for describing an example of a cam entry side and a cam exit side; Fig. 3 is a diagram for describing an example of successive curved paths; Fig. 4 is a block diagram showing an example of the configuration of the driving control device; Fig. 5 is a diagram illustrating an example of a driving sequence for describing an example of operation of a driving control unit; and Fig. 6 is a flowchart showing an example of the operation of the driving control device. Description of embodiments

[0017] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. First, the configuration of a vehicle including the driving control device 100 according to this embodiment will be described.

[0018] Fig. 1 is a block diagram illustrating an example of the configuration of vehicle 1 including the driving control device 100 according to this embodiment. Here, the parts related to the driving control device 100 will be illustrated and described.

[0019] The Fig. The vehicle 1 shown in Figure 1 is, for example, a large-capacity vehicle, such as a truck, in which a series four-cylinder diesel engine is installed.

[0020] As in Fig. 1, vehicle 1 comprises, as components of a drive system that makes the vehicle move, engine 3, clutch 4, gearbox (transmission) 5, thrust shaft (propeller shaft) 6, differential device (differential gear) 7, drive shaft (drive shaft) 8 and wheels 9.

[0021] The power of engine 3 is transmitted to the transmission 5 via the clutch 4, and the power transmitted to the transmission 5 is further transmitted to the wheels 9 via the thrust shaft 6, the differential gear 7, and the drive shaft 8. Accordingly, the power of engine 3 is transmitted to the wheels 9, and vehicle 1 moves.

[0022] In addition, vehicle 1 includes the braking device 40 as part of a braking system for stopping the vehicle. The braking device 40 includes the foot brakes 41 which apply resistance to the wheels 9, the retarder 42 which applies resistance to the thrust shaft 6, and an auxiliary brake 43, such as an exhaust brake, which applies a load to the engine 3.

[0023] Furthermore, vehicle 1 includes the autonomous driving device 2 as part of a control system for controlling the travel of vehicle 1. The autonomous driving device 2 is a device that controls the engine 3, clutch 4, transmission 5 and braking device 40 so that the vehicle 1 performs an autonomous travel, and includes a plurality of control devices.

[0024] Specifically, the autonomous driving device 2 includes the engine ECU (engine control unit) 10, the power transmission ECU (power transmission control device) 11, the target traveling speed setting device 13, the increase / decrease setting device 14, the traveling condition determination device 20, the vehicle information determination device 30, and the traveling control device 100. The engine ECU 10, the power transmission control device 11, and the traveling control device 100 are connected to each other via an on-board network and are capable of transmitting / receiving the necessary data or control signals to each other.

[0025] The engine ECU 10 controls the power of engine 3. The transmission ECU 11 controls the connection / disconnection of clutch 4 and gear changes in transmission 5.

[0026] Target vehicle speed setting device 13 sets a target speed of vehicle 1 during powered travel to the travel control device 100. Increase / decrease setting device 14 sets a speed reduction value and an increase value for the speed of vehicle 1 during travel to the travel control device 100. The target speed, the speed reduction value, and the speed increase value are parameters used for the autonomous travel of vehicle 1.

[0027] The target vehicle speed setting device 13 and the increase / decrease value setting device 14 include an information input interface, such as a touchscreen display, which is located, for example, in a dashboard of a driver's seat (not shown) and receives the settings of the aforementioned parameters from a driver. The target speed, the deceleration value, and the acceleration value are referred to as "target information" where appropriate.

[0028] The driving condition detecting device 20 detects the driving conditions indicating the road condition and the current position of vehicle 1, and outputs the driving conditions to the travel control device 100. The driving condition detecting device 20 includes, for example, the current position detecting device 21, which is a receiver of a GPS system, the driving weather detecting device 22, and the environmental sensor 23, which detects the distance to and the difference in vehicle speed from a vehicle around vehicle 1, such as a vehicle traveling in front of or beside vehicle 1.

