Ashitava Ghosal

Research

Research Areas

• Bio-medical devices & Minimally invasive surgery

I have been recently interested in developing bio-medical devices. These are for minimally invasive surgeries, endoscopy and transport of organs.

We have developed a new improved laparoscopic surgical tool with a ``wrist'' like additional degree of freedom which allows a surgeon to go around obstacles, other organs, approach the surgery area with more flexibility, provide better visibility of the surgery area and enables more complex motion of the tool. More information is available here and in a tool with a cutter and a tool with a grasper .

Together with my students I have explored use of actuated flexible catheters for endoscopy. An initial paper on modeling of miniature pneumatic artificial muscles (MPAM) for actuation is available here. This work was first extended to a concept for an actuated endoscopic catheter with three MPAMs. A significantly improved model of MPAM is developed here for developing the kinematics and control of an MPAM actuated device, and a soft-robotic end-effector for independently actuating and endoscopic catheter . This work is continuing and we are also attempting to develope novel cable driven continuum robots. A representative movie demonstrating the capabilities of the MPAM actuated end-effector is shown here . This research was initially a part of a larger project on remote surgery and healthcare funded by the Robert Bosch Centre for Cyber Physical Systems at IISc Bangalore and successfully completed in 2015. The developement of minimally invasive surgery tools is continuing.

Currently we are developing several other bio-medical devices with students at CPDM . One such device called the LifeBox is being designed to be carried by a drone so that problems with common urban congestion in India and elsewhere can be overcome.

• Learning and motor control (in collaboration with Prof. Aditya Murthy, Centre for Neuroscience, IISc Bangalore)

In a recent collaborative effort with Prof. Aditya Murthy at the Centre for Neuroscience, IISc, I am exploring how we learn kinematic point-to-point reaching tasks with our arm which is know to be a redundant system. We have looked at learning under a force-field and a visuo-motor perturbation. One of the new key findings is that exploration of the redundancy in the human arm facilitates learning and has appeared in PNAS . We are now exploring learning of the dynamics of the human arm.

• Mechanisms and robots

I am interested in all kinds of mechanisms, robotic devices and computer controlled mechanical systems. I am interested in the kinematics, dynamics and control system analysis of these mechanical systems. The focus is on exploring associated theories, developement of algorithms and numerical simulation techniques, and (sometimes) hardware developement and experimental work to validate theories and numerical results. Some of my recent activities have been in analysis and design of hyper-redundant manipulators, parallel manipulators and multi-fingered hands, novel mechanisms for sun tracking for concentrated solar power plants, mobile robots for uneven terrain, adjustable mechanisms for flapping wing micro-air vehicles, and transmissions for hybrid vehicles.

Some of the recent papers in these areas:

