JP7770830B2 - Driving control device - Google Patents

Description

The present invention relates to a cruise control device .

For example, Patent Document 1 below describes a control device that switches to coasting during cruise control. This device determines when to transition to coasting and when to end coasting based on the inter-vehicle time, which is the time it takes for the vehicle to travel the distance between itself and the preceding vehicle.

JP 2018-34597 A

However, drivers can express their intentions regarding driving, such as changing lanes, within the scope of not overriding cruise control. When such intentions are expressed, the appropriateness of coasting may change in light of the user's intentions. However, if the transition to coasting and the end of coasting are determined based on the time gap, as in the above-mentioned device, there is a risk that appropriate measures based on the situation may be delayed.

The means for solving the above problems and their effects will be described below.
The driving control device executes a coasting process, a cruising process, an operation input acquisition process (S92, S98, S102, S110), and a switching process (S96, S108), in which the coasting process is a process for coasting the vehicle, the cruising process is a process for controlling the speed of the vehicle to a set vehicle speed while prioritizing satisfaction of a predetermined condition, the predetermined condition being a condition for maintaining a distance from a preceding vehicle within a predetermined range in front of the vehicle, the operation input acquisition process is a process for acquiring an operation input by the driver of the vehicle to a predetermined operation unit (50, 50a, 70), the predetermined operation unit being an operation unit through which the driver expresses his or her intentions and which does not cause an override to the cruising process when it is assumed that the cruising process is being executed, and the switching process is a process for switching from one of the two processes, the coasting process and the cruising process, to the other, triggered by the operation input being acquired by the operation input acquisition process.

In the above configuration, switching from one of the two processes, coasting processing and cruising processing, to the other is performed in response to an operation input to a specified operation unit. This allows for rapid switching when the driver's intention to switch from one of the above processes to the other is appropriate.

1 is a diagram illustrating a configuration of a cruise control system according to an embodiment. 3 is a flowchart showing a procedure of a process executed by a control device according to the embodiment. 3 is a flowchart showing a procedure of a process executed by a control device according to the embodiment. 3 is a flowchart showing a procedure of a process executed by a control device according to the embodiment. 3 is a flowchart showing a procedure of a process executed by a control device according to the embodiment. 10A to 10D are diagrams for explaining the operation of the embodiment.

Hereinafter, an embodiment will be described with reference to the drawings.
FIG. 1 shows a device mounted on a vehicle in this embodiment. As shown in FIG. 1, an optical sensor 10 emits laser light, such as near-infrared light. The optical sensor 10 generates distance measurement point data based on receiving reflected laser light. The distance measurement point data indicates a distance variable indicating the distance between the object that reflected the laser light and the vehicle, a direction variable indicating the direction in which the laser light is emitted, and an intensity variable indicating the reflection intensity of the reflected object. This can be achieved, for example, by a TOF (Time of Flight) method. However, the distance measurement point data may be generated using an FMCW (Frequency Modulated Continuous Wave) method instead of the TOF method. In this case, the distance measurement point data may include a speed variable indicating the relative speed of the object that reflected the laser light.

The optical sensor 10 periodically scans the irradiation direction of the laser light in the horizontal and vertical directions, and outputs ranging point cloud data Drpc, which is a collection of the obtained ranging point data.
The LIDARECU 12 executes a process for recognizing an object that reflects laser light based on the ranging point cloud data Drpc. The recognition process may be executed, for example, according to the following steps: First, a clustering process is executed on the ranging point cloud data Drpc. Next, feature amounts are extracted from a set of ranging point data identified as a single object by the clustering process. Next, the extracted feature amounts are input to an identification model that determines whether or not the object is a specified object. Alternatively, instead of the process including these steps, the ranging point cloud data Drpc may be directly input to a deep learning model to recognize the object.

The camera 20 outputs image data Dpo of the outside of the vehicle VC. The image ECU 22 performs recognition processing of objects around the vehicle based on the image data Dpo, which is data related to the image captured by the camera 20.

The ADASECU 30 executes processing to control the driving of the vehicle VC. When executing processing to control driving, the ADASECU 30 receives the recognition results from the LIDARECU 12 and the image ECU 22 via the local network 40. The ADASECU 30 also executes cruise control and other operations in response to input operations to the cruise system interface 50. The cruise system interface 50 is an interface that allows input operations such as instructions on whether or not to execute cruise control and instructions on the set vehicle speed SPD* for cruise driving processing. When executing cruise control, the ADASECU 30 also operates the drive system 60, braking system 62, steering system 64, and display 66.