[0029] The vehicle information acquisition device 30 acquires vehicle information indicating operations performed by the driver and a state of the vehicle 1, and outputs the vehicle information to the driving control device 100. The vehicle information acquisition device 30 includes, for example, an acceleration sensor 31 that detects the degree of accelerator pedal operation, a brake switch 32 that detects whether or not a brake pedal has been depressed, a shift lever 33, a turn signal switch 34, and a vehicle speed sensor 35 that detects the speed of the vehicle 1.

[0030] The driving control device 100 generates a driving plan including powered driving (autonomous driving) and coasting driving based on the above-described target value information, the driving conditions, and the vehicle information. The driving control device 100 controls the individual parts of the vehicle 1 so that the vehicle 1 travels in accordance with the generated driving plan. In this embodiment, the powered driving is autonomous driving in which the speed of the vehicle 1 is maintained within a speed range from a speed higher than a lower limit speed set low relative to a target speed to a speed lower than an upper limit speed set high relative to the target speed.

[0031] Coasting includes engine braking, in which vehicle 1 travels by applying an engine brake using the driven rotation of engine 3 without interrupting a power transmission path between engine 3 and wheels 9, and neutral idling (hereinafter also referred to as "N coasting"), in which vehicle 1 travels with the power transmission path between engine 3 and wheels 9 interrupted. During engine braking and N coasting, the fuel injection of engine 3 is stopped.

[0032] Fig. 2 is a diagram for describing an example of a cam track entry side and a cam track exit side. Fig. Figure 2 illustrates the curved path C1 and the vehicle 1.

[0033] The Fig. Line L1 shown in Figure 2 indicates a "specific position of the curved path C1." The specific position of the curved path C1 may, for example, be a position where a road length in an area on the entrance side of the curved path C1 is equal to (or substantially equal to) a road length in an area on the exit side of the curved path C1.

[0034] The "curved path entry side" is an area from the specific position of the curved path C1 to the entry side of the curved path C1 and includes, for example, an area in front of the curved path C1 in a vehicle travel direction and an area near the entrance of the curved path C1. Fig. For example, the double-sided arrow Ca shown in the figure indicates the entrance side of the curved path. Similarly, the "curved path exit side" is an area from the specific position of the curved path C1 to the exit side of the curved path C1, and includes, for example, an area after the curved path C1 in the direction of travel of the vehicle and an area near the exit of the curved path C1. Fig. For example, the double-sided arrow Cb shown indicates the starting side of the curved path. The specific position of the curved path C1 can be, for example, a clipping point (acceleration starting point) of vehicle 1.

[0035] Fig. Figure 3 is a diagram showing an example of successive curved paths. Fig. Figure 3 illustrates the curved path C11 and the curved path C12, which follows the curved path C11. The curved path C12 has a smaller radius of curvature than the curved path C11. Arrow A1 in Fig. 3 indicates the direction of travel of vehicle 1.

[0036] Fig. Figure 3 shows graph G1, which shows the gradients (high or low) of the curved paths C11 and C12. As shown in graph G1, the curved paths C11 and C12 on which vehicle 1 travels have a downward slope.

[0037] In the example in Fig. 3, the curved paths C11 and C12 have the same downward slopes (the slope of graph G1 is constant). Alternatively, the curved paths C11 and C12 can have different slopes.

[0038] In the example in Fig. 3, the curved path C11 is a right turn, and the curved path C12 is a left turn in the direction of travel of the vehicle. Alternatively, the curved paths C11 and C12 can be curved in the same direction. For example, the first curved path C11 can be a right turn, and the second curved path C12 can be a right turn in the direction of travel of the vehicle.

[0039] Fig. 4 is a block diagram showing an example of the configuration of the driving control device 100. As shown in Fig. 4, the driving control device 100 includes the road determination unit 110 and the driving control unit 120.

[0040] The road determination unit 110 determines whether a road on which vehicle 1 is to travel and which has a downward slope has a first curved path and a second curved path with a smaller radius of curvature than the first curved path.

