A robust motion design technique for flexible-jointed manipulation systems

This paper presents a robust input shaping technique that significantly reduces (almost eliminates) the residual vibration of manipulation systems typified by a flexiblejointed robot manipulator. The technique consists of two stages. In the first stage, a ramp function is superimposed onto the main trajectory to be preshaped. In the second stage, the outcome of the first stage is convolved with a sequence of two impulses. The robustness of the technique to the uncertainties in the system natural frequency and damping ratio are quantified through simulation and experimental evaluation. Simulation and experimental results demonstrate that the technique is not only effective in reducing the residual vibrations, but also it is robust to the uncertainties of as high as∓35% from the ideal value of the system natural frequency. Further, it has been found that the proposed input shaping technique is insensitive to the uncertainties in the damping ratio. The results allow us to suggest that the proposed technique is versatile and robust enough to apply it to the motion design of any flexible-jointed manipulation system making a point-to-point motion

Actuators and sensors for application in agricultural robots: A review

In recent years, with the rapid development of science and technology, agricultural robots have gradually begun to replace humans, to complete various agricultural operations, changing traditional agricultural production methods. Not only is the labor input reduced, but also the production efficiency can be improved, which invariably contributes to the development of smart agriculture. This paper reviews the core technologies used for agricultural robots in non-structural environments. In addition, we review the technological progress of drive systems, control strategies, end-effectors, robotic arms, environmental perception, and other related systems. This research shows that in a non-structured agricultural environment, using cameras and light detection and ranging (LiDAR), as well as ultrasonic and satellite navigation equipment, and by integrating sensing, transmission, control, and operation, different types of actuators can be innovatively designed and developed to drive the advance of agricultural robots, to meet the delicate and complex requirements of agricultural products as operational objects, such that better productivity and standardization of agriculture can be achieved. In summary, agricultural production is developing toward a data-driven, standardized, and unmanned approach, with smart agriculture supported by actuator-driven-based agricultural robots. This paper concludes with a summary of the main existing technologies and challenges in the development of actuators for applications in agricultural robots, and the outlook regarding the primary development directions of agricultural robots in the near future

Robot Composite Learning and the Nunchaku Flipping Challenge

Advanced motor skills are essential for robots to physically coexist with humans. Much research on robot dynamics and control has achieved success on hyper robot motor capabilities, but mostly through heavily case-specific engineering. Meanwhile, in terms of robot acquiring skills in a ubiquitous manner, robot learning from human demonstration (LfD) has achieved great progress, but still has limitations handling dynamic skills and compound actions. In this paper, we present a composite learning scheme which goes beyond LfD and integrates robot learning from human definition, demonstration, and evaluation. The method tackles advanced motor skills that require dynamic time-critical maneuver, complex contact control, and handling partly soft partly rigid objects. We also introduce the "nunchaku flipping challenge", an extreme test that puts hard requirements to all these three aspects. Continued from our previous presentations, this paper introduces the latest update of the composite learning scheme and the physical success of the nunchaku flipping challenge

NASA Center for Intelligent Robotic Systems for Space Exploration

NASA's program for the civilian exploration of space is a challenge to scientists and engineers to help maintain and further develop the United States' position of leadership in a focused sphere of space activity. Such an ambitious plan requires the contribution and further development of many scientific and technological fields. One research area essential for the success of these space exploration programs is Intelligent Robotic Systems. These systems represent a class of autonomous and semi-autonomous machines that can perform human-like functions with or without human interaction. They are fundamental for activities too hazardous for humans or too distant or complex for remote telemanipulation. To meet this challenge, Rensselaer Polytechnic Institute (RPI) has established an Engineering Research Center for Intelligent Robotic Systems for Space Exploration (CIRSSE). The Center was created with a five year $5.5 million grant from NASA submitted by a team of the Robotics and Automation Laboratories. The Robotics and Automation Laboratories of RPI are the result of the merger of the Robotics and Automation Laboratory of the Department of Electrical, Computer, and Systems Engineering (ECSE) and the Research Laboratory for Kinematics and Robotic Mechanisms of the Department of Mechanical Engineering, Aeronautical Engineering, and Mechanics (ME,AE,&M), in 1987. This report is an examination of the activities that are centered at CIRSSE