The drivetrain 60 includes at least one of the two thrust generating devices for the vehicle: an internal combustion engine and a rotating electric machine. The drivetrain 60 may also include a drive control device that controls the internal combustion engine and the rotating electric machine. In this case, "the ADASECU 30 operates the drivetrain 60" means that the ADASECU 30 outputs a command signal to the drive control device.

The braking system 62 includes at least one of two devices: a device that uses friction to slow down the rotation of the wheels, and a device that converts the power of the wheels into electrical energy to slow down the rotation of the wheels. The device that slows down the rotation of the wheels by converting it into electrical energy may be shared with the rotating electric machine of the drive system. The braking system may also include a braking control device that controls the device that slows down the rotation of the wheels. In this case, "the ADASECU 30 operates the braking system 62" means that the ADASECU 30 outputs a command signal to the braking control device.

The steering system 64 includes a steering actuator that steers the steered wheels. The steering system 64 may also include a steering control device that operates the steering actuator. In this case, "the ADASECU 30 operates the steering system 64" means that the ADASECU 30 outputs a command signal to the steering control device.

The display 66 is a device that displays the set vehicle speed SPD* in cruise control and the like as information that can be seen by the driver.
The ADASECU 30 refers to a turn signal Win indicating the operation state of the turn signal 70 and a steering torque Trq detected by a steering torque sensor 72. The ADASECU 30 also refers to a vehicle speed SPD detected by a vehicle speed sensor 74 and a longitudinal acceleration Gx detected by an acceleration sensor 76. The ADASECU 30 also refers to an accelerator operation amount ACCP, which is the amount of depression of the accelerator pedal, detected by an accelerator sensor 78, and a brake operation amount Brk, which is the amount of depression of the brake pedal, detected by a brake sensor 80.

More specifically, the ADASECU 30 includes a CPU 32, a storage device 34, and peripheral circuits 36. The peripheral circuits 36 include a circuit that generates a clock signal that regulates internal operation, a power supply circuit, a reset circuit, and the like. The ADASECU 30 performs cruising processing and other operations by having the CPU 32 execute a driving control program 34a stored in the storage device 34.

In this embodiment, when cruise control is instructed by an input operation to the cruise system interface 50, the CPU 32 executes a cruise driving process or a coasting driving process. The cruise driving process is a process for controlling the vehicle speed SPD to the set vehicle speed SPD*. However, if a preceding vehicle is present within a specified range of the lane in which the host vehicle is traveling, the CPU 32 prioritizes control to maintain the inter-vehicle distance from the preceding vehicle within a specified range. Furthermore, if there is no preceding vehicle within a specified range of the lane in which the host vehicle is traveling, the CPU 32 executes a coasting driving process within a range in which the difference between the vehicle speed SPD and the set vehicle speed SPD* is equal to or less than a specified value. Incidentally, the CPU 32 recognizes the preceding vehicle based on the recognition results from the LIDARECU 12 and the image ECU 22, respectively.

The coasting process is a process in which power is not applied from the vehicle's thrust generating device to the drive wheels. For example, if the drivetrain 60 includes an internal combustion engine and a transmission as the thrust generating device, the process may be a neutral state in which power transmission between the internal combustion engine and the drive wheels is interrupted. Furthermore, if the drivetrain 60 includes a rotating electric machine as the thrust generating device, the process may be a process in which the torque command value of the rotating electric machine is set to zero. Note that, in cases such as when the drivetrain 60 includes an internal combustion engine and a rotating electric machine as the thrust generating device, it is not essential that the thrust generating device not generate power during the coasting process. In other words, in such cases, the driving force of the internal combustion engine may be converted into power generated by the rotating electric machine, so that the proportion of the driving force of the internal combustion engine transmitted to the drive wheels is zero.

The processes executed by the ADASECU 30 will be explained below in the following order: "Process related to determining whether cruise control can be performed," "Process related to setting the set vehicle speed SPD* for cruise driving processing," and "Process related to switching between cruise driving processing and coasting driving processing." In particular, in this embodiment, for ease of explanation, the "process related to switching between cruise driving processing and coasting driving processing" is divided into a switching process based on the inter-vehicle distance, etc., and a switching process based on the driver's intention.

"Processing for determining whether cruise control can be performed"
2 shows the procedure for determining whether cruise control can be performed. The process shown in FIG. 2 is realized by the CPU 32 repeatedly executing the cruise control program 34a, for example, at a predetermined interval. In the following, the step numbers of each process are represented by numbers preceded by the letter "S."

