Method for controlling an ultrasonic sensor and ultrasonic sensor

• US 8,760,971 B2
• Filed: 04/12/2011
• Issued: 06/24/2014
• Est. Priority Date: 04/15/2010
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Karl, Matthias
• Primary Examiner(s): Alsomiri, Isam
• Assistant Examiner(s): HULKA, JAMES R
• Application Number:
  US13/641,260
• Publication Number:
  US 20130100776A1
• Time in Patent Office: 1,169 Days
• Field of Search: 367/118
• US Class Current: 367/137
• CPC Class Codes: G01H 13/00 Measuring resonant frequency
• CPC Class Codes: G01N 29/34 Generating the ultrasonic, sonic or infrasonic waves , e.g. electronic circuits specially adapted therefor
• CPC Class Codes: G01S 1/751 Mounting or deployment thereof
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G01S 7/521 Constructional features
• CPC Class Codes: G10K 9/122 using piezoelectric driving means G10K9/121 takes precedence

Abstract

An ultrasonic sensor has: a diaphragm that includes at least two partial regions for emitting and/or receiving ultrasonic signals, the two partial regions possessing different resonance characteristics; and at least one electromechanical transducer coupled to the diaphragm, to which transducer a control signal having at least two different control signal frequencies is applied. In this context, a first control signal frequency is in the range of a resonant frequency of a first partial region of the diaphragm, and a second control signal frequency is in the range of a resonant frequency of a second partial region of the diaphragm. Alternatively, two electromechanical transducers are used, which are coupled to a diaphragm and have different resonance characteristics.

Claims

1. An ultrasonic sensor, comprising:

a diaphragm which has at least two partial regions for at least one of emitting and receiving ultrasonic signals, the two partial regions having different resonance characteristics;

a chassis attached to the diaphragm, the chassis having negligible vibrational amplitudes; and

at least one electromechanical transducer coupled to the diaphragm, wherein a control signal having at least two different control signal frequencies is applied to the electromechanical transducer, a first control signal frequency being in the range of a resonant frequency of a first partial region of the diaphragm, and a second control signal frequency being in the range of a resonant frequency of a second partial region of the diaphragm;

wherein the electromechanical transducer is attached to the diaphragm by an adhesive layer, and is attached to a control unit via electrical leads.

2. The ultrasonic sensor as recited in claim 1, wherein the different resonance characteristics are produced by different thicknesses of the at least two partial regions of the diaphragm.

3. The ultrasonic sensor as recited in claim 2, wherein the thickness of the diaphragm changes in a stepped manner between the at least two partial regions.

4. The ultrasonic sensor as recited in claim 2, wherein the thickness of the diaphragm changes continuously at least in a transition area between the first partial region and the second partial region.

5. The ultrasonic sensor as recited in claim 4, wherein the diaphragm is configured symmetrically.

6. The ultrasonic sensor as recited in claim 2, wherein the diaphragm is configured asymmetrically.

7. The ultrasonic sensor as recited in claim 1, wherein the chassis is decouplably attached to the diaphragm.

8. The ultrasonic sensor as recited in claim 1, wherein an edge region of the diaphragm directly adjacent to the chassis is thinner than the two partial regions of the diaphragm.

9. A method for controlling an ultrasonic sensor having a diaphragm which includes at least two partial regions possessing different resonance characteristics, and at least one electromechanical transducer being coupled to the diaphragm, the method comprising:

applying a control signal having at least two different control signal frequencies to the electromechanical transducer, a first control signal frequency being in the range of a resonant frequency of a first partial region of the diaphragm, and a second control signal frequency being in the range of a resonant frequency of a second partial region of the diaphragm;

wherein a chassis is attached to the diaphragm, the chassis having negligible vibrational amplitudes; and

wherein the electromechanical transducer is attached to the diaphragm by an adhesive layer, and is attached to a control unit via electrical leads.