[0041] For example, the road determination unit 110 determines, based on the map data stored in a memory (not shown) and the current position of vehicle 1, whether a road on which vehicle 1 is to travel is the one shown in Fig. 3 contains the curved paths C11 and C12 or not.

[0042] The travel control unit 120 generates a travel plan including the travels and the N-coasting, and causes vehicle 1 to travel based on the current position of vehicle 1 in accordance with the generated travel plan.

[0043] In a case where the road determining unit 110 determines that the road includes the first curved path and the second curved path, the traveling control unit 120 causes vehicle 1, which has been caused to travel while maintaining a target speed in accordance with the travel plan, to decelerate on the entry side of the curved path so that vehicle 1 is able to travel through the first curved path. Subsequently, the traveling control unit 120 causes the vehicle to accelerate through N-exit from the curved path exit side of the first curved path so that the vehicle is able to travel through the second curved path. In other words, in a case where the road determining unit 110 determines that the road includes the first curved path and the second curved path, the traveling control unit 120 does not control the speed of vehicle 1 to the target speed.The travel control unit 120 causes vehicle 1 traveling at the target speed to be decelerated so that vehicle 1 can travel through the first curved path, and causes vehicle 1 to be accelerated by N-coasting.

[0044] Fig. 5 is a diagram illustrating an example of a schedule for describing an example of operation of the driving control unit 120. The Fig. Waveform W1 shown in Figure 5 indicates changes in the speed of vehicle 1 based on travel control by a travel control unit (hereinafter referred to as travel control unit A) that causes vehicle 1 traveling on a curved path with a downward slope to accelerate to a target speed. Waveform W2 indicates changes in the speed of vehicle 1 based on travel control by the travel control unit 120 according to the present disclosure. For example, assume that vehicle 1 travels on a straight road with a downward slope and enters a first curved path with a downward slope. It is also assumed that vehicle 1 passes through the first curved path and then travels on a second curved path with a downward slope, where the radius of curvature of the second curved path is smaller than that of the first curved path.

[0045] The Fig. The "target speed" shown in Figure 5 indicates the target speed of vehicle 1 moving according to the schedule. The target speed is set by the target speed setting device 13 in accordance with the travel control units A and 120.

[0046] The Fig. The "upper limit speed" shown in Figure 5 indicates the upper limit speed of vehicle 1 traveling according to the schedule. The upper limit speed is calculated based on the following equation 1. Upper limit speed=V+V1

[0047] In Equation 1, V represents the target speed of vehicle 1. In Equation 1, V1 represents the speed gain value. The speed gain value V1 is set by the target vehicle speed setting device 13 to the driving control units A and 120. That is, the driving control units A and 120 calculate an upper limit speed by adding the speed gain value V1 to the target speed V set by the target vehicle speed setting device 13.

[0048] The Fig. The "lower limit speed" shown in Figure 5 indicates the lower limit speed of vehicle 1 traveling according to the schedule. The lower limit speed is calculated based on the following equation 2. Lower limit speed=V−V2

[0049] In Equation 2, V represents the target speed of vehicle 1. In Equation 2, V2 represents the deceleration value. The deceleration value V2 is set by the target vehicle speed setting device 13 to the vehicle control units A and 120. That is, the vehicle control units A and 120 calculate a lower limit speed by subtracting the deceleration value V2 from the target speed V set by the target vehicle speed setting device 13. The speed increase value V1 may be equal to the speed decrease value V2.

[0050] The Fig. The speed Cv1 shown in Figure 5 indicates the speed at which vehicle 1 can travel through the first curved path. The speed Cv2 indicates the speed at which vehicle 1 can travel through the second curved path. The second curved path has a smaller radius of curvature than the first curved path, and the speed Cv2 is lower than the speed Cv1. The speeds Cv1 and Cv2 are calculated by the travel control units A and 120.

[0051] The speed Cv1 is calculated, for example, based on the radius of curvature of the first curved path. The speed Cv2 is calculated, for example, based on the radius of curvature of the second curved path. The speed Cv1 can be calculated based on the radius of curvature of the first curved path, the weight of vehicle 1 (e.g., the sum of the weight of the vehicle and its load), and the gradient of the first curved path. The speed Cv2 can be calculated, for example, based on the radius of curvature of the second curved path, the weight of vehicle 1, and the gradient of the second curved path.

