Vehicle driving control device, driving control method, and driving control program

Abstract

To provide a vehicular travel control device capable of using for travel control by predicting generatable energy in a vehicle that includes a constant recovery amount of regenerative energy.SOLUTION: A travel control device is provided, mounted to a vehicle that has, as power sources, a motor and an internal combustion engine, the travel control device comprises: a first obtaining portion obtaining a target point of the vehicle; a second obtaining portion obtaining a past travel history from a start point to a destination point; a third obtaining portion obtaining a target electricity storage rate being the electricity storage rate of a battery incorporated in the vehicle; an estimation portion estimating anticipated amount of generated energy being energy enabling electric power generation in a vehicle by the arrival of the vehicle at a target point based on travel history; a setting portion setting, on the basis of the predicted amount of generated energy and the target electricity storage rate, a first section in which only the motor is driven for the travel, and a second section in which at least the engine is driven for the travel; and a control portion controlling the travel of the vehicle on the basis of the first section and second section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a cruise control device mounted on a vehicle. [Background technology]

[0002] In a hybrid vehicle equipped with an electric motor and an internal combustion engine, fuel efficiency can be improved by driving control that efficiently uses the electric motor and the internal combustion engine.

[0003] Patent Document 1 discloses a vehicle driving support device that notifies the driver of a braking start point where regenerative braking operation must be started, based on the vehicle's position and map information of points where stopping or deceleration is required, such as railroad crossings and curves. This vehicle driving support device encourages the driver to apply regenerative braking at a deceleration rate that allows efficient recovery of regenerative energy, thereby increasing the amount of regenerative energy recovered. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4702086 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 can predict the points where regenerative energy can be recovered, but cannot quantitatively predict the amount of regenerative energy that will be recovered. Therefore, if the amount of regenerative energy that will be recovered can be predicted quantitatively and early, it may be possible to effectively estimate the energy that can be generated in a vehicle, including this regenerative energy, and this may be used for suitable driving control.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a vehicle driving control device and the like that can predict the energy that can be generated in a vehicle, including a quantitative amount of regenerative energy recovered, and use the predicted energy for driving control. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the disclosed technology is a driving control device mounted on a vehicle having an electric motor and an internal combustion engine as power sources, the driving control device comprising: a first acquisition unit that acquires a destination point of the vehicle; a second acquisition unit that acquires past driving history from a starting point to the destination point; a third acquisition unit that acquires a target storage rate which is the storage rate of a battery mounted on a target vehicle at the time when the vehicle arrives at the destination point; an estimation unit that estimates an expected amount of generated energy, which is energy that can be generated in the vehicle until it arrives at the destination point, based on the driving history; a setting unit that sets a first section in which only the electric motor is driven for driving and a second section in which at least the internal combustion engine is driven for driving, based on the expected amount of generated energy and the target storage rate; and a control unit that controls the driving of the vehicle based on the first section and the second section. Effect of the Invention

[0008] According to the vehicle driving control device disclosed herein, a predicted amount of energy that can be generated in the vehicle is estimated using a driving history based on past vehicle driving, and it is possible to realize suitable driving control that takes into account the target storage rate of the battery based on the estimated predicted amount of energy. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a functional block diagram of a driving control device according to an embodiment of the present disclosure and its peripheral components; [Figure 2A] 1 is a flowchart of an example of a driving control process executed by a driving control device. [Figure 2B] 1 is a flowchart of an example of a driving control process executed by a driving control device. [Figure 3A]1 is a flowchart of an example of a driving scenario generation process executed by a driving control device. [Figure 3B] 1 is a flowchart of an example of a driving scenario generation process executed by a driving control device. [Figure 4] 1 is a flowchart of an example of a threshold correction process executed by a driving control device. [Diagram 5] FIG. 13 is a diagram showing an example of a running power profile. [Figure 6] A diagram showing the regenerative energy region in the driving power profile. [Figure 7] A diagram showing an example of a speed profile [Figure 8] A diagram showing the region where power generation is possible in the speed profile. [Figure 9] A diagram showing an example of changes in the battery charge rate (no target charge rate) [Figure 10] A diagram showing an example of changes in the battery charge rate (with target charge rate) [Figure 11] A diagram showing an example of a method for determining a threshold (limitation based on an upper limit of tolerance) [Figure 12] A diagram showing an example of a method for determining a threshold (limitation based on the lower allowable limit) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The driving control device according to this embodiment uses a driving power profile that shows a time series of changes in driving power generated by the power source during driving from the starting point to the destination point, and a speed profile that shows a time series of changes in the vehicle speed, to quantitatively estimate the energy that can be generated in the vehicle at an early stage. This makes it possible to utilize the estimation results to perform suitable driving control that takes into account the target charge rate of the battery. Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] [Embodiment] <Configuration> FIG. 1 is a diagram showing functional blocks of a driving control device 10 and its peripheral parts according to an embodiment of the present disclosure. The driving control device 10 is mounted on a vehicle. As illustrated in FIG. 1, in addition to the driving control device 10, the vehicle is equipped with each of the following components: an internal combustion engine ECU 20, an internal combustion engine 21, a transmission 22, an electric motor ECU 30, an electric motor 31, a battery ECU 40, a battery 41, an EPSECU 50, an EPS device 51, a brake ECU 60, a brake device 61, a driving control ECU 70, a driving assistance ECU 80, an automatic driving ECU 90, a manager ECU 100, a memory unit 110, and a communication unit 120. The driving control device 10 is communicatively connected to these components via an in-vehicle network 200 such as a controller area network (CAN) or Ethernet (registered trademark).

[0012] In addition to the configuration described above, the vehicle may be equipped with a variety of devices, such as an accelerator pedal sensor, a brake pedal sensor, a camera, an obstacle sensor, a vehicle speed sensor, a yaw rate sensor, a GPS sensor, and various other sensors, as well as a navigation system, but these are not shown in the present disclosure.

[0013] The internal combustion engine 21 and the electric motor 31 are an actuator (ACT) that serves as a power source for driving the vehicle. The electric motor 31 also functions as a generator that generates electricity through regenerative braking when the vehicle is decelerating or traveling downhill, and as a braking device that generates braking force.

