Fixed segmented lattice planning for a mobile automation apparatus

• US 10,591,918 B2
• Filed: 05/01/2017
• Issued: 03/17/2020
• Est. Priority Date: 05/01/2017
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Inventors: Jen, Kevin C., Singh, Harsoveet, Smith, Stephen L.
• Primary Examiner(s): Hutchinson, Alan D
• Application Number:
  US15/583,773
• Publication Number:
  US 20180314260A1
• Time in Patent Office: 1,051 Days
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• CPC Class Codes: G05D 1/0094 involving pointing a payload, e.g. camera, weapon, sensor, towards a fixed or moving target
• CPC Class Codes: G05D 1/0212 with means for defining a desired trajectory involving a plurality of land vehicles G05D1/0287
• CPC Class Codes: G05D 1/0214 in accordance with safety or protection criteria, e.g. avoiding hazardous areas monitoring the location of vehicles within a certain area, e.g. forbidden or allowed areas, in traffic control systems for road vehicles G08G1/13
• CPC Class Codes: G05D 1/0221 involving a learning process
• CPC Class Codes: G05D 1/0274 using mapping information stored in a memory device navigation using map-matching G01C21/30
• CPC Class Codes: G05D 1/0276 using signals provided by a source external to the vehicle involving a plurality of vehicles G05D1/0287; automatically controlling vehicle speed responsive to externally generated signals B60K31/0058
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks

Abstract

Fixed segmented lattice planning for a mobile automation apparatus is provided. A mobile automation apparatus is provisioned with a plurality of segments for a plurality of paths through an environment, each of the plurality of segments being fixed in a reference frame, the plurality of segments arranged in a lattice configuration, with adjacent segments defining fixed nodes in the lattice configuration. The apparatus navigates through the environment on a segment-by-segment basis, storing control inputs and error signals for each segment and then later, when again navigating a segment using stored control inputs and error signals to generate current control inputs, along with current error signals, and storing the current control inputs and the current error signals. Indeed, each time the apparatus navigates a segment in the lattice configuration, the control inputs and the error signals are updated to refine navigation through the environment at each navigation through a segment.

Claims

1. A mobile automation apparatus comprising:

a memory storing a plurality of segments for a plurality of paths through an environment, each of the plurality of segments being fixed in a reference frame and extending between fixed nodes arranged in a lattice configuration;

a navigation module having at least one motor configured to move the mobile automation apparatus in the environment; and

a navigation controller configured to;

as navigation occurs a first time along each of respective segments using the navigation module, store, in the memory, control inputs and error signals for the navigation module in association with each of the respective segments;

as navigation occurs at least a second time along a given segment;

generate current control inputs for the given segment based on current error signals and the control inputs and the error signals stored in the memory for the given segment; and

store the current control inputs and the current error signals in the memory in association with the given segment,

wherein the controller is further configured to generate branches at each fixed node in a path, each of the branches associated with a set of respective control inputs used by the navigation module to navigate from a respective fixed node in the path to one or more fixed nodes in adjacent paths.

2. The mobile automation apparatus of claim 1, further comprising one or more obstacle avoidance sensors, wherein the navigation controller is further configured to:

navigate along a first path using the control inputs and the error signals stored in the memory in association with each of the respective segments of the first path;

when an obstacle is detected in the first path, using the one or more obstacle avoidance sensors;

control the navigation module to navigate from a fixed node in the first path to a respective fixed node in a second path to avoid the obstacle, using a branch from the fixed node in the first path to the respective fixed node in the second path; and

store, in the memory, the control inputs and the error signals for the navigation module in association with each of the respective segments for the second path; and

,

when the one or more obstacle avoidance sensors indicate that the mobile automation apparatus is past the obstacle;

control the navigation module to navigate from a further respective fixed node in the second path to a further fixed node in the first path, using another branch from the further respective fixed node in the second path to the further fixed node in the first path; and

store, in the memory, the control inputs and the error signals for the navigation module in association with each of the respective segments for the second path and the first path.

3. The mobile automation apparatus of claim 2, wherein the second path is one or more of:

adjacent to the first path;

parallel to the first path; and

within a given constraint boundary.

4. The mobile automation apparatus of claim 1, further comprising a communication interface configured to receive a destination position in the environment, and wherein the navigation controller is further configured to:

generate the path to the destination position using a subset of the plurality of segments.

5. The mobile automation apparatus of claim 1, wherein the navigation controller is further configured to:

generate branches at each fixed node in the path when the path is generated.

6. The mobile automation apparatus of claim 1, wherein the navigation controller is further configured to:

determine the control inputs and the error signals for the navigation module using a learning controller; and

generate the current control inputs using the learning controller.

