فهرست مطالب abbas aliabadi

The coordinated control of autonomous electric vehicles with in-wheel motors is classified as over-actuated control problems requiring a precise control allocation strategy. This paper addresses the trajectory tracking problem of autonomous electric vehicles equipped with four independent in-wheel motors and active front steering. Unlike other available methods presenting optimization formulation to handle the redundancy, in this paper, the constraints have been applied directly using the kinematic relations of each wheel. Four separate sliding mode controllers are designed in such a way that they ensure the convergence of tracking errors, in addition to incorporating the parametric and modeling uncertainties. The lateral controller is also designed to determine the front steering angles to eliminate lateral tracking errors. To appraise the performance of the proposed control strategy, a co-simulation is carried out in MATLAB/Simulink and Carsim software. The results show that the proposed control strategy has enabled the vehicle to follow the reference path and has converged the errors of longitudinal and lateral positions, velocity, heading angle, and yaw rate. Furthermore, the proposed control system shows promising results in the presence of uncertainties including the mass and moment of inertia, friction coefficient, and the wind disturbances.

Electric storage technologies have different levels of early stages of R&D, and today power systems, especially power grid in Iran, are highly regarded by planners and operators. Because of inherent characteristics of power networks and the presence of many vulnerabillities, using storage systems in power networks is inevitable in order to protect the critical infrastructures and maintain the economy and sustainability of electricity networks. The present study aims to develop the use of electrical storage devices in the distribution network from the passive defense perspective based on (qualitative) and descriptive statistics (quantitative) analysis with help of GAMS software. The country's peak courier survey shows that storage systems have more efficiency compared to power plants. In this investigation, seven types of best-performing batteries are analyzed, based on nominal power indices, efficiency, density, energy, daily insolubility and life span, and Lithium lion batteries are considered to be the most suitable for use in storage systems are introduced as most affordable.

Iranians have a very long history of water harvesting to address water scarcity and the consequences of frequent droughts. Among these strategies, Bandsar is a wide spread indigenous practice, which has been utilized in the central and the southern part of Khorasan province (the northeast Iran). Bandsar in Persian means a series of consecutive bands, berms, levees, or dikes. A Bandsar consists of a series of levees constructed along contour lines and adjacent to an ephemeral stream in a way that occasional floodwater flows can be diverted from the stream into the field(s) of the Bandsar system, to temporarily store the water on the upstream side of the levees. Water gradually penetrates into the soil profile and the accumulated moisture can be used for an appropriate cultivation. Bandsar agriculture has been found to be very unique and sustainable with regards to several key factors such as owners' participation, land-use, and water resource management. In this regard, a field survey was conducted in the suburbs of Sabzevar (57o 4'E, 36o 12'N), which are widely covered with Bandsars, some of which are still being used in the present time. Bandsar's components, construction method, operation, and maintenance have been studied and summarized here according to the information gathered from field observations and face to face interviews with some of the most experienced Bandsar owners.

The degradation trend and descending capacity of Iran’s renge lands due to lack of regular policy and programming in it’s usage, increasing of population, food and protein requirements, are some of problems that turned the ammenment and improvement of rangelands as an essential problem for the users. Eurotia ceratoides plant, due to bushy from, resistance to drought, proper protein percent, simple propagation and… is one of the native plants of desert rangelands that has special importance in arid and semiarid rangelands these charachteristics caused to wide use of this plant in rangelands ammendment programs. The aim of this research was to determine the optimum time for sowing and the best method for sowing of this species in desert rangelands, to use in rangeland management designs. This research was conducted in split plots experimental design frame, in the main plots the sowing date was in 4 treatments (5th of December, 5th of Junury, 5th of Februry and 5th of March) and the secondary plots were included 4 treatments (Heap cropping, Hole cropping, Sowing with disct moldboard, Sowing with plow) with 4 replications in 2 successive years of 1996 and 1997 in plots with 6 * 4 dimensions. The number of established plant per plot was determined and the data analysis was done by SAS program. Results showed that, the best method of sowing in establishment percent of Eurotia were sowing by plow and disc, heap cropping and hole cropping respectirely. The dates of 5th of December and 5th of Junury had more establishment percent. The plow and disc methods in 5th of December had the most establishment percentage.