[0014] The internal combustion engine ECU 20 is an electronic control unit (ECU: Electric Control Unit) that controls the internal combustion engine 21 and the transmission 22, which changes the rotation speed between input and output, to generate driving torque and braking torque by engine braking.

[0015] The electric motor ECU 30 is an electronic control unit that controls the electric motor 31 to generate a driving torque and to generate a braking torque by regenerative braking.

[0016] The battery 41 is a secondary battery (such as a lithium ion battery, a nickel metal hydride battery, or a lead storage battery) configured to be chargeable and dischargeable, which can supply electric power to the electric motor 31 and other devices by discharging, and can be charged with electric power (recovered energy) obtained by regenerative braking of the electric motor 31 or electric power (generated energy) obtained by powering operation using the internal combustion engine 21. The battery ECU 40 is an electronic control unit that controls the charging and discharging of electric power from the battery 41.

[0017] The EPS (electric power steering) device 51 is an actuator that performs steering to change the rudder angle of the wheels to change the traveling direction of the vehicle. The EPSECU 50 is an electronic control unit that controls the EPS device 51.

[0018] The brake device (foot brake device) 61 is an actuator that generates a braking force by frictional force against a member that rotates together with the wheel. The brake ECU 60 is an electronic control unit that controls the brake device 61.

[0019] The driving control ECU 70 is an electronic control unit that controls the internal combustion engine ECU 20 and the electric motor ECU 30 according to a driving mode, which will be described later.

[0020] The driving assistance ECU 80 is an electronic control unit that executes various functions to assist driving of the vehicle, such as collision avoidance (PCS), adaptive cruise control (ACC), lane keeping (LKA), lane departure warning (LDW), etc. This driving assistance ECU 80 outputs instructions to control the motion of the vehicle, such as acceleration / deceleration and steering angle, based on vehicle information acquired from various sensors, etc. The functions and number of the driving assistance ECU 80 are not limited.

[0021] The autonomous driving ECU 90 is an electronic control unit that executes the autonomous driving function. Based on vehicle information acquired from various sensors, the autonomous driving ECU 90 outputs instructions to control the motion of the vehicle, such as acceleration / deceleration and steering angle, in order to execute the autonomous driving function.

[0022] The manager ECU 100 is an electronic control unit that issues instructions to the EPSECU 50, the brake ECU 60, the cruise control ECU 70, etc. (hereinafter, these ECUs are collectively referred to as "actuator ECUs") based on instructions from the driving assistance ECU 80, the automatic driving ECU 90, etc. For example, the manager ECU 100 issues acceleration instructions to the cruise control ECU 70, steering instructions to the EPSECU 50, and deceleration instructions to the cruise control ECU 70 and the brake ECU 60.

[0023] When the manager ECU 100 receives instructions from a plurality of driving assistance ECUs 80 and the like, it performs a process called arbitration, which determines which instruction to follow to control the vehicle, based on a predetermined rule, and issues instructions to the actuator ECU based on the result of the arbitration. The details of the driving operations manually performed by the driver or the like on the steering wheel, brake pedal, accelerator pedal, and the like may be acquired by the manager ECU 100 and may be subject to arbitration processing by the manager ECU 100, or may be acquired by the actuator ECU, which may individually arbitrate between the manual driving operations by the driver and the instructions from the manager ECU 100.

[0024] The storage unit 110 stores a driving history of the vehicle. One of the driving histories is a history of when the vehicle was driven in the past, and is information on the driving power generated in the power source (the internal combustion engine 21 and the electric motor 31) at each time point during the period when the vehicle was driven. The driving power is composed of the driving power of the internal combustion engine 21, the driving power of the electric motor 31, and the absorbed power of the electric motor 31. One of the driving histories is information on the speed of the vehicle (vehicle speed) at each time point during the period when the vehicle was driven in the past. This driving history can be generated by periodically storing the driving power and the vehicle speed derived and acquired based on various sensors provided in the vehicle in the storage unit 110 while the power supply system (not shown) of the vehicle is in an on state. The storage unit 110 may be provided as a part of a car navigation system (not shown) mounted on the vehicle, for example.

[0025] The communication unit 120 is capable of wireless communication with a server outside the vehicle (not shown) or with other vehicles, and can receive driving history other than that of the driver that is obtained based on the driving results of other vehicles.

[0026] The driving control device 10 is an electronic control unit (ECU) that controls the driving of a vehicle. The driving control device 10 includes an acquisition unit 11, an estimation unit 12, a setting unit 13, a control unit 14, and a derivation unit 15.

[0027] The acquisition unit 11 acquires information on the destination point of the vehicle, the driving history from the starting point to the destination point, and the target charge rate of the battery 41 at the time of arrival at the destination point (first acquisition unit, second acquisition unit, third acquisition unit). The estimation unit 12 estimates an expected amount of generated energy, which is energy that can be generated in the vehicle, based on each piece of information acquired by the acquisition unit 11. The setting unit 13 sets a section in which the electric motor 31 is used for driving and a section in which the internal combustion engine 21 is used for driving, based on the expected amount of generated energy estimated by the estimation unit 12 and the target charge rate. The control unit 14 controls the driving of the vehicle based on the section set by the setting unit 13. The derivation unit 15 derives the deviation between the driving power based on the driving history and the driving power based on the actual driving.

[0028] Each of the above-mentioned ECUs is typically configured by a computer having a memory, a processor, and an interface. The processor of each ECU realizes each function by, for example, reading and executing a program stored in a non-transitory memory. These ECUs are connected to each other by communication lines, and can operate cooperatively by appropriately communicating with each other.

[0029] The above-described configurations of the devices mounted on the vehicle and the configuration of the driving control device 10 are merely examples, and may be added, replaced, modified, or omitted as appropriate. Furthermore, the functions of each device may be implemented by being integrated into one device or distributed among multiple devices as appropriate.

[0030] For example, the driving control device 10 may be provided as an independent ECU, or may be provided as part of a manager ECU 100 or a driving control ECU 70, or the functions of the driving control device 10 may be distributed to the manager ECU 100 or the driving control ECU 70, etc.

