Abstract:
A system for controlling actuators within a gas turbine engine according to an exemplary aspect of the present disclosure includes an electronic engine controller, a plurality of actuators, and a central control unit. The central control unit includes an actuator control unit electrically coupled to the electronic engine controller and a plurality of actuator control modules. Each of the actuator control modules is electrically coupled to each of the plurality of actuators. A method is also disclosed.

Description:
BACKGROUND 
       [0001]    Gas turbine engines are known to include a compressor section, a combustion section, and a turbine section. Generally, air is compressed in the compressor section, directed to the combustor section where it is combined with fuel and combusted, and then expanded in the turbine section. Various systems associated with the engine include independently controlled actuators. The actuators receive commands from an electronic engine controller (EEC). Some example systems include variable area nozzles, stator vane assemblies, and bleed valves, to name a few. 
         [0002]    In some known engines, each actuator includes a linear variable differential transformer (LVDT) configured to provide actuator position information directly to the EEC. The actuators may further be fluidly coupled to a source of fuel, and incorporate a fuel-based hydraulic system (sometimes called a “fueldraulic” system). 
         [0003]    Each actuator further includes separate, dedicated functions within each actuator for electric, fuel, and control. Each actuator is configured to interpret instructions from an engine control system and provide corresponding feedback. 
       SUMMARY 
       [0004]    A system for controlling actuators within a gas turbine engine according to an exemplary aspect of the present disclosure includes an electronic engine controller, a plurality of actuators, and a central control unit. The central control unit includes an actuator control unit electrically coupled to the electronic engine controller and a plurality of actuator control modules. Each of the actuator control modules is electrically coupled to each of the plurality of actuators. A method is also disclosed and claimed. 
         [0005]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The drawings can be briefly described as follows: 
           [0007]      FIG. 1  schematically illustrates an example system according to this disclosure. 
           [0008]      FIG. 2  schematically illustrates an example actuator. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]      FIG. 1  illustrates an example actuator control system  20  (“system  20 ”). In this example, the system  20  generally includes an electronic engine controller (EEC)  22 , a plurality of actuators  24 A- 24 N, and a central control unit  26 . 
         [0010]    In one example, the EEC  22  is a digital computer included within a full authority digital engine controller (FADEC) F within a gas turbine engine G. The details of the gas turbine engine G are as known. In this example, the EEC  22  ultimately provides instructions to the central control unit  26 , which is, in turn, capable of bringing about changes in the operating conditions of the actuators  24 A- 24 N. It should be understood that the EEC  22  may be any known type of controller including memory, hardware, and software. The EEC  22  is configured to store instructions and to provide instructions to the various components of the system  20 . 
         [0011]    The actuators  24 A- 24 N are illustrated schematically. In  FIG. 1 , only three actuators  24 A,  24 B, and  24 N are illustrated. It should be understood that the system  20  could include a different number of actuators, each of which could be associated with a different system within a gas turbine engine. For example, the actuator  24 A may be an actuator associated with a variable area nozzle V of the gas turbine engine G and configured to adjust a position of the flaps of the variable area nozzle to adjust the area of the nozzle of the engine G. The actuator  24 B may be an actuator associated with a stator vane assembly S, and configured to adjust a position of one or more stator vanes within the engine G. The actuator  24 N may be associated with a bleed valve assembly B, and configured to adjust the position of a bleed valve of the engine G. 
         [0012]    The central control unit  26  includes an actuator control unit  28  which is electrically coupled directly to the EEC  22 . The central control unit  26  further includes a plurality of actuator control modules  30 ,  32 ,  34 , each of which is electrically coupled to each of the actuators  24 A- 24 N. The central control unit  26 , like the EEC  22 , may be any known type of controller including memory, hardware, and software. In this example, the central control unit  26  is a separate unit (e.g., embodied on a separate computing device) from the EEC  22 . 
         [0013]    The central control unit  26  is configured to store instructions and to provide instructions to the various components of the system  20 , namely the EEC  22  and the actuators  24 A- 24 N. The actuator control unit  28  and each of the actuator control modules  30 ,  32 ,  34  may be software applications embodied on the central control unit  26  and/or include electrical components necessary to perform the function described herein. 
         [0014]    In this example, the actuator control modules  30 ,  32 ,  34  include a power conditioning module  30 , an actuator position module  32 , and a drive module  34 . Each of the actuator control modules  30 ,  32 ,  34  are electrically coupled to each of the plurality of actuators  24 A- 24 N in parallel, by way of a bus  36 . For instance, the power conditioning module  30  is electrically coupled directly to the bus  36  by at least one first wired connection  30 W 1 , and is electrically coupled directly between the bus  36  and each of the actuators  24 A- 24 N by individual wired connections  30 W 2 - 30 W 4 . The actuator position module  32  and the drive module  34  are also directly connected to the bus  36  (via wired connections  32 W 1 ,  34 W 1 ) and each of the actuators  24 A- 24 N (via wired connections  32 W 2 -W 4 ,  34 W 2 -W 4 ). While wired connections are specifically contemplated herein, the connections could be wireless. Further, the bus  36  may be provided by wired connections using various protocols and signal types (e.g., microwaves). 