7. The mobile automation apparatus of claim 1, wherein the navigation controller is further configured to:

determine when one or more constraints for navigating the given segment has been violated; and

generate the current control inputs that keep the one or more constraints within respective threshold values.

8. The mobile automation apparatus of claim 1, wherein the navigation controller is further configured to change the path when one or more constraints for navigating the respective segments have been violated by navigating along an updated path that meets the one or more constraints.

9. The mobile automation apparatus of claim 1, wherein the reference frame is associated with the environment.

10. The mobile automation apparatus of claim 1, wherein the lattice configuration comprises the fixed nodes arranged in a periodic pattern in at least two orthogonal directions according to a given resolution.

11. The mobile automation apparatus of claim 1, wherein the lattice configuration has a first resolution in a first region of the environment and a second resolution in a second region of the environment.

12. The mobile automation apparatus of claim 1, wherein a resolution of the lattice configuration is dynamic, and the navigation controller is further configured to:

change the resolution of the lattice configuration in a region to an updated resolution, and generate new control inputs and determine associated new error signals for each of updated segments in the lattice configuration at the updated resolution.

13. A method comprising:

at a mobile automation apparatus comprising;

a memory storing a plurality of segments for a plurality of paths through an environment, each of the plurality of segments being fixed in a reference frame and extending between fixed nodes arranged in a lattice configuration;

a navigation module having at least one motor configured to move the mobile automation apparatus in the environment, as navigation occurs a first time along each of respective segments using the navigation module, storing, using the navigation controller, in the memory, control inputs and error signals for the navigation module in association with each of the respective segments;

as navigation occurs at least a second time along a given segment;

generating, using the navigation controller, current control inputs for the given segment based on current error signals and the control inputs and the error signals stored in the memory for the given segment;

storing, using the navigation controller, the current control inputs and the current error signals in the memory in association with the given segment; and

generating branches at each fixed node in a path, each of the branches associated with a set of respective control inputs used by the navigation module to navigate from a respective fixed node in the path to one or more fixed nodes in adjacent paths.

14. The method of claim 13, wherein the mobile automation apparatus further comprises one or more obstacle avoidance sensors, and the method further comprises:

navigating, using the navigation controller, along a first path using the control inputs and the error signals stored in the memory in association with each of the respective segments of the first path;

when an obstacle is detected in the first path, using the one or more obstacle avoidance sensors;

controlling, using the navigation controller, the navigation module to navigate from a fixed node in the first path to a respective fixed node in a second path to avoid the obstacle, using a branch from the fixed node in the first path to the respective fixed node in the second path; and

storing, using the navigation controller, in the memory, the control inputs and the error signals for the navigation module in association with each of the respective segments for the second path; and

,

when the one or more obstacle avoidance sensors indicate that the mobile automation apparatus is past the obstacle;

controlling, using the navigation controller, the navigation module to navigate from a further respective fixed node in the second path to a further fixed node in the first path, using another branch from the further respective fixed node in the second path to the further fixed node in the first path; and

storing, using the navigation controller, in the memory, the control inputs and the error signals for the navigation module in association with each of the respective segments for the second path and the first path.

15. The method of claim 13, wherein the mobile automation apparatus further comprises a communication interface configured to receive a destination position in the environment, and wherein the method further comprises generating, using the navigation controller, the path to the destination position using a subset of the plurality of segments.

16. The method of claim 13, further comprising:

determining the control inputs and the error signals for the navigation module using a learning controller; and

generating the current control inputs using the learning controller.

17. The method of claim 13, further comprising:

determining when one or more constraints for navigating the given segment has been violated; and

generating the current control inputs that keep the one or more constraints within respective threshold values.

18. A non-transitory computer-readable medium storing a computer program, wherein execution of the computer program is for:

at a mobile automation apparatus comprising;

a memory storing a plurality of segments for a plurality of paths through an environment, each of the plurality of segments being fixed in a reference frame and extending between fixed nodes arranged in a lattice configuration;

a navigation module having at least one motor configured to move the mobile automation apparatus in the environment, as navigation occurs a first time along each of respective segments using the navigation module, storing, using the navigation controller, in the memory, control inputs and error signals for the navigation module in association with each of the respective segments;

as navigation occurs at least a second time along a given segment;

generating, using the navigation controller, current control inputs for the given segment based on current error signals and the control inputs and the error signals stored in the memory for the given segment;

storing, using the navigation controller, the current control inputs and the current error signals in the memory in association with the given segment; and

generating branches at each fixed node in a path, each of the branches associated with a set of respective control inputs used by the navigation module to navigate from a respective fixed node in the path to one or more fixed nodes in adjacent paths.