[0031] Also, for example, the cruise control device 10, the cruise control ECU 70, the driving assistance ECU 80, the automatic driving ECU 90, and the manager ECU 100 may be provided as one ECU. Also, for example, the automatic driving ECU 90 does not have to be provided in the vehicle.

[0032] <Control / Processing> An example of the control and processing executed by the cruise control device 10 according to this embodiment will be described in detail below with further reference to FIGS. 2A, 2B, 3A, 3B, and 4. FIG.

[0033] 2A and 2B are flowcharts showing an example of driving control executed by the driving control device 10. The process of FIG. 2A and the process of FIG. 2B are connected by connectors V, W, X, and Y. This driving control is started, for example, when a driver or the like turns on the power supply system of the vehicle to start a trip, and is executed until the trip is ended by turning off the power supply system of the vehicle.

[0034] (Step S201) The control unit 14 judges whether or not it is the initial setting time when the control of the driving mode based on the driving scenario has not yet started. If it is the initial setting time (S201, Yes), the process proceeds to step S202, and if it is not the initial setting time (S201, No), the process proceeds to step S213.

[0035] (Step S202) The acquisition unit 11 acquires a destination point. The destination point is given by, for example, latitude / longitude information. This destination point may be an end point where the vehicle ends its trip, or an arbitrary intermediate point set on the route to the end point. The acquisition unit 11 may acquire the destination point through manual input by the driver of the vehicle, or through automatic input by remote control from a navigation system mounted on the vehicle or a management center outside the vehicle. The destination point may be automatically acquired based on the current position, date, time, day of the week, etc. before the start of the trip, or based on the traveling direction of the vehicle after the start of the trip. When the destination point is acquired, the process proceeds to step S203.

[0036] (Step S203) The acquisition unit 11 acquires a running power profile. The running power profile is power information that indicates, in a time series, changes in running power occurring in the power source (the internal combustion engine 21 and the electric motor 31) at each point in time that are predicted during the vehicle's travel from the starting point (current point) to the destination point. FIG. 5 shows an example of a running power profile. In FIG. 5, the horizontal axis indicates the elapsed time from the start of travel, and the vertical axis indicates the running power. The running power profile acquired by the acquisition unit 11 is generated (or extracted) based on, for example, information stored in the storage unit 110, that is, based on the past running history of the same route from the starting point to the destination point.

[0037] A simple example of generation will be described. For example, in the case of a commuter route in which the starting point to the destination point is traveled at approximately the same time and route, it is considered that the change pattern of the traveling power generated in the power source will be approximately the same in the multiple past travel histories stored corresponding to this commuter route. In this case, the traveling power profile may be generated based on any one of the multiple past histories. Furthermore, in the case where the travel history is assigned attributes such as the day of the week and the time of the travel, the traveling power profile may be generated based on the travel history that has a large number of attributes that match the current travel. In addition, in the case where a navigation system mounted on a vehicle creates a travel route from the starting point to the destination point, the traveling power profile may be generated based on the travel history that has a high similarity to this travel route.

[0038] In addition, when there are multiple driving histories that are candidates for the running power profile, for example, any one of them may be used as the running power profile, or the multiple driving histories may be averaged and used as the running power profile. In addition, when the running history is vehicle information (such as vehicle speed) other than power information that indicates the change in running power that occurred in the power source during running in a time series, the running power profile may be generated based on the vehicle information. The method of generating the running power profile is not limited, and the above-mentioned methods may be combined as appropriate. When the running power profile is acquired, the process proceeds to step S204.

[0039] (Step S204) The acquisition unit 11 acquires a speed profile. A speed profile is information that indicates, in time series, the vehicle's speed at each point in time that is predicted when the vehicle travels from the starting point (current point) to the destination point. An example of a speed profile is shown in Fig. 7. In Fig. 7, the horizontal axis indicates the elapsed time from the start of travel, and the vertical axis indicates the vehicle's speed.

[0040] The speed profile acquired by the acquisition unit 11 is generated (or extracted) based on, for example, information stored in the storage unit 110, that is, a past driving history of the same route from the starting point to the destination point. In a simple example, if the driving pattern of the driver (vehicle) is only a pattern of driving the same route at the same time on weekdays for commuting, the pattern of the change in speed over time included in the driving history is considered to be approximately the same. In such a case, the acquisition unit 11 may create a speed profile based on any of the past driving histories. In addition, the storage unit 110 may classify and store attributes such as the day of the week and time period when the driving was performed in association with the driving history, and the acquisition unit 11 may create a speed profile based on the driving history that has a large number of matches with the attributes such as the day of the week and time period of the current driving. When the speed profile is acquired, the process proceeds to step S205.

[0041] (Step S205) The estimation unit 12 estimates regenerative energy E_est, which is electric energy obtained by regenerative braking of the electric motor 31 while the vehicle is traveling from the starting point to the destination point. The estimation of the regenerative energy E_est is performed based on the traveling power profile. Specifically, a period in which the traveling power is a negative value (less than 0) in the traveling power profile is a period during which it is expected that the regenerative energy can be recovered (recovery period), and the time integral value of the magnitude of the traveling power in this recovery period, that is, the area of ​​the region shown by hatching in FIG. 6, is calculated as the estimated regenerative energy E_est. When estimating the regenerative energy E_est, the estimated value may be corrected taking into account variable factors such as an increase in vehicle weight due to loading luggage, bad weather, etc. Once the regenerative energy E_est is estimated, the process proceeds to step S206.

[0042] It is possible that the running power profile stored in the storage unit 110 as the above-mentioned past running history is approximate data rather than actual data due to restrictions on the memory capacity of the storage unit 110. In such a case, in order to improve the estimation accuracy of the regenerative energy E_est, an integrated value of the negative running power may be stored as a running history separately from the running power profile.