In the series of processes shown in FIG. 2 , the CPU 32 first determines whether the ACC selector switch of the cruise system interface 50 is in the ON state (S10). The ACC selector switch is turned ON to instruct cruise control. If the CPU 32 determines that the ACC selector switch is in the ON state (S10: YES), it then determines whether the cruise control flag Facc is "1" (S12). The cruise control flag Facc is set to "1" when either the cruising process or the coasting process is being executed, and is set to "0" when neither is being executed. If the CPU 32 determines that the cruise control flag Facc is "0" (S12: NO), it determines whether neither the accelerator pedal nor the brake pedal is being operated (S18). This process determines whether the conditions for executing cruise control are met. That is, in this embodiment, the condition for executing cruise control is that the logical AND of the ACC selector switch being in the ON state and the absence of a driver override is true. Here, the override is either the operation of the accelerator pedal or the operation of the brake pedal. If the CPU 32 determines that neither is occurring (S18: YES), it assigns "1" to the cruise control flag Facc (S20).

On the other hand, if the CPU 32 determines that the cruise control flag Facc is "1" (S12: YES), it determines whether the logical sum of the accelerator pedal operation and the brake pedal operation is true (S14). This process determines whether an override has occurred while cruise control is being executed. If the CPU 32 determines that the logical sum is true (S14: YES), it assigns "0" to the cruise control flag Facc (S16).

The CPU 32 temporarily ends the series of processes shown in FIG. 2 when it completes the processes of S16 and S20 or when it makes a negative determination in the processes of S10, S14, and S18.
"Processing related to setting of cruise speed SPD*"
3 shows a process for setting the set vehicle speed SPD* for the cruise control process. The process shown in FIG. 3 is realized by the CPU 32 repeatedly executing the cruise control program 34a, for example, at predetermined intervals.

In the series of processes shown in FIG. 3, the CPU 32 determines whether the cruise control flag Facc is "1" (S30). If the CPU 32 determines that the flag is "1" (S30: YES), it determines whether the change flag Fmp is "1" (S32). The change flag Fmp is "1" when a process to change the set vehicle speed SPD* is being executed, and is "0" when the process is not being executed.

If the CPU 32 determines that the value is "0" (S32: NO), it determines whether the logical sum of the operation to increase the set vehicle speed SPD* and the operation to decrease the set vehicle speed SPD* performed by operating the cruise system interface 50 is true (S34). In FIG. 3, an operation to increase the set vehicle speed SPD* is referred to as an "UP operation," while an operation to decrease the set vehicle speed SPD* is referred to as a "DOWN operation." Note that the operation to increase the set vehicle speed SPD* may be, for example, a process in which the set vehicle speed SPD* is increased by a predetermined speed, such as 1 km/h, each time a predetermined lever is tapped. Hereinafter, this operation will be referred to as a tap-up operation. Note that the operation to increase the set vehicle speed SPD* is not limited to a tap-up operation. For example, it may include an operation of pressing and holding a predetermined lever. In this case, the CPU 32 may continuously increase the set vehicle speed SPD*.

The operation to reduce the set vehicle speed SPD* may be a process in which the set vehicle speed SPD* is reduced by a predetermined speed, such as 1 km/h, each time a predetermined lever is tapped. Hereinafter, this operation will be referred to as a tap-down operation. Note that the operation to reduce the set vehicle speed SPD* is not limited to a tap-down operation. For example, it may also include an operation of pressing and holding a predetermined lever. In this case, the CPU 32 may continuously reduce the set vehicle speed SPD*.

If the CPU 32 determines that the logical sum is true (S34: YES), it assigns "1" to the change flag Fmp (S36). The CPU 32 then operates the display 66 to update the set vehicle speed SPD* (S38). Here, for example, if a tap-up operation is performed, the CPU 32 simply updates the set vehicle speed SPD* to one that is increased by a predetermined speed (S38). Furthermore, if a predetermined lever is pressed and held to instruct an increase in the set vehicle speed SPD*, the displayed set vehicle speed SPD* can be continuously updated.

On the other hand, if the CPU 32 determines that the change flag Fmp is "1" (S32: YES), it determines whether an operation to increase or decrease the set vehicle speed SPD* has been performed (S40). This process is intended to deal with the continuous execution of operations to change the set vehicle speed SPD*, such as the driver performing a tap-up operation twice to increase the set vehicle speed SPD* by twice the predetermined speed. If the CPU 32 determines that an operation is being performed continuously (S40: NO), it proceeds to processing of S38.

