Active Oscillation Damping of the Fire-Rescue Turntable Ladder

This paper deals with the active oscillation damping of the fire-rescue turntable ladder with a payload at the vertical plane. Because of the large length (25-50 m) the mathematical model of the ladder corresponds to a distributed parameter system. The payload at the end of the ladder is modeled by a concentrated end mass (lumped parameter system). The concept of the Euler-Bernoulli beam with the special boundary conditions describing the dynamics of the concentrated mass are proposed for the mathematical model of this hybrid system. The eigenfunctions of the corresponding boundary value problem were obtained analytically. Based on the analytical form of the eigenfunctions the modal description of the plant was constructed. For active oscillation damping by feedback without a dynamical observer the ladder was equipped additionally to strain gauges with a gyroscope. The designed feedback with the sensor signals allows to damp the fundamental oscillation as well as the first dominant overtone and asymptotically stabilize the plant with respect to its equilibrium. Some numerical simulations are included and demonstrate the efficiency of the proposed approach.