AIRCRAFT STRIKE ASSURANCE SYSTEM

• US 3,612,837 A
• Filed: 04/30/1969
• Issued: 10/12/1971
• Est. Priority Date: 04/30/1969
• Status: Expired due to Term

• Current Assignee: William E. Brandau
• Original Assignee: William E. Brandau
• Inventors: Brandau, William E.
• Primary Examiner(s): Morrison, Malcolm A.
• Assistant Examiner(s): Dildine, Jr., R. Stephen
• Application Number:
  US04/820,428
• Time in Patent Office: 895 Days
• Field of Search: 235/150.2,150.21,150.26,150.27 73/178
• US Class Current: 701/3
• CPC Class Codes: G06G 7/70 for vehicles, e.g. to determine permissible loading of ships , centre of gravity, necessary fuel

Abstract

A system for computing all necessary flight commands for successfully completing a mission, including a forecast of fuel reserves and time to each target from planned parameters by combining fuel management data and inertial navigation data. The system provides for primary and alternate targets and is adaptable to inflight mission alterations and unforeseen events such as weather changes and engine failure.

Claims

1. Strike Assurance System for an aircraft assigned to a mission having specified targets, comprising:

a navigational subsystem for providing signals corresponding to navigational commands necessary to complete the mission;

a fuel management subsystem for providing signals corresponding to optimum flight parameters; and

computing means connected to the navigational and fuel management subsystems and responsive to the signals therefrom for providing output signals to determine if the mission may be successfully completed.

2. A system as described in claim 1, in which the computing means provides a signal corresponding to a forecast of fuel reserves to determine if enough fuel is available to complete the mission.

3. A system as described in claim 2, additionally comprising indicating means responsive tO the reserve fuel signal for indicating the reserve fuel.

4. A system as described in claim 2, in which:

the navigational subsystem provides signals corresponding to range to each target, target bearing and actual wind velocity and direction; and

the fuel management subsystem provides signals corresponding to optimum airspeed and fuel weight.

5. A system as described in claim 1, in which the computing means provides a signal corresponding to time to each target to determine if the mission can be completed within a required time.

6. A system as described in claim 5, in which:

the navigational subsystem provides signals corresponding to range to each target, target bearing and actual wind velocity and direction; and

the fuel management subsystem provides signals corresponding to optimum airspeed and fuel weight.

7. A system as described in claim 5, additionally comprising indicating means responsive to the time to target signals for indicating the time to each target.

8. A system as described in claim 1, additionally comprising signal means for providing signals corresponding to planned mission parameters, the navigational and fuel management subsystems being connected thereto and responsive to the signals therefrom.

9. A system as described in claim 8, in which the signal means additionally includes means for providing signals corresponding to actual flight parameters so that the computing means updates the output signals during flight.

10. A system as described in claim 9, in which the fuel management subsystem additionally comprises:

means for providing a signal corresponding to an engine failure; and

means responsive to the engine failure signal for causing the fuel management subsystem to provide signals corresponding to optimum flight parameters with one engine failed.

11. A system as described in claim 1, in which the fuel management subsystem provides signals corresponding to optimum flight parameters to obtain maximum range.

12. A system as described in claim 11, additionally comprising:

means for providing a signal corresponding to a range trade off for additional airspeed; and

means responsive to the range trade off signal for compensating the computing means output signals for the effects of increased airspeed.

13. A system as described in claim 1, in which the fuel management subsystem provides signals corresponding to optimum flight parameters to obtain maximum endurance.

14. A system as described in claim 1, in which the optimum flight parameter signals provided by the fuel management subsystem comprise signals corresponding to optimum altitude and airspeed.

15. A system as described in claim 14, additionally comprising means for interrogating the computing means to determine the effects of flying at an alternate altitude.

16. A system as described in claim 14, in which the airspeed signal corresponds to mach number.

17. A system as described in claim 1, additionally comprising means responsive to the navigational command signals and the optimum flight parameter signals for indicating the navigational commands and the optimum flight parameters.