In contrast, if the CPU 32 determines that no operation has been performed (S40: YES), it determines whether a predetermined time has passed since the operation ceased (S42). This process determines whether the driver has no intention of further changing the set vehicle speed SPD*. If the CPU 32 determines that the predetermined time has passed (S42: YES), it finalizes the set vehicle speed SPD* (S44). In other words, the CPU 32 begins processing to operate the drivetrain 60, etc., using the updated set vehicle speed SPD* as an input, such as by feedback-controlling the vehicle speed SPD to the updated set vehicle speed SPD*.

The CPU 32 temporarily ends the series of processes shown in FIG. 3 when it completes the processes of S38 and S44 or when it makes a negative determination in the processes of S30, S34, and S42.
"Processing for switching between cruising and coasting"
1. Switching Process According to Inter-Vehicle Distance, etc. Fig. 4 shows the procedure for switching process according to inter-vehicle distance, etc. The process shown in Fig. 4 is realized by the CPU 32 repeatedly executing the driving control program 34a, for example, at a predetermined interval.

In the series of processes shown in FIG. 4, the CPU 32 first determines whether the cruise control flag Facc is "1" (S50). If the CPU 32 determines that the cruise control flag Facc is "1" (S50: YES), it determines whether the vehicle is in coasting mode (S52). If the CPU 32 determines that the vehicle is in coasting mode (S52: YES), it determines whether the inter-vehicle time is smaller than the threshold value t1 (S70). The inter-vehicle time is the time required for the host vehicle to reach the current position of the preceding vehicle in the lane in which the host vehicle is traveling. The inter-vehicle time is calculated by the CPU 32 based on the vehicle speed SPD. This process determines whether braking force should be applied to the host vehicle in order to safely drive the host vehicle in a situation where a preceding vehicle is present. The threshold value t1 is set to a short inter-vehicle time that should require braking force to be applied to the host vehicle.

If the CPU 32 determines that the vehicle speed SPD is greater than or equal to the threshold value t1 (S70: NO), it determines whether the vehicle speed SPD is less than or equal to the set vehicle speed SPD* plus a predetermined amount α (S72). The predetermined amount α is the upper limit of the amount by which the vehicle speed SPD exceeds the set vehicle speed SPD* when the vehicle speed SPD is controlled in accordance with the set vehicle speed SPD*. If the CPU 32 determines that the vehicle speed SPD is less than or equal to the value obtained by adding the predetermined amount α (S72: YES), it determines whether the vehicle speed SPD is greater than or equal to the value obtained by subtracting a predetermined amount β from the set vehicle speed SPD* (S74). The predetermined amount β is the lower limit of the amount by which the vehicle speed SPD falls below the set vehicle speed SPD* when the vehicle speed SPD is controlled in accordance with the set vehicle speed SPD*.

If the CPU 32 determines that the longitudinal acceleration Gx is equal to or greater than the value obtained by subtracting the predetermined amount β (YES at S74), it determines whether the longitudinal acceleration Gx is equal to or greater than zero (S76). This process determines whether the vehicle is not decelerating despite coasting processing. On the other hand, if the CPU 32 determines that the longitudinal acceleration Gx is less than the value obtained by subtracting the predetermined amount β (NO at S74), it determines whether the inter-vehicle time is equal to or greater than threshold value t4 (S80). This process determines whether the distance to the preceding vehicle is excessively large. Threshold value t4 is set to a value greater than threshold value t1. Note that the preceding vehicle here is the vehicle targeted by the cruising process. In other words, it refers to vehicles located within a predetermined range ahead of the host vehicle in the lane in which the host vehicle is traveling. Therefore, it does not include vehicles located farther away than the predetermined range. If there is no preceding vehicle within the predetermined range, the CPU 32 makes a negative determination at S80.

When the CPU 32 makes a positive determination in the processing of S70, S76, or S80, or when the CPU 32 makes a negative determination in the processing of S72, the CPU 32 switches to the cruise driving mode (S78). That is, in the coasting driving mode, the CPU 32 switches to the cruise driving mode when any of the following conditions is met:

Condition (A): The inter-vehicle time is smaller than a threshold value t1.
Condition (A): The amount by which the vehicle speed SPD exceeds the set vehicle speed SPD* exceeds a predetermined amount α.

Condition (c): Vehicle speed SPD is equal to or greater than a value that is a predetermined amount β smaller than set vehicle speed SPD* and a predetermined amount α larger than set vehicle speed SPD*, and longitudinal acceleration Gx is equal to or greater than zero.

