The Chimera II real-time operating system for advanced sensor-based control applications

The Chimera II has been designed as a local operating system, to be used in conjunction with a global operating system. It executes on one or more single board computers in a VMEbus-based system. Advanced sensor-based control systems are both statistically and dynamically reconfigurable. As a result, they require many special features, which are currently not found in commercial real-time operating systems. Several design issues for such systems are presented as well as the features the authors have developed and implemented as part of Chimera II. These features include: a real-time kernel with dynamic scheduling, global error handling, user signals, and two levels of device drivers; an enhanced collection of interprocessor communication mechanisms, including global shared memory, spin-locks, remote semaphores, priority message passing, global state variable tables, multiprocessor servo task control, and host workstation integration; and several support utilities, including a UNIX C and math libraries, a matrix library, a command interpreter library, and a configuration file library