Abstract: A method for optical signaling for electrical switch control, and in addition, optical powering of the electrohydraulic servovalve by means of opto-electric conversion using solar cells with a battery backup and dual redundancy for reliability. Optical power sources are e.g., laser diode, LED, or high intensity lamp.

Abstract: A method for optical signaling for electrical switch control, and in addition, optical powering of the electrohydraulic servovalve by means of opto-electric conversion using solar cells with a battery backup and dual redundancy for reliability. Optical power sources are e.g., laser diode, LED, or high intensity lamp.

Abstract: A control system includes a dual actuator (2) and primary and secondary controllers (20, 22), each of which has two control channels. In a normal mode of operation, the primary controller (20) controls both valves (32, 38) of the actuator (2). Each primary channel generates a model signal and a monitoring signal corresponding to expected and actual operation of the actuator, respectively. The two signals from each channel are communicated to the other channel. Each channel monitors itself as well as the other channel by comparing model and monitoring signals; and is also similarly redundantly monitored by the other channel of the controller (20). Each channel independently compares its own signals with the signals from the other channel. Each of the two channels has a deactivating switch responsive to a fault status signal from either of the two channels to thereby allow deactivation of a failed channel even when the failure in such channel prevents it from deactivating itself.

Abstract: A flight control system receiving input flight control signals from a flight control computer to manipulate a flight control surface. The dual actuator has an actuating rod connected to the flight control surface, and a pair of pistons are mounted on the actuating rod in respective first and second cylinders. The flow of hydraulic fluid into and out of the first and second cylinders is controlled by the first and second electrohydraulic servovalves, respectively. The electrohydraulic servovalves are, in turn, operated by respective signals applied to a pair of actuating coils. The system includes two controllers that receive the flight control signals and apply respective output signals to the four coils of the two electrohydraulic servovalves. In one embodiment, the controllers each have a primary channel and a secondary channel which are connected to respective actuating coils of the first electrohydraulic servovalve.

Abstract: An aircraft flight control system for use with a dual or tandem hydraulic actuator coupled to a flight control surface through an actuating rod. Each half of the tandem actuator is controlled by a respective electrohydraulic servovalve. Each electrohydraulic servovalve is controlled by signals applied to either of two actuating coils. Control signals are applied to the actuating coils from three controllers. The control signals are generated as a function of the difference between the flight control signal and a feedback signal indicative of the position of the actuating rod. Each electrohydraulic servovalve includes a pair of linear variable differential transformers generating feedback signals indicative of the position of the valve stem in each electrohydraulic servovalve. The valve feedback signals are compared to each other and to reference signals corresponding to the expected value of such feedback signals in order to detect and identify malfunctions in the flight control system.

Abstract: Each wing of an aircraft carries a set of five outboard spoilers, one inboard spoiler, one inboard aileron and one outboard aileron, together constituting the lateral control surfaces for the aircraft. Each spoiler is positioned by means of a single thread electrohydraulic servoactuator. Each outboard aileron is positioned by means of a one/one fail-operational electrohydraulic servoactuator. Each inboard aileron is positioned by a two/one fail-operational, electrohydraulic servoactuator. The control system is operated by four independent electrical control signal processing channels and four independent hydraulic pressure supplies.

Abstract: Disclosed is a method of and apparatus to facilitate the operation of two servoactuators with a two/one (2/1) fail operational capability. In preferred embodiments, four signal processing channels are provided, two of which are active and directly control hydraulic servovalves which in turn controls the rate of operation of the servoactuators. Two other modeling channels produce an electrical output similar to the output expected from the servoactuator when supplied with the input to the active channel. The two actual rate indicative outputs and the two modeled rate indicative outputs are compared and deviations in one channel from the other three cause that channel to be declared a "failed" channel. Through a logical switching system, if an active channel has failed, the output of its associated model channel is connected to the servoactuator to continue operation of that actuator.