JPH0367028A - Control apparatus of gas turbine engine - Google Patents

Abstract

PURPOSE: To eliminate discontinuation or instability of control by receiving a set of inputs by a first and a second control channels respectively, forming respective rate signals by processing the inputs, coupling them to a common integrator, and actuating an actuator by the integrator. CONSTITUTION: Both of a first and a second receiving means 20, 50 receive at least one control signal 22 indicating a desired operation level of an engine. Both of a first and a second control loops 12, 14 generate differential signals 28, 58, these differential signals form rate signals 34, 64 by processing by the respective control loops 12, 14, the rate signals 34, 64 are combined with each other by a combining means 36, and the combined signals are inputted to a common integrator 38. The integrator 38 actuates an actuator 40 of the engine. The respective control loops 12, 14 simultaneously control operation of the engine. When a failure occurs in one control loop 12 or 14, the other control loop 14 or 12 automatically compensates.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a gas turbine engine, and more specifically, to a first control device for constantly monitoring and controlling the operation of the engine.
and a control device having a second channel.

BACKGROUND OF THE INVENTION Today's gas turbine engines have numerous devices that control a wide range of parameters to achieve the most efficient engine operation. Some of these controlled parameters include fuel flow rate, fan speed, fan pitch, and fan exhaust nozzle area. Recently, fully controlled digital electronics have been used to provide increased system control over previously uncoordinated control loops. However, when such electronic equipment is used in a gas turbine engine, it is desirable to provide a support control system to ensure continued operation in the event of an electrical failure or malfunction of a part of the primary control system. . Typically, such support equipment consists of either additional hydrodynamic systems or electronic equipment, either of which takes control of the engine only after the primary control system has failed. Typically, detection of faults in the primary controller is automatically monitored through the use of built-in test (BIT) equipment. This equipment examines values, ranges, and sensors throughout the control equipment, such as random access memory (RAM), analog-to-digital converters, input buses, microprocessors, and power supply voltage values, as well as performs sample tests. This typically verifies that 95% of the controller's operation is correct. After the BIT device detects a fault, the primary controller is automatically taken offline and the support controller is activated. However, since the electronic control device must constantly monitor and control the operation of the engine, B
The IT equipment must be time-shared with the computer controller of the control unit. Therefore, this device requires an extended period of time to verify correct operation of the entire device, and thus an undesirable delay can occur before a fault is detected.

Furthermore, after a failure in the primary controller is detected, there may be a delay before the support controller becomes fully operational. Finally, typical IT! Since the j < position detects 95% of all failures, 5% of failures will not be detected and therefore the primary controller will not automatically go offline during such an undetected failure mode. The failure to detect a fault, the delay in detecting a fault, or the delay in bringing support equipment fully operational may result in interruptions or instability in engine control. V may occur, resulting in overspeed, stalling or engine flameout.Therefore, there may be a delay in detecting the fault, and even if the fault is not detected. It is desirable to provide a control device that does not cause any problems.

SUMMARY OF THE INVENTION A controller for a gas turbine engine has first and second channels that simultaneously control the engine.

A first channel receives a set of inputs and processes the inputs to form a first rate signal. A second channel also receives the same set of inputs and processes the inputs to form a second rate signal. The first and second rate signals are coupled to means for combining these signals, the output of which is coupled to a common integrator. This integrator operates the engine actuator.

The invention also provides an apparatus for controlling a gas turbine engine. The apparatus has first and second means for receiving engine control signals and first and second means for generating first and second monitor signals. First means for generating a difference signal representative of a difference between the control signal and the first monitor signal is coupled to the first means for receiving. A first means for processing the first difference signal to form a first rate signal is coupled to the first difference means. Second means for generating a second difference signal representative of the difference between the control signal and the second monitor signal is coupled to the second means for receiving. A second means for processing the second difference signal to form a second rate signal is coupled to the second difference means. Means are provided for combining the outputs of the first and second processing means, and a common integrator and actuator are coupled to the output of the combining means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a control system 10 for a gas turbine engine is generally shown. It should be appreciated that this controller is equally applicable to any gas turbine engine, such as a turboshaft, turbojet or turbofan engine.

