A vehicle, such as an aircraft, has a control surface 2 coupled to a main body (fig.1,1). An actuation system drives the rotation of the control surface relative to the body, having at least one pair of extensible shape memory alloy couplings 3a1,3a2,3b1,3b2. A heating system selectively heats one coupling member in response to a control input received by the actuation system, when heated each coupling member causes the control surface to articulate in opposite directions to one another. Each coupling may contract when heated, pulling a side of the control surface to which it is attached towards the main body, causing it to rotate about a pivot point (fig.2a,2b); alternatively, one end coupling end may be attached to a pivot structure 7, their other end attached to the main body, so that when heated the coupling contracts, pulling the pivoting structure towards different sides of the main body. The couplings may contain a tubular mesh of a Nickle Titanium alloy. The heating system may have a number of electrical heating elements 9a1,9a2,9b1,9b2 at one end of each coupling; or jet engine may heat a fluid which is transported in ducts close to an end of each coupling.
Control surface actuation
2025-02-05
Patent
Electronic Resource
English