ADAPTIVE SCHEDULING OF A SERVICE ROBOT

• US 20110166701A1
• Filed: 01/06/2010
• Published: 07/07/2011
• Est. Priority Date: 01/06/2010
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Johnson, David August, Anderson, Noel Wayne, Eisenbeis, Kirk, Thacher, Russell, Hoffman, Joshua D.
• Granted Patent: US 8,295,979 B2
• Time in Patent Office: Days
• US Class Current: 700/245
• CPC Class Codes: A01B 79/005 Precision agriculture
• CPC Class Codes: A01D 34/008 for automated or remotely controlled operation
• CPC Class Codes: A01G 25/00 Watering gardens, fields, sports grounds or the like special apparatus or adaptations for fertilising-liquids A01C23/00; nozzles or outlets, spraying apparatus B05B

Abstract

A method for scheduling mowing tasks by a robotic mower is provided. An estimated height of grass cut by the robotic mower is determined for a predetermined number of past mowing tasks. The estimated height of grass cut is compared with a predicted height of grass in an operating environment for the robotic mower. Then, a mowing schedule for the robotic mower is adjusted by decreasing a time between mowing tasks in response to the estimated height of grass cut being greater than the predicted height of grass. Alternatively, the mowing schedule for the robotic mower is adjusted by increasing the time between mowing tasks in response to the estimated height of grass cut being less than the predicted height of grass.

Claims

1. A method for scheduling mowing tasks by a robotic mower, the method comprising:

determining an estimated height of grass cut by the robotic mower for a predetermined number of past mowing tasks;

comparing the estimated height of grass cut with a predicted height of grass in an operating environment for the robotic mower;

adjusting a mowing schedule for the robotic mower by decreasing a time between mowing tasks in response to the estimated height of grass cut being greater than the predicted height of grass; and

adjusting the mowing schedule for the robotic mower by increasing the time between mowing tasks in response to the estimated height of grass cut being less than the predicted height of grass.

2. The method of claim 1 further comprising:

estimating a height of grass cut during a current mowing task; and

recording the height of grass cut estimate for the current mowing task in a storage device.

3. The method of claim 1 further comprising:

mapping received environmental factors to past times in association with intervals between scheduled mowing tasks;

receiving current and future predictions of environmental factors; and

adjusting the mowing schedule for the robotic mower based on estimated grass height to account for the environmental factors.

4. The method of claim 1 further comprising:

receiving a power up command based on the mowing schedule for the robotic mower;

determining whether current environmental factors are adverse to performing a mowing task; and

responsive to determining that the current environmental factors are adverse to performing the mowing task, rescheduling the mowing task.

5. The method of claim 1 further comprising:

returning the robotic mower to a charging station, wherein a return to charging station behavior is activated at a first predetermined percentage charge level remaining in a rechargeable power source in the robotic mower, and wherein a target percentage charge level remaining in the rechargeable power source at return to the charging station is set at a second predetermined percentage charge level; and

wherein an actual percentage charge level remaining in the rechargeable power source at return to the charging station is determined; and

wherein the first predetermined percentage charge level for activating the return to charging station behavior is increased in response to the actual percentage charge level remaining in the rechargeable power source at return to the charging station being less than the target percentage charge level remaining in the rechargeable power source at return to the charging station.

6. The method of claim 5, wherein ambient air temperature data is used to adjust the first predetermined percentage charge level for activating the return to charging station behavior.

7. The method of claim 5, wherein topographic data regarding an operating environment for the robotic mower is used to adjust the first predetermined percentage charge level for activating the return to charging station behavior.

8. The method of claim 1, wherein the robotic mower is aware of an irrigation system watering schedule;

and wherein the mowing schedule is adjusted in response to changes to the irrigation system watering schedule.

9. The method of claim 1, wherein behavioral patterns of a user are used to adjust the mowing schedule;

and wherein the behavioral patterns of the user are retrieved from an electronic calendar application.

10. The method of claim 1, wherein the predicted height of grass is based on a grass growth model, and wherein the predicted height of grass is calculated prior to a mowing task.

11. The method of claim 1, wherein a boundary sensor that is used to identify a boundary wire of an operating environment for the robotic mower is also used to measure soil moisture.

12. The method of claim 1, wherein determining the estimated height of grass cut by the robotic mower is based on a power usage of a cutting unit motor in the robotic mower.

13. The method of claim 1, wherein determining the estimated height of grass cut by the robotic mower is based on data obtained by at least one of a grass height sensor and a structured light sensor.

14. A robotic mower comprising:

a cutting unit motor;

a propulsion system;

a steering system;

a braking system;

a sensor system for collecting data regarding an operating environment for the robotic mower;

a monitoring system that monitors a power usage of the cutting unit motor; and

a machine controller coupled to the cutting unit motor, the propulsion system, the steering system, the braking system, the sensor system, and the monitoring system;

wherein the machine controller determines an estimated height of grass cut by the robotic mower for a predetermined number of past mowing tasks, compares the estimated height of grass cut with a predicted height of grass in an operating environment for the robotic mower, adjusts a mowing schedule for the robotic mower by decreasing a time between mowing tasks in response to the estimated height of grass cut being greater than the predicted height of grass, and adjusts the mowing schedule for the robotic mower by increasing the time between mowing tasks in response to the estimated height of grass cut being less than the predicted height of grass.

15. The robotic mower of claim 14, wherein the machine controller estimates a height of grass cut during a current mowing task and records the height of grass cut estimate for the current mowing task in a storage device.

16. The robotic mower of claim 14, wherein the machine controller maps received environmental factors to past times in association with intervals between scheduled mowing tasks, receives current and future predictions of environmental factors, and adjusts the mowing schedule for the robotic mower based on estimated grass height to account for the environmental factors.

17. The robotic mower of claim 14, wherein the machine controller receives a power up command based on the mowing schedule for the robotic mower, determines whether current environmental factors are adverse to performing a mowing task, and reschedules the mowing task in response to determining that the current environmental factors are adverse to performing the mowing task.

18. The robotic mower of claim 14, wherein the machine controller returns the robotic mower to a charging station;

and wherein the machine controller activates a return to charging station behavior at a first predetermined percentage charge level remaining in a rechargeable power source in the robotic mower; and

wherein the machine controller sets a target percentage charge level remaining in the rechargeable power source at return to the charging station at a second predetermined percentage charge level; and

wherein the machine controller determines an actual percentage charge level remaining in the rechargeable power source at return to the charging station; and

wherein the machine controller increases the first predetermined percentage charge level for activating the return to charging station behavior in response to the actual percentage charge level remaining in the rechargeable power source at return to the charging station being less than the target percentage charge level remaining in the rechargeable power source at return to the charging station.

19. The robotic mower of claim 18, wherein the machine controller uses ambient air temperature data to adjust the first predetermined percentage charge level for activating the return to charging station behavior.

20. The robotic mower of claim 18, wherein the machine controller uses topographic data regarding the operating environment for the robotic mower to adjust the first predetermined percentage charge level for activating the return to charging station behavior.