Question 2.34: Telescope drive signal...

In order to track the motion of the stars large telescopes are usually driven by an electric motor. The speed ofthis motor is controlled in order that the angular position ofthe telescope follows a specified trajectory with time. The whole assembly, including telescope, gears, motor, controller and sensors, forms a position control system or servo-system. This servo-system must be fed a signal corresponding to the desired trajectory of the system. Often this trajectory is a ramp function as illustrated in Figure 2.46. The drive motor is started at time t = t_0 and the desired angular position of the telescope is θ.