COCrIP: Compliant OmniCrawler In-pipeline Robot

This paper presents a modular in-pipeline climbing robot with a novel compliant foldable OmniCrawler mechanism. The circular cross-section of the OmniCrawler module enables a holonomic motion to facilitate the alignment of the robot in the direction of bends. Additionally, the crawler mechanism provides a fair amount of traction, even on slippery surfaces. These advantages of crawler modules have been further supplemented by incorporating active compliance in the module itself which helps to negotiate sharp bends in small diameter pipes. The robot has a series of 3 such compliant foldable modules interconnected by the links via passive joints. For the desirable pipe diameter and curvature of the bends, the spring stiffness value for each passive joint is determined by formulating a constrained optimization problem using the quasi-static model of the robot. Moreover, a minimum friction coefficient value between the module-pipe surface which can be vertically climbed by the robot without slipping is estimated. The numerical simulation results have further been validated by experiments on real robot prototype

Design and optimal springs stiffness estimation of a Modular OmniCrawler in-pipe climbing Robot

This paper discusses the design of a novel compliant in-pipe climbing modular robot for small diameter pipes. The robot consists of a kinematic chain of 3 OmniCrawler modules with a link connected in between 2 adjacent modules via compliant joints. While the tank-like crawler mechanism provides good traction on low friction surfaces, its circular cross-section makes it holonomic. The holonomic motion assists it to re-align in a direction to avoid obstacles during motion as well as overcome turns with a minimal energy posture. Additionally, the modularity enables it to negotiate T-junction without motion singularity. The compliance is realized using 4 torsion springs incorporated in joints joining 3 modules with 2 links. For a desirable pipe diameter (\text{\O} 75mm), the springs' stiffness values are obtained by formulating a constraint optimization problem which has been simulated in ADAMS MSC and further validated on a real robot prototype. In order to negotiate smooth vertical bends and friction coefficient variations in pipes, the design was later modified by replacing springs with series elastic actuators (SEA) at 2 of the 4 joints.Comment: arXiv admin note: text overlap with arXiv:1704.0681

Regression Estimation of Bongaart Indices from the Childbearing Indices: A Study of India/States/Districts

In a series of research articles El-khorazaty, Horne and Suchindran have showed how one can derive for any given population indirectly various childbearing and Bongaart fertility-inhibiting indices using only given information on the ASFRs, and the mathematical and regression models suggested by them. Very recently Bongaart revised his old model and suggested a set of new revised formulae to estimate various fertility-inhibiting indices. Following El-Khorazaty and Horne it is aimed to show in the present paper how one can derive various Bongaart revised fertility-inhibiting indices from the given information on various childbearing indices which were further seen derived from the only given information on TFR and a set of regression models that were earlier suggested by the first author and it is shown that the present study succeed in giving meaningful estimates for India its States, UTs, and Districts. Various regression models referring to estimation of childbearing indices used in this study were developed earlier by Ponnapalli using the state level time series of ASFRs overtime of the SRS of India and Horne et al., mathematical model. The regression models used in indirect estimation of the fertility-inhibiting indices from the TFR and also from the childbearing indices were developed by Ponnapalli using the Bongart indices of the DHS surveys earlier given by Bongaart in his revised recent study.Keywords: Fertility; Childbearing indices; Indirect Estimation; Bongaart Indices; ASFRs; TFR; TF; Indi

Regression Estimation of Childbearing Indices from TFR: A Study of India, States, and Its Districts

In the absense of direct estimates of fertility indicators such as total fertility rate (TFR) and childbearing indices, it is customory in the field of demography/Population studies to derive the same using some suitable indirect procedure. In this paper an attempt has been made at first to introduce a new regression methodology for estimating indirectly the maternal childbearing indices from the only given information on TFR. Secondly, using the regression models provided here and using an indirect estimate of TFR of districts in India a set of childbearing indices for disricts in India are derived and they are further used in understanding the fertility transition in India by districts during the time period of 1997 to 2011. Finally, it is shown successfully in this paper by an analysis of the findings that the regression models as well as the estimates of childbearing indices of the district in India are found to be very useful in understanding the fertility transition in India during the study period of 1997 to 2011

