Slashing or docking the surface of bread dough prevents the occasional uncontrolled bursting of loaves as they bake and expand in an oven. This process also produces an increase in the surface area of the loaf as it bakes, resulting in a larger crust. Professional bakers slash the bread dough manually with a tool known as a lame. However, in modern factory environments that produce bread at a rate of 4500 loaves per hour, employing manual workers to perform such tasks proves inordinately expensive.
Engineers at Akéo Plus (www.akeoplus-vision.com) have developed a vision-based robotic system to automate this procedure for a large French bread manufacturer.
Prior to baking, trays carrying uncooked balls of dough covered with flour pass under an inspection station. As they do so, they are illuminated consecutively by a red-and-greenLED-based linescan illumination system. Images of the dough are then captured by a 5-Mpixel camera from Cognex.
Image data are transferred over a GigE interface to a PC that reconstructs a 3-D image of each ball of dough on the tray. These 3-D data are then sent to an M20iA robot fromFanuc equipped with a lame that moves across the trays of dough to slash the surface of each of the balls before they move into the oven for baking. According to Akéo Plus's Stéphane Morel, custom software identifies the balls of dough on the trays and instructs the robotic lame to move in the optimum path across the top of the dough.
