Speed, safety and process reliability: the advantages of a robotic automatic pieces unloading system

Flexibility and productivity are two important subjects for the manufacturers specially nowadays when the energy cost and the raw material availability are often hard to be managed. Ficep faced these themes many times offering different solutions depending on the customers’ needs: contractors, earth moving machines constructors, ship builders, steel fabricators, etc.

Gemini, for example, is a plate drilling and cutting system which can host different technologies, such as:

• thermal cutting (plasma with straight or bevel heads and oxy);
• marking;
• drilling;
• tapping;
• milling.

The positioning of the plates on the working bench (typically carried out by crane) and above all the unloading of the processed pieces, still represent an issue. The unloading operation is usually done manually directly from the bench or thanks to big magnets which collect groups of pieces, to be picked and organized manually on the floor. The possibility to improve this activity, making it quicker and safer, has always been subject to the market requests and to the machine tool manufactures’ analysis.

Automatic unloading robot

Since the parts processed on the Gemini have different size and weight (within the same plate or on different plates), it’s imperative to find an efficient but flexible solution. The first Ficep prototype of robotic system to unload the processed pieces is the result of a specific customer’s request.

Gemini is made of one working bench and two parallel rails which the gantry slides on. Often the system is configured with two gantry machines: Gemini can be combined with one Kronos. The first one performs all the mechanical operations such us drilling, milling, tapping, chamfering etc, while the second carries out the thermal cutting. On the rails, as alternative to the Kronos, it is possible to install the robotic system for pieces unloading.

Once Gemini ends the working cycle of a plate, it moves to the second plate so that the robot can start the unloading activity on the first one without interfering with the Gemini operations. For this reason the working stations must be at least two (one for the working cycle and one for the unloading) or more, up to a maximum of eight stations.

The picking element is made of two pneumatic-magnetic systems which can symmetrically converge or diverge with respect to the arm center to change the dimension of the picking point. In this way the system is able to pick both small or large and heavy pieces: it is also possible to adjust the magnetic level of the picking element according to the characteristics of the piece to be handled.

The operating software

Although the Gemini and the robotic system are two different machines, they exchange the data to optimize their activities: the position of the piece within the working bench is already known in the software. Gemini in fact is previously checking the exact position of the plate, which is usually not perfectly aligned with the working bench, and the software is rotating and adjusting the program accordingly. This information is very useful also for the robot software in order to program its working cycle.

The whole cycle is therefore based on the information coming from the nesting realized with Steel Projects software, Ficep software house, which uses these data to program the automatic unloading with the robot.
Piece type, position on the bench, weight, barycenter and other data are collected by a software specifically developed to generate the pieces unloading program.
The software also identifies the shape and dimension of the part to define the best picking point.

The unloading can be managed and organized in different ways, for example by properly palletizing the components according to specific criteria.
The pallets are positioned in specific areas and are managed by sensors. They can be moved manually or through AGV. It’s also possible to stockpile the empty pallets: once the first pallet is full and removed, the software automatically recognizes the different height of the new unloading level of the second pallet.

The use of a robotic system with anti-collision devices and photocells to remove the processed pieces from the working bench instead of the manual unloading by the operator allows to highly improve the overall safety of the system.