Obstacle detection system with ultrasonic sensors located at either side of a bumper, having own beam axes at an angle deflected in a horizontal direction from a surface-normal direction of the bumper

An obstacle detection system, comprising:

• ultrasonic sensors arranged at different positions in a horizontal direction of a bumper fixed to a vehicle, respectively, each of the ultrasonic sensors having an input and output surface and being configured:
• to emit ultrasonic waves along a beam axis from the input and output surface in accordance with an output electric signal;
• and also to receive incoming ultrasonic waves through the input and output surface to convert the incoming ultrasonic waves into an input electric signal;
• and
• a controller configured:
• to supply the output electric signal to each of the ultrasonic sensors;
• and also to judge whether or not at least one obstacle is present in a maximum detection area based on at least input electric signals from the ultrasonic sensors, said maximum detection area being covered with the ultrasonic sensors, wherein
• the ultrasonic sensors comprise first and second ultrasonic sensors each of which is located at either side of the bumper so that its own beam axis has an angle deflected in a horizontal direction from a surface-normal direction of the bumper and is directed towards an intermediate portion of the bumper, and
• the controller is configured to judge whether or not at least one obstacle is present in the maximum detection area based on first and second self-signals and first and second mutual signals,
• the first self-signal corresponding to an input electric signal obtained when the first ultrasonic sensor receives ultrasonic waves emitted from the first ultrasonic sensor,
• the second self-signal corresponding to an input electric signal obtained when the second ultrasonic sensor receives ultrasonic waves emitted from the second ultrasonic sensor,
• the first mutual signal corresponding to an input electric signal obtained when the second ultrasonic sensor receives ultrasonic waves emitted from the first ultrasonic sensor, and
• the second mutual signal corresponding to an input electric signal obtained when the first ultrasonic sensor receives ultrasonic waves emitted from the second ultrasonic sensor.