Catenary Pantograph Train 99.99 Progressive Analysis and Design Problem 17. High-speed rail pantograph. Some high-speed rail systems are powered by electricity supplied to a pantograph on the train's roof from a catenary overhead, as shown in Figure P1.9. The force applied by the pantograph to the catenary is regulated to avoid kiss of contact due to excessive transient motion. A proposed method to regulate the force uses a closed-loop feedback system, whereby a force, Fup, is applied to the bottom of the pantograph, resulting in an output force ap- plied to the catenary at the top. The contact between the head of the pantograph and the catenary is represented by a spring. The output force is proportional to the displacement of this spring, which is the difference between the catenary and pan- tograph head vertical positions (O'Connor, 1997). Draw a functional block diagram showing the following signals: the desired output force as the input; the force, Fup applied to the bottom of the pantograph; the difference in displacement between the catenary and pantograph head: and the output contact force. Also, show blocks representing the input transducer, controller, actuator generating Fup. pantograph dynamics, spring described above, and output sensor. All forces and displacements are measured from equilibrium.