Hyper-redundant manipulators
• Menon, S. Midhun, Ravi, V. C. and Ghosal, A., ``Trajectory planning and obstacle avoidance for hyper-redundant serial robots'', Trans. ASME, Journal of Mechanisms and Robotics, Vol. 9, pp. 041010-041010-9, 2017. PDF (7.8 Mb) Hyper-redundant robot avoiding obstacles (9.5 Mb)
• Menon,S. Midhun, Gurumoorthy, B. and Ghosal, A., ``Efficient simulation and rendering of realistic motion of one-dimensional flexible objects'', Computer-Aided Design, Vol. 75-76, pp. 13-26, 2016. PDF(336 Kb). Planar motion of a curve(98Kb) Spatial motion of a curve(1.1 Mb) Comparison of spatial motion of a curve(7.0 Mb) Comparison of spatial motion of a curve(10.9 Mb)
• Menon, S. Midhun, Ananthasuresh G. K. and Ghosal, A., ``Natural motion of one-dimensional flexible objects using minimization approaches'', Mechanism and Machine Theory, Vol. 67, pp. 64-76, 2013. PDF(3.7 Mb) Planar motion of a curve(2.1 Mb) Spatial motion of a curve(17.3 Mb)
• Ravi, V. C., Rakshit, S. and Ghosal, A., ``Redundancy Resolution using tractrix -- simulations and experiments'', Trans. ASME, Journal of Mechanisms and Robotics, Vol. 2, pp. 031013-1, 2010. PDF(1.44 Mb)
• Sreenivasan, S., Goel, P. and Ghosal, A., ``A real-time algorithm for simulation of flexible objects and hyper-reundant manipulators'', Mechanism and Machine Theory, Vol. 45, pp. 454-466, 2010. PDF(3.7 Mb) Movie-1-snake(445 Kb) Movie-2-single-hand-knot(210 Kb) Movie-3-two-hand-knot(182 Kb)
Novel Sun-tracking mechanisms
• R. B. Ashith Shyam and Ghosal, A., ``Path planning of a 3-UPU wrist parallel manipulator for sun tracking in central receiver tower systems'', Mechanism and Machine Theory, Vol. 119, pp. 130-141, 2018. PDF (1.3 Mb)
• R. B. Ashith Shyam, Acharya, M. and Ghosal, A., ``A heliostat based on a three degree-of-freedom parallel manipulator'', Solar Energy, Vol. 157, pp. 672-686, 2017. PDF (570 Kb) Az_EL and 3RPS heliostat experiments (8.5 Mb)
• Ashith Shyam R B and Ghosal, A, ``Three-degree-of-freedom parallel manipulator to track the sun for concentrated solar power systems'', Chinese Journal of Mechanical Engineering, Vol. 28, No. 4, pp. 793-800, 2015. PDF(315 Kb)
Multi-fingered hands and design of parallel manipulators
• Chaudhury, A. N. and Ghosal, A., ``Workspace of multi-fingered hands using Monte Carlo method'', Trans. ASME, Journal of Mechanisms and Robotics, Vol. 10, No. 4, pp. 041003, 2018. PDF (7.1 Mb)
• Chaudhury, A. N. and Ghosal, A., ``Optimum design of multi-degree-of-freedom closed-loop mechanisms and parallel manipulators for a prescribed workspace using Monte Carlo method'', Mechanism and Machine Theory, Vol. 118, pp. 115-138, 2017. PDF (19.5 Mb)
• Chaudhury, A. N and Ghosal, A, ``Determination of workspace volume of parallel manipulators using Monte Carlo method'', Computational Kinematics (CK 2017), Futuroscope-Poiters, France, 2017. PDF(660 Kb)
Wheeled mobile robots
• Tharakeshwar, A. and Ghosal, A, ``A mobile robot with a two-degree-of-freedom suspension for traversing uneven terrains with minimal slip: Modeling, simulation and experiments'', Mechanism and Machine Theory, Vol. 93, pp. 83-97, 2015. PDF(1.3 Mb)
• Tharakeshwar, A. and Ghosal, A., `` A three-wheeled mobile robot for traversing uneven terrain without slip: Simulation and experiments'', Mechanics based Design of Structures and Machines, Vol. 41, pp. 60-78, 2013. PDF(950 Kb)
• Tharakeshwar, A. and Ghosal, A., ``Tip over stability of a three-wheeled mobile robot capable of traversing uneven terrains without slip '', Applied Mechanics and Materials, 110-116, pp. 2940-2947, 2012. PDF(320 Kb)
• J. Auchter, C. Moore and A. Ghosal, ``Modeling of wheeled mobile robots using dextrous manipulation kinematics'', Proc. of WCECS 2007. PDF(1.0 Mb). Also available in Lecture Notes in Electrical Engineering: Advances in Computational Algorithms and Data Analysis, Springer, Full Text PDF(2.4 Mb).
• N. Chakraborty and A. Ghosal, ``Dynamic modeling and simulation of a wheeled mobile robot for traversing uneven terrain without slip'', Trans. ASME, Journal of Mechanical Design, Vol. 127, pp. 901-909, 2005. PDF(480 Kb)
• N. Chakraborty and A. Ghosal, ``Kinematics of wheeled mobile robots on uneven terrain'', Mechanism and Machine Theory, Vol. 39, pp. 1273-1287, 2004. PDF(340 Kb)
Adjustable four-link mechanisms
• Chankekar, P. V., Fenelon, M. A. A. and Ghosal, A., ``Synthesis of adjustable spherical four-link mechanisms for approximate multi-path generation'', Mechanism and Machine Theory, Vol. 70, pp. 538-552, 2013. PDF(7.8 Mb) Flapping wing MAV with two tip trajectories(18.6 Mb)
• Chankekar, P. V. and Ghosal, A., ``Optimal synthesis of adjustable planar four-bar crank-rocker type mechanism for approximate multi-path generation'', Mechanism and Machine Theory, Vol. 69, pp. 263-277, 2013. PDF(544 Kb)
Stewart platform based force-torque sensors
• Shivanand Bhavikatti, R. Ranganath, and Ghosal, A., ``A near-singular, flexure jointed, moment sensitive Stewart platform based force-torque sensor'', Proceedings of NaCoMM 2007, 2007. PDF(845 Kb)
• Ranganath, R., Nair, P. S., Mruthyunjaya, T. S., and Ghosal, A., ``A force-torque sensor based on a Stewart platform in a near singular configuration'', Mechanism and Machine Theory, Vol. 39, pp. 971-998, 2004. PDF(1.04 Mb)