[0052] The driving control performed on vehicle 1 by the driving control unit A is described. On the straight road before the first curved path, the driving control unit A causes vehicle 1 to drive in such a way that the target speed is maintained.

[0053] When vehicle 1 has entered the first curved path, the driving control unit A causes vehicle 1 to decelerate on the entry side of the curved path such that vehicle 1 is able to negotiate the first curved path (e.g., such that vehicle 1 is able to safely negotiate the first curved path without causing an overtaking maneuver or the like). For example, the driving control unit A causes vehicle 1 to decelerate to speed Cv1, as shown in the section corresponding to brake BK1 of waveform W1.

[0054] After vehicle 1 decelerates, the driving control unit A causes vehicle 1 to accelerate to the target speed on the exit side of the first curved path. For example, the driving control unit A causes vehicle 1 to accelerate to the target speed, as shown in the section corresponding to acceleration AC1 of waveform W1.

[0055] After vehicle 1 accelerates to the target speed, the driving control unit A maintains the speed at the target speed until vehicle 1 enters the second curved path. For example, the driving control unit A maintains the speed of vehicle 1 at the target speed, as shown in the part corresponding to the constant speed S1 of the waveform W1.

[0056] When vehicle 1 enters the second curved path, the driving control unit A causes vehicle 1 to be decelerated on the entry side of the curved path so that vehicle 1 can negotiate the second curved path (e.g., so that vehicle 1 can safely negotiate the second curved path without causing an impact or the like). For example, the driving control unit A causes vehicle 1 to be decelerated to speed Cv2, as shown in the section corresponding to brake BK2 of waveform W1.

[0057] After vehicle 1 decelerates, the driving control unit A causes vehicle 1 to accelerate to the target speed by driving it on the exit side of the second curved path. In this way, the driving control unit A controls the travel of vehicle 1 on the first and second curved paths.

[0058] After decelerating on the first curved path, the driving control unit A causes vehicle 1 to accelerate to the target speed by traveling, even if the road has a downward slope (see the part corresponding to acceleration AC1 of waveform W1). Thus, vehicle 1 consumes energy (e.g., fuel or the like) due to the acceleration caused by the powered traveling. In particular, although the speed Cv2 at which vehicle 1 can travel through the second curved path is lower than the speed Cv1 at which vehicle 1 can travel through the first curved path, the driving control unit A causes vehicle 1, which has been decelerating to speed Cv1, to accelerate to the target speed by the powered traveling and then decelerate to speed Cv2.

[0059] In contrast, according to the present disclosure, the travel control unit 120 causes the vehicle 1 to accelerate by N-exit from the curve exit side of the first curve, as described. Accordingly, the vehicle 1 prevents energy consumption of acceleration due to powered travel.

[0060] The driving control unit 120 is described below. On the straight road before the first curved path, the driving control unit 120 causes vehicle 1 to drive so as to maintain the target speed.

[0061] When vehicle 1 has entered the first curved path, the travel control unit 120 causes vehicle 1 to be decelerated on the entry side of the curved path so that vehicle 1 is able to negotiate the first curved path. For example, the travel control unit 120 causes vehicle 1 to be decelerated to speed Cv1, as shown in the section corresponding to brake BK11 of waveform W2.

[0062] After vehicle 1 decelerates, the travel control unit 120 causes vehicle 1 to travel in the N-run on the exit side of the first curved path. Since the first curved path and the second curved path have a downward slope, vehicle 1 accelerates. For example, the travel control unit 120 causes vehicle 1 to accelerate through the N-run, as shown in the part corresponding to the downward slope DH1 of the waveform W2.

