US 10,539,967 B2Granted

GPS-free robots

AssigneeKing Fahd University of Petroleum and Minerals

InventorsUthman Baroudi, Gamal Sallam, Mohammed Al-Shaboti

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Abstract

A Two-hop Cooperative Virtual Force Robot Deployment (Two-hop COVER) technique is described. An improved Virtual force VF approach considers the mission requirements such as the number of required robots in each locality. The Two-hop COVER expedites the deployment process by establishing a cooperative relation between robots and neighboring landmarks. Two-hop cooperation is utilized as well to reduce the time and distance needed to satisfy mission requirements. In order to reduce randomness and guide remaining robots throughout the area till they find an unsatisfied landmark, each robot utilizes its history to visit only the locations that it has not visited before. Moreover, each robot will communicate with its neighboring robots and landmarks to use their current positions and history to guide its movements.

Claims20

Dependent claims

A method for mobile robot deployment based on two-hop cooperative virtual force, a plurality of mobile robots and a plurality of fixed landmarks that are in a region, the fixed landmarks each having a demand for a number of robots, the method comprising:

initially dropping the plurality of mobile robots at respective initial points in the region;
using virtual force, moving one or more of the plurality of mobile robots to a new position over the region, wherein, prior to each move, each of the one or more of the plurality of mobile robots remain in a current position for a predetermined period to collect messages from other ones of the plurality of mobile robots or one or more of the fixed landmarks, wherein each of the plurality of mobile robots is either an associated mobile robot that is associated with one of the fixed landmarks or an unassociated mobile robot that is not associated with one of the fixed landmarks;
for each unassociated mobile robot:
for messages collected from one or more other unassociated mobile robots, the unassociated mobile robot computes either an attractive force or a repulsive force depending on a distance from the unassociated mobile robot to a source robot, wherein the attractive force is a virtual force that attracts the unassociated mobile robot toward the source robot and the repulsive force is a virtual force that repels the unassociated mobile robot away from the source robot;
for messages collected from one or more of the fixed landmarks or associated mobile robots, the fixed landmarks or other associated mobile robots collaborate with any fixed landmarks whose demand has not been satisfied;
while remaining in the current position for the predetermined period, the unassociated mobile robot sends an association message to a nearest fixed landmark;
the nearest fixed landmark replies with a confirmation message or a rejection message;
maintaining the unassociated mobile robot in the current position on receipt of a confirmation message, and remaining at the current positions until the unassociated mobile robot determines that no neighboring fixed landmarks have a demand or the predetermined period elapses;
when the unassociated mobile robot receives a rejection message, the unassociated mobile robot contacts a next fixed landmark in a list of fixed landmarks;
and
when the unassociated mobile robot fails to associate to any unsatisfied fixed landmark, the unassociated mobile robot proceeds by computing a composite virtual force, and, when neighboring robots are not associated with any fixed landmark, the unassociated mobile robot moves based on the composite virtual force with respect to the neighboring robots,
wherein the plurality of mobile robots is deployed until the demand for the number of robots of each fixed landmark is satisfied.

9 more elements

A system for mobile robot deployment based on two-hop cooperative virtual force, a plurality of mobile robots and a plurality of fixed landmarks that are in a region, the fixed landmarks each having a demand for a number of robots, the system comprising:

initially dropping the plurality of mobile robots at respective initial points in the region;
using virtual force, moving one or more of the plurality of mobile robots to a new position over the region, wherein, prior to each move, each mobile robot of the one or more mobile robots remains in a current position for a predetermined period to collect messages from other mobile robots or one or more of the fixed landmarks, wherein each of the plurality of mobile robots is either an associated mobile robot that is associated with one of the fixed landmarks or an unassociated mobile robot that is not associated with one of the fixed landmarks;
for each unassociated mobile robot:
for the messages collected from the one or more mobile robots that are not associated with any fixed landmarks, the unassociated mobile robot computes either an attractive force or a repulsive force depending on a distance from the unassociated mobile robot to a source robot, wherein the attractive force is a virtual force that attracts the unassociated mobile robot toward the source robot and the repulsive force is a virtual force that repels the unassociated mobile robot away from the source robot;
for the messages collected from one or more of the fixed landmarks or other ones of the one or more mobile robots that are already associated, the fixed landmarks or other associated mobile robots collaborate with other fixed landmarks whose demand has not been satisfied;
while remaining in the current position for the predetermined period, the unassociated mobile robot sends an association message to a nearest fixed landmark;
the nearest fixed landmark replies with a confirmation message or a rejection message;
maintaining the unassociated mobile robot in the current position on receipt of a confirmation message, and remaining at the current positions until the unassociated mobile robot determines that no neighboring fixed landmarks have a demand or the predetermined period elapses;
when the unassociated mobile robot receives a rejection message, the unassociated mobile robot contacts a next fixed landmark in a list of fixed landmarks;
and
when the unassociated mobile robot fails to associate to any unsatisfied fixed landmark, the unassociated mobile robot proceeds by computing a composite virtual force, wherein when neighboring mobile robots are not associated with any fixed landmark, the unassociated mobile robot moves based on the composite virtual force with respect to the neighboring robots,
wherein the plurality of mobile robots is deployed until the demand for the number of robots of each fixed landmark is satisfied.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/684,373Filed 23 Aug 2017 · us provisional application
Priority: 23 Aug 2016
Published: US 2018/0059685 A11 Mar 2018
Granted: 21 Jan 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

G05D 1/0287
Specially adapted to land vehicles: involving a plurality of land vehicles, e.g. fleet or convoy travelling
G05D 1/028
Using signals provided by a source external to the vehicle: using a RF signal
G05D
Systems for controlling or regulating non-electric variables