A concept demonstration of the ebbits platform took place at the project review meeting on 15 September in Brussels. For the ebbits scenario Automotive Manufacturing, the focus was on showing how tracking the energy and water consumption of a welding robot can be used to optimise production.
During the meeting, ebbits partners presented a status update of first year activities and the advancements toward the definition of a middleware oriented platform enabling the convergence of the Internet of People, the Internet of Things and the Internet of Services into the “Internet of People, Things and Services (IoPTS)” for business purposes. To illustrate the progress in the automotive scenario, a prototype of the ebbits platform was presented with the aim to highlight the potentials of ebbits-enabled IoPTS applications to manage production optimisation with special emphasis on energy consumption.
Tracking the energy and water consumption to assess efficiency more accurately
The demonstration emulates a welding cell with a single welding robot as shown on figure 1. The goal of the prototype is to quantify and track the energy and water consumption required for welding operations on a particular item. Such information can be used to assess the manufacturing process efficiency and the production cost in a more accurate way.
More specifically, the emulated scenario envisions a cell running an infinite production cycle where each cycle is focused on a single manufactured item. A PLC is in charge of controlling cell operations by interacting through a PROFINET field bus with the other cell elements i.e., Robot Controller and I/O interfaces. The I/O devices enable extraction of information from the cooling circuit and the power supply circuits. In the cooling circuit, two types of sensors are installed:
• A flux meter retrieves data concerning water usage/waste of the cooling system adopted for the welding transformer and the welding gun.
• Several thermometers are used to measure heat drained from the different devices that compose the welding circuit.
In the power supply circuit, two separate circuits for the robot axis power supply and for the welding power supply are considered. Using a voltmeter and an ammeter on each power supply, it is possible to collect data regarding power consumption.
Integration into the ebbits framework
The integration of the welding cell into the ebbits framework is performed through the PLC that is virtually connected to an ebbits gateway, in charge of extracting the information contained in its memory by using the OPC protocol. To this aim, a first preliminary prototype of the Physical World Adaptation Layer has been developed.
In this first prototype, most of the data gathered from sensors are simulated and inserted in the actual PLC memory according to the production step in which the manufacturing process is working. To this purpose, the demo includes a simulator able to interact with the PLC using the OPC protocol and to feed the simulated sensor data.
After retrieving information from the sensors inside the cell, the prototype is able to measure and log the instantaneous consumptions associating them to the current workpiece, properly identified e.g., by means of a barcode reader, from the actual PLC. The behaviour of the bar code reader is simulated as well. Multi-sensory fusion and context awareness algorithms are then applied to correlate and aggregate the collected measurements in order to generate reports or trigger alarms when an anomalous consumption is detected. More specifically, the system is able to infer whether the transformer is broken or a false positive is triggered by values sent by faulty sensors.
Figure 2 introduces the Graphical User Interace being used during the demonstration: It shows the current cell production status, the current values of the sensors, the information inferred for each produced item using Multi-sensory fusion and context awareness algorithms and, if needed, alert messages notifying sensors or transformer failures.
Showing the scalability of the project
Several field trials are planned to take place during the ebbits project. The next automotive manufacturing prototype is due in June 2012 and will include a selection of actual manufacturing sensors.
The last two prototypes, planned for June 2013 and June 2014, will show the partial/full set of ebbits features in a real world environment based on the previous field trials. For automotive manufacturing, it means working towards expanding the application to the whole manufacturing plant, correlating all the production lines and giving a full, easy-to-understand overview about the status of the whole manufacturing plant, hence demonstrating the scalability of the project.