SYSTEM FOR DAMPING UNWANTED MOTOR MOVEMENT

An electric motor system, which may be included in an aircraft, includes a multi-phase motor, a multi-phase inverter circuit, and a plurality of motor brake switches. The multi-phase inverter circuit is coupled to each phase of the multi-phase stator and is adapted to be coupled to a high-side voltage node and a circuit common node. Each motor brake switch is associated with, and is connected in series between, the circuit common node and a different one of the phases. Each motor brake switch is configured to be in an open state when energized and in a closed state when deenergized. When the motor brake switches are in the open state, the motor brake switches do not connect the associated phases to the circuit common node, and when the motor brake switches are in the closed state, the motor brake switches connect the associated phases to the circuit common node.

TECHNICAL FIELD

The present disclosure relates to unwanted motor movement and, more specifically, to a system for damping unwanted motor movement when unpowered, especially with regard to aircraft flight control surfaces when parked on-ground or during in-flight aircraft operation.

BACKGROUND

In the emerging urban air mobility (UAM)/light aircraft market, as well as some regional and larger commercial aircraft markets, the aircraft are electrically operated and, when on the ground and unpowered, can be susceptible to gust loads on the control surfaces. Thus, there is a need to provide a means for dampening the movement of the control surfaces against these gust loads during on-ground, unpowered conditions. In addition to on-ground, unpowered conditions, there may be times when it is desirable to dampen the movement of an unpowered system for one or more control surfaces during in-flight operations.

There are various challenges associated with implementing control surface dampening in the above-mentioned aircraft markets. For example, the mechanism used should not continuously draw current from the aircraft batteries. The mechanism should also be lightweight and relatively small. It should also preferably be a relatively low-cost solution. The present disclosure addresses at least these needs.

BRIEF SUMMARY

In one embodiment, an electric motor system includes a multi-phase motor, a multi-phase inverter circuit, and a plurality of motor brake switches. The multi-phase motor has a multi-phase stator and a rotor. Each phase of the multi-phase stator is configured to be selectively energized to thereby generate a rotating magnetic field that causes the rotor to rotate. The multi-phase inverter circuit is coupled to each phase of the multi-phase stator and is adapted to be coupled to a high-side voltage node and a circuit common node. The multi-phase inverter circuit is configured to selectively couple each phase of the multi-phase stator in series between the high-side voltage node and the circuit common node. Each motor brake switch is associated with, and is connected in series between, the circuit common node and a different one of the phases. Each motor brake switch is configured to be in an open state when energized and in a closed state when deenergized. When the motor brake switches are in the open state, the motor brake switches do not connect the associated phases to the circuit common node, and when the motor brake switches are in the closed state, the motor brake switches connect the associated phases to the circuit common node.

In another embodiment, a flight control surface movement and damping control system includes a flight control surface and an electric motor system. The flight control surface is coupled to receive a drive torque and, in response to the drive torque, to move to a flight control surface position. The electric motor system is coupled to the flight control surface and is configured to selectively supply the drive torque to the flight control surface. The electric motor system includes a multi-phase motor, a multi-phase inverter circuit, and a plurality of motor brake switches. The multi-phase motor has a multi-phase stator and a rotor. Each phase of the multi-phase stator is configured to be selectively energized to thereby generate a rotating magnetic field that causes the rotor to rotate and supply the drive torque. The multi-phase inverter circuit is coupled to each phase of the multi-phase stator and is adapted to be coupled to a high-side voltage node and a circuit common node. The multi-phase inverter circuit is configured to selectively couple each phase of the multi-phase stator in series between the high-side voltage node and the circuit common node. Each motor brake switch is associated with, and is connected in series between, the circuit common node and a different one of the phases. Each motor brake switch is configured to be in an open state when energized and in a closed state when deenergized. When the motor brake switches are in the open state, the motor brake switches do not connect the associated phases to the circuit common node, and when the motor brake switches are in the closed state, the motor brake switches connect the associated phases to the circuit common node.

