Automated Laser Scanning Using a Collaborative Robot

Automated Laser Scanning device to be the first programmable laser scanning system to enable automated 3D scanning, dimensional measurement and dimensional gagging leveraging a collaborative robot platform.


Manufacturers are increasingly integrating automated processes is commonly exemplified in the form of robots loading/unloading CNC mills, lathes and so on. In fact, recent advances in collaborative robot technology, that is, robots that can safely operate alongside without protective fencing, are opening up opportunities for shops to apply automation in new ways.
Manufacturer of a range of industrial metrology equipment, brings the collaborative robotics concept to automated part inspection and gagging with its AutoScan Collaborative Gauge, which is the first programmable laser scanning system to enable automated 3D scanning, dimensional measurement and dimensional gagging leveraging a collaborative robot platform.
The AutoScan is an alternative to conventional manual laser scanning devices in which users continuously maneuver the laser across the surface of a part like they’re “painting” it. Conversely, the programmable, collaborative robot platform enables automated part scanning routines to be performed alongside sans the safety infrastructure that’s required for conventional robots.
The system’s three primary components are the collaborative robot, Perceptron’s Helix 3D laser scanning sensor and its Vector software. The scanning sensor is mounted to the arm of the six-axis robot, which uses built-in force-sensing technology that causes it to stop its movement if it makes contact with a person (rated to the ISO 10218-1:2011 safety standard for industrial robots). The AutoScan has a robot reach radius of 1,300 mm and sensor standoff of 200 mm (larger work areas are available), offering a rigid, fixed mount or optional mobile stand to enable it to be deployed in different areas of a shop as needed.
Using value streaming and lean principles, he documented every step of the existing manufacturing process, from raw materials through machining, inspection and preparation for shipping and decided to take the approach that everything we were currently doing to make these parts was wrong. This helped to look of simply trying to improve the process we already had, we rethought our entire approach to see how could make these parts much more efficiently.image
The existing process began with receipt of barstock that would saw to size, load into the first machine tool to rough, turn one end and then set aside for batching. When a batch of parts was ready, each part would be individually loaded into additional machines for further processing, which included a polishing machine to achieve the required surface finish. Because of all of the handling in and out of machines, the parts often had to be re-polished to meet specifications that each part traveled the equivalent of one mile throughout his facility, from start to finish. The entire process required three CNC lathes, two milling operations, polishing, washing and inspections after each operation. Throughout this journey, at least 15 people touched the part during the course of two and one-half shifts. These touches included sawing and stacking barstock on pallets, machining, counting, batching, washing, inspecting and shipping. Recognizing that every touch adds cost to a part.
Looking for a turnkey solution the capability to combine machining, inspection and automation that would integrate everything from raw materials to finished parts and could be attended by a single machine operator. As a result, the company now needs only 4 minutes, 51 seconds to make (from raw stock to out the door) aluminum CNG tank end caps that previously took 39 minutes, 21 seconds to complete. Not only is this a huge time savings, it also frees up considerable floor space that was occupied by the additional 14 people, tools and working space that the former system required.
The automation system designed consists of one FANUC R-2000iB/165F six-axis industrial robot positioned in the center of three Okuma LB-3000EX-MY lathes arranged in a semi-circle. A floor-mounted pallet locator positions a pallet holding workpieces delivered by a lift truck. The family of parts consists of 17 distinct end caps made from blanks that range in size from 4 inches in diameter by 3 inches in length, to 8 inches in diameter by 8 inches in length.
Rethinking the process from raw material onward led to replacing the raw barstock, which Northeast Tool originally sawed into part lengths, with precut bars bearing part identification codes. The robot employs an end-of-arm tooling-mounted iRVision system to confirm the part identification codes and locate the parts for pickup. An end-of-arm, three-jaw, OD gripper system grips the workpiece on the outside shank diameter for loading and unloading the lathes as well as for placing and removing parts for post-process inspection on a coordinate measuring machine (CMM).
All programs for the 17-part numbers reside in the machine tool and are called up by the automation system based on the next part to be processed. In operation, the robot locates the part by using the vision system to identify the 2D bar code. It then loads the part into the first machine tool that performs rough machining, and then moves it from the first machine to the second Okuma lathe, which machines the front side. The third lathe performs milling and second turning operations. Between operations, the robot flips parts as necessary based on the part program. Post machining, the robot unloads the part from the third lathe and places it on a CMM for inspection. Data from the CMM measurements are fed back into the machine tools to enable automatic tool offsets. In addition to the time and cost savings, automation is helping the company accelerate growth strategies and In fact, it is ready to more than double the existing facility to about 70,000 square feet. This expansion will enable Tool to further automate the plant and provide much needed space for material storage. It will also help to improve shipping and receiving functions. The goal is to make every aspect of the business more efficient while moving into new markets. Helix laser scanner uses MEMS (micro-electro-mechanical systems) solid state optical technology, and all workpiece feature scanning is performed with the multi-axis robot in a static position and the robot is used purely as a positioning device for the end-of-arm laser scanner. That way, potential measurement errors due to robot acceleration and possible robot structure deflection, for instance, aren’t introduced into the scanning process.image
The Helix scanning sensor uses a Class 2M laser to capture a 3D digital representation of the part and reports complex form and surface deviations relative to the part’s CAD model, together with discrete information for critical features such as holes, slots and studs. Self-teach capability enables robot movement to be programmed manually by moving the robot to each scanning position. All robot moves are then automatically written to the part inspection program to enable subsequent parts to be inspected automatically. The software features comprehensive geometric dimensioning and tolerancing (GD&T) capabilities as well as a self-teaching “Autosolve” feature extraction based on feature type for measurement of holes and studs, for example. As many as 200 scan lines per feature can be programmed with automatic feature extraction from the generated point cloud dataset, enabling multiple features to be inspected with the robot in a static mode. The configurable laser line density enables scan line intervals to be defined as small as 0.1 mm, and laser line length and orientation of ±45 degrees is said to be easily programmed. Vector analysis and reporting software offers real-time status monitoring, showing immediate results via a measurement monitor, tolerance limit alarms and a one-shot view of part trending. It also offers an SPC reporting package with historical database for traceability, data analysis for process improvements and remote access to inspection results.