Measuring distances, areas, co-ordinates and critical dimensions to assess conformance to specification and tolerance. From simple dimensional verification through to metrology level gauging.
Machine vision measuring is used to autonomously confirm the dimensional accuracy of components, parts, and sub-assemblies without the need for operator intervention. Machine vision has the advantage of being non-contact, which means it does not contaminate or damage the part being inspected. IVS machine vision systems can also measure object features down to the micron level, providing a non-conventional solution.
Faster measurements, reducing inspection time, eliminating human-error, without marking your products.
IVS measurement systems are calibrated to tracebable national standards. Configurable from dimensional verification through to micron level, metrology grade measurements.
We tailor reports to your requirements, from spreadsheets to SQL databases. Validation is also made simple with Type 1 and R&R gauge studies and reports.
Historically, the dimensions of parts and products were measured with gauges or inspection jigs to ensure that there is no variation in measurement accuracy. Gauging using measurement jigs inevitably involved errors due to individual differences among workers and overall measurement conditions. Also, these old methods do not show or report accurate measurement values which can be reviewed, saved and used to conform to process performance.
These methods all share the problem of requiring manual operation which is both time consuming and expensive to perform. With the increased use of industrial automation and quality inspection needed in these environments, vision systems performing high precision automated measurements has become a pre-requisite for the modern factory production line.
With IVS® machine vision solutions, dimensions can be taken from captured images at high speed. It is simple to measure the dimensions of multiple areas of parts and products based on this information and judge whether they are within measured tolerances. Another advantage is that manufacturers can measure parts and save all data for statistical process control (SPC).
Real-time calibration provides high-performance measuring which is easy and quick to set up, while edge detection and high-definition contour analysis provides exact matching and measuring capability. Automatic data recording, image saving and inspection reporting are included with all IVS® vision systems, providing brand and warranty protection against customer complaints or costly recalls. All data can be saved to factory information systems, SQL databases or directly on the vision system.
IVS® provides sub-pixel precision vision systems for reliable measurement and dimensionally accurate inspection. From checking simple geometrical tolerances to micron-level detection, customers can be confident that our gauging and measuring vision solutions provide robust and repeatable results. Powerful gauging wizards are incorporated into our vision systems, enabling customers to make sophisticated measurements to sub-pixel accuracy at very high speeds.
The three most crucial requirements of any gauging solution are repeatability, accuracy and precision. The variance of repeated measurements, or repeatability, refers to how near the measurements are to each other. The accuracy of the measurements refers to how close they are to the genuine value. The number of digits that can be read from the measurement gauge is known as precision. IVS® carefully select the equipment required to perform the gauging task based upon these three requirements.
In precise gauging applications, such as measuring the thickness of a medical device needle, telecentric optics, telecentric light arrays and high-definition cameras can be utilised. Telecentric optics keep the magnification of the imaged object constant regardless of depth.
If the measurements are not required to have micron level accuracy, such as measuring the tabs of a catalytic converter support mat, then standard machine vision optics can be used.
IVS® vision systems can be calibrated before they perform measurements. Calibration is as simple as telling the machine that a unit of measure equals a certain number of pixels. Therefore, ensuring accurate measurements are computed. This will typically be carried out on an artifact with known measurement values that is traceable back to national Standardards.
Industrial vision gauging is used by manufacturers for a variety of reasons. One of the most important factors is speed. Because it’s impossible to keep up with high-throughput manufacturing lines with manual touch gauging, measurements are usually carried out on an audit basis. Machine vision systems, on the other hand, can keep up with the quickest production lines, make thousands of measurements per minute, and are built for 100% inspection in-line.
Because it does not involve physical touch, industrial vision gauging prevents damage to parts and eliminates maintenance associated with wear and tear on mechanical gauges. Finally, vision systems allow for the measuring of parts that would otherwise be near impossible to measure using standard methods.
The use of a jig to examine dimensions does not provide precise measurement data. It simply determines if the dimension falls within the tolerance range. Dimension inspection with image processing produces not only pass/fail judgements, but also numerical data for the specific dimensions of various parts, which may be recorded and maintained simply. IVS can create custom csv files or SQL databases for data logging, combining this with traceability image saving the customer has a complete production record.
Custom reports containing measurement data can also be created in excel or pdf formats. Where CFR 21 is concerned, the reports can be printed in real time and no data saved on the industrial vision controller.
It is usually less important to ensure that individual measurements are within narrow tolerances when using gauging as an assembly verification method, than it is to verify that certain relationships between items are confirmed.
Assembly verification using gauging: In this sort of application, the validity of objects is determined by the gauging findings; that is, relationships between items, such as distances, angles, circle similarity, and so on, are significant in addition to basic properties. It’s frequently more necessary to consider how the measurements relate to reference objects than it is to achieve high accuracy.
An image is evaluated by position and brightness of pixels. For example, a point with an actual brightness of 39.9% of the camera’s full range will receive the grey level 102, although the ‘real’ grey level would be 101.745.
A vertical edge at 63.3 in real life will be transferred to pixel coordinate 63. Pixel 63 will be dark already if it has a dark edge.
As you can see there is some information loss by the camera’s quantisation. Part of this information can be regained, because the nearby pixels of a camera’s sensor are interdependent.
Because a pixel’s excess brightness brightens nearby pixels, the black edge will not result in a sudden change in grey level at pixel 63; instead, pixel 63 will be slightly darker than pixel 62, while pixel 64 will achieve the final grey level for the interior of the dark item.
The original information can be restored by interpolating between neighbouring grey levels, as seen in the image on the right. This allows for edge localisation with a precision of up to one-tenth of a pixel, so long as proper lighting and image capture conditions are available.