A global manufacturer of self-contained drill rigs uses the AccuRange 1000 laser distance sensor to automatically gage the depth of drilled holes. Their drill rigs are equipped with powerful down-the-hole hammers for high-capacity rock drilling in quarries, opencast mines and construction projects. The operator, sitting in a climate-controlled cabin, can know the exact hole depth on a digital console display.
The AR1000 has a nearly concentric optics path to measure down narrow holes. The range is up to 30 meters and the sensor will hold 2 mm of accuracy. Contact Acuity for more information.
Bridge Cranes Integrate Laser Distance Sensors at Steel Mills
Steel mills producing large coils of sheet stock store their inventory on the floors of huge warehouses. The large, heavy coils are picked and placed using overhead cranes, often referred to as bridge cranes. These cranes ride the length of the building along two, parallel rails. A hoist moves on the trolley and lowers a hook or other mechanical grabber to move objects. Operators control the crane’s movement via an overhead control cabin or by remote-control from on manufacturing floor.
Modern factories automate the pick and place of their inventory in 3D space by equipping their overhead cranes with multiple laser distance sensors. This automates the gross movements of the crane and minimizes the time to locate and move a particular piece of inventory. A common application is in steel mills, where building lengths often exceed 250 meters. The AccuRange 3000 sensor measures the position of the crane’s trolley along these longest stretches. Side-to-side position and the hoist’s vertical position are accurately monitored by AccuRange 1000 laser distance sensors. These models are well-suited for industrial environments and interface directly with system PLC’s using analog and serial outputs. Today’s mills retrofit manual-control cranes with automation systems employing laser positioning sensors.
Acuity manufactures and sells the AccuRange™ brand of laser rangefinders, which use time-of-flight measurement principles to detect a target’s position or displacement. The device models offer a variety of ranges, accuracies and speeds to suit a variety of industrial automation projects.
For more information about this or similar application, contact Acuity.
Demonstrating the capabilities of the new AccuProfile 820 Laser Scanner at the recent Quality Expo (Chicago), operators scanned an individual car key to produce an elevation map. The AP820 laser scanner emits a laser line onto
a surface or object. The image of this line is viewed by a high-accuracy CCD array. Height positions are calculated across this line and transmitted over an Ethernet line to a PC computer. The scanner is moved relative to the key on a small stage. The linear encoder position of the stage is tracked directly by the scanner head and included in the data stream. For more information, contact Acuity.
In 2006, the City of Minneapolis commissioned a permanent public artwork at the Minneapolis Public Library. Built into the structure of the two glass elevator cabs in Library Hall, “Four Stories” displays the titles of recently checked-out books in large, illuminated text as the elevators move between floors.
The design integrators selected the Acuity laser rangefinders to monitor the position of the elevator and hence control the scroll position of the illuminated text. The laser rangefinders were installed in base of the elevator shaft and aimed upward to a target affixed to the bottom of the elevator cart. Sampling at 100 Hz, the positional data was used in the software controlling the visual display. For more information, contact Acuity.
In this application, engineers tested the Acuity AP620-7 laser line sensor to make dimensional profiles of a small polymer part used in an industrial applications. Currently, the company uses calipers and comparators to measure this part. The area to be measured is a diameter at the circumferential “shoulder” formed by the floor of the part and an interior wall. Proper detection of the joint between the 30° wall and the horizontal surface was very important. Additionally, it was critical to align the laser line with the diameter of the circular part and not a chord. Any misalignment would result in a shorter diameter measurement. Engineers suggested scanning the part as it passed beneath the scan line and then capturing several cross-sectional frames. Software algorithms could be used to determine the maximum dimension of all collected and this number would be the diameter.
The size and shape of the part presented several challenges for using a line sensor. The small part had rather tiny features and that is why engineers chose the most accurate model of Acuity laser line sensor because it could resolve the tiny features of the part. That the area of interest was located within the cup-shaped part also presented challenges for applying the line sensor which relies on triangulation measurement principles. Although it was simple to project the laser line across the target, the height of the part’s walls would block the view by the detector. This is why simple laser triangulation sensors can not be used to measure down narrow bore holes, tubes, etc. The laser may reach the target, but the detector can’t see because the height of the walls occlude its view. To overcome this occlusion, the laser line sensor was deliberately tilted so that there was an unobstructed path for both the emitted and reflected beams.
The engineers concluded that the Acuity line sensor was a viable sensor solution for measuring such an intricate part. For more information, please contact Acuity.
