controller

Due to the drastic change in aerodynamic parameters, the problem of controlling the landing mode will be much more complicated than the high altitude flight. On the other hand, the presence of obstacles in the way of the bird's landing is another condition that should be considered in the design of the controller. Thus, according to the above, it is necessary to use the predictive controller to solve the problem. This controller inherently has a high resistance to model change. Also, if this controller is used in a restricted manner, it can be used to bypass obstacles in the path of movement during landing. The aim of this paper is to control the system for automatic landing by means of model-based pre-interlinear control. The reason for using the pre-interlinear controller is the presence of obstacles in the path of movement and the fulfillment of the constraints in the environment to remove the obstacles. As a final result, this controller is designed in such a way that the effect of external disturbances on the bird is minimized and the stability of the system is not jeopardized by the emergence of model uncertainties. Also, in this method, the effect caused by the delay of the external navigation system is taken into account in the closed loop system and the stability of the system is guaranteed. Finally, the proposed controller design is calculated for a real bird model and its performance simulation in the presence of obstacles, lateral and longitudinal wind is presented.

In this investigation, using the fractional calculus, a controller for trajectory control of a quadrotor is designed. As a matter of fact, one of the most important challenges in quadrotors is changing the mass of the quadrotor for carrying loads. In this paper, the controller is designed adaptive to show appropriate response in the presence of changing mass. For designing this controller, the sliding mode controller is utilized, which the sliding surfaces are considered as a fractional model. The results of this study demonstrate the effectiveness of the fractional-order controller for trajectory control of a quadrotor with changing the mass parameter. Moreover, simulations illustrate that by changing the fractional-order a new controller can be designed which can do the same mission with less control effort. Therefore, utilizing the fractional controller, the Dynamic Load Carrying Capacity (DLCC) of a quadrotor can be increased. The results show that by considering fractional-order = 0.275, the DLCC is maximized. The innovation of this work is the investigation of fractional order controllers in determining the DLCC, which shows that by setting a certain value, the DLCC can be increased by about two times compared to the classical sliding mode control.

The process of major repairs and manufacturing in diesel engine repairing and remanufacturing factories is very important. Reducing the cost of repairing and the time of the processes is depended on the amount of capacity and work speed. One of the equipment that increases the capacity and speed of work is a device called a heavy equipment rotary table. In this article, research and investigation for the construction of a heavy equipment rotary table is targeted. The importance and application of items that should be considered for the design of this product have been collected. The designing of this device has been done in CATIA and Abaqus software. The loading capacity of the device was 15 tons and the torque capacity was 15000 N.m. The influential and critical components of the device were simulated using Abacus finite element software, and the geometric dimensions of each component were precisely determined. St37 carbon steel sheets were used to make the body of the machine. The standard components and parts of the device were also selected according to the mechanical and functional characteristics of the device. Finally, the rotary table device was built according to the extracted functional models and its function was evaluated successfully.

In this article, orbital rendezvous and docking as a key and important subject that has fundamental and important applications in the field of space has been studied. the main objective of this paper will be the investigation of the general and important sections of a rendezvous and docking mission. importance and examples of the Application of the problem and also common steps in a rendezvous and docking mission, problem-solving approaches and practical methods have been explained in this article. System control is an important part in the mission of rendezvous and docking. Thus, the practical controllers and some of their advantages and disadvantages are expressed and simultaneous position and attitude control has been studied as an important challenge. In the following, some common approaches and sensors in an orbital rendezvous and docking problem are presented and finally, examples of laboratory equipment as an important tool are provided.

The controller of the hybrid electric vehicle determines the combustion engine start-stop time, the operation points, and regenerative brake energy. The Controlling approach of hybrid electric vehicles controls the amount of needed fuel in every driving situation. In the present study, the thermostat strategy is implemented along with fuzzy logic control and compared to the classic thermostat strategy. The fuel consumption is compared in two different strategies. GT-power and Simulink software are implemented to simulate the series hybrid electric model. The numerical model is compared and validated with experimental data. The validated numerical model calculates the vehicle fuel consumption in the new European driving cycle. Results show that the use of fuzzy logic control reduces the fuel consumption of series hybrid electric vehicle 4 percent compared to the classical control strategy.

