US 12,372,643 B2Granted

Coded ultrasonic sensing with staggered bursts

AssigneeTexas Instruments Incorporated

InventorsLei Ding, Srinath Mathur Ramaswamy, Anand Gopalan, Vaibhav Garg, Anand Ganesh Dabak

Life of this patent

Estimating the term…

Loading patent…

Abstract

Ultrasonic ranging systems and methods that use coding to distinguish emitted bursts from multiple transducers temporally stagger the bursts emitted from the transducers. The stagger delay between bursts from different transducers in a sensing frame can be randomized between different sensing frames to prevent blind zones. The stagger delay can be relatively small (e.g., between 3 ms and 10 ms) as compared to delays required between bursts in a single-tone ranging system (which would need to be more on the order of between 30 ms and 40 ms, depending on the maximum detecting range of the ranging system). The coding of bursts can be selected to utilize the entire bandwidth of the bursting transducer so as to preserve short-range sensitivity over transducer ringing. Schemes in which some transducers in a system only listen for bursts from other transducers but do not themselves burst within a sensing frame are also described.

Claims26

Dependent claims

A method of ultrasonic ranging comprising:

from a first ultrasonic transducer, emitting a first ultrasonic acoustic burst signal representing a first code during a first period;
from a second ultrasonic transducer, emitting a second ultrasonic acoustic burst signal representing a second code during a second period after the first period, the first period and the second period being separated by a delay time;
preventing the first ultrasonic transducer from transmitting any ultrasonic acoustic burst signal during the second period;
preventing the second ultrasonic transducer from transmitting any ultrasonic acoustic burst signal during the first period;
at the first ultrasonic transducer, receiving an acoustic signal, and converting the acoustic signal to a sensor signal;
generating a correlation result responsive to a correlation between the sensor signal and the first code or the second code;
determining, based on the correlation result, that the acoustic signal is a reflection of the second ultrasonic acoustic burst signal;
and
computing a time-of-flight for the second ultrasonic acoustic burst signal based on:
a time difference between when the first period starts and when the first ultrasonic transducer starts receiving the acoustic signal;
the correlation result indicating that the acoustic signal is a reflection of the second ultrasonic acoustic burst signal;
and the delay time.

9 more elements

An ultrasonic detection system comprising:

a first ultrasonic transducer having a first transducer input and a first sensor output and configured to:
responsive to a first control signal at the first transducer input, emit a first ultrasonic acoustic burst signal representing a first code;
responsive to a second control signal at the first transducer input, stop emitting any ultrasonic acoustic burst signal;
and
receive a first acoustic signal, convert the first acoustic signal to a first sensor signal, and provide the first sensor signal at the first sensor output;
a second ultrasonic transducer having a second transducer input and a second sensor output and configured to:
responsive to a third control signal at the second transducer input, emit a second ultrasonic acoustic burst signal representing a second code;
and
responsive to a fourth control signal at the second transducer input, stop emitting any ultrasonic acoustic burst signal;
receive a second acoustic signal, convert the second acoustic signal to a second sensor signal, and provide the second sensor signal at the second sensor output;
a correlator having a correlator input and a correlator output, the correlator input coupled to the first and second sensor outputs, and the correlator configured to:
generate a correlation result responsive to a correlation between the first sensor signals and the first code or the second code;
and
provide the correlation result at the correlator output;
and
a control circuit having a control input coupled to the correlator output, a first control output coupled to the first transducer input, and a second control output coupled to the second transducer input, and the control circuit configured to:
during a first period, provide the first control signal at the first control output, and provide the fourth control signal at the second control output;
during a second period after the first period, provide the second control signal at the first control output, and provide the third control signal at the second control output, in which the first and second periods are separated by a delay time;
receive the correlation result at the control input;
and
compute a time-of-flight based on the correlation result and the delay time.

18 more elements

An ultrasonic ranging system comprising:

a first sensor module including:
a first ultrasonic transducer having a first transducer input and a first sensor output and configured to:
responsive to a first control signal at the first transducer input, emit a first ultrasonic burst signal representing a first code;
responsive to a second control signal at the first transducer input, stop emitting any ultrasonic acoustic burst signal;
and
receive a first acoustic signal, convert the first acoustic signal to a first sensor signal, and provide the first sensor signal at the first sensor output;
a first correlator having a first correlator input and a first correlator output, the first correlator input coupled to the first sensor output, the first correlator configured to:
generate a first correlation result responsive to a correlation between the first sensor signal with the first code or a second code;
and
provide the first correlation result at the first correlator output;
and
a first processing circuit having a first processing input and a first processing output, the first processing input coupled to the first correlator output, and the first processing circuit configured to:
compute a first time-of-flight of the first acoustic burst signal based on the first correlation result;
and
provide the first time-of-flight at the first processing output;
a second sensor module including:
a second ultrasonic transducer having a second transducer input and a second sensor output and configured to:
responsive to a third control signal at the second transducer input, emit a second ultrasonic burst signal representing the second code;
responsive to a fourth control signal at the second transducer input, stop emitting any ultrasonic acoustic burst signal;
and
receive a second acoustic signal, convert the second acoustic signal to a second sensor signal, and provide the second sensor signal at the second sensor output;
a second correlator having a second correlator input and a second correlator output, the second correlator input coupled to the second sensor output, and the second correlator configured to:
generate a second correlation result responsive to a correlation between the second sensor signal with the first code or the second code;
and
provide the second correlation result at the second correlator output;
and
a second processing circuit having a second processing input and a second processing output, the second processing input coupled to the second correlator output, and the second processing circuit configured to:
compute a second time-of-flight of the second acoustic burst signal based on the second correlation result;
and
provide the second time-of-flight at the second processing output;
and
a controller having a first control input, a second control input, a first control output, and a second control output, the first control input coupled to the first processing output, the second control input coupled to the second processing output, the first control output coupled to the first transducer input, and the second control output coupled to the second transducer input, and the controller configured to:
during a first period, provide the first control signal at the first control input, and provide the fourth control signal at the second control input;
during a second period after the first period, provide the second control signal at the first control input, and provide the third control signal at the second control input, in which the first and second periods are separated by a delay time;
receive, at the first control input, the first time-of-flight;
receive, at the second control input, the second time-of-flight;
and
adjust one of the first or second time-of-flights based on the delay time.

35 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/426,779Filed 30 May 2019 · us provisional application
Priority: 11 Jan 2019
Published: US 2020/0225345 A116 Jul 2020
Granted: 29 Jul 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G01S 15/102
Using transmission of interrupted, pulse-modulated waves: using transmission of pulses having some particular characteristics
G01S 7/526
Details of pulse systems: receivers
G01S 15/878
Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector: wherein…
G01S 15/931
For anti-collision purposes: of land vehicles