Two axes controller

• US 4,150,803 A
• Filed: 10/05/1977
• Issued: 04/24/1979
• Est. Priority Date: 10/05/1977
• Status: Expired due to Term

• Current Assignee: Carlos P. Fernandez
• Original Assignee: Carlos P. Fernandez
• Inventors: Fernandez, Carlos P.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Eisenzopf, Reinhard J.
• Application Number:
  US05/839,647
• Time in Patent Office: 566 Days
• Field of Search: 244/135 A, 244/223, 244/227, 244/228, 244/236, 214/762, 214/13, 214/14, 212/39 A, 212/39 MS, 74/471 XY, 74/475, 74/491, 137/351, 137/615
• US Class Current: 244/135.00A
• CPC Class Codes: B64C 13/0421 control sticks for primary flight controls
• CPC Class Codes: B64D 39/00 Refuelling during flight filling or emptying fuel tanks B64D37/14
• CPC Class Codes: Y10T 74/20201 Control moves in two planes
• CPC Class Codes: Y10T 74/20396 Hand operated

Abstract

A two axis controller for controlling a tanker aircraft in-flight refueling boom while maneuvering prior to engagement with the receiver aircraft and including a boom load alleviation system after engagement. Movement of the control stick is transmitted mechanically to a position transducer. The transducer provides a signal to an actuator to effect boom control. The transducer output is also transmitted to a servo motor which is mechanically connected to the control stick. During the free flight mode, when the operator is manually controlling the boom, the servo motor provides a resisting force to stick movement that varies as a function of the transducer signal. Following coupling of the two airplanes, which initiates the automatic load alleviation system, the same servo motor back drives the control stick in response to boom force and position signals to alleviate boom forces. Manual override of the automatic system is possible at any time.

Claims

1. An apparatus for controlling a mechanical element in angular or translational position, comprising:

a control stick;

position transducer means driven by said control stick for generating a command signal that is a function of said control stick position;

actuator means responsive to said command signal for driving said mechanical element;

servo motor means for receiving said command signal and applying an inverse force to said control stick proportional to said command signal;

force transducer means for measuring force on said mechanical element and generating a force signal that varies as a function of said force, and;

switching means for selectively adding said force signal to said command signal applied to said servo motor;

whereby the force on said control stick varies inversely as a function of said stick position alone or stick position in conjunction with the force on said mechanical element depending on said switching means position.

2. The apparatus as defined in claim 1, further comprising a second position transducer driven by said mechanical element for generating an actual position signal that is a function of actual position of said mechanical element and selectively applied through said switching means, in algebraic combination with said force signal and said command signal to said servo motor means, whereby the force on said control stick is further biased by said actual position of said mechanical element.

3. An apparatus for controlling a mechanical element in angular or translational position, comprising:

a control stick;

first position transducer means driven by said control stick for generating a command signal that is a function of said control stick position;

actuator means responsive to said command signal for driving said mechanical element;

second position transducer means driven by said mechanical element for determining the actual position of the mechanical element and generating an actual position signal;

force transducer means for measuring force on said mechanical element and generating a force signal that varies as a function of said force;

first summing means for summing said actual position signal and said force signal;

switching means connnected to said first summing means output to enable or disable said output;

second summing means connected to said switching means for subtracting said command signal from said switching means output, resulting thereby in a control signal, and

servo motor means responsive to said control signal to apply a force to said control stick that is a function of said control signal,

whereby the force on said control stick is always a function of said command signal and may be biased by said actual position signal and said force signal by closing said switching means.

4. The apparatus as defined in claim 3, wherein said second position tranducer output is also coupled to said actuator, and said actuator compares said first position transducer output to said second position transducer output, determines the polarity and amount of error, and drives said mechanical element in a direction to reduce said error.

5. A two axes controller for imparting command signals to a mechanical element for angular or translational position control comprising:

armrest means adapted to support the forearm of the operator;

a handgrip located forward and above said armrest adapted to be grasped by the hand of the operator while supporting the forearm on said armrest;

first moveable member pivotally mounted to said armrest means for angular motion in a plane about an axis of rotation located below and parallel to the longitudinal axis of said armrest and corresponding to the lateral axis of the mechanical element being controlled;

second moveable member pivotally mounted at one end to said first moveable member and supporting said handgrip at the other end for angular motion in a plane perpendicular to the plane of motion of said first moveable member and allowing said handgrip to move about an axis approximately coinciding with the wrist of the operator and corresponding to the vertical axis of motion of the mechanical element being controlled;

signal generating position transducer means connected to each of said moveable members and driven by said handgrip for generating a command signal that is a function of said handgrip position; and

servo motor means connected to each of said moveable members and responsive to each of said signal generating position transducers output signal to apply a force to said handgrip as an inverse function of said command signals,

whereby the operator will experience a force resisting the movement of said handgrip from neutral position which is a function of said handgrip displacement.

