Display control device, display control method and computer program for display control

Abstract

To provide a display control device that can reduce frequencies at which display which makes a driver in a vehicle feel uneasy is performed.SOLUTION: A display control device comprises: a determining part 32 that determines whether a state of a battery 13 of a vehicle 10 satisfies a predetermined restriction condition or not; a notifying part 35 that, when the state of the battery 13 satisfies the restriction condition, notifies a driver in the vehicle 10, through a notifying instrument 15 provided on the vehicle 10, of output-restriction caution for restricting output of a motor 12 loaded on the vehicle 10; and a condition setting part 34 that sets, to a first condition, a restriction condition at the time when an acceleration / deceleration control mode in which acceleration and deceleration of the vehicle 10 is controlled in accordance with an inter-vehicle distance between a preceding vehicle and the vehicle 10 is not applied, and sets, to a second condition that is stricter than the first condition, a restriction condition at the time when the acceleration / deceleration control mode is applied.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a display control device, a display control method, and a display control computer program for controlling notifications related to the state of a vehicle. [Background technology]

[0002] In order to extend the driving range of electric vehicles, a technology has been proposed that limits the power demanded by the traction motor when the remaining battery capacity is lower than a predetermined capacity, and displays the limited state on a warning display device (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-147592 Summary of the Invention [Problem to be solved by the invention]

[0004] When a driving mode is applied in which the acceleration / deceleration of the vehicle is automatically controlled according to the distance between the vehicle and the preceding vehicle, there are not many situations in which a relatively large amount of power is required to be supplied to the motor, such as situations requiring sudden acceleration. Therefore, if a warning notification about a limit on the required power is displayed while such a driving mode is applied, the vehicle will not actually be controlled to reach the limit, which could cause the driver to feel uneasy that some kind of abnormality has occurred in the vehicle control system.

[0005] Therefore, an object of the present invention is to provide a display control device that can reduce the frequency of notifications that make a vehicle driver feel uneasy. [Means for solving the problem]

[0006] A display control device according to one embodiment has a determination unit that determines whether the state of the vehicle's battery satisfies a predetermined restriction condition; a notification processing unit that, when the state of the battery satisfies the restriction condition, notifies the driver of the vehicle via a notification device installed in the vehicle of an output restriction warning that limits the output of the motor installed in the vehicle; and a condition setting unit that sets the restriction condition to a first condition when an acceleration / deceleration control mode that controls the acceleration / deceleration of the vehicle according to the distance between the vehicle and a preceding vehicle is not applied, and sets the restriction condition to a second condition that is stricter than the first condition when the acceleration / deceleration control mode is applied.

[0007] In one embodiment, the display control device further has a prediction unit that determines whether a prediction condition for predicting that the driver will operate the accelerator is satisfied based on the driving conditions of other vehicles driving around the vehicle, the distance between the other vehicles and the vehicle, or the driver's behavior, and when the prediction condition is satisfied, the condition setting unit sets the restriction condition to the first condition even if the acceleration / deceleration control mode is set.

[0008] A display control method according to another embodiment includes determining whether the state of the vehicle's battery satisfies a predetermined restriction condition, and if the state of the battery satisfies the restriction condition, notifying the driver of the vehicle via a notification device installed in the vehicle of an output restriction warning that limits the output of a motor installed in the vehicle, setting the restriction condition when an acceleration / deceleration control mode that controls the acceleration / deceleration of the vehicle according to the distance between the vehicle and a preceding vehicle to a first condition, and setting the restriction condition when the acceleration / deceleration control mode is applied to a second condition that is stricter than the first condition.

