Robot manipulators are often tasked with working in environments with vibrations and are subject to load uncertainty. Providing an accurate tracking control design with implementable torque input for these robots is a complex topic. This paper presents two approaches to solve this problem. The approaches consider joint space tracking control design in the presence of nonlinear uncertain torques caused by external vibration and payload variation. The properties of the uncertain torques are used in both approaches. The first approach is based on the boundedness property, while the second approach considers the differentiability and boundedness together. The controllers derived from each approach differ from the perspectives of accuracy, control effort, and disturbance properties. A Lyapunov-based analysis is utilized to guarantee the stability of the control design in each case. Simulation results validate the approaches and demonstrate the performance of the controllers. The derived controllers show stable results at the cost of the mentioned properties.
Hook-Based Aerial Payload Grasping from a Moving Platform
Systems and Control Lab, HUN-REN Institute for Computer Science and Control（系统与控制实验室，HUN-REN计算机科学与控制研究所）；National Laboratory for Autonomous Systems（自主系统国家实验室）；Control Systems Group of the Eindhoven University of Technology（埃因霍温理工大学控制系统组）
Vibration Suppression in Collaborative Flexible Payload Manipulation Using Passive Force Control
VTT Technical Research Centre of Finland Ltd（芬兰VTT技术研究中心）；RP Technical University of Kaiserslautern（凯泽斯劳滕RP工业大学）；UK Atomic Energy Authority（英国原子能管理局）；University of Oulu（奥卢大学）
Payload-specific vibration control may be suitable for a particular task but lacks generality and transferability required for adapting to the various payload. Self-decoupling and robust vibration control are the crucial problems to achieve payload-agnostic vibration control. However, there are problems still unsolved. In this article, we present a maglev vibration isolation platform (MVIP), which aims to attenuate vibration in the payload-agnostic task under a dynamic environment. Since efforts trying to suppress disturbance will encounter inevitable coupling problems, we analyzed the reasons…
Imperial College London（帝国理工学院）；Institut Teknologi Bandung（万隆理工学院）
Soft robotic manipulators are attractive for a range of applications such as medical interventions or industrial inspections in confined environments. A myriad of soft robotic manipulators have been proposed in the literature, but their designs tend to be relatively similar, and generally offer a relatively low force. This limits the payload they can carry and therefore their usability. A comparison of force of the different designs is not available under a common framework, and designs present different diameters and features that make them hard to compare. In this paper, we present the desig…
This paper presents a method to control a manipulator system grasping a rigid-body payload so that the motion of the combined system in consequence of externally applied forces to be the same as another free-floating rigid-body (with different inertial properties). This allows zero-g emulation of a scaled spacecraft prototype under the test in a 1-g laboratory environment. The controller consisting of motion feedback and force/moment feedback adjusts the motion of the test spacecraft so as to match that of the flight spacecraft, even if the latter has flexible appendages (such as solar panels)…
Impedance and Stability Targeted Adaptation for Aerial Manipulator with Unknown Coupling Dynamics
Robotics Research Center, International Institute of Information Technology Hyderabad (IIIT-H)（印度海得拉巴国际信息技术学院机器人研究中心）；The University of Manchester（曼彻斯特大学）；Southeast University（东南大学）
In this paper, we consider the tracking control problem for robot manipulators which are affected by constant bounded disturbances. Three control schemes are applied for the problem, which composed of integral action and tracking controllers. The goal is improving the accuracy of tracking procedure for a robot manipulator to track a specified reference signal in the presence of constant bounded disturbances. Inverse dynamics controller, improved Lyapunov-based controller with integral action and discontinuous Lyapunov-based controller are three schemes that are evaluated in this paper. Third o…
Research Center for Intelligent Robotics, School of Automation, Northwestern Polytechnical University（智能机器人研究中心，自动化学院，西北工业大学）；Research Center for Intelligent Robotics, Shaanxi Province Innovation Team of Intelligent Robotic Technology, School of Astronautics, Northwestern Polytechnical University（智能机器人研究中心，陕西省智能机器人技术创新团队，航天学院，西北工业大学）
Multi-robot Aerial Soft Manipulator For Floating Litter Collection
