Development of an Amphibious Turtle-Inspired Spherical Mother Robot

Robots play an important role in underwater monitoring and recovery operations, such as pollution detection, submarine sampling and data collection, video mapping, and object recovery in dangerous places. However, regular-sized robots may not be suitable for applications in some restricted underwater environments. Accordingly, in previous research we designed several novel types of bio-inspired microrobots using Ionic Polymer Metal Composite （IPMC） and Shape Memory Alloy （SMA） ac- tuators. These microrobots possess some attributes of compact structure, multi-functionality, flexibility, and precise positioning. However, they lack the attributes of long endurance, stable high speed, and large load capacity necessary for real-world appli- cations. To overcome these disadvantages, we proposed a mother-son robot system, composed of several microrobots as sons and a newly designed amphibious spherical robot as the mother. Inspired by amphibious turtles, the mother robot was designed with a spherical body and four legs with two Degrees of Freedom （DOF）. It is actuated by four vectored water-jet propellers and ten servomotors, and it is capable of walking on land and cruising underwater. We analysed the mother robot＇s walking and underwater cruising mechanisms, constructed a prototype, and carried out a series of experiments to evaluate its amphibious motions. Good motion performance was observed in the experiments.     

Role of expressive behaviour for robots that learn from people

Robotics has traditionally focused on developing intelligent machines that can manipulate and interact with objects. The promise of personal robots, however, challenges researchers to develop socially intelligent robots that can collaborate with people to do things. In the future, robots are envisioned to assist people with a wide range of activities such as domestic chores, helping elders to live independently longer, serving a therapeutic role to help children with autism, assisting people undergoing physical rehabilitation and much more. Many of these activities shall require robots to learn new tasks, skills and individual preferences while ‘on the job’ from people with little expertise in the underlying technology. This paper identifies four key challenges in developing social robots that can learn from natural interpersonal interaction. The author highlights the important role that expressive behaviour plays in this process, drawing on examples from the past 8 years of her research group, the Personal Robots Group at the MIT Media Lab.     

Design and Kinematic Analysis of a Novel Humanoid Robot Eye Using Pneumatic Artificial Muscles

This paper proposed a novel humanoid robot eye, which is driven by six Pneumatic Artificial Muscles （PAMs） and rotates with 3 Degree of Freedom （DOF）. The design of the mechanism and motion type of the robot eye are inspired by that of human eyes. The model of humanoid robot eye is established as a parallel mechanism, and the inverse-kinematic problem of this flexible tendons driving parallel system is solved by the analytical geometry method. As an extension, the simulation result for saccadic movement is presented under three conditions. The design and kinematic analysis of the prototype could be a sig- nificant step towards the goal of building an autonomous humanoid robot eye with the movement and especially the visual functions similar to that of human.     

Biomimetic vibrissal sensing for robots

Active vibrissal touch can be used to replace or to supplement sensory systems such as computer vision and, therefore, improve the sensory capacity of mobile robots. This paper describes how arrays of whisker-like touch sensors have been incorporated onto mobile robot platforms taking inspiration from biology for their morphology and control. There were two motivations for this work: first, to build a physical platform on which to model, and therefore test, recent neuroethological hypotheses about vibrissal touch; second, to exploit the control strategies and morphology observed in the biological analogue to maximize the quality and quantity of tactile sensory information derived from the artificial whisker array. We describe the design of a new whiskered robot, Shrewbot, endowed with a biomimetic array of individually controlled whiskers and a neuroethologically inspired whisking pattern generation mechanism. We then present results showing how the morphology of the whisker array shapes the sensory surface surrounding the robot's head, and demonstrate the impact of active touch control on the sensory information that can be acquired by the robot. We show that adopting bio-inspired, low latency motor control of the rhythmic motion of the whiskers in response to contact-induced stimuli usefully constrains the sensory range, while also maximizing the number of whisker contacts. The robot experiments also demonstrate that the sensory consequences of active touch control can be usefully investigated in biomimetic robots.     

藤壶附着机理及其粘胶蛋白的研究进展

海洋固着动物分泌的粘胶蛋白在潮湿环境下可以抵御水的阻力而发挥粘性,成为当今生物医学和仿生学领域开发高性能材料的关键候选材料。藤壶作为海洋污损生物之一,通过分泌的藤壶胶可以在水下牢固地附着在不同表面特性的基底材料上。目前,对藤壶的粘附过程已经有了较为深入的了解,但其水下粘附机制尚未特别清晰,还需进一步阐明。为此,本文对藤壶胶及其粘附过程的研究进展进行了综述,介绍了藤壶胶主要粘胶蛋白的研究进展、总结了藤壶胶蛋白的获取方式及其应用,最后提出了可能的研究要点和未来发展方向。     