6. A two axes controller for controlling a tanker aircraft in-flight refueling boom, having aerodynamically responsive surfaces for maneuvering said boom before and after engagement with a receivng aircraft comprising:

armrest means adapted to support the forearm of the operator;

a handgrip located forward and above said armrest adapted to be grasped by the hand of the operator while supporting the forearm on said armrest;

first moveable means pivotally mounted to said armrest means for angular motion in a plane about an axis of rotation located below and parallel to the longitudinal axis of said armrest and corresponding to the lateral axis of the boom;

second moveable means pivotally mounted at one end to said first moveable means and supporting said handgrip at the other end for angular motion in a plane perpendicular to the plane of motion of said first moveable means and allowing said handgrip to move about an axis approximately coinciding with the wrist of the operator and corresponding to the vertical axis of motion of the boom being controlled;

signal generating position transducer means connected to each of said moveable means and driven by said handgrip for generating a first and a second command signal, corresponding to each axis of control, proportional to said handgrip position, and wherein each axis further comprises;

actuator means responsive to said command signal for controlling said boom control surface;

servo motor means connected to each of said moveable means for receiving said corresponding command signal and applying an inverse force to said handgrip that is a function of said command signal;

force transducer means attached to said refueling boom for measuring forces on said boom and generating a force signal that is a function of said force, and;

switching means for selectively adding said force signal to said command signal applied to said servo motor;

whereby the force on said handgrip will be an inverse function of said handgrip position alone or said force will be biased by the forces acting on said boom depending on said switching means position.

7. The apparatus as defined in claim 6, further comprising a boom position transducer means connected to each axis of motion of said boom for generating an actual position signal proportional to actual boom position, selectively applied through said switching means in algebraic combination with said force signal and said command signal to said corresponding axis servo motor means, whereby the forces on said handgrip are further biased by said actual position of said boom.

8. The apparatus as defined in claim 7, wherein said switching means for adding said combined force signal and said actual boom position with said command signal for application to said servo means is automatically closed when said boom is engaged with said receiving aircraft.

9. A two axes controller for controlling a tanker aircraft in-flight refueling boom, having aerodynamically responsive surfaces for maneuvering said boom before and after engagement with a receiving aircraft comprising:

armrest means adapted to support the forearm of the operator;

a handgrip located forward and above said armrest adapted to be grasped by the hand of the operator while supporting the forearm on said armrest;

first moveable means pivotally mounted to said armrest means for angular motion on a plane about an axis of rotation located below and parallel to the longitudinal axis of said armrest and corresponding to the lateral axis of the boom;

second moveable means pivotally mounted at one end to said first moveable means and supporting said handgrip at the other end for angular motion in a plane perpendicular to the plane of motion of said first moveable means and allowing said handgrip to move about an axis approximately coinciding with the wrist of the operator and corresponding to the vertical axis of motion of the boom being controlled;

first position transducer means connected to each of said moveable means and driven by said handgrip for generating a first and a first prime command signal, corresponding to each axis of control, proportional to said handgrip position, and wherein each axis further comprises;

(1) actuator means responsive to said command signal for driving said boom;

(2) second position transducer means driven by said boom for determining the actual position of the boom and generating an actual boom position signal;

(3) force transducer means for measuring force on said boom and generating a boom force signal proportional to said force;

(4) first summing means for summing said actual boom position signal and said boom force signal;

(5) switching means connected to said first summing means output to enable or disable said output;

(6) second summing means connected to said switching means for subtracting said command signal from said switching means output, resulting thereby in a control signal, and

(7) servo motor means connected to said corresponding moveable means and responsive to said control signal to apply a force to said handgrip proportional to said control signal,

whereby the force on said handgrip is always a function of said handgrip position and may be biased by the forces acting upon said boom by closing said switching means.

10. The apparatus as defined in claim 9, wherein said actual boom position signal is also coupled to said actuator, and said actuator compares said first position transducer output to said actual boom position signal, determines the polarity and amount of error, and drives said boom in a direction to reduce said error.

11. The apparatus as defined in claim 11, wherein said first moveable means is a shaft journaled for rotation, and wherein

said second moveable means is a linkage, further comprising:

(1) a first link rigidly fixed to said shaft in a vertical plane when said shaft is in a neutral control position;

(2) a second link pivotally connected to the lower end of said first link;

(3) a first rocker arm pivotally connected at one distal end to said second link;

(4) a second rocker arm pivotally connected at the upper end of said first link and pivotally connected at its intermediate point to the intermediate point of said first rocker arm to form a first four bar linkage having two protruding arms;

(5) a third link pivotally attached to the distal end of the protruding arm of said second rocker arm; and

(6) a fourth link pivotally attached to the protruding arm of said first rocker arm at one end and pivotally attached to said third link at the other end and supporting said handgrip on its upper surface to form a second four bar linkage having a common pivot with said first four bar linkage,

whereby a linkage is formed for translating motion to said handgrip in an arc described about a point approximately coincidental with the wrist of the operator for boom pitch axis control and rotation of said linkage, by a roll motion of the forearm of the operator, about said shaft for roll control.

12. The apparatus as defined in claim 11, further comprising:

a spring biasing means connected between said shaft and said second link for counterbalancing the weight of said linkage and handgrip.