FIELD OF THE INVENTION
This invention relates to flight control systems and spaceflight control systems and the redundancy and sensor feedback given to the pilot or astronaut by stick motion, position and force felt in the finger tips and hand of the pilot or astronaut when an automated system is controlling the craft or another crew-member manipulates the controls or an independent system tries to shake the stick or move the stick to warn the pilot.
BACKGROUND OF THE INVENTION
Many so called “fly-by-wire” transport category prior-art dual control aircraft have controls that do not move in unison and do not transmit by feel the manipulation of the controls by one pilot to the other pilot or control surface aerodynamic deflection force or the auto-pilot or automation moving the controls or control surfaces, or warning systems that transmit warnings through feel in the stick or control column. In the case of two pilots with their hands on the controls at the same time the pilot applying the greater force does not override the other pilot. Button presses or procedural steps including call outs are necessary to transfer control or to override the other stick defeating an important redundancy that previously existed on even the earliest aircraft. Additionally when an auto-thrust system is changing settings many transport category aircraft have thrust levers that are not moved by automation so the additional instant redundant feedback for engine control settings by feel has been lost and only can be seen by latent instrument movement of thrust settings in the pilots visual frame of reference.
A large number of prior art transport category aircraft flying today force the pilot to use his sense of vision much more to make up for loss of touch feedback. Whoever is at the controls can only convey what is being done with the stick to the other pilot visually and/or aurally and not by feel in the other pilots controls (other pilots fingers and hands). Methods of warning the pilot of imminent danger through feel exist on many aircraft flying today except for a large number of so called “fly by wire” transport category aircraft. The prior art stick shaker and stick pusher methods of warning the pilot through feel of a problem have been discarded. Therefore the aircraft can be said to be less automated in this respect causing added work for the pilots especially in emergency situations and especially to find out what automation may be doing. In many emergent situations such as cockpit display failure, smoke in the cockpit, or unreliable sensor/instrument indications the pilot who would normally not have to speak about control position must talk to the other pilot creating extra chatter. In the case of automated flight neither control stick moves at all nor do the thrust levers on many transport category aircraft flying today.
Resultant instrument readings that must be used in place of the sense of touch is not trivial in providing instant sensory information used by the pilot to have awareness of the status of the aircraft and control positions. Earliest aircraft had cables to transmit control movement by one pilot to the other pilot via movements in both sticks or control columns and aerodynamic forces were also transmitted to the sticks or yoke and control column giving instant awareness of the status of the aircraft and control positions. Additionally the thrust levers, rudder pedals and in the case of turbo-props power levers, and propeller levers used cables or other mechanical mechanisms to indicate commanded values by their position. Feedback to the pilot what commanded values were set could easily be felt by the position of the levers. Auto-thrust systems moved the thrust-levers and in the case of the autopilot the yoke and control columns were moved indicating by feel what the current commanded position or setting was.
More widespread use of compact multiprocessor devices and their increased availability has made the application of multiprocessing to many applications much less expensive and compact and facilitates real time parallel computation of vector dot products to apply motion and torque to computer controlled electromagnets to directly drive the motion and maintain the position of a shaft on the end of a gimbal.
In view of these disadvantages and advantages this invention addresses this lack of redundancy in many modern transport category aircraft in flight today and to carry forward the redundant safety feature built into some of the earliest aircraft flown with the earliest art cable linked control systems which allowed feedback to the pilot through feel to indicate control movements by the other pilot, aerodynamic forces or the computer/automated flight control system actions via a robust and cost effecting parallel computing electronic means.
SUMMARY OF THE INVENTION
A stick with a universal joint mounted on its base to maintain a planar sheet parallel to the floor but able to move freely translating the motion input at the top of the stick. Up the shaft a gimbal is mounted at a fixed location which allows the motion to translate to the lower guide plate housed below and clear of the pilot's hand.
The stick assembly described above is combined with a parallel real time computer controlled system that moves the stick to a precise position electronically with a specific torque, speed, acceleration or deceleration and position path with the use of electromagnetic chain links of a chain forming a Traction Catenary and magnetic or electromagnetic beads strung on a wire or tether which also provide traction. As the auto-pilot flies the aircraft or a pilot flies the aircraft the other pilot is given feel that indicates what the autopilot or other pilot is doing rather than only seeing it collaterally by instrument changes. Aerodynamic control force is also added to the stick feel. Augmented feel is also provided by Feel Fingers which can communicate to the pilot heading information and a bracelet which fits around the shaft of the stick which tilts to warn the pilot.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects and advantages of the invention will become more clear with reference of the following detailed description as illustrated by the drawings in which:
FIG. 1 is a schematic diagram of a parallel stick control computing system showing the combined stick controller and other elements according to this invention
FIG. 2 is a flow diagram of a procedure for each stick control processor
FIG. 3 is a cutaway of an elementary electrical and mechanical parts according to this invention
FIG. 4 is a view of an X and Y coordinated motion drive of an embodiment of this invention which uses chains of electromagnets called Traction Catenaries and an advantaged pulley system
FIG. 5 is an embodiment of the invention which uses three spokes of Traction Catenaries to directly drive shaft movement
DETAILED DESCRIPTION
FIGS. 1 through 5 detail a simple parallel computing environment with accompanying mechanical assembly and parallel computerized electronic control according to this invention. Nevertheless, this description should be considered to apply to any type of lever or stick or control column and yoke. Other generalized adaptations include electronic gimbal applications wherein precise positioning with strong position holding and redundant position encoding and control over torque and acceleration and velocity of shaft or other movement is required.