Condition (d): The logical product of the amount by which the vehicle speed SPD falls below the set vehicle speed SPD* exceeding a predetermined amount β and the time headway being equal to or greater than a threshold value t4 is true.
On the other hand, when the CPU 32 determines that the vehicle is in the cruise mode (S52: NO), it determines whether the braking force is greater than zero (S54). When the CPU 32 determines that the braking force is greater than zero (S54: YES), it determines whether the inter-vehicle time is equal to or greater than a threshold value t2 (S56). The threshold value t2 is set to a value greater than the threshold value t1 but smaller than the threshold value t4. This process determines whether the vehicle can be coasted by reducing the braking force of the vehicle. When the CPU 32 determines that the vehicle speed SPD is equal to or greater than the threshold value t2 (S56: YES), it determines whether the vehicle speed SPD is equal to or greater than a value obtained by subtracting a predetermined amount β from the set vehicle speed SPD* (S58). When the CPU 32 determines that the vehicle speed SPD is equal to or greater than the value obtained by subtracting the predetermined amount β (S58: YES), it determines whether the longitudinal acceleration Gx during coasting is negative (S60). This process determines whether the vehicle will decelerate due to coasting. This process can be implemented by estimating the inclination angle of the road surface on which the vehicle is traveling based on, for example, the power of the drive train and the longitudinal acceleration Gx.

On the other hand, if the CPU 32 determines that the time headway is less than the value obtained by subtracting the predetermined amount β (S58: NO), it determines whether the time headway is less than threshold value t4 (S62). Furthermore, if the CPU 32 determines that the braking force is equal to or less than zero (S54: NO), it determines whether the vehicle speed SPD is equal to or greater than the value obtained by subtracting the predetermined amount β from the set vehicle speed SPD* (S64). If the CPU 32 determines that the vehicle speed SPD is equal to or greater than the value obtained by subtracting the predetermined amount β (S64: YES), it proceeds to processing in S60. On the other hand, if the CPU 32 determines that the time headway is less than the value obtained by subtracting the predetermined amount β (S64: NO), it determines whether the time headway is less than threshold value t3 (S66). Threshold value t3 is greater than threshold value t2 but less than threshold value t4.

If the determinations in S60, S62, and S66 are affirmative, the CPU 32 switches to coasting mode (S68). That is, if any of the following conditions are met in cruise mode, the CPU 32 switches to coasting mode.

Condition (f): The vehicle speed SPD is equal to or greater than the set vehicle speed SPD* minus a predetermined amount β, and the longitudinal acceleration Gx during coasting is negative.
Condition (K): The condition is that the logical product of the braking force being positive, the vehicle speed SPD being less than the value obtained by subtracting a predetermined amount β from the set vehicle speed SPD*, and the inter-vehicle time being greater than or equal to threshold value t2 and less than threshold value t4 is true.

Condition (H): The logical product of the following conditions is true: braking force is zero or less; vehicle speed SPD is less than the set vehicle speed SPD* minus a predetermined amount β; and the time headway is less than threshold value t3.

The CPU 32 temporarily terminates the series of processes shown in FIG. 4 when it completes the processes of S68 and S78, or when it makes a negative determination in the processes of S50, S56, S60, S62, S66, S76, and S80.

2. Switching Process According to Driver's Intention The procedure for switching process according to driver's intention is shown in Fig. 5. The process shown in Fig. 5 is realized by the CPU 32 repeatedly executing the driving control program 34a, for example, at a predetermined interval.

In the series of processes shown in FIG. 5, the CPU 32 first determines whether the vehicle is in coasting mode (S90). If the CPU 32 determines that the vehicle is in coasting mode (S90: YES), it determines whether the turn signal 70 has been operated (S92). This process determines whether the driver intends to change lanes. If the CPU 32 determines that the turn signal 70 has been operated, it determines whether the lane adjacent to the lane the vehicle is traveling in and indicated by the turn signal 70 is an overtaking lane (S94). If the CPU 32 determines that the lane is an overtaking lane (S94: YES), it transitions to cruise mode (S96).

On the other hand, if the CPU 32 determines that the turn signal 70 has not been operated (S92: NO), it determines whether the cruise interface 50 has been operated to instruct an increase in the set vehicle speed SPD* (S98). If the CPU 32 determines that such an operation has been performed (S98: YES), it determines whether the vehicle speed SPD is lower than the set vehicle speed SPD* (S100). If the CPU 32 determines that the vehicle speed SPD is lower than the set vehicle speed SPD* (S100: YES), it proceeds to processing of S96.

