Object detection device, vehicle, method of setting wave receiving period in object detection device, and method of setting detection sensitivity in object detection device
An object detection device according to the present disclosure, installed in a vehicle, includes a plurality of ranging sensors and each including a transmitter configured to transmit ultrasonic waves and a receiver configured to receive reflected waves of the ultrasonic waves transmitted by the transmitter and reflected by an object around the vehicle, and processing circuitry configured to detect the object around the vehicle based on the reflected waves received by the receiver during a wave receiving period until a predetermined period of time elapses from transmission of the ultrasonic waves by the transmitter. The processing circuitry is configured to acquire an imaged image imaged by an in-vehicle camera that images surroundings of the vehicle. The processing circuitry is configured to determine whether a specific object is contained based on the imaged image. The processing circuitry is configured to set the wave receiving period from a first wave receiving period to a second wave receiving period longer than the first wave receiving period when the specific object is determined to be contained in the imaged image.
1. An object detection device configured to be mounted on a vehicle, comprising:
a plurality of ranging sensors and each including a transmitter which, in operation, transmits ultrasonic waves, and a receiver which, in operation, receives reflected waves of the ultrasonic waves transmitted by the transmitter and reflected by an object around the vehicle, and
processing circuitry which, in operation, detects the object around the vehicle based on the reflected waves received by the receiver during a wave receiving period until a predetermined period of time elapses from transmission of the ultrasonic waves by the transmitter, wherein
the processing circuitry
acquires an imaged image imaged by an in-vehicle camera that images surroundings of the vehicle,
determines whether a specific object is contained based on the imaged image,
estimates a relative position of the specific object to the vehicle when the specific object is determined to be contained in the imaged image, and
sets the wave receiving period from a first wave receiving period to a second wave receiving period longer than the first wave receiving period for a first ranging sensor among the plurality of ranging sensors based on the estimated relative position of the specific object, and
the relative position includes direction information of the specific object relative to the vehicle, and
the processing circuitry which, in operation, selects the first ranging sensor among the plurality of ranging sensors based on the direction information and sets, to the second wave receiving period, the wave receiving period for the first ranging sensor.
2. The object detection device according to claim 1 , wherein
the relative position includes distance information of the specific object to the vehicle, and
the processing circuitry which, in operation, sets the second wave receiving period so that the specific object is contained in detection ranges of the ranging sensors based on the distance information.
3. The object detection device according to claim 1 , wherein
the processing circuitry which, in operation,
further generates a predicted trajectory of the vehicle, and
determines the relative position of the specific object to the vehicle based on a positional relation between the specific object and a point where the vehicle approaches the specific object among points on the generated predicted trajectory.
4. The object detection device according to claim 3 , wherein the processing circuitry which, in operation, generates the predicted trajectory based on position information, speed information, and steering information of the vehicle.
5. The object detection device according to claim 1 , wherein the processing circuitry which, in operation, estimates the relative position of the specific object based on distribution of feature points related to the specific object in the imaged image when the specific object is determined to be contained in the imaged image.
6. The object detection device according to claim 1 , wherein
the first ranging sensor is a corner sensor installed near a corner of the vehicle,
a second ranging sensor among the plurality of ranging sensors is a center sensor installed near a center of the vehicle, and
when the processing circuitry which, in operation, does not determine that the specific object is contained in the imaged image, the wave receiving period for the second ranging sensor is set to be longer than the wave receiving period for the first ranging sensor.
7. The object detection device according to claim 1 , wherein when no specific object is determined to be contained in the imaged image after the wave receiving period is set from the first wave receiving period to the second wave receiving period longer than the first wave receiving period, the processing circuitry which, in operation, sets the wave receiving period from the second wave receiving period to a third wave receiving period shorter than the second wave receiving period.
8. The object detection device according to claim 7 , wherein the processing circuitry which, in operation, sets, to the third wave receiving period, the wave receiving period for the first ranging sensor among the ranging sensors based on the estimated relative position of the specific object.