Controller 10 has first and second control loops or channels 12.14 that simultaneously monitor and control engine operation. A first control loop 12 has first receiving means 20 for receiving a set of inputs 22 . The input is processed to generate a first error signal 24 representing a desired change in engine operation.
form. A first receiving means 20 is coupled to a first means 26 for generating a difference signal 28 representative of the difference between the first error signal 24 and a first feedback signal 30 corresponding to actuator movement. . Difference signal 28 of first difference means 26
is preferably coupled to first dynamic means 32 for processing the signal to a desired level. The signal output from the first dynamic means 32 is a first rate signal 34 representative of the desired rate of change of the parameter being controlled. The output of the first dynamic means 32 combines the signals 36, the common integrator 38 and the actuator means 4.
Combined with 0. The first control loop 12 then terminates with first means 42 for generating a first monitor signal 44 representative of the state of the actuator. Preferably, the first monitor signal 44 is connected to a first feedback processing device 46 . This processing device generates a first feedback signal 30 which is coupled to the first difference means 26 . The second control loop 14 is comprised of similar parts to the first control loop 12. That is, the second receiving means 50 receives the same set of inputs 22 as the first receiving means and similarly processes these inputs to form a second error signal 54. The set of inputs 22 received by the second receiving means 50 utilizes separate sensors, monitors and processing equipment from that used to form the set of inputs 22 received by the first receiving means 20. It is preferable that this occurs. Therefore, variations may occur between the set of inputs 22 received by the first and second receiving means 20.50 due to component failures, such as sensor failures, or due to variations in tolerances. A second means for receiving 50 is coupled to second means 56 for generating a difference signal 58 representative of the difference between the second error signal 54 and a second feedback signal 60 corresponding to actuator movement. . Preferably, a second means 56 for generating a difference signal 58 is coupled to a second dynamic means 62 for processing this signal to a desired level. The signal output from the second dynamic means 62 is a second rate signal 64 representing the desired rate of change of the parameter being controlled. The second rate signal 64 combines the signals 36, the common integrator 38 and the actuator means 4.
Combined with 0. The second control loop ends with second means 72 for generating a second monitor signal 74. The second monitor signal is coupled to a second feedback processing device 76 which generates a feedback signal 60 which is coupled to the second difference means 56. Note that the signals from each control loop are therefore combined before the common integrator 38.

The first and second receiving means 20.50 may be any means for receiving either electrical signals or mechanical signals, but the receiving means may be a digital electronic control adapted to receive electronic control signals. Preferably, it is the input port of the (DEC) device. The first and second means 26.56 for generating a difference signal may be any means for generating a signal representative of a difference between two inputs. Typically the difference signal is DE
Generated by a C computer. Furthermore, the first and second dynamic means 32.62 are preferably comprised of DECs, as is well known in the field of gas turbine engine controls. Furthermore, first and second feedback processing devices 4
When using 6.76, it is preferable that the processing be performed on a DEC device.

Means 36 for combining signals includes first and second rate signals 34
．． It is preferable to use means for averaging or adding 64 times. The common integrator may be implemented electronically or in hardware, which is preferred. The means for combining the signals 36, the common integrator 38 and the actuator 40 may be combined into one component;
Or they may be separate parts. For example, as shown in FIG. 2 in the case of a unitary fuel flow control system, a dual coil torque motor 60 may have a dual coil torque motor 60 for both first and second rate signals, depending on the type of coil. It can also act as an adder or as an averager.

A dual coil torque motor 60 can be coupled to a pilot and metering valve 62. This valve can serve as both a common integrator and actuator.

At this time, the pilot and metering valve 62 controls the actual fuel flow rate. It is preferable that the pilot and meter valves have a transfer function of /s. Here, K is a multiplier,
S is the IM prime frequency variable. Furthermore, in an integrated control system, the first and second feedback processors 46, 76 preferably have a transfer function Ks/s (T+s+1). where K is a multiplier, S is a multimodal frequency variable, and T1 is a time constant expressed by a Laplace algebra used to describe the controller's response to various inputs.

The controller may operate with rate feedback, as in the case of an integral controller, or alternatively the first and second dynamic means 32.62 may process the signals into rate signals. good.

The first and second means 42.72 for generating monitor signals are typically individual sensors of the engine.

This sensor may be of any type known to produce a proper indication of the particular parameter determined by the engine. If the fuel flow is controlled, the sensors are preferably a pair of linear differential transformers (LDVTs) that measure the position of the metering valves. As shown in FIG. 3, the proportional fuel flow control system produces a signal output that is proportional to the first and second monitor signals 44.74. first and second means 26.56 whose proportional outputs generate this post-difference signal;
is input. Preferably, the DEC device utilizes input from the position sensor and uses an algorithm to determine the rate of change of the metering valve. Note, however, that in both integral and proportional controllers, a common integrator receives a combined rate input.