[0043] (Step S206) The estimation unit 12 estimates generated energy E_gen, which is electric energy obtained by highly efficient power generation during high-speed vehicle travel from the starting point to the destination point. The estimation of the generated energy E_gen is performed based on the speed profile. Specifically, a period of high-speed travel in which the vehicle speed is equal to or higher than a predetermined speed (e.g., 100 km / h) in the speed profile is a period (power generation period) during which the efficiency of the internal combustion engine 21 is expected to be high, and the amount of power that can be generated during this power generation period, i.e., the period shown by hatching in FIG. 8, is calculated as the estimated generated energy E_gen. When estimating the generated energy E_gen, the estimated value may be corrected taking into account variable factors such as an increase in vehicle weight due to loading luggage, bad weather, etc. Once the generated energy E_gen is estimated, the process proceeds to step S207.

[0044] (Step S207) The setting unit 13 initializes the required power generation energy E_req by setting it to zero "0". This required power generation energy E_req is a variable that indicates how much electrical energy (amount of power) should be acquired by performing forced power generation when the vehicle is traveling at high speed, and is determined in the process of generating a driving scenario, which will be described later. When the required power generation energy E_req is initialized to zero, the process proceeds to step S208.

[0045] (Step S208) The acquisition unit 11 acquires a target power storage rate SOC_tgt. The target power storage rate SOC_tgt is a power storage rate (SOC: State Of Charge) of the battery 41 that is a target at the time when the vehicle arrives at the destination point, and can be a power storage rate of the battery 41 desired by the driver or the system of the vehicle. The acquisition unit 11 may acquire the target power storage rate SOC_tgt through manual input by the driver of the vehicle or the like, or may acquire the target power storage rate SOC_tgt through automatic input by a navigation system mounted on the vehicle or remote operation from a management center outside the vehicle.

[0046] For example, if the destination is a home that has charging facilities, the battery 41 can be charged after returning home, so the target power storage rate SOC_tgt may be set lower than the standard value. Also, if there is a plan to use a lot of power at the destination (such as at home), the target power storage rate SOC_tgt may be set higher than the standard value. Once the target power storage rate SOC_tgt is acquired, the process proceeds to step S209.

[0047] (Step S209) The acquisition unit 11 acquires the initial charge rate SOC_stt. The initial charge rate SOC_stt is the charge rate of the battery 41 at the time when a driving scenario is to be generated. If it is determined in step S201 that the initial setting is being performed, the initial charge rate SOC_stt is the charge rate of the battery 41 at the start of traveling when a driving scenario is generated for the first time, and if it is determined in step S201 that the initial setting is not being performed, the initial charge rate SOC_stt is the charge rate of the battery 41 during traveling (midway) when a driving scenario is generated again. The acquisition unit 11 can acquire the initial charge rate SOC_stt of the battery 41 from the battery ECU 40 or the like. When the initial charge rate SOC_stt is acquired, the process proceeds to step S210.

[0048] (Step S210) The setting unit 13 performs a process of generating a driving scenario (driving scenario generation process). A driving scenario is information that sets, in a time series, threshold values ​​for dividing a route from a current point to a destination point into a section where the vehicle runs using only the electric motor 31 (hereinafter referred to as a "first section") and a section where the vehicle runs using at least the internal combustion engine 21 (hereinafter referred to as a "second section"). This driving scenario generation process will be described later. Once the driving scenario is generated, the process proceeds to step S211.

[0049] (Step S211) The control unit 14 reads out the driving scenario generated by the driving scenario generation process. After the driving scenario is read out, the process proceeds to step S212.

[0050] (Step S212) The control unit 14 controls the vehicle's driving mode based on the driving scenario. More specifically, the control unit 14 determines a section where the magnitude of the driving power is equal to or less than the threshold of the driving scenario as a first section, and determines a section where the magnitude of the driving power exceeds the threshold of the driving scenario as a second section. In the first section, the control unit 14 selects the "electric motor mode" for driving only the electric motor 31 as the driving mode, and notifies the driving control ECU 70. In response to this notification, the driving control ECU 70 causes the electric motor ECU 30 to control driving by the electric motor 31. In addition, in the second section, the control unit 14 selects, for example, the "internal combustion engine mode" for driving only the internal combustion engine 21 as the driving mode, and notifies the driving control ECU 70. In response to this notification, the driving control ECU 70 causes the internal combustion engine ECU 20 to control driving by the internal combustion engine 21.

[0051] In the electric motor mode, regenerative braking is performed by the electric motor 31, and the kinetic energy of the vehicle is recovered as electric power. When a certain level of deceleration is required because the driver depresses the brake pedal hard or the driving assistance ECU 80 issues a high-priority command for rapid deceleration to avoid a collision, the manager ECU 100 and the brake ECU 60 control the brake device 61 to generate a sufficient braking force.

[0052] In the above embodiment, an example has been described in which the driving scenario sets the driving mode for the second section to the internal combustion engine mode in which only the internal combustion engine 21 is driven for driving. However, since the charge rate of the battery 41 is controlled to be substantially constant in hybrid driving, the "hybrid mode" in which at least the internal combustion engine 21 is driven for driving may be selected as the driving mode for the second section instead of the internal combustion engine mode.

[0053] (Step S213) The derivation unit 15 derives an absolute difference E_d(t) of the power integrated value from the starting point (t=0) to the current point (t=T). The absolute difference E_d(t) of the power integrated value is a numerical value indicating the absolute difference between an integrated value ΣP_present(t) of the magnitude of the running power obtained by the actual running of the vehicle and an integrated value ΣP_past(t) of the magnitude of the running power calculated based on the running power profile, as shown in the following formula [1]. This absolute difference E_d(t) of the power integrated value is derived at a constant period after the vehicle leaves the starting point, for example. When the absolute difference E_d(t) of the power integrated value is derived, the process proceeds to step S214. E_d(t)=|ΣP_past(t)-ΣP_present(t)| …[1]

[0054] (Step S214) The control unit 14 judges whether the absolute difference E_d(t) of the power integrated value derived by the derivation unit 15 exceeds the reference value C. This judgment is made to reconsider whether the driving scenario needs to be reviewed. Therefore, the reference value C is set to an appropriate predetermined value, for example, when the change in the running power based on the driving scenario generated at the starting point deviates significantly from the running power profile set from the past running history, and it is judged that the driving scenario needs to be regenerated. If the absolute difference E_d(t) of the power integrated value exceeds the reference value C (E_d(t)>C) (S214, Yes), the process proceeds to step S209 to regenerate the driving scenario. On the other hand, if the absolute difference E_d(t) of the power integrated value does not exceed the reference value C (E_d(t)≦C) (S214, No), the process proceeds to step S212 to continue the driving mode control according to the current driving scenario.

