Volume 3 Issue 1
Authors: Ahmad Banakar; Ebrahim Taghinezhad
Abstract: Diesel engines are extensively used in agricultural machineries such as water pumps and power generators. The protection and maintenance of these engines have been a major concern especially in remote areas. In this paper the relation of diesel engine temperature with fan belt and radiator water was investigated. In the normal condition, the fan and radiator control the engine temperature, so temperature increase would be limited. If, by any reason, the fan belt snaps or radiator leaks, the engine temperature will overflow the defined limit leading to weak operation. An electro-mechanical system was designed to protect diesel engine based on the critical temperature. The system constituted an electro-valve and electronic devices which were supplied by two voltages from an electronic circuit. This circuit switched the diesel engine off if the engine temperature exceeded the critical temperature.
Keywords: Diesel Engine; Radiator; Temperature Sensor
Authors: Kanthi. M; George V.I; Mruthyunjaya H.S
Abstract: Active ankle foot orthosis is used to support or restore the complex ankle foot movements of the subjects with neurological or muscular pathologies. Neurological impairments are due to stroke, polio, multiple sclerosis, spinal cord injuries, and cerebral palsy. This paper aims at designing an embedded system for active ankle foot orthosis, which can be used in the case of hemiparesis subjects as a rehabilitation aid. The designed orthosis can aid both dorsiflexion and plantar flexion movements. The ATmega328 microcontroller is used to control the position of the actuator. The microcontroller generates pulse width modulation signals according to the outputs given from the tactile sensors. The sensors are mounted inside the soles of a healthy leg and the orthotic device. During each gait cycle the microcontroller estimates the position of the foot in relation to the gait phases based on the information obtained by the tactile sensors and the adaptation of the joint torque with the help of an actuator.
Keywords: Embedded System Design; Ankle Foot Orthosis; Orthotic; Gait; Tactile Sensor; Arduino Uno; Microcontroller
Authors: Alexander A Tachkov
Abstract: This paper presents an approach to search for a fire source in a group of rooms using a mobile tracked reconnaissance robot. The approach is based on the proportional guidance method in a temperature field. This method integrates robot kinematic and dynamic equations. According to the control strategy, a robot angular velocity is proportional to the rate of turn of the temperature gradient that guides the robot to the fire. We prove that the passive proportional guidance method is equivalent to the gradient-search method. The navigation law is simulated and tested experimentally using the tracked robot in the case of a temperature field.
Keywords: Proportional Navigation; Search for Source of Fire Using Mobile Robot; Exploration of Fire
Authors: M K Alaria; Y Choyal; A K Sinha
Abstract: The design of face cooled double disc window for 42 GHz, 200 kW Gyrotron has been carried out using the CST microwave studio. In this design double discs D1 and D2 of diameter 85 mm and thickness 3.2 mm sapphire window and spacing of discs 2.7 mm have been used in the simulation and sapphire discs are face cooled by Coolant FC-75. The return loss (S11) and transmission loss (S21) of the 42 GHz Gyrotron window have been found -40.3 dB and -0.04 dB respectively. The double disc face cooled structure causes power loss in two discs. In addition, loss in the coolant also has to be taken into account. However, as far as cooling of dielectric is concerned this design is the most effective. The reflection and absorption of RF power depends on the dielectric properties of sapphire as well as coolant liquid. The window geometrical parameters are optimized considering the minimum return loss and the minimum insertion loss by using CST microwave studio. The thermal design of the face cooled window during extreme case of operation, i.e. at saturation has been carried out using ANSYS software and discussed in the paper. The temperature range on the sapphire disc surface has been found to be 350C - 800C. The temperature range on the window disc surface has been found satisfactory. The RF window optimized design allows low heat loads in the ceramic and consequently low temperature increase and low stresses. The power handing capacity of face cooled window has been determined by ANSYS. This design of RF window is capable of handling the thermal and mechanical loading in a 200 kW output power.
Keywords: RF Window; Thermal Analysis; Stress; Cooling Channel; Heat Flux