[0063] When vehicle 1 has entered the second curved path, the travel control unit 120 causes vehicle 1 to decelerate on the entry side of the curved path so that vehicle 1 can traverse the second curved path. For example, if the speed of vehicle 1 is higher than the speed Cv2 at which vehicle 1 can traverse the second curved path, the travel control unit 120 causes vehicle 1 to decelerate to the speed Cv2, as shown in the portion corresponding to brake BK12 of waveform W2.

[0064] After vehicle 1 decelerates, the travel control unit 120 causes vehicle 1 to accelerate to the target speed by coasting along the exit side of the second curved path. In this way, the travel control unit 120 controls the travel of vehicle 1 along the first curved path and the second curved path.

[0065] As described above, the travel control unit 120 causes vehicle 1 to decelerate on the entry side of the first curved path and then coast on the exit side of the first curved path N (see the section corresponding to the downward slope DH1 of the waveform W2). In this way, vehicle 1 does not perform acceleration based on the traveled speed, thus reducing energy consumption.

[0066] The speed of vehicle 1 may exceed the upper limit speed depending on the downward gradient of the first and second curved paths. For example, in a case where the downward gradients are steep, the speed of vehicle 1 may exceed the upper limit speed. In this case, the driving control unit 120 causes vehicle 1 to decelerate so that the speed of vehicle 1 does not exceed the upper limit speed.

[0067] The speed of vehicle 1 may not reach the speed Cv2 depending on the downward gradients of the first and second curved paths. For example, in a case where the downward gradients are moderate, the speed of vehicle 1 may not reach the speed Cv2. In this case, the travel control unit 120 causes vehicle 1 to accelerate to a speed Cv2 above the speed Cv2 through the powered travel, and then vehicle 1 travels in the N-coil.

[0068] Fig. 5 also illustrates the vehicle speed waveform W3 in a case where the first curved path and the second curved path have an upward slope. In the case of an upward slope, the travel control unit 120 controls the travel of vehicle 1 so that the speed of vehicle 1 becomes the speed Cv2 at constant acceleration.

[0069] In the example in Fig. 5, the speeds Cv1 and Cv2 are between the upper limit speed and the lower limit speed, but in some cases may be below the lower limit speed.

[0070] Fig. 6 is a flowchart showing an example of the operation of the travel control device 100. The travel control device 100 performs the process of Fig. 6 repeatedly, e.g. in a given cycle.

[0071] The road determination unit 110 determines whether or not a road on which vehicle 1 is to travel and which has a downward slope includes a first cured path and a second curved path having a smaller radius of curvature than the first curved path (step S11).

[0072] In a case where the road determination unit 110 determines in step S11 that the road on which vehicle 1 is to travel, which has a downward slope, includes the first curved path and the second curved path with a smaller radius of curvature than the first curved path ("Yes" in S11), the travel control unit 120 causes vehicle 1, with vehicle 1 caused to travel to maintain a target speed, to decelerate on the entry side of the curved path so that vehicle 1 travels the first curved path. Subsequently, the travel control unit 120 causes vehicle 1 to accelerate by N-runout from the curved path exit side of the first curved path (step S12).

[0073] On the other hand, in a case where the road determining unit 110 determines in step S11 that the road on which vehicle 1 is to travel and which has a downward slope does not include the first curved path or the second curved path having a smaller radius of curvature than the first curved path ("No" in S11), the process of the flowchart ends.

[0074] As described above, the traveling control device 100 includes the road determining unit 110 that determines whether or not a road on which the vehicle 1 is to travel and which has a downward slope includes a first curved path and a second curved path; and the traveling control unit 120 that, in a case where the road determining unit 110 determines that the road includes the first curved path and the second curved path, causes the vehicle 1, which has been caused to travel to maintain a target speed, to decelerate on a curved path entry side of the first curved path so that the vehicle 1 is able to travel through the first curved path, and causes the vehicle 1 to travel in run-out from a curved path exit side of the first curved path.

[0075] According to the travel control device 100 having such a configuration, vehicle 1 accelerates by using the N-exit to travel through the second curved path, and is thus able to avoid wasteful energy consumption and realize fuel-efficient travel.

