IAES International Journal of Robotics and Automation (IJRA)
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A weighting system to build physical layer measurements maps by crowdsourcing data from smartphones
Get PDFMobile devices can sense different types of radio signals. For example, broadcast signals. These broadcasted signals allow the device to establish a connection to the access point broadcasting it. Moreover, mobile devices can record different physical layer measurements. These measurements are an indication of the service quality at the point they were collected. These measurements data can be aggregated to form physical layer measurement maps. These maps are useful for several applications such as location fixing, navigation, access control, and evaluating network coverage and performance. Crowdsourcing can be an efficient way to create such maps. However, users in a crowdsourcing application tend to have different devices with different capabilities, which might impact the overall accuracy of the generated maps. In this paper, we propose a method to build physical layer measurements maps by crowdsourcing physical layer measurements, GPS locations, from participating mobile devices. The proposed system gives different weights to each data point provided by the participating devices based on the data source’s trustworthiness. Our tests showed that the different models of mobile devices return GPS location with different location accuracies. Consequently, when building the physical layer measurements maps our algorithm assigns a higher weight to data points coming from devices with higher GPS location accuracy. This allows accommodating a wide range of mobile devices with different capabilities in crowdsourcing applications. An experiment and a simulation were performed to test the proposed method. The results showed improvement in crowdsourced map accuracy when the proposed method is implemented
Multi-objective optimization and linear buckling of serial chain of a medical robot tool for soft tissue surgery
Get PDFThe slender structures of a medical robot may have a tendency to buckling when a force equal to the critical Euler force and an additional disturbance will work on their structures. In this work, eigenvalue problem that describes the linear buckling is under consideration. The main goal of the article is to check when linear buckling phenomenon appears in construction of a medical robot with serial chain due to the fact that for safety reasons of a robot’s work, it is necessary to answer the question, whether the buckling may occur in the robot’s structure. For this purpose, a numerical calculation model was defined by using the finite element method. The values of load factor coefficients that are eigenvalue are determinated and also the eigenvectors that have shapes of deformation for the next eigenvalues are presented. The multi-criteria optimization model was determined to aim for the minimum mass of the effector and the buckling coefficient, from which the Euler force results, for the maximum. The solution was obtained on the basis of Pareto fronts and the MOGA genetic algorithm
Deriving the system equations of unbalanced two-phase induction motor
Get PDFAs there is no system driven especially for the two-phase induction motor fed from unbalanced two-phase supply yet, so we start for derivation the system equations for the said motor to be generally used even for the balanced or unbalanced two-phase supply. In this paper, we will derive a system equation starting from the sequence equivalent circuit for the forward and backwards equivalent circuits, then we will re-arrange the equations with some mathematical assumptions which will lead us to the new system equations. first for the voltage equations then for the current equations and finally for both power and torque equations. Moreover, we will put an example which will cover all cases with specific values and relations charts
Offline drone instrumentalized ambulance for emergency situations
Get PDFIn this paper, an offline drone instrumentalized ambulance (ODIA) mechanism has been discussed. The rapid increase in the urban population directly influences every sector of society. The sectors are maybe food, health care, education, transportation, etc. Normally, it has been observed that when any accidents happen on the urban road or any remote places then, the availability of immediate medical help is very rare. It is not because of the unaware or unavailability of medical facilities rather it happens because of overcrowding on the urban road and geographical odd-isolation of places. Hence, here an ODIA concept has been discussed which uses offline maps and offline first-aid medical videos through which immediate medical help can be made available at the patient end. This model helps to save the life of an accident victim by providing immediate medical attention. The key strength of ODIA is, it is independent of internet service that is why it is more suitable for harsh and hostile environments
Robust control and optimized parallel control double loop design for mobile robot
Get PDFRobots have been used in many applications in the past few decades. Moreover, due to high nonlinearity behavior of these systems, an optimal and robust control design approaches have been considered to stabilize and improve their performance and robustness. The uncertainties of the time delay on the output states of the mobile robot system have a significant influence on the system nominal performance. As a result, the work becomes here to address the influence of these uncertainties on the robot system performance. In order to achieve this objective, the nonlinear controller via sliding mode control (SMC) is designed by selecting a suitable sliding surface dynamics in which the considered robot displacement and tilt angle are sliding on. The lyapunov function is considered here to accomplish the design of the sliding control signals for robot stabilization. Furthermore, the stability of the considered system is guaranteed due to convergence of the lyapunov functions into zero when the state trajectories tend to desired set points. In addition, we consider the trajectory tracking and stabilization of TWBMR system using parallel double loop PID controllers whose controllers gains are tuning via linear quadratic regulator (LQR) approach. Finally, to demonstrate the effectiveness of SMC and PID-LQR design methods, the comparison is carried out when the nominal and uncertain conditions