GRVC Robotics Lab, Escuela Tecnica Superior de Ingenieria, Universidad de Sevilla（塞维利亚大学技术与工程学院机器人实验室）；Robotics and Mechatronics Department, Electrical Engineering, Mathematics, and Computer Science (EEMCS) Faculty, University of Twente（特文特大学机器人与机电部门）；Inria, Univ. Rennes, CNRS, IRISA（法国国家信息与自动化技术研究院（Inria））；Department of Computer, Control and Management Engineering, Sapienza University of Rome（罗马大学计算机、控制与管理工程系）
ETH Zurich（苏黎世联邦理工学院）；The Sapienza University of Rome（罗马第一大学）；The University of Tokyo（东京大学）
Soft robots are made of compliant materials and perform tasks that are challenging for rigid robots. However, their continuum nature makes it difficult to develop model-based control strategies. This work presents a robust model-based control scheme for soft continuum robots. Our dynamic model is based on the Euler-Lagrange approach, but it uses a more accurate description of the robot's inertia and does not include oversimplified assumptions. Based on this model, we introduce an adaptive sliding mode control scheme, which is robust against model parameter uncertainties and unknown input distu…
Bowling Green State University（鲍灵格林州立大学）；University of Ottawa（渥太华大学）；Machine Intelligence Research Labs（机器智能研究实验室）
The paper introduces an interactive machine learning mechanism to process the measurements of an uncertain, nonlinear dynamic process and hence advise an actuation strategy in real-time. For concept demonstration, a trajectory-following optimization problem of a Kinova robotic arm is solved using an integral reinforcement learning approach with guaranteed stability for slowly varying dynamics. The solution is implemented using a model-free value iteration process to solve the integral temporal difference equations of the problem. The performance of the proposed technique is benchmarked against…
Prognostic Framework for Robotic Manipulators Operating Under Dynamic Task Severities
School of Industrial and Systems Engineering, Georgia Institute of Technology（工业与系统工程系，佐治亚理工学院）；Department of Mechanical and Aerospace Engineering, University of California Davis（机械与航空航天工程系，加州大学戴维斯分校）
This paper presents a combined mu-synthesis PID control scheme, employing a frequency separation paradigm, for a recently proposed novel active suspension, the Parallel Active Link Suspension (PALS). The developed mu-synthesis control scheme is superior to the conventional H-infinity control, previously designed for the PALS, in terms of ride comfort and road holding (higher frequency dynamics), with important realistic uncertainties, such as in vehicle payload, taken into account. The developed PID control method is applied to guarantee good chassis attitude control capabilities and minimizat…
Adaptive Gravity Compensation Control of a Cable-Driven Upper-Arm Soft Exosuit
Birla Institute of Technology and Science Pilani（皮拉尼贝拉理工学院）；PricewaterhouseCoopers（普华永道）；Indian Institute of Technology Delhi（印度理工学院德里分校）；All India Institute of Medical Sciences（全印医学科学学院）
Manipulation and grasping with unmanned aerial vehicles (UAVs) currently require accurate positioning and are often executed at reduced speed to ensure successful grasps. This is due to the fact that typical UAVs can only accommodate rigid manipulators with few degrees of freedom, which limits their capability to compensate for disturbances caused by the vehicle positioning errors. Moreover, UAVs have to minimize external contact forces in order to maintain stability. Biological systems, on the other hand, exploit softness to overcome similar limitations, and leverage compliance to enable aggr…
Fused deposition modeling (FDM) using mobile robots instead of the gantry-based 3D printer enables additive manufacturing at a larger scale with higher speed. This introduces challenges including accurate localization, control of the printhead, and design of a stable mobile manipulator with low vibrations and proper degrees of freedom. We proposed and developed a low-cost non-holonomic mobile 3D printing system guided by a projector via learning-based visual servo-ing. It requires almost no manual calibration of the system parameters. Using a regular top-down projector without any expensive ex…
Time-delay Control Using a New Nonlinear Adaptive Law for Cable-Driven Robots
Nanjing University of Aeronautics and Astronautics（南京航空航天大学）；Donghai Laboratory（东海实验室）；China Academy of Machinery Beijing Research Institute of Mechanical and Electrical Technology Co., Ltd.（中国机械工业北京机电技术研究院有限公司）
Contact-Aware Safety in Soft Robots Using High-Order Control Barrier and Lyapunov Functions
Laboratory for Information and Decision Systems, Massachusetts Institute of Technology（信息与决策系统实验室，麻省理工学院）；Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology（计算机科学与人工智能实验室，麻省理工学院）；Cognitive Robotics, Delft University of Technology（认知机器人学，代尔夫特理工大学）；Robotics Engineering Department, Worcester Polytechnic Institute（机器人工程系，沃斯特理工学院）
