Our heavyweight helicopter equal in the world does not have
In Rostov started production of the most load-lifting rotary-wing car The Russian holding «Helicopt[...]
Autopilot
When the Wright brothers flew their first contraption, they controlled the airframe with stick and rudder. Manually they counteracted wind gusts and steered the plane on its course. By the end of World War II, the flying machines became so sophisticated that the pilot needed some help from electronic instruments. For simple flight conditions, like steady cruise over long distances, the electronics would take over completely, and with hands off, the automatic pilot would control the aircraft. Today, autopilots are found in every aircraft. Missiles, lacking the human touch, cannot fly without them. We are even now conceptualizing combat aircraft that relegate the pilot to a ground controller,
There are many good references on control theory in general and autopilots in particular. A good introduction to classical and modern control is the textbook by Dorf and Bishop,9 which uses the popular MATLAB®10 software package. Pamadi7 treats flight controllers from a classical viewpoint, whereas Steven and Lewis6 approach them from a modem angle. One of my favorite books on advanced topics is by Stengel11 addressing the stochastic effects of control. If you are fluent in German, you should consider the standard text by Brockhaus.12
Autopilots stabilize airframes, improve control response, convert guidance signals to actuator commands, and maintain constant flight parameters. They compare the commanded inputs with the measured states and shape the error signal for execution by the actuators. Figure 9.8 shows the position of the autopilot for a piloted
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Lead/Lag 1 L PI, PID V+l 7> + l
Fig. 9.9 Pseudo-five-DoF pitch plane acceleration controller for missiles (similar for yaw plane). |
aircraft (inner loop only) and for a missile (inner loop with guiding outer loop). For an aircraft the pilot sets the course; for a missile the goal is to reach a certain target state, be it for intercept, rendezvous, or specific end conditions.
The signal of the feedback loop determines the type of autopilot. A flight-path controller operates on flight-path-angle measurements. In the horizontal plane it is also referred to as heading autopilot. To hold altitude, height measurements are used in the altitude controller. A bank-angle controller executes constant turns. For missiles the acceleration controllers are particularly important because the commands from the guidance system are expressed in body accelerations.