[0009] In yet another embodiment, a computer program for display control includes instructions to cause a processor mounted on the vehicle to execute the following: determine whether the state of the vehicle's battery satisfies a predetermined restriction condition; if the state of the battery satisfies the restriction condition, notify the driver of the vehicle via a notification device installed in the vehicle of an output restriction warning that limits the output of the motor mounted on the vehicle; set the restriction condition when an acceleration / deceleration control mode that controls the acceleration / deceleration of the vehicle according to the distance between the vehicle and a preceding vehicle is not applied to a first condition; and set the restriction condition when the acceleration / deceleration control mode is applied to a second condition that is stricter than the first condition. [Effects of the Invention]

[0010] The display control device according to the present disclosure has the effect of reducing the frequency of notifications that make the driver of the vehicle feel uneasy. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a vehicle in which a display control device is implemented; [Figure 2] FIG. 2 is a functional block diagram of a processor of the electronic control device related to display control processing. [Figure 3] FIG. 2 is a diagram illustrating an outline of a display control process according to the present embodiment. [Figure 4] 10 is an operation flowchart of a display control process according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] A display control device, a display control method executed on the display control device, and a computer program for display control will be described below with reference to the drawings. When the state of the vehicle's battery satisfies a predetermined limiting condition, the display control device notifies the driver of the vehicle via a notification device provided in the vehicle of an output limiting warning indicating that the output of a motor mounted on the vehicle will be limited. Furthermore, the display control device sets the limiting condition to a first condition when a driving mode (hereinafter referred to as an acceleration / deceleration control mode) that controls the acceleration / deceleration of the vehicle according to the distance between the vehicle and a preceding vehicle is not applied, and sets the limiting condition to a second condition that is stricter than the first condition when the acceleration / deceleration control mode is applied.

[0013] 1 is a schematic diagram of a vehicle in which a display control device is implemented. In this embodiment, the vehicle 10 is a battery electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and a powertrain 11 of the vehicle 10 includes a motor 12 as a driving power source. The vehicle 10 also has a battery 13 for supplying power to each part of the vehicle 10, an external sensor 14, a notification device 15, and an electronic control unit (ECU) 16.

[0014] The exterior sensor 14 is a sensor that generates an exterior sensor signal that indicates the situation around the vehicle 10, and is, for example, a camera that is installed so as to be able to capture images of the area around the vehicle 10, or a distance measurement sensor such as a LiDAR or radar. The vehicle 10 may be provided with a plurality of exterior sensors 14 with different detectable ranges or types. Each time the exterior sensor 14 generates an exterior sensor signal, the exterior sensor 14 outputs the generated exterior sensor signal to the ECU 16.

[0015] The notification device 15 is an example of a notification unit and is provided in the passenger compartment of the vehicle 10. The notification device 15 has, for example, at least one of a speaker, a light source, or a display device. When the notification device 15 receives a notification signal representing a predetermined notification to the driver from the ECU 16, the notification device 15 notifies the driver by sound from the speaker, light from the light source, or displaying a message or icon on the display device. When the notification device 15 has two or more types of devices, the notification may be given to the driver via each of the two or more types of devices.

[0016] The ECU 16 is capable of controlling the vehicle 10 in accordance with an acceleration / deceleration control mode that automatically controls the acceleration / deceleration of the vehicle 10 in accordance with the distance between the preceding vehicle and the vehicle 10. The acceleration / deceleration control may be executed as one function of driving assistance control or one function of automatic driving control. That is, the driving assistance mode and the automatic driving mode are examples of acceleration / deceleration control modes.

[0017] The ECU 16 is an example of a display control device, and executes a predetermined notification according to the state of the battery 13 via the notification device 15.

[0018] The ECU 16 has a communication interface 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 may each be configured as a separate circuit, or may be integrated into a single integrated circuit.

[0019] The communication interface 21 has an interface circuit for connecting the ECU 16 to other devices. The communication interface 21 passes signals from the outside-vehicle sensors 14 to the processor 23. Furthermore, the communication interface 21 outputs control signals for the powertrain 11 received from the processor 23 to the powertrain 11. Furthermore, the communication interface 21 outputs notification signals received from the processor 23, which indicate various notifications to the driver, to the notification device 15.

[0020] The memory 22 is an example of a storage unit and includes a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores various data used in the display control process executed by the processor 23 or generated during the display control process. Furthermore, the memory 22 stores various data used in the control of the vehicle 10 by the processor 23 in accordance with the applied driving mode or generated during the control of the vehicle 10.

[0021] The processor 23 includes one or more central processing units (CPUs) and their peripheral circuits. The processor 23 may further include other arithmetic circuits such as a logic unit, a numerical calculation unit, or a graphics processing unit. The processor 23 executes display control processing. Furthermore, the processor 23 executes control of the vehicle 10 according to the applied driving mode.