On the other hand, if the CPU 32 determines that the vehicle is in cruise mode (S90: NO), it determines whether the turn signal 70 has been operated (S102). This process determines whether the driver intends to change lanes. If the CPU 32 determines that the turn signal 70 has been operated, it determines whether the lane adjacent to the lane in which the vehicle is traveling and indicated by the turn signal 70 is the driving lane (S104). If the CPU 32 determines that the lane is the driving lane (S104: YES), it determines whether the inter-vehicle time is greater than or equal to threshold value t1 and less than threshold value t3 (S106). If the CPU 32 determines that the inter-vehicle time is greater than or equal to threshold value t1 and less than threshold value t3 (S106: YES), it transitions to coasting mode (S108).

On the other hand, if the CPU 32 determines that the turn signal 70 has not been operated (S102: NO), it determines whether the cruise control interface 50 has been operated to instruct a decrease in the set vehicle speed SPD* (S110). If the CPU 32 determines that such an operation has been performed (S110: YES), it proceeds to processing of S108.

Note that the CPU 32 temporarily terminates the series of processes shown in Figure 5 when it completes the processes of S96 and S108, or when it makes a negative determination in the processes of S94, S98, S100, S104, S106, and S110.

Here, the operation and effects of this embodiment will be described.
6A illustrates an example in which the turn signal 70 is operated to indicate a lane change to an overtaking lane while the host vehicle VC(1) is traveling in the driving lane in the coasting mode. In this case, the CPU 32 switches from the coasting mode to the cruising mode. This quickly resolves the situation in which the vehicle decelerates.

In coasting mode, the host vehicle VC(1) generally tends to decelerate. On the other hand, when the driver changes lanes to an overtaking lane, there is a high possibility that the driver will want to accelerate the host vehicle VC(1). Therefore, if the coasting mode continues despite a lane change, a discrepancy will arise between the driver's intentions and the behavior of the host vehicle VC(1). For this reason, as illustrated in FIG. 4, if the coasting mode is switched to the cruise mode only based on the inter-vehicle time, etc., the driver may feel uncomfortable. In other words, in the process of FIG. 4, the host vehicle VC(1) switches to the coasting mode only if it is determined that conditions such as the vehicle speed SPD are met. In particular, as illustrated in FIG. 6(a), if a vehicle VC(2) is present ahead in the overtaking lane, the host vehicle VC(1) cannot switch to the cruise mode until it is determined that the inter-vehicle time condition with the vehicle VC(2) is met. For this reason, the switch to the cruise mode tends to be delayed.

Figure 6(b) illustrates an example in which the driver taps up the lever 50a of the cruise system interface 50 in coasting mode. In this case, the CPU 32 switches to cruise driving mode on the condition that the vehicle speed SPD is lower than the set vehicle speed SPD*. This allows for a prompt response to the driver's intention to accelerate. That is, as shown in Figure 3, even if a tap-up operation is performed, the set vehicle speed used for control is not determined until a predetermined time has elapsed after the operation. Therefore, if the processing of Figure 5 is not executed, switching to cruise driving mode will not occur until a predetermined period of time has elapsed after the tap-up operation is completed, and the processing of Figure 4 determines that the conditions for switching to cruise driving mode are met. This tends to delay switching to cruise driving mode.

Figure 6(c) illustrates an example in which, in cruise mode, the turn signal 70 is operated to indicate that the host vehicle VC(1) is changing lanes from the passing lane to the driving lane. In this case, the CPU 32 switches from cruise mode to coasting mode. This allows the energy utilization efficiency of the host vehicle VC(1) to be improved.

In other words, if switching to coasting mode is performed solely through the processing in Figure 4, switching to coasting mode will not occur until the inter-vehicle time condition and the vehicle speed SPD condition are met. As a result, there is a risk that switching to coasting mode will be delayed or the opportunity to execute coasting mode will be lost.

Figure 6(d) illustrates an example in which the driver taps down the lever 50a of the cruise interface 50 in cruise mode. In this case, the CPU 32 switches to coasting mode. This improves the energy utilization efficiency of the host vehicle VC(1).

