Active landing gear damper

Patent metadata

Field	Value
Publication number	US-9708057-B2
Application number	US-201414188589-A
Country	US
Kind code	B2
Filing date	Feb 24, 2014
Priority date	Feb 24, 2014
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

An active landing gear damping system and method for decelerating a vehicle during a terrain impact event, such as an aircraft landing or crash. The system monitors aircraft state data and terrain information to predict an impact of the vehicle with the terrain. The system can then determine a target damper force for each landing gear of the vehicle and a predicted damper velocity at the time of impact. Each landing gear can include an adjustable damper valve, wherein adjustment of the damper valves varies the damping coefficient of the respective dampers. The system can adjust valves of the respective dampers to provide the target force based on the predicted damper velocity. After an impact begins, the system can continuously monitor and adjust the valve to maintain the target force.

First claim

What is claimed is:

1. A damper for a vehicle suspension system, the damper comprising:
a cylinder defining a damper volume therein, wherein the cylinder is configured for connection to a first suspension component of the vehicle suspension system;
a piston disposed in the cylinder, wherein the piston includes a shaft extending out of a first end of the cylinder, wherein the shaft is configured for connection to a second suspension component of the vehicle suspension system that is movable relative to the first suspension component, wherein the shaft includes a hollow region, and wherein the piston is movable within the cylinder;
a housing arranged at a second opposing end of the cylinder, wherein a portion of the housing extends past a wall of the cylinder, wherein the housing defines a fluid channel with an inlet in fluid communication with the damper volume on a first side of the piston and an outlet in fluid communication with the damper volume on a second side of the piston, and wherein the outlet extends through an aperture in the piston and into the hollow region;
an adjustable damper valve disposed in the fluid channel between the inlet and the outlet in the portion of the housing, wherein the damper valve defines a valve channel, wherein the valve channel is rotatable relative to the fluid channel to provide varying degrees of alignment between the fluid channel and the valve channel such that rotation of the damper valve changes a damping coefficient of the damper;
a motor, wherein operation of the motor adjusts the damper valve; and
a controller configured to:
receive a target damper force and initial damper velocity in response to a predicted vehicle impact;
in response to receiving the target damper force and initial damper velocity, operate the motor to adjust the damper valve to a position corresponding to a damping coefficient that results in the target damper force at the initial damper velocity; and
thereafter, operate the motor during vehicle impact to reduce any difference between an actual damping force of the damper and the target damping force.

2. The damper of claim 1 , further comprising an impact prediction module configured to output the target damper force and initial damper velocity to the controller.

3. The damper of claim 2 , wherein the impact prediction module receives at least one of vehicle state data and terrain information, wherein, in response to at least one of the received vehicle state data and terrain information, the impact prediction module predicts impact parameters that include at least one of:
a terrain surface type,
an aircraft impact velocity,
an impact attitude relative to the terrain at time of impact,
an aircraft gross weight at time of impact, and
an aircraft center of gravity at time of impact;

wherein the impact prediction module calculates the target damper force based on a target landing gear load factor and the predicted impact parameters, and wherein the impact prediction module calculates the initial damper velocity based on the predicted impact parameters.

4. The damper of claim 3 , wherein the vehicle is an aircraft, and wherein the vehicle state data comprises at least one of:
pitch, pitch rate, and pitch acceleration data;
roll, roll rate, and roll acceleration data;
yaw, yaw rate, and yaw acceleration data;
a three-dimensional velocity vector;
a three-dimensional acceleration vector;
a position;
an altitude above ground level;
an aircraft weight; and
an aircraft center of gravity.

5. The damper of claim 3 , wherein the terrain information comprises at least one of:
terrain elevation;
terrain slope; and
terrain surface type.

6. The damper of claim 3 , wherein the impact parameters further comprise lift generated by the aircraft at the time of impact, and wherein the target damper force is reduced by the lift generated by the aircraft at the time of impact.

7. The damper of claim 1 , wherein the motor comprises a continuously adjustable servomotor.

8. The damper of claim 1 , further comprising a gearbox arranged between the motor and the adjustable valve, wherein the gearbox is configured to multiply torque from the motor and apply the multiplied torque to the adjustable valve.

9. The damper of claim 1 , further comprising a gearbox arranged between the motor and the adjustable valve, wherein the gearbox is mounted to the portion of the housing extending past the wall of the cylinder, and wherein the gearbox is configured to multiply torque from the motor and apply the multiplied torque to the adjustable valve.

10. The damper of claim 1 , wherein the shaft includes a hollow region, and wherein the outlet extends through an aperture in the piston.

11. A damper for an aircraft suspension system, the damper comprising:
a cylinder defining a damper volume therein, wherein the cylinder is configured for connection to a first suspension component of the vehicle suspension system;
a piston disposed in the cylinder, wherein the piston includes a shaft extending out of a first end of the cylinder, wherein the shaft is configured for connection to a second suspension component of the vehicle suspension system that is movable relative to the first suspension component, wherein the shaft includes a hollow region, and wherein the piston is movable within the cylinder;
a housing arranged at a second opposing end of the cylinder, wherein a portion of the housing extends past a wall of the cylinder, wherein the housing defines a fluid channel with an inlet in fluid communication with the damper volume on a first side of the piston and an outlet in fluid communication with the damper volume on a second side of the piston, and wherein the outlet extends through an aperture in the piston and into the hollow region;
an adjustable damper valve disposed in the fluid channel between the inlet and the outlet in the portion of the housing, wherein the damper valve defines a valve channel, wherein the valve channel is rotatable relative to the fluid channel to provide varying degrees of alignment between the fluid channel and the valve channel such that rotation of the damper valve changes a damping coefficient of the damper;
a motor, wherein operation of the motor adjusts the damper valve;
an impact prediction module configured to output a target damper force and initial damper velocity, wherein the impact prediction module predicts an amount of lift generated by the aircraft at the time of a predicted vehicle impact, and wherein the target damper force is reduced by an amount proportional to the lift generated by the aircraft; and
a controller configured to:
receive the target damper force and initial damper velocity in response to a predicted vehicle impact;
in response to receiving the target damper force and initial damper velocity, operate the motor to adjust the damper valve to a position corresponding to a damping coefficient that results in the target damper force at the initial damper velocity; and
thereafter, operate the motor during aircraft impact to reduce any difference between an actual damping force of the damper and the target damping force.

12. The damper of claim 11 , wherein the impact prediction module receives at least one of vehicle state data and terrain information, wherein, in response to at least one of the received vehicle state data and terrain information, the impact prediction module predicts impact parameters that include at least one of:
a terrain surface type,
an aircraft impact velocity,
an impact attitude relative to the terrain at time of impact,
an aircraft gross weight at time of impact, and
an aircraft center of gravity at time of impact;

Assignees

• Birchette Terrence S
• Bolukbasi Akif O
• Boeing Co

Inventors

• Birchette Terrence S
• Bolukbasi Akif O

Classifications

• B64D45/00

  Aircraft indicators or protectors not otherwise provided for · CPC title

• B64C25/58 Primary

  Arrangements or adaptations of shock-absorbers or springs (shimmy-dampers B64C25/50) · CPC title

• B64C25/60 Primary

  Oleo legs · CPC title