关键词： Dynamics   force   position hybrid control   point-contact constraints   redundant actuation   torque distribution  

摘要： A 4-DOF redundantly actuated parallel robot (RAPR) for jaw movement achieved by adding two point-contact constraints (higher-kinematic-pairs, HKPs) is presented. The inverse dynamics and driving force optimization model based on pseudo-inverse method are established. In order to overcome the disequilibrium of driving forces of the redundant chains caused by inclusion of point-contact constraints, an optimized torque distribution based force/position hybrid control (OTDFP control) method for trajectory tracking is proposed for this RAPR. Experiments are carried out to evaluate the OTDFP control. Comparison with the conventional position control is performed, showing that the OTDFP control can reduce torque fluctuation and tracking errors of the RAPR. The chewing experiment of silicone shows the RAPR is not only able to track mandibular movement, but also able to emulate chewing force and temporomandibular joint (TMJ) force under the OTDFP control.

关键词： *Integrated circuits   *Robots   *Artificial intelligence   Aggregation (Robotics)   Neural computers  

摘要： The article focuses on the ultra-low-power neural-network chip, developed by researchers at the Georgia Institute of Technology, which could let palm-sized robots collaborate and learn from their experiences. It states that the application-specific integrated circuit could help intelligent swarm robots operate for hours.

关键词： elastomeric prepregs   fluid-driven robots   soft robotics   viscosity measurements  

摘要： Typically, soft robots that are driven with compressed air consist of two parts which are bonded together, a top and a strain-limiting bottom part. This communication describes the possibility to simplify the manufacturing process by using textile semi-finished products preimpregnated with liquid elastomer (prepregs) as the strain-limiting part, which can be stored at low temperatures with significant slower cross-linking reaction. For this, in long-term tests, three typical elastomers (Elastosil M 4601, Ecoflex 00-30, and Sylgard 184) are stored at -25 degrees C, and in a weekly cycle over 12 weeks, the viscosity is measured to determine the curing characteristics. It turns out that Elastosil M 4601 and Sylgard 184 are suitable for this application. For comparison, short-term viscosity measurements are conducted at room temperature in a 10 min cycle. The impregnability of several textiles (polyester/cotton blended fabric, nylon fabric, fleece, and flax fabric) is tested with the suitable elastomers. The applicability of prepregs for soft robotic applications is demonstrated by manufacturing soft bending actuators with various textile-elastomer combinations.

关键词： emergency response   terrestrial robotics   wheeled robots  

摘要： European Robotics League (ERL) Emergency Robots is an outdoor robotics contest focusing on multidomain emergency response scenarios. In this context, the deployed robots are expected to fulfill land, underwater, and flying cooperative tasks which emulate real-world situations inspired by the 2011 Fukushima accident. Participation of the Tuscany Robotics Team at ERL Emergency Robots 2017 was deeply affected by damage to (and resulting unavailability of) the unmanned ground vehicle to be used in the competition. This damage occurred 3 days before the challenge. An entirely new working mobile platform was built from scratch using a low-cost chassis. It was able to compete with the other participants in the challenge and achieved various tasks (similar to 83% of the tasks completed by the best performer). The paper provides a complete description of the work carried out and the system used during the competition. The development was based on low-cost solutions, in particular: Adoption of open-hardware and open-software technology, providing cheap and fast-prototyping solutions. Use of smartphones, allowing sophisticated sensors to be exploited in an affordable way. Employment of Cloud infrastructures, to reduce the computational burden of offloading heavy processes. Results of this experience represent a concrete demonstration, showing that even low-cost solutions can achieve complex tasks, such as those required for the European robotic competition. The presented lessons learned aim to provide guidelines useful for reacting to unexpected events. Finally, the team was honored with the Creativity Award "for building a land robot from scratch in less than 2 days when their ground platform broke."

关键词： Robotics  

摘要： The human mind has been one of the most intriguing enigmas since time immemorial. Understanding the brain and the secrets of its success is multidisciplinary research that involves a range of domains, such as engineering, computing, data science, neuroscience, and cognitive science. Robotics is almost the ideal platform for implementing our understanding of the brain on a physical system, and, at the same time, we may use it to further our understanding through the examination and testing of the robots we develop. © 1988-2012 IEEE.

