Robotic Welding Laser Sensor
Dec 2010Meta Vision Systems Ltd.Request Info
EYNSHAM, England, Dec. 21, 2010 — Meta Vision Systems Ltd. has launched the Smart Laser Pilot, a seam tracking system for robotic welding. The proprietary Smart Laser Sensor (SLS) upon which the system is based provides integrating high performance image processing functionality within the sensor head itself, making it possible to simplify the overall architecture while enhancing robot interface flexibility.
SLS technology integrates a high-resolution megapixel camera, a laser stripe projector, and advanced image processing hardware and software within a compact and rugged sensor head design. Integral cooling (gas or chilled air or, optionally, water for more arduous applications), front window blow-off and an integrated weld spatter shield ensure that the sensor will survive in the most hostile of welding environments.
The SLS is mounted just ahead of the welding torch on the robot end effector and acquires data at 30 full-frame images per second. Higher frame rates are possible using a windowing function that concentrates image analysis on a defined region of interest. All image processing is done in the sensor head itself, and a tracking accuracy of ±0.1 mm is possible in both the horizontal and vertical planes with a field of view of 50 mm.
SLS features advancements that simplify set up and operation of the system and that improve performance on shiny and other difficult surfaces. This includes an automatic laser intensity control function that solves laser reflection problems that are common in applications involving variable material surface conditions.
When welding two materials together whose surfaces have been prepared differently, or when fillet welding shiny aluminum components, the laser line from a conventional sensor may appear too bright in certain areas and dull in others, causing the laser light to reflect brightly, and the vision analysis software to make poor and inaccurate measurements.
Automatic laser intensity control in the SLS rapidly varies the intensity of the laser stripe so that darker areas become brighter, and brighter areas become darker, resulting in an image of more uniform intensity along the entire length, contributing to more reliable and accurate measurements. This also simplifies the set up process, as varying surface conditions no longer need to be considered.
The Smart Laser Pilot communicates with the robot controller using an Ethernet connection. Provided with each system is a break-out board incorporating an Ethernet switch, laser safety circuitry and a 24-VDC power supply for the SLS. The break-out board allows the use of a single cable for Ethernet and power between the robot controller and the sensor.
The Ethernet switch can route the SLS signal to the robot controller or to the user's own Windows XP/Vista/7 computer running Meta Smart Laser Pilot Tools software supplied for setting up and changing system operating configurations. The laser safety circuit is incorporated as required by international regulations to manage and control how and when the SLS laser is activated.
Ease of use is enhanced via a dedicated graphical user interface touch screen device (GIO) that is housed in a protective enclosure and displays the analyzed weld joint profile and other data as processed by the SLS, providing a tool for production monitoring and problem rectification.
The GIO is implemented as an independent means to display data of interest to the user coming from the SLS head via the Ethernet interface. Ethernet also makes it easy for the sensor to be used more generally when information on the position of a feature or its surface profile is required by another application to achieve greater levels of integration.
The Smart Laser Pilot can control virtually any robot that has a real-time Ethernet interface. If a robot is not equipped with Ethernet, an optional Ethernet input/output board is available to convert the Ethernet signals and send them to the robot controller via a serial or analog/digital interface.