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Author

Asokan Thondiyath

Other affiliations: Intuitive Surgical
Bio: Asokan Thondiyath is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Robot & Control theory. The author has an hindex of 9, co-authored 70 publications receiving 226 citations. Previous affiliations of Asokan Thondiyath include Intuitive Surgical.


Papers
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Patent
22 Jun 2011
TL;DR: In this paper, a four-jawed combinational scissor-grasper surgical tool for use in laparoscopy is described. But this tool is not suitable for use with a human operator.
Abstract: Disclosed is a four-jawed combinational scissor-grasper surgical tool for use in laparoscopy. Cutting and grasping functionalities are respectively enabled via movement of a pair of such specially contoured jaw members sliding against or splaying apart from the other pair. Also disclosed are means for achieving selectable interlocking of jaw members and mechanical linkage for their actuation by human user.

19 citations

Proceedings ArticleDOI
18 May 2015
TL;DR: A new configuration of underwater robotic vehicle, named AQUAD, is presented, a configuration with four thrusters in a plane which is inspired from an aerial quadrotor system, mathematically modelled using Newton-Euler approach.
Abstract: A new configuration of underwater robotic vehicle, named AQUAD, is presented here. It is a configuration with four thrusters in a plane which is inspired from an aerial quadrotor system. The system is designed considering the hydrodynamic challenges, and mathematically modelled using Newton-Euler approach. A PID controller is used to control the attitude of the system and implemented with the model to analyze its behavior. The system is commanded with various inputs and the performance of the model with the controller is studied. A prototype of AQUAD is being developed and the system is to be tested in real time.

18 citations

Book ChapterDOI
28 Nov 2012
TL;DR: In this article, a multi-point potential field (MPPF) method for obstacle avoidance of AUVs in a 2D dynamic environment is presented, where an arc of predefined radius on a semicircle in the positive x-axis around the bow of an AUV is discretized into equiangular points with center as the current position.
Abstract: This paper presents a multi-point potential field (MPPF) method for obstacle avoidance of Autonomous Underwater Vehicles (AUV) in a 2D dynamic environment. In this method, an arc of predefined radius on a semicircle in the positive x-axis around the bow of an AUV is discretized into equiangular points with centre as the current position. By determining the point at which the minimum potential exists, the vehicle can be moved towards that point in 2D space. Here the analytical gradient of the total potential function is not calculated as it is not essentially required for moving the vehicle to the next position. The proposed obstacle avoidance algorithm is interfaced with the dynamic model of an underactuated flat-fish type AUV. The obstacle avoidance algorithm generates the path elements to the trajectory planner and the vehicle tracks the trajectory. The details of the algorithm and simulation results are presented.

17 citations

Journal ArticleDOI
TL;DR: This paper presents the design, analysis, and testing of a novel multimodal grasper having the capabilities of shape conformation, within-hand manipulation, and a built-in compact mechanism to vary the forces at the contact surface.
Abstract: This paper presents the design, analysis, and testing of a novel multimodal grasper having the capabilities of shape conformation, within-hand manipulation, and a built-in compact mechanism to vary the forces at the contact surface. The proposed grasper has two important qualities: versatility and less complexity. The former refers to the ability to grasp a range of objects having different geometrical shape, size, and payload and perform in-hand manipulations such as rolling and sliding, and the latter refers to the uncomplicated design, and ease of planning and control strategies. Increasing the number of functions performed by the grasper to adapt to a variety of tasks in structured and unstructured environments without increasing the mechanical complexity is the main interest of this research. The proposed grasper consists of two hybrid jaws having a rigid inner structure encompassed by a flexible, active gripping surface. The flexibility of the active surface has been exploited to achieve shape conformation, and the same has been utilized with a compact mechanism, introduced in the jaws, to vary the contact forces while grasping and manipulating an object. Simple and scalable structure, compactness, low cost, and simple control scheme are the main features of the proposed design. Detailed kinematic and static analysis are presented to show the capability of the grasper to adjust and estimate the contact forces without using a force sensor. Experiments are conducted on the fabricated prototype to validate the different modes of operation and to evaluate the advantages of the proposed concept.

17 citations


Cited by
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Posted Content
TL;DR: Deming's theory of management based on the 14 Points for Management is described in Out of the Crisis, originally published in 1982 as mentioned in this paper, where he explains the principles of management transformation and how to apply them.
Abstract: According to W. Edwards Deming, American companies require nothing less than a transformation of management style and of governmental relations with industry. In Out of the Crisis, originally published in 1982, Deming offers a theory of management based on his famous 14 Points for Management. Management's failure to plan for the future, he claims, brings about loss of market, which brings about loss of jobs. Management must be judged not only by the quarterly dividend, but by innovative plans to stay in business, protect investment, ensure future dividends, and provide more jobs through improved product and service. In simple, direct language, he explains the principles of management transformation and how to apply them.

9,241 citations

01 Jan 2016
TL;DR: In this paper, the authors describe how to download and install guidance and control of ocean vehicles in the house, workplace, or perhaps in your method can be all best place within net connections.
Abstract: By searching the title, publisher, or authors of guide you in reality want, you can discover them rapidly. In the house, workplace, or perhaps in your method can be all best place within net connections. If you objective to download and install the guidance and control of ocean vehicles, it is utterly easy then, past currently we extend the colleague to buy and make bargains to download and install guidance and control of ocean vehicles therefore simple!

611 citations

Patent
31 Mar 2015
TL;DR: In this paper, a surgical tool with an elongated shaft having a proximal end and distal end is described, where an effector body includes a plurality of motor interfaces for driving the plurality of effector mechanisms.
Abstract: A surgical tool having an elongated shaft having a proximal end and distal end. A surgical end effector is located about the distal end. The surgical end effector has a plurality of effector mechanisms comprising a plurality of degree of freedoms. An effector body is located at the proximal end. The effector body includes a plurality of motor interfaces for driving the plurality of effector mechanisms. A transmission is coupled to the effector body

446 citations

Journal ArticleDOI
01 Apr 2019
TL;DR: This work proposes a novel, simpler, yet effective morphing design for quadrotors consisting of a frame with four independently rotating arms that fold around the main frame and demonstrates the first work showing stable flight without requiring any symmetry of the morphology.
Abstract: The recent advances in state estimation, perception, and navigation algorithms have significantly contributed to the ubiquitous use of quadrotors for inspection, mapping, and aerial imaging. To further increase the versatility of quadrotors, recent works investigated the use of an adaptive morphology, which consists of modifying the shape of the vehicle during flight to suit a specific task or environment. However, these works either increase the complexity of the platform or decrease its controllability. In this letter, we propose a novel, simpler, yet effective morphing design for quadrotors consisting of a frame with four independently rotating arms that fold around the main frame. To guarantee stable flight at all times, we exploit an optimal control strategy that adapts on the fly to the drone morphology. We demonstrate the versatility of the proposed adaptive morphology in different tasks, such as negotiation of narrow gaps, close inspection of vertical surfaces, and object grasping and transportation. The experiments are performed on an actual, fully autonomous quadrotor relying solely on onboard visual-inertial sensors and compute. No external motion tracking systems and computers are used. This is the first work showing stable flight without requiring any symmetry of the morphology.

205 citations

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