[0055] (Step S215) The control unit 14 judges whether the charge rate of the battery 41 has reached an upper limit. This upper limit may be, for example, a charge rate at which the battery 41 is allowed to be overcharged. If the charge rate of the battery 41 has reached the upper limit (S215, Yes), the process proceeds to step S220. On the other hand, if the charge rate of the battery 41 has not reached the upper limit (S215, No), the process proceeds to step S216.

[0056] (Step S216) The control unit 14 judges whether the vehicle is traveling in a power generation possible range and the power generation request flag XF is set to "1". This judgment is made to judge whether the state of the vehicle corresponds to a condition for forcibly generating power. The power generation possible range refers to a range in which the vehicle is traveling at a high speed (e.g., 100 km / h or more) at which the internal combustion engine 21 can be used with high efficiency and efficient power generation is possible in the internal combustion engine mode. The power generation request flag XF is a flag indicating whether it is necessary to intentionally (forcibly) increase the amount of power generation between the departure point and the destination point, and is set to "1" or "0" as necessary in the process of generating a driving scenario described later. If the vehicle is in the power generation possible range and the power generation request flag XF = 1 (S216, Yes), the process proceeds to step S217. On the other hand, if the vehicle is not in the power generation possible range or the power generation request flag XF = 1 is not set (S216, No), the process proceeds to step S218.

[0057] (Step S217) The control unit 14 executes power generation using the electric motor 31 or other generators (not shown) so as to obtain the required power generation energy E_req determined in the process of generating an operation scenario, which will be described later. When power generation for obtaining the required power generation energy E_req is executed, the process proceeds to step S220.

[0058] (Step S218) The control unit 14 judges whether the vehicle is traveling in a power generation suppression area. A power generation suppression area is an area after the area where a large amount of electrical energy is expected to be recovered. An example of this power generation suppression area is a predetermined section before an exit interchange on a highway where regenerative energy is expected to be generated by deceleration. If the vehicle is traveling in a power generation suppression area (S218, Yes), the process proceeds to step S219. On the other hand, if the vehicle is not traveling in a power generation suppression area (S218, No), the process proceeds to step S220.

[0059] (Step S219) The control unit 14 executes power generation without considering regeneration (power generation) after the vehicle has traveled through the power generation suppression region. In general, in the power generation suppression region, power generation during travel in the region is suppressed to lower the charge storage rate of the battery 41 in advance so that the electric energy that can be expected to be acquired thereafter can be efficiently collected. In this embodiment, power generation during travel in the power generation suppression region, which is normally suppressed, is executed without being suppressed. This allows for efficient collection of the electric energy that can be expected to be acquired after the power generation suppression region, as well as highly efficient generation of electric energy by power generation during travel in the power generation suppression region. When power generation without considering regeneration after travel in the power generation suppression region is executed, the process proceeds to step S220.

[0060] (Step S220) The control unit 14 judges whether the vehicle has arrived at the destination point. If the vehicle has arrived at the destination point (S220, Yes), the process proceeds to step S201 to generate a driving scenario to the next destination point. On the other hand, if the vehicle has not yet arrived at the destination point (S220, No), the process proceeds to step S213 to reconsider whether the current driving scenario needs to be revised.

[0061] The driving scenario generation process shown in step S210 of Fig. 2A will be described with reference to Fig. 3A and Fig. 3B. Fig. 3A and Fig. 3B are flowcharts showing an example of the driving scenario generation process executed by the driving control device 10. The process of Fig. 3A and the process of Fig. 3B are connected by connectors M and N.

[0062] (Step S301) The setting unit 13 initializes the power generation request flag XF by setting it to “0.” When the power generation request flag XF is set to “0,” the process proceeds to step S302.

[0063] (Step S302) The setting unit 13 derives a consumption target energy E_tgt. The consumption target energy E_tgt is electric energy consumed during the running of the vehicle in order to make the charge rate of the battery 41 equal to the target charge rate SOC_tgt when the vehicle arrives at the destination. The consumption target energy E_tgt is derived by the following formula [2] based on the estimated regenerative energy E_est, the estimated generated energy E_gen, the required power generation energy E_req, the initial charge rate SOC_stt, and the full charge capacity C_f of the battery 41. Once the consumption target energy E_tgt is derived, the process proceeds to step S303. E_tgt = E_est + E_gen + E_req +(SOC_stt-SOC_tgt)×C_f …[2]

[0064] (Step S303) The setting unit 13 applies the threshold value P_swt to the traveling power profile to estimate a change in the battery 41's charge storage rate SOC_clc expected until the vehicle arrives at the destination from the current location. The threshold value P_swt is a value of the traveling power that provides a timing for switching between the first section in which only the electric motor 31 is driven for the vehicle traveling described above and the second section in which at least the internal combustion engine 21 is driven for the vehicle traveling, and can take a value between zero and the maximum power that the vehicle can output. The threshold value P_swt is preset with an initial value in which the low traveling power region in which the efficiency of the internal combustion engine 21 becomes poor becomes the first section, and this initial value is appropriately corrected according to the contents of the processing. The current location becomes the starting point of the vehicle in the driving scenario generation processing performed at the time of initial setting. When the change in the battery 41's charge storage rate SOC_clc is estimated, the processing proceeds to step S304.

[0065] An example of the change in the storage rate SOC_clc of the battery 41 estimated based on the traveling power is shown in Fig. 9 and Fig. 10. Fig. 9 illustrates an example of the change in the storage rate SOC_clc of the battery 41 when there is no target storage rate SOC_tgt at the destination. Fig. 10 illustrates an example of the change in the storage rate SOC_clc of the battery 41 when there is a target storage rate SOC_tgt at the destination.

