B64G1/286

MODEL PREDICTIVE CONTROL OF SPACECRAFT
20190049998 · 2019-02-14 ·

A spacecraft including a set of thrusters for changing a pose of the spacecraft. At least two thrusters mounted on a gimbaled boom assembly and are coupled together sharing the same gimbal angle. A model predictive controller (MPC) to produce a solution for controlling thrusters of the spacecraft by optimizing a cost function over a receding horizon using a model of dynamics of the spacecraft effecting a pose of the spacecraft and a model of dynamics of momentum exchange devices of the spacecraft effecting an orientation of the spacecraft. A modulator to modulate magnitudes of the thrust of the coupled thrusters determined by the MPC as pulse signals specifying ON and OFF states of each of the coupled thruster, wherein the ON states of the coupled thrusters sharing the same gimbal angle do not intersect in time. A thruster controller to operate the thrusters according to their corresponding pulse signals.

MODEL PREDICTIVE CONTROL OF SPACECRAFT
20190049999 · 2019-02-14 ·

A control system for controlling an operation of a spacecraft. A model predictive controller (MPC) produces a solution for controlling thrusters of the spacecraft. The MPC optimizes a cost function over a finite receding horizon using a model of dynamics of the spacecraft effecting a pose of the spacecraft and a model of dynamics of momentum exchange devices of the spacecraft effecting an orientation of the spacecraft. The optimization is subject to hard and soft constraints on angles of thrusts generated by thrusters. Further, the hard constraints require the angles of thrusts in the solution to fall within a predetermined range defined by the hard constraints. The soft constraints penalize the solution for deviation of the angles of thrusts from nominal angles corresponding to a torque-free thrust passing through the center of the mass of the spacecraft. A thruster controller operates the thrusters according to the solution of the MPC.

High control authority variable speed control moment gyroscopes

A variable speed control moment gyroscope (VSCMG) having a desired offset between the center of mass of the gimbal frame and the center of mass of the flywheel. This gives the VSCMG a higher control authority than an otherwise identical VSCMG without the desired offset at identical gimbal and flywheel rotation rates. Thus the VSCMG generates more angular momentum and torque than an otherwise identical VSCMG without the desired offset at identical gimbal and flywheel rotation rates and per the same unit power consumption. The VSCMG can be operated without any control singularities in a map between the gimbal rate and/or the flywheel rate and the angular momentum or torque produced by the VSCMG. The desired offset is typically at least an order of magnitude greater than an offset between the center of mass of the gimbal frame and the center of mass of the flywheel occurring during manufacture of the VSCMG due to manufacturing tolerances.

CONTROL MOMENT GYROSCOPE

A control moment gyroscope includes: an inner gimbal; a rotor that is held by the inner gimbal to be rotatable around a spin axis; a spin motor that is disposed on the inner gimbal, and that rotates the rotor around the spin axis; a stator that holds the inner gimbal to be rotatable around a gimbal axis that is perpendicular to the spin axis; gimbal bearings that are disposed between the inner gimbal and the stator to face each other from opposite sides of a plane that is perpendicular to the gimbal axis and that includes the spin axis, to be in contact with the plane in question, or to include the plane in question; and a torque module that is disposed on the stator, and that rotates the inner gimbal around the gimbal axis.

Concurrent station keeping, attitude control, and momentum management of spacecraft

An operation of a spacecraft is controlled using an inner-loop control determining first control inputs for momentum exchange devices to control an orientation of the spacecraft and an outer-loop control determining second control inputs for thrusters of the spacecraft to concurrently control a pose of the spacecraft and a momentum stored by the momentum exchange devices of the spacecraft. The outer-loop control determines the second control inputs using a model of dynamics of the spacecraft including dynamics of the inner-loop control, such that the outer-loop control accounts for effects of actuation of the momentum exchange devices according to the first control inputs determined by the inner-loop control. The thrusters and the momentum exchange devices are controlled according to at least a portion of the first and the second control inputs.

Near-zero revolutions per minute (RPM) sensing
10175065 · 2019-01-08 · ·

A rotor assembly for deployment within a momentum control device that enables near-zero revolutions per minute (RPM) sensing, and method for making same, are provided. The provided rotor assembly utilizes a magnet coupled to the rotor shaft and a stationary sensor element to detect magnetic flux from the magnet and derive reliable near zero RPM therefrom.

Large-scale space-based solar power station: multi-scale modular space power

A space-based solar power station, a power generating satellite module and/or a method for collecting solar radiation and transmitting power generated using electrical current produced therefrom is provided. Each solar power station includes a plurality of satellite modules. The plurality of satellite modules each include a plurality of modular power generation tiles including a photovoltaic solar radiation collector, a power transmitter and associated control electronics. The power transmitters can be coordinated as a phased array and the power generated by the phased array is transmitted to one or more power receivers to achieve remote wireless power generation and delivery. Each satellite module may be formed of a compactable structure capable of reducing the payload area required to deliver the satellite module to an orbital formation within the space-based solar power station.

Control moment gyroscope
10139226 · 2018-11-27 · ·

The objective of the present invention is to provide a control moment gyroscope which can be provided in a limited space since the volume thereof can be reduced without change in performance by optimizing the shapes and mounting positions of each component. To this end, the control moment gyroscope of the present invention is a control moment gyroscope for generating torque in the orthogonal directions to both of two shafts which are perpendicularly disposed to each other by rotating the two shafts, and the control moment gyroscope comprises: a gimbal motor formed in a hollow cylinder shape and supplying momentum; spin motor provided inside the gimbal motor and supplying momentum in a perpendicular direction to the momentum of the gimbal motor; and a flywheel provided in the inside of the gimbal motor and supplied with the rotational force of the gimbal motor and the rotational force of the spin motor.

Spin and tilt control of a multi-degree of freedom electromagnetic machine
10118716 · 2018-11-06 · ·

A multi-degree-of-freedom electromagnetic machine includes a first structure, a second structure, and a control. The first structure is configured to rotate about a spin axis and about a tilt axis that is perpendicular to the spin axis, and includes a first spin conductor, a second spin conductor, and a tilt conductor, which together form a general shape of a surface. The second structure is disposed adjacent to the first structure and includes a plurality of magnets. The control is configured to controllably supply alternating current (AC) to the first and second spin conductors and direct current (DC) to the tilt conductor, wherein the first structure continuously rotates about the spin axis in response to the AC being supplied to the first and second spin conductors, and rotates about the tilt axis to a tilt position in response to the DC being supplied to the tilt conductor.

Control moment gyroscope module for satellites

A control moment gyroscope (CMG) module for use in a satellite comprising a CMG, the CMG comprising a flywheel assembly mounted on a gimbal assembly, the flywheel assembly comprising a flywheel rim, a flywheel spokes member and a flywheel shaft, the flywheel rim circumscribing the flywheel shaft, and the flywheel spokes member extending between the flywheel shaft and the flywheel rim. The gimbal assembly comprises at least one gimbal and a spin motor, the spin motor for rotating the flywheel assembly about a first axis. The CMG further comprises a torque shaft and a torque motor for rotating the at least one gimbal about a second axis. The CMG module further comprises a hermetic first shell housing; and a hermetic second shell housing; wherein the second shell housing is joined to the first shell housing by a hermetic seal to form an airtight interior of the CMG module, the interior of the CMG module containing the CMG.