In yet another embodiment, in an aircraft having a flight control system that includes a flight control surface and an electric motor system coupled to the flight control surface, and wherein the electric motor system includes: (i) a multi-phase motor having a multi-phase stator and a rotor, each phase of the multi-phase stator configured to be selectively energized to thereby generate a rotating magnetic field that causes the rotor to rotate and supply a drive torque to the flight control surface; (ii) a multi-phase inverter circuit coupled to each phase of the multi-phase stator, the multi-phase inverter circuit adapted to be coupled to a high-side voltage node and a circuit common node, the multi-phase inverter circuit configured to selectively couple each phase of the multi-phase stator in series between the high-side voltage node and the circuit common node; and (iii) a plurality of motor brake switches, each motor brake switch associated with, and connected in series between, the circuit common node and a different one of the phases, each motor brake switch configured to be in an open state when energized and in a closed state when deenergized, a method to selectively damp movement of the flight control surface includes the steps of: selectively energizing the motor brakes switches, whereby the motor brake switches are in the open state and do not connect the associated phases to the circuit common node, and selectively deenergizing the motor brake switches, whereby the motor brake switches are in the closed state and connect the associated phases to the circuit common node, thereby damping movement of the flight control surface.

Furthermore, other desirable features and characteristics of the flight control surface movement and damping control system and method will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the preceding background.

DETAILED DESCRIPTION

Referring first toFIG.1, a perspective view of one embodiment of an aircraft100is depicted. It will be appreciated that the aircraft100may be configured as any one of numerous types of aircraft, such as a helicopter, an airplane, or a UAV aircraft. In the depicted embodiment, however, the aircraft100is configured as a UAM aircraft and includes a fuselage102and a plurality of flight control surfaces104. The flight control surfaces104are movably mounted on wings103(103-1,103-2) that are coupled to the fuselage102. In some embodiments, one or more flight control surfaces104may also be movably mounted on the empennage105. Each flight control surface104is coupled to receive a drive torque and, in response to the drive torque, moves to a flight control surface position.

Though not depicted inFIG.1, each flight control surface104selectively receives the drive torque from, and is thus moved to a flight control surface position via, an electric motor system. As will be described momentarily, the electric motor system not only implements flight control surface movement, it also selectively implements flight control surface movement damping. A functional block diagram of one embodiment of a motor control system for a single flight control surface104is depicted inFIG.2and will now be described.

The electric motor system200is disposed at least partially on or within various portions of the aircraft100. For example, all or portions of the electric motor system200may be disposed within one or more of the fuselage102, the wing103, or the empennage105. The electric motor system200is coupled to, and is configured to selectively supply the drive torque to, the flight control surface104. To implement this functionality, the electric motor system200includes a multi-phase motor202, a multi-phase inverter circuit204, and a plurality of motor brake switches206. The multi-phase motor202, as depicted inFIG.3, includes a multi-phase stator302and a rotor304. Each phase of the multi-phase stator302is configured to be selectively energized, via the multi-phase inverter circuit204, to thereby generate a rotating magnetic field. The rotating magnetic field in turn causes the rotor304to rotate and supply the drive torque to the flight control surface104.

In the depicted embodiment, it is seen that the drive torque is supplied to the flight control surface104via a gearbox203that is coupled between the multi-phase motor202and the flight control surface104. It will be appreciated that in other embodiments, the gearbox203may not be included. It will additionally be appreciated that the multi-phase motor202may be implemented using any one of numerous types of multi-phase motors. In the depicted embodiment, however, the multi-phase motor202is implemented using a 3-phase permanent magnet synchronous motor (PMSM).

