Last week, I had the opportunity to visit the Centre for Robotics and Industrial Vision (CRVI), based in the Cégep de Lévis-Lauzon, Canada. I was able to see and share with experts the latest technologies in the field of robotics. On the CRVI website you will find all the information and details about their mandates. Their role is to help Quebec companies to use the latest advanced technologies. Thanks to government programs, they can benefit from it at a lower cost.
Robots have been used in industry for many years. In machining, welding, assembly, they no longer need to demonstrate their superiority over humans to perform repetitive, painful or dangerous interventions. Without lungs and muscles fearing for their health, they know how to replace humans in many cases. They are therefore particularly effective for simple and standardized actions.
Their programming did not allow them to adapt to a process variability until now. If the operator did not place the parts to be welded or machined in a very precise position, the robot could not perform its task properly. This constraint required the installation of costly templates or jigs. It has long limited their development by the low return on investment.
Two technologies should be able to improve these aspects and increase the penetration of robots into factories. This is the vision and pressure sensors that give the robot the sense of sight and touch. Intelligence remains programmed by human, but the robot is “capable” of making decisions and adapting to a process or product with small variations.
To understand what these two technologies can bring, nothing better than a few examples and a video.
The contribution of vision
The robot is equipped with one or more 2D or 3D cameras. These cameras take pictures of the area where the robot will intervene. A program analyzes the image. The robot’s programming then permanently shifts the robot’s position according to the information received.
In the example below, you can see a classic: Handling parts on a treadmill to arrange them properly. This is a FANUC robot. The vision is used in this case to identify the position of the piece to be taken.
Another use developed by the CRVI is the welding/machining trajectory correction. One or more cameras capture the image of the work piece. The robot is programmed in relative: it knows the trajectory to be accomplished. The image taken allows to give the starting location, and to calculate the precise displacement of the robot. To ensure quality, it is possible to define a trajectory change tolerance. If the position of the parts is too staggered with the “standard” position, the robot stops its action and the operator must intervene.
the gain for the company : less complex and less costly templates, reduced operating time to set up the parts (less precision required).
The input of the pressure sensor
The sensor can measure forces according to the 3 axes (X, Y and Z) as well as the moments on these 3 axes. This ability to “feel” force can be used in many applications, especially for humanoid robots. On the industrial side, this technology can be used to:
- Guarantee the assembly of one part in another. The robot knows the position of the piece to be assembled and the path to be carried out. If, during the course of his journey, he receives incompatible information (e.g. misaligned or poorly calibrated part), he corrects his trajectory. If the part does not match the assembly tolerances, it will stop its action. The operator is responsible for checking the quality of the parts.
- Standardize a product: If two pieces are to be assembled with a force of 10 pounds, the robot will adapt according to the hardness of the materials and their variability. In this way, the assembly will always have a strength of 10 pounds. It modulates the pressure applied according to the information returned by its sensor.
the gain for the company : the possibility of automating and standardizing a process, a result with a constant quality level.