To explain the operation, the first and second receiving means 2
0.40 both receive at least one control signal representative of a desired level of operation of the engine.

Both the first and second control loops 12.14 generate difference signals, which are processed separately in each control loop. The processing of each control loop forms a rate signal that is combined and input into an integrator of the combined signal that actuates the engine actuator. The loops simultaneously control the operation of the engine. Note that the term quantity means that each loop actively monitors and controls the operation of the engine. However, the control system typically Because the system is microprocessor-based, there will be some delay between each loop update and control change due to the normal clock ordering of microprocessor operations. , the signals from each channel are applied to two separate coils of a dual-coil torque motor.The torque motor then controls a pilot and metering valve that controls the flow of fuel.The position of the valve is monitored and the two corresponding signals are separately merged into each of the two control loops.To this end, the signals are input to the DEC,
There it is processed by implementing a transfer function, the result of which is applied to its own differential means, thus providing closed loop control. Therefore, each control loop generates its own command, converts that command into an appropriate current, and that current is applied to separate coils of the torque motor, which acts as a summer for both control loops. . In this device, one integrator can be used and naturally shared by two control loops. Thus, if a failure occurs in one control loop, the remaining control loops automatically compensate for any incorrect control signals applied to the dual coil torque motor. The control device of the present invention not only allows a delay in detecting a failure or a delay in fully operating the support device;
The device is capable of failures that are not detected by the built-in test equipment. If a failure occurs in one control loop, rather than the gas turbine engine becoming unstable or completely uncontrolled, the other loop takes control and compensates for the faulty equipment. For this reason, the device of the present invention is resistant to failure, and there is no problem even if it takes a longer time to detect the failure, and during this period, if the engine is controlled and support equipment is used, controls the engine during the period in which it is in operation.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of one embodiment of the present invention, FIG. 2 is a schematic diagram of an integral type control device n of another embodiment of the present invention, and FIG. 3 is a schematic diagram of a proportional type control device of the present invention. Explanation of main symbols 12.14: Channel 36: Combining means 38: Common integrator 40: Actuator

Claims (1)

Claims: 1. A first channel receiving and processing a set of inputs to form a first rate signal; and a second channel receiving and processing the same set of inputs simultaneously to form a first rate signal. a second channel for forming a rate signal of the gas; and means for combining said first and second rate signals, the output of said combining means being coupled to a common integrator, said integrator A gas turbine engine control device coupled to an actuator of the turbine engine. 2. The control device according to claim 1, wherein the common integrator and actuator are combined. 3. The control device according to claim 1, wherein said common integrator is an electronically configured integrator. 4. The control system of claim 1, wherein the first and second rate signals are combined by summing the signals. 5. The control system of claim 1, wherein the first and second rate signals are combined by averaging the signals. 6. The control system of claim 1, wherein said signal combining means is a dual coil torque motor. 7. In an apparatus for controlling a gas turbine engine, first means for receiving at least one engine control signal representative of the desired operation of the engine; and means for generating a first monitor signal representative of the actual condition of the engine. and coupled to the first means for receiving and the means for generating a first monitor signal, the first means for receiving the first engine control signal and the first monitor signal
means for generating a first difference signal output representative of a difference between the monitor signals of; and a means for processing the first difference signal; means for forming a first rate signal output; second means for receiving the control signal; and means for generating a second monitor signal representative of the actual condition of the engine; means for generating a second difference signal output representative of a difference between the control signal and the second monitor signal; means for processing the second difference signal to form a second rate signal output; and means for combining the outputs of the first and second difference signal processing means; , a common integrator and an actuator coupled to the output of the combination means. 8. The apparatus of claim 7, wherein the means for combining the outputs of said first and second processing means is a dual coil, torque, motor. 9. The apparatus of claim 7, wherein said common integrator and actuator constitute a fuel flow valve. 10. The apparatus of claim 7, wherein the means for generating the first monitor signal and the means for generating the second monitor signal are both position sensors relative to the fuel flow metering valve. 11. a first feedback processing device for processing the first monitor signal before the first monitor signal is input to the means for generating a first difference signal output; 8. The apparatus of claim 7, further comprising a second feedback processing device for processing the second monitor signal before being input to the means for generating a difference signal output. 12. The apparatus of claim 11, wherein the first and second feedback processing devices both generate a rate signal from the first and second monitor signals.