Forward monitoring system
As a front monitoring system of a vehicle with strict restrictions on device arrangement, in a case where one or a plurality of external sensors are installed, an exit wave emitted from the external sensors and reflected by a structural object inside the vehicle is prevented from re-entering the external sensor, and erroneous detection of an object is suppressed. As a front monitoring system therefor, an external sensor that is mounted inside a vehicle, emits an exit wave toward a front of the vehicle, and acquires a reflected wave entering the external sensor as a detection signal, and a removing means that removes the exit wave emitted by the external sensor and incident on a structural object installed inside the vehicle in a specific direction, particularly at an incident angle larger than a predetermined angle are provided.
1 . A front monitoring system comprising:
an external sensor that is mounted inside a vehicle, emits an exit wave toward a front of the vehicle, and acquires a reflected wave entering the external sensor as a detection signal; and
a removing means that removes the exit wave emitted by the external sensor and incident on a structural object installed inside the vehicle in a specific direction,
wherein the removing means removes the exit wave emitted by the external sensor and entering the structural object at an incident angle larger than a predetermined angle,
wherein the external sensor includes a first external sensor and a second external sensor, and
the external sensor that emits the exit wave to be removed by the removing means is the first external sensor or the second external sensor, and
wherein the removing means is configured by software executed by a processing device included in the front monitoring system, and the software causes the processing device to execute:
a first step of acquiring the detection signal from the first or second external sensor that has emitted the exit wave; and
a second step of excluding, from the detection signal acquired in the first step, the detection signal incident on the second or first external sensor at larger than or equal to a minimum incident angle that is a minimum value of an incident angle when the exit wave is reflected by the structural object and is incident on the second or first external sensor, and holding the detection signal incident on the second or first external sensor at an angle smaller than the minimum incident angle, and
wherein the incident angle is an angle formed by the incident direction and a normal line of a boundary surface.
2 . The front monitoring system according to claim 1 , wherein the minimum incident angle is calculated based on at least geometric arrangement of the first external sensor, the second external sensor, and the structural object.
3 . The front monitoring system according to claim 1 , wherein the software causes the processing device to execute a third step of excluding, from the detection signal excluded in the second step, the detection signal incident on the second or first external sensor at smaller than or equal to a maximum incident angle that is a maximum value of the incident angle when the exit wave is reflected by the structural object and is incident on the second or first external sensor, as it is, and holding the detection signal incident on the second or first external sensor at an incident angle larger than the maximum incident angle.
4 . The front monitoring system according to claim 3 , wherein the maximum incident angle is calculated based on at least geometric arrangement of the first external sensor, the second external sensor, and the structural object.
5 . The front monitoring system according to claim 1 , wherein the software causes the processing device to execute:
a third step of acquiring a first detection signal from the second or first external sensor in a case where the first or second external sensor is emitting the exit wave;
a fourth step of acquiring a second detection signal from the second or first external sensor in a case where the first or second external sensor is not emitting the exit wave;
a fifth step of calculating a third detection signal by excluding the second detection signal from the first detection signal;
a sixth step of calculating, from the third detection signal, a minimum incident angle that is a minimum value of an incident angle of the exit wave incident on the second or first external sensor, and a maximum incident angle that is a maximum value of an incident angle of the exit wave incident on the second or first external sensor; and
a seventh step of excluding, from the first detection signal, the first detection signal incident on the second or first external sensor at an incident angle of larger than or equal to the minimum incident angle and smaller than or equal to the maximum incident angle, and outputting the first detection signal.
6 . The front monitoring system according to claim 1 , wherein the software causes the processing device to execute:
a third step of acquiring a first detection signal from the second or first external sensor in a case where the first or second external sensor is emitting the exit wave;
a fourth step of acquiring a second detection signal from the second or first external sensor in a case where the first or second external sensor is not emitting the exit wave;
a fifth step of calculating a third detection signal by excluding the second detection signal from the first detection signal;
a sixth step of calculating a direction in which the exit wave corresponding to the third detection signal is incident on the second or first external sensor as an excluding direction; and
a seventh step of excluding the first detection signal entering from the excluding direction from the first detection signal and outputting the first detection signal.
7 . The front monitoring system according to claim 2 , wherein the software causes the processing device to execute a third step of excluding, from the detection signal excluded in the second step, the detection signal incident on the second or first external sensor at smaller than or equal to a maximum incident angle that is a maximum value of an incident angle when the exit wave is reflected by the structural object and is incident on the second or first external sensor, as it is, and holding the detection signal incident on the second or first external sensor at an incident angle larger than the maximum incident angle.
8 . The front monitoring system according to claim 7 , wherein the maximum incident angle is calculated based on at least geometric arrangement of the first external sensor, the second external sensor, and the structural object.