scispace - formally typeset
Search or ask a question
Author

Aditi Raj

Bio: Aditi Raj is an academic researcher from Indian Institute of Technology Patna. The author has contributed to research in topics: Robot & Trajectory. The author has an hindex of 3, co-authored 4 publications receiving 122 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: A detailed comparison of various design features of fish-inspired robots reported in the past decade is presented, believing that by studying the existing robots, future designers will be able to create new designs by adopting features from the successful robots.
Abstract: Underwater robot designs inspired by the behavior, physiology, and anatomy of fishes can provide enhanced maneuverability, stealth, and energy efficiency. Over the last two decades, robotics researchers have developed and reported a large variety of fish-inspired robot designs. The purpose of this review is to report different types of fish-inspired robot designs based upon their intended locomotion patterns. We present a detailed comparison of various design features like sensing, actuation, autonomy, waterproofing, and morphological structure of fish-inspired robots reported in the past decade. We believe that by studying the existing robots, future designers will be able to create new designs by adopting features from the successful robots. The review also summarizes the open research issues that need to be taken up for the further advancement of the field and also for the deployment of fish-inspired robots in practice.

183 citations

Journal ArticleDOI
TL;DR: The developed approach can impart autonomy to the Anguilliform-inspired robots that can perform autonomous inspection and maintenance of sub-sea structures having narrow regions, obstacles, and ambient flow and can be useful in various civil and defense applications.

8 citations

Journal ArticleDOI
TL;DR: Experimental results suggest that the parameters estimated using the developed approach can be useful in predicting the robot’s motion accurately.
Abstract: This paper presents an optimization-based approach to estimate the hydrodynamic parameters namely drag and added mass coefficients from free-running experiments conducted on an in-house developed Anguilliform-inspired robot. The objective of the optimization problem is to estimate the hydrodynamic parameters that minimize the differences between the trajectories obtained from the simulations and the physical experiments when operated for identical gait parameters and controller gains for both the straight and the turning motions. The hydrodynamic parameters obtained from the developed approach leads to a maximum root-mean-square (RMS) position error of 0.183 BL and a maximum RMS velocity error of 0.03 BL/s between the trajectories obtained from simulations and experiments. Experimental results suggest that the parameters estimated using the developed approach can be useful in predicting the robot’s motion accurately. Accurate robot motion prediction is the fundamental requirement for localization, collision prediction, and motion planning algorithms which in turn are required for automated inspection, maintenance, and repair of sub-sea structures using Anguilliform-inspired robots.

6 citations

Proceedings ArticleDOI
01 Oct 2016
TL;DR: An optimization based approach for determining environment parameters (added mass, added inertia and drag) from physical experiments followed by an optimization based automated parameter tuning utilizing the determined environment parameters via developed dynamics simulator is reported.
Abstract: Effectiveness of the locomotion of an Anguilliform-inspired robot depends upon the selection of various controller parameters such as amplitude, frequency, offset and low level controller gains. Manual tuning of the aforementioned parameters can be cumbersome. Automated controller parameter tuning requires repetitive experimental tests with non-optimal parameters leading to a rapid wear and tear of the robot. Use of dynamics simulator instead of a robot may alleviate this issue to some extent. However, reality gap may exist between a physical system and corresponding simulator. This paper reports an optimization based approach for determining environment parameters (added mass, added inertia and drag) from physical experiments followed by an optimization based automated parameter tuning utilizing the determined environment parameters via developed dynamics simulator. We report numerical simulations of waypoint following on different test paths using the identified environment parameters and optimized controller parameters determined using the developed approach. We found a reduction of up to 36% in travel time in our experiments. The developed approach can lead to a match between dynamics simulation and physical experiments and thereby can help in automated parameter tuning. In future, we would like to improve the performance of the optimization and to incorporate the sensing noise and environmental disturbance like current into the dynamics simulator.

4 citations


Cited by
More filters
Journal ArticleDOI
21 Mar 2018
TL;DR: This work presents the design, fabrication, control, and oceanic testing of a soft robot fish that can swim in three dimensions to continuously record the aquatic life it is following or engaging and exhibits a lifelike undulating tail motion enabled by a soft robotic actuator design.
Abstract: Closeup exploration of underwater life requires new forms of interaction, using biomimetic creatures that are capable of agile swimming maneuvers, equipped with cameras, and supported by remote human operation. Current robotic prototypes do not provide adequate platforms for studying marine life in their natural habitats. This work presents the design, fabrication, control, and oceanic testing of a soft robotic fish that can swim in three dimensions to continuously record the aquatic life it is following or engaging. Using a miniaturized acoustic communication module, a diver can direct the fish by sending commands such as speed, turning angle, and dynamic vertical diving. This work builds on previous generations of robotic fish that were restricted to one plane in shallow water and lacked remote control. Experimental results gathered from tests along coral reefs in the Pacific Ocean show that the robotic fish can successfully navigate around aquatic life at depths ranging from 0 to 18 meters. Furthermore, our robotic fish exhibits a lifelike undulating tail motion enabled by a soft robotic actuator design that can potentially facilitate a more natural integration into the ocean environment. We believe that our study advances beyond what is currently achievable using traditional thruster-based and tethered autonomous underwater vehicles, demonstrating methods that can be used in the future for studying the interactions of aquatic life and ocean dynamics.

469 citations

Journal ArticleDOI
TL;DR: A review of existing aquatic animals and AUVs is presented in this paper, where the authors compare the bio-inspired and biomimetic AUVs with animals in their locomotion.

101 citations

Journal ArticleDOI
TL;DR: Five unique soft robotic jellyfish robots were manufactured with eight pneumatic network tentacle actuators extending radially from their centers, able to freely swim untethered in the ocean, to steer from side to side, and to swim through orifices more narrow than the nominal diameter of the jellyfish.
Abstract: Five unique soft robotic jellyfish were manufactured with eight pneumatic network tentacle actuators extending radially from their centers These jellyfish robots were able to freely swim untethered in the ocean, to steer from side to side, and to swim through orifices more narrow than the nominal diameter of the jellyfish Each of the five jellyfish robots were manufactured with a different composition of body and tentacle actuator Shore hardness A three-factor study was performed with these five jellyfish robots to determine the impact that actuator material Shore hardness, actuation frequency, and tentacle stroke actuation amplitude had upon the measured thrust force It was found that all three of these factors significantly impacted mean thrust force generation, which peaked with a half-stroke actuation amplitude at a frequency of 08 Hz

96 citations

Journal ArticleDOI
TL;DR: A general review of the current status of bionic robotic fish, with particular emphasis on the hydrodynamic modeling and testing, kinematic modeling and control, learning and optimization, as well as motion coordination control.

72 citations

Journal ArticleDOI
TL;DR: Recent studies that developed 3D-printed structures not only to inform the design and application of some articulated and multi-material structures, but also to explain the mechanics of the natural biological systems they mimic are highlighted.
Abstract: 3D-printing technologies allow researchers to build simplified physical models of complex biological systems to more easily investigate their mechanics. In recent years, a number of 3D-printed structures inspired by the dermal armors of various fishes have been developed to study their multiple mechanical functionalities, including flexible protection, improved hydrodynamics, body support, or tail prehensility. Natural fish armors are generally classified according to their shape, material and structural properties as elasmoid scales, ganoid scales, placoid scales, carapace scutes, or bony plates. Each type of dermal armor forms distinct articulation patterns that facilitate different functional advantages. In this paper, we highlight recent studies that developed 3D-printed structures not only to inform the design and application of some articulated and multi-material structures, but also to explain the mechanics of the natural biological systems they mimic.

60 citations