Abstract: An object detection device includes a wave transmitter to transmit a sound wave to an object, a wave receiver to receive the sound wave and generate a signal representing a reception result, and a controller to control transmission of the sound wave by the wave transmitter and obtain the receive signal from the wave receiver. The controller is configured or programmed to output a transmit signal to cause the wave transmitter to transmit the sound wave and obtain a corresponding receive signal. The controller is configured or programmed to generate detection information about the object by performing complexification on a correlation signal representing a correlation between the transmit signal and the receive signal. A signal corrector is configured or programmed to correct any of the correlation signal, the receive signal, and the transmit signal to mitigate a direct-current component in the correlation signal targeted for the complex analysis.

Abstract: A displacement detection device includes a transmitter, a receiver, and a controller configured or programmed to output a first transmission signal to the transmitter to transmit a modulated wave and acquire a responsive first reception signal in a first measurement period, extract first phase information indicating a phase defined in a correlation between a first transmission signal and a reception signal, output a second transmission signal to the transmitter and acquire a responsive second reception signal in a second measurement period after the first measurement period, extract second phase information indicating a phase defined in a correlation between the second transmission signal and reception signal, and detect a displacement of an object between the first and second measurement periods, depending on a difference between the first and second phase information.