QUESTION 5

The main advantages of automation are: Increased throughput or productivity. Improved quality or increased predictability of quality. Improved robustness (consistency), of processes or product. Increased consistency of output. Reduced direct human labor costs and expenses. The main disadvantages of automation are: Security Threats/Vulnerability: An automated system may have a limited level of intelligence, and is therefore more susceptible to committing errors outside of its immediate scope of knowledge (e.g., it is typically unable to apply the rules of simple logic to general propositions). Unpredictable/excessive development costs: The research and development cost of automating a process may exceed the cost saved by the automation itself. High initial cost: The automation of a new product or plant typically requires a very large initial investment in comparison with the unit cost of the product, although the cost of automation may be spread among many products and over time.

QUESTION 4

Open-Loop Control Systems utilize a controller or control actuator to obtain the desired response Closed-Loop Control Systems utilizes feedback to compare the actual output to the desired output response. Multivariable Control System Term Used In Control System

QUESTION 3

Temperature control is a process in which change of temperature of a space (and objects collectively there within) is measured or otherwise detected, and the passage of heat energy into or out of the space is adjusted to achieve a desired average temperature. A home thermostat is an example of a closed control loop: It constantly assesses the current room temperature and controls a heater and/or air conditioner to increase or decrease the temperature according to user-defined setting(s). A simple (low-cost, cheap) thermostat merely switches the heater or air conditioner either on or off, and temporary overshoot and undershoot of the desired average temperature must be expected. A more expensive thermostat varies the amount of heat or cooling provided by the heater or cooler, depending on the difference between the required temperature (the "setpoint") and the actual temperature. This minimizes over/undershoot. This method is called Proportional control. Further enhancements using the accumulated error signal (Intergral) and the rate at which the error is changing (Derivative) are used to form more complex PID Controllers which is the form usually seen in industry.

QUESTION

QUESTION 2 Process variable - is a statistics and engineering discipline that deals with architectures, mechanisms and algorithms for maintaining the output of a specific process within a desired range. See also control theory. A servomechanism - sometimes shortened to servo, is an automatic device that uses error-sensing negative feedback to correct the performance of a mechanism.The term correctly applies only to systems where the feedback or error-correction signals help control mechanical position, speed or other parameters. For example, an automotive power window control is not a servomechanism, as there is no automatic feedback that controls position—the operator does this by observation. By contrast a car's cruise control uses closed loop feedback, which classifies it as a servomechanism. Feedback - There are many different control mechanisms that can be used, both in everyday life and in chemical engineering applications. Two broad control schemes, both of which encompass each other are feedback control and feed-forward control. Feedback control is a control mechanism that uses information from measurements to manipulate a variable to achieve the desired result. Feed-forward control, also called anticipative control, is a control mechanism that predicts the effects of measured disturbances and takes corrective action to achieve the desired result. The focus of this article is to explain application, advantages, and disadvantages of feedback control. Process set point - A preset value such as a specific speed or position that the control system is supposed to reach. Also known as the target value. Error - The difference between the SP and the PV. When errors are detected, the controller sends instructions to the control system to adjust the output to compensate. Controller and Measurement - A proportional-integral-derivative controller (PID controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems. A PID controller calculates an "error" value as the difference between a measured process variable and a desired setpoint. The controller attempts to minimize the error by adjusting the process control inputs.

Basic Principles of Pneumatics,Hydraulics and Control system

Pneumatic: A system in which gas pressure differences and their rates of change are related to gas flows, their integrals and their rates of change. Hydraulic: A mechanism operated by the resistance offered or the pressure transmitted when a liquid is forced through a small opening or tube System – An interconnection of elements and devices for a desired purpose. Control System – An interconnection of components forming a system configuration that will provide a desired response. Process – The device, plant, or system under control. The input and output relationship represents the cause-and-effect relationship of the process.