Robot Manipulator Control Technology Compensating for Nonlinear Friction Using a Low-Pass Filter Observer

This technology is a robot manipulator and control method that estimates and compensates for nonlinear friction in real-time without linearization. It utilizes only the robot's built-in motor current and encoder-based joint position data, eliminating the need for external force/torque or acceleration sensors by employing an observer equipped with a low-pass filter.

Conventional friction measurement methods often suffer from low cost-efficiency due to the requirement for expensive force/torque sensors, while observer-based methods frequently face issues with reduced estimation accuracy and limited application scope when simplifying nonlinear friction characteristics.

This technology proposes a method that mathematically estimates friction torque within the robot's dynamic equations using an observer with an integrated low-pass filter. It performs calculations while preserving nonlinearity, based on a dynamic model that includes the inertia matrix, Coriolis force, gravity vector, and gear ratio. By compensating for friction without additional sensors, it significantly improves positioning precision, making it ideal for precision assembly and force control tasks.

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Key Features:

• A sensing step that acquires joint information, including the rotation angle of the joint, and motor current.
• A step that estimates and calculates friction torque based on the sensed joint information, motor current, and pre-set estimation data.
• A configuration that estimates friction torque within dynamic equations via an observer with an integrated low-pass filter.
• A control step that compensates for friction by incorporating the estimated friction torque into feedback control.

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for human-product haptic simulation technology.

Variable Stiffness Robot Joint System with Differential Gear for Combined Rotation and Stiffness Control

This technology is a differential gear-based variable stiffness robot joint system that uses two independent drive motor inputs to selectively perform joint rotation and stiffness adjustment based on the combination of the motors' rotational directions.

Conventional variable stiffness joints suffer from low drive efficiency and design redundancies, as one motor is dedicated solely to joint actuation while the other is dedicated solely to stiffness control.

This technology proposes a method where a first rotation module converts the motors' same-direction rotational force into joint rotation, while a second rotation module converts opposite-direction rotational force into linear motion to adjust the preload of an elastic member, thereby varying stiffness. Applicable to collaborative and rehabilitation robots, it maximizes both hardware efficiency and output by utilizing both motors.

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Key Features:

• First and second drive modules, each generating rotational force about a first direction axis
• A first rotation module that converts rotation to rotate the joint when both drive modules rotate in the same direction
• A stiffness provision module that elastically supports the rotational motion of the first rotation module to provide stiffness
• A second rotation module that converts motion into linear motion to adjust preload when the two drive modules rotate in opposite directions

Modular Climbing Maintenance Robot System with Universal Connector-Based Mobility Module Exchange

This technology is a maintenance robot system featuring a modular climbing mechanism that connects the robot's main body to a climbing mobility module via a universal connector, allowing the mobility module to be swapped according to the work environment.

Conventional technology relies on climbing mechanisms fixed to the complex exterior structures of high-rise buildings, leading to cost inefficiencies as it requires developing separate robots or maintaining a large fleet of robots tailored to specific building characteristics.

This technology utilizes a detachable universal connector between the main body and the climbing module, enabling the use of various interchangeable mobility modules such as legged, wheeled, or tracked types, with an auxiliary control unit that automatically recognizes the swapped module. Applicable to exterior cleaning, painting, and facility inspection, it eliminates the need to develop new robots for each building, significantly reducing implementation costs.

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Key Features:

• A work module for performing maintenance tasks such as exterior building cleaning, and the robot main body to which it is attached.
• A universal connector fixed to the connection point on the main body, serving as the interface for connecting to the climbing module.
• A climbing module selected based on the building's exterior structure and designed for interchangeable connection to the universal connector.
• A connector structure that integrates the gear drive shaft for power transmission with pneumatic, power, and control signal connections.

Multi-rotor unmanned aerial vehicle system for mechanical tasks using detachable tool coupling

This technology provides a connection structure that allows for the detachable coupling of various tools to a general-purpose unmanned aerial vehicle (UAV), creating a multi-rotor UAV system where multiple drones are integrated and controlled to perform specific mechanical tasks.

Previously, there were inefficiencies in having to manufacture dedicated drones for each type of tool, as well as complexities in the control algorithms and system design required for each robot to perform high-difficulty tasks.