• Dynamics and non-linear dynamical systems

  I have been interested in non-linear dynamics, chaos and related areas on and off. I and my students have done extensive numerical simulations of ODE's which are used to model feedback controlled(model based and PID) robots. The main result is that when the controller gains are "low'', the ODE's typically used to model feedback controlled robot can exhibit chaos, and hence ``robustness issues'' of robot control laws need to be re-looked into. We have also demonstrated that a rotating flexible link (model for a wind turbine blade) can exhibit chaos for certain geometries and forcing.

  Some of the papers in this area:

• Sandeep Reddy, B. and Ghosal, A., ``Robustness analysis of simple and augmented proportional plus derivative controller in trajectory following robots using Floquet theory'', Trans. ASME, Journal of Computational and Nonlinear Dynamics, Vol. 13, pp. 074501-1, 2018. PDF (1.7 Mb)
• Sandeep Reddy, B. and Ghosal, A., ``Chaotic motion in a flexible beam and synchronization'', Trans. ASME, Journal of Computational and Nonlinear Dynamics, Vol. 12(4), pp. 0445055-044505-7, 2017. PDF (3.7 Mb)
• Sandeep Reddy, B. and Ghosal, A., ``Asymptotic stability and chotic motions in trajectory following feedback controlled robots'', Trans. ASME, Journal of Computational and Nonlinear Dynamics, Vol. 11(5), pp. 051012-051012-11, 2016. PDF(2.9 Mb)
• Sandeep Reddy, B. and Ghosal, A, ``Nonlinear dynamics of a rotating flexible link'', Trans. ASME, Journal of Computational and Nonlinear Dynamics, Vol. 10(6), pp. 061015-061015-9, 2015. PDF(8.3 Mb)
• Ravishankar, A. S., and Ghosal, A., ``Nonlinear dynamics and chaotic motions in feedback controlled two and three-degree-of-freedom robots'', International Journal of Robotics Research, Vol. 18, No. 1, 1999, pp. 93-108. PDF(575 Kb)
• Shrinivas, L. and Ghosal, A., ``Chaos in robot control equations'', Int. Journal of Bifurcation and Chaos, Vol. 7, No.3, 1997, pp. 707-720. PDF(1.4 Mb - scanned orginal)
• Shrinivas, L. and Ghosal, A., ``Possible chaotic motions in a feedback controlled 2R robot'', Proc. of IEEE Conf. on Robotics and Automation, April 1996, Minneapolis. PDF(521 Kb - scanned original)

I have also done a bit or work on developing dynamics algorithms for large rigid multi-body systems.

