13 décembre 2018 Developing the industrial assembly station for Industry 4.0 environment
“Developing the industrial assembly station for Industry 4.0 environment” is the title of the seminar that was held by Fiam at its premises in Vicenza on 5 December. The director of Industria Italiana magazine, Filippo Astone, has moderated the work. The seminar has been a training occasion for production companies wishing to improve their assembly processes to achieve enhanced productivity and competitiveness by using strategies that involve the adequate design of flexible production systems, the study of machine tending logics and the provision of tightening stations with a view towards the use of new robot technologies.
The seminar, sponsored by the Veneto Region, has been part of the planned activities for business internationalisation and has aimed to offer industrial partners knowledge and experience on themes associated with the concept of Industry 4.0 within the framework of strategies for competitive development in globalised environments. Seminar speakers have been Maurizio Faccio, Professor of Mechanical Systems and Industrial Plant Management and Giulio Rosati, Professor of Mechanics Applied to Machinery and Industrial Robotics, both from the University of Padua. There have been question and answer sessions as well as practical workshops with collaborative robots to accompany the teaching activities.
‘The introduction of the collaborative robot opens new manufacturing scenarios. Connecting the work station makes it possible to support operators during operations, not replacing them but helping them. This model of collaboration between robots and humans is not applicable to all kinds of industry and all kinds of operations. However, we can show that for certain situations, this is the best possible scenario for companies.’ Maurizio Faccio and Giulio Rosati are respectively associate professor of logistics and industrial systems, and ordinary professor of mechanics applied to machines, both at the University of Padua. In an interview with Industria Italiana magazine, both academics reveal the initial results of a study that was presented during the “Developing the industrial assembly station for Industry 4.0 environment” conference.
The evolution of the work station
The assembly station is generally a manual station that needs to be extremely flexible. ‘The various products,’ explain Faccio and Rosati, ‘may have different variants. For this reason, operators must first have the information they need to perform the assembly in the best way. Supporting operators, informing them of the sequence of operations, selecting the products to be picked up: these are the main functions of a connected work station.’ In the tightening world, for example, there are different sequences depending on the angle to be applied or the activities to be carried out. ‘Controlling the sequence of operations,’ they continue, ‘means supporting operators’ activities in the face of product variability.’
In manipulation, some operations must be performed automatically: here the robots come into play because they are ideal candidates for assembly. So far we have been accustomed to two views: either operators use mechanical tools, or the assembly process is fully automated. ‘But today,’ explain the two professors, ‘with the introduction of Industry 4.0, sensors and technologies help us and we can imagine using a collaborative robot, which opens completely different scenarios. In fact, this tool makes hybrid human and robot operations possible. The fundamental aspect is that it offers greater freedom to divide tasks between operators and robots, making it possible to automate and make better use of operators’ skills. This automation can maximise the efficiency of both operators and robots. Specifically, humans can only carry out tasks with high added value, while tasks involving mere handling, such as picking components up from the magazine, are carried out by robots.’
So, contrary to what has been feared for a long time, machines are not destined to replace humans, but to collaborate with them and free them from the heavier and more dangerous tasks, allowing them to provide the real added value in the production process. ‘The added value,’ argue Faccio and Rosati, ‘continues to come from the humans: operators become the ideal instruments for carrying out complex operations. Note that collaborative robots have significantly lower performance than traditional industrial robots. The automation to which we are accustomed speeds up repetitive operations. Collaborative robots, however, create a kind of functional ecosystem in which the best features of humans and robots work together.’
So, the two academics are developing a model to assess both the productivity and direct unit cost of production with different automation systems, from rigid, through flexible, right up to collaborative. The study was conducted on some companies in the north-east, where the application of collaborative robotics is in its infancy, but above all, does not depend on incentive mechanisms: the machinery was not chosen on the basis of hyper-amortization or super-amortization, but by calculating economical convenience.
Collaboration vs automation
‘The chance to create an economically convenient system,’ explain Faccio and Rosati, ‘led us to develop this model: while with traditional automation, everyone simply calculates the costs and benefits in terms of productivity and time, with collaborative robotics, they must look at other aspects, which are more qualitative than quantitative. We can say that companies find these new technologies very attractive, but they tend to give more weight to emotional aspects rather than traditional assessment.’
To guarantee high safety standards, collaborative robots, which are slower than traditional ones, have additional sensors so that they can continuously monitor the operator’s position. There must also be software measures to prevent robots from exerting excessive maximum force. ‘In essence,’ the two academics say, ‘collaborative robots are not so different from traditional ones, but they are significantly slower because they have an operator beside them. In addition, sensors change the robots’ posture to prevent potentially dangerous contact. Regarding technological applications, tightening is one of the sectors that can best exploit the collaborative approach. But precisely because there can be greater interaction than in other sectors, special certifications are needed. For example, the robot hand: manufacturer make a collaborative gripper with a maximum force of 140 Newtons, the maximum permitted by the standards in force. This costs more, but it is the only way of making interaction with human users possible. Then, on one hand, slower movements limit the risks to the operator, but on the other they mean greater loss of time. Therefore, it is necessary to carefully study the sectors in which applying and using collaborative robots can be most effective.’
A new factory approach in which robots and operators must interact also means that the company must implement a training process. ‘This revolution of the work station,’ conclude Maurizio Faccio and Giulio Rosati, ‘means that operators will have a more varied role with greater added value.’ It is necessary to widen the skills of human activities through a mechanism of ‘job enlargement” in which they are required to carry out the more critical activities. It is a mechanism that makes daily work more motivating: instead of carrying out repetitive tasks, workers perform more qualified jobs.’