This technology introduces a standardized detachable connection and identification structure between the tool and the drone, and proposes a method for controlling multiple UAVs based on an integrated task process received from a control unit. This ensures versatility, allowing a single drone platform to perform a wide range of mechanical tasks. It can be utilized for facility maintenance, construction work, and disaster prevention, significantly increasing the economic efficiency of drone operations by enabling various missions to be performed simply by swapping tools.

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Key Features:

• Multiple unmanned aerial vehicles equipped with a support frame, multiple rotors for propulsion, and a tool connection interface
• A control module coupled to the support frame that manages rotor operation and handles external communication with the control unit
• A work tool featuring multiple drone connection interfaces that allow for the detachable coupling of the UAV's tool connection interface
• A control unit equipped with a storage module for task control processes and a communication module for transmitting control signals

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This invention was developed with support from the Ministry of Education, Science and Technology’s Convergence Knowledge-Based Creative Mechanical and Aerospace Talent Training Program and the research project on mechanical manipulation control techniques for quadrotor robots.

Collaborative Control Technique for Multiple Mobile Manipulators Based on Non-Holonomic Passive Decomposition

This technology is a collaborative control and obstacle avoidance method that uses non-holonomic passive decomposition to independently control the formation maintenance of mobile manipulators, object transport, and obstacle avoidance tasks within separated vector spaces.

When multiple mobile manipulators collaborate, tasks such as maintaining manipulator formation, moving objects, and avoiding obstacles often interfere with one another, making precise control difficult. Furthermore, single-path control methods struggle to efficiently handle both obstacle avoidance and task execution simultaneously.

This technology proposes a method that decomposes the state of mobile manipulators into four independent vector spaces: formation changes, object position changes, platform translation and rotation, and movement interference factors, calculating control inputs for each independently. When obstacles are encountered, the system utilizes redundant degrees of freedom to adjust internal configurations and employs potential functions for avoidance, allowing for safe collaboration while maintaining the intended path. Applicable to multi-robot logistics, collaborative transport of large objects, and factory automation, this approach maximizes control efficiency for collaborative robots by achieving task execution and obstacle avoidance simultaneously.

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Key Features:

• Control inputs calculated and applied independently for the vector space that modifies the formation of the mobile manipulators' mechanical arms.
• Control inputs for the vector space that modifies the position of the mobile manipulators' mechanical arms or the objects being transported.
• Control inputs for the vector space that rotates and translates the mobile manipulator platforms while maintaining formation.
• Control inputs for the vector space that simultaneously interferes with formation maintenance and movement.

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This invention was developed with support from the Ministry of Science, ICT and Future Planning’s research on real-time control and haptic rendering for haptic interaction between multiple remote users, and the Ministry of Education, Science and Technology’s program for fostering creative mechanical and aerospace talent based on convergence knowledge.

Aerial Manipulator Technology for Manipulating Unknown Structures via End-Effector Velocity Estimation

This technology is an operating system and method for mechanical structures that controls the thrust and moment of a multirotor by estimating the real-time velocity of a robotic arm's end-effector, inputting it into a directional filter to dynamically model the movement direction and mechanical constraints of unknown structures like drawers, and optimizing ideal force settings and end-effector trajectories.

When aerial manipulators operate constrained mechanical structures such as drawers or doors, effective interaction and precise force control have been difficult due to a lack of prior information regarding the structure's movement direction, mass, damping, and other dynamic characteristics.

This technology proposes a method that detects structural movement using an end-effector velocity estimator, estimates the constrained movement direction through a directional filter, and calculates the appropriate force required for structural movement via an ideal force setting unit. This allows for the control of the multirotor's position and orientation to interact harmoniously with mechanical structures. It can be utilized for facility inspections, opening doors in disaster zones, and remote operations, significantly enhancing the operational autonomy of aerial robots by enabling interaction without prior information about the target structure.

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Key Features:

• A position acquisition unit that obtains real-time location information for an aerial manipulator consisting of a multirotor equipped with a robotic arm.
• An end-effector velocity estimation unit that estimates the velocity of the end-effector attached to the tip of the robotic arm based on the location information.
• A directional filter that estimates the movement direction of the mechanical structure using the velocity of the end-effector.
• An ideal force setting unit that moves the mechanical structure at an ideal speed, and a controller that calculates the thrust and moment of the multirotor.

