Da Sun

Efficiently coordinating multiple robotic arms is vital for secure and optimal operation in a shared workspace. This requires not only successful task completion but also minimizing collision risks from overlapping movements. Introducing real-time motion modulation adds an extra layer of challenge to this coordination task. In this article, we intr...

Current path-tracking trajectory planning methods intrinsically suffer from a heavy computational burden, hindering them from modern autonomous robotic applications requiring real-time reactivity. To achieve flexible, accurate, and efficient motions, this article proposes a real-time trajectory planning framework for time-efficient path tracking. F...

In this article, we propose a new method for multi-robot systems to have reactive responses to various collision scenarios in real time. This method contains a novel p-norm approximation-based reactive approach, which allows multiple robots to avoid mutual collisions or to adapt to the collisions with intelligently regulated force. Compared with ex...

Manipulability ellipsoid on the Riemannian mani- fold serves as an effective criterion to analyze, measure, and control the dexterous performance of robots. For asymmetric bilateral telerobotics, due to the different structures of master and slave robots, it is difficult or even impossible for the operator to manually regulate the manipulability of...

Environmental collision is a challenging issue in human-robot collaboration. This article proposes a novel fuzzy cluster-based framework for robots to have reactive responses to various environmental collision scenarios. This framework makes four contributions: First, a fuzzy cluster-based environmental collision detection algorithm is developed to...

This article studies group-wise point set registration and makes the following contributions: ``FuzzyGReg'', which is a new fuzzy cluster-based method to register multiple point sets jointly, and ``FuzzyQA'', which is the associated quality assessment to check registration accuracy automatically. Given a group of point sets, FuzzyGReg creates a mod...

Imitation learning is an important direction in the area of robot skill learning. It provides a user-friendly and straightforward solution to transfer human demonstrations to robots. In this article, we integrate fuzzy theory into imitation learning to develop a novel method called Type-2 Fuzzy Model-based Movement Primitives (T2FMP). In this metho...

This paper studies the fuzzy cluster-based point set registration (FuzzyPSReg). First, we propose a new metric based on Gustafson-Kessel (GK) fuzzy clustering to measure the alignment of two point clouds. Unlike the metric based on fuzzy c-means (FCM) clustering in our previous work, the GK-based metric includes orientation properties of the point...

This study proposes a new shared mixed reality (MR)-bilateral telerobotic system. The main contribution of this study is to combine MR teleoperation and bilateral teleoperation, which takes advantage of the two types of teleoperation and compensates for each other's drawbacks. With this combination, the proposed system can address the asymmetry iss...

The asymmetry in bilateral teleoperation, i.e., thedifferences of mechanical structures, sizes and number of jointsbetween the master and slave robots, can introduce kinematicsredundancy and workspace inequality problems. In this paper,a novel shared autonomy control strategy is proposed for han-dling the asymmetry of bilateral teleoperation, which...

This study presents a new point set registration method to align 3D range scans. Fuzzy clusters are utilized to represent a scan, and the registration of two given scans is realized by minimizing a fuzzy weighted sum of the distances between their fuzzy cluster centers. This metric has a broad basin of convergence and is robust to noise. Moreover,...

Abstract—This paper proposes a new single master bimanual teleoperation (SMBT) system with an efficient position, orientation and force regulation strategy. Unlike many existing studies that solely support motion synchronization, the first contribution of the proposed work is to propose a solution for orientation regulation when several slave robot...

Virtual reality (VR) is regarded as a useful tool for teleoperation systems and provides operators with immersive visual feedback on the robot and the environment. However, without any haptic feedback or physical constructions, VR-based teleoperation systems normally suffer from poor maneuverability, and operational faults may be caused in some fin...

This paper firstly develops a novel force observer using Type-2 Fuzzy Neural Network (T2FNN)-basedMoving Horizon Estimation (MHE) to estimate external force/torque information and simultaneouslyfilter out the system disturbances. Then, by using the proposed force observer, a new bilateralteleoperation system is proposed that allows the slave indust...

