SVS-Vistek has collaborated with Swiss robot maker Asyril to improve the performance of assembly robots using sophisticated image processing systems, innovative ideas and industrial cameras. Stefan Waizmann, technical marketing engineer at SVS-Vistek, explains more.
At almost every automation trade fair in recent years, the attempts of various companies to realise the famous “reach into the box”, i.e. the gripping of unordered components by a robot, can be seen. Despite enormous progress in the field of robotics and image processing, this task still poses a great challenge.
The reasons for this are obvious: Before a robot can grip a component, an image processing system must first reliably recognize it, calculate its orientation, and then communicate the position and orientation of the gripping points to the robot. In conventional technology, this is still a slow, multi-stage process (recognition, gripping, correct depositing, gripping with correct orientation). If the components to be gripped are chaotically mixed up and partially concealed, the safe and fast gripping of individual parts often becomes a complex and slow process.
Asyril has taken a new approach to this task, which is frequently encountered in industry. The Swiss company builds fast, highly efficient feeding systems for ‘pick and place’ robots using a trick that is simple at first glance but very innovative in detail. The bulk material objects lying next to and on top of each other in a box are guided via a feeding hopper to a vibration platform, where they are separated and placed in a position that allows easy access by the robot.
Vibration in three axes
The basic idea goes far beyond conventional mechanical systems such as vibrating pots, explains Asyril product manager Aymeric Simonin: “The special feature of our high-performance feeding systems is that the results of an integrated image processing system are used to control the vibrations of the platform in such a way that the objects are separated.
“The specialized vision system delivers the necessary data almost in real time, ensuring that the parts are isolated in a controlled manner and brought into a gripping position that is optimal for the robot. After separation by “intelligent vibrations”, the image processing system communicates the data of the position and orientation of the components to be optimally gripped to the ‘pick and place’ robot, for which access is child’s play. In order to optimize the speed of object detection, the system sends the information about the first detected, well-placed components to the robot before the entire image is evaluated.”
The technical basis for this procedure is a flexible feeder called Asycube. Asyril developed this innovative, patent-protected 3-axis vibration technology itself, manufactures it in-house and uses it in its high-performance feeding systems. The high-quality actuators cause a vibration platform to vibrate, which can be controlled in terms of strength, frequency and duration, allowing the components to move quickly and accurately on the vibration platform.
Economical image processing
The second core element of Asyril’s flexible feeder solution is the integrated SmartSight vision system, which assesses the quality of the separation and determines the positions of the next optimally positioned parts with the knowledge of the robot gripper’s capabilities.
“An economical design was also important to us for this part of the overall system,” stresses Simonin. Asyril opted for several camera models from the EXO series with resolutions between 1.6 and 12 megapixels, after initial systems based on ECO cameras from SVS-Vistek, which, in addition to image acquisition, also take over control of the light and thus make an additional strobe controller obsolete.
“This enabled us to reduce the hardware costs for the entire system and to operate incident and transmitted light with short flash times directly from the camera’s power outputs,” says Simonin, describing the image processing setup. The timings for light and exposure come directly from the camera, which controls the electrical processes and the integrated four-channel LED driver with its sequencer. Light, sequencer and camera are controlled via a single programming interface.
“Our technology is very flexible and is suitable for loose parts and components of all geometries with sizes ranging from less than 0.1 mm to 150 mm,” says Simonin. The feeders used enable extremely gentle feeding of parts, which can be a decisive criterion depending on the application.
Thanks to their modular design, Asycube feeders can be flexibly and quickly adapted to the properties of the objects. In addition to easily exchangeable hardware modules, this configuration flexibility is also ensured by easy-to-use, PC-based image processing.
“When switching to other products, the advantages of a programmable feeder become particularly obvious: Configuration is carried out very quickly via software and saves expensive hardware set-up times. This is a big advantage, especially in markets with very short product life cycles or small series,” added Simonin.
For the realisation of the SmartSight vision system integrated into the Asycube feeders, Asyril works together with Fabrimex from Volketswil, Switzerland, who, as partners of SVS-Vistek, complete their innovative camera technology to tailor-made optical solutions from a single source.
The development of Asyril enables robots to access individual parts or bulk materials more quickly, which leads to considerable increases in efficiency. “We are rooted in the Swiss watch industry with its high demands, but the advantages of our technology have now also proven themselves in many other markets such as the automotive, medical and electronics industries,” says a delighted Simonin.
“With Asycube SmartSight, we can offer users a fast alternative to the still slow, complex grip on the box and thus increase the productivity of the robots used.
The advantages of material feeding through the innovative Asycube solutions are now also paying off in other ways: At the MOTEK trade fair in Stuttgart at the end of 2018, Asyril was awarded a prize in the “Components for Handling and Assembly” category.
The vibration platform of the Asycube feeders enables controlled movement and separation of bulk material objects. (Image source: Asyril)
Asycube feeders are very flexible and are suitable for extremely gentle feeding of loose parts and components of all geometries with sizes from less than 0.1 mm up to 150 mm. (Image source: Asyril)
Asyril’s flexible Asycube feeders, in combination with SVS-Vistek’s EXO series cameras, provide a powerful alternative to “reaching into the box” and increase the productivity of the robots used. (Image source: Asyril)
The core of the image processing system used in the current Asycube feeders is a camera from SVS-Vistek’s EXO series. (Image source: SVS-Vistek)
SVS-Vistek has recently expanded its range of industrial cameras by 10 new USB3 models of the EXO camera series (exo342, exo367, exo387) with resolutions of 31, 19 and 17 megapixels. They are based on the innovative Pregius 2 CMOS sensors from Sony, which are highly light-sensitive with large, square pixels of 3.45 µm edge length and deliver an extremely high dynamic range.
The new products cover sensor formats up to APS-C and Four-Thirds. Due to their pixel size, Pregius 2 sensors can be operated with many cost-effective lenses even at high resolutions. For the high resolutions, the EXO series offers variants with M42 mount and the MFT mount for focusable lenses. SVS-Vistek thus offers its customers an optimum selection from a wide range of lenses for every task and enables economical solutions from a single source.
Despite their high resolutions, the new EXO cameras allow frame rates of 11.5, 18.5 and 21.5 frames/s with a USB3 bandwidth of maximum 360 MB/s net. This leaves enough room for the subsequent image evaluation until the next production cycle or the next object. Even higher image frequencies will be possible in the HR series with the high-performance interfaces 10GigE and CoaXPress.
The EXO cameras have an integrated 4-channel LED flash controller, which saves users the use of an additional device. Extensive sequencer functions, the milled housing with extraordinary sensor and adjustment quality as well as excellent temperature management ensure constant results over a wide temperature range.
In special tracer versions of the EXO cameras, low-cost MFT lenses (Micro-Four-Thirds) can be controlled via GenICam commands and allow the complete adjustment of focus, zoom and aperture to new tasks within milliseconds. All timings for sensor, illumination and lens come from a single source and are controlled via a single GenICam interface.
The compact footprint and image quality qualify these new EXO cameras for many applications with high resolutions, among others in the fields of apparatus engineering, traffic engineering, photogrammetry, surveying, aerial mapping, high-end security technology as well as solar, wafer and display inspection.