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EP-4736504-A1 - METHOD OF CREATING WIRELESS AD HOC NETWORK IN COMMUNICATION-DENIED ENVIRONMENTS USING ROBOTIC SYSTEMS AND THE NETWORK CREATED BY THIS METHOD

EP4736504A1EP 4736504 A1EP4736504 A1EP 4736504A1EP-4736504-A1

Abstract

A method of creating wireless ad hoc network in communication-denied environments using robotic systems. The method comprises step of using a robotic system configured to carry a plurality of communication nodes to deploy one node at the starting point suitable for entering the area where the network shall be established. Further, the method comprises navigating the mobile robotic vehicle to following point to deploy static node or dynamic node, while upon navigating to this following point, checking that the distance from this following point to any of the preceding node(s) deployed does not extend the range in which the signal from any of the preceding node(s) is secured to establish the wireless connection through any of those preceding node(s). The method is carried out by repeating the second step until reaching the final destination point of the network and deploying the node to establish the wireless communication in the selected area. The invention also relates to a wireless ad hoc network created by this method. The network utilizes the flood routing approach and constrained randomized broadcasts to propagate messages through the ad hoc network. Such network is particularly suitable for controlling mobile robotic vehicles, in particular in multi-robot teaming in an autonomous exploration in communication-denied environments.

Inventors

  • Í EK, Petr
  • Faigl, Jan

Assignees

  • Ceské Vysoké Ucení Technické V Praze

Dates

Publication Date
20260506
Application Date
20230628

Claims (9)

  1. 1. A method of creating wireless ad hoc network in communication-denied environments using robotic systems, characterized in that it comprises following steps: A) using a robotic system configured to carry a plurality of communication nodes comprising at least three nodes adapted to receive and retransmit received message to establish wireless communication, such nodes further defined as static nodes, of which at least one node is actively emanating messages into the network according to defined transmission schedule, such node further defined as dynamic node, to deploy one node at the starting point suitable for entering the area where the network shall be established; B) navigating the mobile robotic vehicle to following point to deploy static node or dynamic node, while upon navigating to this following point, checking that the distance from this following point to any of the preceding node(s) deployed does not extend the range in which the signal from any of the preceding node(s) is secured to establish the wireless connection through any of those preceding node(s); C) repeating step B) until reaching the final destination point of the network and deploying the node to establish the wireless communication in the selected area.
  2. 2. The method according to claim 1, wherein in step B), checking the range in which the signal from any of the preceding nodes is secured is performed by sending control messages through the network and/or by computing the estimated safe communication range between the node to be deployed and any of the preceding deployed nodes.
  3. 3. The method according to claim 1 or 2, wherein in step B), navigating the robotic system to the point where communication interference with at least a plurality of previously deployed nodes is avoided and deploying the static node and/or dynamic node at such point.
  4. 4. The method according to any of claims 1 to 3, wherein the nodes are power activated during their deployment using the electro-magnetical principle.
  5. 5. The method according to any of claims 1 to 4, wherein the steps are carried out using an unmanned aerial vehicle UAV and/or unmanned ground vehicle UGV and/or unmanned underwater vehicle UUV.
  6. 6. A wireless ad hoc network, characterized in that it is created using the method according to any of claims 1 to 5.
  7. 7. The wireless ad hoc network according to claim 6, wherein it comprises . nodes consisting of a transmitter, transmitting messages over a wireless medium; . a receiver, receiving messages over said wireless medium; . a local message processor, coupled with said receiver, maintaining the message queue of received and retransmited messages; . a local stochastic schedule processor coupled with said transmiter and receiver, said local stochastic schedule processor maintaining and retransmiting received messages, capable of retransmiting received messages according to defined stochastic schedule; . nodes that emanate messages into the network according to the defined schedule; . with minimum of three nodes, out of which at least one node emanates the messages into the network;
  8. 8. The wireless ad hoc network according to claim 6 or 7, wherein the communication between the nodes employs use of message-based broadcast- enabled wireless signal where the packet size is selected according to the used transport signal and underlying technology and wherein each node maintains a list of messages that have been transmitted for a given time period which are limited in size and wherein the messages contain identifying data fields reserved for the identification of the message.
  9. 9. Use of the wireless ad hoc network according to any of claims 6 to 8 for controlling mobile robotic vehicles, in particular in multi-robot teaming in an autonomous exploration.

