Backstepping Controller for Mobile Robot in Presence of Disturbances and Uncertainties

The objective of this work is to devise an effective control system for addressing the trajectory tracking challenge in nonholonomic mobile robots. Two primary control approaches, namely kinematic and dynamic strategies, are explored to achieve this goal. In the kinematic control domain, a backstepping controller (BSC) is introduced as the core element of the control system. The BSC is utilized to guide the mobile robot along the desired trajectory, leveraging the robot’s kinematic model. To address the limitations of the kinematic control approach, a dynamic control strategy is proposed, incorporating the dynamic parameters of the robot. This dynamic control ensures real-time control of the mobile robot. To ensure the stability of the control system, the Lyapunov stability theory is employed, providing a rigorous framework for analyzing and proving stability. Additionally, to optimize the performance of the control system, a genetic algorithm is employed to design an optimal control law. The effectiveness of the developed control approach is demonstrated through simulation results. These results showcase the enhanced performance and efficiency achieved by the proposed control strategies. Overall, this study presents a comprehensive and robust approach for trajectory tracking in nonholonomic mobile robots, combining kinematic and dynamic control strategies while ensuring stability and performance optimization

Mobile Robot Navigation Using Planning Algorithm and Sliding Mode Control in a Cluttered Environment

The research contribution of the present work is to solve the path planning and path tracking problems in static and dynamic environments. A new Planning Navigation Algorithm Technique is developed in order to solve the problem of navigation with obstacle avoidance. The basic idea of this algorithm searches for a safe path for navigation. First, this algorithm is focused to identify an optimal collision-free route to a spatially defined objective. Then, in each displacement, the developed algorithm handles to maximize the distance between the obstacles and minimize the distance to the goal. This is to obtain the optimal trajectory for navigation. On the other side, a sliding mode controller is adopted to solve the tracking trajectory task. The basic idea of this control system is to allow the robot mobile to track the desired trajectory with minimum error. In addition, the comparative study between the proposed approach and the previous work is presented in order to demonstrate the satisfaction of the proposed strategy. Finally, simulation results which are developed using Matlab software are presented to show the robustness and efficiency of the developed algorithm and the reactivity of the proposed sliding mode controller

Molecular cloning and in silico analysis of three somatic embryogenesis receptor kinase mRNA from date palm

We report here the isolation and characterizations of three somatic embryogenesis receptor kinase (PhSERK) genes from palm date by a rapid amplification of cDNA ends (RACE) approach. PhSERKs belong to a small family of receptor kinase genes, share a conserved structure and extensive sequence homology with previously reported plant SERK genes. Sequence analysis of these genes revealed the sequence size of 11051 pb (PhSERK1), 7981 pb (PhSERK2) and 10510 pb (PhSERK3). The open reading frames of PhSERK1, PhSERK2 and PhSERK3 are 1914 pb, 1797 pb and 1719 pb respectively. PhSERKs belongs to the LRR-type cell surface RLKs, which possess a number of characteristic domains. These include an extracellular domain (EX) containing a variable number of LRR units, signal pepetide (SP) immediately followed by a single transmembrane domain (TM) and an intracellular kinase domain. The phylogenetic tree shows that the protein PhSERK1, PhSERK2 and PhSERK3 clustered within monocots SERKs proteins groups. We also predicted the secondary and tertiary with ligand binding sites structure of the protein PhSERKs

Increased Biological Activity of Aneurinibacillus migulanus Strains Correlates with the Production of New Gramicidin Secondary Metabolites

Acknowledgments This project was funded by the Government of Kuwait (to FA) and the European Union Seventh Framework Programme under grant agreement 245268 (ISEFOR; to LB and SW). Further support came from the SwissBOL project, financed by the Swiss Federal Office for the Environment (grant holder LB) and the Sciex–Scientific Exchange Programme (http://nms.ch/) (NMS.CH; to LL and LB). LL is indebted to the Ministry of Education, Science, Research and Sport of the Slovak Republic for financial support in the frame of the project “VEGA 1/0061/16” and “VEGA 1/0046/16”. Funding This project was funded by the Government of Kuwait (to FA) and the European Union Seventh Framework Programme under grant agreement 245268 (ISEFOR; to LB and SW). Further support came from the SwissBOL project, financed by the Swiss Federal Office for the Environment (grant holder LB) and the Sciex–Scientific Exchange Programme NMS.CH (to LL and LB). LL is indebted to the Ministry of Education, Science, Research and Sport of the Slovak Republic for financial support in the frame of the project “VEGA 1/0061/16.”Peer reviewedPublisher PD

Turning Point and Free Segments Strategies for Navigation of Wheeled Mobile Robot

The basic idea of the developed work is to solve the problem of mobile robot navigation with obstacle avoidance and the trajectory tracking problem in simple and complex environments. The research contribution aims to develop a strategy of navigation based on the turning point and the free segments algorithms. Indeed, a turning point method is developed in order to solve the problem of navigation in a simple environment. Then, the free segments approach is applied in order to solve the problem of obstacle avoidance in a complex environment. The second part of this paper aims to solve the problem of trajectory tracking. For this reason, a sliding mode controller is proposed as a solution to control the stability of the mobile robot. Finally, some simulation results which are developed using Matlab software are given to prove the validity of the developed work

Molecular characterization and evolution studies of a SERK like gene transcriptionally induced during somatic embryogenesis in Phoenix Dactylifera L v Deglet Nour

A somatic embryogenesis receptor kinase like (SERKL) cDNA, designated PhSERKL, was isolated from date palm (Phoenix Dactylifera L) using RACE PCR. PhSERKL protein shared all the characteristic domains of the SERK family, including five leucine-rich repeats, one proline-rich region motif, a transmembrane domain, and kinase domains. Phylogenetic analyses using PHYLIP and Notung 2.7 programs suggest that the SERK proteins of some plant species resulted from relatively ancient duplication events. We predict an ancestor protein of monocots and dicots SERK using FASTML program. Somatic embryogenic cultures of date palm were established following transfer of callus cultures to medium containing 2, 4-dichlorophenoxyacetic acid. The role of PhSERKL gene during establishment of somatic embryogenesis in culture was investigated using quantitative real-time PCR. PhSERKL gene was highly expressed during embryogenic competence acquisition and globular embryo formation in culture. Overall, levels of expression of PhSERKL gene were lower in nonembryogenic tissues and organs than in embryogenic callus

Discovery and Potential of SNP Markers in Characterization of Tunisian Olive Germplasm

Single Nucelotide Polymorphisms (SNPs) have become the most widely used markers in many current genetic applications. Here we report the discovery of nine new SNPs in olives by direct partial sequencing of two genes (OEX and OEW) in sixteen Tunisian cultivars. The SNP markers were then used to genotype 24 olive cultivars and assess the level of genetic diversity. Power of discrimination of SNP markers was then compared to that of microsatellites (SSRs). A combination of SSR and SNP markers was finally proposed that can be used for cultivars identification in juvenile step or for oil traceability