METHOD AND SYSTEM FOR DETERMINING PRECISE ROBOTIC POSITION AND ORIENTATION USING NEAR-SIMULTANEOUS RADIO FREQUENCY MEASUREMENTS

• US 20160193729A1
• Filed: 01/06/2015
• Published: 07/07/2016
• Est. Priority Date: 01/06/2015
• Status: Active Grant

• Current Assignee: Nexus Robotics LLC
• Original Assignee: Discovery Robotics
• Inventors: WILLIAMS, Larry J.
• Granted Patent: US 9,722,640 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B25J 13/089 Determining the position of the robot with reference to its environment
• CPC Class Codes: B25J 5/007 mounted on wheels
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/3856 Data obtained from user input
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G05D 1/028 using a RF signal
• CPC Class Codes: H04B 1/0092 using a wideband front end
• CPC Class Codes: Y10S 901/01 Mobile robot

Abstract

A method and system for determining position and/or pose of an object. A robotic device moves throughout an environment and includes a master transceiver tag and, optionally, additional tags. The environment includes a plurality of anchor nodes that are configured to form a network. A master anchor node is in communication with at least a portion of the plurality of anchor nodes and is configured to transmit a ranging message as a UWB signal, receive a ranging message response from each other anchor node in the network, generate a reference grid representing physical locations of the plurality of anchor nodes within the network based upon the received ranging message responses, and distribute the reference grid to each of the other anchor nodes. The master transceiver tag receives the reference grid information and, based upon further calculations, determines a specific position and pose of the robotic device within the environment.

Claims

1. A method for establishing a reference grid and locating an object within the reference grid, the method comprising:

receiving, by at least one anchor node of a plurality of anchor nodes in a network, an indication that a selected anchor node is to function as a master anchor node;

transmitting, by the master anchor node, a ranging message as an ultra-wideband (UWB) signal;

receiving, by the master anchor node, a ranging message response from each other anchor node in the network;

generating, by the master anchor node, a reference grid representing physical locations of the plurality of anchor nodes within the network based upon the received ranging message responses; and

distributing, by the master anchor node, the reference grid to each of the other anchor nodes.

2. The method of claim 1, wherein generating a reference grid further comprises:

determining, by the master anchor node, a distance between each pair of anchor nodes;

establishing, by the master anchor node, a coordinate plane using at least three anchor nodes as edge defining points within the coordinate plane; and

mapping, by the master anchor node, each of the anchor points within the coordinate plane based upon trilateration information related to each of the anchor points.

3. The method of claim 2, wherein generating a reference grid further comprises:

identifying, by the master anchor node, a first closest anchor point, wherein the first closest anchor node is located at a position physically closest to the master anchor node within the network;

identifying, by the master anchor node, a second closest anchor point, wherein the second closest anchor node is located at a position physically second closest to the master anchor node within the network;

generating, by the master anchor node, a reference sample point midway between the first closest anchor node and the second closest anchor node;

creating, by the master anchor node, best fit position sets for at least a portion of the plurality of anchor nodes based upon the location of the reference sample point; and

generating, by the master anchor node, a refined reference grid based upon the best fit position sets.

4. The method of claim 1, further comprising:

receiving, by the master anchor node, an indication that at least one of the plurality of anchor nodes has received a request to join the network from a master transceiver tag associated with a robotic device; and

transmitting, by the master anchor node, distance information related to each of the plurality of anchor nodes to the master transceiver tag.

5. The method of claim 4, further comprising:

receiving, by the master transceiver tag, the distance information for each of the plurality of anchor nodes;

determining, by master the transceiver tag, a set of best fit anchor nodes based upon the distance information;

determining, by master the transceiver tag, ranging information from the transceiver tag to each of the set of best fit anchor nodes; and

calculating, by master the transceiver tag, a position of the robotic device based upon the determined ranging information.

6. The method of claim 5, further comprising:

receiving, by the master transceiver tag, relative positioning information from a plurality of additional transceiver tags operably attached to the robotic device;

calculating, by the master transceiver tag, a location for each of the plurality of additional transceiver tags based upon the received relative positioning information and the position of the robotic device; and

determining, by the master transceiver tag, a pose of the robotic device based upon the calculated location of each of the plurality of additional transceiver tags.

7. The method of claim 1, further comprising:

determining, by a transceiver tag associated with an input stylus, a current position of the input stylus;

transmitting, by the transceiver tag, the current position of the input stylus as it relates to the plurality of anchor nodes; and

transmitting, by the transceiver tag, updated position information for the stylus as it relates to the plurality of anchor nodes in response to the stylus being moved.

8. The method of claim 7, further comprising:

receiving, by a processing device associated with a mapping application, stylus position information from the stylus;

recording, by the processing device, a representation of the stylus position information as a digital map; and

updating, by the processing device, the digital map to reflect any updated stylus position information received from the stylus.

9. The method of claim 7, further comprising correlating, by a processing device associated with a mapping application, stylus position information as received from the stylus with recognizable points on an existing map to create an alternate digital map reflecting any updated stylus position information received from the stylus.

