53 accepted papers
Modeling environmental forces remains a critical challenge in the design and control of robots operating on granular terrain. In pushing locomotion, propulsion is generated by displacing a large number of particles; however, the resulting terrain deformation complicates accurate real-time force pred…
Improving motion speed and efficiency remains a critical challenge in snake robots gait control. This paper introduces the Loop gait, a novel locomotion gait designed to enhance both speed and energy efficiency of snake robots without passive wheels. Compared to Crawler gait and S-pedal gait, which
In this letter, we present an innovative, tightly-coupled LiDAR-Visual-Inertial Odometry and Mapping framework, termed LVIO-Fusion, which achives robust and precise state estimation and map construction in environments characterized by LiDAR-degenerated and texture-less. The LVIO-Fusion is comprised
With the aging of critical infrastructure like bridges and plant facilities, the development of innovative wall-climbing robots using permanent magnets has become increasingly important. Traditional designs of such robots depend on controlling the position of lifters or permanent magnets to control
Soft robotics, including soft grippers and manipulators, are increasingly required to function more adaptively and securely in unknown environments. However, conventional soft pneumatic grippers often grasp and hold objects via the active bending of multiple fingers, making it challenging to grip an
Rescue robots require versatility and the capability to operate in various environments to carry out a diverse set of tasks effectively. The eccentric paddle (ePaddle) mechanism stands out for its high efficiency and adaptability. Generally, it is designed as a quadruped robot with a combined struct…
Enlightened by the creeping gait of natural snakes, snake-like robots swing joints side to side at similar tracks for generating propelling forces. However, it is not always essential to control all joints of a snake-like robot to realize the creeping gait. Therefore, in this paper, a creeping snake…
This paper mathematically conceives a novel walking support device that leverages passive dynamics and coupling effects. In this model, a passive human walker is flexibly connected to an active humanoid, where the coupling effect induces a stable walking gait of the human. To understand the key mech…
This paper presents a method of drawing pipeline routes using a sensing unit with a rotary encoder and IMU (Inertial Measurement Unit), which is towed by a self-propelled in-pipe inspection robot. However, the IMU information generally contains integration errors, making it difficult to draw accurat…
The goal of this paper is to develop an ultrasonic detection device that can be mounted on an underwater snake vehicle (USV) for underwater district heating pipe (DHP) detection in the future. Ultrasonic detection technology (UDT) is the detection means used, and the cavitation defects in polyuretha…
Disturbances widely exist in all control systems. Disturbance observers are commonly employed to estimate the disturbances which are often fully compensated in the control signal. However, one rarely recognized fact is that disturbances may be beneficial to the control performances and thus can be e
Compliance is good. However, it is challenging for one compliant continuum robot to finish both high precision manipulation and environmental-adapted motions. In this paper, a modular continuum robot with the alterable compliance characteristic is proposed. Besides, an actuation module is also propo…
Reinforcement learning commonly suffers from slow convergence speed and requires thousands of episodes, which makes it hard to be applied for physical robotic applications. Little research has been studied for snake robot control using RL because of the additional difficulty of high redundancy of fr…
Undulation is the most common gait generated by legless creatures, which enables their robust and efficient locomotion in various environments. Such advantages inspired the control design of many kinds of locomotion robots. Despite their technical details, most of them realize the undulation gait vi…
Regular maintenance of pipelines is an important task to ensure oil transportation and other operation (sewers, nature gas). Precise localization of pipeline damage can greatly improve the efficiency of maintenance work. Since the texture similarity and illumination change of pipe, traditional local…
The performance of a robot is closely related to its structure. From the initial design of link lengths to structural optimization, it is still the research hotspot in recent years. To make the manipulator lightweight and ensure its working range and flexibility, researchers have proposed many optim…
This letter proposes a real-time optimal robust path following control scheme for planar snake robots without sideslip constraints using model predictive control (MPC). One of the features is that a linear double-integrator model rather than the complex dynamic model of snake robots is used for the
Lampreys’ posterior dual dorsal fins can function as a thrust booster. In addition, the fin-fin interaction of these dorsal fins enables utilization of the energy from the wake, making this species one of the most efficient swimmers. Thus, this dorsal fin configuration can serve as a great source of
