 Hello, I am Milka Jagle, working as assistant professor in Department of Mechanical Engineering Virtual Institute of Technology, Solarboard. Today, we are going to learn about control systems, water control systems and what are different types of control systems, learning outcome. At the end of this session, students will be acquainted with basics of control system and identify various control systems. So, these are the contents of today. So, let us see what is system? A system is a combination or an arrangement of different physical components which act together as an entire unit to achieve certain objective. It can also be defined as an interconnection of elements and devices for a desired purpose. So, let us see what is control system? Control system consists of interconnected components designed to achieve a desired purpose. Modern control engineering practice includes the use of control systems for improving manufacturing process. Control systems are integral part of modern industrialization, computerized control systems, transportation systems, power systems, temperature limiting systems and robotics. Let us define control system. As we have discussed earlier, control system is an arrangement of different physical components in such a manner so as to regulate, direct or command itself or some other system. It can also be defined as it is an interconnection of components forming a system configuration that will provide a desired system response. So, let us see what is a process? A component or a process to be controlled can be represented by a block diagram. The input-output relationship represents the cause and effect relationship of the process. Have a look on figure number one that is input which is provided to the process or a plant. So, let us see the generalized control system. The generalized control system consists of controller, actuator, sensor, process or a plant, reference input and reference output. A controller is used to control the system, the actuator converts the control signal into power signal, process or a plant is itself to be controlled and sensor is used for the measurement purpose. So, let us see the components, plant that is to be controlled, actuators converts control signal into power signal, sensors provides measurement of a system output, controller controls the plant or a process, input, input variable is referred as reference input whereas output variable is referred as controlled output, disturbance it is a signal which affects the value of output. So, now I want you to pause the video for few second and think what is the need or what is the purpose of control system? Just write down the need of control system. So, let us see the need of control system. Safety. The plant or process must be safe to operate, more the complex or the danger the plant or process greater is the need of automatic control and safeguard protocol. Second one, stability. The plant or process should work steadily, predictably and repeatably without fluctuations or unplanned shutdowns, accuracy. This is the primary requirement in factories and buildings to prevent spoilage, increase quality and production rates and to maintain the comfort. These are the fundamentals of economic efficiency. So, these three factors plays an important role which says the need of control systems. So, let us see the types of control system first one that is open look control system. An open look control system utilizes a controller or control actuator to obtain the desired response. Just observe the figure number three which shows the open look control system, it is a system without feedback, actuating device gives the signal to the process and the process leads to the output. An open loop system is a system without feedback, it is a system in which input signal is independent on the output signal. Close loop control system utilizes feedback to compare the actual output to the desired output response. A system in which input signal is dependent on the output signal. Figure number four shows the closed loop system, here the measurement device that is feedback is given to the comparison that is feedback is examined and then the controlled input is given to the controller. A closed loop system uses a measurement of the output and the feedback of the signal to compare it with the desired output that is reference or command. So, let us see what is feedback. Feedback is a key tool that can be used to modify the behavior of a system and feedback compares the output signal with input signal in order to generate error signal to achieve or generate the desired output. So, let us see the next type of control system that is multivariable control system. It is a system with multiple inputs and multiple outputs. Due to the increasing complexity of the system and the control and the interest in achieving optimal performance, the system becomes more complex and the interrelationship of many control variable must be considered. So, figure number six shows multivariable control systems. Here a controller receives multiple inputs and multiple outputs are given as the output. Control systems have significantly increased through advances in computer technology and development of new materials which provide unique opportunities for highly efficient actuation and sensing thereby reducing energy losses and environmental problems. Following are the applications of control system, biological propulsion, locomotion, robotics, material handling, biomedical, surgical, aeronautics and defense and space industries. These are the references.