[0066] 9 and 10, in the traveling power profile, in the first section (period not hatched or shaded in the figure) where the traveling power is equal to or greater than zero and equal to or less than the threshold, power is consumed by the powering control of the electric motor 31, and the battery 41's power storage rate SOC_clc decreases. On the other hand, in the first section (period hatched in the figure) where the traveling power is less than zero, the electric motor 31 performs regenerative braking, and power is charged, and the battery 41's power storage rate SOC_clc increases. Also, in the second section (period shaded in the figure) where the traveling power profile exceeds the threshold, in principle, there is no power consumption by the electric motor 31, and the battery 41's power storage rate SOC_clc is maintained, but during the period when high-speed traveling is performed, the battery 41's power storage rate SOC_clc increases due to charging by forced power generation.

[0067] (Step S304) The setting unit 13 judges whether or not there is an intermediate point where the storage rate SOC_clc of the battery 41, estimated to change from the current point to the destination point, reaches an upper limit or a lower limit value allowed for the battery 41. The allowable upper limit value of the battery 41 is, for example, a storage rate at which the battery 41 becomes overcharged, and the allowable lower limit value of the battery 41 is, for example, a storage rate at which the battery 41 becomes overdischarged. If there is an intermediate point where the storage rate SOC_clc reaches the allowable upper limit or the allowable lower limit value (S304, Yes), the process proceeds to step S305, and if there is no intermediate point where the storage rate SOC_clc reaches the allowable upper limit or the allowable lower limit value (S304, No), the process proceeds to step S306.

[0068] (Step S305) The setting unit 13 determines (confirms) the current threshold P_swt as the regular threshold to be applied from the undetermined point to the midpoint. The undetermined point in this step is the current point if this current midpoint is the midpoint where the charge rate SOC_clc reaches the allowable upper or lower limit of the battery 41 for the first time, and is the previous midpoint if this midpoint is the midpoint where the charge rate SOC_clc reaches the allowable upper or lower limit of the battery 41 for the second or subsequent time. There is no limit to the number of midpoints. Once the threshold from the undetermined point to the midpoint has been determined, the process proceeds to step S306.

[0069] (Step S306) Based on the charge rate SOC_clc of the battery 41 whose change is estimated, the setting unit 13 calculates an estimate of the motor traveling energy E_mg consumed by the motor 31 until the vehicle arrives at the destination from the current point. This motor traveling energy E_mg is calculated based on an integrated value of the traveling power in the first section where the traveling power is equal to or greater than zero in the traveling power profile to which the current threshold value P_swt is applied. If there is a threshold value determined in the above step S305, the current threshold value P_swt and the determined threshold value are each applied to the corresponding period to calculate the motor traveling energy E_mg. Once the motor traveling energy E_mg is calculated, the process proceeds to step S307.

[0070] (Step S307) The setting unit 13 judges whether the motor running energy E_mg is equal to the consumption target energy E_tgt (E_mg=E_tgt). This judgment is made to judge whether the consumption target energy E_tgt is being consumed without excess or deficiency at the current threshold value P_swt. If the motor running energy E_mg is equal to the consumption target energy E_tgt (S307, Yes), the process proceeds to step S309. On the other hand, if the motor running energy E_mg is not equal to the consumption target energy E_tgt (S307, No), the process proceeds to step S308.

[0071] (Step S308) The setting unit 13 executes a process of correcting the current threshold P_swt (threshold correction process). The threshold correction process will be described later. After the threshold P_swt is corrected, the process proceeds to step S303.

[0072] (Step S309) The setting unit 13 judges whether the current threshold value P_swt exceeds a predetermined running power value C_p. This value C_p is the running power at which the efficiency of the internal combustion engine 21 becomes poor, and indicates that it is necessary to increase the amount of power generation if the value is below this value. If the threshold value P_swt exceeds the value C_p (S309, Yes), the process proceeds to step S312. On the other hand, if the threshold value P_swt does not exceed the value C_p (S309, No), the process proceeds to step S310.

[0073] (Step S310) The setting unit 13 sets the power generation request flag XF to “1.” When the power generation request flag XF is set to “1,” the process proceeds to step S311.

[0074] (Step S311) The setting unit 13 increases the requested power generation energy E_req. More specifically, the setting unit 13 increases the previous requested power generation energy E_req by adding a small energy ΔE to it (E_req←E_req+ΔE). The small energy ΔE can be set arbitrarily based on the speed, resolution, etc. required for this process. When the requested power generation energy E_req is increased, the process proceeds to step S302.

[0075] (Step S312) The setting unit 13 determines (confirms) the current threshold P_swt as the regular threshold to be applied from the point where the threshold is not yet determined to the destination point. The point where the threshold is not yet determined in this step is the current point if the charge rate SOC_clc changes without ever reaching the allowable upper or lower limit value of the battery 41, and is the intermediate point where the charge rate SOC_clc last reached the allowable upper or lower limit value if the charge rate SOC_clc reaches the allowable upper or lower limit value of the battery 41 at least once. When the threshold from the undetermined point to the destination point is determined, the process proceeds to step S313.

[0076] (Step S313) The setting unit 13 generates data in which one or more thresholds determined in steps S305 and S312 are linked in a time series, and saves the generated data as a driving scenario to be applied to the vehicle's travel from the current point to the destination point. When the driving scenario is saved, this driving scenario generation process ends.

[0077] The threshold correction process shown in step S308 in Fig. 3A will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of the threshold correction process executed by the driving control device 10.

[0078] (Step S401) The setting unit 13 judges whether the electric motor running energy E_mg is greater than the consumed target energy E_tgt (E_mg>E_tgt). This judgment is made in order to judge how the threshold value P_swt should be corrected. If the electric motor running energy E_mg is greater than the consumed target energy E_tgt (S401, Yes), the process proceeds to step S402. On the other hand, if the electric motor running energy E_mg is not greater than the consumed target energy E_tgt (S401, No), the process proceeds to step S403.

