INTEGRATED LOAD SENSING SYSTEM

• US 20100264263A1
• Filed: 04/19/2009
• Published: 10/21/2010
• Est. Priority Date: 04/19/2009
• Status: Active Grant

• Current Assignee: Safran Electronics & Defense Avionics USA LLC (Safran SA)
• Original Assignee: Rockwell Collins, Inc. (Rtx Corporation)
• Inventors: SHAHEEN, MILAD A., Wright, Andrew M.
• Granted Patent: US 8,191,824 B2
• Time in Patent Office: Days
• US Class Current: 244/99.300
• CPC Class Codes: B64C 13/24 Transmitting means
• CPC Class Codes: G01L 1/2225 the direction being perpendicular to the central axis
• CPC Class Codes: G01L 5/22 for measuring the force applied to control members, e.g. control members of vehicles, triggers

Abstract

An integrated load sensing system includes a housing including a coupling pin portion thereof. A bridge circuit includes a set of strain gauges bonded to the coupling pin portion. A bridge circuit excitation, error correction, and amplification (BCEECA) subsystem is operatively connected to the bridge circuit for receiving indications of shear load from the strain gauges, correcting signal error, and amplifying the indications of shear load. The BCEECA subsystem provides amplified output signals. A power conditioning module is operatively connected to the BCEECA subsystem for receiving power from an external power supply and conditioning power to an appropriate state for driving the bridge circuit as well as an appropriate state for error correction and amplification circuitry within the BCEECA subsystem. A logic module compares the amplified output signals to a predetermined signal threshold and provides latching of enunciation in accordance with a selected delay after the threshold is surpassed. An enunciation element providing enunciation of the output signals surpassing the signal threshold in accordance with the logic module. The bridge circuit, the BCEECA subsystem, the power conditioning module, the logic module, and the enunciation element are contained and sealed within the housing. The invention includes a method for in situ testing of a shear load sensing system for a mechanical system.

Claims

1. An integrated load sensing system, comprising:

a) a housing including a coupling pin portion thereof;

b) a bridge circuit comprising a set of strain gauges bonded to said coupling pin portion;

c) a bridge circuit excitation, error correction, and amplification (BCEECA) subsystem operatively connected to said bridge circuit for receiving indications of shear load from said strain gauges, correcting signal error, and amplifying said indications of shear load, wherein said BCEECA subsystem provides amplified output signals;

d) a power conditioning module operatively connected to said BCEECA subsystem for receiving power from an external power supply and conditioning power to an appropriate state for driving the bridge circuit as well as an appropriate state for error correction and amplification circuitry within said BCEECA subsystem;

e) a logic module for comparing said amplified output signals to a predetermined signal threshold, and providing latching of enunciation in accordance with a selected delay after said threshold is surpassed; and

,

f) an enunciation element providing enunciation of said output signals surpassing said signal threshold in accordance with said logic module,

wherein, said bridge circuit, said BCEECA subsystem, said power conditioning module, said logic module, and said enunciation element are contained and sealed within said housing.

2. The integrated load sensing system of claim 1, wherein said set of strain gauges have the capability of also measuring torsion load in addition to said shear load, said amplified output signals being induced by a known applied torsion.

3. The integrated load sensing system of claim 2, wherein said logic module comprises:

a) means for setting said known applied torsion to a level at which an expected signal based upon said known applied torsion surpasses said predetermined signal threshold;

b) means for comparing said amplified output signals induced by said known applied torsion to said predetermined signal threshold; and

,

c) means for providing binary enunciation if said predetermined shear load signal threshold is surpassed.

wherein proper functionality of said integrated load sensing system is indicated by said binary enunciation.

4. The integrated load sensing system of claim 2, wherein said logic module comprises:

a) means for directly accessing said amplified output signals induced by said known applied torsion; and

b) means for comparing said amplified output signals induced by said known applied torsion to an expected signal based upon said known applied torsion;

wherein proper functionality of said integrated load sensing system is determined by the level of deviation of said comparison.

5. A method for in situ testing of a shear load sensing system for a mechanical system, comprising the steps of:

a) providing a load sensing system having a capability of sensing torsion loads not normally produced during operation with the same sensor elements used to sense shear loads produced during normal operation;

b) installing said load sensing system in said mechanical system;

c) activating said load sensing system by applying a known torsion thereto, thereby producing a torsion induced signal;

d) verifying the proper functionality of said shear load sensing system by determining if said torsion induced signal matches an expected signal based upon said known torsion.

6. The method of claim 5, wherein said step of verifying the proper functionality comprises the steps of:

a) applying said known torsion to a level at which said expected signal surpasses a predetermined signal threshold;

b) comparing said torsion induced signal to said predetermined signal threshold; and

,

c) providing binary enunciation if said predetermined signal threshold is surpassed.

7. The method of claim 5, wherein said step of verifying the proper functionality comprises the steps of:

a) directly accessing said torsion induced signal; and

,

b) comparing said torsion induced signal to said expected signal based upon said known torsion,

wherein said proper functionality is determined by the level of deviation of said comparison.

8. A system for in situ testing of a shear load sensing system for a mechanical system, comprising:

a) means for activating a load sensing system installed in a mechanical system, said load sensing system being of a type having a capability of sensing torsion loads not normally produced during operation with the same sensor elements used to sense shear loads produced during normal operation, said activation being implemented by applying a known torsion thereto, thereby producing a torsion induced signal; and

,

b) means for verifying the proper functionality of said shear load sensing system by determining if said torsion induced signal matches an expected signal based upon said known torsion.