FIG. 1 details a schematic diagram of a parallel computing method embodied by this invention to control all stick parameters and movement within 1 ms or less with a goal of less than 700 ns wherein each stick has essentially a black box 2, 4, and 7 or however many are in the system 6. Each black box has its own processing units and takes as input: sensor information 11 from the control surfaces 18, the automated flight control system or auto-pilot 10 via bus 9, other stick output 3, 5 and 8 via a bus or other broadcast method 1 which includes: torque, acceleration, deceleration, velocity, friction or holding force, the stick shaker, and the stick pusher. All flight parameters: pitot static airspeed, computed GPS based ground speed, barometric altitude, GPS altitude, vertical speed, magnetic heading, GPS ground track, temperature, altitude 12 are fed to each black box by discrete channels 19, ball left, ball right . . . . All of these signals are independently redundant with at least three other independent sensors and three independent and unique signal paths 17 and wherever possible independently written algorithms and sense methods are used in each redundant system. A voting method is used to flag and throw out any possibly failing sensor or sensor signal path. An Augmented Feel Feedback Bracelet is used to warn the pilot through feel of a near stall condition and is used to warn the pilot through feel by pushing the pilot's hand forward when an imminent stall is sensed. Augmented Feel feedback Fingers 14 have independent sensor input 13 and the Augmented Feel Feedback Bracelet 16 has independent input 15 as well. The Augmented Feel Feedback Fingers and Augmented Feel Feedback Bracelet are independent systems which feed directly 20 and 21 into the stick black boxes 2, 4, and 7 or however many are in the system 6.
FIG. 2 details a flow diagram of a parallel processed procedure for each stick control processor. Each black box acquires all of the parameters (described by their respective command out vector) 22 and performs a dot product 23 of the individual stick command direction and force to produce a command for its own stick 24 which it rapidly executes. A new command out vector for the individual stick is prepared 25. This point in time is a synchronization point wherein all stick black boxes 26 wait at a barrier until all others have reached a point wherein all individual stick black boxes are ready to issue a stick command. This is the synchronization barrier 27. This command produces the appropriate acceleration, velocity and torque and position path with corresponding induction of the electromagnets in each link of a system which produces traction by contracting or expanding or by the traction produced by magnetic beads or electromagnetic beads which are drawn laterally toward a magnetized material or electromagnet. Once all of the sticks have reached this barrier all black boxes are said to be in synchronization and broadcast their respective command out vectors 28. All of this happens in less than 1 ms. A provision is made wherein all sticks can revert to a constant friction force and an open loop dead joystick (which is much like what is used in normal operation of current “fly by wire” transport category aircraft today) configuration wherein stick torque and positioning electromagnetics are turned off and simple position encoding is used.
FIG. 3 details an embodiment of this invention with 37 Augmented Feel Feedback Fingers which communicate to the pilot via protruding out of openings in the shaft to indicate various information to the pilot as well as a Augmented Feedback Feel Bracelet 38 which tilts the lower part of the hand to indicate to the pilot of an impending dangerous situation. The bracelet is tilted up by the computer which tilts the pilots hand up encouraging him to pull back on the stick. The main stick 29 is secured to the top of an enclosure with a spherical bearing 33 which allows a second shaft 31 to freely move up and down inside the enclosure where a universal joint 32 is secured to a plate 39 which limits motion to one plane via bearings 34. Motion is imparted upon the shaft via X 36 and Y rack and pinions with linear slides 35 to allow X motion along the Y axis and Y motion along the X axis.
FIG. 4 details an embodiment of this invention with 40 Traction Catenary Pulley systems to drive X and Y coordinated motion where a fixed multiple grooved pulley 48 is connected to another pulley in simple loops to a second freely movable multiple grooved pulley 47. The Traction Catenary pulley systems squeeze together when current is induced via inducers 41 creating traction which in turn is advantaged by a 4:1 double block which in turn via a simple pulley 49 has a strain gauge 50 for each axis X and Y connected to a simple pulley 49 for pivot and a slide enclosed 43 control rod 44 which is connected directly to the load which is the second shaft of a concentric sliding conjugate shaft 31.
FIG. 5 details an embodiment of this invention wherein a universal joint 32 secures a single shaft 45 with Augmented Feel Feedback Fingers 37 and an Augmented Feel Feedback Bracelet 38 which is directly driven by 3 evenly place Traction Catenary 40 drive pulley systems with fixed pulleys 48 secured to the same plate as the universal joint each spaced at 120 degree radials wherein traction on the shaft is connected via the other non-fixed pulley 47 wherein inducers 41 (only one shown to avoid drawing clutter) are spaced at 120 radials below each Traction Catenary.