US-20260125141-A1 - Magnetic Mine Sweeping

US20260125141A1US 20260125141 A1US20260125141 A1US 20260125141A1US-20260125141-A1

Abstract

A magnetic mine countermeasure payload device with a non-magnetic plate, and magnetic elements, each having a north magnetic pole and a south magnetic pole, affixed to the plate in a magnetic array. A rotational shaft is coupled to the plate, with a motor coupled to the shaft, and an electrical power source electrically connected to the motor. The motor is configured to at least one of selectively rotate the magnetic array, thereby creating an AC magnetic moment in the magnetic mine countermeasure payload device, and not rotate the magnetic array, thereby enabling a DC magnetic moment in the magnetic mine countermeasure payload device.

Inventors

Christopher M. Rey
Trever H. Carnes

Assignees

TAI-YANG RESEARCH COMPANY

Dates

Publication Date: 20260507
Application Date: 20251031

Claims (20)

1 . A magnetic mine countermeasure payload device comprising: a non-magnetic plate, magnetic elements, each having a north magnetic pole and a south magnetic pole, the magnetic elements affixed to the plate in a magnetic array, a rotational shaft coupled to the plate, a motor coupled to the shaft, and an electrical power source electrically connected to the motor, wherein the motor is configured to at least one of selectively rotate the magnetic array, thereby creating an AC magnetic moment in the magnetic mine countermeasure payload device, and not rotate the magnetic array, thereby enabling a DC magnetic moment in the magnetic mine countermeasure payload device.
2 . The magnetic mine countermeasure payload device of claim 1 , wherein the magnetic elements include at least one of a permanent magnet, and a superconducting trapped flux magnet.
3 . The magnetic mine countermeasure payload device of claim 1 , wherein the magnetic elements have a shape that includes at least one of round, square, rectangular, hexagonal, and multi-polygonal.
4 . The magnetic mine countermeasure payload device of claim 2 , wherein the permanent magnet is formed of at least one of Nd—Fe—B, Sm—Co, and Al—Ni—Co.
5 . The magnetic mine countermeasure payload device of claim 2 , wherein the superconducting trapped flux magnet is formed of at least one of Bi—Sr—Ca—Cu—O, Re—Ba—Cu—O, Tl—Ba—Ca—Cu—O, Hg—Ca—Ba—Cu—O, Mg—B, Nb—Ti, Nb—Sn, N—N, and Nb—Ge.
6 . The magnetic mine countermeasure payload device of claim 1 , further comprising a gearbox mechanically coupled between the motor and the shaft.
7 . The magnetic mine countermeasure payload device of claim 1 , wherein the device generates at least one of a steady state magnetic moment, and a time varying magnetic moment.
8 . The magnetic mine countermeasure payload device of claim 1 , wherein multiple plates are rotated at at least one of a constant angular velocity, and variable angular velocity.
9 . The magnetic mine countermeasure payload device of claim 1 , wherein the plates are aligned in at least one of a parallel configuration, and an anti-parallel configuration.
10 . The magnetic mine countermeasure payload device of claim 1 , further comprising a hermetic water-tight container configured to house the magnetic mine countermeasure payload.
11 . The magnetic mine countermeasure payload device of claim 1 , wherein the payload is mounted to at least one of an unmanned surface vessel, an unmanned underwater vessel, a manned surface vessel, and a towable array.
12 . The magnetic mine countermeasure payload device of claim 1 , wherein the rotational shaft is rotated at at least one of a fixed AC frequency, and a variable AC frequency.
13 . The magnetic mine countermeasure payload device of claim 1 , wherein the power source is at least one of a battery, an AC power source, and a DC power source.
14 . The magnetic mine countermeasure payload device of claim 1 , wherein the plates are at least one of round, square, rectangular, hexagonal, and multi-polygonal.
15 . The magnetic mine countermeasure payload device of claim 1 , wherein the device is fixed in a vessel and the vessel is rotated in at least one of a fixed angular rotation, and a variable angular rotation, thereby creating an AC magnetic signature of the array.
16 . A magnetic mine countermeasure payload device comprising: a non-magnetic plate, magnetic elements, each having a north magnetic pole and a south magnetic pole, the magnetic elements affixed to the plate in a magnetic array, wherein when the array is rotated, an AC magnetic moment in the magnetic mine countermeasure payload device is generated, and when the array is not rotated, a DC magnetic moment in the device is generated.
17 . The magnetic mine countermeasure payload device of claim 16 , wherein the magnetic elements include at least one of a permanent magnet, and a superconducting trapped flux magnet.
18 . The magnetic mine countermeasure payload device of claim 16 , wherein the array is rotated at at least one of a constant angular velocity, and variable angular velocity.
19 . The magnetic mine countermeasure payload device of claim 16 , wherein multiple plates are aligned in at least one of a parallel configuration, and an anti-parallel configuration.
20 . The magnetic mine countermeasure payload device of claim 16 , further comprising a hermetic water-tight container configured to house the magnetic mine countermeasure payload.