• Sangamesh Deepak R. and Ghosal, A., ``Special coordinates associated with recursive forward dynamics algorithm for open loop rigid multi-body system'', Trans. of ASME, Journal of Applied Mechanics, Vol. 75 (5), pp. 051003-11, 2008. PDF(392 Kb)

I did some work on flexible manipulators and structures in the past and I continue to work on them. Some of the recent papers in these areas are:

• Kamesh, D., Pandiyan, R. and Ghosal, A., ``Passive vibration isolation of reaction wheel disturbances using a low frequency flexible space platform'', Journal of Sound and Vibration, Vol. 331, pp. 1310-1330, 2012. PDF(760 Kb)
• Kamesh, D., Pandiyan, R. and Ghosal, A., ``Modelling, design and analysis of a low frequency platform for attenuating micro-vibrations in spacecraft'', Journal of Sound and Vibration, Vol. 329, pp. 3431-3450, 2010. PDF(1.30 Mb)
• S. Shankar Narayan, P. S. Nair and Ghosal, A., ``Dynamic interaction of rotating momentum wheels with spacecraft elements '', Journal of Sound and Vibration, Vol. 315, pp. 970-984, 2008. PDF(1.54 Mb)
• M. Chandra Shaker and Ghosal, A., ``Nonlinear modeling of flexible manipulators using non-dimensional variables'', Trans. ASME, Journal of Nonlinear and Computational Dynamics, Vol. 1, pp. 123-134, 2006. PDF(1.55 Mb)
• Theodore, R. J., Ghosal, A., ``Robust control of multilink flexible manipulators'', Mechanism and Machine Theory, Vol. 38, No. 4, pp. 367-377, 2003. PDF(232 Kb)

Some older papers on flexible manipulators:

• Reddy, B. S., Simha, K. R. Y., and Ghosal, A., ``Free vibration of kinked cantilever with attached masses'', Journal of the Acoustical Society of America, Vol. 105, No. 1, pp. 164-174, 1999. PDF(241 Kb)
• Nagaraj, B. P., Nataraju, B. S. and Ghosal, A., ``Dynamics of a two-link flexible system undergoing locking-- mathematical modeling and comparison with experiments'', Journal of Sound and Vibration, Vol. 207, No. 4, 1997, pp. 567-589.
• Theodore, R. J., Ghosal, A., ``Modeling of flexible manipulators with prismatic joints'', IEEE Trans. on Systems, Man and Cybernetics -- Part B, Vol. 27, No. 2, April 1997, pp. 296-305. PDF(402 Kb)
• Theodore, R. J., Ghosal, A., `` Comparison of the assumed modes and finite element models for flexible multi-link manipulators'', Int. Journal of Robotics Research, Vol. 14, No. 2, April 1995, pp. 91-111. PDF(382 Kb)
• Theoretical kinematics and mechanisms

My theses (M. S. and Ph. D) in theoretical kinematics and mechanisms and I continue to work in this and related areas. Some of the recent papers in this area are:

• Srivatsan, R. Arun, Bandyopadhyay, S. and Ghosal, A., ``Analysis of the degrees-of-freedom of spatial parallel manipulators in regular and singular configurations'', Mechanism and Machine Theory, Vol. 69, pp. 127-141, 2013. PDF(12.5 Mb)
• Bandyopadhyay, S. and Ghosal, A., ``An eigenproblem approach to classical screw theory'', Mechanism and Machine Theory, Vol. 44, pp. 822-834, 2009. PDF(204Kb)
• Bandyopadhyay, S. and Ghosal, A., ``An algebraic formulation of static isotropy and design of statically isotropic 6-6 Stewart platform manipulators'', Mechanism and Machine Theory, Vol. 44, pp. 1360-1370, 2009. PDF(460 Kb)
• Bandyopadhyay, S. and Ghosal, A., ``An algebraic formulation of kinematic isotropy and design of isotropic 6-6 Stewart platform manipulator'', Mechanism and Machine Theory, Vol. 43, pp. 591-616, 2008. PDF(2.33 Mb)
• Sangamesh Deepak R. and Ghosal, A., ``A note on the diagonalizability and the Jordan form of the 4 x 4 homogeneous transformation matrix'', Trans. of ASME, Journal of Mechanical Design, Vol. 128, pp. 1343-1348, 2006. PDF(240 Kb)
• Bandyopadhyay, S. and Ghosal, A., ``Geometric characterization and parametric representation of the singularity manifold of a 6-6 Stewart platform manipulator'', Mechanism and Machine Theory, Vol. 41, pp. 1377-1400, 2006. PDF(2.24Mb)
• Bandyopadhyay, S. and Ghosal, A., ``Anaytical determination of principal twists in serial, parallel and hybrid manipulators using dual vectors and matrices'', Mechanism and Machine Theory, Vol. 39, pp. 1289-1305, 2004. PDF(275 Kb)
• Bandyopadhyay, S. and Ghosal,  A., ``Analysis of configuration space singularities of closed-loop mechanisms and parallel manipulators'', Mechanism and Machine Theory, Vol. 39, pp. 519-544, 2004. PDF(382 Kb)

