Rui Song

• Shandong University

The quadruped mobile manipulator (QMM) combines the environmental adaptability of a quadruped robot and the operation capabilities of a robotic arm. The design of the hydraulic QMM with an emphasis on large operational workspace considerations is reported, covering both mechanical design and motion planning aspects. A joint optimization method for...

This study presents a dual-channel disturbance rejection controller for achieving high-precision position control of flexible-joint robots (FJRs) with prescribed performance constraint. The dynamics of the FJR are decomposed into a quasi-steady-state (QSS) model and a boundary-layer model via singular perturbation theory. To effectively address unk...

LiDAR‐based SLAM is recognized as one effective method to offer localization guidance in rough environments. However, off‐the‐shelf LiDAR‐based SLAM methods suffer from significant pose estimation drifts, particularly components relevant to the vertical direction, when passing to uneven terrains. This deficiency typically leads to a conspicuously d...

LiDAR-based SLAM is recognized as one effective method to offer localization guidance in rough environments. However, off-the-shelf LiDAR-based SLAM methods suffer from significant pose estimation drifts, particularly components relevant to the vertical direction, when passing to uneven terrains. This deficiency typically leads to a conspicuously d...

Traditional assembly tasks often require robots to transfer the acquired skills to new tasks. However, previous transfer reinforcement learning methods typically ignore the inherent relationship between the source and the target domain tasks. This requires a substantial amount of interaction data to compensate for this deficiency, and generally res...

Maintaining up-to-date environmental models from initial deployment through long-term autonomy in service is critical for applications like navigation and task planning. To address the challenges of persistent monitoring in unknown environments, we introduce a Two-Stage monitoring strategy, termed the Semantic-level autonomous Exploration and Long-...

This article investigates the torque tracking problem of series elastic actuators (SEAs) that are affected by nonlinear uncertainty and actuator saturation. An unknown system dynamics estimator (USDE), which has only one parameter to be turned, is designed to provide an estimation of the nonlinear uncertainty. Then, based on the estimation, a compo...

This article presents a compact and contactless stage capable of levitating/rotating the wafer via hybrid excitation of standing waves (SWs) and traveling waves (TWs). The stage incorporates two concentrically- arranged irradiators, where the inner one sends out powerful SW to accomplish the levitation while the outer one generates the TW whose int...

Transfer learning and ensemble learning are currently emerging trends in robotics, playing a vital role in the generalization of robot skills for manipulation tasks. In the face of new tasks, previous methods either learn from scratch or require substantial data and experience specific to the target domain, significantly hindering the generalizatio...

The proficiency of robots in cloth manipulation is crucial for their potential widespread deployment in household service contexts, with the task of unfolding cloth being particularly indispensable. Unlike rigid objects, cloth has a high-dimensional state space, which poses significant challenges for robotic operations. This paper presents a roboti...

The continuum manipulators are the most common wrist joint design in surgical robots. However, there is currently no complete and accurate evaluation system to evaluate the performance of the continuum manipulator. In this paper, a static model-based assessment method is proposed to evaluate the dexterity of continuum manipulator. Compared to conve...

The notched continuum robot (NCR), characterized by its compact size and excellent mechanical properties, is extensively used in the design of minimally invasive surgical robots. However, integrating sensors into the NCR in a limited surgical environment is challenging. Using drive state for force estimation is a promising method that relies on the...

Background Nowadays, robots have been widely used in handling rigid objects, but research on deformable objects like fabrics is still in its early stages. This is because fabrics possess infinite degrees of freedom and their state modeling is highly complex, making robot manipulation of fabrics challenging due to the occurrence of wrinkles and defo...

It is challenging for the mobile robot to achieve autonomous and mapless navigation in the unknown environment with uneven terrain. In this study, we present a layered and systematic pipeline. At the local level, we maintain a tree structure that is dynamically extended with the navigation. This structure unifies the planning with the terrain ident...

Conventional model-based control for continuum robots is often based on the assumption of Piecewise Constant Curvature (PCC). However, the real motion of the continuum robot is greatly different from the PCC assumption which makes convergence of the control algorithm difficult to meet the requirements of stability and accuracy. In this paper, a rea...

