Receiver/emitter cover utilizing active material actuation
A system for protecting an emitter/receiver device, including a cover and an active material actuator operable to selectively cause the cover to move between default protective and open positions, wherein the actuator includes at least one active material element, such as an SMA wire configured to cause the retraction of the cover and present a heating net when activated, and an activation signal source, and preferably further including at least one pulley and/or jack mechanism configured to redirect a displacement force vector, synchronization means, an antagonistic element for biasing the cover towards the protective or open position, and a controller presenting overheating protection through control logic.
1. A receiver/emitter protection system adapted to protect an engaging surface defined by a vehicle from a space or window providing access to the surface, the system comprising:
a receiver/emitter defining the engaging surface;
a housing to enclose the engaging surface wherein the housing defines the space or window;
a moveable cover configured to overlay the engaging surface so as to form superjacent layers with the engaging surface when the moveable cover is in a protective position;
an engaging prong defined along a lateral centerline of the cover;
an actuator including a thermally activated shape memory alloy (SMA) wire having a first end fixedly attached to the housing on a first side of the lateral centerline and a second end fixedly attached to the housing on a second side of the lateral centerline opposite the first side, wherein:
the SMA wire is disposed in contact with the engaging prong to bend the SMA wire at an angle;
the SMA wire defines a first leg and a second leg of an isosceles triangle with the engaging prong substantially at a first vertex of the triangle, and the first end and the second end of the wire are respectively at a second and third vertex of the isosceles triangle;
a position of the second vertex and a position of the third vertex do not move when the SMA wire is activated;
the SMA wire is operable to undergo a change in lengthwhen activated;
the SMA wire is drivenly coupled to the cover via the engaging prong such that the cover is selectively caused to move between the protective position and an open position;
the movement of the cover is an amplification of the change in length of the SMA wire;
the engaging surface is exposed to the space or window as a result of the change in length of SMA wire; and
the SMA wire is positioned relative to the cover so as to heat the cover at a predetermined location;
an activation signal source communicatively coupled to the active material element, and operable to selectively produce an activation signal; and
a pair of parallel slots defined in the housing to linearly guide the movement of the cover in a presence of an asymmetrical activation of the first leg relative to the second leg.
2. The system as claimed in claim 1 , wherein the cover is at least partially formed of shape memory polymer, so as to become malleable when activated and then re-hardened when deactivated.
3. The system as claimed in claim 1 , wherein the SMA wire is communicatively coupled to a controller, and the controller includes control logic configured to protect the SMA wire from overloading.
4. The system as claimed in claim 1 , wherein the system further comprises a controller, the actuator is operable to determine a first condition where the cover fails to move and the SMA wire is activated, and the controller is communicatively coupled to the actuator and configured to modify the activation signal when the first condition is determined.
5. The system as claimed in claim 1 , further comprising:
at least one biasing element antagonistic to the actuator and configured to bias the cover towards one of the protective and open positions, wherein the at least one biasing element is disposed within at least one of the parallel slots in the housing.
6. A receiver/emitter protection system adapted to protect an engaging surface defined by a vehicle from a space or window providing access to the surface, the system comprising:
a receiver/emitter defining the engaging surface;
a housing to enclose the engaging surface wherein the housing defines the space or window;
a moveable cover configured to overlay the engaging surface so as to form superjacent layers with the engaging surface when the moveable cover is in a protective position;
an engaging prong defined along a lateral centerline of the cover;
an actuator including an active material element having a first end fixedly attached to the housing on a first side of the lateral centerline and a second end fixedly attached to the housing on a second side of the lateral centerline opposite the first side, wherein:
the element is disposed in contact with the engaging prong to bend the element at an angle;
the element defines a first leg and a second leg of an isosceles triangle with the engaging prong substantially at a first vertex of the triangle;
the first end and the second end of the active material element are respectively at a second and third vertex of the isosceles triangle;
a position of the second vertex and a position of the third vertex do not move when the active material element is activated;
the element is operable to undergo a change in length when activated;
the element is drivenly coupled to the cover via the engaging prong such that the cover is selectively caused to move between the protective position and an open position;
the movement of the cover is an amplification of the change in length of the element; and
the engaging surface is exposed to the space or window as a result of the change in length of the element;
an activation signal source communicatively coupled to the active material element, and operable to selectively produce an activation signal; and
a pair of parallel slots defined in the housing to linearly guide the movement of the cover in a presence of an asymmetrical activation of the first leg relative to the second leg, wherein the active material element is selected from the group consisting of shape memory polymers, electroactive polymers (EAP), magnetostrictive materials, and electrostrictive materials.
7. The system as claimed in claim 6 , wherein the actuator and cover are cooperatively configured so as to cause in-plane translation by the cover, when the active material element is activated.