Groundbreaking innovations have always been accompanied by the introduction of new development methods. Not only the products themselves, but also the corresponding development methods are subject to a constant process of change.
The machine manufacturing industry seems to be the exception to this rule. The development cycles here have hardly changed in years. But why such a conservative approach?
Is the market pressure in this industry any less than in other areas? Or have we already found the best possible development strategies, leaving no room for improvement?
The first is certainly not true in times like these. The price pressure in machine manufacturing is higher than ever, and the only way to keep up with it is through distinctive innovations combined with efficient development cycles. The second question also has a clear answer.
Terms such as model-based design, simulation, automatic code generation, rapid prototyping and hardware-in-the-loop are already well-known in the automobile and aerospace industries, for example. It seems that there is potential here just waiting to be tapped by machine manufacturers.
The price pressure in machine manufacturing is higher than ever and the only way to keep up is through distinctive innovations combined with efficient development cycles.
What better time for gaining new competitive advantages than now? Some especially innovative sectors, such as wind power, have already taken the decisive step. Now it would be hard to imagine an integrated development process without the methods described below.
Model-based design
Model-based prototyping processes create the foundation for integrated, sustained development. Nevertheless, scepticism often wins out – the high initial cost for creating a model scares off many developers from making that first decisive step.
Yet the simulation model of a machine plays a very important role. The success or failure of the model-based development process depends on it. In how much detail do the processes in the system need to be described? Where simplifications can be made?
The greatest investment is required when modelling the behaviour of a machine occurs at a very early phase.
Unfortunately there is no blanket statement that can be made here. There’s no question – the greatest investment required when modelling the behaviour of a machine occurs at a very early phase of the development cycle.
Yet once this obstacle has been conquered and the system has been modelled effectively, a great number of advantages suddenly arise for the machine manufacturer.
This development process not only adds depth to the manufacturer’s knowledge of the machine, it also synthesizes expertise from multiple departments into one place.
Unlike with binary data or even source code, simulation models are most often prepared graphically, and are therefore to a great extent self-documenting.
Once it is created, the model provides a sustainable foundation for future development and optimisation, which means the relatively high initial investment pays off quickly.
Not to mention the additional methods available in the development process, such as simulation and automatic code generation – which easily take advantage of the model-based design approach.
Simulation
A complete model of the system that illustrates the machine’s processes in the greatest possible detail, is the basic requirement for creating useful simulations.
Once this requirement is fulfilled, design errors can be detected and corrected in early design phases, based on the results of simulations, instead of later on when they represent a risk to the machines and operators.
The gap in the development process can be filled easily using automatic code generation.
The later in the design process an error is detected, the more expensive it is for the machine manufacturer. In this way, simulation modules can contribute indirectly to cost savings. The reduced need for expensive physical prototypes and time-consuming testing also results in increased cost and time efficiency.
Even after a machine series is manufactured and delivered, simulation models continue to be quite useful. They enable the manufacturer to react quickly and flexibly when market demands change and to test the effects of modifications to the machine or controller.
Automatic code generation
Model-based design and simulation are one side of the coin – but implementing the created structures on the industrial hardware is the other. Some new developments that work perfectly in a simulation come to an abrupt halt at this point.
Yet the problem is mostly trivial – to implement the solution in a high-level language required by the industrial controller would simply be too time-consuming.
The automatic code generation is practically invisible if the right tool is used.
As a result, all the advantages that the developer gained through using model-based design and simulation models are negated when trying to implement them in the field.
Or are they? This gap in the development process can be filled easily using automatic code generation. Almost like magic, system and controller models are transformed into finished software objects that can be transferred directly to the industrial controller.
At least provided the right tool is used, which supports the user through the entire process and makes the automatic code generation practically invisible.
Just a few clicks in an existing Simulink model, and the B&R tool – Automation Studio Target for Simulink – automatically implements the respective software object on the controller.
What is essential is that the behaviour of the automatically generated source code is absolutely identical to that of the simulation module.
Rapid prototyping
Rapid prototyping and hardware-in-the-loop are two terms that are closely related to model-based design. But what exactly do they mean? How can machine manufacturers profit from them?
Once a model-based control algorithm has proven itself in the simulation, it should be transferred as quickly as possible to the target hardware for industrial use, where it can be given the final test under realistic real-time conditions.
If automatic code generation is used here, this is called "rapid prototyping".
Construction of conventional physical prototypes involves additional costs and is time-consuming. Rapid prototyping, on the other hand, takes only a few moments and hardly any actions from the user – provided you’re using the right tools.
But, if control structures can be designed using system simulations and transferred to the industrial controller using automatic code generation, why shouldn’t this also be possible for the system model itself?
Using automatic code generation system and controller models are transformed into finished software objects.
The industrial controller has come to be much more than a simple microprocessor. It is a powerful computer that is fully capable of handling complex system simulations in real-time.
These "hardware-in-the-loop" simulations allow an industrial controller or an industrial PC to be quickly converted into a system simulator that emulates the behaviour of the actual system in real-time.
The applications are numerous; a hardware-in-the-loop system can be used for training purposes or to safely test new controllers. It is also possible to operate it parallel to the physical system for early detection of errors.
Wind power
In most areas of machine manufacturing, model-based design, simulation and automatic code generation are now slowly gaining importance, but in the wind power sector they are already common practice. To what do they owe this head start in the use of new development methods?
Are the engineers in the wind power sector generally more innovative than their colleagues in other areas? Although many factors may play a role here, the actual main reason is obvious.
More so than in other areas of classical machine manufacturing, the testing of new wind power technologies involves great risks for humans and the environment.
Wind turbines are generally located near populated areas, which means that errors in controller design or in the performance of the machine could have fatal consequences.
Test failures on a real turbine also result in exorbitant costs, which is a strong motivation to take advantage of model-based design and simulation models.
Yet another reason for the use of innovative design methods is the fact that wind power is a relatively young industry that has only been on the scene for a few years. The success speaks for itself.
As the wind power sector focuses on creating a consistent workflow – from model-based design and simulation to automatic code generation – it continues to gain importance on the market. Innovative development methods are the key to success.
[Philipp H. F. Wallner works in the area of systems and control technology at B&R.]