Control system actuation fault monitoring
First Claim
1. A method for monitoring and detecting failures in the actuation of a control system, the method comprising:
- defining a nominal model of the control system in terms of the state variables of the control system;
defining a model of an asymmetric actuation monitoring envelope that dynamically bounds a range that measured state variables of the system are allowed to take during operation of the system as a function of the nominal system state model, the monitoring envelope including a first subsystem defining an upper bound of the monitoring envelope and a second subsystem defining a lower bound of the monitoring envelope, each subsystem comprising a closed loop feedback system including a system loop closure, a fast system dynamics model, a slow system dynamics model, a switch, a system non-linearity model, a system lumped tolerances model and a signal saturation model;
and using a processor;
selecting between the respective fast and slow system dynamics models of the subsystems with the respective switches thereof so as to define the maximum permissible monitoring envelope upper and lower bounds as a function of variations in the respective system dynamics and non-linearity models of each subsystem during system operation;
monitoring a signal corresponding to a state variable of the system during operation thereof; and
,detecting a failure in the actuation of the control system when the monitored signal exceeds the bounds of the monitoring envelope.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and apparatus for monitoring and detecting failures in the actuation of a control system, such as a flight control system for an aircraft, include defining a nominal model of the control system in terms of the state variables of the control system, defining a model of an asymmetric “actuation monitoring envelope” that dynamically bounds a range that measured state variables of the system are allowed to take during operation of the system as a function of the nominal system state model, monitoring a signal corresponding to a state variable of the system during operation thereof, and detecting a failure in the actuation of the control system when the monitored signal exceeds the bounds of the monitoring envelope.
7 Citations
20 Claims
-
1. A method for monitoring and detecting failures in the actuation of a control system, the method comprising:
-
defining a nominal model of the control system in terms of the state variables of the control system; defining a model of an asymmetric actuation monitoring envelope that dynamically bounds a range that measured state variables of the system are allowed to take during operation of the system as a function of the nominal system state model, the monitoring envelope including a first subsystem defining an upper bound of the monitoring envelope and a second subsystem defining a lower bound of the monitoring envelope, each subsystem comprising a closed loop feedback system including a system loop closure, a fast system dynamics model, a slow system dynamics model, a switch, a system non-linearity model, a system lumped tolerances model and a signal saturation model; and using a processor; selecting between the respective fast and slow system dynamics models of the subsystems with the respective switches thereof so as to define the maximum permissible monitoring envelope upper and lower bounds as a function of variations in the respective system dynamics and non-linearity models of each subsystem during system operation; monitoring a signal corresponding to a state variable of the system during operation thereof; and
,detecting a failure in the actuation of the control system when the monitored signal exceeds the bounds of the monitoring envelope. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. Apparatus for monitoring and detecting failures in the actuation of a control system, the apparatus comprising:
-
a nominal model of the control system defined in terms of the state variables of the control system; a model of an asymmetric actuation monitoring envelope that dynamically bounds a range that measured state variables of the system are allowed to take during operation of the system defined as a function of the nominal system state model, the monitoring envelope including a first subsystem defining an upper bound of the monitoring envelope and a second subsystem defining a lower bound of the monitoring envelope, each subsystem comprising a closed loop feedback system including a system loop closure, a fast system dynamics model, a slow system dynamics model, a switch, a system nonlinearity model, a system lumped tolerances model and a signal saturation model; means for selecting between the respective fast and slow system dynamics models of the subsystems with the respective switches thereof so as to define the maximum permissible monitoring envelope upper and lower bounds as a function of variations in the respective system dynamics and non-linearity models of each subsystem during system operation; means for monitoring a signal corresponding to a state variable of the system during operation thereof; and
,means for detecting a failure in the actuation of the control system when the monitored signal exceeds the bounds of the monitoring envelope. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A method for monitoring and detecting failures in the actuation of an aircraft control system, the method comprising:
-
defining a nominal model of the control system in terms of the state variables thereof; defining a model of an asymmetric actuation monitoring envelope that accounts for the dynamics and non-linearities of each element of the control system and the respective variations occurring therein during system operation, and that dynamically bounds a range that measured state variables of the system are allowed to take during operation of the system as a function of the nominal system state model, the monitoring envelope comprising first and second envelope subsystem models respectively defining upper and lower bounds of the monitoring envelope, each subsystem model comprising a closed loop feedback system, including a system loop closure, a fast system dynamics model, a slow system dynamics model, a switch, a system non-linearity model, a system lumped tolerances model and a signal saturation model; and using a processor; selecting between the respective fast and slow system dynamics models of the subsystems with the respective switches thereof so as to define the maximum permissible monitoring envelope upper and lower bounds as a function of variations in the respective system dynamics and non-linearity models of each subsystem during system operation; delaying a signal input to the respective slow systems dynamic model of each sub-module by at least two signal sample periods; monitoring a signal corresponding to a state variable of the system during operation thereof; and
,detecting a failure in the actuation of the control system when the monitored signal exceeds the bounds of the monitoring envelope. - View Dependent Claims (18)
-
-
19. Apparatus for monitoring and detecting failures in the actuation of an aircraft control system, the apparatus comprising:
-
a nominal model of the control system defined in terms of the state variables thereof; a model of an asymmetric actuation monitoring envelope that accounts for the dynamics and non-linearities of each element of the control system and the respective variations therein during system operation and that dynamically bounds a range that measured state variables of the system are allowed to take during operation of the system defined as a function of the nominal system state model, the monitoring envelope comprising first and second envelope subsystem models respectively defining upper and lower bounds of the monitoring envelope, each subsystem model comprising a closed loop feedback system, including a system loop closure, a fast system dynamics model, a slow system dynamics model, a switch, a system non-linearity model, a system lumped tolerances model and a signal saturation model; means for selecting between the respective fast and slow system dynamics models of the subsystems with the respective switches thereof so as to define the maximum permissible monitoring envelope upper and lower bounds as a function of variations in the respective system dynamics and non-linearity models of each subsystem during system operation; means in each of the respective system loop closures of each subsystem for delaying a signal input to the respective slow systems dynamic model thereof by at least two signal sample periods. means for monitoring a signal corresponding to a state variable of the system during operation thereof; and
,means for detecting a failure in the actuation of the control system when the monitored signal exceeds the bounds of the monitoring envelope. - View Dependent Claims (20)
-
Specification