A global manufacturer of steel pipes, tubes and rods maintains plants around the world that use the latest in factory automation technology. Engineers from a plant in Brazil wish to improve the fabrication processes of welded steel pipe that is used in the oil and gas indstry. Their product is formed in a multi-step bending process to steel sheet stock.
In the first step of the pipe fabrication process, a large, 12-m long carbon steel sheet is fed into a press which bends both edges with a slight radius of curvature. Precision molds sandwich the material at high pressure to introduce the appropriate bend. The system bends 3-m sections of steel at a time and a conveyor advances the material through the process until the full length of sheet has been bent. The edge bend introduces a curve approximately 40 mm from the edge, leaving a straight tail at the very edge.
In subsequent steps, the steel sheet is further formed into a tube by using other presses. Only at the end, the round structure is completed by welding the original edges. The initial edge bend is critical to final gap alignment for successful welding and proper pipe dimensions and straightness.
The prior method for measuring / verifying the dimensions of the steel sheet edge was manual in nature. Line workers would use a combination of templates, “feeler gages” and a ruler to verify the radius of the bend in the metal as well as the length of the straight tail between the end of the bend and the edge of the sheet. Certainly, this method was operator dependent and subject to great variability and innaccuracy. Over time, the template becomes deformed and worn and defeats the purpose for its initial use.
Replacing the manual verification methods was the implementation of non-contact scanning technology. A 2D profile-scanning laser is installed aboave the edge and projects a wide laser line across the steel surface. As the material passes beneath the scanner, it’s dimensional shape profile is captured by the sensor’s CMOS detector array. This X Z position information is transmitted via Ehternet interface to a PC computer that hosts measurement algorithms (software) which automatically analyzes the high-speed data and calculates the radius of curvature and the length of the straigh tail of steel sheet edge. At full speed, the laser scanner captures up to 250 profiles per second.
Integrators will install pairs of laser scanners along each edge to measure the desired dimensional information and to track the edge positions to ensure that the sheet is centered along the fabrication process. Because the scanner captures both depth position and field of view, the representation of the profile is not susceptible to slight material vibrations as it is conveyed through the process by the roller bed. The video below illustrates the entire process and the implementation of the AccuProfile Scanners in this application. Contact Acuity with questions.
A manufacturer in Brazil designs and builds tanks and vessels for use in various chemical and petrochemical industries. The tanks built from carbon or stainless steels, are fabricated in sections and welded together in a final assembly. They are required to maintain strict dimensional tolerances for the pre and final assemblies. The company approached Acuity to assist in improving their dimensional measurement practices.
Manufacturers must control the dimensions of the fabricated
Current quality control tool - a wooden template the same shape as the endcap
The manufacturer currently verifies the shape and dimensions using manual methods. Operators use a tape measure to determine the diameter of the hemisphereical endcap. The resolution of this measurement technique is 1mm and the accuracy varies on the operator technique. They have no method for measuring the interior profile dimensions of the tank’s endcap. For quality verification, operators insert a large, wooden template into each vessel and attempt to assess its fit. They will look for gaps between the edge of the template and the surface of the vessel. The plywood template is subject to thermal and moisture-induced expansion and contraction. The templates require two operators.
The solution to the measurement challenge was to use a non-contact laser distance sensor to measure the interior surface of the end-cap from a central measurement axis. The rangefinder would be rotated 180°, measuring the distance from one edge, through the base and to the other edge. This would allow not only the diameter, but also the entire profile of the shape. This information could be transmitted to a computer for display and archiving.
The AR1000 laser distance sensor has a measurement resolution of 1mm and was successful in measuring all expected surfaces, including bright-ground steel, light oxidation, paint, oiled surfaces, black paint, gray paint, etc. The planned orientation of the sensor guaranteed a strong laser reflection off shiny surfaces.
Engineers use a precision scanning confocal displacement sensor to inspect the surface of a steel brake line tip for scratches and defects. They use a new white-light distance sensor from Acuity. The measurement pen aims down to the sample that is moved on a linear XY stage. The scanning station includes a turret of several confocal measurement pens, but users can order single-channel systems.
The Boeing 787 Dreamliner is the first commercial aircraft built from lightweight composite materials. Like aluminum structure wings during their development, the composite wings undergo rigorous test. Among those tests, is the “wing up-bend test” which test the mechanical integrity the wing when being displaced upwards.
