05204814 is referenced by 293 patents and cites 20 patents.

Disclosed is an automatic, self propelled lawn mower that references its position within a cutting area using electronically stored path and terrain information as a primary navigation system, senses a non magnetic, non-current carrying metallic guide path as a secondary navigation system, senses underground metallic references for use as position reference points as a further navigation system, incorporates an ultrasonic obstacle detection system to stop the vehicle if unexpected obstacles are encountered. The vehicle further includes a cow-catcher front bumper arrangement to divert small objects away from the cutting blades, contains bumper switches to shut off the vehicle upon contact with large objects, contains an inclinometer sensor to halt the vehicle during unexpected tilting, incorporates a radio communications link to notify an off-board monitoring system of problems, contains an on-board power generation system using an internal combustion engine, generator, and a battery arrangement. The lawn mower also provides a navigation controller and servo motor positioning system that plans path motion, using sensory data and stored map data and to turn the drive wheels to propell the vehicle in the desired manner.

Title
Autonomous lawn mower
Application Number
7/611679
Publication Number
5204814
Application Date
November 13, 1990
Publication Date
April 20, 1993
Inventor
Barry Bryant
New Baltimore
MI, US
John Fisher
Avondale
PA, US
Thomas H Noonan
Havertown
PA, US
Agent
Sixbey Friedman Leedom & Ferguson
Assignee
Mobot
PA, US
IPC
B62D 1/28
G06F 15/50
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