computer application for testing (contact and non-contact)

EMM 5704 Computer Applications in Manufacturing Systems By: Dr. Faieza Abdul AzizEMM5704 Computer Applications in Manufacturing Systems

Computer Applications in Computer Applications in Manufacturing Systems Manufacturing Systems

EMM 5704EMM 5704

Computer application in measurement Computer application for testing (contact and non-contact)Determining testing and measurement machines and software

Group 7, Section 2:Group 7, Section 2:1.1. Zaid kh Saadon Zaid kh Saadon GS40746GS407462.2. Ghassan Maan Salim GS42930 Ghassan Maan Salim GS42930 3. Omotoso Oladiran Aremu GS412843. Omotoso Oladiran Aremu GS41284

Lecturer Name: Lecturer Name: Assoc. Prof Dr. Faieza Abdul Aziz


MEASUREMENT

What is measurement?

•Defining variables/objects with numbers

•Standard units (SI units)

History

•Mesopotamia, Egypt, Indus, Elam


How To Measure

• Tools (simple, complicate)

• software

• Machines

• Sensors (various types, different application)


How Computer Systems Does the Measurement?

1. Sensor detects analog signal.

2. signal is converted from analog to digital by A/D converter.

3. Digital signal interfaces with the microcontroller/PLC/microprocessor.

4. According to the algorithm the computer is programed, a digital signal will be sent by the microcontroller.

5. Digital signal will be converted to analog signal by D/A converter.

6. Actuators will take action.


Contact V.S Non-contact Measurements

Requirements in manufacturing:1.Repeatability2. accuracy3. cost4.speed 5.process control6.Traceability7.Precision8.excellent statistical software to facilitate tightBest Choice Depends On Application!


Contact Measurements

Contact solutions are a more traditional and widely accepted technology, and come in two main varieties: stationary CMMs and portable CMMs.

Stationary CMMs

Stationary coordinate measuring machines (CMMs) are typically very large installations—gantry, bridge and horizontal systems—that are highly accurate, expensive and much slower compared to other methods. These CMMs have zero portability and the part being measured has to be ported to the CMM itself, not vice versa.

Portable CMMs

Portable CMMs (PCMMs), which typically are stationed on an arm or are observed by a tracking device, are, as the name implies, highly portable and can be moved to a part rather than the other way around as with stationary CMMs. They are manually operated, and lower accuracy than stationary CMMs, but also come at a much reduced cost. Use of portable CMMs requires a lot less training, can be used on very large parts without requiring complex set up, and it is easy to add additional portable CMMs to increase throughput.


Drawbacks with Contact Measurement

•Stationary CMMs have the disadvantage of being fixed in one place, being very slow and quite costly. But otherwise, the advantage of accuracy always needs to be considered.

•Probe compensation is the one that needs to be mostly considered. The probe is set to assume that the first part being measured is perfect, which it is not, and all compensation is based on that assumption. The measurements are offset from the centre of the probe, based on the initial assumption of perfection. The more complex the part, the more those assumptions will come into play. While this can be managed, the assumptions have to be realistic. The most accurate probe based device may still give ambiguous results on a complex form.

•Secondly, data capture is slow. Capturing 100 points can take ten minutes, but those tend to be some very valuable points.


Non-Contact MeasurementsThe noncontact solutions are a relatively new approach in a time-honored discipline. They range across laser scanners, structured light scanners and industrial CT scanners. All of them capture the “shape” of the part so that measurements can be made and analyzed using inspection software.

The advantages of noncontact scanners over contact devices include fast data collection, and more comprehensive collection of points means a clearer view of the entire part. They are (except for CT scanners) highly portable and flexible to use, with no or very few compensations for the data being collected.

Laser Scanners

Laser scanners use laser light to create the 3-D shape of the part as a point cloud. They tend to be very flexible—you can mount them to CMMs and PCMMs—and can be hand-held or mounted on tripods. Prices range from the low thousands to above $100,000, again with the advantage being greater accuracy at higher prices. Even then, laser light causes inherent measurement noise and diffusion from the laser light limits the resolution possible, and laser based systems typically have difficulties measuring highly reflective surfaces. Camera resolution is always better than laser coherence. Your use of these scanners should be made based on the available resolution of a scanner compared to your tolerance requirements on the shop floor.