[0022] 2 is a functional block diagram of the processor 23 for the display control process and the vehicle control process related to the display control process. The processor 23 has a mode setting unit 31, a determination unit 32, a prediction unit 33, a condition setting unit 34, a notification processing unit 35, and a driving control unit 36. Each of these units in the processor 23 is a functional module realized by, for example, a computer program running on the processor 23. Alternatively, each of these units may be a dedicated arithmetic circuit provided in the processor 23.

[0023] The mode setting unit 31 sets the driving mode to be applied to the vehicle 10 to a mode specified by an operation signal from an operation device (not shown) provided in the cabin of the vehicle 10. That is, when the operation signal indicates that a driving mode including acceleration / deceleration control (a driving assistance mode or an autonomous driving mode) is to be set, the mode setting unit 31 applies the driving mode to the vehicle 10. On the other hand, when the operation signal indicates that a manual driving mode indicating manual driving by the driver is to be set, the mode setting unit 31 applies the manual driving mode to the vehicle 10. Every time the driving mode to be applied to the vehicle 10 is changed via operation of the operation device, the mode setting unit 31 notifies the prediction unit 33, the condition setting unit 34, and the driving control unit 36 ​​of the changed driving mode.

[0024] The determination unit 32 receives a status signal representing the status of the battery 13 from the battery 13 at predetermined intervals (for example, every one to several seconds), and determines whether the status of the battery 13 represented by the status signal satisfies predetermined limiting conditions. The status of the battery 13 is, for example, the state of charge (SOC) of the battery 13, the temperature of the battery 13, or both. The limiting conditions are conditions for determining whether to issue an output limit warning for the motor 12.

[0025] When the state of battery 13 indicated by the state signal is a charging state, the limiting condition is defined by a threshold value (hereinafter referred to as a capacity threshold value) for the remaining capacity of battery 13. In this case, when the remaining capacity of battery 13 indicated by the charging state is equal to or less than the capacity threshold value, determination unit 32 determines that the limiting condition is satisfied, and when the remaining capacity is greater than the capacity threshold value, determines that the limiting condition is not satisfied.

[0026] Furthermore, when the state of the battery 13 represented by the state signal is the temperature of the battery 13, the limiting condition is defined by a threshold value (hereinafter referred to as the temperature threshold value) for the temperature of the battery 13. In this case, the determination unit 32 determines that the limiting condition is satisfied when the temperature of the battery 13 is equal to or higher than the temperature threshold value, and determines that the limiting condition is not satisfied when the temperature is lower than the temperature threshold value.

[0027] In addition, if the status signal indicates both the charge state and temperature of the battery 13, the judgment unit 32 may judge that the restriction condition is satisfied when the remaining capacity of the battery 13 becomes equal to or less than the capacity threshold or when the temperature of the battery 13 becomes equal to or greater than the temperature threshold.

[0028] The limiting conditions are set by the condition setting unit 34 based on the applied operation mode or the prediction result by the prediction unit 33. The setting of the limiting conditions will be described in detail later.

[0029] As will be described later, the limiting conditions when the applied driving mode is an acceleration / deceleration control mode (driving assistance mode or automatic driving mode) are set to be stricter than the limiting conditions when the applied driving mode is a manual driving mode. Therefore, when the applied driving mode is the acceleration / deceleration control mode, the limiting conditions are less likely to be met compared to when the applied driving mode is a manual driving mode, and as a result, the output limit warning is less likely to be notified.

[0030] Every time the determination unit 32 determines whether or not the limiting condition is satisfied, it notifies the notification processing unit 35 of the determination result.

[0031] The above-described limiting condition for determining whether to display a warning regarding the output limit of the motor 12 may be different from the limiting condition for determining whether to actually limit the output of the motor 12 (hereinafter referred to as the output limiting condition to distinguish it from the limiting condition regarding the notification of the output limit warning). For example, the output limiting condition is set to be more easily satisfied than the limiting condition regarding the notification of the output limiting warning. Therefore, when the state of the battery 13 represented by the status signal is a charging state, the capacity threshold for the output limiting condition is set to a value greater than the capacity threshold for the notification of the output limiting warning. Furthermore, when the state of the battery 13 represented by the status signal is a temperature, the temperature threshold for the output limiting condition is set to a value smaller than the temperature threshold for the notification of the output limiting warning.

