Each year software is playing an increasingly important role, also when it comes to tractors. It is no longer possible to count the number of lines of code, as a single hydraulic valve from an outside supplier can contain as much code as an early HiTech tractor. Advanced software also allows a tractor’s functions to be altered after production.
Software development, like all other tractor engineering, starts with the customer.
“There is an infinite number of needs, so it is the job of product management to prioritise them. These priorities are then used to create projects for our software development system, in which demands are split into small technical parts so the work can be divided. The development phase is two times three weeks, with functional testing after three weeks and validation after six weeks. The validation team tests whether the new software meets customer demands. The project list shortens, but new projects are constantly being added to the list,” says Pekka Huuskonen, head of software development.
The new software is delivered to the factory and service teams, which can distribute it to all tractors using the Electronic Diagnostic Tool (EDT). Valtra service technicians around the world use EDT to download the latest software to tractors during servicing. This is one of the many advantages of having tractors serviced by an authorised Valtra dealer.
C code, QT code or UML
Traditionally software developers have programmed directly in C code. QT code is then written for user interfaces. User Experience (UX) and Graphic User Interface (GUI) work is also involved. These days a lot of code is made by modelling, which involves Unified Modelling Language (UML) or Simulink code.
“The control of a multidisc clutch or engine fan, for example, is hard to describe mathematically, let alone with code. It is easier to demonstrate by simulating how you want it to function and having the modelling software create code for this. The final software is usually a combination of handwritten and modelling code,” Pekka explains.
The challenge with tractors compared to computers or cars, for example, is that the conditions and ways in which they are used vary enormously.
“Anti-slip regulation, or ASR, is relatively simple in terms of code: if a tyre slips too much, then ASR limits engine output. But inventing this function, finding the limits and other background work required research on the level of a doctoral thesis,” says Aleksi Vesala, a specialist in the algorithms of automated transmissions.
ASR is also a good example of how software can be used to add new capabilities to existing tractors. ASR can be added with a simple software update providing that the T4 Series tractor already has the required sensor. In the future, the number of new functions that can be added in this way will no doubt increase.
Safety considerations create their own set of challenges for software developers. If the software in a television or mobile phone crashes once in a while, or stops to think for a few seconds, there is no great danger. Tractors, on the other hand, have to react to all control systems and commands instantly, regardless of the implement being used, the conditions in which it is being driven or how the operator is driving the tractor. The reliability of a tractor’s critical software really is on a completely different level than that of consumer electronics.