Structured Light Scanners

A structured light scanner uses projected light patterns and a camera system to record the deviations of the light to record the 3-D shape of the part. Available in multiple shades of light, these scanners are usually more accurate than laser scanners, due to a markedly lower measurement noise. In addition, they can deal with shiny parts. The combined light and camera technology delivers much greater accuracy and also means much heavier datasets to deal with. They are also less flexible, needing to be mounted and calibrated on tripods or robots.

Industrial CT Scanners

CT scanners have the advantage of being able to capture both internal and external geometry, even to the point of being able to see and identify cracks and fissures in a material almost down to the atomic level if you have the right system. This kind of accuracy demands much higher prices, and CT scanners are far less mobile—you bring the part to the scanner unit. CT scanners also have limitations on what materials can be scanned so that needs to be carefully checked against requirements.

Automation Using Noncontact Devices

Noncontact systems in particular can be easily automated for constantly repetitive measurement procedures. With the right software, the measurement analysis can also be easily automated so that go/no-go reports can be quickly created to help identify a problem almost as soon as it begins.


• Robot hand is very important device in the current industry especially factories that produce big number of products.

• Pick and place application is mainly used nowadays to reduce the time of manufacturing as the robot is able to accomplish different tasks with better accuracy and eliminates human errors and gets more precise work.

Robot Hand


• Tactile sensor is primary suggestion for

robot hand to grasp an object and place it from one position to another.

• Tactile sensor is mainly used in industry now because it has proven its efficiency.

Robot Hand using Tactile Sensor


Advantage & Disadvantages of Tactile SensorAdvantages

• Fast and reliable.

• Cheaper.

• Simple (not complex).

• Easy to use.

Disadvantages

• Object position must be programed.

• Object might be damaged if it is not placed in the right position.

• Error may occur if object placed wrongly.


• Image processing is an advanced technology which use in many applications nowadays. This technology is applied in robot hand to sense the object location and to grasp it.

• This technology is much advanced because it can detect the object automatically and grasp it accurately with less time.

Robot Hand using Image Processing


Advantage & Disadvantages of Image Processing

Advantages • More accuracy.

• It can find the position of object and pick it.

• Possibility to detect object`s shape.

• More technological.

• Less error.

Disadvantages • Higher cost.

• More complex.

• Required more accurate programing.


Software for Inspection• There are several inspection software products on the market, all of which have

their own advantages and disadvantages.

• Inspection software bridges the gap between the point collection and the design requirements. Obviously, not all software is the same, and you need to be on the lookout for the ease-of-use versus training requirements. You also need to choose your software based on the capture device(s) you are using. Always require a test run of the software using one of your typical production parts, and if you have budget available go for a full pilot test of the complete system. This will allow you to make considered and well-researched decisions. Consider how you want to be given results of the measurements, as reporting types can vary across software products.


Contact-centric software

This software is targeted primarily at contact-based measurement: it typically cannot handle large datasets provided by noncontact scanning as well as products developed for the noncontact solutions. If you are certain you will only be using contact measurement, look to FARO CAM2, Hexagon PC-DMIS, Verisurf, BuildIt!, and Delcam PowerInspect, among others.


Noncontact Software

Inspection software for noncontact measurement is a wholly different experience from the traditional methods, and is aimed at the new generation of measurement. Consider if you have reference data available—normally a CAD file—for comparison purposes, which is the best solution, even though most of the products available also work without CAD reference data. Define if you might need automation, and also be on the lookout for software that has been certified by NIST for accuracy. Products include Geomagic Qualify, Rapidform XOV, Innovmetric Polyworks, and GOM Inspect.


Thank you

computer application for testing (contact and non-contact)

Engineering

computer systems

manufacturing measurement

manufacturing contact

analog signal

testing contact

digital signal interfaces

measurement machines

faieza abdul aziz