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This invention was developed with support from the Convergence Knowledge-Based Creative Mechanical and Aerospace Engineering Program of the Ministry of Education, Science and Technology.

Passive Exoskeleton Device for Upper Limb Strength Assistance Using Elastic Members and Directional Clutches

This technology is a mechanical exoskeleton system that assists a user's upper limb strength using elastic members and a clutch mechanism without an external energy source. A rotational elastic unit connected to a sliding hole releases stored elastic force during the movement of the rotational part, while a gear- and protrusion-based clutch part selectively allows or restricts movement in specific directions during bidirectional rotation to control the assistive force.

Conventional upper limb exoskeleton robots necessarily include electric actuators, which result in heavy device weight, high costs, and technical limitations in efficient operation due to constraints on energy source (battery) life and usage.

This technology consists of a body part, a rotational part, and a connecting part (including a rotational elastic unit) to assist muscle strength solely through elastic force without an energy source. The clutch part includes first and second clutch units, protrusions, and protrusion elastic members; it controls the rotational direction by changing the engagement state of the gears via switch operation, thereby performing assistive movements based on the load of an object. It can be applied to industrial muscle assistance, rehabilitation, and logistics, reducing weight, cost, and operational constraints by eliminating the need for batteries.

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Key Features:

• An upper limb exoskeleton assist device, wherein the second clutch unit further comprises a second protrusion elastic member that elastically supports the second protrusion.
• A clutch part comprising a first clutch unit that allows rotation of the rotational part in one of a first direction or a second direction, and a second clutch unit that allows rotation in the other direction.
• A rotational part connected to the body part to be rotatable in a first direction or a second direction opposite to the first direction.
• A connecting part that connects the body part and the rotational part, and applies elastic force to the rotational part when the rotational part rotates in the first direction.

Hand Rehabilitation Exoskeleton with Independent Finger Joint Actuation via Rotary Pushers and Wire Tension

This technology provides an exoskeleton structure that combines rotary pushers with sliding links and multiple wire tension mechanisms to achieve independent flexion/extension and abduction/adduction for each finger joint (MCP, PIP, DIP, CM, IP).

Conventional exoskeleton robots are limited to simple grasping motions due to restricted degrees of freedom and struggle with independent joint control, making it difficult to implement complex and precise hand movements.

This technology utilizes a rotary pusher motor to position a cam-shaped rotary pusher that applies pressure to the proximal phalanx attachment, while independently driving wires for each finger segment to enable flexion, extension, abduction, and adduction for every joint. Applicable to hand rehabilitation, wearable robotics, and physical therapy, it enhances rehabilitation efficacy by enabling precise hand movements through independent joint control.

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Key Features:

• A third wire that passes through the upper side of the thumb distal phalanx attachment, the upper side of the thumb proximal phalanx attachment, the upper side of the thumb CM attachment, and the upper side of the palm attachment to generate thumb extension.
• A fourth wire that passes through the lower side of the thumb distal phalanx attachment, the lower side of the thumb proximal phalanx attachment, and the lower side of the thumb CM attachment to generate thumb flexion.
• An exoskeleton mechanism including a sixth wire fixed to the lower side of the thumb CM attachment and passing through the lower side of the palm attachment toward the ring finger to generate thumb abduction.
• A fifth wire fixed to the upper side of the thumb CM attachment and passing through the upper side of the palm attachment to generate thumb adduction.

Muscular Strength Assistive Device

This technology is a fiber-based actuator mechanism that physically assists with joint flexion and extension. It features heat-shrinkable/expandable polymer fiber warps integrated into a body worn on the upper or lower limb joints, which are individually controlled via heating wires.

Conventional metal exoskeleton structures are heavy and complex, which reduces user comfort, requires significant space for fitting, and restricts natural movement.

This technology integrates heat-shrinkable and expandable polymer fibers (homochiral/heterochiral warps) into a body to form a fiber-based muscular strength assist unit. Based on data from electromyography (EMG) sensors, it selectively controls the contraction and expansion of inner and outer warps according to the direction of joint flexion to actively assist movement. It can be applied to rehabilitation training, gait assistance, and medical/welfare services, enhancing ease of movement and improving the fit for joint support.

