1. DISCRETE CONTROLLER DESIGN• In controller design we try to meet some objective. Typical objectives include, - positioning - for moving from position to position, where the setpoint is changed suddenly - tracking - for following paths where setpoints are constantly changing - disturbance resistant - unexpected variations can be compensated for - multi-stage - for complex systems that need small errors feed forward disturbance - can reduce effects of disturbances feed forward command - to follow complex motions cascade - a controller that examines intermediate steps of a process • typical constraints to be developed are, - stability - does not diverge over time - stability - sampling period is short enough (no-aliasing) - realizable - does not refer to future values 1.1 POSITIONING CONTROLLERS1.2 TRACKING1.3 DISTURBANCE RESISTANT1.4 MULTI-CONTROLLER SYSTEMS1.5 SAMPLE TIME1.6 SUMMARY1.7 PRACTICE PROBLEMS |