This paper discusses the design and development of a control system for the internal loop subsystem of an AUV. Using the multi-input multi-output (MIMO) nonlinear system state space approach, the linearized equation is obtained, and the desired conversion function is extracted from the corresponding linear equation. Then first examine the conversion function exposed to PID controller and then to PID_fuzzy type 2 controller, then using multi-objective genetic algorithm, fuzzy controller parameters including rules, input and output membership functions and optimal output gain Turns. And the results obtained in this method will be compared with similar previous worksThe proposed method in this research will be able to significantly improve the control parameters of the maximum value of the metamorphosis and the settling time of the system state variables. Of course, the proposed method will have a high volume of calculations in the nonlinear model and the slowness of the simulation process compared to previous works, which will also provide solutions to solve it.

In this paper, the performance of a closed-loop dynamical system is investigated in the presence of controller, actuator and sensor. Usually, in analysis, the dynamics of sensor and actuator are assumed to be ideal and they are ignored however these components have dynamic practically. Since, the function speed of the sensor and the actuator must be more than the speed of dynamic system, it is reasonable to separate the equations of the closed-loop system, in the presence of the actuator and sensor, into slow equations (the dynamical system’s equations) and fast equations (equations of actuator and sensor). This paper focuses on this issue and the modeling of the closed-loop system in the structure of singular perturbation systems with the breakdown of fast and slow operating modes. Some theorems in the area of stability analysis and stabilization of the closed-loop system are given. Finally, simulations have been carried out for a mechanical example and it has been shown that the dynamics of the actuator and sensor should be faster than the dynamic system to achieve the desired results.

The aim of this paper is the application of quadcopters to significantly increase the probability of discovering hidden targets by providing an upper sight view of the targets of different points for professional snipers. The mentioned process is performed by a quadcopter equipped with a camera and a transmitter, which is made, assembled, and studied from the beginning according to the requirements of the project, and some necessary studies have been done on its parts and capabilities. Its main flight controller is capable of supporting the required modules and exchanges data online with the radio control and computer. A novel navigation module equipped with a laser rangefinder is also designed in order to calculate and generate output of remote GPS point with the required components, and its controller is programmed according to global locational algorithms. By pressing a button, the coordinate of a specific remote point is created and transmitted to the computer by a serial port. According to a point mission, the quadcopter moves to the announced coordinate and sends the image from the top view with its camera and transmitter. In this way, for the target point, a second image is also provided for the user, besides the direct image which exists through the direct line of sight, which doubles the probability of discovering the targets. The manufacturing process is based on available equipment in the market. Finally, some tests are performed and the results and errors are calculated.

The use of driver assistance systems in cars is increasing since it helps the driver and reduces his/her activities and fatigue. Among these systems, the Adaptive Cruise Control (ACC) system with longitudinal dynamic automatic control is at the center of attention. With such automation, the role of the driver changes from an operator to a supervisor. Therefore, providing safety and passenger comfort in these systems is of particular importance. It should be noted that ACC can greatly affect traffic flow and can perform better than a human driver. In this paper, various control functions will be examined focusing on their application in the ACCs control section. By analyzing the advantages and disadvantages of each of the studied functions, their effects on various components such as safety and comfort of vehicle passengers are studied. Moreover, the ACC sensitivity road and weather conditions are also addressed. At the end, the horizons ahead of this topic are presented which helps to improve the past works as much as possible.

Gas turbines have a wide range of application in different industries. There are different models of the gas turbine for its analysis and diagnosis. In this paper, a hybrid model is considered for the gas turbine. This model combines thermodynamic relations and data-based equations which cause to eliminate dynamic loops of thermodynamic relations. Also, the compressor performance curve is considered in the proposed model which leads to noticing physical and geometric characteristic of a gas turbine. The model is dynamic and nonlinear that cause to adapt to a different condition and increase the accuracy of modeling. The model is accurate, simplified and nonlinear state space form. For these reasons, the model is suitable for analyzing of controllers and observers. The proposed controller is a new sliding model controller for implementing in the model. The controller is based on the l_1 norm and frequency analysis. Since the sliding mode is robust and the l_1 norm is optimizer than the l_2 norm, the controller tracks fuel command with acceptable accuracy and minimizing the control fluctuations.
Also, the data that is used in this paper is the data of an industrial gas turbine (IGT25) of Iran's national turbine which is logged in different ambient and functions conditions.