Grasping With Mechanical Intelligence

Many robotic hands have been designed and a number have been built. Because of the difficulty of controlling and using complex hands, which usually have nine or more degrees of freedom, the simple one- or two-degree-of-freedom gripper is still the most common robotic end effector. This thesis presents a new category of device: a medium-complexity end effector. With three to five degrees of freedom, such a tool is much easier to control and use, as well as more economical, compact and lightweight than complex hands. In order to increase the versatility, it was necessary to identify grasping primitives and to implement them in the mechanism. In addition, power and enveloping grasps are stressed over fingertip and precision grasps. The design is based upon analysis of object apprehension types, requisite characteristics for active sensing, and a determination of necessary environmental interactions. Contained in this thesis are the general concepts necessary to the design of a medium-complexity end effector, an analysis of typica.1 performance, and a computer simulation of a grasp planning algorithm specific to this type of mechanism. Finally, some details concerning the UPenn Hand - a tool designed for the research laboratory - are presented

NASA space station automation: AI-based technology review

Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures

Shadows, touch and digital puppeteering: a media archaeological approach

Aims The practical aim of this research project is to create a multi-touch digital puppetry system that simulates shadow theatre environments and translates gestural acts of touch into live and expressive control of virtual shadow figures. The research is focussed on the qualities of movement achievable through the haptics of single and multi-touch control of the digital puppets in the simulation. An associated aim is to create a collaborative environment where multiple performers can control dynamic animation and scenography, and create novel visualisations and narratives. The conceptual aim is to link traditional and new forms of puppetry seeking cultural significance in the ‘remediation’ of old forms that avail themselves of new haptic resources and collaborative interfaces. The thesis evaluates related prior art where traditional worlds of shadow performance meet new media, digital projection and 3D simulation, in order to investigate how changing technical contexts transform the potential of shadows as an expressive medium. Methodology The thesis uses cultural analysis of relevant documentary material to contextualise the practical work by relating the media archaeology of 2D puppetry—shadows, shadowgraphs and silhouettes—to landmark work in real-time computer graphics and performance animation. The survey considers the work of puppeteers, animators, computer graphics specialists and media artists. Through practice and an experimental approach to critical digital creativity, the study provides practical evidence of multiple iterations of controllable physics-based animation delivering expressive puppet motion through touch and multiuser interaction. Video sequences of puppet movement and written observational analysis document the intangible aspects of animation in performance. Through re-animation of archival shadow puppets, the study presents an emerging artistic media archaeological method. The major element of this method has been the restoration of a collection of Turkish Karagöz Shadow puppets from the Institut International de la Marionnette (Charleville, France) into a playable digital form. Results The thesis presents a developing creative and analytical framework for digital shadow puppetry. It proposes a media archaeological method for working creatively with puppet archives that unlock the kinetic and expressive potential of restored figures. The interaction design introduces novel approaches to puppetry control systems—using spring networks—with objects under physics-simulation that demonstrate emergent expressive qualities. The system facilitates a dance of agency¹ between puppeteer and digital instrument. The practical elements have produced several software iterations and a tool-kit for generating elegant, nuanced multi-touch shadow puppetry. The study presents accidental discoveries—serendipitous benefits of open-ended practical exploration. For instance: the extensible nature of the control system means novel input—other than touch—can provide exciting potential for accessible user interaction, e.g. with gaze duration and eye direction. The study also identifies limitations including the rate of software change and obsolescence, the scope of physics-based animation and failures of simulation. Originality/value The work has historical value in that it documents and begins a media archaeology of digital puppetry, an animated phenomenon of increasing academic and commercial interest. The work is of artistic value providing an interactive approach to making digital performance from archival material in the domain of shadow theatre. The work contributes to the electronic heritage of existing puppetry collections. The study establishes a survey of digital puppetry, setting a research agenda for future studies. Work may proceed to digitise, rig and create collaborative and web-mediated touch-based motion control systems for 2D and 3D puppets. The present study thus provides a solid platform to restore past performances and create new work from old, near forgotten-forms. ¹ Following Andrew Pickering, puppetry is ‘a temporally extended back-and-forth dance of human and non-human agency in which activity and passivity on both sides are reciprocally intertwined’ PICKERING, A. 2010. Material Culture and the Dance of Agency. In: BEAUDRY, M. C. & HICKS, D. (eds.) Oxford Handbook of Material Culture Studies. Oxford University Press.