[0032] Every time the determination unit 32 determines whether or not the output limiting condition is satisfied, it notifies the driving control unit 36 ​​of the determination result.

[0033] When the driving assistance mode or the autonomous driving mode is applied, the prediction unit 33 determines at each predetermined period whether the prediction conditions for predicting that the driver of the vehicle 10 will perform an accelerator operation are satisfied based on the driving conditions of other vehicles traveling around the vehicle 10, the distance between the other vehicles and the vehicle 10, or the behavior of the driver.

[0034] For example, the following four conditions are set as prediction conditions. If any of the following conditions is satisfied, the prediction unit 33 determines that the prediction condition is satisfied, and if none of the conditions is satisfied, the prediction unit 33 determines that the prediction condition is not satisfied. Note that the prediction conditions are not limited to these, and other prediction conditions may be set, or any of the following four conditions may be omitted. (i) The distance between the vehicle 10 and a preceding vehicle traveling ahead of the vehicle 10 is equal to or greater than a predetermined distance. (ii) The distance between the vehicle 10 and the following vehicle traveling behind the vehicle 10 is equal to or less than a predetermined distance. (iii) The speed of the vehicle 10 is slower than the average speed of other vehicles traveling around the vehicle 10 (hereinafter referred to as the speed of the traffic flow). (iv) The vehicle 10 is traveling in the driving lane, and the driver has turned on the turn signal on the passing lane side.

[0035] To detect a leading vehicle, the prediction unit 33 detects other vehicles traveling around the vehicle 10. To this end, the prediction unit 33 detects other vehicles by inputting exterior sensor signals, obtained by the exterior sensors 14, that indicate the conditions of the area around the vehicle 10, into a classifier that has been trained in advance to detect other vehicles traveling around the vehicle 10. This classifier can be a classifier based on a deep neural network (DNN) with a convolutional neural network (CNN) type architecture or an attention mechanism.

[0036] When the external sensor 14 is a camera installed to capture images of the surroundings of the vehicle 10 and the external sensor signal is an image, the classifier detects an object region representing another vehicle detected in the image. Furthermore, the prediction unit 33 detects lane lines by inputting the image generated by the camera into a classifier for lane line detection that has been trained in advance to detect lane lines. The classifier for lane line detection may be a DNN for semantic segmentation, such as a U-net. Alternatively, the classifier for detecting other vehicles may be trained in advance to detect lane lines as well. The prediction unit 33 then determines the region in the image between the two closest lane lines to the vehicle 10 as the current lane region representing the lane in which the vehicle 10 is traveling. Among the detected other vehicles, the prediction unit 33 may identify the vehicle whose bottom edge of the object region in the image is included in the current lane region and is closest to the bottom of the image as the leading vehicle. Alternatively, the prediction unit 33 may identify, as the preceding vehicle, one of the detected other vehicles that is located in a direction corresponding to the traveling direction of the vehicle 10. Then, the prediction unit 33 estimates the distance from the vehicle 10 to the preceding vehicle.

[0037] The position of the bottom edge of the object area representing the leading vehicle is assumed to represent the position where the leading vehicle touches the road surface. Furthermore, the position on the image corresponds one-to-one with the direction as seen from the camera that generated the image. Therefore, the prediction unit 33 can estimate the distance and direction from the camera to the leading vehicle by referring to the position of the bottom edge of the object area representing the leading vehicle on the image and parameters such as the camera installation height, shooting direction, and angle of view.

[0038] Furthermore, when the external sensor 14 is a distance measurement sensor, the prediction unit 33 identifies, among the other detected vehicles, a vehicle detected in a direction corresponding to the traveling direction of the vehicle 10 as the preceding vehicle. The prediction unit 33 then estimates the distance measured in the direction in which the detected preceding vehicle appears as the distance between the vehicle 10 and the preceding vehicle.

[0039] Furthermore, the prediction unit 33 determines, among the other detected vehicles, a vehicle traveling in the own lane area behind the vehicle 10 as a following vehicle. The prediction unit 33 then estimates the inter-vehicle distance between the vehicle 10 and the following vehicle by executing a process similar to that used to estimate the inter-vehicle distance between the vehicle 10 and the preceding vehicle.