According to the present embodiment described above, the following actions and effects can be further obtained.
(1) As shown in Figure 6(c), when a vehicle VC(2) is present ahead in the driving lane of the lane change destination, the CPU 32 switches to the coasting mode when the inter-vehicle time is equal to or greater than threshold value t1 and smaller than threshold value t3. In contrast, if the coasting mode is switched to even when the inter-vehicle time is less than threshold value t1, the inter-vehicle distance is deemed excessively short, and the CPU 32 switches back to the cruise mode to apply braking force to decelerate the host vehicle VC(1). Furthermore, if the coasting mode is switched to even when threshold value t3 is greater than or equal to threshold value t3, the host vehicle VC(1) will decelerate even though the inter-vehicle distance to the preceding vehicle VC(2) is excessively large, which may cause discomfort to the driver.

<Other embodiments>
This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

"About the lane change operation unit"
The lane change operation unit is not limited to the turn signal 70. For example, it may be a steering wheel. In this case, for example, the steering torque Trq detected by the steering torque sensor 72 may be used as an input to execute processing similar to that shown in FIG. 5. That is, for example, instead of the processing of S92 and S102, it may be determined whether the magnitude of the steering torque Trq is equal to or greater than a threshold value. Note that the processing of S94 and S104 may be executed based on the sign of the steering torque Trq.

However, it is not necessary to use only one of the turn signals 70 and the steering wheel as the lane change operation device. For example, both of them may be used as lane change operation devices.

"Regarding the specified operation section"
The predetermined operation unit that does not cause an override of the cruise driving process is not limited to being composed of both a lane change operation unit and a speed change operation unit. For example, it may be composed of only a lane change operation unit. Or, for example, it may be composed of only a speed change operation unit. Or, for example, instead of an operation unit that instructs acceleration and deceleration of the vehicle VC, the speed change operation unit may be composed of an operation unit that instructs acceleration of the vehicle VC but does not instruct deceleration.

"Cruise switching process when changing lanes"
In the above embodiment, the cruise control is always switched to when changing lanes into an overtaking lane. However, this is not limited to this. For example, if the distance between the vehicle and the preceding vehicle traveling in the overtaking lane is within a predetermined range, the coasting control may be continued. Here, the predetermined range may be set to a larger range as the vehicle speed SPD increases. This can suppress control hunting, which occurs when the coasting control is switched to by the process at S62 in FIG. 4 immediately after switching to the cruise control.

"About coasting switching processing when changing lanes"
In the above embodiment, when changing lanes to the driving lane, the coasting process is switched to if the inter-vehicle time is equal to or greater than threshold value t1 and smaller than threshold value t3. However, this is not limited to this. For example, if the inter-vehicle time is greater than threshold value t1, the coasting process may be switched to regardless of whether the inter-vehicle time is smaller than threshold value t3. This corresponds to not setting an upper limit to the predetermined range when switching to the coasting process when the inter-vehicle distance is within the predetermined range.

For example, if the logic is such that the system quickly switches to cruising mode and deceleration mode when the inter-vehicle time is equal to or less than threshold value t1, the system may switch to coasting mode when the inter-vehicle time is less than threshold value t3. This corresponds to not setting a lower limit for the specified range when switching to coasting mode when the inter-vehicle distance is within the specified range.

A threshold value t4 may be used in place of the threshold value t3.
Furthermore, it is not essential to switch to coasting mode when the inter-vehicle distance is within a predetermined range.

"Cruise switching process during ascent"
In the above embodiment, the cruise control is switched to when an instruction to increase the vehicle speed is issued and the vehicle speed SPD is lower than the set vehicle speed SPD*. However, this is not limited to this. For example, the process of S100 may be omitted. This allows for a quick response when the vehicle speed SPD becomes equal to or higher than the set vehicle speed SPD* due to the change in the set vehicle speed SPD*.

"About coasting switching process when the vehicle is lowered"
In the above embodiment, the coasting process is switched to when a command to reduce the vehicle speed is issued. However, this is not limited to this. For example, the condition may be that the inter-vehicle time is greater than the threshold value t1. In other words, the condition may be that the situation is not one in which intentional deceleration control is desirable to maintain the inter-vehicle distance.

"Regarding the processing in Figure 4"
While Figure 4 shows an example in which switching between the cruise mode and the coasting mode is performed based on the inter-vehicle time, this is not limiting. For example, switching may be performed based on a comparison of the inter-vehicle distance with a threshold value. Here, the threshold value may be variably set based on the vehicle speed SPD. In this case, the threshold value may be set to a higher value when the vehicle speed SPD is high than when it is low. Also, for example, the threshold value may be variably set according to the relative speed with the preceding vehicle. In this case, the threshold value may be set to a higher value when the relative speed is low than when it is high. Note that here, when the distance between the preceding vehicle and the subject vehicle decreases, the relative speed is considered negative.

