Autonomous lawnmower

• US 10,705,533 B1
• Filed: 08/18/2008
• Issued: 07/07/2020
• Est. Priority Date: 05/31/2005
• Status: Active Grant

• Current Assignee: Richard Anthony Bishel, Wilson G. Gregory
• Original Assignee: Richard Anthony Bishel, Wilson G. Gregory
• Inventors: Bishel, Richard Anthony, Wilson, G. Gregory
• Primary Examiner(s): To, Tuan C
• Assistant Examiner(s): Castro, Paul A
• Application Number:
  US12/228,969
• Time in Patent Office: 4,341 Days
• Field of Search: 56 102 D, 56 102 E, 56 102 F, 56 102 A, 73862, 192125 R, 192125 E, 180401
• CPC Class Codes: G05D 1/0231 using optical position detecting means position-fixing by using electromagnetic waves other than radio waves, e.g. optical position detecting means G01S5/16
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93

Abstract

A semi-autonomous or autonomous mowing vehicle with a sensor that detects the boundary between a first, relatively higher surface, such as the un-mowed vegetation and a second, a relatively lower surface, such as the mowed vegetation, and a controller for steering the semi-autonomous or autonomous vehicle along detected boundary. The detected boundary is based on height differential between the two surfaces and two methods are discussed. For one, the boundary between the two surfaces is detected using a plurality of non-contact distance measuring sensors aligned in same direction, and processes these distance measuring sensors for determining the distance sensors that measure said first relatively higher surface and the distance sensors that measure the second relatively lower surface. For two, the boundary between the two surfaces is detected using a plurality of rotatable contact members on a rotating shaft and a plurality of slip clutches, each slip clutch associated with each contact member coupling the shaft to the contact member in rotating engagement, and processes the internal sensors for detecting impeded rotation of said contact members do to slippage of said clutches in response to contact with said first surface, relatively higher surface, but not contact with said second surface, a relatively lower surface.

Claims

1. A guidance apparatus for a semi-autonomous or autonomous vehicle, the guidance apparatus comprising:

a plurality of non-contacting distance sensors, wherein said sensors are infrared, ultrasonic, capacitance, microwave, or vision, spaced closely together with no moving components directly above two surfaces with a boundary between the two surfaces, wherein the two surfaces comprise a first, relatively higher surface and a second, relatively lower surface, wherein each distance sensor is fixed in a physical orientation with respect to the vehicle and configured to detect the boundary between the two surfaces without movement of the vehicle by measuring a first vertical distance from some of the distance sensors to the first surface and by measuring a second vertical distance from some of the distance sensors to the second surface; and

a controller electrically connected to the plurality of non-contacting distance sensors and configured to produce one or more guidance signals for said semi-autonomous or autonomous vehicle to steer said semi-autonomous or autonomous vehicle along said boundary detected by said plurality of non-contacting distance sensors.

2. The apparatus of claim 1, wherein the plurality of non-contacting distance sensor comprises:

a plurality of non-contact distance measuring sensors aligned in a same direction with each sensor having a transmitter and a receiver; and

a processor electrically connected to the plurality of non-contacting distance measuring sensors and configured to determine which of said non-contacting distance measuring sensors measure said first, relatively higher surface and which of said non-contacting distance measuring sensors measure said second, relatively lower surface.

3. The apparatus of claim 1, wherein the first, relatively higher surface is associated with un-mowed vegetation.

4. The apparatus of claim 1, wherein the second, relatively lower surface is associated with mowed vegetation.

5. The apparatus of claim 1, wherein the second, relatively lower surface is a flower bed, a sidewalk, a barrier, or a lower border.

6. The apparatus of claim 1, wherein the controller is one or more of a microcontroller or an integrated circuit.

7. A guidance apparatus for a semi-autonomous or autonomous vehicle, the guidance apparatus comprising:

a plurality of rotatable contact members on a rotating shaft;

a plurality of slip clutches, each slip clutch associated with a contact member coupling said shaft to said contact member in rotating engagement;

a sensor configured to detect a boundary by detecting impeded rotation of said rotatable contact members relative to said rotating shaft due to slippage of one or more of said slip clutches in response to contact with a relatively higher surface, but not contact with a relatively lower surface, without stoppage of the said rotating shaft; and

a controller configured to produce one or more guidance signals to steer said semi-autonomous or autonomous vehicle along said boundary detected by said sensor.