Magnetic levitation systems are recently used for contactless transportation of objects. In magnetic levitation, the object can be levitated by actively controlling the magnetic field based on the measured air gap between the object and the levitator. These systems are affected from the velocity of moving objects, the distance of suspended object from magnetic core and intensity of magnetic field as well as dynamic loads. Environmental noises cause instability in these systems. In this paper, a contactless transportation system has been proposed for vertical transportation of a metal sphere. PID controller was used to stabilize the transportation. The performance of this transportation system at different vertical speeds was analyzed. Results show that the suggested method could precisely monitor sudden moves. The proposed magnetic suspension system can maintain the stability of suspended object at the maximum velocity of 4.53m/s in upward movement.

Full feedback data is mostly essential in control design. The measurement of the variation of flexible joint robot (FJR) actuators is not easy as the measurement of the changes of FJR links’ angles. The measurement of the states is also affected by noise, and the disturbance in the workspace of the robot is not ignorable. Hence a state observer or a nonlinear estimator is necessary to improve the performance of the dynamic system. The state-dependent Riccati equation (SDRE) is one of the most promising nonlinear optimal control methods for estimating variables of systems. Systematic procedure, simple structure, and incorporating wide range of systems (under observability condition) are some advantages of SDRE method. The majority of nonlinear techniques linearize the model, but the SDRE directly uses the nonlinear state space; it is one of the reasons for its precision and flexibility in design with respect to other methods. The goal of this work is to merge the SDRE controller and estimator simultaneously to reduce the state error of the system in presence of external disturbance and measurement noise. So, first, the controller and the observer formulation has been stated. Then, the procedure has been applied to design and to simulate a 3 DOF robot arm with flexible joints. Next, the process has been tested experimentally using Scout robot and the simulation results have been verified. Finally, the proposed method of this paper has been compared with the optimal sliding mode.

An Aerial Robot or Unmanned Aerial Vehicle (UAV) is an aerial vehicle that provides its flight condition using aerodynamic forces. Also, this vehicle can be named as an autonomous robot. This robot is an under-actuated system and it is inherently unstable. Thus, the control of this nonlinear system is a problem for both practical and theoretical interest. So, the goal of this research is to contrast with highly nonlinear dynamic system of Octorotor that its control is difficult in many cases and it causes existence of instability in this Unmanned Aerial Vehicle (UAV). At the first, the structure of Octorotor is studied in this paper in order to increasing power, more carrying and increment of resistance into changing and distribution. Also, the electronic and mechanic of this robot is studied in some sections. Then, in the following, in order to attitude control of robot with introduction of dynamic system, one of the most common implemented controllers is applied on this robot. Initially, this process is done on the dynamic model of robot by Matlab/Simulink software and finally, implementation of this controller is applied on a fabricated Octorotor during a real flight in autonomous trajectory tracking in outdoor environment. At last, the study of sensors results is also shown.

One of the main problems of marine transportation is passengers and crew's seasickness due to longitudinal movement of vessels. When marine structures excited by waves, acceleration of heave and pitch motion will be exceeded. So vessel's motion should be reduced as much as possible to increase the comfort and safety of passengers. By Using appropriate control algorithms can be reduce ship movements in waves. Longitudinal motion control in waves for vessels such as catamaran is one of the main priorities of design. So, the control surfaces like interceptor and hydrofoil are used for reduce longitudinal motion of vessel. These control surfaces by applying variable forces against wave loading can reduce longitudinal motion.
Nowadays, artificial neural networks are used a lot in the design of control systems. Neural networks are able to model complex dynamics systems, and design appropriate controller them. In this study catamaran heave motion is modeled and then multilayer neural network is taught for control heave motion. As will be shown, designed neural network controller has acceptable accuracy for standard inputs.

In this paper, the method of modern control approach for the design of controller and observer is used. Other functions such as neural controllers - or fuzzy sliding mode control can be found in this work and the results are compared. First, a dynamic model of the servo valve is intended for the governing equations in state-space form expression are obtained. Due to the system integrator is expressed by the non-zero, The servo system of a full-order state observer pole positioning method to measure the dominant pole, Bessel and ITAE is designed and evaluated. Response to a step input to the system is designed and the observer's response to initial conditions. The curves show the comparison between systems is designed to do.