In order to better handle the coupling effects when controlling multiple-input multiple-output (MIMO) systems, taking the decentralized control structure as the basis, this paper proposes a sparse control strategy and a decoupling control strategy. Type-1 and type-2 Takagi-Sugeno (T-S) fuzzy models are used to describe the MIMO system, and the rela...

This article presents an approach for assisted teleoperation of a robot arm, formulated within a real-time stack-of-tasks (SoT) whole-body motion control framework. The approach leverages the hierarchical nature of the SoT framework to integrate operator commands with assistive tasks, such as joint limit and obstacle avoidance or automatic gripper...

This paper develops an innovative multilateral teleoperation system with two haptic devices on the master side and a newly designed reconfigurable multi-fingered robot on the slave side. A novel nonsingular fast terminal sliding-mode algorithm, together with varying dominance factors for cooperation, is proposed to offer this system's fast position...

Interaction measure determines decentralized and sparse control configurations for multivariable process control. This paper investigates interval type-2 Takagi-Sugeno fuzzy (IT2TSF) model based interaction measures using two different criteria, one is controllability and observability gramians, the other is relative normalized gain array (RNGA). T...

This paper develops a novel shared control scheme for online-switching tele-operated and autonomous system with time-varying delays. Type-2 Takagi-Sugeno (T-S) fuzzy model is used to describe the dynamics of master and slave robots in this system. A novel non-singular fast terminal siding mode (NFTSM)-based algorithm combined with an extended wave-...

This paper develops data-driven Type-2 Takagi-Sugeno (T-S) fuzzy modeling and control for bilateral teleoperation with dynamic uncertainties and time-varying delays. The Type-2 T-S fuzzy model identified based on input-output data samples describes the nonlinear teleoperation system by a weighted sum of a group of linear local models, which offers...

Effective model is a novel tool for decentralized controller design to handle the interconnected interactions in a multi-input-multi-output (MIMO) process. In this paper, Type-1 and Type-2 effective Takagi-Sugeno fuzzy models (ETSM) are investigated. By means of the loop pairing criterion, simple calculations are given to build Type-1/Type-2 ETSMs...

A novel approach applying the extended prescribed performance control (PPC) and the wave-based time domain passivity approach (wave-based TDPA) to teleoperation systems is proposed. With the extended PPC, a teleoperation system can synchronize position, velocity and force. Moreover, by combining with the extended wave-based TDPA, the overall system...

In this paper, a novel neural network (NN)-based four-channel wave-based time domain passivity approach (TDPA) is proposed for a teleoperation system with time-varying delays. The designed wave-based TDPA aims to robustly guarantee the channels passivity and provide higher transparency than the previous power-based TDPA. The applied NN is used to e...

In this paper, a novel control approach is presented to improve the stability and transparency of the nonlinear bilateral teleoperation system with time delays, where a four-channel (4-CH) architecture using modified wave reflection reduction transformation is explored in order to guarantee the passivity of the communication channels in the nonline...

A novel control algorithm based on the modified wave-variable controllers is proposed to achieve accurate position synchronization and reasonable force tracking of the nonlinear single-master-multiple-slave teleoperation system and simultaneously guarantee overall system’s stability in the presence of large time-varying delays. The system stability...

An innovative wave-based Time Domain Passivity Approach (TDPA) applied to a four-channel (4-CH) nonlinear teleoperation system is proposed. The primary objective of this approach is to enhance system transparency while maintaining stability in the presence of random time delays. The system stability for different scenarios of human and environment...

Teleoperation systems allow an operator to perform complex tasks in a remote environment. Stability of a bilateral teleoperation system is quite sensitive to time delays. One of the methods to guarantee the stability of bilateral telerobotics in the presence of time delays is wave variable control. A review of various applications of wave variable...

Stability and transparency are two critical indices of bilateral teleoperation systems. The wave variable method is a conservative approach to robustly guarantee system passivity under arbitrary constant time delays. However, the wave-variable-based reflection is an intrinsic problem in this method because it can significantly degrade system transp...