System including an autopilot, with a simulator, for a fluid borne vehicle
First Claim
1. A control system for a fluid borne vehicle, described behaviorally by a set, comprising a vector, of state variables, said system including(a) vehicle controls to effect, with vehicle motion, changes to said state variables in response to control inputs,(b) measurement means to provide a set of observed state values representative of at least some state variables of the vehicle,(c) autopilot means operable(i) to simulate the behavioral response of the vehicle to values of control inputs to produce a set of values representative of estimated state variables,(ii) to observe at least the estimated state variables corresponding to the state variables observed by the measurement means, and(iii) to cause, by way of said control inputs, the vehicle to assume a steady state condition in relation to state variables observed at which motion-disturbing out-of-trim forces acting on the vehicle are compensated for, and(d) an evaluation facility responsive to relationships assumed in such a steady state condition between vehicle motion defined by the autopilot means and a set of observed estimation error values, between observed state variables and observed estimated state variables, that is attributable, in such steady state condition, to motion-disturbing out-of-trim forces to derive, from a set of instantaneously observed estimation error values, values of said motion-disturbing forces.
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Accused Products
Abstract
This invention relates to a system including an autopilot, with a simulator, for a fluid borne vehicle, and, in particular, to such a system including novel means to compute, in real time, and for depth keeping, and pitch keeping, purposes, any change of, or `out-of-trim`, heave force, and any change of, or `out-of-trim`, pitching moment, acting on the vehicle. For simplicity the general term out-of-trim forces is used when both are referred to.
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Citations
15 Claims
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1. A control system for a fluid borne vehicle, described behaviorally by a set, comprising a vector, of state variables, said system including
(a) vehicle controls to effect, with vehicle motion, changes to said state variables in response to control inputs, (b) measurement means to provide a set of observed state values representative of at least some state variables of the vehicle, (c) autopilot means operable (i) to simulate the behavioral response of the vehicle to values of control inputs to produce a set of values representative of estimated state variables, (ii) to observe at least the estimated state variables corresponding to the state variables observed by the measurement means, and (iii) to cause, by way of said control inputs, the vehicle to assume a steady state condition in relation to state variables observed at which motion-disturbing out-of-trim forces acting on the vehicle are compensated for, and (d) an evaluation facility responsive to relationships assumed in such a steady state condition between vehicle motion defined by the autopilot means and a set of observed estimation error values, between observed state variables and observed estimated state variables, that is attributable, in such steady state condition, to motion-disturbing out-of-trim forces to derive, from a set of instantaneously observed estimation error values, values of said motion-disturbing forces.
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14. A control system for a fluid borne vehicle, described behaviourally by a set, comprising a vector, of state variables, said system including
(a) vehicle controls to effect, with vehicle motion, changes to said state variables in response to control inputs, (b) measurement means to provide a set of observed state values representative of at least some state variables of the vehicle, (c) autopilot means operable (i) to simulate the behavioral response of the vehicle to values of control inputs to produce a set of estimated state variables, (i) to observe at least the estimated state variables corresponding to the state variables observed by the first measuring means, and (iii) to cause, by way of said control inputs, the vehicle to assume a steady state condition in relation to state variables observed at which motion-disturbing out-of-trim forces acting on the vehicle are compensated for, and (d) trim ballast adjustment means responsive to trim control input signals to vary the trim of the vehicle in relation to the fluid by variation in ballast and its distribution, (e) an evaluation facility responsive to a set of instantaneously observed estimation error values, between observed state variables and observed estimated state variables, to determine therefrom the values of motion-disturbing out-of-trim forces acting on the vehicle, and (f) a trim ballast adjustment interface operable to relate said derived values of out-of-trim forces to trim control input signals for such trim ballast adjustment means for elimination of said motion-disturbing out-of-trim forces.
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15. A method of estimating out-of-trim forces acting on a fluid-borne vehicle whose behavior in motion is described by a set, comprising a vector, of state variables and which vehicle includes, in addition to controls for interacting with the fluid to effect with the vehicle motion, changes to said state variables and means to observe at least some of the state variables, means to perform an autopilot function by simulating behavioral response of the vehicle to values of control inputs applied to the vehicle to provide a vector of estimated state variables, observing at least some of the estimated state variables corresponding to the observed state variables, determining the instantaneous difference between the observed state variable values and observed estimated state variable values and providing the resultant instantaneously observed estimation error vector with said control inputs for said simulation of behavioral response of the vehicle in order to reduce errors in the vector of estimated state variables and deriving from said estimated state variables from the simulation, modified in accordance with input ordered values of state variables, representing estimated state errors, control inputs for the controls and simulation, the method comprising
(i) deriving from the set of values comprising the instantaneously observed estimation error vector (YE) the values of the vector of estimated state error variables with the vehicle established in a steady state condition, (x) (ii) deriving from said values of the vector of estimated state error variables in the steady state and from the instantaneously observed estimation error vector, in accordance with relationships existing in the steady state between the vector of estimated state error variables, (x) observed estimation error vector (YE), relationship between state and estimated state variables and observed values thereof (C) and the forward velocity of the vehicle (U), an estimate of the values representing a steady state estimation error vector relating the behavior of the vehicle and simulator (XE), (iii) deriving from the values estimated for the steady state estimation error vector (XE), in accordance with relationships existing in the steady state condition between the steady state estimation error vector and behavioral parameters of the vehicle, (equation 5) a set of values representing a vector of the vehicle motion components attributable to motion-disturbing out-of-trim forces but compensated for by the autopilot in such steady state condition (D.f or Df) and (iv) deriving, from said vector of vehicle motion components attributable to motion-disturbing out-of-trim forces and constants of the vehicle relating forces acting thereon to said motion components (D), estimates to the values of motion-disturbing out-of-trim forces acting on the vehicle.
Specification