Ultrasonic measurement apparatus and method for evaluating an ultrasonic signal

• US 9,297,891 B2
• Filed: 07/14/2010
• Issued: 03/29/2016
• Est. Priority Date: 07/20/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Karl, Matthias
• Primary Examiner(s): Ratcliffe, Luke
• Assistant Examiner(s): Ndure Jobe, Amienatta M
• Application Number:
  US13/383,164
• Publication Number:
  US 20120176864A1
• Time in Patent Office: 2,085 Days
• Field of Search: 367/89, 701/301
• US Class Current: 1/1
• CPC Class Codes: G01S 15/52 Discriminating between fixed and moving objects or between objects moving at different speeds
• CPC Class Codes: G01S 15/582 using transmission of interrupted pulse-modulated waves and based upon the Doppler effect resulting from movement of targets
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G01S 7/5276 using analogue techniques
• CPC Class Codes: G01S 7/539 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Abstract

An ultrasonic measurement apparatus is described having a receiving device which determines a measurement sequence relating to a time variation of the period lengths of an ultrasonic signal received from an in-vehicle and/or external ultrasonic transmitter, a comparison device which determines a comparison information item relating to a deviation of the determined measurement sequence from at least one reference sequence, and an evaluation device which determines, taking into consideration the determined comparison information item, an information item relating to a signal form transmitted by the ultrasonic transmitter, a relative speed between the receiving device and the ultrasonic transmitter, a relative speed of at least one reflecting object situated in a transmission path between the receiving device and the ultrasonic transmitter, and/or a shape feature of the at least one reflecting object. A method for evaluating an ultrasonic signal is also described.

Claims

1. An ultrasonic measurement apparatus for a vehicle, comprising:

a receiving device configured to receive an ultrasonic signal emitted by at least one of an in-vehicle and external ultrasonic transmitter and to determine and provide a measurement sequence relating to a time variation of period lengths of the received ultrasonic signal;

a comparison device on which at least one reference sequence is stored and which is configured to compare the determined measurement sequence with the at least one reference sequence and to determine a comparison information item relating to a deviation of the determined measurement sequence from the at least one reference sequence; and

an evaluation device configured to determine, based on the determined comparison information item, at least one of an information item relating to a signal form transmitted by the ultrasonic transmitter, a relative speed between the receiving device and the external ultrasonic transmitter, a relative speed of at least one reflecting object situated in a transmission path between the receiving device and the ultrasonic transmitter, and a shape feature of the at least one reflecting object;

wherein the measurement sequence determined by the receiving device includes at least one of a sequence of positive period lengths of the ultrasonic signal, a sequence of negative period lengths of the ultrasonic signal, a sequence of positive period length deviations of the ultrasonic signal from a reference period length, a sequence of negative period length deviations of the ultrasonic signal from a reference period length, a sequence of frequencies of the ultrasonic signal, and a sequence of frequency deviations of the ultrasonic signal from a reference frequency.

2. The ultrasonic measurement apparatus as recited in claim 1, wherein the receiving device includes a threshold switch with a predefined significance threshold, which is configured to filter the ultrasonic signal in such a manner that the measurement sequence is determined based on signal regions of the ultrasonic signal having an intensity above the significance threshold and filtering out signal regions of the ultrasonic signal having an intensity below the significance threshold.

3. The ultrasonic measurement apparatus as recited in claim 1, wherein the receiving device includes a binary signal output device which is configured to convert at least regions of the received ultrasonic signal into a binary signal, and wherein the receiving device includes at least one time-measuring unit which is configured to determine, based on the binary signal provided, at least one of the sequence of positive period length deviations and the sequence of negative period length deviations from the reference period length as a measurement sequence.

4. The ultrasonic measurement apparatus as recited in claim 1, wherein the receiving device includes a first time-measuring unit and a second time-measuring unit, and wherein the first time-measuring unit is configured to ascertain the positive period length deviation from the reference period length and the second time-measuring unit is configured to ascertain the negative period length deviation from the reference period length.

5. The ultrasonic measurement apparatus as recited in claim 1, wherein at least a first reference sequence relating to a first comparison shape feature of the at least one reflecting object and a second reference sequence relating to a second comparison shape feature of the at least one reflecting object are stored on the comparison device.

6. The ultrasonic measurement apparatus as recited in claim 1, wherein the evaluation device is configured to determine, based on the time variation of the period length at the beginning and end of an echo, at least a first relative speed and a second relative speed, deviating from the first relative speed, of the at least one object, and wherein the evaluation device is additionally configured to recognize, in a determination of the first relative speed and the deviating second relative speed, that during a time interval corresponding to the partial sequence an ultrasonic signal reflected toward at least two different objects is received by the receiving device.

7. A method for evaluating an ultrasonic signal emitted by an in-vehicle and/or external ultrasonic transmitter, comprising:

determining a measurement sequence relating to a time variation of period lengths of a received ultrasonic signal;

comparing the determined measurement sequence with at least one reference sequence, wherein a comparison information item relating to a deviation of the measurement sequence from the at least one reference sequence is determined; and

determining at least one of an information item relating to a signal form transmitted by the ultrasonic transmitter, a relative speed between the receiving device and the external ultrasonic transmitter, a relative speed of at least one reflecting object situated in a transmission path between the receiving device and the ultrasonic transmitter, and a shape feature of the at least one reflecting object, taking the determined comparison information item into consideration;

wherein the measurement sequence determined by the receiving device includes at least one of a sequence of positive period lengths of the ultrasonic signal, a sequence of negative period lengths of the ultrasonic signal, a sequence of positive period length deviations of the ultrasonic signal from a reference period length, a sequence of negative period length deviations of the ultrasonic signal from a reference period length, a sequence of frequencies of the ultrasonic signal, and a sequence of frequency deviations of the ultrasonic signal from a reference frequency.

8. The method as recited in claim 7, wherein at least one of the following is determined as the measurement sequence:

a sequence of positive period lengths of the ultrasonic signal, a sequence of negative period lengths of the ultrasonic signal, a sequence of positive period length deviations of the ultrasonic signal from a reference period length, a sequence of negative period length deviations of the ultrasonic signal from a reference period length, a sequence of frequencies of the ultrasonic signal, and a sequence of frequency deviations of the ultrasonic signal from a reference frequency.

9. The method as recited in claim 7, wherein if, based only on the time variation of the period length at the beginning and end of an echo, at least a first relative speed and a second relative speed, deviating from the first relative speed, of the at least one object is determined, it is determined that during a time interval corresponding to the partial sequence an ultrasonic signal reflected toward at least two different external objects is received.