8. A semi-autonomous or autonomous mowing vehicle having a body and at least one cutting blade under said body, the mowing vehicle comprising:

a plurality of non-contacting distance sensor, wherein said sensors are infrared, ultrasonic, capacitance, microwave, or vision, spaced closely together with no moving components directly above two surfaces with a boundary between the two surfaces, wherein the two surfaces comprise a first, relatively higher surface and a second, relatively lower surface, wherein each distance sensor is fixed in a physical orientation with respect to the vehicle and configured to detect the boundary without movement of the vehicle by measuring a first vertical distance from some of the distance sensors to the first surface and by measuring a second vertical distance from some of the distance sensors to the second surface; and

a controller electrically connected to the plurality of non-contacting distance sensors and configured to produce one or more guidance signals to steer said mowing vehicle along said boundary.

9. The mowing vehicle of claim 8, wherein the plurality of non-contacting distance sensors comprise:

a plurality of non-contact distance-measuring sensors aligned in a same direction with each sensor having a transmitter and a receiver; and

a processor electrically connected to the plurality of non-contact distance-measuring sensors and configured to determine which of said non-contact distance-measuring sensors measure said first, relatively higher surface and which of said non-contact distance-measuring sensors measure said second, relatively lower surface.

10. The mowing vehicle of claim 8, wherein the first, relatively higher surface is associated with un-mowed vegetation.

11. The mowing vehicle of claim 8, wherein the second, relatively lower surface is associated with mowed vegetation.

12. The mowing vehicle of claim 8, wherein the second, relatively lower surface is one of a flower bed, a sidewalk, a barrier, or a lower border.

13. The mowing vehicle of claim 8, wherein the controller is one or more of a microcontroller or an integrated circuit.

14. The mowing vehicle of claim 8, wherein said non-contacting distance sensors are integrated with a GPS, DGPS, vision, compass, gyroscope, or other sensor to determine the boundary when a gap in the boundary is present.

15. A semi-autonomous or autonomous mowing vehicle having a body and at least one cutting blade under said body, the mowing vehicle comprising:

a plurality of rotatable contact members on a rotating shaft;

a plurality of slip clutches, each slip clutch associated with one of said rotatable contact members, thereby coupling said shaft to a contact member in rotating engagement;

a sensor configured to detect impeded rotation of said rotatable contact members relative to said rotating shaft due to slippage of said clutches in response to contact with a first, relatively higher surface, but not contact with a second, relatively lower surface without stoppage of the rotating shaft; and

a controller configured to produce one or more guidance signals to steer said mowing vehicle along said boundary.

16. A method for controlling steering of a vehicle having at least one cutting blade for mowing a field, the method comprising:

measuring, with distance sensors, wherein said sensors are infrared, ultrasonic, capacitance, microwave, or vision, spaced closely together with no moving components that are fixed in a physical orientation with respect to the vehicle, a plurality of vertical distances directly above the vegetation to an approximate top of vegetation in the field so as to result in a respective plurality of measured distances,

wherein the plurality of vertical distances comprise a first vertical distance to a relatively higher top level of the vegetation and a second vertical distance to a relatively lower top level of the vegetation, wherein the relatively higher top level is associated with un-mowed vegetation, and the relatively lower top level is associated with mowed vegetation, and

wherein the plurality of measured distances are measured at points having known relative positions in a direction that is transverse to the direction of the distances and also generally transverse to a direction in which the vehicle is configured to move across the field during mowing,

wherein measuring the plurality of vertical distances is accomplished without contacting the vegetation and comprises transmitting a respective plurality of distance-measuring signals and estimating respective distances based on processing of the distance-measuring signals;

determining, based on the plurality of distances and the known relative positions of the points of distance measurement, an approximate boundary without movement of the vehicle between mowed vegetation and unmowed vegetation; and

controlling said vehicle to steer said vehicle based on said boundary.

17. The method of claim 16, wherein the vehicle comprises a plurality of non-contact distance measuring sensors aligned in same direction, wherein each distance measuring sensor has its own transmitting source and receiving source.