Steven Alexander

US Patent:

20110082585, Apr 7, 2011

Filed:

Aug 31, 2010

Appl. No.:

12/873018

Inventors:

Boris SOFMAN - Pittsburgh PA, US
Vladimir ERMAKOV - Santa Clara CA, US
Mark EMMERICH - San Jose CA, US
Steven ALEXANDER - Fremont CA, US
Nathaniel David MONSON - Mountain View CA, US

Assignee:

NEATO ROBOTICS, INC. - Mountain View CA

International Classification:

G06F 19/00
G06F 15/00
G06G 7/48

US Classification:

700259, 700258, 702150, 700245, 703 6

Abstract:

Techniques that optimize performance of simultaneous localization and mapping (SLAM) processes for mobile devices, typically a mobile robot. In one embodiment, erroneous particles are introduced to the particle filtering process of localization. Monitoring the weights of the erroneous particles relative to the particles maintained for SLAM provides a verification that the robot is localized and detection that it is no longer localized. In another embodiment, cell-based grid mapping of a mobile robot's environment also monitors cells for changes in their probability of occupancy. Cells with a changing occupancy probability are marked as dynamic and updating of such cells to the map is suspended or modified until their individual occupancy probabilities have stabilized. In another embodiment, mapping is suspended when it is determined that the device is acquiring data regarding its physical environment in such a way that use of the data for mapping will incorporate distortions into the map, as for example when the robotic device is tilted.

US Patent:

49470574, Aug 7, 1990

Filed:

May 1, 1989

Appl. No.:

7/345815

Inventors:

Walter S. Czarnocki - Schaumburg IL
Peter W. Harper - Crystal Lake IL
Kevin S. Moran - Algonquin IL
Steven W. Alexander - Schaumburg IL

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H01L 2716

US Classification:

307310

Abstract:

A mass fluid flow sensor is disclosed which utilizes a sensing bridge circuit to develop a sense (control) signal related to fluid flow. A fluid temperature variable resistor, separate from said bridge circuit, is utilized to implement temperature compensation so that a desired output signal is a function of sensed fluid flow, but is less dependent on fluid temperature than the sense (control) signal provided by the bridge circuit. A resistor in the bridge circuit is selected such that the sense (control) signal provided by the bridge circuit has a rate of change as a function of flow rate substantially independent of fluid temperature, but this sense signal still varies as a function of fluid temperature. This permits fluid temperature compensation of the bridge sense signal in a noncomplex and cost effective manner. An improved adjustable circuit (36-41) is provided for producing a desired temperature variable output signal (V. sub. os).

US Patent:

48541672, Aug 8, 1989

Filed:

Sep 9, 1987

Appl. No.:

7/094953

Inventors:

Walter S. Czarnocki - Schaumburg IL
Peter W. Harper - Crystal Lake IL
Kevin S. Moran - Algonquin IL
Steven W. Alexander - Schaumburg IL

Assignee:

Motorola Inc. - Schaumburg IL

International Classification:

G01F 168

US Classification:

7320419

Abstract:

A mass fluid flow sensor is disclosed which utilizes a sensing bridge circuit to develop a sense (control) signal related to fluid flow. A fluid temperature variable resistor, separate from said bridge circuit, is utilized to implement temperature compensation so that a desired output signal is a function of sensed fluid flow, but is less dependent on fluid temperature than the sense (control) signal provided by the bridge circuit. A resistor in the bridge circuit is selected such that the sense (control) signal provided by the bridge circuit has a rate of change as a function of flow rate substantially independent of fluid temperature, but this sense signal still varies as a function of fluid temperature. This permits fluid temperature compensation of the bridge sense signal in a noncomplex and cost effective manner.