Vehicle-use collision mitigation apparatus

1. A vehicle-use collision mitigation apparatus comprising:

a controller device, the controller device being configured to facilitate

detecting a distance to a forward obstacle existing ahead of a first vehicle on which said vehicle-use collision mitigation apparatus is mounted in a traveling direction of said first vehicle;

detecting a relative speed between said first vehicle and said forward obstacle;

calculating a TTC indicative of a time remaining before collision between said first vehicle and said forward obstacle on the basis of said distance and said reference speed;

alarming a driver of said first vehicle of presence of a risk of collision with said forward obstacle, when said TTC is shorter than a predetermined first time;

increasing a first braking force generated by a braking operation performed by said driver, when said TTC is shorter than a predetermined second time not longer than said predetermined first time; and

automatically generating a second braking force, when said TTC is shorter than a predetermined third time shorter than said predetermined first time;

said controller device is configured to make an alarm for a driver of a second vehicle following said first vehicle that said first vehicle may decelerate abruptly to avoid collision with said forward obstacle at a timing which is the same as, or before a timing at which said first braking force is increased, and which is before a timing at which said second braking force is automatically generated, wherein

said predetermined second time is arranged to be varied depending on said relative speed within a range not exceeding said first predetermined time.

2. A vehicle-use collision mitigation apparatus comprising:

a controller device, the controller device being configured to facilitate

detecting a distance to a forward obstacle existing ahead of a first vehicle on which said vehicle-use collision mitigation apparatus is mounted in a traveling direction of said first vehicle;

detecting a relative speed between said first vehicle and said forward obstacle;

calculating a TTC indicative of a time remaining before collision between said first vehicle and said forward obstacle on the basis of said distance and said reference speed;

alarming a driver of said first vehicle of presence of a risk of collision with said forward obstacle, when said TTC is shorter than a predetermined first time;

increasing a first braking force generated by a braking operation performed by said driver, when said TTC is shorter than a predetermined second time not longer than said predetermined first time; and

automatically generating a second braking force, when said TTC is shorter than a predetermined third time shorter than said predetermined first time;

said controller device is configured to make an alarm for a driver of a second vehicle following said first vehicle that said first vehicle may decelerate abruptly to avoid collision with said forward obstacle at a timing which is the same as, or before a timing at which said first braking force is increased, and which is before a timing at which said second braking force is automatically generated, wherein

said controller device is configured to set a braking apparatus of said first vehicle to a standby state at a timing when said TTC becomes equal to or shorter than said second predetermined time, so that said first braking force is generated immediately when said driver of said first vehicle performs said braking operation.

3. A vehicle-use collision mitigation apparatus comprising:

a controller device, the controller device being configured to facilitate

detecting a distance to a forward obstacle existing ahead of a first vehicle on which said vehicle-use collision mitigation apparatus is mounted in a traveling direction of said first vehicle;

detecting a relative speed between said first vehicle and said forward obstacle;

calculating a TTC indicative of a time remaining before collision between said first vehicle and said forward obstacle on the basis of said distance and said reference speed;

alarming a driver of said first vehicle of presence of a risk of collision with said forward obstacle, when said TTC is shorter than a predetermined first time;

increasing a first braking force generated by a braking operation performed by said driver, when said TTC is shorter than a predetermined second time not longer than said predetermined first time; and

automatically generating a second braking force, when said TTC is shorter than a predetermined third time shorter than said predetermined first time;

said controller device is configured to make an alarm for a driver of a second vehicle following said first vehicle that said first vehicle may decelerate abruptly to avoid collision with said forward obstacle at a timing which is the same as, or before a timing at which said first braking force is increased, and which is before a timing at which said second braking force is automatically generated, wherein

the controller device is configured to set the predetermined second time such that it is shorter than the predetermined first time, when the relative speed is 0,

the controller device is configured to set the predetermined second time to increase with an increase of the relative speed within a range not exceeding the predetermined first time.

