ULTRASOUND SENSOR

• US 20150003205A1
• Filed: 01/22/2013
• Published: 01/01/2015
• Est. Priority Date: 01/31/2012
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Urase, Hiroshi
• Granted Patent: US 9,581,693 B2
• Time in Patent Office: Days
• US Class Current: 367/93
• CPC Class Codes: G01S 15/04 Systems determining presence of a target
• CPC Class Codes: G01S 7/527 Extracting wanted echo signals Doppler systems G01S15/50

Abstract

An ultrasound sensor includes a transmitting/receiving device configured to transmit/receive ultrasound waves; and a controller configured to make the transmitting/receiving device transmit an ultrasound burst wave, as each of the ultrasound waves, and detect an object through a reception signal that is output from the transmitting/receiving device. The controller is configured to shift operation mode to a detecting mode, when the object is detected in a monitoring mode. In the monitoring mode, the number of waves included in the ultrasound burst wave is changed in two stages. The detecting mode is of detecting the object, using the ultrasound burst wave having the waves that are being used at a time point when the object is detected in the monitoring mode.

Claims

1. An ultrasound sensor, comprising:

a transmitting/receiving device configured to transmit/receive ultrasound waves; and

a controller configured to provide a transmission signal to the transmitting/receiving device to make the transmitting/receiving device transmit an ultrasound burst wave, as each of the ultrasound waves,

the controller being configured to detect an object in a detection area to which the ultrasound waves are transmitted, through a reception signal that is output from the transmitting/receiving device,

wherein the transmitting/receiving device is configured to more increase amplitude of the reception signal, as a number of waves included in the received ultrasound burst wave is larger in a range where the amplitude of the reception signal is not saturated, and

wherein the controller is configured to define, as a pulse number, the number of waves included in the ultrasound burst wave,

the controller being configured to determine that the object is present, when a reception signal level is equal to or more than a threshold, the reception signal level being equivalent to the amplitude of the reception signal that corresponds to waves reflected by the object,

the controller being configured to cyclically select the pulse number to be used from a plurality of pulse numbers that are set in stages, and detect the object with the pulse number being used when having determined that the object is present.

2. The ultrasound sensor according to claim 1,

wherein the controller is configured to store at least a first pulse number and a second pulse number that is more than the first pulse number,

the controller being configured to operate in:

a monitoring mode of transmitting/receiving the ultrasound burst wave while cyclically selecting the pulse number to be used from the first and second pulse numbers until preliminarily detecting presence of the object;

or

a detecting mode of transmitting/receiving the ultrasound burst wave with the pulse number, selected from the first and second pulse numbers, being used at a time point when having preliminarily detected the presence of the object.

3. The ultrasound sensor according to claim 2,

wherein the monitoring mode in the controller includes:

a first time period of transmitting/receiving the ultrasound burst wave repeatedly one or more times with the first pulse number in advance; and

a second time period of transmitting/receiving the ultrasound burst wave repeatedly one or more times with the second pulse number after end of the first time period, and

wherein when a sum of the first and second time periods is defined as a cycle, the controller is configured to repeat the cycle until preliminarily detecting the presence of the object.

4. The ultrasound sensor according to claim 1,

wherein the controller is configured to determine that the object is present, when the reception signal level is equal to or more than the threshold in a prescribed reception period,

the controller being configured to change the prescribed reception period according to the pulse number being used.

5. The ultrasound sensor according to claim 1,

wherein the controller is configured to more reduce the threshold as a distance to the object is longer, when having determined that the object is present.

6. The ultrasound sensor according to claim 2,

wherein the controller is configured to more reduce the threshold as a distance to the object is longer, when having determined that the object is present.

7. The ultrasound sensor according to claim 3,

wherein the controller is configured to more reduce the threshold as a distance to the object is longer, when having determined that the object is present.

8. The ultrasound sensor according to claim 4,

wherein the controller is configured to more reduce the threshold as a distance to the object is longer, when having determined that the object is present.