US 5,204,814 A · Autonomous lawn mower

Abstract

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.

Claims28

Dependent claims

An autonomous lawn mower operative to self navigate along a prescribed path in accordance with stored route information compared with information from position markers spaced along the prescribed path comprising:

a body for supporting components of the lawn mower;
a power generation means supported by said body for supplying power to the lawn mower;
a plurality of wheels supporting said body;
at least one cutting means driven by said power generation means, with said cutting means extending below said body;
central processor means mounted on said body which includes stored route information including identity and position information indicative of the identity and position of said spaced position markers;
sensing means mounted on said body and operative to sense the presence of a position marker and the position of said position marker relative to said body, said sensing means being connected to said central processor means and operating to transmit a data signal to said central processor means when a position marker is sensed, said processor means operating in response to a data signal from said sensing means to compare said data signal with the stored identity and position information for said spaced position markers to determine an actual position, and
control means mounted on said body and connected to said central processor means for controlling the movement of the lawn mower along the prescribed path, said central processor means operating to provide a correction signal to said control means in response to a deviation of said actual position from the prescribed path, said control means operating to correct the travel of the lawn mower in response to a deviation signal.

4 more elements

An autonomous lawn mower operative to self navigate along a prescribed path in accordance with stored route information which includes terrain feature data comprising:

a body for supporting components of the lawn mower;
a power generation means supported by said body for supplying power to the lawn mower;
a plurality of wheels supporting said body;
central processor means mounted on said body which includes said stored route information;
and
control means mounted on said body and connected to said central processor means for controlling the movement of the lawn mower;
said central processor means operating in response to said stored terrain feature data to provide speed control signals to said control means, said control means operating in response to said speed control signals to vary the speed of said lawn mower in accordance with said stored terrain feature data.

4 more elements

Dependencies are inferred from the claim text.

Autonomous lawn mower

Life of this patent

Autonomous lawn mower

Life of this patent

Abstract

Claims28