The paper reports the performance verification of vertical bend and T-branch travels of an articulated wheeled in-pipe inspection robot. The robot is composed of only a single active compliant middle joint, two passive compliant joints, three drive wheels, and two roll wheels. The passage of the ben…
Reinforcement Learning (RL) usually needs thousands of episodes, leading its applications on physical robots expensive and challenging. Little research has been reported about snake robot control using RL due to additional difficulty of high redundancy of freedom. We propose a coach-based deep learn
Snake robot control usually adopts a centralized framework using high dimensional states, which suffers from exponentially increased computational cost with module number. Although decentralized control schemes have been proposed by using central pattern generators, the dynamical correlation among s
This paper presents a wheeled V-shaped in-pipe robot in which the two outputs of the wheel shaft and roll joint are driven solely by a single actuator input. This underactuation is generated by a simple miter gear mechanism. Generally, to control two movements easily, one of the outputs of the under…
To cope with the requirements on efficiency and labour-saving of the out-pipe surface grinding tasks in the wild, several proposals are revealed and discussed. The one benefiting from the characteristics of planetary gear transmission and friction actuating mechanism are expatiated. To realize full…
Particular tasks performed in narrow and confined spaces require a capability of passing through a limited pathway. Consequently, previous research developed a snake-like robot that generates a 1-D rectilinear gait with an appropriate mechanical design. In contrast, a rigorous mathematical model and
Biological observations on tetrapods locomotion deduce that anti-phase synchronization (APS) between fore and rear parts is beneficial for achieving a high-speed walking. On the other hand, theoretical analysis and experimental studies on quadruped robots suggest that a flexible spine potentially im…
Compared with torque-control techniques, a position-controlled quadruped robot is lower cost, easier to build, and more direct to drive. However, the stiff actuation of position-controlled actuators makes it difficult for the quadruped to achieve dynamically stable locomotion. This paper presents an…
This paper presents a novel Bayesian-based controller for snake robots in cluttered environment. It extends the conventional shape-based compliant control into statistical field providing an explicit mathematical formulation with Bayesian network. A sequential density propagation rule is derived by…
AIRo-5.1 an in-pipe inspection robot comprised of two passive compliant joints and a single active compliant joint that is driven by a series elastic actuator (SEA) is presented in the course of this study. As an aid in pipeline maintenance, AIRo-5.1 controls joint angles and the torque of middle jo…
Creative design of grippers on their configurations, mechatronics control system, and multi-component collaborative algorithms is often utilized to realize complex operations in industrial applications, due to the environmental constraints or specific task requirements. Firstly, this paper introduce…
A floating base system is inevitably to contact the environment while it is moving. This paper explores the contact force estimation and regulation algorithm for a position-controlled floating base system without joint torque information. First, the joint space dynamic model of the system is present…
In this paper, we updated an inspection robot with passive adaptation ability, which is used to detect small size water supply pipeline. By geometric calculation and kinematic verification, static model of the robot is checked for flexible movement in the pipeline. Besides, inertial measurement unit…
To access rough terrain and enhance the mobility in sandy terrain, a configurable paddle-wheel robot was pro-posed. This report addresses the paddle terradynamics, and the experimental verification of the locomotion performance of the robot over dry sandy terrain. To study the interactive forces bet…
This study presents an in-pipe inspection robot module, called AIRo-2.3s. This robot module can control its joint angle and torque and adapt to any directed bent pipe regardless of its orientation. Stretching the drive wheels against the inner wall of pipes is essential for adapting robots to be use…
This study presents a differential elastic joint for use in multi-linked pipeline inspection robots. Active joints to stretch against the pipe wall are essential for adapting robots to use in vertical pipes and slippery inner surfaces where a large traction force is required. Series elastic actuator…
To enhance the motion performance of all-terrain robots, an eccentric paddle mechanism (ePaddle) based on planet gear mechanism was designed. This letter is on the design, control scheme, and implementation of a wheel-paddle integrated quadruped robot based on the ePaddle mechanism. To ensure the re
