Method for controlling an ultrasonic sensor and ultrasonic sensor

• US 10,067,099 B2
• Filed: 05/06/2014
• Issued: 09/04/2018
• 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): Hulka, James R
• Application Number:
  US14/270,641
• Publication Number:
  US 20140238135A1
• Time in Patent Office: 1,582 Days
• Field of Search: 367 92
• 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 a first partial region and a second partial region for at least one of emitting and receiving ultrasonic signals;

at least a first electromechanical transducer coupled to the first partial region and a second electromechanical transducer coupled to the second partial region, wherein the first electromechanical transducer and the second electromechanical transducer have different resonance characteristics; and

a control unit configured to apply at least i) a first control signal to control the first electromechanical transducer, the first control signal having a first control signal frequency that is a resonant frequency of the first partial region of the diaphragm; and

ii) a second control signal to control the second electromechanical transducer, the second control signal having a second control signal frequency that is a resonant frequency of the second partial region of the diaphragm;

wherein the first control signal the second control signal are different from each other and independent of each other,

wherein the resonant frequency of the first partial region results from resonance characteristics of the diaphragm at the first partial region and resonance characteristics of the first electromechanical transducer;

wherein the resonant frequency of the second partial region results from resonance characteristics of the diaphragm at the second partial region and resonance characteristics of the second electromechanical transducer;

wherein the resonant frequency of the first partial region is different from the resonant frequency of the second partial region so that the ultrasonic sensor is operable at two different resonance frequencies.

2. The ultrasonic sensor as recited in claim 1, wherein the two transducers have different geometric dimensions.

3. The ultrasonic sensor as recited in claim 1, wherein the two transducers are symmetrically coupled to the diaphragm.

4. The ultrasonic sensor as recited in claim 1, wherein the transducers are asymmetrically coupled to the diaphragm.

5. The ultrasonic sensor as recited in claim 1, further comprising:

a chassis attached to the diaphragm, the chassis having negligible vibrational amplitudes.

6. The ultrasonic sensor as recited in claim 5, wherein the chassis is decouplably attached to the diaphragm.

7. 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.

8. The ultrasonic sensor as recited in claim 1, wherein the first electromechanical transducer is attached to the first partial region of the diaphragm by a first adhesive layer;

wherein the first electromechanical transducer is attached to a first control unit via electrical leads;

wherein the second electromechanical transducer is attached to the first partial region of the diaphragm by a second adhesive layer; and

wherein the second electromechanical transducer is attached to a second control unit via electrical leads.

9. The ultrasonic sensor as recited in claim 1, wherein the first electromechanical transducer has a first geometric dimension and a first resonance characteristic;

wherein the second electromechanical transducer has a second geometric dimension and a second resonance characteristic;

wherein the first geometric dimension is different than the second geometric dimension; and

wherein the second resonance characteristic is different than the second resonance characteristic.

10. A method for controlling an ultrasonic sensor having a diaphragm which includes at least a first partial region and a second partial region for at least one of emitting and receiving ultrasonic signals, at least a first electromechanical transducer coupled to the first partial region and a second electromechanical transducer coupled to the second partial region, wherein the first electromechanical transducer and the second electromechanical transducer have different resonance characteristics, the method comprising:

applying at least i) a first control signal to control the first electromechanical transducer, the first control signal having a first control signal frequency that is a resonant frequency of the first partial region of the diaphragm; and

ii) a second control signal to control the second electromechanical transducer, the second control signal having a second control signal frequency that is a resonant frequency of the second partial region of the diaphragm;

wherein the first control signal the second control signal are different from each other and independent of each other,

wherein the resonant frequency of the first partial region results from resonance characteristics of the diaphragm at the first partial region and resonance characteristics of the first electromechanical transducer;

wherein the resonant frequency of the second partial region results from resonance characteristics of the diaphragm at the second partial region and resonance characteristics of the second electromechanical transducer;

wherein the resonant frequency of the first partial region is different from the resonant frequency of the second partial region so that the ultrasonic sensor is operable at two different resonance frequencies.

11. The method as recited in claim 10, wherein a chassis is attached to the diaphragm, the chassis having negligible vibrational amplitudes.

12. The method as recited in claim 11, wherein the chassis is decouplably attached to the diaphragm.

13. The method as recited in claim 10, wherein an edge region of the diaphragm directly adjacent to the chassis is thinner than the two partial regions of the diaphragm.

14. The method as recited in claim 10, wherein the first electromechanical transducer is attached to the first partial region of the diaphragm by a first adhesive layer;

wherein the first electromechanical transducer is attached to a first control unit via electrical leads;

wherein the second electromechanical transducer is attached to the first partial region of the diaphragm by a second adhesive layer; and

wherein the second electromechanical transducer is attached to a second control unit via electrical leads.

15. The method as recited in claim 10, wherein the first electromechanical transducer has a first geometric dimension and a first resonance characteristic, and the second electromechanical transducer has a second geometric dimension and a second resonance characteristic;

wherein the first geometric dimension is different than the second geometric dimension; and

wherein the second resonance characteristic is different than the second resonance characteristic.