Design and development of soft robotic hand for vertical farming in spacecraft
Get PDFFor colonization in deep space we need to explore the feasibility of a bioregenerative system in microgravity or artificial gravity environments. The process has various complexities form ranging to biological obstacles to engineering limitations of the spacecraft. Concentration of microbes in the confinements of a spacecraft can be fatal for the crew. In this paper, a solution to the elevated microbial levels by farming using robots is discussed. The soft robotic arm is made up of Asymmetric Flexible Pneumatic Actuator (AFPA). The AFPA under internal pressure will curve in the direction of the side having greater thickness as the expansion of the thinner side (outside radius) will be more than thicker side (inside radius) due to differential expansion and moment induced due to eccentricity. Simulation results demonstrate that bending based on AFPA can meet the designed requirement of application. The AFPA is used for five fingers of the robotic hand. The safe, soft touch and gentle motion of the bellow (AFPA) gives the feel of real human hand. The internal pressure of the AFPA is controlled using a solenoid valve which is interfaced using an Arduino microcontroller for hand like moves. The bending of the fingers and degree of freedom (DOF) of the joints of the hand is controlled using an IMU and flex sensor. Wireless connection of the hand and the control system is implemented using XBee pro 60mW with a range of 1 miles. The pneumatic soft robotic hand is made up of solenoid valve, Mini Compressor, AFPA bellow, and Servos. This soft robotic hand has many advantages such as good adaptability, simple structure, small size, high flexibility and less energy loss. As an extension Manual control of the robot using a virtual reality environment and well as some possible aspects of an automated farming systems can be considered as future additions
Micro controller based asymmetrical multilevel inverter
Get PDFThis paper presents the Asymmetrical multilevel inverter with 1:3 voltage propagation. Switching pulse for Asymmetrical multilevel inverter are generated using embedded controller in m-file using MATLAB. The Asymmetrical multilevel inverter with 1:3 voltage propagation can produce high quality output voltage with less number of switches and voltage sources compare to conventional multilevel inverters. Contrasting other switching schemes, the proposed Switching scheme significantly reduces the Total Harmonic Distortion (THD) and minimize switching losses and reduces the complexity. To evaluate the developed scheme, simulations are carried out through MATLAB and real time implementations are done through microcontroller ARM Cortex™-M0 Core. The simulation and hardware results are presented
Laboratory environment monitoring and specimen transport robots
Get PDFRobots have been used in various areas to replace manpower, reduce costs, and facilitate more effective resource allocation. This study sought to assist the business of the bureau by developing two robots using the Robot Operating System. The developed robots have autonomous intelligent navigation functions and are suited to monitor the environment of the laboratories in the bureau. One robot had a temperature and humidity sensor and an infrared thermal camera, and it could be used to patrol and monitor the laboratory environment. The other robot had drawers in which specimens could be placed; robotic arm in the elevator could coordinate and control elevators, enabling the robot to move and transport specimens autonomously. Plenty of tests were conducted to verify the feasibility and practicality
A new method for handoff target network selection
Get PDFIn wireless communications of fourth generation the expectation to assimilate a hypothetically numerous heterogeneous wireless technologies are happened under consideration of a novel step toward worldwide smooth access. The advancement in wireless networks increases the challenges of mobility management as well the challenges of merging a various number of wireless networks. Out of those the main challenge for smooth movement is the accessibility of consistent vertical (intersystem) and horizontal (intra-system) handoff processes. So to improve the quality of service and to provide always best connected services all the time, the handoff decision algorithm must select an optimum target network from the available candidate networks. The purpose of this paper is to provide a mechanism for selecting an optimum target network from the available networks. This method is devised for maximizing the user satisfaction level, by selecting the “best” network as the handover target network among multiple candidate networks
Path optimization for robots in a constrained workspace
Get PDFIn this work, the classical A* algorithm serves as path planner to generate the optimum path that would avoid collisions and take the start, collisions, and goal as an input and give the optimal path as an output. The work was done in a static environment, so the coordinates of the obstacles are predefined for the planner. The obtained path is just a sequence of points in space, and this path may be considered later the task space and the first step for another sequential operation like mapping from Cartesian space to joint space, topology optimization, dimensional synthesis, etc. The case study was Lab-Volt 5150 manipulator; it is an accurate educational five degree of freedom 5DOF stationary robot driven by five stepper motors