18. A system as described in claim 1, in which:

the navigational subsystem provides signals corresponding to range to each target, present position, target bearing, actual heading, heading command and actual wind velocity and direction;

the fuel management subsystem provides signals corresponding to optimum altitude, optimum airspeed, fuel weight fuel sight warning and improper fuel consumption; and

the computing means provide signals corresponding to reserve fuel and time to each target.

19. A system as described in claim 18, additionally comprising means responsive to the signals for indicating reserve fuel, time to each target, range to each target, present position, target bearing, actual heading, heading command, actual wind velocity and direction, optimum altitude, optimum airspeed, fuel weight, fuel weight warning and improper fuel consumption.

20. A Strike Assurance System for an aircraft assigned to a mission having specific mission points, namely, point of departure, targets and destination, forming mission segments, comprising:

a mission definition panel having means for providing signals corresponding to mission point locations, planned altitude and estimated wind conditions for each segment;

a control panel having means for providing signals corresponding to a airframe weight and point engage commands;

signal means for providing signals corresponding to total fuel weight fuel flow, inertial position, inertial ground speed, actual altitude, true airspeed and actual heading;

computing means connected to the mission definition panel, the control panel and the signal means and responsive to the signals therefrom for providing signals corresponding to optimum altitude and mach number for maximum efficiency, reserve fuel weight, time to each point and heading command for each segment; and

indicating means responsive to the signals from the computing means for indicating optimum altitude and mach number for maximum efficiency, reserve fuel weight actual heading, time to each point and heading command.

21. A STRIKE Assurance system for an aircraft assigned to a mission having specific mission points, namely point of departure, targets and destination, forming mission segments, comprising;

;

a mission definition panel having means for providing signals corresponding to mission point locations, planned altitude, estimated wind conditions, high speed range trade off, engine failure, weapon deployment and wing tank release for each segment;

a control panel having means for providing signals corresponding to airframe weight, point engage commands;

signal means for providing signals corresponding to total fuel weight, fuel flow, inertial position, inertial ground speed, actual altitude, true airspeed and actual heading;

computing means connected to the mission definition panel, the control panel and the signal means for receiving the signals therefrom and responsive to the signals for providing signals corresponding to present position, range for each segment, time to each point, optimum altitude and mach number for maximum range, total fuel weight, reserve fuel weight, actual wind velocity and direction for the engaged segment, bearing and heading command for each segment and actual heading for the engaged segment;

an altitude indicator connected to the computing means and responsive to the optimum altitude signal for providing an indication of the optimum altitude;

an airspeed indicator connected to the computing means and responsive to the mach number signal for providing an indication of the optimum mach number;

a position indicator connected to the computing means and responsive to the present position signals and range signals for indicating the present position and the range to each point;

an indicator connected to the computing means and responsive to the total fuel weight signal, reserve fuel weight signal and the time signals for indicating the total fuel weight, reserve fuel weight and time to each point; and

a heading command indicator connected to the computing means and responsive to the target bearing, heading command, actual heading, actual wind velocity and wind direction signals for indicating target bearing, heading command, actual heading, actual wind velocity and wind direction for the engaged segment.

22. A system as described in claim 21, in which the computing means additionally comprises means for providing signals corresponding to optimum altitude and mach number for maximum endurance.

23. A system as described in claim 22, in which the control panel additionally includes means for selecting an indication of optimum altitude for maximum range or maximum endurance on the altitude indicator.

24. A system as described in claim 21, additionally comprising means for detErmining the effect on the reserve fuel indication caused by reversing target sequence.

25. A system as described in claim 21, additionally comprising means for determining the effects of scrubbing a target on the reserve fuel indication.

26. A system as described in claim 21, additionally comprising means for determining the effects of flying at an alternate altitude on the reserve fuel and time to target indication.

