Showing papers by "V. Jagadeesh Kumar published in 2011"

A multiple loop vehicle detection system for heterogeneous and lane-less traffic

Abstract: This paper presents a novel inductive loop sensor which detects large (e.g., bus) as well as small (e.g., bicycle) vehicles and help a traffic control management system in optimizing the best use of existing roads. To accomplish the sensing of large as well as a small vehicle, a multiple loop inductive sensor system is proposed. The proposed sensor structure not only senses and segregates the vehicle type as bicycle or motor cycle or car or bus but also enables accurate counting of the number of vehicles that too in a mixed traffic flow condition. A prototype of the multiple loop sensing system has been developed using a virtual instrumentation scheme and tested. Field tests indicate that the prototype successfully detected all types of vehicles and counted, correctly, the number of each type of vehicles. Thus the suitability of the proposed multi loop sensor system for any type of traffic has been established.

A Novel Measurement Method to Determine the $C$ – $V$ Characteristic of a Solar Photovoltaic Cell

Abstract: A novel method for characterizing a single crystalline or poly-silicon solar photovoltaic (SPV) cell is proposed. The extraction of the parameters of an SPV cell is hindered by the presence of its leakage resistance. It is demonstrated here that in employing a negative resistance, not only the C-V characteristics but also the R-V characteristics along with the built-in potential and the doping concentration of an SPV cell are easily ascertained. The experimental results presented herein validate the proffered method.

Sunlight based I-V characterization of solar PV cells

Abstract: A family of current as a function of voltage (I-V) curves under different illumination conditions as specified in standards are needed to characterize a photovoltaic (PV) cell. Instead of using an artificial light as the source, a method of using sun light through fiber optic cables is described to obtain the I-V characteristics of a PV cell. Moreover, an electronic load realized with a MOSFET as a variable resistor, in conjunction with microcontroller based instrumentation automates the testing process. A prototype I-V curve tracer, developed and tested, establish the efficacy of the proposed method.

Non-invasive estimation of arterial compliance

Abstract: The evaluation of arterial compliance is very important in cardiovascular screening of “at-risk” patients. Existing techniques for local arterial stiffness estimation put a premium on technology and operator expertise. Regional stiffness, measured in terms of the pulse wave velocity, is prone to errors in both path-length and delay estimation. Here, we present a Virtual Instrument (VI) for automated estimation of both local and regional arterial compliance measures. Local arterial compliance is evaluated by utilizing an ultrasound transducer to measure the distension and lumen diameter of the carotid artery. The regional stiffness is estimated from the pulse wave velocity, measured using two magnetic transducers in a dual-channel arrangement. The automated measurement algorithms are thoroughly analyzed, to identify and minimize possible error sources as well as to optimize the design of both the transducer and the virtual instrument. The results of a few human trials are also presented to illustrate the capability of the VI to measure arterial compliance in-vivo.

A digital instrument for venous muscle pump test

Abstract: Design and development of a prototype unit to measure venous refilling time (VRT) and muscle pump capacity (MPC) during a venous muscle pump test (VMPT) is presented here. Instead of normalizing the photo-plethysmo-graph (PPG), as is common in the VMPT instruments in vogue, a suitable signal processing technique that extracts a signal proportional only to the blood volume changes underneath the PPG sensor is employed. Apart from the measurement of VRT and MPC, the prototype unit also provides a measure on the pulse rate.

A capacitive array sensing based training system for ophthalmic anesthesia

Abstract: To administer regional block (local anesthesia) prior to an eye surgery, the anesthetist must insert the needle at the correct position and angle to avoid unnecessary injury to the eye. A training module wherein an anesthetist can be trained to properly administer anesthesia would avoid the risks involved in real life training. Such a training system, where the position and angle of insertion of the needle used to administer anesthesia are determined employing a capacitive sensor array with suitable signal conditioning and sensing logic is described in this paper. Simulation studies and test results on a prototype built and tested demonstrated the practicality of the proposed scheme. The proposed scheme is designed such that the sensing system can be installed easily into a commercially available mannequin and the mannequin used for training, thus dispensing with the need for custom fabrication.

Virtual instrument to measure the magnetic properties of annealed components

Abstract: This paper presents a new technique based on comparison method of testing to distinguish an annealed magnetic sample from a non-annealed sample of same dimensions. In order to perform this test, a suitable magnetic fixture that can accommodate test samples of various inner and outer diameters has been developed and described in the paper. The paper also gives details of a virtual instrument that has been developed to perform the comparison method of testing for the annealed samples. Using the developed instrument, the samples can be tested after the manufacturing process without any further machining. The performance of the developed instrument has been verified by conducting measurements on different samples of known magnetic properties. The instrument developed distinguished the annealed samples from the non-annealed samples accurately.