CheatSheet - Click to edit Master subtitle style CH 4...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Click to edit Master subtitle style 9/13/11
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
9/13/11 H – 4 Automation is the technology by which a process or procedure is accomplished without human assistance. It is implemented using a program of instructions combined with a control system that executes the instructions. Three basic lements of an automated system : Power to accomplish the process and operate the system.A program of instructions to direct the processA control system to actuate the instructions. Power for the process:To rive the process itself. To load and unload the work unit. Material transport between operations. Power to automation: Controller unit, Power to actuate the control signals, Data acquisition and informatio n rocessing of instructions : set of commands that specify the sequence of steps in the work cycle and the details of each step. Work cycle program: typical sequence of steps is: Load the part into the roduction machine, Perform the process, Unload the part. Process parameter : are inputs to the process, such as temperature setting of a furnace. Decision making in the programmed work cycle: Operation nteraction : the controller unit may require input data from a human operator in order to function. Different part or product styles processed by the system : the automated system is programmed to perform different ork cycles on different part or product styles. Variations in the starting work uni ts: in many manufacturing operations the starting work units are not consistent. Features of work cycle program: No. of steps in he work cycle, Manual participation on the work cycle, Process parameters, Operation interaction, Variations in part or product styles, Variations in starting work units. Control system: controls in an utomated system can be either closed loop or open loop . Closed loop control system : it is also known as feedback control system. One in which the output variable is compared with an input parameter, and ny difference between the two is used to drive the output into agreement with the input. It consists of six basic elements: Input parameter, Process, Actuator, Output variable, Feedback sensor, Controller. nput parameter : often referred to as the set point, represents the desired value of the output. Process : is the operation or function being controlled. Output variables : that is being controlled in the loop eedback sensors : is used to measure the output variable and close the loop between input and output. It performs with the input and makes the required adjustment in the process to reduce the difference etween them. Actuato r: the hardware device that physically carryout the control actions, such as an electric motor or a flow value. Controller : compares the output with the input and makes the required djustment in the process to reduce the difference between them . Open loop control system : operates without the feedback loop. This system are appropriate when the following conditions apply: The actions erformed by the control system are simple, The actuating function in very reliable, Any reaction forces opposing the actuation are small enough to have no effect on the actuation
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/11/2011 for the course INDE 3333 taught by Professor Sontag during the Fall '11 term at University of Houston.

Page1 / 2

CheatSheet - Click to edit Master subtitle style CH 4...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online