This paper presents the dynamic modelling and motion planning method for a quadruped robot that uses its legs for nonprehensile manipulation as well as locomotion. Three different working modes named Drive Mode, Inchworm Mode and Scoot Mode are proposed to enable the robot to move forward together w…
This paper presents the dynamic modelling and motion planning method for a quadruped robot that uses its legs for nonprehensile manipulation as well as locomotion. Three different working modes named Drive Mode, Inchworm Mode and Scoot Mode are proposed to enable the robot to move forward together w
This paper explores the control strategy for a multi-limb robot nonprehensilely pushing an object to slide on the floor. The robot's limb distals perform point contacts with the object and the floor. The contact velocity constraint and force constraint are proposed to prevent separation and restrict…
A novel gait planning and control framework was developed for quadruped locomotion of a robot. It modeled the quadruped robot as two bipeds carrying the body from the front and rear ends. We first mapped the relationship between the joint torques of support legs and the torso forces of the bipedal s…
This letter proposes an $N$-link snake robot with parallel elastic actuators (PEA) and a stiffness property that reduces the energy consumption during fast movement. Each PEA couples the actuator output to a spring element, enhancing the periodic gait as demonstrated in previous studies of walking r
In this paper, we present a multi-link articulated wheeled in-pipe robot that can drive the wheel and roll joint by using only a single actuator installed in each link. The proposed mechanism enables the robot to move forward or backward and helically in pipes owing to rotation of the drive wheel an…
This paper presents an anisotropic shadow-based operation assistant method for a multilink-articulated wheeled pipeline-inspection robot by using a single illuminator and camera. By displacing the position of the illuminator relative to that of the head camera, a crescent-shaped shadow appears in th…
The planar rimless wheel (PRW) is a classic and simple passive dynamic mechanism to simulate biped walking, different simplified PRW models have respective descriptions and limited applications. This paper focus on constructing the general PRW model, and analyzing the intrinsic and mathematical rela…
Snake robots have been researched for locomotion in unstructured environments due to its unique and adaptable gaits, however, they have not been used to interact with the environment in a dexterous manner, for example to grasp or push an object. In this paper, the effect of both the configuration of…
This paper presents a multilink-articulated robot with omni and hemispherical wheels (AIRo-II) for inspecting and exploring winding pipes. To quickly adapt to winding pipes, holonomic rolling movement without moving forward and backward is more useful. However, this requires the replacement of drivi…
The safety of working on walls has been improved by several adsorption mechanisms most of which sustain the absorption by pumps or other actuators. This research proposes an alternative method (a spring-suspended suction cup with a buckled plate spring) that can be attached for long durations withou…
This paper designs a guide rail for a wall-climbing robot based on passive suction cups. The designed guide rail can guarantee stable climbing of a wall-climbing robot. Firstly, to design the parameters of the guide rail, properties of the utilized passive suction cup are experimentally studied. The…
Robots capable of both locomotion and interaction with the environment are necessary for robots to move from ideal laboratory situations to real applications. Snake robots have been researched for locomotion in unstructured environments due to its unique and adaptable gaits. However, they have not b…
This paper presents and discusses the trajectory tracking control design with friction compensation for a three wheeled omnidirectional mobile robot. Firstly, a dynamic model without considering the friction forces is derived. Part of the control effort is used to compensate the friction effects, wh…
Snakes and worms are capable of travelling along a straight line on a resistance medium using rectilinear locomotion. To apply this kind of gait in snake-inspired robots, some fundamental properties remain elusive. In this paper, we study the directional migration of a three-segment self-propelled s…
To gain high mobility on challenging terrains, a mobile robot based on eccentric paddle mechanism (ePaddle) with locomotion versatility has been proposed. In this paper, a paddle-aided stair-climbing motion is presented for this ePaddle-based robot. The robot can roll on the stair as a traditional w…
Snakes and worms are capable of travelling through tightly confined spaces on a resistance medium using rectilinear locomotion. To apply this kind of gait into snake-inspired robots, some fundamental properties remain elusive. In this paper, we present a n-segment kinematic model of the snake robot…
Snake robots are highly redundant robots that could potentially be used as robotic arms, allowing them to interact with the environment. However they do not have a fixed base, making them difficult to control accurately. In this paper, a complete modeling approach and an optimization algorithm are p…