In computer-assisted orthopedic surgery (CAOS), the overlay of pre-operative information onto the surgical scene is achieved through the registration of pre-operative 3D models with the intra-operative surface. The accuracy and robustness of this registration are crucial for effective interventional guidance. To enhance these qualities in CAOS, we...

The compliance of series elastic actuators (SEAs) is significant for ensuring safe human–machine interaction. However, in practical applications, the SEA is inevitably encountered with unknown disturbances, such as parameter uncertainties, unmodeled dynamics, and environmental interferences. In this paper, a robust dynamic surface control scheme is...

Background Endoscopic submucosal dissection (ESD) is an effective treatment for early‐stage gastrointestinal cancers. However, traditional surgical instruments lack accuracy and force‐sensing. Methods A new type of continuum robot for ESD is designed. An accurate static model of the proposed continuum robot is established, considering cases where...

At present, most clothing sewing relies on manual labor, and robot sewing has become a trend. However, different clothing styles have various sewing requirements. This poses a challenge for robot sewing, and the key to solving this challenge lies in the planning of robot operation trajectories. Although the shapes of sewing components are diverse,...

An untethered ultrasonic robot (U2sonobot) operating in resonant vibration is developed by integrating dual transducers, an onboard circuit, and a battery. Here, the longitudinal and bending vibrations lead to the out-of-phase swing motion and the alternating acceleration, respectively; these imitate the rotatory galloping gait in terms of the driv...

Traversability analysis is of vital importance for autonomous vehicle navigation in outdoor environments. This paper focuses on the navigation algorithms in outdoor environments with water hazards, where the water areas can neither simply be neglected nor be deemed as non-traversable for safe and efficient navigation. To this end, we present a tigh...

A self-moving piezoelectric actuator (SMPA) with high carrying/positioning capability is presented in this article. Its ×π-shaped mechanical part comprises four piezo-legs, each of which combines the bending vibrations in the first three orders into the motion in the quasisawtooth waveform at the driving foot. Besides, a homemade onboard circuit is...

This article presents a miniature pole-climbing piezoelectric robot (MPCPR) with fast and load-towable movement. Basically, it incorporates a pair of alumina transducers, where the third bending (B3) and second bending (B2) vibrations are excited independently in the time domain to enable the MPCPR to climb up and down the external tubes; this inte...

Hindsight experience replay (HER) has greatly increased the possibility of using deep reinforcement learning (DRL) for robotic manipulation with sparse rewards. However, there are still concerns about low learning efficiency and poor performance due to its insufficient exploration ability and bias against the initial goal introduced by HER. In this...

A robot screwing skill learning framework based on teaching–learning is proposed to improve the generalization ability of robots for different scenarios and objects, combined with the experience of a human operation. This framework includes task-based teaching, learning, and summarization. We teach a robot to twist and gather the operation’s trajec...

Deformable object manipulation has been considered a challenging task for robots for its complex dynamics and the infinite dimensional configuration space. Fabric unfolding manipulation takes on critical significance in the textile industry and household services. Accordingly, enabling robots to possess the above-mentioned skill has been confirmed...

In the actual sewing process, the clothing styles are diverse, and the sewing parts are complex. There are different seam type requirements for different parts. Sewing components such as pockets, chest linings, front and rear sheets are made up of straight lines and curved edges of different shapes. The operation trajectory of the robot is difficul...

This paper presents the design and control of a high-speed running bipedal robot, BRAVER. The robot, which weighs 8.6 kg and is 0.36 m tall, has six active degrees, all of which are driven by custom back-driveable modular actuators, which enable high-bandwidth force control and proprioceptive torque feedback. We present the details of the hardware...

Based on the grey wolf optimizer (GWO) and differential evolution (DE), a hybridization algorithm (H-GWO) is proposed to avoid the local optimum, improve the diversity of the population, and compromise the exploration and exploitation appropriately. The mutation and crossover principles of the DE algorithm are introduced into the GWO algorithm, and...

