Huan Chang

US Patent:

20130252633, Sep 26, 2013

Filed:

May 17, 2013

Appl. No.:

13/896726

Inventors:

Sam Song Liang - Palo Alto CA, US
Huan Chang - Menlo Park CA, US
Jun Yang - Milpitas CA, US
Zhigang Liu - Sunnyvale CA, US
Yun Fu - Cupertino CA, US
Chenyu Wang - Mountain View CA, US
Ying Chang - Stanford CA, US

Assignee:

ALOHAR MOBILE INC. - Palo Alto CA

International Classification:

H04W 4/02

US Classification:

4554561

Abstract:

Methods, systems and apparatuses for automatically determining user stays of a user of a mobile device are disclosed. One embodiment includes a network server operative to receive sensed location information of a mobile device. Further, the network server and/or a controller of the mobile device are operative to determine the mobile device is within a specific distance of a specific location for at least specific minimum time duration based on the location information, determine a start time of a user stay based on the location information, the specific location and the specific distance, and determine an end time of the user stay based on the location information, the specific location and the specific distance.

US Patent:

20220317313, Oct 6, 2022

Filed:

Jun 21, 2022

Appl. No.:

17/845773

Inventors:

- Cupertino CA, US
Huan Yang CHANG - San Jose CA, US

Assignee:

PlusAI, Inc. - Cupertino CA

International Classification:

G01S 19/23
G01S 19/14

Abstract:

The present teaching relates to apparatus, method, medium, and implementations for initiating sensor calibration. A first GPS signal is received by a GPS receiver residing in an ego vehicle and is used to determine a first geo-position of the ego vehicle. A GPS related signal transmitted by a fiducial marker is received and is used to obtain a second geo-position of the fiducial marker. A distance between the ego vehicle and the fiducial marker is determined based on the first and second geo-positions and is used to determine whether to initiate calibration of one or more sensors using the fiducial marker.

US Patent:

20210316743, Oct 14, 2021

Filed:

Apr 14, 2020

Appl. No.:

16/847847

Inventors:

- Central, HK
Huan Yang CHANG - Santa Clara CA, US

International Classification:

B60W 50/06
G01S 19/51
G06T 7/80

Abstract:

The present teaching relates to different configurations for facilitating calibration of multiple sensors of different types. A plurality of fiducial markers are arranged in space for simultaneously calibrating multiple sensors of different types. Each of the plurality of fiducial markers has a feature point thereon and is provided to enable the multiple sensors to calibrate by detecting the features points and estimating their corresponding 3D coordinates with respect to respective coordinate systems of the multiple sensors.

US Patent:

20210318149, Oct 14, 2021

Filed:

Apr 14, 2020

Appl. No.:

16/847972

Inventors:

- Central, HK
Huan Yang CHANG - Santa Clara CA, US

International Classification:

G01D 18/00
B60W 50/06
G06T 7/73
G06T 7/80

Abstract:

The present teaching relates to apparatus, method, medium, and implementations for simultaneously calibrating multiple sensors of different types. Multiple sensors of different types are first activated to initiate simultaneous calibration thereof based on a 3D construct including a plurality of fiducial marks. Sensors of different types including visual and depth based sensors operate in their respective coordinate systems. Each of the sensors is calibrated by acquiring sensor information of the 3D construct, detecting a feature point on each of the plurality of fiducial markers based on the sensor information, estimating a set of 3D coordinates, with respect to its coordinate system, corresponding to the detected feature points, based on which calibration parameters are generated. Sets of 3D coordinates derived in different coordinate systems are then used to compute at least one transformation matrix for corresponding at least one pair of the plurality of sensors.

US Patent:

20210318448, Oct 14, 2021

Filed:

Apr 14, 2020

Appl. No.:

16/848073

Inventors:

- Central, HK
Huan Yang CHANG - Santa Clara CA, US

International Classification:

G01S 19/23
G01S 19/14

Abstract:

The present teaching relates to apparatus, method, medium, and implementations for initiating sensor calibration. A first GPS signal is received by a GPS receiver residing in an ego vehicle and is used to determine a first geo-position of the ego vehicle. A GPS related signal transmitted by a fiducial marker is received and is used to obtain a second geo-position of the fiducial marker. A distance between the ego vehicle and the fiducial marker is determined based on the first and second geo-positions and is used to determine whether to initiate calibration of one or more sensors using the fiducial marker.