         [0015]    The power conditioning module  30 , the actuator position module  32 , and the drive module  34  are each electrically coupled to the actuator control unit  28 . Each of the modules  30 ,  32 ,  34  is configured to respond to commands from the actuator control unit  28 , and to relay information to the actuator control unit  28  during operation. The actuator control unit  28  is configured to interpret commands from the EEC  22 , and is further configured to relay information back to the EEC  22  from the modules  30 ,  32 ,  34  and the actuators  24 A- 24 N. 
         [0016]    The power conditioning module  30  includes a known type of power conditioner electrically coupled to at least one electrical power source. In this example, first and second power sources  38 ,  40  are coupled to the power conditioning module  30 . The first power source  38  may be aircraft power (such as a generator located on the engine gearbox or shaft), and the second power source  40  may be another power source, such as Permanent Magnet Alternator (PMA) power. The power conditioning module  30  is configured to select an appropriate one of the power sources  38 ,  40 , or to blend power from each source. The power conditioning module  30  is further configured to deliver conditioned electrical power to each of the plurality of actuators  24 A- 24 N consistent with the instructions from the actuator control unit  28 . The power conditioning module  30  provides steady, continuous power at correct levels to the actuators  24 A- 24 N, and, in doing so, may perform functions such as filtering, converting, and switching. 
         [0017]    The actuator position module  32  is configured to determine the position of each of the actuators  24 A- 24 N. In  FIG. 2 , one of the actuators  24 A is illustrated schematically. As illustrated, the actuator  24 A includes a piston  42  moveable within a cylinder  44  in a generally forward and backward translation direction T. The piston  42  in this example is driven by a motor  46  having a rotor  48  and a stator  50 . Rotation of the motor  46  is converted into translation of the piston  42  by way of a gearbox  52 . The actuator  24 A may also include a brake configured to maintain position of the piston  42 . It should be understood that this disclosure is not limited to piston-cylinder-type actuators. Other types of actuators, such as rotary actuators, come within the scope of this disclosure. 
         [0018]    In the illustrated example, the piston  42  acts as a moveable target representative of the position of the actuator  24 A. In this example, the actuator position module  32  is electrically coupled to each actuator  24 A by way of a cable  54  (represented in  FIG. 1  as wired connections  32 W 1 -W 4 ), which may be a coaxial cable in some examples. The cable  54  is configured to transmit a wave, such as a microwave, along the cable  54  to a wave guide  56  within the actuator  24 A. 
         [0019]    The wave guide  56  is arranged to direct waves  58  toward the piston  42 . The waves  58  are reflected off of the moveable target  42  and returned to the wave guide  56 . The waves  58  are then directed back to the actuator position module  32  by way of the cable  54 . The actuator position module  32  is configured to determine the position of the piston  42  based on the delay between generation and return of the waves  58 . While cables  54  and wave guides  56  are illustrated, it should be understood that the position of the actuators  24 A- 24 N may be monitored using other techniques. 
         [0020]    The actuator position module  32  is configured to relay actuator position information to the actuator control unit  28 , which is in turn configured to send this information to the EEC  22 . The EEC  22  is programmed to send corresponding instructions back to the actuator control unit  28  based on the recorded position of the actuators  24 A- 24 N, among other variables. 
         [0021]    As shown in  FIG. 2 , each of the actuators may include a motor  46 . The drive module  34  is configured to provide commands to each of the motors  46  associated with each actuator  24 A- 24 N to adjust the operating conditions of the motors  46 . Example instructions include the speed, rotational position, and rotational direction of the motor. The drive module  34  is further configured to receive feedback from each of the motors  46  to monitor their operating status, and to report the same to the actuator control unit  28 . The drive module  34  is further configured to use the motor&#39;s rotational position for motor commutation. 
         [0022]    Since the actuators  24 A- 24 N are in direct communication with the central control unit  26 , there is no need for each actuator  24 A- 24 N to include its own control unit or its own individual control modules, such as a power conditioning module, an actuator position module (which may or may not have included an LVDT), or a drive module. Instead, the actuators  24 A- 24 N essentially “share” the common modules provided in the central control unit  26 . The various commands and feedback are multiplexed sequentially, in parallel or a combination, in each of these modules  30 ,  32 ,  34 , to each of the plurality of actuators  24 A- 24 N. This reduces the complexity, cost, and weight associated with each of the actuators  24 A- 24 N. This further leads to significant reduction in weight in the gas turbine engine, as well as simplifying the overall construction and ease of manufacturing the actuators  24 A- 24 N. 
         [0023]    Although the different examples have the specific components shown in the illustrations, embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from one of the examples in combination with features or components from another one of the examples. 
         [0024]    One of ordinary skill in this art would understand that the above-described embodiments are exemplary and non-limiting. That is, modifications of this disclosure would come within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.