Description

GOVERNMENT RIGHTS This invention was made with U.S. Government support under contract HR001121C0063 and HR001122C0149 awarded by the Defense Advanced Research Projects Agency (DARPA) The government has certain rights in this invention. FIELD This disclosure relates to the field of magnetic mine sweeping (M-MS) or magnetic mine countermeasures (M-MCM). More particularly, this invention relates to the use of permanent type magnets and high temperature superconducting (HTS) trapped flux magnets to generate both AC and DC magnetic signatures used in magnetic mine sweeping devices. Introduction Magnetic Mine Sweeping, sometimes referred to as Magnetic Mine Countermeasures (M-MCM), is useful in applications where both steady-state magnetic fields (here on B-field) and time-changing magnetic fields (here on AC B-fields or dB/dt) are used to trigger magnetic influence mines (MIM). For the purposes of clarity, brevity, and enablement of the embodiments described in this disclosure, the terms steady-state, static, fixed, stationary, time independent, and direct current (DC) generally have the same meaning, and are used interchangeably throughout this disclosure. Likewise, for the purposes of clarity, brevity, and enablement of the embodiments described in this disclosure, the terms time-dependent, time-varying, dB/dt, and alternating current (AC) B-fields, have the same general meaning and are used interchangeably throughout this disclosure. M-MCM devices can be mounted on a wide variety of naval platforms, including but not limited to manned surface vessels (MSV), unmanned surface vessels (USV), unmanned underwater vessels (UUV), towable arrays, and other types of mine sweeping vessels. Traditional M-MCM devices from the prior art typically involve one of two magnetic mine sweeping approaches: 1) long-length, high current cables dragged behind a MSV, or 2) large diameter electro-magnets mounted on board an MSV or USV. For the former, long-length, high ampacity cables are typically dragged behind surface vessels and perform sweep patterns over the specified area to be cleared of MIMs. These long-length, high ampacity cables are typically made of heavy gauge copper wire or aluminum wire, and are quite heavy and cumbersome to handle. During mine sweeping operations, the heavy cables are first uncoiled from their storage spool, mounted to the rear of the MSV, into the surrounding sea water. The cables are then energized with high currents to generate a corresponding B-field in the nearby vicinity of the cable. The B-field emanating from the cable falls off in magnitude as 1/r, where r is the radius of the cable. In this approach to magnetic mine sweeping, the electrically conductive sea water is used as a return path to the negative polarity (−) side of the power supply that is energizing the cable. The B-field emanating from the cable is used to detonate MIMs near the cable as the MSV performs its sweep patterns. After the magnetic sweep operation is performed, the long length cables are wound back up on a large-diameter spool, and stored on the mine sweeping vessel. The second approach is to mount a large electro-magnet on the deck of an MSV. For this type of M-MCM operation, typically a superconducting electro-magnet is used instead of a normal-resistive copper magnet, because the superconducting magnet, wound with its zero or near zero electrical resistance superconducting wire, has a much higher current density (J in A/m2), and hence would be far lighter and require less electrical power consumption than an equivalent resistive copper electro-magnet possessing the same magnetic dipole moment. In this approach to magnetic mine sweeping, once the superconducting electro-magnet is energized, the MSV performs its sweep pattern over the area to be cleared of MIM. When an MIM is magnetically influenced by the B-field emanating from the surface-mounted superconducting electro-magnet, the MIM detonates. Due to the large spatial magnetic signature (i.e., the effective range) of the superconducting electro-magnet, the detonation typically occurs at a distance far enough away as not to severely damage the MSV. While not bound by theory, the magnetic dipole moment (m) in units of A-m2 of this type of electro-magnet is given by: m=N*I*Aeff[1] where N is the number of turns in the electro-magnet, I is magnet's current (in Amps (A), and Aeff is the effective cross sectional area of the electro-magnet. Thus, the larger the diameter of the electro-magnet, the larger the magnetic dipole moment (M), and hence the larger the effective range of the MSV, which translates to fewer sweeps per unit area. Similarly, the larger the number of turns (N), or the larger the current (I) flowing in the conductor of the electro-magnet, or both, the larger the dipole magnetic moment. To increase the current (I) flowing in the electro-magnetic, superconducting wire is typically used because of its higher current density (J) and zero or nearly zero el