Using Real-time Java for Industrial Robot Control

In English Safe languages like Java provide a much more programmerfriendly environment than the low-level languages in which real-time and embedded software have traditionally been implemented. However, an obstacle for widespread use of Java in control applications has been the predictability and real-time performance of garbage collection, and the cumbersome memory management associated with RTSJ NoHeapRealtimeThreads. The current version of the Sun Java Real-Time System includes a real-time garbage collector, and therefore, it is interesting to examine its feasibility for robot motion control. We have implemented a motion control system, and an application, for an ABB IRB 340 industrial robot entirely in real-time Java, using standard computer hardware, off-the shelf EtherCAT servo drives, and the Sun Java Real-Time System 2.0 on Solaris 10. To our knowledge, this is the first robot control system implemented entirely in Java and executed on a certified virtual machine.