[0040] The prediction unit 33 may also estimate the inter-vehicle distance between the vehicle 10 and each of the other vehicles by performing a process similar to that for estimating the inter-vehicle distance from the preceding vehicle for each of the other detected vehicles. Furthermore, the prediction unit 33 performs a tracking process such as Byte Track to track each of the other detected vehicles, thereby determining the change in the inter-vehicle distance in the traveling direction of the vehicle 10 for each of the other vehicles over the most recent predetermined period. The prediction unit 33 then determines the average speed of each of the other vehicles over the most recent predetermined period based on the average value of the speed of the vehicle 10 measured by a vehicle speed sensor (not shown) over the most recent predetermined period and the change in the inter-vehicle distance of each of the other vehicles, and further determines the speed of the traffic flow by averaging the average speeds of each of the other vehicles.

[0041] When the distance to the preceding vehicle is equal to or greater than a predetermined distance, there is a possibility that the accelerator will be operated so that the vehicle 10 will catch up with the preceding vehicle, and therefore the prediction unit 33 determines that the prediction condition is satisfied.

[0042] Furthermore, if the distance between the vehicle 10 and the following vehicle is equal to or less than a predetermined distance, there is a possibility that the accelerator will be operated so that the vehicle 10 moves away from the following vehicle, and therefore the prediction unit 33 determines that the prediction condition is satisfied. Note that even if the estimated distance to the following vehicle is equal to or less than a predetermined distance, if the distance between the vehicle 10 and the preceding vehicle is equal to or less than a predetermined distance, there is a risk that the vehicle 10 will catch up with the preceding vehicle if the vehicle 10 accelerates. Therefore, in such a case, the prediction unit 33 may determine that the prediction condition is not satisfied.

[0043] Furthermore, if the average speed of the vehicle 10 over a recent predetermined period is slower than the speed of the traffic flow by a predetermined speed or more, the driver may accelerate the vehicle 10 so that the speed of the vehicle 10 approaches the speed of the traffic flow. In such a case, the prediction unit 33 may determine that the prediction condition is satisfied.

[0044] Furthermore, the prediction unit 33 may identify the lane in which the vehicle 10 is traveling by referring to map information and the position of the vehicle 10 determined by a receiver of a positioning system mounted on the vehicle 10. When the lane in which the vehicle 10 is traveling is the driving lane, if the ECU 16 receives a signal from the turn signal indicating that the turn signal for the passing lane is turned on, the driver is likely to change lanes of the vehicle 10 into the passing lane and accelerate the vehicle 10. Therefore, in such a case as well, the prediction unit 33 may determine that the prediction condition is satisfied.

[0045] Every time the prediction unit 33 determines whether the prediction condition is satisfied, it notifies the condition setting unit 34 of the determination result.

[0046] The condition setting unit 34 sets the restriction conditions based on the determination result of whether the applied driving mode or the prediction conditions are satisfied. In particular, if the prediction conditions are not satisfied, the condition setting unit 34 sets the restriction conditions according to the applied driving mode. In this embodiment, if the applied driving mode is a manual driving mode, i.e., if the acceleration / deceleration control mode is not applied, the condition setting unit 34 sets the restriction conditions to a relatively lenient first condition. On the other hand, if the applied driving mode is a driving assistance driving mode or an autonomous driving mode, i.e., if the acceleration / deceleration control mode is applied, the condition setting unit 34 sets the restriction conditions to a relatively strict second condition. That is, the capacity threshold in the second condition is set to a value relatively lower than the capacity threshold in the first condition, and the temperature threshold in the second condition is set to a value relatively higher than the temperature threshold in the first condition. Therefore, an output restriction warning is less likely to be issued when the restriction conditions are set to the second condition than when they are set to the first condition.

[0047] On the other hand, when the prediction condition is satisfied, the condition setting unit 34 sets the limiting condition to the first condition regardless of the applied operation mode. Therefore, even if the applied operation mode is an operation mode including acceleration / deceleration control, the likelihood of receiving a notification regarding an output limit warning is about the same as when the manual operation mode is applied.

