Palletizer cell – DERO

Luke van der Burg, Joris Kortekaas, Martin van Langevelde en Wouter Lettinga


Dero is an expert in the automation of production processes with robots. Their production site is located in Nieuw-Vennep. DERO is part of the DERO GROEP, a set of companies that have an intensive collaboration. Other companies in this group are ELTEN, BOSGRAAF and PACKTECH. 

Beside the automation of production processes they are also distributor of different robots for example Fanuc and Stäubli. 



Since DERO is a distributor of the Taiwanese Techman they are researching the different possibilities of the Techman robot. Techman functions with TMFlow, this is a software developed for the Techman. The TMFlow is a flowchart programming language. The advantage of drag and drop is that a non-programmer can create a working robot really easy.

One of the ideas DERO came up with is a palletizing cell. This cell will include a Techman and a SKF Lift Kit. The intention with the lift is to mount the Techman on there, so the robot will be able to stack the layers up to more than two meters. 

For the assignment we have to integrate the SKF Lift Kit with the Techman robot and write a palletize program. The palletize program must include a weight quality check, a box on gripper check and communication with a PLC for feedback to the user. 





Since the Techman is a quite new robot with a for us unknown software we first dove in the software. This to find out how the software functions works and what the possibilities are. 

After some research we discovered the TMFlow has a built in palletize algorithm. The advantage of this node is that you are able to easily build a palletize function. The disadvantage of the palletize node is that you are not able to interrupt the palletizing. The consequence of this is that it is not possible to do a quality check or a box check, to fix this problem we build ourselves a palletizer algorithm in TMFlow.
After some testing and trying to implementing the quality and box check we came to the conclusion that TMFlow is limited. This means we cannot build the palletize algorithm with all the requirements in TMFlow. 



Because the TMFlow software turned out to be unsuitable for the solution we want to create, we had to find a workaround. We found the solution in the programming language Python. This because python is an open source programming language and a lot of research has been done.  
The first matter we encountered was the connection between the Techman and the python code. The solution we came up with is a TCP connection via the listennode in TMFlow. This makes it possible to write a palletize algorithm in Python and send locations to the Techman.
Furthermore, the python code includes the communication between the Techman, PLC, lift and Arduino.


In the final solution it is possible to control the palletize cell with only the PLC.
You can select a box type and start and stop the program with the PLC via the interface on the HMI. While the robot is building the pallet the HMI shows an interface of the progress from the pile. 



To grab the boxes we made the decision to use a vacuum. The reason we choose for a vacuum with suction cups is because the boxes can be placed closely against each other. The final solution is a 3D printed mounting plate with 2 special box suction cups. 



We took a big step in making Techman robots more flexible. Also it took some time to figure out how the LiftKit could be implemented in the system, on the field of software. In the end we were able to get the system working and we stacked full pallets of different types of boxes. This way we were able to prove the principle. For the system to be implemented, it needs to be further developed, mainly the quality control, feedback through the HMI and details for positioning.