5.1 THE BASICS OF AUTOMATION MECHANISATION VS AUTOMATION 1 The words mechanisation and automation are commonly used to refer to tasks carried out by machines. However, while is simply the substitution of human workers with machines, is the use of self-regulating machines to perform operations of different kinds, involving the application of technology, programmes or processes to jobs and activities with very little human intervention. Automated systems employ machines which can be programmed for a specific task and re-programmed for a different one, following a predetermined sequence of operations and employing specialised equipment and devices which carry out and control the manufacturing process. mechanisation automation fulfil MORE The word is derived from a Greek word meaning "self-acting". 1 automation Automation processes Automation processes are developed in a series of steps, which are very similar even for different automated systems, and which require very little human intervention. Every automation process starts with an . The input can be given by a switch or a sensor which can detect objects, signals or physical quantities. input The input is sent to a (Programmable Logic Controller), the brain of the automated system, containing the programmes that make the system carry out specific tasks. PLC According to the programmes, the automated system generates an , which activates devices such as motors or other kinds of machinery. output The automated process continues as a until it receives a stop signal from a switch or a sensor. cycle Self-regulation of automated systems Automated systems can regulate themselves by monitoring their own working process, detecting and correcting errors. This is obtained through a which allows the machine to monitor its output and adjust its operations in a series of actions. feedback loop First of all, an automated system gets data from the environment through sensors , i.e., dimensions, weight, or temperature, and measures it. 2 The measured quantities are evaluated: the data collected by the sensors is compared by the controller with the correct values programmed in it. If there are differences between the values given and those expected, adjustments are made to make the output of the process correspond to the programmed values. MORE Examples of sensors in an automated system are photoelectric cells, distance sensors, thermocouples and sensors. 2 strain