[0048] The condition setting unit 34 further sets an output limiting condition based on the set limiting condition. As described above, the output limiting condition is set as a condition that is easier to satisfy than the limiting condition related to the warning display. For example, the condition setting unit 34 sets a value that is several percent higher than the capacity threshold set as the limiting condition as the capacity threshold for the output limiting condition. In addition, the condition setting unit 34 sets a value that is several degrees lower than the temperature threshold set as the limiting condition as the temperature threshold for the output limiting condition.

[0049] Every time the limiting conditions and output limiting conditions are set or changed, the condition setting unit 34 notifies the determination unit 32 of the set or changed limiting conditions and output limiting conditions.

[0050] When the notification processing unit 35 is notified by the determination unit 32 that the restriction condition has been satisfied, the notification processing unit 35 notifies the driver via the notification device 15 of an output restriction warning indicating that the output of the motor 12 will be restricted. For example, when the restriction condition has been satisfied, the notification processing unit 35 displays a message or an icon representing the output restriction warning on a display device, which is an example of the notification device 15. Alternatively, when the restriction condition has been satisfied, the notification processing unit 35 causes a light source, which is another example of the notification device 15 and corresponds to the output restriction warning, to emit light or blink. Alternatively, when the restriction condition has been satisfied, the notification processing unit 35 outputs a sound representing the output restriction warning from a speaker, which is yet another example of the notification device 15. Note that the notification processing unit 35 may notify the driver of the output restriction warning via two or more types of notification devices 15.

[0051] Furthermore, when the determination unit 32 notifies the notification processing unit 35 that the limiting condition is no longer satisfied, the notification processing unit 35 stops issuing the output limit warning.

[0052] The driving control unit 36 ​​controls the driving of the vehicle 10 according to the applied driving mode.

[0053] When the manual driving mode is applied, the driving control unit 36 ​​refers to a map showing the relationship between the accelerator opening of the accelerator device (not shown), the rotation speed of the engine or motor 12 included in the powertrain 11, and the target torque. The driving control unit 36 ​​then sets the target torque according to the accelerator opening corresponding to the driver's accelerator pedal depression amount according to the map. However, if the output limiting condition is satisfied, the driving control unit 36 ​​modifies the target torque as necessary so that the power required by the motor 12 is equal to or less than the upper limit under the output limit. The driving control unit 36 ​​then generates a control signal for the powertrain 11 according to the target torque and outputs the generated control signal to the powertrain 11. In this case, the driving control unit 36 ​​controls the powertrain 11 according to feedback control such as PID control so that the actual output torque approaches the target torque. Furthermore, when the driver depresses the brake pedal, the driving control unit 36 ​​sets a target torque for decelerating the vehicle 10 according to the driver's brake pedal depression amount, and controls the powertrain 11, including the brake device (not shown) and the motor 12, according to the set target torque.

[0054] Furthermore, while the driving assistance mode or the autonomous driving mode is applied, the driving control unit 36 ​​controls the powertrain 11 and the brake device so that the vehicle 10 travels at a target vehicle speed. Furthermore, the driving control unit 36 ​​controls the powertrain 11 and the brake device so that a predetermined distance or more is maintained between the vehicle 10 and a preceding vehicle traveling ahead of the vehicle 10 in the vehicle's own lane. The target vehicle speed is set via an in-vehicle operating device. Alternatively, the driving control unit 36 ​​may identify the road section on which the vehicle 10 is traveling and the legal speed of the road section based on map information indicating the legal speed of each road section and the current position of the vehicle 10, and set the target vehicle speed to the identified legal speed. Such map information is pre-stored in the memory 22 or an on-board storage device (not shown) for storing map information. The current position of the vehicle 10 may be determined by a satellite positioning system receiver (not shown) installed in the vehicle 10.

[0055] The driving control unit 36 ​​may perform the same processing as that described for the prediction unit 33 to detect the preceding vehicle and estimate the inter-vehicle distance between the vehicle 10 and the preceding vehicle. Alternatively, the driving control unit 36 ​​may obtain from the prediction unit 33 the detection result of the preceding vehicle and the estimated inter-vehicle distance between the vehicle 10 and the preceding vehicle.

