In the factory of the future, humans and robots will collaborate to an increasing extent. Based on this vision, RoboJob develops innovative systems for the automated loading of machine tools. Safety laser scanners from SICK ensure maximum safety.
The automated loading of milling machines and lathes has now become standard practice in areas such as metal processing. Once the machine has been programmed for a particular machining stage, it is easy to integrate a robot which feeds in the components in sequence and removes them again. This creates a fully autonomous production cell. “Suppliers in the metal industry must use automation in order to remain competitive,” explains the CEO of RoboJob, Helmut De Roovere.“ The prices for CNC machining are determined at an international level. Businesses have to deal with growing production costs and the difficulty of finding workers with the right technical qualifications. Automation can be the solution to these problems.”
RoboJob is part of the Aluro Group, which also includes Aluro bvba, a high-profile manufacturer of machines for the aluminum industry. This Group also includes Aluro CNC, a supplier active in the machining industry, which was itself faced with the challenge of maintaining its competitiveness ten years ago. As the company could not find any suitable automation solutions on the market, RoboJob was founded. Today, RoboJob is the market leader in this industry and sells its systems both in Belgium and abroad.
Robots and operators working on the machine simultaneously
“One of the main reasons for us developing our own solution was that the CNC machine had to remain accessible,” continues Helmut De Roovere. “For supplier companies which produce small ranges of products or even individual items, most of the work is done directly on the machine. The conventional solution of placing the robot in front of the machine with a safety perimeter around it would make this impossible. Our solutions – namely Turn-Assist and Mill-Assist – place the robot adjacent to the machine so that both the robot and the operator can easily work on it.”
Another feature of RoboJob’s solutions is the flexible tables from which the robot takes the components being machined. These tables feature a system with adjustable clamps and brackets that can be adapted according to the products being manufactured. The height of the tables can be set automatically so that the robot knows exactly where it should take the component from or where it should place the next component. A third feature of Turn-Assist and Mill- Assist is that the robots are not surrounded by a safety perimeter. Instead, the precisely defined surroundings of the robot are monitored with safety laser scanners from SICK and are connected to the robot’s safety controller. RoboJob was one of the first companies to apply this concept to these kinds of applications.
Intelligent hazardous area protection
The principle of operation of a safety laser scanner is simple. Installed at floor level next to the robot, it scans the surroundings. Different areas, which are known as fields, can be taught into the scanner. If the safety laser scanner detects a person in one of the defined fields, it sends a corresponding signal to the robot’s controller.
“One of the advantages of the scanner is that two fields or – depending on the scanner version – even more fields can be defined,” stresses Helmut De Roovere. If a person enters the outer field – known as the warning field – the safety laser scanner sends a signal to the robot’s safety controller. The controller then reduces the speed of the robot and also emits an alarm signal to warn the person that he or she is too close to the robot. At this stage there is no danger to the person and the robot can continue operation. If the person then moves closer and into a further defined field – the protective field – the controller stops the robot.
Safety limits for the robot working area are programmed into the robot’s controller. These ensure that the robot does not move outside of the working area necessary to carry out the task at hand under any circumstances. Various protective fields are activated in the safety laser scanner on the basis of these safety limits. The protective field is always somewhat larger than the working area of the robot. This ensures that any personnel are detected in good time and that the robot is stopped before a hazard arises for the person.
A system that allows the operator to collaborate with the machine
Helmut De Roovere continues: “Using safety laser scanners is a key part of our efforts toward making the production cell as accessible as possible. We want a system which takes the operator into account and makes adjustments for him or her – not the other way round. With this in mind, we have developed a user- friendly platform which is linked to the robot’s controller and is adapted to how the operators use the system.”
RoboJob wants to go one step further and make better use of the variety of functions offered by the safety laser scanners. According to Helmut De Roovere: “Today we have two protective areas which are defined in conjunction with the working range of the robot. We want to improve this by adapting the protective fields dynamically to the operation carried out by the robot at any given moment. With the risk analysis, we can ascertain which areas have to be protected at a given point in time for each position and each movement of the robot. This would give the operators more room to work safely in the vicinity of the robot. In doing this, we are working on the principle that the robot must take the operator into account. Operators can then carry out their duties on the machine and the robot can continue to operate. This increases productivity thanks to the safe collaboration between humans and robots.”