RIPTIDE

Real-time Interactive Prototype Technology Integration/Development Environment

Use of RIPTIDE in Control System Development

Control design and analysis tools such as MATLAB/Simulink and CONDUIT enable the controls engineer to design and optimize a notional control system and ensure that all the relevant requirements are satisfied. The matching of requirements is verified in a static sense using time- and frequency-domain responses; a procedure that is satisfactory for any single control system mode. Most modern control systems, however, now employ multiple selectable modes as well as gain scheduling, switching logic, and failure compensation schemes. Evaluating these additional aspects requires the use of piloted simulation to allow dynamic transition between modes and through the various schedules and logic.

Piloted simulation evaluation of a notional control law design using a high-fidelity non-linear mathematical model has always involved a complex and lengthy integration process. The reason has been that though math models and control law design tools have been developed and improved over the years, they were never designed to work together. As a result, the integration process has not lent itself to rapid prototyping, whereby ideas can be quickly implemented and tested without significantly lengthening the development cycle.

RIPTIDE eliminates this lengthy integration process and allows notional control laws to be quickly tested and re-tested in piloted simulation. This is accomplished by treating each component of the simulation as an independent process and providing inter-process communication through a shared area of the computer memory. Also, process timing and scheduling is used to ensure that the various components of the simulation are executed in the proper order. The only requirement is for each process to be able to read from and write to the shared area of memory. Most existing software can be modified to accomplish this task and can therefore be incorporated into the RIPTIDE simulation environment. Use of CONDUIT-developed control laws is even simpler, since shared memory input/output blocks for Simulink have already been developed. This, coupled with Real Time Workshop¹s automatic code generation capability, allow CONDUIT-developed control laws to be almost immediately ready for piloted simulation in the RIPTIDE environment.