US 12,265,186 B2
Ultrasonic cliff detection and depth estimation using tilted sensors
Daniela Hall, Eybens (FR); Tony Lei, San Francisco, CA (US); Zhongyang Li, Noyarey (FR); and Joe Youssef, Noyarey (FR)
Assigned to InvenSense, Inc., San Jose, CA (US)
Filed by InvenSense, Inc., San Jose, CA (US)
Filed on Nov. 15, 2022, as Appl. No. 17/987,304.
Application 17/987,304 is a continuation in part of application No. 17/987,151, filed on Nov. 15, 2022.
Claims priority of provisional application 63/279,940, filed on Nov. 16, 2021.
Claims priority of provisional application 63/279,996, filed on Nov. 16, 2021.
Prior Publication US 2023/0152434 A1, May 18, 2023
Int. Cl. G01S 7/521 (2006.01); B06B 1/02 (2006.01); G01S 15/931 (2020.01)
CPC G01S 7/521 (2013.01) [B06B 1/0261 (2013.01); G01S 15/931 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A robotic cleaning appliance comprising:
a housing to which is coupled a surface treatment item;
a sensor assembly coupled with the housing, the sensor assembly comprising:
a first sonic transducer configured to transmit sonic signals toward a surface beneath the robotic cleaning appliance wherein the sonic signals reflect from the surface as corresponding returned signals;
a second sonic transducer configured to receive the corresponding returned signals reflected from the surface; and
an acoustic interface coupled with the first sonic transducer and the second sonic transducer and having an external surface, the acoustic interface comprising:
a first acoustic opening port defined in the external surface, coupled with the first sonic transducer, and configured to emit the sonic signals directed from the first sonic transducer toward the surface;
a first annular ring defined in the external surface, at a different height than the external surface, around the first acoustic opening port;
a first horn coupled between the first sonic transducer and the first acoustic opening port, and tilted from orthogonal with the external surface;
a second acoustic opening port defined in the external surface, coupled with the second sonic transducer, and configured to direct the corresponding returned signals to the second sonic transducer;
a second annular ring defined in the external surface, at a different height than the external surface, around the second acoustic opening port; and
a second horn coupled between the second sonic transducer and the second acoustic opening port, and tilted from orthogonal with the external surface by a same angle of tilt as the first horn, wherein the first horn and the second horn are substantially parallel and are pointed in a direction designated as a front of the robotic cleaning appliance;
wherein the first annular ring and the second annular ring operate to attenuate direct path echoes from a subset of the transmitted sonic signals which attempt to travel across the external surface between the first acoustic opening port and the second acoustic opening port.