01/18/2023 Interview: Back to the future – the development of the LICCON crane control system
LICCON, that is over 30 years of Liebherr history: with the latest generation of crane control for mobile cranes, LICCON3, Liebherr is ready for the future. But how did this crane control system come to be developed? We invited four experts for an interview, three of whom were present at the birth of LICCON in 1985.
Meeting of the generations: During the joint discussion, the Liebherr experts provided insights behind the scenes of the three generations of LICCON crane control.
"Mobile cranes operate for more than 30 years. So the control system must be durable and spare parts must be available. That was always an important aspect for us."
Erwin Morath - Head of Control System Department (retired)
"The LICCON control system was unique and provided inspiration for developments on mobile cranes."
Max Leicht - Head of Electrical Department (retired)
"The sensitivity of the crane movements is perfect with the LICCON control system."
Karl Münst - Crane Acceptance Department manager (retired)
"We have laid the foundations for the future in the form of LICCON."
Klaus-Peter Brück - Control System Software Developer
The first LICCON control system with a tube monitor
1988 prototype - LTM 1035 with LICCON control system
The first standard crane with LICCON, the LTM 1120 as from 1989
The Liebherr experts know the LICCON crane control system like the back of their hands. Three of them are already in well-earned retirement: Erwin Morath built up the control department at Liebherr's Ehingen plant and headed it for decades. Max Leicht was the long-serving head of the electrical department and a specialist in production and assembly. And Karl Münst comes from crane practice, as he was responsible for the acceptance of mobile cranes for half his life. Klaus-Peter Brück completes the circle. While still a student, he wrote his diploma thesis on the introduction of the LICCON control system (Liebherr Computed Control) and now works as a software developer for control systems.
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.
When was this and how did the development process take place?
Erwin Morath: We took the first steps in 1985. We reduced and revised the existing analogue plug-in boards and developed programmable digital plug-in boards to replace them.
Max Leicht: That was enormously important to ensure we could continue to manufacture cranes. We were able to reduce the number of plug-in boards to just 20 – a massive step forward.
Klaus-Peter Brück: In the development of a new crane control system, therefore, one of the main objectives was to establish and retain the expertise we had within the company. What we needed was a flexible control system which we could extend and expand ourselves within Liebherr.
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.
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