关键词： Spatial variables control   Aerospace control   Control system analysis and synthesis methods   Stability in control theory   Self-adjusting control systems   Nonlinear control systems  

摘要： This paper presents the design, analysis, and implementation of an adaptive backstepping controller for underactuated quadrotors to track time-varying trajectories with parameter uncertainties. Quadrotor systems are subject to complicated non-linearity and coupling dynamics, so the ignorance of parameter uncertainties may cause performance degradation and even instability. With the concept of nominal input, the uncertain mass and inertia are decoupled from the lifting force and moment torque. By utilizing the backstepping technique, the design procedure with adaptive laws for dynamic parameters is proposed to ensure stability and convergence of tracking errors to the origin asymptotically. The proposed control scheme is extended to control a quadrotor with velocity motor input while the motor coefficients and geometric parameters are handled by the adaptive laws. A trajectory generation for the proposed adaptive tracking controller is addressed subsequently. The proposed controller requires only the position and orientation of the quadrotor with the twice-differentiable trajectories, while previous work demanded acceleration information. Simulation and experimental results are illustrated to show the efficacy of tracking performance for object transportation.

关键词： 3D printing   actuators   self‐   healing   shape memory polymers   soft robotics  

摘要： Soft robotics is a growing field of research, focusing on constructing motor-less robots from highly compliant materials, some are similar to those found in living organisms. Soft robotics has a high potential for applications in various fields such as soft grippers, actuators, and biomedical devices. 3D printing of soft robotics presents a novel and promising approach to form objects with complex structures, directly from a digital design. Here, recent developments in the field of materials for 3D printing of soft robotics are summarized, including high-performance flexible and stretchable materials, hydrogels, self-healing materials, and shape memory polymers, as well as fabrication of all-printed robots (multi-material printing, embedded electronics, untethered and autonomous robotics). The current challenges in the fabrication of 3D printed soft robotics, including the materials available and printing abilities, are presented and the recent activities addressing these challenges are also surveyed.

关键词： Educational robotics   Teacher training   Improving classroom teaching   Digital technologies  

摘要： The emergence of Educational Robotics (ER) and its rapid spread across all levels of education in recent years has drawn attention to the need for further training in this discipline. In this study we discuss the panorama of teacher training research in ER and make recommendations for institutions that intend to implement ER teacher training programs. We explore three databases that include publications in ER teacher training and select 38 publications for analysis. We discuss these publications with special emphasis on requirements, durations, trainer and trainee profiles, pedagogical approaches and best practices. Our main findings are the lack of uniformity regarding the duration and requirements of training programs and the fact that information on trainer and trainee profiles is not always documented. ER teacher training programs are often not founded on theory. When they are based on pedagogical principles, however, these are usually constructivism/constructionism, inquiry-based learning or project-based learning. The most prominent best practices for ER teacher training fall into five categories: collaboration, materials, pedagogy, practice and feedback/support. Our recommendations will help to improve the content, structure and implementation of future ER teacher training programs and the reliability and generalizability of research results and design.

关键词： actuators   fibers   fabrics   power sources   sensors   soft robotics  

摘要： Soft robotics inspired by the movement of living organisms, with excellent adaptability and accuracy for accomplishing tasks, are highly desirable for efficient operations and safe interactions with human. With the emerging wearable electronics, higher tactility and skin affinity are pursued for safe and user-friendly human-robot interactions. Fabrics interlocked by fibers perform traditional static functions such as warming, protection, and fashion. Recently, dynamic fibers and fabrics are favorable to deliver active stimulus responses such as sensing and actuating abilities for soft-robots and wearables. First, the responsive mechanisms of fiber/fabric actuators and their performances under various external stimuli are reviewed. Fiber/yarn-based artificial muscles for soft-robots manipulation and assistance in human motion are discussed, as well as smart clothes for improving human perception. Second, the geometric designs, fabrications, mechanisms, and functions of fibers/fabrics for sensing and energy harvesting from the human body and environments are summarized. Effective integration between the electronic components with garments, human skin, and living organisms is illustrated, presenting multifunctional platforms with self-powered potential for human-robot interactions and biomedicine. Lastly, the relationships between robotic/wearable fibers/fabrics and the external stimuli, together with the challenges and possible routes for revolutionizing the robotic fibers/fabrics and wearables in this new era are proposed.

