Design of an Elevator Control Mechanism for a Small Airplane

FOR REFERENCE SEE THE ATTACHED FILE You are asked to design a control mechanism for the elevator of a small single engine airplane, shown to scale in Figure 1. For an airplane to gain or to lose altitude in normal operating conditions, it is necessary that the pilot control the pitch motion of the airplane by changing the angle that the elevator in the tail section makes with respect to the horizontal. For this purpose, the pilot must push or pull a stick placed in front of him/her. The control mechanism that you are asked to design will transmit the motion of the stick to the elevator. When the pilot pullsthe stick, the elevator must move up in order for the airplane to pitch up and to gain altitude. When the stick is pushed, the elevator must move downward in order for the airplane to pitch down and to lose altitude. The range of motion of the pilot's arm should preferably be within 180 degrees from the horizontal x-direction for push to -120 degrees for pull (refer to Figure 2). The motion of the stick must cause the elevator to rotate -20 degrees and +20 degrees from the horizontal direction (refer to Figure 2). Note that there are areas of the airplane that are reserved for passengers, fuel tank, etc. which cannot be used for placement of the mechanism. The available space for placing the control mechanism is shown in Figure 2 as the shaded area. The drawing is to scale so that you can measure all the necessary dimensions. All the motion of the designed mechanism must be within this area. You are not allowed to use belts, chains, cables, nor pulleys. You must submit a typewritten report with a maximum of 25 pages. In this report, you must include the following information documenting your design. a) Brief description of the problem. b) Brief description of the mechanism designed. c) Drawings of your design showing all the dimensions. Illustrate graphically the range of motion. d) Outline your synthesis or design methodology -- graphical, analytical, and/or computer procedures. e) Discussion justifying your design choice and demonstrating that the mechanism meets the requirements. f) Kinematic analysis of the mechanism designed. Show pertinent information such as position, velocity and acceleration of the elevator as a function of angular displacement of the stick. If you are using a computer program, validate your results by constructing the velocity and acceleration polygons at one configuration of the mechanism. If you use graphical methods for the kinematic analysis, a minimum of three configurations must be studied. g) Dynamic (kineto-static) analysis of the mechanism designed. Choose the material and inertia properties of the links, and determine the maximum stick force that the pilot needs to develop in order to operate the elevator control mechanism you have designed. h) Prototype construction. Build a working prototype for your design and demonstrate its function. i) Limitations of your design and suggestions for further improvement. Figure 1. General drawing of a small general aviation airplane Figure 2. Scale drawing of the available area for placement and motion of the elevator control mechanism