Description

Title: Method of creating wireless ad hoc network in communication-denied environments using robotic systems and the network created by this method TECHNICAL FIELD [0001] The present invention relates to the field of wireless communication systems, specifically to a Method of creating wireless ad hoc network in communication-denied environments using robotic systems and the network created by this method and the deployable wireless ad hoc network system with dynamic topology designed for multirobot systems in communication-denied environments without physical communication or wireless infrastructure, such as non-trivial underground and complex subterranean environment. BACKGROUND ART [0002] Communication is crucial in multi-robot systems, enabling efficient coordination and cooperation among team members. However, environments without existing communication infrastructure, such as underground caves, mines, or tunnels, necessitate developing rapidly deployable wireless network solutions to maintain situational awareness among multi-robot teams representing communication networks with highly dynamic topology. [0003] The following patent documents represent the known solutions related to this invention. Document EP1480387A1 describes an ad hoc communication network protocol using an ad hoc network coordinator, locally stored complete communication routes, and identification of other devices for message forwarding. The solution relies on the network topology with a network controller that controls a web of network devices, thus requiring a dedicated node coordinating the routing. [0004] The routing is based on incremental source routing, where the address field within the message might increase and thus limit a payload part of the communication message in packet-driven communication networks with minimal data payloads, such as IEEE 802.15.4 2006. [0005} An explicit network coordinator might be replaced by the so-called flooding routing in an ad hoc multicast network described in the document EP2068500A2. However, the role of the communication node is determined dynamically, and each node needs to include a local topology processor, network topology processor, and local multicast processor. The network topology processor maintains network topology databases or routing tables for establishing dedicated backbone routing links. The multicast processor is designed for the role of a supernode to maintain the backbone multicast registration table. [0006] Resource demands on the nodes can be decreased by flood-relaying, which requires low computational power and memory requirements. Hybrid flood-relying and routing are presented in document EP3267729A1 with three types of network nodes. Namely, the edge nodes, the relay nodes, and the high-end nodes. The edge nodes serve as the source and destination nodes of the network packets. The relay nodes are capable of flood-routing the packet, while the high-end nodes convert the propagation-unspecified packet to a routing-propagation packet. As such, the solution requires performing route discovery and creating and maintaining the routing table, which brings communication overhead and suffers from poor performance with large topology changes in the ad hoc networks. [0007] The proposed deployable wireless ad hoc network system offers a simple, scalable, and cost-effective solution for multi-robot team coordination in challenging environments. Its versatile nature makes it suitable for various applications, including underground exploration, disaster management, vehicular networks, and Internet of Things (loT) distributed sensory networks. The solutions to ad hoc wireless networks need to deal with a priory unknown topology that can be either dynamically discovered, which brings communication overhead, or precise synchronization of the modules can be used, which either requires communication overhead or dedicated hardware adjustments. In our approach, we utilize a simple flood routing approach to propagate the systolic messages through the network. [0D08]The proposed deployable wireless ad hoc network system eliminates complex hardware components and software communication overhead required by the art. Hence it represents an affordable alternative to complex systems while being scalable and sufficiently reliable. [0009] Within the multi-robot team, the proposed Hood routing approach together with the used broadcasting allows effective sharing of the state information about the individual mobile robotic vehicles and possibly their commanding, which improves the overall performance of the robotic team in the execution of the designated mission. SUMMARY OF THE INVENTION [0010] The herein-described deployable wireless ad hoc network system addresses the need for wireless communication in otherwise communication-denied environments. It includes static nodes and dynamic nodes, a routing protocol, and a transmission scheduling policy that accommodates dynamic network topology chan