The article explores how positive position feedback (PPF) controllers can be designed to control vibrations in structures effectively. PPF controllers have a quick frequency response, making the system robust against instability caused by unaccounted modes. The researchers show that PPF controllers can be formulated as output feedback controllers, using optimal control methods. This approach allows for the design of PPF controllers using existing control design algorithms for output feedback systems. The study demonstrates this method on a single-degree-of-freedom system.