Sharif Digital Repository

Many industrial systems have on/off actuators. Traditionally, these systems are controlled using traditional control methods, like PID controller. The performance of this controller is not ideal for these systems, especially in term of transient response and power consumption. Due to the large number of constraints for these systems, to improve the performance of them, it is necessary to use the model predictive control technic. The decision variables of these systems are integer, hence it is necessary to develop the model predictive control method based on integer programming, which is the subject of this thesis. The main challenge in the development of this model predictive control method,... 

This thesis is concerned with an optimal trade-off between communication overhead and the number and size of neighborhoods in a distributed optimal control technique for large-scale systems that is based on the Jacobi iteration and two-layer architecture for communication. Although this method efficiently reduces computational overhead, continuous and proper data transfer between subsystems that are very often far from each other, is required to achieve an acceptable performance. However, limited transmission bandwidth and short communication range result in significant communication overhead. This causes significant time latency between measurement and applied calculated control actions,... 

The present thesis is concerned with design and development of automated irrigation system pilot. This system is obtained by equipping each regulating gate of irrigation network with a controlling hardware. This hardware is designed and developed in this project for Iran’s regulating gate, which are either slide gate or radial gate. This hardware consists of a) Ultrasonic sensor for measure gate upstream water level, b) Wireless modem for exchanging measurements between automated gates, c) controller, d) Electric motor and driver, e) shaft encoder and f) adaptor. The satisfactory performance of this hardware is shown via several experiments on the pilot  

Abstract: In this dissertation, the problem of tracking and stabilization of nonlinear dynamic systems over the packet erasure channel is addressed. Using the idea of linearization of nonlinear system around current working point, and by the design of an encoder, decoder, and controller for the linearized system, state tracking and reference tracking of the nonlinear system are addressed. To prove the traking and stability of the system, the strong law of large numbers and the dwell time approach are used. By computer simulations, the theoretical development is applied on the nonlinear dynamic of the unicycle model, which is a suitable model for autonomous vehicles, such as drones, unmanned... 

In this MSc. thesis a dongle and gateway are designed and developed for outdoor applications. In addition, a mesh networking protocol is developed for these dongle and gateway that does not impose the deficiencies of the other available protocols in the literature. The developed dongle supports a Lora LPWAN module, which is very popular in IIOT applications. It also supports the ESP32 module, which is a very popular IIoT module in the WiFi family. The developed dongle supports one-wire temperature and humidity sensor, analog and digital sensors, CAN and RS485 data communication protocols and it is able to produce on/off outputs. The developed gateway supports LAN and 4G protocols in order to... 

A distributed model predictive control with two-layer structure for communication is presented in the present thesis for elimination of the propagation and amplificationphenomenon of the upstream transient errors in automated irrigation networks. This phenomenon results in the saturation of actuators in long automated irrigation channels and therefore it results in significant reduction in the quality of service of the irrigation network. Hence, the elimination of this phenomenon in long irrigation channels is necessary, in which a distributed model predictive control with two-layer structure for communication is presented in the presentthesis for elimination of this phenomenon. Feasibility,... 

The objective of this MSc. thesis is to study the impact of the reactive method and the enhanced reactive method on enhancing the exploitation efficiency of Iran's offshore oil reservoir. This is achieved by enhancing production and the recovery factor of the reactive methods with respect to the currently used proactive method. Unlike the currently used proactive method that implements a fixed rate injection strategy, in this MSc. thesis water is injected to reservoir with multi-rate for the pressure stabilization of the reservoir. In order to scale up this strategy, the ensemble Kalman filter is used to frequently update the reservoir mathematical model using the available measurements from... 

With the expansion of industrial Internet of Things systems in automation, control, and monitoring processes, the need for powerful servers for real-time processing, calculations, and decision-making in large-scale applications was felt, and implementation and use of this in such applications was one of the problems in this field. The base of this problem was also caused by its central structure, where processing, calculations, and decision-making took place in a central server, which even caused the existence of other risks like security and resilience problems against disconnecting the server layer with sensor and actuator layer and also hacker attacks on the central server. To come over... 

With the expansion of industrial Internet of Things systems in automation, control, and monitoring processes, the need for powerful servers for real-time processing, calculations, and decision-making in large-scale applications was felt, and implementation and use of this in such applications was one of the problems in this field. The base of this problem was also caused by its central structure, where processing, calculations, and decision-making took place in a central server, which even caused the existence of other risks like security and resilience problems against disconnecting the server layer with sensor and actuator layer and also hacker attacks on the central server.To come over... 

The following thesis is concerned with the effect of channel feedback in tracking and stability of linear Gaussian systems over Additive White Gaussian Noise (AWGN) channel when the decoder is the Kalman filter and encoder is the innovation encoder. When the feedback channel is described by a noisy link or a random switch, it is shown that stability is not possible for unstable systems. But for stable systems, an innovation encoder, Kalman filter decoder and a certainly equivalent controller for tracking and stability are presented. When the feedback channel is described by a deterministic switch, for both stable and unstable systems, an innovation encoder, Kalman filter decoder and a... 