27. A system as described in claim 21, additionally comprising means responsive to the fuel flow signal for providing an indication of improper fuel consumption.

28. A system as described in claim 21, additionally comprising means responsive to the fuel weight signal for providing a fuel weight warning signal.

29. A Strike Assurance System as described in claim 21, in which the computing means comprises:

a navigational subsystem connected to the mission definition panel, the control panel and the signal means for receiving the mission point location signals, the estimated wind signals, the point engage commands, the inertial position and ground speed signals, planned airspeed signals and the true airspeed and heading signals for providing signals corresponding to range for each segment, air range for each segment, bearing and heading command for each segment, actual heading, wind velocity and wind direction for the engaged segment; and

a fuel management subsystem connected to the navigational subsystem, the control panel, the signal means and the mission definition panel and receiving the planned altitude, actual altitude, range trade off, weapon deployment, wing tank release, airframe weight total fuel weight, fuel flow, ambient temperature and target and destination engage commands for providing signals corresponding to time to each point, optimum altitude and mach number for maximum range, total fuel weight, reserve fuel weight and planned airspeed. 30 A system as described in claim 29, in which the navigational subsystem includes means responsive to a signal indicating a failure of the inertial signals for combining the estimated wind signals, the true airspeed signal and the actual heading signal to provide a ground speed signal and integrating the ground speed signal over elapsed time to provide a standby present position signal for use in place of the inertial position signal.

31. A system as described in claim 29, in which the mission point location signals and the inertial position signals are signals corresponding to longitude and latitude of the mission points and the inertial position.

32. A system as described in claim 31, in which the navigational subsystem comprises:

a first switching means receiving the signals corresponding to longitude and latitude of the mission points and the inertial position and responsive to the engage commands for substituting the inertial position signal for a mission point signal when a subsequent mission point is engaged and having outputs providing the mission point and inertial position signals;

servo means connected to the outputs of the first switching means and responsive to the signals therefrom for providing mechanical displacements corresponding to the latitudes of the inertial position and subsequent mission points, a displacement corresponding to a difference between the longitude of the inertial position and the longitude of the subsequent point and displacements corresponding to differences in longitudes of subsequent segments;

resolver chains for each segment connected to the servo means and responsive to the mechanical displacements for providing signals corresponding to bearing and range for the mission segments;

means receiving the inertial ground speed signals, the heading signal and the true airspeed signal for resolving the airspeed signal into north-south and east-west components and subtracting the components from the inertial ground speed signals to provide signals corresponding to the components of the wind velocity;

means receiving The wind velocity component signals for combining the component signals and providing signals corresponding to wind velocity and direction;

a second switching means receiving the wind velocity component signals, the true airspeed signal, the planned airspeed signals, and the estimated wind condition signals and having outputs providing signals corresponding to planned airspeed and estimated wind conditions for each mission segment, the switching means responsive to the engage commands for substituting the actual airspeed signal in place of the planned airspeed signal and the wind velocity component signals for the estimated wind condition signals for the engaged mission segment; and

computing means for each segment connected to the second switching means and the corresponding segment resolver chain and responsive to the bearing, range, airspeed and wind component signals for providing signals corresponding to segment heading command and segment air range.

33. A system as described in claim 32, in which the computing means comprises:

an airspeed resolver having a rotor excited by the airspeed signal and positioned to correspond to a heading command and stators receiving the wind component signals and having signals induced therein corresponding to airspeed components whereby the wind and airspeed components are added to provide signals corresponding to ground speed components;

a ground speed resolver has stators connected to the stators of the airspeed resolver and excited by the ground speed component signals therefrom and a first rotor positioned in accordance with the bearing signal has induced therein a signal corresponding to an error between the bearing signal and the ground speed components a motor drivably connected to the rotor of the ground speed resolver and responsive to the error signal to adjust the heading command so that the ground speed component signals correspond to the target bearing;

a second rotor positioned at right angles to the first rotor of the ground speed resolver having a voltage induced therein corresponding to ground speed;

a first potentiometer excited by the airspeed signal and having a wiper positioned in accordance with the range signal from the resolver chain and providing a signal corresponding to the product of ground range and airspeed;

a second potentiometer connected to the second rotor and excited by the signal therefrom and having a wiper providing a signal corresponding to the product of the wiper position and ground speed; and

a servo means connected to the wipers of the first and second potentiometers for comparing the signals therefrom and positioning the wiper of the second potentiometer so that the wiper signals are equal whereby the wiper position of the second potentiometer corresponds to the segment air range.

