Keeping an eye on robotic vision systems

As vision systems get more sophisticated and user-friendly, the range of applications for this technology continues to grow. Katherine Crichton looks at the integration of 3D vision into robotic cells.

As vision systems get more sophisticated and user-friendly, the range of applications for this technology continues to grow. Katherine Crichton looks at the integration of 3D vision into robotic cells.

IN an increasingly competitive marketplace, making mistakes is not an option for Australian manufacturers.

In an industry where errors can be costly, in terms of both dollars and reputation, advances in 3D machine vision guidance with robots is providing quality control that is impossible to match using the human eye.

However, despite the many QA, productivity and safety benefits robotic vision guidance systems offer, the technology hasn’t gained wide acceptance locally.

As Paul Gekas, GM of ABB Robotics Division (Australia) says, “Even though vision in the past has offered a possible solution to some of the limitations of traditional mechanical methods in automated manufacturing processes, often these benefits were not realised.

“Where identification of a component is necessary to automate a cell, particularly in materials handling and assembly applications, ineffective positioning of a product renders the process cost prohibitive, with vision the only possibility.

“However, traditional machine vision systems weren’t very robust, were complicated to implement and difficult to maintain, but this has now changed with the introduction of new, more advanced robot vision guidance systems,” Gekas explained.

“Systems are now being designed using off the shelf products such as standard PLCs, cameras and image capture cards etc, but have been integrated with features specifically designed for ease of use,” he said.

Robots can now be programmed to position the camera and adjust the lighting to an optimal image capture location, allowing for automatic calibration and part training – which in turn shortens solution development and integration lead times.

While most vision guided robotics systems use multiple cameras, ABB has developed a solution using only a single camera, which Gekas says, eliminates the historical installation challenges involved when attempting to combine disparate hardware, software and integration practices into a functional system.

“By using a robot-mounted single camera and variable lighting package, TrueView is capable of full 6 degree-of-freedom 3D vision guidance.

“Having multiple cameras may be able to provide additional information as required, but in most cases generally speaking one camera is more than sufficient,” Gekas said.

Another feature of vision guided robotic systems is development of a test mode function, allowing manufacturers to simulate the conditions of their production line i.e. component position, lighting density and environmental factors.

“With traditional systems, normally you would have to put them straight into production, see how they behave and then pull the systems out of production in order to make any necessary adjustments or parameter changes.

“This system allows the user to see how the system will react and test its robustness well before it goes into production.”

Big benefits for SMEs

The increasing development of technology is driving the prices of vision systems down, making it far more affordable for small to medium enterprises.

Matthew Boyer, Senior Systems Engineer with Sage Automation, says nowadays it is not just the large companies enjoying the benefits of the machine vision.

“Smaller suppliers are investing in the technology, and we are seeing systems move into a range of new applications, evening mining operations.

“Advantages of putting a vision system on a robot — giving it eyes and taking away the human element — is providing safety and quality control benefits for manufacturers,” he told Manufacturers Monthly.

“Robots are a lot faster than a person, so if you put a camera on a robot it’s not only getting rid of an element of the QA process, but it is making it a lot more efficient.”

Boyer said labour is the typical opportunity for cost saving but there also other factors such as ergonomical issues, foundries and lifting of heavy parts.

“There are additional benefits, such as faster production times because manual loading and unloading of parts is eliminated and reduced safety problems because employees are no longer lifting and carrying parts.”

Another major saving for manufacturers can be in warranty costs, which Gekkas says can be quite draining for manufacturers.

“If a product has been scrapped or damaged through the existing automation process and put into the assembled product, whether it be a car engine or some other part, this can incur some significant warranty costs down the line.

“The finished product may cause an oil leak, because the seal isn’t made properly as a result of the initial damaged component.

“The more you can guarantee the quality of a product, the more likely a reduction in warranty costs.”

Both Gekas and Boyer say despite the hype, robots and 3D vision technologies will not take away the human element in manufacturing processes, which will still play a major role in future manufacturing operations.

“It’s not about getting rid of people but trying to get the productivity out of the people that are there,” Gekas said.

“In another five years, the technology will only get faster and more efficient, but ultimately these developments are driven by customer demand, and unless companies start investing in the technology, it will be a slow progression,’ Boyer said.