10. A method for determining a position of a robotic device within an environment, the method comprising:

transmitting, by a master transceiver tag associated with a robotic device, a request to join a network, the network comprising at least one master node and a plurality of anchor nodes;

receiving, by the master transceiver tag, distance information for at least a portion of the master node and the plurality of anchor nodes; and

determining, by the master transceiver tag, a physical location of the robotic device within the environment.

11. The method of claim 10, wherein the determining a physical location further comprises:

determining, by master the transceiver tag, a set of best fit anchor nodes based upon the distance information;

determining, by master the transceiver tag, ranging information from the transceiver tag to each of the set of best fit anchor nodes; and

calculating, by master the transceiver tag, a position of the robotic device based upon the determined ranging information.

12. The method of claim 11, further comprising:

receiving, by the master transceiver tag, relative positioning information from a plurality of additional transceiver tags operably attached to the robotic device;

calculating, by the master transceiver tag, a location for each of the plurality of additional transceiver tags based upon the received relative positioning information and the position of the robotic device; and

determining, by the master transceiver tag, a pose of the robotic device based upon the calculated location of each of the plurality of additional transceiver tags.

16. The system of claim 12, wherein the second set of instructions further comprises instructions that, when executed, cause the processing device of the master anchor node to:

receive an indication that at least one of the plurality of anchor nodes has received a request to join the network from a master transceiver tag associated with a robotic device; and

transmit distance information related to each of the plurality of anchor nodes to the master transceiver tag.

17. The system of claim 16, wherein the first set of instructions comprises instructions that, when executed, cause the processing device of the master transceiver tag to:

receive the distance information for each of the plurality of anchor nodes;

determine a set of best fit anchor nodes based upon the distance information;

determine ranging information from the transceiver tag to each of the set of best fit anchor nodes; and

calculate a position of the robotic device based upon the determined ranging information.

18. The system of claim 17, wherein the first set of instructions comprises instructions that, when executed, cause the processing device of the master transceiver tag to:

receive relative positioning information from a plurality of additional transceiver tags operably attached to the robotic device;

calculate a location for each of the plurality of additional transceiver tags based upon the received relative positioning information and the position of the robotic device; and

determine a pose of the robotic device based upon the calculated location of each of the plurality of additional transceiver tags.

19. The system of claim 12, further comprising a stylus comprising a stylus transceiver tag, the stylus transceiver tag comprising a processing device and a non-transitory computer readable medium operably connected to the processing device of the stylus transceiver tag and configured to store a third set of instructions that, when executed, cause the processing device of the stylus transceiver tag to:

determine a current position of the input stylus;

transmit the current position of the input stylus as it relates to the plurality of anchor nodes; and

transmit updated position information for the stylus as it relates to the plurality of anchor nodes in response to the stylus being moved.

20. The system of claim 19, further comprising a mapping system comprising:

a mapping processing device; and

a non-transitory computer readable medium operably connected to the mapping processing device and configured to store a mapping application, the mapping application comprising a fourth set of instructions that, when executed, cause the mapping processing device to;

receive stylus position information from the stylus,

record a representation of the stylus position information as a digital map, and

update the digital map to reflect any updated stylus position information received from the stylus.

13. A system for determining a location of a robotic device within an environment, the system comprising:

a robotic device configured to move throughout the environment, the robotic device comprising a master transceiver tag, the master transceiver tag comprising a processing device and a non-transitory computer readable medium operably connected to the processing device of the master transceiver tag and configured to store a first set of instructions; and

a plurality of anchor nodes located throughout the environment and configured to form a network; and

a user-selected master anchor node in communication with at least a portion of the plurality of anchor nodes, the master anchor node comprising a processing device and a non-transitory computer readable medium operably connected to the processing device of the master anchor node and configured to store a second set of instructions that, when executed, cause the processing device of the master anchor node to;

transmit a ranging message as an ultra-wideband (UWB) signal,

receive a ranging message response from each other anchor node in the network,

generate a reference grid representing physical locations of the plurality of anchor nodes within the network based upon the received ranging message responses, and

distribute the reference grid to each of the other anchor nodes.

14. The system of claim 13, wherein the second set of instructions for causing the master anchor node processing device to generate a reference grid further comprises instructions that, when executed, cause the processing device of the master anchor node to:

determine a distance between each pair of anchor nodes;

establish a coordinate plane using at least three anchor nodes as edge defining points within the coordinate plane; and

map each of the anchor points within the coordinate plane based upon trilateration information related to each of the anchor points.

15. The system of claim 14, wherein the second set of instructions for causing the master anchor node processing device to generate a reference grid further comprises instructions that, when executed, cause the processing device of the master anchor node to:

identify a first closest anchor point, wherein the first closest anchor node is located at a position physically closest to the master anchor node within the network;

identify a second closest anchor point, wherein the second closest anchor node is located at a position physically second closest to the master anchor node within the network;

generate a reference sample point midway between the first closest anchor node and the second closest anchor node;

create best fit position sets for at least a portion of the plurality of anchor nodes based upon the location of the reference sample point; and

generate a refined reference grid based upon the best fit position sets.