This thesis is concerned with stability and tracking of nonlinear noisy Lipschitz systems over the packet erasure channel with feedback acknowledgment when system and measurement are due to bounded noises. The desired stability and tracking criteria is bounded stability and tracking in probability. Two approaches are adopted to address the desired stability and tracking performance, one is based on the Chebyshev inequality and the other is based on the Binomial distribution. It is illustrated that when the erasure probability is large, the approach based on the Chebyshev inequality provides a better bound for stability and tracking in probability; while, when the erasure probability is... 

This work is concerned with new methods for decomposing large scale systems into disjoint neighborhoods with specific size determined a priori by the communication load of the Jacobi based distributed optimization technique. This iterative optimization technique has the following features: it handles hard control input and state constraints; and for convex optimization problem, in the limit, its solution converges to the optimal solution. The proposed decomposition techniques cluster subsystems based on the strength of control inputs interaction. Three techniques are proposed. The first technique is an extended version of REGA. The second is an extended version of Participation... 

In this thesis, design and development of turbine flow meter for measuring of the volumetric flow rate of open channel and calibration system for it have been developed. This system has been constructed from two main sections, namely: software and hardware sections. The hardware section consists of a turbine, turbine chamber, Tachogenerator, microcontroller, and an ultrasonic sensor for measuring of channel water level. The turbine is located in exposure of water stream, and hence can be rotated in proportional to the water stream in which the value of rotation is measured by the tachogenerator, and then sent to the microcontroller, in order to calculate the velocity of water stream. At the... 

In this thesis, at first upstream transient error propagation and amplification phenomenon is introduced. Then, the previous methods to attenuate this phenomenon are presented. To overcome this drawback, a new method that is based on feed-forward and off-take disturbance estimation and lost data reconstruction in wireless communication is presented. In this thesis, an estimation of unknown off-take disturbance at the present time is approximated or in fact predicted using the last data. Also, in the presented method, the lost data is reconstructed using two different methods. At the end, the satisfactory performance of the proposed control method is illustrated by many computer simulations  

The following thesis is concerned with the control of automated irrigation channel using model predictive control in order to eliminate upstream transient error propagation and amplification phenomenon. It is illustrated in the literature that one way of dealing with this phenomenon is to solve a constrained optimization problem at each receding horizon. However, this problem becomes infeasible for automated irrigation channels. Several methods in the literature have been proposed that exploit terminal constraints to guarantee the feasibility of this problem. Finding these constraints, however, is extremely time-consuming as well as impractical for large-scale automated irrigation channels.... 

One of the important issues in the field of telecommunications is the optimization of coding algorithms. Especially, in the field of the Internet of Things (IoT) due to the low processing power and the limitation in the energy storage of devices, the needs for such optimized algorithms are more essential. One effective method to improve coding algorithms in the transmission of messages is obtained by paying more attention to the amount of information contained in each part of the message and transmit information accordingly. Some coding methods have addressed this issue indirectly, but they do not pay enough attention to this practical issue. Based on the simple but practical idea mentioned... 

As latency reduction is a key objective of upcoming mobile standards such as 5G, control applications over such channels have become of high interest in recent years. In this thesis, we will consider the problem of control over fading channels modeled by finite-state Markov chains. We will combine communication and control theory aspects of the problem and study stability of linear discrete-time plants which communicate with the controller over such fading channels. Two different scenarios are assumed for channel state information availability at encoder side, and the sufficient condition of almost sure asymptotic stabilizability is derived for each scenario. We will then examine the... 

This dissertation discusses the development of dimensionless correlations for predicting hydrodynamic parameters and CFD simulation of gas-solid two phase flow in conical fluidized beds. This research mainly focuses on the impact of particle size distribution on hydrodynamic parameters. The first section describes the experiments that were carried out with a number of gas–solid systems in a conical column to study certain important characteristics of the fluidized bed. Generalized empirical correlations, based on dimensionless analysis, have been developed in order to predict minimum fluidization velocity, minimum velocity of full fluidization, maximum pressure drop and bed expansion ratios.... 

To suppress stick-slip oscillations a controller is designed. However, because the lack of rotary speed at the surface, two approaches to implement this controller is considered: 1) Using an observer to estimate the rotary speed, 2) Using acoustic communication. To implement the second method, we confront several challenges including delay in the feedback loop and noise in communication system. In this thesis, a controller is designed based on prediction of the current rotary speed using its delayed value. It is shown that this system is less sensitive to uncertainty in system parameters compared to the controller based on observer. The performance of both systems in terms of settling... 

Because of the increasing use of distributed computing and edge computing patterns, broadcast communications are becoming increasingly important. This communication should be such that each node can deliver its information to all or part of the network nodes. The quantity of delay should be small enough to not disturb the rest of the control processes.
There are different topologies such as Mesh, Tree and Star networks, each of which has efficiencies according to the type of its media access control. In this thesis, a clustering architecture is proposed using the combination of Frequency Division Multiple Access with Carrier Sensing Multiple Access, and mathematical analysis is performed...