The platform itself is placed on a spring-damper suspension. When a walking person is carrying this steady-cam system, the walking will cause the suspension base to move vertically. We model this perturbation to the suspension base as a disturbance input d(t). The disturbance is the input to the system. The system output is defined to be the vertical displacement x2 of the camera. Intuitively, the disturbance d(t) will cause the camera to move vertically, so you don't have a steady cam! We would like to simulate