Kinematic and Power Characteristics of the Active Frameless Aircraft Control Sidestick

Abstract

The article is devoted to the actual topic of a small-sized active aircraft control sidestick design and identification of parameters that influence its energy consumption characteristics. The analysis of structural regularities of active control sidestick kinematics design is carried out. The analysis demonstrates that the disadvantage of the known frame constructions, apart from the large dimensions, is the difference in the dynamic characteristics of the channels when using the same actuators, because the mass of a frame mounted actuator is the load for a fixed base mounted actuator. According to results of the analysis, a synthesis of the active control sidestick building based on using of kinematic pairs having one degree of motion was carried out. Hinged mechanisms were used that convert rotational motion of the input link (the actuator output shaft) to the swinging motion of the output link (the control sidestick handgrip) in a single plane. When using two such actuators, so that their links are located perpendicularly and connected to each other by a lever through one-degree-offreedom rotating pairs, a kinematic scheme with two degrees of motion is obtained. As a result the kinematic scheme of an active control sidestick which don’t use a frame is offered. The frameless scheme contains two identical actuators mounted on the fixed base, at that the interference of channels is excluded. The derivation of the actuator gear ratio between the rotation angle of the actuator output shaft and the handgrip deflection angle is given. It is shown that this dependence is of a sinusoidal type and that it is close to linear in the range of the handgrip operating angles. The given results of the parametric synthesis of the control sidestick electromechanical actuator allow to determine the electric motor minimum power and the gear ratio providing the required values of torque and speed at the actuator output link. In consequence of the research of the active control sidestick specific operation modes it is shown that the electric motor power depends on the required values of the maximum speed of the handgrip movement by a pilot and on the force applied to the handgrip, as well as on the handgrip inertia moment.