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Key Features:

• A body section designed to wrap around upper or lower limb joints
• A muscular strength assist unit mounted on the body section that operates by detecting joint movement
• The muscular strength assist unit features heat-shrinkable and expandable warps arranged alternately at intervals
• A configuration that individually controls the contraction and expansion of inner and outer warps during joint flexion and extension

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for the development of renewable energy and intelligent robot convergence technology.

Active Upper Limb Exercise Assist Device

This technology features a structural combination of a cuff that accommodates the user's arm for upper limb rehabilitation and a multi-joint robot module that controls it. It physically guides wrist rotation through an arc-shaped guide rail and sliding bracket within the cuff. Based on the movement of the handle and sensor data from within the cuff, the motion controller calculates and regulates the robot's 6-degree-of-freedom assistive force.

Conventional technologies are limited to specific tasks such as assisting with meals and fail to account for individual physical characteristics. Furthermore, they lack the ability to detect independent wrist rotation along the longitudinal axis of the arm or provide force assistance, resulting in lower precision for rehabilitation training.

This technology incorporates a handle and motion sensor to detect wrist rotation, along with a sliding mechanism using an arc-shaped guide rail and rollers within the cuff. The motion controller identifies the user's intent to guide 6-degree-of-freedom movement via the multi-joint robot module and provides assistive force for wrist rotation through an electric motor. Applicable to rehabilitation training, gait assistance, and medical/welfare services, it improves the user's upper limb exercise experience by accounting for physical characteristics and arm positioning while providing comfortable force assistance.

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Key Features:

• An active upper limb exercise assist device including a motion sensor positioned between a support piece and a handle, which detects the intent for wrist rotation based on the movement of the handle.
• A multi-joint robot module that selectively guides 6-degree-of-freedom movement in a Cartesian coordinate space and provides assistive force for the upper limb positioned in the cuff.
• A handle provided on the upper surface of the support piece, designed for the user to grip to facilitate wrist rotation.
• A pair of bracket members that slide along the outer ends of guide rail members positioned at the rear.

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for research on physical/cognitive interaction-based neuro-robot technology.

Gravity Compensation Device for Both Rotary and Linear Joints

This technology relates to a gravity compensation device for rotary and linear joints, utilizing a cam and a torsion spring to counteract the gravitational torque acting on the joints.

Existing gravity compensation structures often cause unnecessary displacement and torque during linear motion, which increases energy consumption and reduces the efficiency of manipulator robots.

By combining a cam follower, a torsion spring, and a belt-pulley transmission element, this technology compensates for gravity in both rotary and linear joints, thereby improving energy efficiency. It is applicable to rehabilitation devices, flight simulation equipment, and more.

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Key Features:

• A joint member installed to allow both rotation and linear movement relative to the housing
• A cam profile that rotates in conjunction with the joint member, and a cam follower that moves vertically along the cam profile
• A spring pressure mechanism installed within the housing to move with the cam follower and transmit elastic force
• A torsion spring that operates in conjunction with the linear movement of the joint member and is compressed by the spring pressure mechanism to provide elastic force in the direction opposite to the rotation

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This invention was developed with support from the Ministry of Science and ICT for the development of an integrated gravity compensator for the miniaturization of wearable robots.

Unidirectional Compensator for Mechanical Creep Compensation

This technology relates to a unidirectional creep compensator and a twisted string actuator equipped with the same, designed to mechanically compensate for creep occurring in flexible material reduction elements.

Actuators using fiber materials, such as twisted string actuators, have historically suffered from performance degradation and reduced repeatability due to the accumulation of creep during prolonged use.

By applying continuous contractile force to the drive line using only an elastic structure and a one-way bearing, this technology compensates for creep, maintaining control performance and repeatability without the need for additional sensors or complex control systems.

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Key Features:

• A twisted string drive unit that generates tension in the drive string as a pair of twisted string units move in opposite directions.
• A joint member and output shaft that receive power from the twisted string drive unit to enable bidirectional motion control.
• An auxiliary drive unit connected to the output shaft of the joint member to directly control the bidirectional motion of the output shaft.
• An elastic structure that stores contractile force and applies it to the drive string when creep occurs to compensate for the displacement.