Ultrasonic motors (USMs) have been extensively investigated for a few decades, but it is still required to improve their thrust force (or torque) density and/or power density for practical usage. According to conventional actuating methods, the dimensions of the transducers are difficult to greatly change after modal degeneration; this restricts th...

Background: As an important part of robot operation, peg-in-hole assembly has problems such as a low degree of automation, a large amount of tasks and low efficiency. It is still a huge challenge for robots to automatically complete assembly tasks because the traditional assembly control policy requires complex analysis of the contact model and it...

Skill generalization across different tasks is currently a challenging task for robots. As for recent works based on robot learning, substantial environmental interaction costs or abundant expert data are usually needed, thus causing great harm to the robot or the operating object. In this paper, Feature-Selected Adaptation Transfer (FSAT) is propo...

Given the problem of exploration and utilization, the high interaction cost of deep reinforcement learning is sometimes unacceptable. Moreover, the model trained by deep reinforcement learning cannot adapt to the complex and changeable assembly environment quickly owing to the weak generalization ability. Thus, the knowledge transfer framework is e...

This article proposes a robust command-filtered control method with prescribed performance for flexible-joint robots (FJRs) wherein matched and mismatched disturbances are compensated by designing generalized proportional integral disturbance observers (GPIOs). The contributions are threefold. Firstly, a prescribed performance function (PPF), compa...

Hydraulic legged mobile manipulators are favored because they provide high power density and a strong explosive force. Hydraulic mobile manipulators require contact force control to handle increasingly mobile interaction tasks. However, the highly nonlinear dynamics and model inaccuracy of multiple hydraulic joint systems increase the difficulty of...

Traditional rigid-body in-pipe robots usually have complex and heavy structures with limited flexibility and adaptability. Although soft in-pipe robots have great improvements in flexibility, they still have manufacturing difficulties due to their reliance on high-performance soft materials. Tensegrity structure is a kind of self-stressed spatial s...

Most current in-pipe robots are usually designed for pipes of a specific size. In this paper, we propose a novel inchworm-like in-pipe robot based on the concept of tensegrity for moving in pipes with varying diameters. Firstly, a tensegrity-based robotic module capable of two kinds of shape change is designed. One kind is extension in the axial di...

The regeneration process of severed nerves is extremely slow, and the distance and direction of growth are affected by many factors, making it difficult for doctors to determine the time of suture surgery. Existing treatments, which require doctors to manually pull on an external cord to pull the nerve, are highly uncertain. In this paper, we propo...

This paper proposes a person-following method based on monocular vision, which allows quadruped robots to track a target person in both indoor and outdoor environments with different illumination conditions. Our method is composed of a person detector, a Kalman filter (KF) tracker, and a re-identification module. To be more specific, the person det...

The continuum robot is a new type of bionic robot which is widely used in the medical field. However, the current structure of the continuum robot limits its application in the field of minimally invasive surgery. In this paper, a bio-inspired compound continuum robot (CCR) combining the concentric tube continuum robot (CTR) and the notched continu...

Robot automatic assembly of weak stiffness parts is difficult due to potential deformation during assembly. The robot manipulation cannot adapt to the dynamic contact changes during the assembly process. A robot assembly skill learning system is designed by combining the compliance control and deep reinforcement, which could acquire a better robot...

Background: The master manipulator with position and posture decoupling and force feedback can improve the immersion of the operation, and the gravity balance can reduce the fatigue of surgeons. Methods: A seven degree of freedom master manipulator is developed. The parallelogram structure and the angle conversion method contribute to the realiz...

This study processes the adaptive robust control problem in a task space for a mobile manipulator with uncertain dynamics and external disturbances based on radial basis function neural networks(RBFNN) and a nonlinear state observer. Owing to the high nonlinearity, strong coupling, and unknown uncertainty characteristics of the mobile manipulators,...

