The project ‘Robotics and flexible automation of food product packaging’ known as ‘PicknPack’ is a project of 4 years duration which holds a total budget of EUR 11,88Millon and an European Union contribution of 8,76Millon. It is coordinated by the University of Wageningen in the Netherlands and the consortium is made up of 14 partners from 9 different countries, including Tecnalia from the Division of Industry and Transport.
PicknPack began on November, 2012 to provide the European food industry the benefits of flexible production, offering the advantage of reducing costs by increasing safety and hygiene in the packaging of its products by combining the unique ability to adapt to each product and lot size.
In PicknPack 3 main modules that work in close cooperation are developed: a sensor module for evaluating the quality of the product, a robotic handling module guided by machine vision and an adaptive packaging module. The work developed by Tecnalia focuses on the second module, the robotic handling module guided by machine vision, in which a novel cable robot has been developed and patented.
In the last years, a novel concept of robot has become a main actor for the food industry. Those are the parallel kinematics manipulators (PKM) also known as spider robots, open chain kinematics manipulators or parallel robots. Although these robots are not the only ones that are used in the food industry, their growth in the last years has been very important. Their success is mainly base on their very high-speed robots (the food industry requires large volumes) can be inverted mounted (the products are usually transported on conveyors or belt systems) being suitable to manipulate light pieces. However, parallel kinematics manipulators or delta robots, are not easily reconfigurable in workspace and have a no optimized footprint. Pickable, the cable robot developed by Tecnalia, tries to solve those drawbacks. Pickable is an alternative to these robots which maintains the same dynamics, reducing costs, improving flexibility, making the volume of work more efficient and improving the required footprint. Tecnalia considers cable robot will answer the demand on market for many applications that do not require extreme precision but need to work at high speed for large volumes, as in the case of many current automated handling applications.
Pickable is based in the same principles as industrial parallel robots to manipulate and place objects at high speed, but the rigid bars are replaced by metallic cables. The cables are connected to a mobile platform at one side and enrolled on winches that control the length and tension of the cables for the controlled movement of the platform on the other.
To easy the robotic handling, a machine vision system to locate food packages has also be worked out. Its objective is to calculate the picking position of each package to update the coordinates with the movement of the conveyor and to send them to the cable robot in order to carry out “conveyor tracking” which consists in grasping the food packages from a conveyor and placing them in boxes.
For the optimal selection of the hardware and based on the previous specifications, different cameras (linear and matrix) and different lights configuration (diffuse, direct, high power, fibber, etc.) have been tested. Finally, a linear monochrome camera with a high power linear lighting was selected. This vision system and the selection of the appropriate gripper, provides to the cable robot the necessary flexibility and ability to adapt to different package sizes in random positions.
The complete vision system has been integrated into the design of the cable robot attached to the frame for an easily configuration and calibration of both systems. By this way, the distance between the coordinate systems (camera and robot) are fixed and known.
Because of its innovation, cable robot patent has been requested with registration number PCT EP2014 / 078 932 “Planar Motion Device”.
This innovative manipulator will revolutionize the manufacturing robot market allowing, with the same design concept, adapting the robot workspace to new dimensions in a simple and efficient way.