[0056] If the estimated distance to the preceding vehicle (hereinafter, sometimes simply referred to as the inter-vehicle distance) is less than a predetermined distance, the cruise control unit 36 ​​sets a target acceleration / deceleration rate to decelerate the vehicle 10. In this case, the cruise control unit 36 ​​sets the target acceleration / deceleration rate so that the deceleration rate increases as the inter-vehicle distance to the preceding vehicle decreases or as the relative speed of the vehicle 10 relative to the preceding vehicle increases. On the other hand, if the estimated inter-vehicle distance to the preceding vehicle is equal to or greater than the predetermined distance, the cruise control unit 36 ​​sets the target acceleration / deceleration rate so that the speed of the vehicle 10 approaches the target vehicle speed. However, if the speed of the preceding vehicle is slower than the target vehicle speed, the cruise control unit 36 ​​sets the target acceleration / deceleration rate so that the inter-vehicle distance becomes the predetermined distance and the relative speed between the vehicle 10 and the preceding vehicle becomes zero. To achieve this, the cruise control unit 36 ​​sets the target acceleration / deceleration rate based on, for example, a relational expression between the inter-vehicle distance, the relative speed, and the target acceleration / deceleration rate. The cruise control unit 36 ​​then calculates a target torque according to the set target acceleration / deceleration rate. However, even in this case, if the output limit is satisfied, the driving control unit 36 ​​corrects the target torque as necessary so that the power required by the motor 12 is equal to or less than the upper limit under the output limit. The driving control unit 36 ​​then generates a control signal for the powertrain 11 in accordance with the target torque, and outputs the generated control signal to the powertrain 11 including the motor 12 and to the brake device.

[0057] FIG. 3 is a diagram illustrating an overview of the display control process according to this embodiment. In FIG. 3, the horizontal axis represents elapsed time. In the upper time chart, the vertical axis represents the remaining charge of the battery 13, and graph 300 represents the change over time in the remaining charge of the battery 13. In the lower time chart, the vertical axis represents whether or not an output limit warning is issued. If the value on the vertical axis is ON, it indicates that an output limit warning is issued, and if the value on the vertical axis is OFF, it indicates that an output limit warning is not issued. Graph 310 represents the change over time in whether or not an output limit warning is issued when a driving mode including acceleration / deceleration control (driving assistance mode or autonomous driving mode) is not applied. Graph 311 represents the change over time in whether or not an output limit warning is issued when a driving mode including acceleration / deceleration control is applied.

[0058] When the acceleration / deceleration control mode is not applied, the capacity threshold Th1 is set to a relatively large value. In contrast, as shown in graph 300, the remaining capacity of the battery 13 decreases over time and becomes equal to or less than the capacity threshold Th1 at time t1. Therefore, as shown in graph 310, an output limit warning is issued after time t1.

[0059] On the other hand, when the acceleration / deceleration control mode is applied, the capacity threshold Th2 is set to a relatively small value. Therefore, as shown in graph 300, the remaining charge of battery 13 becomes equal to or less than the capacity threshold Th2 at time t2, which is later than time t1. Therefore, as shown in graph 311, an output limit warning is not issued at time t1, but is issued after time t2. In this way, when the acceleration / deceleration control mode is applied, an output limit warning is less likely to be issued than when such an operation mode is not applied.

[0060] FIG. 4 is an operational flowchart of the display control process according to this embodiment.

[0061] The prediction unit 33 determines whether a prediction condition for predicting that the driver will perform an accelerator operation is satisfied (step S101). If the prediction condition is satisfied (step S101—Yes), the condition setting unit 34 sets the restriction condition to a relatively lenient first condition (step S102). On the other hand, if the prediction condition is not satisfied (step S101—No), the condition setting unit 34 determines whether the applied driving mode is a driving mode including acceleration / deceleration control (step S103). If the applied driving mode is a driving mode that does not include acceleration / deceleration control, i.e., if a manual driving mode is applied (step S103—No), the condition setting unit 34 sets the restriction condition to the relatively lenient first condition (step S102). On the other hand, if the applied driving mode is a driving mode that includes acceleration / deceleration control (a driving assistance mode or an automated driving mode) (step S103—Yes), the condition setting unit 34 sets the restriction condition to a stricter second condition (step S104).