4. A computer-implemented method, implemented in a vehicle-use collision mitigation apparatus, for performing vehicle-use collision mitigation, comprising:

in a vehicle-use collision mitigation apparatus, detecting a distance to a forward obstacle existing ahead of a first vehicle on which said vehicle-use collision mitigation apparatus is mounted in a traveling direction of said first vehicle;

in said vehicle-use collision mitigation apparatus, detecting a relative speed between said first vehicle and said forward obstacle;

in said vehicle-use collision mitigation apparatus, calculating a TTC indicative of a time remaining before collision between said first vehicle and said forward obstacle on the basis of said distance and said reference speed;

in said vehicle-use collision mitigation apparatus, alarming a driver of said first vehicle of presence of a risk of collision with said forward obstacle, when said TTC is shorter than a predetermined first time;

in said vehicle-use collision mitigation apparatus, increasing a first braking force generated by a braking operation performed by said driver, when said TTC is shorter than a predetermined second time not longer than said predetermined first time; and

in said vehicle-use collision mitigation apparatus, automatically generating a second braking force, when said TTC is shorter than a predetermined third time shorter than said predetermined first time;

said vehicle-use collision mitigation apparatus makes an alarm for a driver of a second vehicle following said first vehicle that said first vehicle may decelerate abruptly to avoid collision with said forward obstacle at a timing which is the same as, or before a timing at which said first braking force is increased, and which is before a timing at which said second braking force is automatically generated, wherein

said predetermined second time being varied depending on said relative speed within a range not exceeding said first predetermined time.

5. A computer-implemented method, implemented in a vehicle-use collision mitigation apparatus, for performing vehicle-use collision mitigation, comprising:

in a vehicle-use collision mitigation apparatus, detecting a distance to a forward obstacle existing ahead of a first vehicle on which said vehicle-use collision mitigation apparatus is mounted in a traveling direction of said first vehicle;

in said vehicle-use collision mitigation apparatus, detecting a relative speed between said first vehicle and said forward obstacle;

in said vehicle-use collision mitigation apparatus, calculating a TTC indicative of a time remaining before collision between said first vehicle and said forward obstacle on the basis of said distance and said reference speed;

in said vehicle-use collision mitigation apparatus, alarming a driver of said first vehicle of presence of a risk of collision with said forward obstacle, when said TTC is shorter than a predetermined first time;

in said vehicle-use collision mitigation apparatus, increasing a first braking force generated by a braking operation performed by said driver, when said TTC is shorter than a predetermined second time not longer than said predetermined first time;

in said vehicle-use collision mitigation apparatus, automatically generating a second braking force, when said TTC is shorter than a predetermined third time shorter than said predetermined first time;

said vehicle-use collision mitigation apparatus makes an alarm for a driver of a second vehicle following said first vehicle that said first vehicle may decelerate abruptly to avoid collision with said forward obstacle at a timing which is the same as, or before a timing at which said first braking force is increased, and which is before a timing at which said second braking force is automatically generated; and

setting a braking apparatus of said first vehicle to a standby state at a timing when said ITC becomes equal to or shorter than said second predetermined time, so that said first braking force is generated immediately when said driver of said first vehicle performs said braking operation.

6. A computer-implemented method, implemented in a vehicle-use collision mitigation apparatus, for performing vehicle-use collision mitigation, comprising:

in a vehicle-use collision mitigation apparatus, detecting a distance to a forward obstacle existing ahead of a first vehicle on which said vehicle-use collision mitigation apparatus is mounted in a traveling direction of said first vehicle;

in said vehicle-use collision mitigation apparatus, detecting a relative speed between said first vehicle and said forward obstacle;

in said vehicle-use collision mitigation apparatus, calculating a TTC indicative of a time remaining before collision between said first vehicle and said forward obstacle on the basis of said distance and said reference speed;

in said vehicle-use collision mitigation apparatus, alarming a driver of said first vehicle of presence of a risk of collision with said forward obstacle, when said TTC is shorter than a predetermined first time;

in said vehicle-use collision mitigation apparatus, increasing a first braking force generated by a braking operation performed by said driver, when said TTC is shorter than a predetermined second time not longer than said predetermined first time; and

in said vehicle-use collision mitigation apparatus, automatically generating a second braking force, when said TTC is shorter than a predetermined third time shorter than said predetermined first time;

said vehicle-use collision mitigation apparatus makes an alarm for a driver of a second vehicle following said first vehicle that said first vehicle may decelerate abruptly to avoid collision with said forward obstacle at a timing which is the same as, or before a timing at which said first braking force is increased, and which is before a timing at which said second braking force is automatically generated, wherein

the predetermined second time being set such that it is shorter than the predetermined first time, when the relative speed is 0,

the predetermined second time being set to increase with an increase of the relative speed within a range not exceeding the predetermined first time.