Incorporating the Geometric Relationship of Adjacent Objects in Multi-Object Shape Analysis

Modeling the shared boundary region between adjacent 3D objects can provide useful information regarding the geometric relationship of objects when performing multi-object shape analysis. Our analysis goes about modeling the shared boundary region of 3D objects with a 2D s-rep. An s rep is able to capture shape features like width, boundary locations, boundary normals, and object curvature. A 2D s-rep is fit to the shared boundary region of adjacent objects by mapping the shared boundary region onto the medial surface of an ellipsoid. Mapping onto a flat surface allows for the creation of the 2D s-rep, which we can map back to the curved shared boundary region. Incorporating the 2D s-rep of the shared boundary region along with the 3D s-reps of the adjacent objects allows for a more detailed multi-object representation to utilize for shape analysis. We conducted an experiment with computer-generated data of pairs of deformed ellipsoids that were either stretched, bent, or shifted and analyzed how well our representation is able to classify a deformed pair of ellipsoids from an undeformed pair. Our study found that a representation that included a 2D s-rep of the shared boundary region slightly increased the classification accuracy for classifying stretched, bent, and shifted ellipsoids.Bachelor of Scienc

An approach to enhance the efficiency of the solar PV panel in partial shading condition: A Review

Hot spot heating causes permanent destruction of the solar cell structure. Areas with high impurity contaminants and high concentration of transition metals have the most number of hot spot heating. When the operating current of the overall series string approaches the short circuit current of a bad cell then the overall current becomes limited by the bad cell. The good cell becomes forward bias, which reverse biases the bad cell. This leads to large dissipation of power in the bad cell. Enormous power is dissipated in the bad cell or hot spot that results in destructive effects like glass cracking, melting of solder or degradation of a solar cell. The solar panel works best when there is no shade on them. If there is a partial shadow in any one of the arrays, the efficiency of the solar panel drops to a great extent. The shaded cell becomes reverse biased so maximum power will be dissipated on the shaded cell. The heat developed due to the reverse biased of the shaded region adds to the dissipated power

Investigation on the Effect of Cable Length on Pulse Shape of High Voltage High Pulse Power Supply

In the present scenario of pulse power applications, transmission of high voltage pulses varies as per load condition. In the early days of its application, High Voltage High Pulse Power Supply (HVHPPS) design saw short distance between load and source, where the effect of cable length was not taken into account for design. This paper presents the effect of cable length on pulse shape of High Voltage High Pulse Power Supply. The load under observation is Klystron based high energy particle accelerator system. The performance of pulse power systems were observed continuously on a daily basis throughout the year and detailed analysis was carried out. This paper generates the model of pulse forming system and provides details of pattern distortion of the pulse shape due to various dynamic parameter changes i.e. impedance, Load Voltage, Load Current, Cavity Dimensional Changes (Microwave components) due to temperature variations and performance of the power supply. The results were analysed and validated with hardware results across a range of actual industrial loads

Association of major depression with blood pressure and vascular complications of type 2 diabetes mellitus

Background: The WHO estimates the diabetic population to increase to 366 million by 2030 worldwide, with maximum 79.4 million Indians. Depression is an undiagnosed co-morbidity leading to significant disability, non-compliance and postulated to cause poorer glycemic control leading to early disease complications. We aimed to detect depression and study its correlation with vascular complications among type 2 diabetes mellitus (T2DM) patients.Methods: In an observational study, 312 randomly selected T2DM patients were evaluated at tertiary care center in Northern India. Socio-demographic, clinical and laboratory data was collected. Montgomery Asberg depression rating scale (MADRS) was used to detect depression. Groups with and without major depression were compared for various diabetes variables. Statistical analysis was carried out using the SPSS version 14.0.Results: One third T2DM patients (32.05%) suffered from major depression. Depression was significantly associated with diabetic patients having cardiac (p 0.01), ophthalmic (p 0.04), nephropathy (p 0.01), cerebrovascular (p 0.001) complications and diabetic foot (p 0.04). However, depression showed no significant association with systolic blood pressure, neuropathic and infectious complications.Conclusions: Identification of depression and its appropriate management may go a long way in delaying diabetic vascular complications by improving treatment adherence and subsequently glycemic control.