[0062] After step S102 or S104, determination unit 32 determines whether the state of battery 13 satisfies the limiting condition (step S105). If the limiting condition is satisfied (step S105-Yes), notification processing unit 35 notifies the driver of an output limit warning via notification device 15 (step S106). If the limiting condition is not satisfied in step S105 (step S105-No), or after step S106, processor 23 ends the display control process.

[0063] As described above, this display control device notifies the driver of a motor output limit warning via a notification device when the state of the vehicle's battery satisfies the limiting conditions. The display control device then sets stricter limiting conditions when the acceleration / deceleration control mode is applied than limiting conditions when the acceleration / deceleration control mode is not applied. This makes it less likely that a motor output limit warning will be issued when the acceleration / deceleration control mode is applied, so the display control device can reduce the frequency of notifications that make the driver feel uneasy. Furthermore, when it is predicted that the driver will operate the accelerator, relatively looser limiting conditions are set even when the acceleration / deceleration control mode is applied, so the display control device can notify the driver of a motor output limit warning at an appropriate time.

[0064] According to a modified example, when the acceleration / deceleration control mode is applied, the condition setting unit 34 may set the restrictive condition to a relatively strict second condition, regardless of whether the prediction condition regarding the accelerator operation is satisfied. In this case, the processing by the prediction unit 33 may be omitted.

[0065] A computer program that realizes the functions of the processor 23 of the ECU 13 according to the above embodiment or each of the variations may be provided in a form recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium or an optical recording medium. [Explanation of symbols]

[0066] 10 Vehicle, 11 Powertrain, 12 Motor, 13 Battery, 14 Outside sensor, 15 Notification device, 16 Electronic control unit (ECU, display control unit), 21 Communication interface, 22 Memory, 23 Processor, 31 Mode setting unit, 32 Determination unit, 33 Prediction unit, 34 Condition setting unit, 35 Notification processing unit, 36 Driving control unit

Claims

1. a determination unit that determines whether the state of the vehicle battery satisfies a predetermined limiting condition; a notification processing unit that notifies a driver of the vehicle via a notification device provided in the vehicle of an output limitation warning that limits the output of a motor mounted in the vehicle when the state of the battery satisfies the limitation condition; and a condition setting unit that sets the limiting condition to a first condition when an acceleration / deceleration control mode that controls acceleration / deceleration of the vehicle in accordance with a vehicle-to-vehicle distance between the vehicle and a preceding vehicle is not applied, and sets the limiting condition to a second condition that is stricter than the first condition when the acceleration / deceleration control mode is applied; A display control device having the above configuration.

2. a prediction unit that determines whether a prediction condition for predicting execution of an accelerator operation by the driver is satisfied based on the driving status of other vehicles driving around the vehicle, the distance between the other vehicles and the vehicle, or the behavior of the driver; The display control device according to claim 1 , wherein the condition setting unit sets the limiting condition to the first condition when the prediction condition is satisfied, even if the acceleration / deceleration control mode is set.

3. determining whether the condition of the vehicle battery satisfies a predetermined limiting condition; When the state of the battery satisfies the limiting condition, an output limit warning is issued to a driver of the vehicle via a notification device provided in the vehicle, the output of a motor mounted in the vehicle being limited; setting the restriction condition to a first condition when an acceleration / deceleration control mode for controlling acceleration / deceleration of the vehicle in accordance with the distance between the preceding vehicle and the vehicle is not applied; The limiting condition when the acceleration / deceleration control mode is applied is set to a second condition that is stricter than the first condition. A display control method comprising:

4. determining whether the condition of the vehicle battery satisfies a predetermined limiting condition; When the state of the battery satisfies the limiting condition, an output limit warning is issued to a driver of the vehicle via a notification device provided in the vehicle, the output of a motor mounted in the vehicle being limited; setting the restriction condition to a first condition when an acceleration / deceleration control mode for controlling acceleration / deceleration of the vehicle in accordance with the distance between the preceding vehicle and the vehicle is not applied; The limiting condition when the acceleration / deceleration control mode is applied is set to a second condition that is stricter than the first condition. A display control computer program that causes a processor mounted on the vehicle to execute the above.

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