Travel control apparatus, vehicle, travel control method, and non-transitory computer-readable storage medium

1. A travel control apparatus comprising:

a recognition unit configured to recognize a division line of a road on which a self-vehicle is traveling; and

a control unit configured to execute lane maintenance control to perform lane maintenance of the self-vehicle based on a recognition result of the division line by the recognition unit,

wherein if the recognition unit has become unable to recognize the division line in a case in which a first control state for executing the lane maintenance control is set, the control unit will allow preceding vehicle following control, for following a preceding vehicle of the self-vehicle, to be executed after switching the lane maintenance control to manual driving, based on a fact that a condition related to an elapsed time or a traveled distance since the division line could not be recognized has been satisfied, and

the control unit notifies a driver that the preceding vehicle following control can be executed after the condition is satisfied.

2. The apparatus according to claim 1 , wherein the first control state is a state for executing the lane maintenance control without issuance of a steering wheel gripping request.

3. The apparatus according to claim 2 , further comprising:

an obtainment unit configured to obtain map information of a periphery of the self-vehicle,

wherein the first control state is a control state in which the recognition result of the division line by the recognition unit and the map information obtained by the obtainment unit have been matched.

4. The apparatus according to claim 2 , wherein in a case in which a second control state for executing the lane maintenance control with issuance of a steering wheel gripping request is set, the control unit will execute the preceding vehicle following control without switching to the manual driving even in a case in which the recognition unit has become unable to recognize the division line.

5. The apparatus according to claim 2 , wherein in a case in which a second control state for executing the lane maintenance control with the issuance of the steering wheel gripping request is set, the control unit will execute the preceding vehicle following control regardless of the condition when the recognition unit has become unable to recognize the division line.

6. The apparatus according to claim 2 , wherein in a case in which a driver makes a request to execute the preceding vehicle following control, the control unit will execute the preceding vehicle following control even if the condition related to one of the elapsed time and the traveled distance is not yet satisfied.

7. The apparatus according to claim 1 , wherein if the recognition unit has become unable to recognize the division line in the case in which the first control state for executing the lane maintenance control is set, the control unit will maintain the manual driving during the condition is not satisfied.

8. A travel control apparatus comprising:

a recognition unit configured to recognize a division line of a road on which a self-vehicle is traveling; and

a control unit configured to execute lane maintenance control to perform lane maintenance of the self-vehicle based on a recognition result of the division line by the recognition unit,

wherein in a case in which a first control state for executing the lane maintenance control without issuance of a steering wheel gripping request is set, the control unit will switch the lane maintenance control to manual driving when the recognition unit has become unable to recognize the division line, and the control unit notifies a driver that preceding vehicle following control can be executed after a condition related to an elapsed time or a traveled distance since the division line could not be recognized is satisfied, and

in a case in which a second control state for executing the lane maintenance control with the issuance of the steering wheel gripping request is set, the control unit will switch from the lane maintenance control to the preceding vehicle following control, for following a preceding vehicle of the self-vehicle, when the recognition unit has become unable to recognize the division line.

9. A vehicle comprising a travel control apparatus defined in claim 1 .

10. A travel control method executed by a travel control apparatus comprising:

recognizing a division line of a road on which a self-vehicle is traveling;

performing control, in a case in which lane maintenance control for performing lane maintenance of the self-vehicle based on the recognition result of the division line in the recognizing is executed and the division line has become unable to be recognized in the recognizing, to allow preceding vehicle following control, for following a preceding vehicle of the self-vehicle, to be executed, after the lane maintenance control is switched to manual driving, based on a fact that a condition related to one of an elapsed time and a traveled distance since the division line has become unable to be recognized has been satisfied; and

notifying a driver that the preceding vehicle following control can be executed after the condition is satisfied.

11. A non-transitory computer-readable storage medium storing a program for causing a computer to function as each unit of

a recognition unit configured to recognize a division line of a road on which a self-vehicle is traveling; and

a control unit configured to perform control, in a case in which lane maintenance control for performing lane maintenance of the self-vehicle based on the recognition result of the division line by the recognition unit is executed and the recognition unit has become unable to recognize the division line, to allow preceding vehicle following control, for following a preceding vehicle of the self-vehicle, to be executed, after the lane maintenance control is switched to manual driving, based on a fact that a condition related to one of an elapsed time and a traveled distance since the division line has become unable to be recognized has been satisfied,

wherein the control unit notifies a driver that the preceding vehicle following control can be executed after the condition is satisfied.