Position and Heading Control of an Autonomous Underwater Vehicle using Model Predictive Control

Autonomous Underwater Vehicle (AUV) is currently being used for scientific research, commercial and military underwater applications. AUV requires autonomous guidance and control systems to perform underwater applications. This Thesis is concerned with position and heading control of AUV using Model Predictive Control. Position control is a typical motion control problem, which is concerned with the design of control laws that force a vehicle to reach and maintain a fixed position. The position control of body fixed x-axis to a fixed point using MPC toolbox of MATLAB is done here. System is modelled Using INFANTE AUV hydrodynamic parameters. There is physical limitation on thruster value. Heading control is concerned with the design of control laws that force a vehicle to reach and maintain a fixed direction. There are physical limitations on control input (Rudder deflection) in heading control also a high yaw rate can produce sway and roll motion, which makes it necessary to put constraint on yaw rate. The MPC have a clear advantage in case of control and input constraints. To avoid constraint violation and feasibility issues of MPC for AUV heading control Disturbance Compensating (DC) MPC scheme is used. The DC-MPC scheme is used for ship motion control and gave better results so we are using the proposed scheme to AUV heading control. A 2 DOF AUV model is taken with yaw rate and rudder deflection constraints. Line of sight (LOS) guidance scheme is utilised to generate the reference heading, which is to be followed. Two types of disturbances are taken constant and sinusoidal. Then simulation has been done for standard MPC, M-MPC and DC-MPC. A (DC) MPC algorithm is used to satisfy the state constraints in presence of disturbance to get a better performance. Standard MPC gives good result without disturbance. But in case of disturbance yaw constraint is violated. At many time steps the standard MPC has no solution for given yaw rate constraint at those time steps the constraints have been removed. The M-MPC satisfies the constraints. The DC-MPC gives better result in comparison to standard MPC and Modified MPC. The steady state oscillations are less in DC-MPC as compared to M-MPC for sinusoidal disturbances. The minimization of extra cost function in DC-MPC makes the result better than M-MPC. By solving the extra cost function we try to make response close to that of without disturbance. The only added complexity in DC-MPC is ni-dimensional optimization problem. Which is very less compared to Np*ni, complexity of M-MPC. Where ni is the dimension of control input and Np is value of prediction horizon. The feasibility of DC-MPC scheme largely depends on the magnitude of disturbance. If disturbance is too large then this scheme is not feasible

STUDY OF THYROID PROFILE IN GERIATRIC TYPE-2 DIABETICS IN JHARKHAND

Objective: To study the  association of the two endocrinal disorders (Diabetes mellitus and thyroid disease) in randomly selected geriatric patients.Method: The study includes 80 patients in geriatric age groups with type 2 diabetes mellitus visiting the Medicine out patients department. Thyroid profile were assayed  in type 2 diabetic patients.Results: It was noted that thyroid dysfunction was prevalent in 41(51.25%)  out of the 80 geriatric age group patients with 31(38.75%) being hypothyroidism, 7 (8.7%) having subclinical hypothyroidism and 3 (3.7%) having a hyperthyroid state.Conclusion: The study shows that screening should be strongly recommended for all type 2 diabetics to rule out thyroid dysfunction in patients with increasing age.Keywords: Thyroid profile, Geriatric patients, Diabetes mellitus.Â

“Institutional design for decentralisation needs to move away from a solely normative approach to appreciate the political” – Satyajit Singh

As governments across the globe experiment with decentralisation, Professor Satyajit Singh has written The Local in Governance: Politics, Decentralization and Environment, a book which explores this shift in India. Ahead of the publication next month, he spoke to Pankaj Kumar Jha about the existing literature on decentralisation and how he hopes his new work will impact policymaking

quTARANG: A python GPE solver to study turbulence in quantum systems

quTARANG is a Python-based general-purpose Gross-Pitaevskii Equation (GPE) solver. It can solve GPE in 1D, 2D and 3D and has the ability to run on both CPU and GPU. It has been developed to study turbulence in quantum systems, specifically in atomic Bose-Einstein condensates, and can be used to study different quantities, such as the varied spectra associated with quantum turbulence.Comment: 6 Pages, submitted to JOSS for publication, typos correcte

Engineering valley quantum interference in anisotropic van der Waals heterostructures

In this paper, we present a novel route to manipulate the spontaneous valley coherence in two-dimensional valleytronic materials interfaced with other layered materials hosting anisotropic polaritonic modes. We propose two implementations—one, using anisotropic plasmons in phosphorene and another with hyperbolic phonon polaritons in α−MoO₃. In particular, we show the electrostatic tunability of the spontaneous valley coherence achieving robust valley coherence values in the near-infrared wavelengths at room temperature. The tunability of this valley coherence shown in these heterostructures would enable the realization of active valleytronic quantum circuitry

Engineering valley quantum interference in anisotropic van der Waals heterostructures

In this paper, we present a novel route to manipulate the spontaneous valley coherence in two-dimensional valleytronic materials interfaced with other layered materials hosting anisotropic polaritonic modes. We propose two implementations—one, using anisotropic plasmons in phosphorene and another with hyperbolic phonon polaritons in α−MoO₃. In particular, we show the electrostatic tunability of the spontaneous valley coherence achieving robust valley coherence values in the near-infrared wavelengths at room temperature. The tunability of this valley coherence shown in these heterostructures would enable the realization of active valleytronic quantum circuitry

Demonstrating the asymmetry of the Indian Ocean Dipole response in regional earth system model of CORDEX-SA

An accurate representation of the Indian Ocean Dipole (IOD) is crucial for the reliable projection of Indian summer monsoon rainfall, making it necessary to improve the understanding of the response of the IOD in the warming climate. For the first time, a high-resolution regional earth system model (RESM) over the CORDEX-SA domain is used to investigate the IOD characteristics. The model performance is evaluated in simulating the IOD and associated mechanism. RESM shows a good resemblance in simulating IOD phases (positive and negative). However, the systematic discrepancy is observed in magnitude. Additionally, RESM well represented the positive IOD's inter-event variability. For example, the stronger event dominated by significant cold anomalies over Sumatra with enhanced westward-extended while a moderate event shows weak cooling confined to the region of Sumatra. Additionally, RESM shows potential to distinguish the ENSO and non-ENSO years with more remarkable skill in representing the spatial pattern of SST over IOD region during non-ESNO years than ENSO years. The RESM realistically simulated the IOD amplitude with greater skill than CMIP5/6 models reported in the earlier studies, indicating reliability towards the projection of the Indian summer monsoon. The weaker IOD-ENSO relationship is caused by producing the more significant number of IOD during non-ENSO years. Despite this reliable fidelity, IOD's slightly earlier peak is driven by the early establishment of low-level equatorial easterly wind. This study provided valuable insight into the IOD's different phases, responsible forcings, and limitations of the RESM in accounting for the role of internal climate variability that can be useful for further improvement in the model physics