Current Issue : October - December Volume : 2017 Issue Number : 4 Articles : 5 Articles
This paper reports on the development of compact surface plasmon resonance (SPR) sensors for mobile robot olfaction.Underwater\nrobots benefit from olfactory sensing capabilities in various tasks including the search for unexploded ordnance and undersea\nwreckage. Although the SPR-based chemical sensor is a promising sensing platform, the cumbersome optical setup has been\nlimiting its use on mobile robots. The proposed sensor employs a periodic metal structure formed on a self-assembled layer of\npolystyrene particles of 200 nm in diameter.With the grating of this size, SPR can be excited even with a simple LED light source.\nThe change in the absorbance is simply measured using a photodiode. Demonstration of the proposed SPR sensor is provided by\nmounting the sensors on an underwater crayfish robot that autonomously searches for a chemical source. The fabricated sensor\nshows linear response to ascorbic acid for a concentration range from 20 to 80 mM. Responses of the bare and thiol-coated gold\nnanostructure to different chemical substances are presented to show the change in the selectivity of the sensor by the coating.\nDiscussions are made on the importance of sample collection for the sensor to attain sensitive chemical detection on a mobile\nrobot....
Mobile robots undergo a collision-free autonomous motion by using the information obtained from a suitable combination of\nmultiple sensors of same or different families. These sensors are often configured around the chassis of the robotic platform.\nHowever, little to no information is available as to how these sensors are configured on mobile robotic platforms and how many\nof these sensors to place on such platforms. Instead, an empirical approach is adopted. That is, the number of sensors of the same\nfamily or any type as well as combination of sensors for detecting obstacles is determined by experiment or information obtained\nfrom external sensors. This approach is often seen to be iterative and time consuming. In this paper, an approach for determining\nthe minimum number of sensors and their spacing on the robotic platformis proposed so that mobile robots undergo collision-free\nmotion.The effectiveness of the developed approach is experimentally tested by examining the obstacle avoidance capability of the\ntriomnidirectional wheeled robotic platform based on a motion triggering signal obtained from a skirt of ultrasonic sensors only.\nIt was observed that the newly developed approach allows this robotic platform to avoid obstacles effectively....
This paper introduces a novel gearââ?¬â??clutch mechanism that takes advantage of the difference between the directions\nin the reaction forces that occur during meshing and jamming to ensure jam-free engagement of the gears. The\nproposed mechanism is a more compact advancement of the previously developed linear rack-tilting clutch used\nto provide a step change in the reduction ratio. Mathematical models of the jam-free and stable meshing condition\nof the proposed mechanism are developed and experimentally verified, along with a discussion and recommendations\nto be considered as design guidelines. Additionally, a singularly actuated robotic joint prototype is developed\nto examine the performance of the proposed clutch mechanism. The joint was driven by a small 2-W DC motor. The\nmaximum output torque was 4 Nm with a maximum travel range of over 200ââ??¦ during the high-force phase, and\nthe maximum speed was 252ââ??¦/s with an infinite travel range during the high-speed phase. The mechanism exhibits\npotential for applications that benefit from a step transmission and long force-exerting travel range such as vices,\ngrippers, and industrial punching and shearing machines, as well as robotic arms and power assist exoskeletons....
Background: It is known that the work efficiency of teleoperated construction machinery is lower than that of\ndirectly operated machinery. Assistance via automatic control is expected to improve the work efficiency. However,\nthis assistance might break the feeling of control and prohibit control adjustments by the operator.\nMethods: We propose a semiautomatic system that fuses manual and automatic operation while maintaining\nthe same feeling of control as manual operation. The assistance approach to the working trajectory is based on the\nassumption of the existence of an ideal trajectory for the hoist swing that is a major component of an excavator. We\nevaluate the feeling of control using a sense of agency.\nResults: The results of an examination using a miniature excavator show that the assistance improved the perspective\nerror from manual with a high sense of agency.\nConclusions: Therefore proposed assistance was effective during teleoperation without a sense of perspective...
Swarm robotics has experienced a rapid expansion in recent years, primarily fueled by\nspecialized multi-robot systems developed to achieve dedicated collective actions. These\nspecialized platforms are, in general, designed with swarming considerations at the front\nand center. Key hardware and software elements required for swarming are often deeply\nembedded and integrated with the particular system. However, given the noticeable\nincrease in the number of low-cost mobile robots readily available, practitioners and\nhobbyists may start considering to assemble full-fledged swarms by minimally retrofitting\nsuch mobile platforms with a swarm-enabling technology. Here, we report one possible\nembodiment of such a technologyââ?¬â?an integrated combination of hardware and softwareââ?¬â?\ndesigned to enable the assembly and the study of swarming in a range of general-\npurpose robotic systems. This is achieved by combining a modular and transferable\nsoftware toolbox with a hardware suite composed of a collection of low-cost and off-theshelf\ncomponents. The developed technology can be ported to a relatively vast range of\nrobotic platformsââ?¬â?such as land and surface vehiclesââ?¬â?with minimal changes and high\nlevels of scalability. This swarm-enabling technology has successfully been implemented\non two distinct distributed multi-robot systems, a swarm of mobile marine buoys and a\nteam of commercial terrestrial robots. We have tested the effectiveness of both of these\ndistributed robotic systems in performing collective exploration and search scenarios,\nas well as other classical cooperative behaviors. Experimental results on different swarm\nbehaviors are reported for the two platforms in uncontrolled environments and without\nany supporting infrastructure. The design of the associated software library allows for a\nseamless switch to other cooperative behaviorsââ?¬â?e.g., leaderââ?¬â??follower heading consensus\nand collision avoidance, and also offers the possibility to simulate newly designed\ncollective behaviors prior to their implementation onto the platforms. This feature greatly\nfacilitates behavior-based design, i.e., the design of new swarming behaviors, with the\npossibility to simulate them prior to physically test them....
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