Flight Mechanics, Flight Control and Aeroelasticity

Active Sidestick

The department has an active sidestick, which is provided by the company Liebherr Aerospace. The sidestick is located in a functional unit in which the actuator technology for moving the sidestick, the control components required for this and the power electronics are already integrated. This functional unit is referred to by the manufacturer as the Sidestick Unit (SSU). It can be acted upon mechanically, by deflecting the sidestick by hand, and electronically, by means of digitally specified control commands. The electronic signals come from an external computer (Inceptor Control Module (ICM)). Signal transmission between the SSU and the ICM takes place via a Controller Area Network (CAN). Two electric motors operate inside the active sidestick. A distinction is made between pitch movement and roll movement. One electric motor is responsible for each of the two directions of movement.

The sidestick has an active and a passive mode. In passive mode, the built-in electric motors are switched off. In active mode, the sidestick is given any artificial feel. In addition, the sidestick can follow the inputs of another sidestick by specifying a target position. Either a position or a force5 is specified. The movement of the sidestick is interpreted as a rotation around virtual axes. In the pitch direction, the sidestick can be deflected by ±16°, in the roll direction by ±14°.

The active sidestick is integrated into a test stand which, in addition to the sidestick, contains a display unit (for displaying instruments of an aircraft cockpit) and an adjustable seat. A Simulink model is used at the test stand to send position preset signals, which takes over the task of the ICM. The Simulink model provides the signals, which are transmitted to the SSU by means of a control unit from Vector.

A display computer with an attached screen is available at the test bench (together referred to as the display unit). The display computer receives data such as attitude angle, altitude and speed of the aircraft via a UDP network. The data is displayed on a Primary Flight Display (PFD) and Navigation Display (ND).