[0076] The first curved path can have a curved path entrance that runs horizontally or slopes upwards. This means that it is sufficient for the first curved path to have a downward slope on the exit side of the curved path. In a case where the first curved path has a slope on the exit side of the curved path, vehicle 1 is capable of accelerating by coasting to N.

[0077] A straight road several meters long may lie between the first and second curved paths. The exit side of the first curved path or the second curved path may have an incline or a flat road (e.g., a moderate incline or a flat road several meters long) that does not require acceleration by driving the vehicle.

[0078] The above-described embodiment is merely an example of a concrete implementation for carrying out the present disclosure, and the technical scope of the present disclosure should not be interpreted as being limited thereby. That is, the present disclosure can be implemented in various forms without departing from the gist or main features of the present disclosure.

[0079] This application is based on Japanese Patent Application No. 2017-198766 filed on October 12, 2017, which is incorporated herein by reference in its entirety. Industrial applicability

[0080] The present disclosure is useful as a travel control device, a vehicle, and a travel control method capable of realizing fuel-efficient travel of a vehicle. LIST OF INFLAMMATIONS 1 vehicle 2 Autonomous driving device 3 Engine 4 Clutch 5 gearboxes 6 thrust wave 7 Differential device 8 Drive shaft 9 wheels 10 Engine ECU 11 Powertrain ECU 13 Target driving speed setting device 14 Raise / lower adjustment device 20 Device for determining driving conditions 21 Device for determining the current position 22 Device for determining the weather 23 Environmental sensor 30 Device for determining vehicle information 31 Accelerometer 32 brake switches 33 gear levers 34 Turn signal switch 35 Vehicle speed sensor 40 Braking device 41 Foot brake 42 retarders 43 Auxiliary brake 100 driving control device 110 Street Determination Unit 120 Driving control unit

Claims

[1] Driving control device (100), comprising: a road determination unit (110) which determines whether a road on which a vehicle (1) is to travel has a downward slope, and the downward slope has successive curved paths with a first curved path and a second curved path directly connected to the first curved path; and a driving control unit (120) which, in a case where the road determination unit (110) determines that the road includes the first curved path and the second curved path, causes the vehicle (1) which has been caused to travel so as to maintain a target speed to decelerate on a curved path entry side of the first curved path so that the vehicle (1) is able to travel through the first curved path, and causes the vehicle (1) to accelerate by starting a coasting run from a curved path exit side of the first curved path so that a speed of the vehicle (1) increases. [2] The travel control device (100) according to claim 1, wherein the second curved path has a smaller radius of curvature than the first curved path. [3] The travel control device (100) according to claim 1, wherein in a case where the vehicle (1) on a curved path entry side of the second curved path has a speed higher than a speed at which the vehicle (1) can travel through the second curved path, the travel control unit (120) causes the vehicle (1) to decelerate on the curved path entry side of the second curved path. [4] The travel control device (100) according to claim 1, wherein, in a case where the vehicle (1) on a curved path entry side of the second curved path has a speed that is less than or equal to a speed at which the vehicle (1) is capable of traveling through the second curved path, the travel control unit (120) causes the vehicle (1) to be accelerated by powered travel from the curved path exit side of the first curved path, and thereafter causes the vehicle (1) to start the coasting travel immediately after completion of the acceleration by the powered travel on the curved path exit side of the first curved path. [5] Vehicle (1) comprising the driving control device (100) according to claim 1. [6] A driving control procedure comprising: - determining whether a road on which a vehicle (1) is to travel has a downward slope, and the downward slope has successive curved paths with a first curved path and a second curved path that directly adjoins the first curved path; and in a case where it is determined that the road includes the first curved path and the second curved path, causing the vehicle (1), which has been caused to travel so as to maintain a target speed, to decelerate on a curved path entry side of the first curved path so that the vehicle (1) is able to travel through the first curved path, and causing the vehicle (1) to accelerate by starting a coasting run from a curved path exit side of the first curved path so that a speed of the vehicle (1) increases.

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