On March 28, loads were applied to the test unit to replicate 150 percent of the most extreme forces the airplane is ever expected to experience while in service. The wings were flexed upward by approximately 25 feet (7.6 meters) during the test and the fuselage was pressurized to 150 percent of its maximum normal operating condition. In evaluating the success criteria for the test, Boeing specialists have been poring over the thousands of data points collected during the test to ensure that all parts of the airplane performed as expected. “The airframe performed as designed and retained the required structural integrity. These results continue to validate the design of the 787 as we move toward certification,” explained Fancher.
Hanging from the end of each wing was an Acuity AR1000 laser distance sensor, mounted on a gimbal to ensure the laser would be pointed perpendicularly to the floor as the wing bent upwards. The AR1000 read the distance from the ends of the wings to the floor. Connected to each laser was a scoreboard display, showing the distance in large numerics that could be read from anywhere in the test area. The lasers can not be seen but the white target area on the floor beneath the wing tips is visible. That was how the 7.6 meter (25 foot) wing flexure was measured, +- 2mm.
Project M is a proposed project to land an operational humanoid robot on the moon in 1000 days (M is the Roman numeral for 1000). The humanoid (called a Robonaut) will travel to the moon on a small lander fueled by green propellants, liquid methane and liquid oxygen. It will perform a precision, autonomous landing, avoiding any hazards or obstacles on the surface. Upon landing, the robot will deploy and walk on the surface performing a multitude of tasks focused on demonstrating engineering tasks such as maintenance and construction; performing science of opportunity (i.e. using existing sensors on the robot or small science instruments); and simple student experiments.
As with most autonomous vehicle projects, the NASA RR-1 Lander requires many sensors to fully control its flight. Design engineers contacted Acuity for a solution to measure the altitude of their RR-1 Lander. The AR3000 Distance Sensor was proposed to measure the real-time height of the vehicle to 300 meters above the ground at high sampling speeds. View the integration of the laser rangefinder on the vehicle at the 3:00 minute mark of the project update video.
The area to be measured is a diameter at the circumferential “shoulder” formed by the floor of the part and an interior wall. Proper detection of the joint between the 30° wall and the horizontal surface was very important. Additionally, it was critical to align the laser line with the diameter of the circular part and not a chord. Any misalignment would result in a shorter diameter measurement. Engineers suggested scanning the part as it passed beneath the scan line and then capturing several cross-sectional frames. Software algorithms could be used to determine the maximum dimension of all collected and this number would be the diameter.
In the first step of the pipe fabrication process, a large, 12-m long carbon steel sheet is fed into a press which bends both edges with a slight radius of curvature. Precision molds sandwich the material at high pressure to introduce the appropriate bend. The system bends 3-m sections of steel at a time and a conveyor advances the material through the process until the full length of sheet has been bent. The edge bend introduces a curve approximately 40 mm from the edge, leaving a straight tail at the very edge.
The prior method for measuring / verifying the dimensions of the steel sheet edge was manual in nature. Line workers would use a combination of templates, “feeler gages” and a ruler to verify the radius of the bend in the metal as well as the length of the straight tail between the end of the bend and the edge of the sheet. Certainly, this method was operator dependent and subject to great variability and innaccuracy. Over time, the template becomes deformed and worn and defeats the purpose for its initial use.
CMOS detector array. This X Z position information is transmitted via Ehternet interface to a PC computer that hosts measurement algorithms (software) which automatically analyzes the high-speed data and calculates the radius of curvature and the length of the straigh tail of steel sheet edge. At full speed, the laser scanner captures up to 250 profiles per second.
The manufacturer currently verifies the shape and dimensions using manual methods. Operators use a tape measure to determine the diameter of the hemisphereical endcap. The resolution of this measurement technique is 1mm and the accuracy varies on the operator technique. They have no method for measuring the interior profile dimensions of the tank’s endcap. For quality verification, operators insert a large, wooden template into each vessel and attempt to assess its fit. They will look for gaps between the edge of the template and the surface of the vessel. The plywood template is subject to thermal and moisture-induced expansion and contraction. The templates require two operators.
The solution to the measurement challenge was to use a non-contact laser distance sensor to measure the interior surface of the end-cap from a central measurement axis. The rangefinder would be rotated 180°, measuring the distance from one edge, through the base and to the other edge. This would allow not only the diameter, but also the entire profile of the shape. This information could be transmitted to a computer for display and archiving.
Posted on January 9th, 2012 by admin
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