9. An actuator system for an aircraft of a type having a primary aircraft structure, a secondary aircraft structure and a control surface positionable relative to said primary and secondary aircraft structures, the load path between the primary and secondary aircraft structure and the control surface defining a dual load path, said actuator system, comprising:

a) a shear load sensing system securely attached to a secondary aircraft structure; and

,

b) a system for in situ testing of said shear load sensing system, comprising;

i. means for activating said shear load sensing system, said shear load sensing system being of a type having a capability of sensing torsion loads not normally produced during operation with the same sensor elements used to sense shear loads produced during normal operation, said activation being implemented by applying a known torsion thereto, thereby producing a torsion induced signal; and

,

ii. means for verifying the proper functionality of said shear load sensing system by determining the level of deviation of said torsion induced signal from an expected signal based upon said applied known torsion.

10. An actuator system for an aircraft of a type having a primary aircraft structure, a secondary aircraft structure and a control surface positionable relative to said primary and secondary aircraft structures, the load path between the primary and secondary aircraft structure and the control surface defining a dual load path, said actuator system, comprising:

a) an upper actuator assembly, comprising;

i. an upper actuator assembly housing;

ii. a gear assembly supported by said upper actuator assembly housing;

iii. a motor assembly operatively associated with said gear assembly;

iv. an upper primary gimbal assembly mounted to said upper actuator assembly housing, said upper primary gimbal assembly being securely connected to a primary aircraft structure; and

,

v. an upper load sensing assembly securely attached to a secondary aircraft structure;

b) a ball screw assembly operatively connected to said gear assembly, said ball screw assembly, comprising;

i. a ball screw;

ii. a ball nut assembly translatable along said ball screw; and

,

iii. a secondary inverted thread nut in an unloaded standby mode operatively positioned about said ball nut assembly;

c) a tie-rod assembly positioned within said ball screw assembly, said tie-rod assembly having an upper end securely attached to said upper load sensing assembly, wherein said upper load sensing assembly defines an upper portion of a secondary load path of a dual load path between the secondary aircraft structure and a control surface, said dual load path including a primary load path acting and reacting the applied aerodynamic load to the control surface and said secondary load path in a stand-by, unloaded mode, said upper load sensing assembly providing upper indications of the applied forces in said upper portion of said secondary load path when an upper portion of the primary load path is disconnected;

d) a lower actuator assembly, comprising;

i. a lower primary gimbal assembly operatively connected to said ball screw assembly, defining a lower portion of the primary load path;

ii. a lower secondary gimbal assembly positioned about said lower primary gimbal assembly and securely connected to the control surface;

iii. a yoke assembly operatively connected to said secondary inverted thread nut and to said lower secondary gimbal assembly; and

,

iv. a lower load sensing assembly securely attached to said yoke assembly for providing said operative connection between said yoke assembly and said lower secondary gimbal assembly, wherein,

1. a lower portion of said primary load path is defined by the load from said ball screw to said ball nut assembly to said lower primary gimbal assembly to said control surface;

2. a lower portion of said secondary load path is defined by the load from said ball screw to said secondary inverted thread nut to said yoke assembly to said lower load sensing assembly to said lower secondary gimbal assembly to said control surface; and

,

3. said lower load sensing assembly provides lower indications of the applied forces in said lower portion of said secondary load path when the lower portion of said primary load path is disconnected; and

,

wherein at least one of said load sensing assemblies, comprises an integrated load sensing system, comprising;

a) a housing including a coupling pin portion thereof;

b) a bridge circuit comprising a set of strain gauges bonded to said coupling pin portion for receiving one of either i) said upper indications of the applied forces or ii) said lower indications of the applied forces;

c) a bridge circuit excitation, error correction, and amplification (BCEECA) subsystem operatively connected to said bridge circuit for receiving indications of shear load from said strain gauges, correcting signal error, and amplifying said indications of shear load, wherein said BCEECA subsystem provides amplified output signals;

d) a power conditioning module operatively connected to said BCEECA subsystem for receiving power from an external power supply and conditioning power to an appropriate state for driving the bridge circuit as well as an appropriate state for error correction and amplification circuitry within said BCEECA subsystem;

e) a logic module for comparing said amplified output signals to a predetermined signal threshold, and providing latching of enunciation in accordance with a selected delay after said threshold is surpassed; and

,

f) an enunciation element providing enunciation of said output signals surpassing said threshold in accordance with said logic module,

wherein, said bridge circuit, said BCEECA subsystem, said power conditioning module, said logic module, and said enunciation element are contained and sealed within said housing.

11. The actuator system of claim 10, wherein said control surface comprises a horizontal stabilizer.

12. The actuator system of claim 10, wherein said control surface comprises an aileron.

13. The actuator system of claim 10, wherein said control surface comprises a wing trailing edge flap.

14. The actuator system of claim 10, wherein said control surface comprises a wing leading edge slat.

15. The actuator system of claim 10, wherein said control surface comprises an elevator.

16. The actuator system of claim 10, wherein said control surface comprises an Elevon.

17. The actuator system of claim 10, wherein said control surface comprises a Flaperon.

18. The actuator system of claim 10, wherein said control surface comprises a wing.