METHOD AND APPARATUS FOR OFFBOARD NAVIGATION OF A ROBOTIC DEVICE

• US 20160109883A1
• Filed: 06/25/2013
• Published: 04/21/2016
• Est. Priority Date: 06/03/2013
• Status: Abandoned Application

• Current Assignee: CtrlWorks Pte Ltd
• Original Assignee: CtrlWorks Pte Ltd
• Inventors: Sim, Kai, Cheng, Calvin
• Application Number:
  US14/895,347
• Publication Number:
  US 20160109883A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 5/0244 Accuracy or reliability of position solution or of measurements contributing thereto
• CPC Class Codes: G01S 5/0264 at least one of the systems being a non-radio wave positioning system
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/0282 generated in a local control room

Abstract

There is provided a method and apparatus for offboard navigation of a 5 robotic device. The method comprising defining a threshold value of a positional accuracy of the robotic device, calculating latency of a network through which the robotic device and a server communicate, the latency of the network being a difference between sending sensor data from the robotic device to the server and receiving processed data corresponding to the 10 sent sensor data by the robotic device from the server, and determining speed of the robotic device based on the threshold value of the positional accuracy of the robotic device and the latency of the network.

Claims

1. A method for offboard navigation of a robotic device, the method comprising:

defining a threshold value of a positional accuracy of the robotic device;

calculating latency of a network through which the robotic device and a server communicate, the latency of the network being a difference between sending sensor data from the robotic device to the server and receiving processed data corresponding to the sent sensor data by the robotic device from the server; and

determining speed of the robotic device based on the threshold value of the positional accuracy of the robotic device and the latency of the network.

2. The method according to claim 1, wherein determining the speed of the robotic device comprises setting a sampling period in accordance to the latency of the network, the sampling period being a difference between two consecutive sendings of the sensor data from the robotic device to the server.

3. The method according to claim 2, wherein determining the speed of the robotic device further comprises determining a commanded displacement to be moved by the robotic device in the sampling period.

4. The method according to claim 3, wherein determining the commanded displacement to be moved by the robotic device in the sampling period comprises determining a desired displacement to be moved by the robotic device in the sampling period according to characteristics of odometry error of the robotic device and obtaining a positional error to be offset in the sampling period.

5. The method according to claim 4, wherein the characteristics of the odometry error of the robotic device is represented by a profile curve of the odometry error of the robotic device calibrated in advance.

6. The method according to claim 1, wherein the threshold value of the positional accuracy of the robotic device is determined based on the environment in which the robotic device operates.

7. The method according to claim 1, wherein the speed of the robotic device is determined to be inversely proportional to the latency of the network.

8. The method according to claim 1 further comprising driving the robotic device to move at a speed equal to or less than the determined speed.

9. An apparatus for offboard navigation, the apparatus comprising:

a server; and

a robotic device configured to move according to navigation command received from the server;

the robotic device comprising;

sensors configured to obtain sensor data;

an interface configured to receive a threshold value of a positional accuracy of the robotic device; and

a processor configured to;

calculate latency of a network through which the robotic device and the server communicate, the latency of the network being a difference a difference between sending sensor data from the robotic device to the server and receiving processed data corresponding to the sent sensor data by the robotic device from the server; and

determine speed of the robotic device based on the threshold value of the positional accuracy of the robotic device and the latency of the network.

10. The apparatus according to claim 9, wherein the robotic device further comprises an odometer configured to estimate the position of the robotic device.

11. The apparatus according to claim 9, wherein the server is configured to process the sensor data sent from the robotic device to obtain positional information of the robotic device corresponding to the sent sensor data and send the positional information to the robotic device.

12. The apparatus according to claim 9, wherein the processor is further configured to:

set a sampling period in accordance to the latency of the network, the sampling period being a difference between two consecutive sendings of the sensor data from the robotic device to the server; and

determine a commanded displacement to be moved by the robotic device in the set sampling period.

13. The apparatus according to claim 12, wherein the processor is further configured to determine a desired displacement to be moved by the robotic device in the sampling period according to characteristics of odometry error of the robotic device and obtain a positional error to be offset in the sampling period to determine the commanded displacement to be moved as the desired displacement to be moved offset by the positional error.

14. The apparatus according to claim 13, wherein the characteristics of the odometry error of the robotic device is represented by a profile curve of the odometry error of the robotic device calibrated in advance.

15. The apparatus according to claim 9, wherein the threshold value of the position accuracy of the robotic device is determined based on the environment in which the robotic device operates.

16. The apparatus according to claim 9, wherein the speed of the robotic device is determined to be inversely proportional to the latency of the network.

17. The apparatus according to claim 9, wherein the robotic device is driven to move at a speed equal to or less than the determined speed.