"About driving control devices"
In the above embodiment, the ADASECU 30 as a driving control device receives the object recognition result obtained by performing clustering processing or the like on the ranging point cloud data Drpc by the LIDARECU 12. However, this is not limited to this. For example, the ADASECU 30 may execute the processing executed by the LIDARECU 12 in the above embodiment.

- In the above embodiment, the ADASECU 30 as a driving control device receives the object recognition results obtained by performing image recognition processing, etc. on the image data Dpo by the image ECU 22, but this is not limited to this. For example, the ADASECU 30 may also execute the processing executed by the image ECU 22 in the above embodiment.

- The driving control device is not limited to one equipped with a CPU 32 and a storage device 34 and executing software processing. For example, it may be equipped with a dedicated hardware circuit, such as an ASIC, that performs hardware processing on at least a portion of the software processing performed in the above embodiment. In other words, the execution device may have any of the following configurations (a) to (c): (a) A processing device that executes all of the above processing in accordance with a program, and a program storage device that stores the program. (b) A processing device and program storage device that execute part of the above processing in accordance with a program, and a dedicated hardware circuit that executes the remaining processing. (c) A dedicated hardware circuit that executes all of the above processing. Here, there may be multiple software execution devices equipped with a processing device and program storage device, and multiple dedicated hardware circuits.

"About Computers"
The computer is not limited to a single CPU 32 as illustrated in Fig. 1. Furthermore, it is not limited to a computer installed in a vehicle as illustrated in Fig. 1. For example, the process in Fig. 3 may be executed by a CPU installed in a driver's mobile terminal. In this case, the computer installed in the vehicle and a computer not installed in the vehicle communicate with each other and execute the driving control program 34a in cooperation.

"Others"
In the above embodiment, an example was described in which an object was recognized based on the ranging point cloud data Drpc output by the optical sensor 10 and the image data Dpo output by the camera 20, but this is not limiting. For example, ranging data output by a radar device such as a millimeter wave may also be taken into account. However, it is not essential to use so-called sensor fusion, which recognizes an object based on detection values from multiple sensors.

30...ADASECU
50a...lever

Claims (7)

Executes coasting processing, cruising processing, operation input acquisition processing (S92, S98, S102, S110), and switching processing (S96, S108),
The coasting process is a process for coasting the vehicle,
The vehicle includes a speed change operation unit (50a) that receives a command to change a set vehicle speed,
the cruising process is a process of controlling the speed of the vehicle to the set vehicle speed without coasting while prioritizing satisfaction of a predetermined condition,
the predetermined condition is a condition for maintaining a distance to a leading vehicle within a predetermined range when the leading vehicle is present within a specified range ahead of the vehicle,
the operation input acquisition process is a process of acquiring an operation input made by a driver of the vehicle to the speed change operation unit ,
The switching process is a process for switching to a coasting process when a reduction in the set vehicle speed is instructed by operation of the speed change operation unit while the cruising process is being executed. The cruise control device of claim 1, wherein the cruise control processing and the coasting processing are configured to be executed when the logical product of cruise control being instructed by the driver and no override by the driver is true. The vehicle is provided with a lane change operation unit (70) that is operated when changing the lane in which the vehicle is traveling,
The lane change cruise control process (S96) is executed.
3. A driving control device according to claim 1, wherein the lane change cruise switching process is a process for switching to the cruise driving process when it is predicted that the vehicle will change lanes to an overtaking lane by operating the lane change operation unit while the coasting driving process is being executed. The system is configured to execute a coasting switching process (S108) when changing lanes,
4. The driving control device according to claim 3, wherein the coasting switching process during lane change is a process for switching to the coasting process when it is predicted that the vehicle will change lanes to the driving lane by operating the lane change operation unit while the cruising process is being executed. The cruise control device of claim 4, wherein the coasting switching process during lane change is a process for switching to the coasting process when a preceding vehicle is traveling in the driving lane that is the predicted destination lane, provided that the inter-vehicle distance from the preceding vehicle is within a predetermined range. The system is configured to execute a cruise switching process during ascent (S96),
A driving control device as described in any one of claims 1 to 5, wherein the cruise switching process during ascent is a process for switching to the cruise driving process when an increase in the set vehicle speed is instructed by operation of the speed change operating unit while the coasting driving process is being executed. 7. The cruise control device according to claim 6 , wherein the ascending cruise switching process is a process for switching to the cruise driving process when an instruction to increase the set vehicle speed is given and the vehicle speed is less than the set vehicle speed.