11-08-2014, 01:31 PM
Controller Designing Of MIMO System
[attachment=66537]
1. ABSRACT
In this paper, some information about the MIMO system, its transfer functions and block diagram is given. In addition, problems related to MIMO systems such as process interactions are presented. Also different strategies such as decoupling method, to reduce these control interactions are presented. Finally, relative gain array (RGA) is applied here for pairing of manipulated and controlled variable to get a desired output.
INTRODUCTION:
A control system consists of subsystems and processes (or plants) assembled for the purpose of obtaining a desired output with desired performance, given a specified input. Figure 1 shows a control system in its simplest form, where the input represents a desired output
1 ADVANTAGES OF CONTROL SYSTEM:
With control systems we can move large equipment with precision that would otherwise be impossible. We can point huge antennas toward the farthest reaches of the universe to pick up faint radio signals, controlling these antennas by hand would be impossible. Because of control systems, elevators carry us quickly to our destination, automatically stopping at the right floor (Figure 1.3). We alone could not provide the power required for the load and the speed; motors provide the power, and control systems regulate the position and speed.
OPEN LOOP SYSTEM:
Those systems on which output has no effect on the control action are called open loop control system. In other words, in open loop control system the output is neither measured nor fed back for comparison with input .One practical example is washing machine. Soaking, washing and rinsing in the washer operate on a time basis .The machine does not measure the output signal, that is, the cleanliness of the clothes.
. SISO SYSTEM (SINGLE INPUT SINGLE OUTPUT):-
In control engineering, a single-input and single-output (SISO) system is a simple single variable control system with one input and one output. In radio it is the use of only one antenna both in the transmitter and receiver.
MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) SYSTEM:
MIMO control system is a Manipulated Input Manipulated Output system. In this type of system more than one controlled variables are applied into the process and get more than one output. The main difference between a scalar (SISO) system and a MIMO system is the presence of directions. Directions are relevant for vectors and matrices, but not for scalars. In many practical control problems typically a number of process variables which must be controlled and number of variables which can be manipulated, these problems are referred to as MIMO System. The application of MIMO system is inverted pendulum, aircraft control, and four tank controls
. CONCLUSION
In this project we have considered control problems with multiple inputs (manipulated variable) and multiple outputs (controlled variable) using a set of single-loop controllers (multiloop control). Such MIMO control problems are more difficult than SISO control problems due to the presence of process interactions. They produce undesirable control loop interactions for multiloop control. If these interactions are unacceptable, then different model-based multivariable control strategies are taken. One such is the decoupling method which is used to reduce the control loop interactions.
In MIMO system another problem is that on changing the input variable (manipulated variable) output variable (controlled variable) also changes. So relative gain array (RGA) is used for pairing the manipulated and controlled variable to get a desired output
[attachment=66537]
1. ABSRACT
In this paper, some information about the MIMO system, its transfer functions and block diagram is given. In addition, problems related to MIMO systems such as process interactions are presented. Also different strategies such as decoupling method, to reduce these control interactions are presented. Finally, relative gain array (RGA) is applied here for pairing of manipulated and controlled variable to get a desired output.
INTRODUCTION:
A control system consists of subsystems and processes (or plants) assembled for the purpose of obtaining a desired output with desired performance, given a specified input. Figure 1 shows a control system in its simplest form, where the input represents a desired output
1 ADVANTAGES OF CONTROL SYSTEM:
With control systems we can move large equipment with precision that would otherwise be impossible. We can point huge antennas toward the farthest reaches of the universe to pick up faint radio signals, controlling these antennas by hand would be impossible. Because of control systems, elevators carry us quickly to our destination, automatically stopping at the right floor (Figure 1.3). We alone could not provide the power required for the load and the speed; motors provide the power, and control systems regulate the position and speed.
OPEN LOOP SYSTEM:
Those systems on which output has no effect on the control action are called open loop control system. In other words, in open loop control system the output is neither measured nor fed back for comparison with input .One practical example is washing machine. Soaking, washing and rinsing in the washer operate on a time basis .The machine does not measure the output signal, that is, the cleanliness of the clothes.
. SISO SYSTEM (SINGLE INPUT SINGLE OUTPUT):-
In control engineering, a single-input and single-output (SISO) system is a simple single variable control system with one input and one output. In radio it is the use of only one antenna both in the transmitter and receiver.
MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) SYSTEM:
MIMO control system is a Manipulated Input Manipulated Output system. In this type of system more than one controlled variables are applied into the process and get more than one output. The main difference between a scalar (SISO) system and a MIMO system is the presence of directions. Directions are relevant for vectors and matrices, but not for scalars. In many practical control problems typically a number of process variables which must be controlled and number of variables which can be manipulated, these problems are referred to as MIMO System. The application of MIMO system is inverted pendulum, aircraft control, and four tank controls
. CONCLUSION
In this project we have considered control problems with multiple inputs (manipulated variable) and multiple outputs (controlled variable) using a set of single-loop controllers (multiloop control). Such MIMO control problems are more difficult than SISO control problems due to the presence of process interactions. They produce undesirable control loop interactions for multiloop control. If these interactions are unacceptable, then different model-based multivariable control strategies are taken. One such is the decoupling method which is used to reduce the control loop interactions.
In MIMO system another problem is that on changing the input variable (manipulated variable) output variable (controlled variable) also changes. So relative gain array (RGA) is used for pairing the manipulated and controlled variable to get a desired output