The Swedish company DeLaval specializes in the development and production of machines that are primarily used in the dairy industry. The DeLaval OptiDuo™ was also designed to make work easier for farmers. The device is a robotic feed pusher that moves autonomously through the center aisle of a barn. It not only pushes the feed on the feeding table closer to the cows, but also loosens it up and mixes it to make it more attractive to the cows.
Initial tests under real conditions showed that the robot pushed the feed closer to the cows and loosening it up was no problem. However, the play instinct and curiosity of the animals repeatedly caused the feed pusher to come to a standstill. This emergency stop was necessary to prevent possible dangers, for example if the cow did not move her head away despite being touched. At the same time, however, it also meant that the machine would only continue to run after the farmer manually restarted it. This took up too much time, which was needed elsewhere. A safety solution had to be found in order to use the robot with the battery-powered drive as profitably as possible. Not only the emergency stop functions and an enable button for starting the vehicle were absolutely essential. Safety edges for temporarily stopping the robot when it touches an obstacle, a protective flap to provide access to the danger zone and safe monitoring of the battery charging function were also crucial for DeLaval when choosing a safety solution.
Help was finally found at DINA Elektronik. Our team developed a solution that included all the required safety functions. No other provider was able to do this. DeLaval therefore decided to use our SAFELINE VARIO central module ZMV. The decisive factor was the "safety edge" function, which is part of the standard scope of the product without the need for an additional module. For the OptiDuo™ to function properly, it was also necessary to be able to program different waiting times until the restart as required. Briefly tapping one of the side safety edges causes the OptiDuo™ to stop for ten seconds and then restart automatically. If the safety edges are pressed within the next ten seconds or for more than five seconds, the emergency stop function is activated. In order to fully meet DeLaval's requirements, we had to make some customer-specific modifications during the test phase. For example, the Swedish company wanted to do without the additional CANopen fieldbus module in order to work as cost-effectively as possible. However, as this meant that an important communication protocol for networking within the robot was missing, a replacement was absolutely essential. Instead, the "SDIAG serial diagnostic outputs" function was developed. This allows status messages to be output digitally, indicating why the device has come to a standstill and how the problem can be rectified. This customer-specific development was then integrated into our SAFELINE-VARIO safety solution as standard.
The tactile safety edges fitted around the OptiDuo™ are intelligently connected via the ZMV central module. If the robot encounters an obstacle while moving forwards, the vehicle stops by triggering the safety edges. When driving forwards, only the front bars are active. Conversely, this also works with the "reverse parking" option. In this case, only the rear bars are activated and the feed pusher also stops automatically when they are touched. Thanks to the intelligent wiring and the various programmable waiting times, the OptiDuo™ automatically restarts if the bars have not been touched for longer than five seconds, if they have not been touched twice in succession or if they have not been touched more than once within 15 seconds. This function makes a major contribution to ensuring operational safety after the vehicle has touched a cow or other obstacles. After a pause of ten seconds, the battery-powered drive restarts safely and the feed pusher resumes its normal operation.
The intelligent functionality offered by the SAFELINE VARIO central module ZMV results in a significantly more efficient working performance for the feed pusher. During the testing and development phase, the farmer had to constantly check whether the OptiDuo™ had encountered an obstacle and then restart it. The robot can work around the clock if necessary, which also makes the cows more active and brings them to the feeding table more often. This ensures that the animals are adequately fed to make full use of their milk yield. The fully autonomous and automatic solution also reduces feeding time enormously, leaving the farmer more time for other farm activities.
Following the successful series launch of the OptiDuo™ with integrated SAFELINE VARIO central module, our safety solution can now also be relevant for other DeLaval devices. Thanks to the integrated speed and standstill monitoring, the SAFELINE VARIO is an attractive solution, especially for drives where speed monitoring plays a major role in operational safety.