Principles of goal-directed spatial robot navigation in biomimetic models

Mobile robots and animals alike must effectively navigate their environments in order to achieve their goals. For animals goal-directed navigation facilitates finding food, seeking shelter or migration; similarly robots perform goal-directed navigation to find a charging station, get out of the rain or guide a person to a destination. This similarity in tasks extends to the environment as well; increasingly, mobile robots are operating in the same underwater, ground and aerial environments that animals do. Yet despite these similarities, goal-directed navigation research in robotics and biology has proceeded largely in parallel, linked only by a small amount of interdisciplinary research spanning both areas. Most state-of-the-art robotic navigation systems employ a range of sensors, world representations and navigation algorithms that seem far removed from what we know of how animals navigate; their navigation systems are shaped by key principles of navigation in ‘real-world’ environments including dealing with uncertainty in sensing, landmark observation and world modelling. By contrast, biomimetic animal navigation models produce plausible animal navigation behaviour in a range of laboratory experimental navigation paradigms, typically without addressing many of these robotic navigation principles. In this paper, we attempt to link robotics and biology by reviewing the current state of the art in conventional and biomimetic goal-directed navigation models, focusing on the key principles of goal-oriented robotic navigation and the extent to which these principles have been adapted by biomimetic navigation models and why.     

Design of a Novel Exoskeleton with Passive Magnetic Spring Self-locking and Spine Lateral Balancing

This paper proposes a new upper-limb exoskeleton to reduce worker physical strain.The proposed design is based on a novel PRRRP(P-Prismatic;R-Revolute)kinematic chain with 5 passive Degrees of Freedom(DoF).Utilizing a magnetic spring,the proposed mechanism includes a specially designed locking mechanism that maintains any desired task posture.The proposed exoskeleton incorporates a balancing mechanism to alleviate discomfort and spinal torsional effects also helping in limb weight relief.This paper reports specific models and simulations to demonstrate the feasibility and effectiveness of the proposed design.An experimental characterization is performed to validate the performance of the mechanism in terms of forces and physical strain during a specific application consisting of ceiling-surface drilling tasks.The obtained results preliminarily validate the engineering feasibility and effectiveness of the proposed exoskeleton in the intended operation task thereby requiring the user to exert significantly less force than when not wearing it.     

Self-organisation and communication in groups of simulated and physical robots

In social insects, both self-organisation and communication play a crucial role for the accomplishment of many tasks at a collective level. Communication is performed with different modalities, which can be roughly classified into three classes: indirect (stigmergic) communication, direct interactions and direct communication. The use of stigmergic communication is predominant in social insects (e.g. the pheromone trails in ants), where, however, direct interactions (e.g. antennation in ants) and direct communication (e.g. the waggle dance in honey bees) can also be observed. Taking inspiration from insect societies, we present an experimental study of self-organising behaviours for a group of robots, which exploit communication to coordinate their activities. In particular, the robots are placed in an arena presenting holes and open borders, which they should avoid while moving coordinately. Artificial evolution is responsible for the synthesis in a simulated environment of the robot’s neural controllers, which are subsequently tested on physical robots. We study different communication strategies among the robots: no direct communication, handcrafted signalling and a completely evolved approach. We show that the latter is the most efficient, suggesting that artificial evolution can produce behaviours that are more adaptive than those obtained with conventional design methodologies. Moreover, we show that the evolved controllers produce a self-organising system that is robust enough to be tested on physical robots, notwithstanding the huge gap between simulation and reality.Electronic Supplementary Material Supplementary material is available for this article at     

Towards the molecular understanding of glycogen elongation by amylosucrase

Amylosucrase from Neisseria polysaccharea (AS) is a transglucosidase from the glycoside-hydrolase family 13 that catalyzes the synthesis of an amylose-like polymer from sucrose, without any primer. Its affinity towards glycogen is particularly noteworthy since glycogen is the best D-glucosyl unit acceptor and the most efficient activator (98-fold k(cat) increase) known for this enzyme. Glycogen-enzyme interactions were modeled starting from the crystallographic AS: maltoheptaose complex, where two key oligosaccharide binding sites, OB1 and OB2, were identified. Two maltoheptaose molecules were connected by an alpha-1,6 branch by molecular modeling to mimic a glycogen branching. Among the various docking positions obtained, four models were chosen based on geometry and energy criteria. Robotics calculations enabled us to describe a back and forth motion of a hairpin loop of the AS specific B'-domain, a movement that assists the elongation of glycogen branches. Modeling data combined with site-directed mutagenesis experiments revealed that the OB2 surface site provides an anchoring platform at the enzyme surface to capture the polymer and direct the branches towards the OB1 acceptor site for elongation. On the basis of the data obtained, a semiprocessive glycogen elongation mechanism can be proposed.     

Evolving locomotion for a 12-DOF quadruped robot in simulated environments

We demonstrate the power of evolutionary robotics (ER) by comparing to a more traditional approach its performance and cost on the task of simulated robot locomotion. A novel quadruped robot is introduced, the legs of which – each having three non-coplanar degrees of freedom – are very maneuverable. Using a simplistic control architecture and a physics simulation of the robot, gaits are designed both by hand and using a highly parallel evolutionary algorithm (EA). It is found that the EA produces, in a small fraction of the time that takes to design by hand, gaits that travel at two to four times the speed of the hand-designed one. The flexibility of this approach is demonstrated by applying it across a range of differently configured simulators.