Some older papers on theoretical kinematics and mechanisms:

• Bandyopadhyay, S., Ghosal, A., and Ravani, B., ``A differential geometric method for kinematic analysis of two- and three-degree-of-freedom rigid body motions'', Mechanics Based Design of Structures and Machines, Vol. 30, No. 3, pp. 279-307, 2002. PDF(610 Kb)
• Ghosal, A., and Ravani, B., ``Differential geometric analysis of singularities of point trajectories of serial and parallel manipulators'', ASME Trans., Journal of Mechanical Design, Vol. 123, pp. 80-89, 2001. PDF(671 Kb)
• Chowdhury, P., and Ghosal A., ``Singularity and controllability analysis of parallel manipulators and closed-loop mechanisms'', Mechanism and Machine Theory, Vol. 35, pp. 1455-1479, 2000. PDF(525 Kb)
• Ghosal, A., and Ravani, B., ``A dual ellipse is a cylindroid'', ASME Mechanisms Conference, Atlanta, USA, September 1998.
• Basu, D., and Ghosal, A., ``Singularity analysis of platform-type multi-loop spatial mechanisms'', Mechanism and Machine Theory, Vol. 32, No. 3, March 1997, pp. 113-127. PDF(886 Kb - scanned original)
• Ghosal, A., Roth, B., ``Instantaneous properties of multi-degrees-of-freedom motions -- Point trajectories'', Trans. ASME, Journal of Mechanisms, Transmission and Automation in Design, Vol. 109, No. 1, March 1987.
• Dwarakanath, T. A., Ghosal, A., Srinivasa, U., ``Kinematic analysis and design of articulated manipulators with joint motion constraints'', Trans. of ASME, Journal of Mechanical Design, Vol. 116, No. 3, Sept. 1994, pp. 969-972.
• Ghosal, A., Roth, B., ``A new approach for kinematic resolution of redundancy'', Intl. Journal of Robotics Research, Vol. 7, No. 2, 1988.
• Sandor, G. N., Kohli, D., Hernandez, M. Jr., Ghosal, A., ``Kinematic analysis of a three-link spatial mechanism containing sphere-plane and sphere-groove pairs'', Mechanism and Machine Theory, Vol. 19, No. 1, 1984.
• Sandor, G. N., Kohli, D., Reinholtz, C. F., Ghosal, A., ``Closed-form analytic synthesis of a five-link spatial motion generator'', Mechanisms and Machine Theory, Vol. 19, No. 1, 1984.

• Design and CAD/CAM

I am an Associate Faculty in the Centre for Product Design and Manufacture, IISc, Bangalore. As a part of this, I teach a course on Computer Aided Product Design and have guided several M. Des. Projects. Some of the products and patents arising out of the course and otherwise are:

• Ghosal, A., Goel, P., Kumbhare, H. and Ramesh, M., Laparoscopic Aparatus, Indian Patent Application No. 2110/CHE/2009. PCT Application PCT/IN2010/000559, Filing Date 25/08/2010. Details available here.
• Gupta, Aloke K, Ghosal, A., Ameen, A., Kamate, V., Mahantappa, U, and Amahantesh, D. V., Safety Cap and Sealing System for LPG Cylinder, Indian Patent Application No. 1689/MUM/2009 A. See Indian Patent Office link and here are some Pictures.
• Ghosal, A., Pal, S. and Banerjee, A., Foldable Bicycle, Indian Patent No. 207565, Grant Date 14/06/2007. See Indian Patent Office link. Pictures before folding and after folding .