Elevation, pitch and travel axis stabilization of 3DOF helicopter with hybrid control system by GA-LQR based PID controller

This research work presents an efficient hybrid control methodology through combining the traditional proportional-integral-derivative (PID) controller and linear quadratic regulator (LQR) optimal controlher. The proposed hybrid control approach is adopted to design three degree of freedom (3DOF) stabilizing system for helicopter. The gain parameters of the classic PID controller are determined using the elements of the LQR feedback gain matrix. The dynamic behaviour of the LQR based PID controller, is modeled and the formulated in state space form to enable utlizing state feedback controller technique. The performance of the proposed LQR based LQR controller is improved by using Genetic Algorithm optimization method which are adopted to obtain optimum values for LQR controller gain parameters. The LQR-PID hybrid controller is simulated using Matlab environment and its performance is evaluated based on rise time, settling time, overshoot and steady state error parameters to validate the proposed 3DOF helicopter balancing system. Based on GA tuning approach, the simulation results suggest that the hybrid LQR-PID controller can be effectively adopted to stabilize the 3DOF helicopter system

Balancing a Segway robot using LQR controller based on genetic and bacteria foraging optimization algorithms

A two-wheeled single seat Segway robot is a special kind of wheeled mobile robot, using it as a human transporter system needs applying a robust control system to overcome its inherent unstable problem. The mathematical model of the system dynamics is derived and then state space formulation for the system is presented to enable design state feedback controller scheme. In this research, an optimal control system based on linear quadratic regulator (LQR) technique is proposed to stabilize the mobile robot. The LQR controller is designed to control the position and yaw rotation of the two-wheeled vehicle. The proposed balancing robot system is validated by simulating the LQR using Matlab software. Two tuning methods, genetic algorithm (GA) and bacteria foraging optimization algorithm (BFOA) are used to obtain optimal values for controller parameters. A comparison between the performance of both controllers GA-LQR and BFO-LQR is achieved based on the standard control criteria which includes rise time, maximum overshoot, settling time and control input of the system. Simulation results suggest that the BFOA-LQR controller can be adopted to balance the Segway robot with minimal overshoot and oscillation frequency

Spectrophotometric Determination of Cerium in Some Ore in Kurdistan Region – Iraq

A simple and Sensitive Spectrophotometric method was observed for trace measurement of Cerium (IV) in different serpentinite rocks in two different positions in Kurdistan region of Iraq. The method is depended on absorbance measurement at (490 nm.) for the red complex (Ce - Sulphanilic acid) at pH = 4.75 reproducible results were obtained (Recovery 98 – 103) % for both ores and synthetic Samples of cerium in trace levels. Keywords: red complex, serpentinite rocks, spectrophotometric, ceriu

Design and Analysis of a 4GHz Low Noise Amplifier

The Gallium Arsenide Field Effect transistor (GaAs FET) is experiencing a widespread acceptance in space and terrestrial systems due to its low noise, high gain and frequency characteristics unmatched by bipolar devices. This paper describes a design of a 4 GHz low noise amplifier with GaAs FETs using the scattering parameters method. Special attention is given to overall noise/gain optimization in the band of interest. The Smith Chart is used extensively to match the two-port device with microstrip networks. Analysis and performance of the amplifier are presented

Adsorption of Congo Red Dye from Aqueous Solution onto Natural and Modified Bauxite Clays

The adsorption behavior of congo red dye from its aqueous solutions was investigated onto natural and modified bauxite clays. Both bauxite and modified bauxite are primarily characterized by using, FTIR, SEM, AFM, and XRD. Several variables are studied as a function of adsorption including contact time, adsorbent weight, pH, ionic strength, particle size and temperature under batch adsorption technique. The absorbance of the solution before and after adsorption was measured spectrophotometrically. The equilibrium data fit with Langmuir model of adsorption and the linear regression coefficient R2 is found to be 0.9832 and 0.9630 for natural and modified bauxite respectively at 37.5°C which elucidate the best fitting isotherm model. The general shape of the adsorption isotherm of congo red on natural and modified bauxite is consistent with (H-type) on the Giles classification. Different thermodynamic parameters such as Gibb's free energy, enthalpy and entropy of the on-going adsorption process have also been evaluated. The thermodynamic analyses of the congo red adsorption on natural and modified bauxite indicate that the systems are endothermic in natur

