‘Smart’ sensors have become an essential component in many manufacturing systems as the demand for ever more sophisticated automation continues apace across a huge range of processing applications. In many automated processes specific information is essential to ensure the smooth running of systems, typically provided by optical, inductive, ultrasonic sensors, or cameras. However, a more versatile, lesser known alternative are smart 2D profile sensors, such as the OXM 2D sensor, developed by sensing and instrumentation specialists BAUMER.
Image Credit: BAUMER
A good example of where these smart sensors have proven to be very effective is on a fully automated sandwich and filled rolls production line at a German company Weber Maschinenbau. The company specialises in developing slicing systems for food industry applications and their latest production line accommodates over 70 sandwiches rolling off the line every hour, perfectly topped with sausage or cheese.
For this application, precise edge control, margins and positioning data is essential to smooth operation, for example; what is the exact position of the sandwich or filled roll on the belt? We need to know its height and is the edge even? For example, the robot in the roll section needs to know roll height and centre (lengthwise and crosswise) and whether the roll may not be properly aligned on the belt. Basically, can one sensor provide the entire measured value calculation, and also deliver the calculated coordinates correctly in the units (millimetres) required?
The OXM sensor delivers all this information thanks to integrated measurement and evaluation functions. In other words, the entire measured value calculation is provided by the sensor including the calculated coordinates in millimetres - as specifically required. The sensor also measures the bread height and every edge to calculate the centre of the roll which enables suction pads to gently lift off the finished product without causing damage.
On the sandwich line, the sensor also determines the lateral position and height of the sausage and cheese slices on the belt allowing the gripper to position the slices accurately on the bottom half of the sandwich. Weber Maschinenbau exploits this functionality not only on its sandwich lines but also on the slicers that cut and portion cold cut optimally prepared for packaging. Here, the sensors deliver the position data required for precisely aligned slices of salami, ham or cheese, which is essential for allowing the finished product to always be placed in the same position in the packaging process.
Marco Nichau, Head of Automation at Weber Maschinenbau commented, “It’s important for us that we don’t have to spend too much time and effort in integrating sensors and because the OXM sensor transmits all the position information directly to the machine controller we don’t need an additional controller, saving space and reducing costs”. He added, “As the sensor is very compact and easy to connect, we were able to parameterise it via the intuitive web interface. Furthermore, its ideal for the sandwich line as its performance is unaffected by variations in surfaces and ambient light. These factors, combined with excellent support and response from Baumer, were the key factors in our choice”.
The latest versions of these smart 2D profile sensors are compact and lightweight with simple connectivity using a single cable via IO-Link, Ethernet and more. They provide measurement ranges of up to 500mm with a field view of up to 300mm and operate with a precision of up to 5µm. These features make the sensors ideally suited to height checks of assembly parts, control and positioning tasks in robotics, such as position checks of feeder parts for pick-and-place applications, or gap checks in automotive manufacturing.