Apparatus for stabilization of an instrumentation platform

Patent metadata

Field	Value
Publication number	US-12535121-B2
Application number	US-202318370709-A
Country	US
Kind code	B2
Filing date	Sep 20, 2023
Priority date	Sep 20, 2022
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

An apparatus for rotation rate damping of a suspended platform, the apparatus including a plurality of vertically-extended partially-filled fluid reservoirs, each of the reservoirs being open at a top and offset from a center of gravity of the suspended platform, the reservoirs being connected by tubing permitting fluid to flow between reservoirs in response to gravitational accelerations; wherein motion of the fluid in the tubing creates damping of the rotational motion of the platform.

First claim

The invention claimed is:

1 . An apparatus for rotation rate damping of a suspended platform, the apparatus comprising:
a plurality of vertically-extended partially-filled fluid reservoirs, each of the reservoirs being open at a top and offset from a center of gravity of the suspended platform, the reservoirs being connected by tubing permitting fluid to flow between reservoirs in response to gravitational accelerations; wherein motion of the fluid in the tubing creates damping of the rotational motion of the platform; wherein the plurality of reservoirs consists of pairs of reservoirs, each diametrically offset horizontally from the center of gravity at a position diametrically opposed to an other reservoir in the pair; and where the reservoirs in a pair are connected to each other by tubing, but not to reservoirs of any other pair.

2 . The apparatus of claim 1 where two pairs of reservoirs are arranged with offsets from the center of gravity which are at right angles to each other.

3 . The apparatus of claim 1 , wherein the tubing extends in two half rings about opposite sides of the platform between the pair of reservoirs.

4 . The apparatus of claim 3 , wherein the tubing is connected to each reservoir of the pair of reservoirs using a T-junction.

5 . The apparatus of claim 4 , wherein the T-junctions and the tubing have uniform dimensions.

6 . The apparatus of claim 1 , wherein each reservoir contains hollow shafts therein to prevent sloshing of the fluid.

7 . The apparatus of claim 6 , wherein each reservoir contains at least two bundles of hollow shafts, the apparatus further comprising a separator between the bundles of hollow shafts allowing fluid to flow from hollow shaft to hollow shaft.

8 . The apparatus of claim 6 , wherein a separator is configured to block a subset of hollow shafts, thereby allowing tuning of the motion damping.

9 . The apparatus of claim 6 , further comprising a fluid permeable layer under a bundle of hollow shafts to allow fluid to flow into the tubes.

10 . The apparatus of claim 1 , wherein the tubing connects all pairs of reservoirs with a single tube.

11 . The apparatus of claim 1 , wherein the platform contains instrumentation for Audio Frequency Magnetic (AFMAG) exploration.

12 . The apparatus of claim 1 , wherein the platform contains instrumentation for Controlled-Source Airborne ElectroMagnetic (AEM) exploration.

13 . The apparatus of claim 1 , wherein each reservoir includes a port at an upper surface thereof for air ingress into the reservoir or egress from the reservoir.

14 . The apparatus of claim 13 , wherein each reservoir contains a baffle apparatus, the baffle apparatus comprising a plurality of hollow shafts therein, wherein the apparatus is tuned by blocking a subset of the hollow shafts.

15 . The apparatus of claim 1 , wherein the platform rests on a single pivot point.

16 . The apparatus of claim 1 , wherein the apparatus is designed to adhere to:

2
⁢
ρ
⁢

AD
2

MH

<
1

where ρ is a density of a working fluid; A is a fluid surface area in each reservoir; D is a horizontal offset of each reservoir from a suspension point; M is a mass of the platform, including the apparatus; and H is a distance between the suspension point and a center of mass.

17 . The apparatus of claim 1 , wherein a density of the fluid, a flow rate of the fluid, a length of the tubing, and a viscosity of the fluid have values such that fluid flow through the tubing has a Reynolds number corresponding to a laminar flow.

18 . The apparatus of claim 1 , further comprising restriction valves to restrict fluid flow such that a natural fluid re-equilibration time constant for the reservoirs, in response to a platform tilt, is less than but a same order of magnitude as a pendular oscillation frequency of the platform.

Assignees

• Vale Sa

Inventors

• Polzer Benjamin David
• Bailey Richard Curtis

Classifications

• F16F2238/04

  Damper · CPC title

• F16F2232/02

  Rotary · CPC title

• F16F2230/08

  Sensor arrangement · CPC title

• F16F15/366

  using fluid or powder means, i.e. non-discrete material · CPC title

• F16F9/512

  Means responsive to load action, {i.e. static load} on the damper or {dynamic} fluid pressure {changes} in the damper, {e.g. due to changes in velocity (F16F9/504, F16F9/516 take precedence; non-automatic damper adjustment from a distance using servo control, the servo pressure being created by the flow of damping fluid F16F9/465; self-pumping fluid springs in vehicle suspensions B60G17/044)} · CPC title