A self-moving ultrasonic actuator (SUA) that operated by the longitudinal traveling wave and possessed high carrying/towing capability is developed in this article. The SUA is constructed by serially clamping two longitudinal transducers onto a rectangular-rod-shaped vibrating body, and its driving feet produce elliptical motions to achieve self-mo...

Snap-fit recognition is an essential capability for industrial robots in manufacturing. The goal is to protect fragile parts by quickly detecting snap-fit signals in the assembly. In this letter, we propose a fast recognition method of snap-fit for industrial robots. A snap-fit dataset generation strategy of automatically acquiring labels is presen...

This paper presents an online LiDAR-only person-following (LoPF) framework, which can be applied in both indoor and outdoor environments with only sparse LiDAR point cloud data as input. The framework consists of two cascade backbone procedures. The former is pedestrian detection, which is developed for classifying a set of human clusters from nois...

This paper presents the development of a novel tensegrity-based robot, TICBot, which is capable of crawling in tubular environments. Based on the concept of tensegrity, a deformable robotic module consisted of discrete rigid struts and a continuous net of elastic springs is proposed. Then the in-pipe crawling robot is designed by serially cascading...

Some quadruped robots developed recently show better dynamic performance and environmental adaptability than ever, and have been preliminarily applied in the field of emergency disposal, military reconnaissance and infrastructure construction. The development route, mechanisms design, control methods and mobile manipulating approaches of the quadru...

The robot’s weak ability to manipulate deformable objects makes robots rarely used in the garment manufacturing industry. Designing a robot skill acquisition frame that can learn to manipulate fabrics helps to improve the intelligence of the garment manufacturing industry. This paper proposes a process learning framework for robot fabric stacking b...

The manipulator system of the robot for natural orifice transluminal endoscopic surgery (NOTES) consists of two parts: The tendon sheath system and the continuum manipulator. The continuum manipulator is connected with the driving element by the tendon sheath system. However, the continuum manipulator is so small that a tiny error in the position o...

To apply ultrasonic motors (USMs) to the chemical industry, in this study, alumina is employed as vibrating bodies of transducers as it offers not only high chemical resistance but also a possibility to generate high output torques and power of motors due to the high Young’s modulus. First, a Langevin-type transducer was constructed by clamping sev...

In this article, a new two-DOF linear ultrasonic motor operating in three vibration modes is developed and its capability to exhibit high thrust force density and high power density is tested. Here, the driving force is produced by synchronously exciting the torsional (T) and centrosymmetric-bending (B <sub xmlns:mml="http://www.w3.org/1998/Math/Ma...

Background NOTES is aided by the instrument channel of an endoscope. Limited by the diameter of the endoscope, the construction of the operation triangle is affected. This paper presents a deployable arm that can increase the distance between the arms. Methods The manipulation arm is composed of a continuum arm and a deployable arm. The deployable...

Lifelong learning is still a great challenge for cognitive robots since the continuous streaming data they encounter is usually enormous and no-stationary. Traditional cognitive methods suffer from large storage and computation consumption in this situation. Therefore, we propose a self-organizing and reflecting cognitive network (SORCN) to realize...

An environment cannot be effectively described with a single perception form in skill learning for robotic assembly. The visual perception may provide the object’s apparent characteristics and the softness or stiffness of the object could be detected using the contact force/torque information during the assembly process. In the process of inserting...

In the present study, a bionic flapping mechanism of a spatial six-bar configuration was designed to transform a single rotation of a motor into a three degrees of freedom “flapping–twist–swing” cooperative motion of a flapping wing. The kinematics model of the flapping mechanism movement was constructed. The flapping trajectory of the wing based o...

An investigation into the aerodynamic characteristics has been presented for a bio-inspired flapping wing aircraft. Firstly, a mechanism has been developed to transform the usual rotation powered by a motor to a combined flapping and pitching motion of the flapping wing. Secondly, an experimental model of the flapping wing aircraft has been built a...

At present, the production lines of mobile phones are mainly manual and semi-automatic. Robots are the most important tools used to improve the intelligence level of industry production. The design of an intelligent robotic assembly system is presented in this paper, which takes the assembly of screen components and shell components as examples. Th...