Object detection device

Patent metadata

Field	Value
Publication number	US-2024255637-A1
Application number	US-202418614786-A
Country	US
Kind code	A1
Filing date	Mar 25, 2024
Priority date	Jul 29, 2022
Publication date	Aug 1, 2024
Grant date	—

Abstract

An object detection device includes a transmitter to generate an acoustic wave as a signal wave based on a predetermined transmission signal and transmit the signal wave toward an object, a receiver provided separately from the transmitter and to receive the acoustic wave to generate a reception signal, and a controller to generate the transmission signal to control the signal wave from the transmitter. The receiver has frequency characteristics such that the reception signal fluctuates when the receiver resonates. The transmission signal is set according to the frequency characteristics of the receiver to reduce or prevent a resonance of the receiver at a time of reception of the signal wave from the transmitter.

First claim

What is claimed is:

1 . An object detection device to detect an object by transmitting and receiving an acoustic wave, the object detection device comprising:
a transmitter to generate the acoustic wave as a signal wave based on a predetermined transmission signal and transmit the signal wave toward the object; a receiver provided separately from the transmitter and to receive the acoustic wave to generate a reception signal; and a controller configured or programmed to generate the transmission signal to control the signal wave transmitted from the transmitter; wherein the receiver has frequency characteristics such that the reception signal fluctuates when the receiver resonates; and the transmission signal is set according to the frequency characteristics of the receiver to reduce or prevent resonance of the receiver at a time of reception of the signal wave from the transmitter.

2 . The object detection device according to claim 1 , wherein
the transmission signal has a frequency spectrum including a node in which an intensity of a frequency component is less than intensities of surrounding frequency components; and the transmission signal is set such that a resonant frequency in the frequency characteristics of the receiver is included in the node.

3 . The object detection device according to claim 2 , wherein the transmission signal is set such that the resonant frequency is included in the node at a lowest frequency among multiple nodes provided at regular intervals in the frequency spectrum.

4 . The object detection device according to claim 1 , wherein the transmission signal is set to have a signal length indicating a time length of the signal wave so that the resonance of the receiver at the time of reception of the signal wave is reduced or prevented.

5 . The object detection device according to claim 4 , wherein the transmission signal has an impulse waveform with a pulse width set as the signal length.

6 . The object detection device according to claim 1 , wherein, based on the transmission signal and the reception signal, the controller is configured or programmed to detect, as a distance to the object, a distance corresponding to a period from when the signal wave is transmitted from the transmitter until when the signal wave reflected by the object is received by the receiver.

7 . The object detection device according to claim 1 , wherein
the controller is configured or programmed to:
determine whether the object is at a short distance less than a predetermined distance;
generate, as a first transmission signal, the transmission signal that is set to reduce or prevent the resonance of the receiver resulting from the reception of the signal wave when it is determined that the object is at the short distance; and
generate a second transmission signal different from the first transmission signal when it is determined that the object is not at the short distance.

8 . The object detection device according to claim 7 , wherein the controller is configured or programmed to cause the transmitter to transmit the signal wave according to the second transmission signal and perform correlation processing based on the reception signal, which indicates a reception result of the receiver after the transmission of the signal wave, to detect a distance to the object.

9 . The object detection device according to claim 1 , wherein the transmitter includes a thermophone to generate the signal wave by generating heat and stopping the generation of heat.

10 . The object detection device according to claim 1 , wherein the receiver includes a micro electro-mechanical systems microphone.

11 . The object detection device according to claim 1 , further comprising a reception circuit including a sensor amplifier to amplify the reception signal from the receiver and output the reception signal.

12 . The object detection device according to claim 1 , wherein the controller includes a microcomputer.

13 . The object detection device according to claim 1 , further comprising a storage to store at least one of data or programs read by the controller.

14 . The object detection device according to claim 13 , wherein the storage is a flash memory.

Assignees

• Murata Manufacturing Co

Inventors

• Sasaki Shinichi
• Asada Takaaki
• Watabe Yuuma

Classifications

• G01S7/52006

  with provision for compensating the effects of temperature · CPC title

• G01S7/527

  Extracting wanted echo signals {(Doppler systems G01S15/50)} · CPC title

• G01S15/931

  of land vehicles · CPC title

• G01S7/5276

  using analogue techniques · CPC title

• G01S15/102 Primary

  using transmission of pulses having some particular characteristics · CPC title