Real-time system identification using deep learning for linear processes with application to unmanned aerial vehicles

This paper proposes a novel parametric identification approach for linear systems using Deep Learning (DL) and the Modified Relay Feedback Test (MRFT). The proposed methodology utilizes MRFT to reveal distinguishing frequencies about an unknown process; which are then passed to a trained DL model to identify the underlying process parameters. The presented approach guarantees stability and performance in the identification and control phases respectively, and requires few seconds of observation data to infer the dynamic system parameters. Quadrotor Unmanned Aerial Vehicle (UAV) attitude and altitude dynamics were used in simulation and experimentation to verify the presented methodology. Results show the effectiveness and real-time capabilities of the proposed approach, which outperforms the conventional Prediction Error Method in terms of accuracy, robustness to biases, computational efficiency and data requirements.Comment: 13 pages, 9 figures. Submitted to IEEE access. A supplementary video for the work presented in this paper can be accessed at: https://www.youtube.com/watch?v=dz3WTFU7W7c. This version includes minor style edits for appendix and reference

Impact Resistance of GFRP Reinforced Concrete One-Way Slabs

Concrete structures are usually subjected to short-term dynamic loads besides long-term static loads. Tensile strength and energy dissipation characteristics are reduced as a result of these loads as long as the concrete is weak in resisting impact loads. This paper studies the behavior of one-way concrete slabs reinforced with glass fiber reinforced polymer (GFRP) under an impact load. A comparison one-way concrete slabs reinforced with GFRP and normal steel has been done. Six slabs with dimensions of (4000*1000*180) mm are cast. Three specimens for each type of slab have been constructed and tested under impact load. A simple device has been made mainly to subject an impact load by applying a load of a weight 7 Kg that falls in the center of the slab from two different heights,1000 mm and 2000 mm. The concrete strain at different locations is measured during a specific time. Results have been taken as an average of three specimens for each type of slab. The results showed that the slabs reinforced with GFRP bars has a better behavior than the ones reinforced with normal steel. The strain of the slabs with GFRP is 25% less than the slab with steel bars, also the time interval was 37.5% less. The value of strains is greater in the short direction than the other directions

Effects of climate change on metabolite accumulation in freshwater and marine cyanobacteria

Global climate change and anthropogenic nutrient inputs are responsible for increased frequency of cyanobac- terial blooms that potentially contain 55 classes of bioactive metabolites. This study investigated the effects of CO2 availability and concomittant pH levels on two cyanobacteria that produce microcystins: a marine cf. Syne- chocystis sp. and a freshwater Microcystis aeruginosa. Cyanobacterial strains were semi-continuously cultured in mesotrophic growth media at pH 7.5, 7.8, 8.2, and 8.5 via a combination of CO2 addition and control of alkalinity. The cell concentration between treatments was not significantly different and nutrient availability was not lim- ited. Concentration of most known cyanobacterial bioactive metabolites in both cyanobacterial strains increased as CO2 increased. At pH 7.8, bioactive metabolite intracellular concentration in M. aeruginosa and Synechocystis was 1.5 and 1.2 times greater than the other three treatments, respectively. Intracellular concentration of mi- croginin in M. aeruginosa at pH 7.5 was reduced by 90% compared to the other three treatments. Intracellular concentration of microcyclamide-bistratamide B was lower in M. aeruginosa and higher in Synechocystis at ele- vated CO2 concentration. M. aeruginosa products were more diverse metabolites than Synechocystis. The diversity of accumulated metabolites in M. aeruginosa increased as CO2 increased, whereas the metabolite diversity in Syne- chocystis decreased as pH decreased. Overall, intracellular concentration of bioactive metabolites was higher at greater CO2 concentrations; marine and freshwater cyanobacteria had different allocation products when exposed to differing CO2 environments