34. A system as described in claim 29, in which the fuel management subsystem comprises:

means responsive to the fuel flow signals for providing signals corresponding to present fuel weight, means responsive to the airframe weight, weapon deployment and wing tank release signals for providing signals corresponding to total dry weight for each segment;

computing means for each segment responsive to the planned altitude, actual altitude, segment air range, ambient temperature, a calibrated excitation voltage, total fuel weight at the beginning of the segment, dry aircraft weight and range trade off signals for the associated segment for providing signals corresponding to mach bias, planned airspeed, specific range loss, present gross weight, segment time, total fuel at the segment destination and gross weight divided by density ratio;

means responsive to the gross weigh divided by density ratio signal for providing a signal corresponding to mach number to attain maximum range;

summing means for adding the mach bias signal to the mach number signal to correct the mach signal for high speed range trade off; and

means responsive to the present gross weight signal for providing a signal corresponding to optimum altitude for maximum range.

35. A system as described in claim 34, in which the fuel management subsystem additionally comprises:

means responsive to the actual altitude signal and the gross weight divided by density ratio signal for providing a signal corresponding to specific range;

means responsive to the specific range signal, the specific range loss signals, the engage commands and the true airspeed signal for providing a signal corresponding to rated fuel consumption; and

means for comparing the rated fuel consumption signal with the fuel flow signal and providing a warning if the fuel flow is improper.

36. A system as described in claim 34, additionally comprising:

means for connecting the computing means for the first segment to the dry aircraft weight signal means for the engaged segment, whereby the present gross weight signal from the first segment computing means remains current as subsequent segments are engage and the optimum altitude signal is valid throughout the mission.

37. A system as described in claim 34, in which the computing means for each segment comprises:

a first ADD circuit for receiving and summing the total fuel weight and the dry fuel weight signals and providing a signal corresponding to present gross weight;

a second ADD circuit for receiving and summing the dry fuel weight signal and a destination reserve fuel weight signal and providing a signal corresponding to destination gross weight;

a first and second memory devices receive the high speed range trade off signal and the calibrated excitation voltage and provide signals corresponding to specific range loss and mach bias;

first and second attenuation means responsive to the high speed angle trade off signal and an altitude signal for attenuating the calibrated excitation voltage in accordance with the effects of altitude and high speed range trade off on airspeed and specific range respectively and having outputs providing first and second attenuated excitations;

third memory device responsive to the first attenuated excitation and the present gross weight signal for providing a signal corresponding to time at the present gross weight;

fourth memory device responsive to the first attenuated excitation and the destination gross weight signal for providing a signal corresponding to time at the destination gross weight;

means responsive to the signals from the third and fourth memory devices and the ambient temperature signal for providing a signal corresponding to segment time;

fifth memory device responsive to the second attenuated excitation and the present gross weight signal for providing a signal corresponding to air range at the present gross weight;

sixth memory device responsive to the second attenuated excitation and the destination gross weight signal for providing a signal corresponding to air range at the destination gross weight;

means responsive to the signals from the fifth and sixth memory devices and the air range signal from the navigational subsystem for providing a signal corresponding to reserve fuel weight;

means responsive to the altitude signal and the present gross weigh signal for providing a signal corresponding to gross weight divided by density ratio; and

means responsive to the altitude signal and the gross weight divided by density ratio signal for providing a signal corresponding to planned airspeed.