关键词： Computer science education   Professional development   Elementary school curriculum   Computer science unplugged   Educational robotics   Curriculum implementation  

摘要： Integrating computer science (CS) into school curricula has become a worldwide preoccupation. Therefore, we present a CS and Robotics integration model and its validation through a large-scale pilot study in the administrative region of the Canton Vaud in Switzerland. Approximately 350 primary school teachers followed a mandatory CS continuing professional development program (CPD) of adapted format with a curriculum scaffolded by instruction modality. This included CS Unplugged activities that aim to teach CS concepts without the use of screens, and Robotics Unplugged activities that employed physical robots, without screens, to learn about robotics and CS concepts. Teachers evaluated positively the CPD and their representation of CS improved. Voluntary adoption rates reached 97% during the CPD and 80% the following year. These results combined with the underpinning literature support the generalisability of the model to other contexts.

关键词： robot industry   medical robotics   technology commercialization   data mining  

摘要： The robot industry is a key field of the Fourth Industrial Revolution. Among them, the interest in medical robotics is increasing due to aging and changes in living patterns. In the medical robotics market, a small number of companies dominate the market, causing problems such as increased costs. To prevent such problems, various companies need to enter the market. In order for new entrants to secure technology efficiently, technology commercialization such as technology transfer is necessary. However, in the field of medical robotics, few companies have major skills and perform most of the technology transfer. In this paper, we propose a model for providing technology commercialization information to new entrants. The experimental data uses patents related to vascular surgery robots registered in the USPTO. As a result of the experiment, high applicants have advanced into various countries in order to secure market power, and have a technique for analyzing the internal image of the body mainly through endoscopy.

关键词： buckling   mechanical instabilities   programmable matter   snap through   soft robotics  

摘要： The rapidly expanding field of soft robotics has provided multiple examples of how entirely soft machines and actuators can outperform conventional rigid robots in terms of adaptability, maneuverability, and safety. Unfortunately, the soft and flexible materials used in their construction impose intrinsic limitations on soft robots, such as low actuation speeds and low output forces. Nature offers multiple examples where highly flexible organisms exploit mechanical instabilities to store and rapidly release energy. Guided by these examples, researchers have recently developed a variety of strategies to overcome speed and power limitations in soft robotics using mechanical instabilities. These mechanical instabilities provide, through rapid transitions from structurally stable states, a new route to achieve high output power amplification and attain impressive actuation speeds. Here, an overview of the literature related to the development of soft robots and actuators that exploit mechanical instabilities to expand their actuation speed, output power, and functionality is presented. Additionally, strategies using structural phase transitions to address current challenges in the area of soft robotic control, sensing, and actuation are discussed. Approaches using instabilities to create entirely soft logic modules to imbue soft robots with material intelligence and distributed computational capabilities are also reviewed.

关键词： dentistry   robots   robotics  

摘要： Robotics is a disruptive technology that will change diagnostics and treatment protocols in dental medicine. Robots can perform repeated workflows for an indefinite length of time while enhancing the overall quality and quantity of patient care. Early robots required a human operator, but robotic systems have advanced significantly over the past decade, and the latest medical robots can perform patient intervention or remote monitoring autonomously. However, little research data on the therapeutic reliability and precision of autonomous robots are available. The present paper reviews the promise and practice of robots in dentistry by evaluating published work on commercial robot systems in dental implantology, oral and maxillofacial surgery, prosthetic and restorative dentistry, endodontics, orthodontics, oral radiology as well as dental education. In conclusion, this review critically addresses the current limitations of dental robotics and anticipates the potential future impact on oral healthcare and the dental profession.

关键词： Legged robot   Leg hydraulic drive system (LHDS)   Dynamics compensation   Impedance based motion control  

摘要： Aimed at the negative effect of dynamics characteristics of leg hydraulic drive system (LHDS) on the accuracy of motion control of the hydraulic drive legged robot, a dynamics compensation control method is proposed. First, according to the mechanical structure of LHDS, the kinematics and statics models of LHDS are analyzed and obtained respectively. Based on the principle of force-based impedance control of LHDS, an impedance based motion control simulation model of LHDS is built and analyzed. The simulation results show that the dynamics characteristics have a great influence on the accuracy of impedance based motion control. Then, a dynamics compensation method considering gravity and inertia force is proposed to solve this problem. Finally, the effect of the dynamics compensation method is verified on the robot single leg test platform. The experimental results show that the compensation method reduces the negative effect of the dynamics characteristics of LHDS on impedance based motion control accuracy, and the position tracking accuracy of the robot's foot end can be improved by more than 65%. The theory proposed in this paper provides a theoretical basis for the motion control of the whole robot prototype. (C) 2020 Elsevier B.V. All rights reserved.