[0079] (Step S402) The setting unit 13 reduces the threshold value P_swt because the electric energy is insufficient even if the estimated regenerative energy E_est is entirely consumed. Specifically, the setting unit 13 changes the current threshold value P_swt to a value reduced by a small amount of power ΔP (P_swt←P_swt-ΔP). The small amount of power ΔP can be set arbitrarily based on the performance of the power source, the difference between the electric motor running energy E_mg and the target energy consumption E_tgt, and the like. In addition to the above-mentioned method of reducing the threshold value P_swt by the fixed value of power ΔP, a method of setting an intermediate value between the current threshold value P_swt and the lower limit threshold value P_swt_min, which is the minimum threshold value that can be set, as a corrected threshold value (P_swt←(P_swt+P_swt_min) / 2) may be used as a method of reducing the threshold value P_swt in step S402 (binary search method). When the threshold value P_swt is reduced, this threshold value correction process ends.

[0080] (Step S403) The setting unit 13 increases the threshold value P_swt because the estimated regenerative energy E_est cannot be entirely consumed. Specifically, the setting unit 13 changes the current threshold value P_swt to a value increased by a small amount of power ΔP (P_swt←P_swt+ΔP). The small amount of power ΔP can be set arbitrarily based on the performance of the power source, the difference between the electric motor running energy E_mg and the consumption target energy E_tgt, and the like. In addition to the above-mentioned method of increasing the threshold value P_swt by the fixed value of power ΔP, a method of setting an intermediate value between the current threshold value P_swt and the upper limit threshold value P_swt_max, which is the maximum threshold value that can be set, as a corrected threshold value (P_swt←(P_swt+P_swt_max) / 2) may also be used as a method of increasing the threshold value P_swt in step S403 (binary search method). When the threshold value P_swt is increased, this threshold value correction process ends.

[0081] In addition, when generating a driving scenario, depending on the acquired driving power profile, speed profile, and initial power storage rate SOC_stt, it may be impossible to consume all of the estimated regenerative energy E_est and obtain the target power storage rate SOC_tgt at the time of arriving at the destination point at the same time. In such a case, the driving scenario may be generated by prioritizing either the consumption of all of the estimated regenerative energy E_est or the attainment of the target power storage rate SOC_tgt at the time of arriving at the destination point. Also, the driving scenario may be generated by prioritizing the power storage rate SOC_clc not reaching the allowable upper limit value or the allowable lower limit value.

[0082] 11 and 12 show an example of a method for determining the threshold value P_swt that is an operation scenario. Fig. 11 is a diagram for explaining an example where there is an intermediate point where the storage rate SOC_clc reaches the allowable upper limit value of the battery 41. Fig. 12 is a diagram for explaining an example where there is an intermediate point where the storage rate SOC_clc reaches the allowable lower limit value of the battery 41.

[0083] In FIG. 11, first, a threshold value (a) that is an initial value of the threshold value P_swt is applied to the traveling power profile to estimate a change (a) in the battery storage rate SOC_clc of the battery 41. However, with this change (a), the target battery storage rate SOC_tgt cannot be obtained when the vehicle arrives at the destination, so the threshold value P_swt is corrected downward to a threshold value (b1). Although the target battery storage rate SOC_tgt cannot be obtained with this threshold value (b1), there is an intermediate point P1 where the battery storage rate SOC_clc reaches an allowable upper limit value, so the threshold value from the starting point to the intermediate point P1 is determined to be the threshold value (b1). Then, finally, a threshold value (c1) is determined from the intermediate point P1 to the destination, which is a change (c1) that can obtain the target battery storage rate SOC_tgt when the vehicle arrives at the destination. With this method, a driving scenario is generated in which the switching control of the driving mode is performed based on the threshold value (b1) during the time from the starting point to the intermediate point P1, and the switching control of the driving mode is performed based on the threshold value (c1) during the time from the intermediate point P1 to the destination.

[0084] In FIG. 12, first, a threshold value (a) that is an initial value of the threshold value P_swt is applied to the traveling power profile to estimate a change (a) in the battery storage rate SOC_clc of the battery 41. However, with this change (a), the target battery storage rate SOC_tgt cannot be obtained when the vehicle arrives at the destination, so the threshold value P_swt is revised upward to a threshold value (b2). Although the target battery storage rate SOC_tgt cannot be obtained with this threshold value (b), there is an intermediate point P2 where the battery storage rate SOC_clc reaches the allowable lower limit value, so the threshold value from the starting point to the intermediate point P2 is determined to be the threshold value (b2). Then, finally, a threshold value (c2) is determined from the intermediate point P2 to the destination, which is a change (c2) that can obtain the target battery storage rate SOC_tgt when the vehicle arrives at the destination. With this method, a driving scenario is generated in which the switching control of the driving mode is performed based on the threshold value (b2) during the time from the starting point to the intermediate point P2, and the switching control of the driving mode is performed based on the threshold value (c2) during the time from the intermediate point P2 to the destination.

[0085] The above-described process estimates the change in power consumption, the amount of regenerative energy E_est recovered, and the highly efficient generated energy E_gen during one trip in which the vehicle travels from the departure point to the destination point, and based on these, a driving scenario can be generated that can improve fuel efficiency while achieving both efficient consumption of the target energy consumption E_tgt, including consumption of all of the estimated regenerative energy E_est, and attainment of the target energy storage rate SOC_tgt when the vehicle arrives at the destination point. Furthermore, if the deviation between the estimated value and the value obtained by actual driving becomes large, the driving scenario is reviewed, so that optimal driving control can always be achieved.

[0086] [Actions and Effects] As described above, the vehicle driving control device 10 according to this embodiment uses a driving power profile that indicates, in time series, the change in driving power generated by the power source during vehicle driving from the starting point to the destination based on the past driving history to quantitatively estimate the amount of regenerative energy E_est recovered at an early stage. In addition, the vehicle speed profile that indicates, in time series, the vehicle speed during vehicle driving from the starting point to the destination is used to estimate the generated energy E_gen obtained by highly efficient power generation during high-speed driving. Therefore, by utilizing these estimation results, it is possible to perform suitable vehicle driving control taking into account the target charge rate of the battery 41.

