# US 12,759,683 B2 · Underwater snake robot with passive joints > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,683 B2 - Document ID: US12759683B2 - Status: Granted - Kind: B2 - Application number: 18/245,826 - Filed: 2021-09-17 - Published: 2024-01-25 - Granted: 2026-10-13 - Earliest claimed: 2020-09-18 - Assignees: Eelume AS - Applicants: Eelume AS - Inventors: Pål Liljeback - Web page: https://patentgrep.com/patent/US12759683B2 ## CPC - B63G 8/001: {Underwater vessels adapted for special purposes, e.g. unmanned underwater vessels; Equipment specially adapted therefor, e.g. docking stations (self-propelled or direction controlled diving chambers with mechanical link to a base B63C11/42)} - B63G 8/08: Propulsion ({schnorkels B63G8/36;} nuclear propulsion B63H21/18; submerged exhausting apparatus F01N13/12) - B63G 2008/004: {autonomously operating} - B63G 2008/005: {remotely controlled} - B63G: OFFENSIVE OR DEFENSIVE ARRANGEMENTS ON VESSELS; MINE-LAYING; MINE-SWEEPING; SUBMARINES; AIRCRAFT CARRIERS (means of attack or defence in general, e.g. turrets F41H) ## Abstract An underwater snake robot 200 for performing subsea operations, the robot 200 comprising: a series of links 202, 204 that are connected to one another by one or more passive joint modules 201 for allowing a flexural motion of the robot 200; and multiple thrust devices 203 for applying thrust to the robot 200 for propulsion, for generating the flexural motion of the robot and for controlling the orientation and location of the links 202, 204. ## Claims ### Claim 1 An underwater robot for performing subsea operations, the robot comprising: a series of links that are connected to one another by one or more passive joint modules for allowing a flexural motion of the robot; and one or more thrust devices for applying thrust to the robot for propulsion, for generating the flexural motion of the robot and for controlling the orientation and location of the links; wherein the cross-section of the robot, links of the robot and/or thrust device(s) of the robot fit within a diameter of less than 1 metre. ### Claim 2 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules each comprise a flexural coupling with at least two degrees of freedom between adjacent links. ### Claim 3 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules each comprise articulated mechanical joints. ### Claim 4 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules are each couplings between adjacent links without any fixed pivot point. ### Claim 5 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules each comprise a cable connection. ### Claim 6 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules each comprise a connector interface at each end which connects to adjacent links of the robot and allows for individual links and/or joint modules of the robot to be replaced when necessary. ### Claim 7 (depends on 6) An underwater robot as claimed in claim 6, wherein the links and passive joint modules are modular. ### Claim 8 (depends on 1) An underwater robot as claimed in claim 1, wherein the robot comprises at least one battery module. ### Claim 9 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules comprise a signal bus for enabling power transfer and/or communication between links. ### Claim 10 (depends on 1) An underwater robot as claimed in claim 1, wherein thrust devices are located at least at each end of the robot. ### Claim 11 (depends on 10) An underwater robot as claimed in claim 10, wherein further thrust devices are located at positions along the length of the robot between the ends of the robot. ### Claim 12 (depends on 1) An underwater robot as claimed in claim 1, wherein the diameter of the robot is substantially constant across the passive joint modules. ### Claim 13 (depends on 12) An underwater robot as claimed in claim 12, wherein the robot comprises one or more shrouds that ensure the diameter of the robot is substantially constant across the passive joint modules. ### Claim 14 (depends on 13) An underwater robot as claimed in claim 13, wherein at least one of: each shroud is a flexible tube structure with the same diameter as the links of the robot; or wherein each shroud is flooded with water when the robot is in use. ### Claim 15 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules comprise buoyancy elements. ### Claim 16 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules and/or links comprise instrumentation for measuring the angle of flexion of the joint module. ### Claim 17 (depends on 1) A method for control of an underwater robot as claimed in claim 1, the method comprising: controlling the thrust device(s) in order to move the robot into a required orientation and location; wherein the one or more thrust devices are used to generate thrust for propulsion and a flexural motion in the passive joint modules in order to adjust the shape and configuration of the robot. ### Claim 18 (depends on 17) A method for control of an underwater robot as claimed claim 17, wherein the thrust for propulsion and the flexural motion in the passive joint modules in order to adjust the shape and configuration of the robot comes entirely from the thrust device(s). ### Claim 19 (depends on 1) A computer programme product comprising instructions that when executed on a data processing device will configure the data processing device to control an underwater robot claimed in claim 1 by means of a method comprising: controlling the thrust device(s) in order to move the robot into a required orientation and location; wherein the one or more thrust devices are used to generate thrust for propulsion and a flexural motion in the passive joint modules in order to adjust the shape and configuration of the robot. ### Claim 20 (depends on 1) An underwater robot as claimed in claim 1, wherein the passive joint modules only respond to external forces to change their shape and/or angle of flexion.