Why did Liebherr develop its own crane control system?

Erwin Morath: When I first came to Liebherr in 1985, there was a range of different hydraulic, electrical and electronic control systems, depending on the crane model. We only had a simple system of our own to limit the load moment (LMB). We therefore launched the LMB from PAT, a wellknown manufacturer at the time. However, electronics were only available with analogue systems and did not feature any variable programming options. New plug-in boards had to be developed for each crane.

Max Leicht: This plug-in board technology was only able to cover a certain amount of the crane control system. The requirements for the crane control system increased as a result of the ongoing development of our crane portfolio. That meant that new integrated circuits had to be developed on the plug-in boards. Over time, we developed around 100 plug-in boards with a range of functions. The whole thing became very difficult to handle, which affected both production and the supply of spare parts. A crawler crane, for example, required up to 24 different plug-in boards containing a range of functions.

Erwin Morath: The standardisation of the hydraulic and electrical control systems was another major step forward. Starting in 1986, we employed additional personnel who had the expertise to implement our concept of a modern microprocessor control system.

Our objective in terms of the software was a Liebherr multiprocessor, multitasking operating system with an integrated diagnostic system. We developed our own programming system using a simple PLC language. The software was structured and management using a parts list generation system and a database. And to ensure that the software was reproducible, we linked this system to our commercial IT system. The LMB data from the structural engineering was transferred automatically in stages.

Klaus-Peter Brück: This was a massive benefit because before then, the data had to be entered manually. That was extremely time-consuming.

Erwin Morath: In retrospect we can certainly say that we achieved our objectives. The LICCON control system was unique in the industry and could not be copied. We managed to reduce expenditure and costs as well as achieve simplifications. The important thing from the very outset was to ensure availability. We wanted to be independent from external suppliers and therefore manufactured more and more components within the Liebherr Group.

What was so special about LICCON? Did it have any unique features?

Erwin Morath: The LICCON was a universal control system which replaced everything else on the crane. It could not be copied because there were hardware components integrated in the control system whose logic we had created and programmed ourselves.

Max Leicht: The microprocessor system was a massive leap forwards. It meant that we now only had two plug-in boards. And a modern monitor. None of our competitors had a control system anything like it.

Did everything work well straight away?

Karl Münst: Actually, we hardly had any problems at all. For us in the acceptance section, it was important that we were kept up to date right from the start. That worked well because the developers worked very closely with us and spent a great deal of time outside on the crane. And we received extensive training.

Klaus-Peter Brück: In fact some very close friendships were created at that time. Our colleagues were very open and highly motivated. And we were also in close contact with customers who then worked with the prototypes. These cranes had to be repeatedly updated to the latest version. We had particularly close contacts with Uwe Langer at Riga Mainz, with whom we also discussed my idea of load capacity interpolation for intermediate lengths and who then tested the idea after it had been implemented. The idea came from my own personal experience as I grew up in a crane company.

Max Leicht: The new control system also had an influence on crane production and our colleagues first had to get used to this new technology. Many of the production processes were changed. We had to give our colleagues lots of training and support. But at the end of it all, it all worked very well.

What additional major developments were made over the years?

Erwin Morath: In the mid-90s we developed a crane job planner which enable jobs to be planned and documented on a PC in an office. The special feature of this was that the current crane data were used and the layout of the display on the monitor in the crane corresponded. The scope and benefits of our planning tool were so great that it is still pretty much the same today and is used extensively by our customers. Currently we are replacing this tool with the new Crane Planner 2.0.

Another major milestone was the development of the LSB (Liebherr System Bus) bus system, which required no hardware modifications to the central unit. It enabled the cabling to be significantly reduced and safety levels enhanced. Analogue sensors were replaced with digital ones. The sensors delivered the intelligence. That enabled us to unveil the first mobile crane in the world with a databus system at the Bauma in 1998 in the form of the LTM 1030/2.

Erwin Morath: At the end of the 90s we developed to cascading universal control units for the crane chassis which could cover all the vehicle’s functionalities. This also included a universal keyboard unit. This meant that we managed to standardise all our cranes with the same components, a massive benefit to our customers for their operators. The engine control units were included and the superstructure control unit was connected. This enabled us to make a whole host of developments on the crane chassis, such as the speed-dependent rear axle steering. The new universal control units then also provided the basis for the next LICCON2 control system generation, which we launched in 2007.

Karl Münst: Operating the crane with LICCON2 was much more convenient – the BTT control and display unit allowed the crane to be set up easily and safely. Extending the outriggers, detaching the hook block and installing the auxiliary equipment - all by remote control. Initially the BTT required a little bit of getting used to, but now nobody will consider buying a crane without it.

Klaus-Peter Brück: LICCON2 also delivers the option of a simple and therefore cost-effective extension to create a complete remote control system for the crane. In addition to the relevant software on the crane, all that is required is a console with two master switches to which the existing BTT is plugged in. A significant advantage for the crane operator is that the console can also be used for other cranes with the LICCON2 control system which are programmed for remote control. It couldn’t be any more economical.

Thank you very much for your insights into the creation of the LICCON crane control system and pioneering developments during the years that followed. Now we are about to launch the third generation, the LICCON3, which is currently undergoing an intensive phase of testing. Visitors to the Bauma in October will be able to look at two crane models featuring LICCON3.

In other words, the future has arrived.