GENERAL KNOWLEDGE OF AUTOMATION Automation is used to describe a wide variety of systems in which there is a significant substitution of mechanical, electrical, or computerized action for human effort and intelligence. In general usage, automation can be defined as a technology concerned with performing a process by means of programmed commands combined with automatic feedback control to ensure proper execution of the instructions. The resulting system is capable of operating without human intervention.
Vision system application ; ROBOTIC AND ITS APPLICATIONS Part identification – vision system store data Type of difference vision Robots: for different parts in memory and use the data sensor =Robots are very good for repetitive to distinguish between parts as they enter the proximity 1.Two major -electronic tasks such as moving and positioning work cell. parts between devices and products. Fast Part location – vision technology allows the sensor types of sensors that and accurate. automation system to locate randomly placed proximity indicate the =3 types of robots: Electric Robots, parts entering the work cell. detectors are presence of an Pneumatic Robots and Hydraulic Part orientation – vision system supplies the (i) inductive object without Robots. orientation information and the data are used and (ii) making =Electric robot – very versatile, often to drive the robot gripper into the correct capacitive physical used for painting and welding because it orientation for part pickup. is fast & accurate. More expensive than contact Part inspection – vision system are used to pneumatic robot. check parts for dimensional accuracy Ultrasonic 1. electrostatic =Pneumatic robot – good for simple -Ultrasonic (e.g.diameter of a part) and geometrical Sensor – uses positioning tasks, it is inexpensive sensors use a integrity (e.g. number of holes). capacitive compare to electric robot and pneumatic high- Part finding – the system uses two or more effects. It has robot. But the usage is very limited in cameras to measure the X, Y, Z location of frequency some ways. longer ranges the part. This technique also used to measure oscillators to =Hydraulic robot – good for heavy and wider and calculate the cross- sectional area of parts. generate applications, fast and can move bandwidth, but smoothly. Also good for dangerous Vision System Operation: frequencies -Vision systems look at contrast to make is more applications. above 20KHz. decisions. A camera used to capture the image sensitive to Robot Integration: and the it will be analyzed by the computer. factors such as =Two methods to control the robot: 1) -The vision processing board looks at each humidity Using teach pendant 2) Using special pixel to determine its brightness level. (Gray Hall-Effect programmed language Level) 1.This sensor is -This sensor =Robots have digital inputs and digital sensor -The computer then will look at all areas of a flat detects the outputs which are easily connected to the object and assign brightness levels, which rectangular presence of a control devices. (e.g. PLCs, Computer) represent contrast to each. piece of P-type magnetic field =Most robots cells wait for an input to Type of Vision System: tell robot what to do, it then forms a task semiconductor Binary system – lowest in cost, easiest to use and sends back an output signal to a cell & do basic visual inspection called a Hall controller. Gray scale imaging – using 256 levels of generator – =The exchanges process of input and black and white, more accurate than binary made from outputs between devices is called system, expensive than binary & sometimes indium “Handshaking” has longer processing times. arsenide (In THEORY OF BOURDON Color processing – uses information from TUBE,SPRING,BELLOWS,DIAPHRAGM) As) red, blue and green parts of the color =The Bourdon tube is a hollow tube Photoelectric with an elliptical cross section. When a spectrum to detect and differentiate shades of 1.Emitters will -Optical color relevant (e.g. in food industry and Sensor pressure difference exists between the produce light sensors pharmaceutical), more expensive than the first inside and outside, the tube tends to beams in the require both a two types, but they offer unique advantages. straighten out and the end moves. The visible and light source movement is usually coupled to a needle GENERAL KNOWLEDGE OF AUTOMATION invisible (emitter) and on a dial to make a complete gauge. -Automation is used to describe a wide variety spectrums detector =The pressure acts directly on the piston of systems in which there is a significant using LED and and compresses the spring. The position substitution of mechanical, electrical, or laser diodes of the piston is directly related to the computerized action for human effort and Fiber -Fiber optics pressure. A window in the outer case intelligence. -The basic allows the pressure to be indicated. This Optics are transparent type is usually used in hydraulics where -In general usage, automation can be defined structure of an as a technology concerned with performing a Sensors stands of glass the ability to withstand shock, vibration optical fiber process by means of programmed commands or plastic that and sudden (OF) consists combined with automatic feedback control to transfer light pressure changes is needed (shock proof of three ensure proper execution of the instructions. to and from gauge). different = If the bellows is encapsulated inside an The resulting system is capable of operating such locations without human intervention. layers: the outer container, then the movement is -Automated System: a collection of devices core, the proportional to the working together to accomplish tasks or cladding and difference between the pressure on the produce a product. (e.g.. an Automobile and the coating or inside and outside. Bellows and single Home burglar alarm system) jacket . capsules are used in many instruments. Purpose of Automation They are very useful for measuring small -To increase productivity and reducing costs. pressures. -To Increase quality and flexibility. =These are similar in principle to the -Replace human intervention for hazardous capsule but the diaphragm is usually operations ) very thin and perhaps made of rubber. -Increased emphasis on flexibility and The diaphragm expands when very small convertibility in the manufacturing process. pressures are applied. The movement is transmitted to a pointer on a dial through a fine mechanical linkage THEORY AND APPLICATION SIGNAL CONDITIONING AND OF,ULTRASONIC,HALL-EFFECT PROCESSING: PROXIMITING A basic instrument system consists of three -=Unshielded sensors do not have this metal elements: band, therefore they can be side sensitive. =Shielded construction includes a metal band i SENSOR or INPUT DEVICE which surrounds the ferrite core and coil ii SIGNAL PROCESSOR arrangement. It will direct the electromagnetic iii RECEIVER or OUTPUT DEVICE field to the front of the sensor. 1.Oscillating signal from oscillator stage is Figure1: Block diagram of basic instrument fed into the demodulation section. The system demodulator is a filtered rectifier which converts the AC signal into a DC voltage level. Capacitive sensor Application: =As an object approaches, the oscillator begins to oscillate. The closer the object the faster oscillation become. =This situation will cause the Schmitt trigger to switch to its higher voltage level. Most modern analogue equipment works on the =The positive potential forward biases the following standard signal ranges. base emitter junction of the NPN transistor, =Electric (4 to 20 mA) causing it to turn ON. =Pneumatic (0.2 to 1.0 bar) Ultrasonic Sensor 1. has 2 unit - transmitter unit -receiver unit Application: =The sensor consists of a transmitting and receiving devices. =The basic principle for this sensor is that if sound transmitted through air, a portion of it will be reflected. =The reflected signal is called an “echo”. Hall-Effect sensor =When a power source supplies a constant current to the sensor, positively charged carriers flow uniformly through the material when a magnetic field is not present =At this condition, the voltage at the output is zero =When an electromagnet or a permanent magnet is present near the semiconductor material, the magnetic field from the electromagnet target will deflect the positive charged carriers to one side of the semiconductor material by an effect called Lorentz force Block diagram of Capacitive Proximity sensor
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