The multi-phase inverter circuit204is coupled to each phase of the multi-phase stator302. The multi-phase inverter circuit204is coupled to a high-side voltage node208and a circuit common node212. In this regard, and asFIG.2also depicts, an inverter power source214is electrically coupled to the high-side voltage node208and the circuit common node212. The inverter power source214supplies DC voltage to the multi-phase inverter circuit204, which converts the DC voltage to multi-phase AC voltage and supplies the multi-phase AC voltage to the multi-phase motor202. More specifically, the multi-phase inverter circuit204, as is generally known, is configured to selectively couple each phase of the multi-phase stator302in series between the high-side voltage node208and the circuit common node212.

It will be appreciated that the multi-phase inverter circuit204may be implemented using any one of numerous known inverter circuit topologies. In the depicted embodiment, however, and as shown inFIGS.3and4, the multi-phase inverter circuit204is implemented using a 3-phase inverter circuit that comprises six power transistors306, which are controllably switched, via a motor controller213(seeFIG.2), to selectively couple each phase of the multi-phase stator302in series between the high-side voltage node208and the circuit common node212.

Before proceeding further, it is noted that the multi-phase inverter circuit204depicted inFIGS.3and4additionally includes a DC link capacitor308. When included, the DC link capacitor308, as is generally known, filters and smooths out the DC voltage between the high-side voltage node208and the circuit common node212.

Each of the motor brake switches206is associated with, and is connected in series between, the circuit common node212and a different one of the phases of the multi-phase motor202. Each motor brake switch206is configured to be in an open state when it is energized, and to be in a closed state when it is deenergized. When the motor brake switches206are in the open state, which is the state depicted inFIG.3, the motor brake switches206do not connect the associated phases to the circuit common node212. However, when the motor brake switches are in the closed state, which is the state depicted inFIG.4, the motor brake switches206connect the associated phases to the circuit common node212. It will be appreciated that the motor brake switches206may be implemented using any one of numerous known types of switches that implement this functionality. For example, the motor brake switches206could be implemented using any one of numerous known types of depletion mode transistors, such as, for example, junction field effect transistors (JFETs), SiC FETs, or metal-oxide semiconductor field effect transistors (MOSFETs), just to name a few. In the depicted embodiment, however, each motor brake switch206is a depletion mode MOSFET.

Regardless of how the motor brakes switches206are specifically implemented, it is generally known that when the phases of the multi-phase motor202are connected to the circuit common node212, any motor back EMF generated by unwanted movement of the multi-phase motor202will be damped. This unwanted movement can result from, for example, wind gusts acting on the flight control surface104when the aircraft100is on the ground and the associated electric motor system200is deenergized. The unwanted movement can also result from aerodynamic forces acting on the flight control surface when the aircraft100is in flight and the associated electric motor system200is deenergized. Thus, as used herein, the electric motor system200and flight control surface104may also be referred to as a flight control surface movement and damping control system.

AsFIG.2also depicts, the electric motor system200, at least in the depicted embodiment, additionally includes motor brake switch control logic216. The motor brake switch control logic216is electrically coupled to each motor brake switch206and is configured to selectively energize and de-energize each motor brake switch206. Although the motor brake switch control logic216may be variously configured to implement this functionality, in the depicted embodiment it includes enable logic218and a motor brake switch power source222. The enable logic218is configured to selectively supply a power source enable signal224. More specifically, the enable logic218is adapted to receive an enable signal226and is configured to selectively supply the power source enable signal224. Even more specifically, the enable logic218is configured such that when the enable signal226is supplied to the enable logic218, the enable logic218supplies the power source enable signal224. Conversely, when the enable signal226is not supplied to the enable logic218, the enable logic218does not supply the power source enable signal224.

The motor brake switch power source222is coupled to receive the power source enable signal224from the enable logic218and is electrically coupled to each of the motor brake switches206. The motor brake switch power source222is configured, in response to receiving the power source enable signal224, to energize each motor brake switch206. The motor brake switch power source222is further configured, in response to not receiving the power source enable signal224, to deenergize each motor brake switch206. Thus, when the enable logic218is supplying the power source enable signal224, the motor brake switches206are in the open state and thus do not connect the associated phases to the circuit common node212.