9. The object detection device according to claim 7 , wherein the third wave receiving period is the same period as the first wave receiving period.
10. The object detection device according to claim 1 , wherein the specific object is a pedestrian or a bicycle.
11. A vehicle comprising:
an in-vehicle camera which, in operation, images surroundings of the vehicle; and
an object detection device mounted on the vehicle and comprising:
a plurality of ranging sensors and each including a transmitter which, in operation, transmits ultrasonic waves, and a receiver which, in operation, receives reflected waves of the ultrasonic waves transmitted by the transmitter and reflected by an object around the vehicle, and
processing circuitry which, in operation, detects the object around the vehicle based on the reflected waves received by the receiver during a wave receiving period until a predetermined period of time elapses from transmission of the ultrasonic waves by the transmitter, wherein
the processing circuitry
acquires an imaged image imaged by the in-vehicle camera,
determines whether a specific object is contained based on the imaged image,
estimates a relative position of the specific object to the vehicle when the specific object is determined to be contained in the imaged image, and
sets the wave receiving period from a first wave receiving period to a second wave receiving period longer than the first wave receiving period for a first ranging sensor among the plurality of ranging sensors based on the estimated relative position of the specific object,
the relative position includes direction information of the specific object relative to the vehicle, and
the processing circuitry which, in operation, selects the first ranging sensor based on the direction information and sets, to the second wave receiving period, the wave receiving period for the first ranging sensor.
12. A method of setting a wave receiving period in an object detection device mounted on a vehicle and having a plurality of ranging sensors using ultrasonic waves, the method of setting the wave receiving period comprising:
acquiring an imaged image imaged by an in-vehicle camera that images surroundings of the vehicle;
determining that a specific object is contained based on the imaged image;
estimating a relative position of the specific object to the vehicle when the specific object is determined to be contained in the imaged image;
setting the wave receiving period from a first wave receiving period to a second wave receiving period longer than the first wave receiving period for a first ranging sensor among the plurality of ranging sensors based on the estimated relative position of the specific object, wherein the relative position includes direction information of the specific object relative to the vehicle, and
selecting the first ranging sensor among the plurality of ranging sensors based on the direction information; and
setting, to the second wave receiving period, the wave receiving period for the first ranging sensor.
13. The method of setting the wave receiving period in the object detection device according to claim 12 , wherein
the relative position includes distance information of the specific object to the vehicle,
the second wave receiving period is set on the first ranging sensor based on the distance information, and
the specific object is contained in detection ranges of the first ranging sensor.
14. The method of setting the wave receiving period in the object detection device according to claim 12 , further comprising:
generating a predicted trajectory of the vehicle; and
determining the relative position of the specific object to the vehicle based on a positional relation between the specific object and a point where the vehicle approaches the specific object among points on the generated predicted trajectory.
15. The method of setting the wave receiving period in the object detection device according to claim 12 , further comprising:
estimating the relative position of the specific object based on distribution of feature points related to the specific object in the imaged image when the specific object is determined to be contained in the imaged image.
16. The method of setting the wave receiving period in the object detection device according to claim 12 , wherein
the first ranging sensor is a corner sensor installed near a corner of the vehicle,
a second ranging sensor among the plurality of ranging sensors is a center sensor installed near a center of the vehicle, and
when the specific object is determined not to be contained in the imaged image, the wave receiving period for the second ranging sensor is set to be longer than the wave receiving period for the first ranging sensor.
17. The method of setting the wave receiving period in the object detection device according to claim 12 , further comprising:
when no specific object is determined to be contained in the imaged image after the wave receiving period is set from the first wave receiving period to the second wave receiving period, setting the wave receiving period from the second wave receiving period to a third wave receiving period shorter than the second wave receiving period.
18. The method of setting the wave receiving period in the object detection device according to claim 12 , wherein the specific object is a pedestrian or a bicycle.