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of a compact, lightweight, high-performance, and highly durable safe drive module based on string twisting, utilizing string surface reinforcement, variable radius pulleys, and hybrid drive control, as well as support from the Ministry of Science and ICT for the second phase (third stage) of bionic wrist design technology development.

LiDAR-based Mobile Object Localization Using Split Scan Synthesis and Point Cloud Matching

This technology estimates the position of a mobile object by receiving scan data at intervals shorter than the time required for a single LiDAR rotation, synthesizing it with previous scan data to acquire a point cloud, and then identifying the closest point cloud within a point map.

Conventional LiDAR-based localization requires a full sensor rotation to process data, resulting in long position update intervals and often necessitating additional sensors to improve precision.

This technology proposes a pipeline-based approach that synthesizes and matches scan data received at short intervals, shortening the localization cycle without the need for extra sensors. It can be applied to autonomous vehicles and indoor logistics robots, providing an economical solution that enhances both position update speed and precision using only existing sensors.

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Key Features:

• Receiving scan data at a second duration that is shorter than the first duration required for a single LiDAR rotation
• Synthesizing the received scan data with scan data from a previous time point stored in units of the second duration
• Acquiring a first point cloud of the mobile object's surroundings based on the synthesized scan data
• Estimating the position based on the point cloud in the point map that is closest to the first point cloud

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This invention was developed with the support of the Ministry of Science and ICT's research on fault-tolerant real-time virtualization technology for high-reliability autonomous driving systems.

Underwater Robot for Submerged Tunnel Inspection Using a Guide-Wire-Connected Mother-Ship and Survey-Ship System

This technology features an underwater robot system where a first and second mother-ship are attached to the surface of a submerged tunnel, connected by a guide wire. A survey-ship travels back and forth between them to acquire sensing data, with winch winding control and directional adjustment units used to sequentially shift the survey area.

Existing methods faced challenges in maintaining the precise distance required for inspection due to the risk of collision between the robot and the tunnel, as well as a lack of technical solutions for efficient, continuous monitoring while moving along the tunnel surface.

This technology proposes a method where two mother-ships are fixed to the tunnel surface, allowing a survey-ship to travel along a guide wire to inspect the surface using optical and acoustic sensors. The mother-ships use winches and directional adjustment units to perform longitudinal movement and rotation. This enables automated, precise inspection of submerged tunnels and undersea structures while maintaining a constant distance to eliminate collision risks.

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Key Features:

• A first mother-ship attached to the submerged tunnel surface, including a first winch and a first directional adjustment unit connected to one end of the guide wire.
• A second mother-ship attached longitudinally, including a second winch and a second directional adjustment unit connected to the other end of the guide wire.
• A survey-ship that inspects the surface of the submerged tunnel while moving along the guide wire from the first mother-ship toward the second mother-ship.
• A configuration that changes the survey area by moving the mother-ships through winch winding control and directional adjustment units.

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This invention was developed with support from the Smart Underwater Tunnel System Research Center of the Ministry of Science and ICT.

Autonomous Mobile Robot System Combining Block-Based Path Planning and Real-Time Information Sharing

This technology is an autonomous mobile robot system and control method that manages autonomous vehicles based on block-defined travel paths. It prevents deadlocks by sharing location and speed data between multiple vehicles in real time, allowing for path rerouting or speed adjustments at potential collision points.

Conventional magnetic tape guidance systems incur high maintenance costs when environmental changes occur, and their centralized control systems often fail to account for the real-time status of each vehicle, limiting operational efficiency and collision prevention.

This technology structures travel paths by defining blocks using outlines, ways, surfaces, and task markers. The system controller collects operational data from each vehicle and calculates virtual travel times to determine optimal rerouting or speed adjustments. Applicable to smart factories and logistics centers, it enables flexible path changes and collision-free operations without the need for floor infrastructure modifications.

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Key Features:

• Vehicle drive unit equipped with vehicle sensors and a drive motor for the vehicle body
• Vehicle control unit connected to the vehicle sensors and drive unit to manage motor operation
• Configuration for setting and inputting travel paths from origin to destination in block-based units
• System controller that shares location and speed data among multiple vehicles to manage rerouting or speed control at potential collision points

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of logistics robot systems applicable to wide-area hospital environments.