关键词： graphene oxide templating metal oxide origamis   reconfigurable metamaterials   multifunctional robotic backbones   soft robotics  

摘要： Origami structures have been widely applied in various technologies especially in the fields of soft robotics. Metal oxides (MOs) have recently emerged as unconventional backbone materials for constructing complex origamis with distinct functionalities. However, the MO origami structures reported in the literature were rigid and not deformable, thus limiting their applications to soft robotics. Herein, we reported a graphene oxide (GO) enabled templating synthesis to produce complex MO origami structures from their paper origami templates with high structural replication. The MO origami structures were next stabilized with elastomer, and the MO elastomer origamis were able to be adapted into multiple actuation systems (including magnetic fields, shape-memory alloys, and pneumatics) for the fabrication of MO origami robots. Compared with conventional paper origami robots, the MO robots were lightweight, mechanically compliant, fire-retardant, magnetic responsive, and power efficient. We further demonstrated the legendary phoenix-fire-reborn concept in the soft robotics fields: a paper origami robot sacrificed itself in a fire scene and transformed itself into a downsized Al2O3 robot;the Al2O3 robot was able to crawl through a narrow tunnel where the original paper robot was unfit. These MO reconfigurable origamis provide an expanded material library for building soft robotics, and the functionalities of MO robots can be systematically engineered via the intercalation of various metal ions during the GO-enabled synthesis.

关键词： Continuum robot   soft robot   forward dynamics  

摘要： The dynamic equations of many continuum and soft robot designs can be succinctly formulated as a set of partial differential equations (PDEs) based on classical Cosserat rod theory, which includes bending, torsion, shear, and extension. In this work we present a numerical approach for forward dynamics simulation of Cosserat-based robot models in real time. The approach implicitly discretizes the time derivatives in the PDEs and then solves the resulting ordinary differential equation (ODE) boundary value problem (BVP) in arc length at each timestep. We show that this strategy can encompass a wide variety of robot models and numerical schemes in both time and space, with minimal symbolic manipulation required. Computational efficiency is gained owing to the stability of implicit methods at large timesteps, and implementation is relatively simple, which we demonstrate by providing a short MATLAB-coded example. We investigate and quantify the tradeoffs associated with several numerical subroutines, and we validate accuracy compared with dynamic rod data gathered with a high-speed camera system. To demonstrate the method's application to continuum and soft robots, we derive several Cosserat-based dynamic models for robots using various actuation schemes (extensible rods, tendons, and fluidic chambers) and apply our approach to achieve real-time simulation in each case, with additional experimental validation on a tendon robot. Results show that these models capture several important phenomena, such as stability transitions and the effect of a compressible working fluid.

关键词： Tethered exoskeletons   End-effector devices   Untethered exoskeletons   Gait rehabilitation  

摘要： Improving walking function is a desirable outcome in rehabilitation and of high importance for social and vocational reintegration for persons with neurologic-related gait impairment. Robots for lower limb gait rehabilitation are designed principally to help automate repetitive labor-intensive training during neurorehabilitation. These include tethered exoskeletons, end effector devices, untethered exoskeletons, and patient-guided suspension systems. This article reviews the first 3 categories and briefly mentions the fourth. Research is needed to further define the therapeutic applications of these devices. Additional technical improvements are expected regarding device size, controls, and battery life for untethered devices.

摘要： The article reports that Daimler Trucks has acquire majority stake in Torc Robotics to brings highly automated trucks to U.S. highways and presents views of Martin Daum, chief executive officer (CEO) at Daimler Trucks, on the same.

关键词： Robot Operating System   Package management   Software ecosystems  

摘要： ROS, the Robot Operating System, offers a core set of software for operating robots that can be extended by creating or using existing packages, making it possible to write robotic software that can be reused on different hardware platforms. With thousands of packages available per stable distribution, encapsulating algorithms, sensor drivers, etc., it is the de facto middleware for robotics. Like any software ecosystem, ROS must evolve in order to keep meeting the requirements of its users. In practice, packages may end up being abandoned between releases: no one may be available to update a package, or newer packages offer similar functionality. As such, we wanted to identify and understand the evolution challenges faced by the ROS ecosystem. In this article, we report our findings after interviewing 19 ROS developers in depth, followed by a focus group (4 participants) and an online survey of 119 ROS community members. We specifically focused on the issues surrounding package reuse and how to contribute to existing packages. To conclude, we discuss the implications of our findings, and propose five recommendations for overcoming the identified issues, with the goal of improving the health of the ROS ecosystem. (C) 2019 Elsevier Inc. All rights reserved.