[0087] The driving control device 10 controls the vehicle to run using the electric motor 31 under driving conditions with poor engine efficiency, so that the internal combustion engine 21 can be driven in a region with as high efficiency as possible. When it is estimated that the regenerative energy is large, such as on a downhill road, the driving control device 10 controls the battery 41 to reduce its charge rate in advance to eliminate or reduce unrecovered energy. The driving control device 10 also controls the vehicle to generate power actively during high-speed driving with good engine efficiency, thereby increasing the period during which the vehicle can run using the electric motor 31, thereby improving fuel efficiency / electricity efficiency. Furthermore, the driving control device 10 sets the first and second sections and controls the driving mode so that the charge rate of the battery 41 does not exceed the allowable upper limit and does not fall below the allowable lower limit, thereby preventing the deterioration of the battery 41 from progressing. These controls enable the vehicle to suitably improve fuel efficiency while achieving both efficient consumption of the consumption target energy E_tgt, including the consumption of all of the estimated regenerative energy E_est, and the acquisition of the target charge rate SOC_tgt at the time the vehicle arrives at the destination.

[0088] Although one embodiment of the present disclosure has been described above, the present disclosure can be implemented with appropriate modifications. The present disclosure can be understood not only as a cruise control device, but also as a cruise control method executed by a cruise control device having a processor and a memory, a cruise control program, a computer-readable non-transitory storage medium storing the cruise control program, a vehicle equipped with a cruise control device, and the like. [Industrial Applicability]

[0089] The present disclosure is useful for a cruise control device mounted on a vehicle or the like. [Explanation of symbols]

[0090] 10 Driving control device 11 Acquisition Department 12 Estimation part 13 Setting section 14 Control section 15 Derivation part 20 Internal Combustion Engine ECU 21 Internal Combustion Engine 22 Transmission 30 Electric motor ECU 31 Electric motor 40 Battery ECU 41 Batteries 50 EPSEC 51 EPS equipment 60 Brake ECU 61 Brake device 70 Driving control ECU 80 Driving assistance ECU 90 Autonomous Driving ECU 100 Manager ECU 110 Storage section 120 Communications Department 200 In-vehicle Network

Claims

1. A driving control device mounted on a vehicle having an electric motor and an internal combustion engine as a power source, A first acquisition unit that acquires a destination point of the vehicle; A second acquisition unit that acquires a past travel history from a starting point to the destination point; a third acquisition unit that acquires a target power storage rate that is a target power storage rate of a battery mounted on the vehicle at a time when the vehicle arrives at the destination point; an estimation unit that estimates an expected amount of generated energy, which is energy that can be generated in the vehicle until the vehicle arrives at the destination point, based on the driving history; a setting unit that sets a first section in which only the electric motor is driven for traveling and a second section in which at least the internal combustion engine is driven for traveling based on the predicted amount of generated energy and the target charge rate; a control unit that controls traveling of the vehicle based on the first section and the second section, A driving control device, wherein the driving history includes information showing, in a time series, changes in power that occurred in the power source when the vehicle traveled from the starting point to the destination point in the past, and information showing, in a time series, changes in the speed of the vehicle when the vehicle traveled from the starting point to the destination point in the past.

2. 2. The driving control device according to claim 1, wherein the estimation unit determines a period in the driving history during which the power generated in the power source is negative as a recovery period in which energy can be recovered, and estimates a time integral value of the magnitude of the power generated in the power source during the recovery period as at least a part of the predicted amount of generated energy.

3. 3. The driving control device according to claim 1, wherein the estimation unit determines a period in the driving history during which the vehicle travels at or above a predetermined speed as a power generation period during which highly efficient power generation is possible by driving the internal combustion engine, and estimates the energy generated during the power generation period as at least a part of the predicted amount of generated energy.

4. 4. The driving control device according to claim 1, wherein the setting unit sets the first section and the second section such that the predicted amount of generated energy is entirely consumed when the vehicle arrives at the destination point.

5. The driving control device according to claim 1 , wherein the setting unit sets the first section and the second section such that the charge rate of the battery does not exceed an allowable upper limit value or does not fall below an allowable lower limit value.

6. a derivation unit that derives a difference between a time integral value of a magnitude of power generated in the power source based on the driving history up to a current point and a time integral value of a magnitude of power generated in the power source based on actual driving, 6. The driving control device according to claim 1, wherein the setting unit resets the first section and the second section from the current point to the destination point when an absolute value of the difference derived by the derivation unit is equal to or greater than a predetermined reference value.

7. A driving control method executed by a driving control device mounted on a vehicle having an electric motor and an internal combustion engine as power sources, comprising: obtaining a destination point for the vehicle; acquiring a past travel history from a starting point to the destination point; acquiring a target charge storage rate, which is a target charge storage rate of a battery mounted on the vehicle at a time when the vehicle arrives at the destination point; estimating an expected amount of generated energy, which is energy that can be generated in the vehicle until the vehicle arrives at the destination point, based on the travel history; setting a first section in which only the electric motor is driven for traveling and a second section in which at least the internal combustion engine is driven for traveling based on the predicted amount of generated energy and the target charge rate; and controlling the traveling of the vehicle based on the first section and the second section. A driving control method, wherein the driving history includes information showing, in a time series, changes in power that occurred in the power source when the vehicle traveled from the starting point to the destination point in the past, and information showing, in a time series, changes in the speed of the vehicle when the vehicle traveled from the starting point to the destination point in the past.

8. A driving control program to be executed by a computer of a driving control device mounted on a vehicle equipped with an electric motor and an internal combustion engine as a power source, obtaining a destination point for the vehicle; acquiring a past travel history from a starting point to the destination point; acquiring a target charge storage rate, which is a target charge storage rate of a battery mounted on the vehicle at a time when the vehicle arrives at the destination point; estimating an expected amount of generated energy, which is energy that can be generated in the vehicle until the vehicle arrives at the destination point, based on the travel history; setting a first section in which only the electric motor is driven for traveling and a second section in which at least the internal combustion engine is driven for traveling based on the predicted amount of generated energy and the target charge rate; and controlling the traveling of the vehicle based on the first section and the second section. A driving control program, wherein the driving history includes information showing, in a time series, the changes in power that occurred in the power source when the vehicle traveled from the starting point to the destination point in the past, and information showing, in a time series, the changes in the speed of the vehicle when the vehicle traveled from the starting point to the destination point in the past.

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