Krishan Kumar | Rajasthan Technical University (original) (raw)
Phone: +91-9351111427
Address: CSIR-CEERI, Pilani, Rajsthan-333031
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Papers by Krishan Kumar
— In this paper, a simple but efficient analog interface circuit for floating capacitive sensor i... more — In this paper, a simple but efficient analog interface circuit for floating capacitive sensor is presented. In most of the capacitive sensor, the offset and parasitic components are associated with the sensor and varies with the measurand. In these sensors, the change in the sensor capacitance due to measurand can be very small but having a relatively large offset capacitance in parallel and also the value of parasitic capacitances are not constant and varies with measurand. Hence, the error due to offset and parasitic components will propagate in the output which will degrade the performance of the sensor system. The proposed analog front end circuit accepts these types of sensors and provide an output voltage proportional to capacitance change due to measurand. A prototype board has been developed and tested for different values of of the parasitic and offset capacitance by varying the variable sensor capacitance. The circuit validate the theoretical expectation and without any visible effect on output voltage on offset and parasitic capacitance. The worst case error for all taken cases are found to be within 1%. In order to test the validity of proposed interface circuit in real time application, a capacitive humidity sensor is fabricated and tested with the proposed circuitry. The interface circuit found to be working well with humidity sensor in the range of 30 to 90% RH.
—when information exchange occurs between people via a network, then authentication and security ... more —when information exchange occurs between people via a network, then authentication and security of data have more priority. This paper introduces a low cost, handheld, wireless electronic notice board by using Atmel's ATmega32 microcontroller and different wireless technologies (Bluetooth and ZigBee) and their performance analysis based on the parameter such as range, BER (bit error rate), RSSI (Received signal strength indicator), signal attenuation and power consumption. The notice board receives serial data from wireless module receiver and displays it on the graphical liquid crystal display. We have realized a common communication receiver hardware for notice board having compatibility with both wireless modules i.e. Bluetooth and ZigBee. We used KS0108 based 128x64 graphical LCD as display element.
Abstract-This paper presents a control strategy using fuzzy logic based approach coupled with cla... more Abstract-This paper presents a control strategy using fuzzy logic based approach coupled with classical gain compensator based on pole placement for the analysis of a third order model developed for the yaw plane dynamics of an Autonomous underwater vehicle. However, the first principle based mathematical models formulated for AUV are based on variety of assumptions and uses estimated coefficients to represent the dynamics and uncertain oceanic conditions, may not be the true representation of the actual system. In order to take care of the above unknown disturbances, a fuzzy logic control scheme with state feedback gain compensator based on heuristic knowledge is utilized to compensate model parameter uncertainties. The obvious benefit of the scheme over other conventional methods lies in its simplicity and emulation of common human logic in the design process. It provides good performance objectives such as minimal overshoot, fast rise and settling time and less transient phase oscillations under variety of disturbances encountered in deep-sea environment. The controller formulated is self-adjusting and adaptive in the sense that once it is tuned and customized for a given input domain, it ensures the stable control excursion under variety of operating conditions. Its response and performance are compared with stand-alone fuzzy logic controller and classical state feedback controller designed for yaw dynamics of the system. Keywords-Autonomous Underwater Vehicle, six degrees-of freedom, yaw control,fuzzy logic controller, pole placement control design method, state-feedhack gain compensator, phase lead compensator.
— In this paper, a simple but efficient analog interface circuit for floating capacitive sensor i... more — In this paper, a simple but efficient analog interface circuit for floating capacitive sensor is presented. In most of the capacitive sensor, the offset and parasitic components are associated with the sensor and varies with the measurand. In these sensors, the change in the sensor capacitance due to measurand can be very small but having a relatively large offset capacitance in parallel and also the value of parasitic capacitances are not constant and varies with measurand. Hence, the error due to offset and parasitic components will propagate in the output which will degrade the performance of the sensor system. The proposed analog front end circuit accepts these types of sensors and provide an output voltage proportional to capacitance change due to measurand. A prototype board has been developed and tested for different values of of the parasitic and offset capacitance by varying the variable sensor capacitance. The circuit validate the theoretical expectation and without any visible effect on output voltage on offset and parasitic capacitance. The worst case error for all taken cases are found to be within 1%. In order to test the validity of proposed interface circuit in real time application, a capacitive humidity sensor is fabricated and tested with the proposed circuitry. The interface circuit found to be working well with humidity sensor in the range of 30 to 90% RH.
—when information exchange occurs between people via a network, then authentication and security ... more —when information exchange occurs between people via a network, then authentication and security of data have more priority. This paper introduces a low cost, handheld, wireless electronic notice board by using Atmel's ATmega32 microcontroller and different wireless technologies (Bluetooth and ZigBee) and their performance analysis based on the parameter such as range, BER (bit error rate), RSSI (Received signal strength indicator), signal attenuation and power consumption. The notice board receives serial data from wireless module receiver and displays it on the graphical liquid crystal display. We have realized a common communication receiver hardware for notice board having compatibility with both wireless modules i.e. Bluetooth and ZigBee. We used KS0108 based 128x64 graphical LCD as display element.
Abstract-This paper presents a control strategy using fuzzy logic based approach coupled with cla... more Abstract-This paper presents a control strategy using fuzzy logic based approach coupled with classical gain compensator based on pole placement for the analysis of a third order model developed for the yaw plane dynamics of an Autonomous underwater vehicle. However, the first principle based mathematical models formulated for AUV are based on variety of assumptions and uses estimated coefficients to represent the dynamics and uncertain oceanic conditions, may not be the true representation of the actual system. In order to take care of the above unknown disturbances, a fuzzy logic control scheme with state feedback gain compensator based on heuristic knowledge is utilized to compensate model parameter uncertainties. The obvious benefit of the scheme over other conventional methods lies in its simplicity and emulation of common human logic in the design process. It provides good performance objectives such as minimal overshoot, fast rise and settling time and less transient phase oscillations under variety of disturbances encountered in deep-sea environment. The controller formulated is self-adjusting and adaptive in the sense that once it is tuned and customized for a given input domain, it ensures the stable control excursion under variety of operating conditions. Its response and performance are compared with stand-alone fuzzy logic controller and classical state feedback controller designed for yaw dynamics of the system. Keywords-Autonomous Underwater Vehicle, six degrees-of freedom, yaw control,fuzzy logic controller, pole placement control design method, state-feedhack gain compensator, phase lead compensator.