Portable service controller for electro-mechanical actuators

A portable service controller for controlling an electro-mechanical actuator, the portable service controller includes a battery configured to power the portable service controller and a user interface configured to receive input from a user and to responsively generate an input signal. The portable service controller also includes a phase sequencer configured to convert the input signal into a series of timed output signals and a driver circuit configured to convert the series of timed output signals into inverter gating signals. The portable service controller further includes a three-phase brushless motor inverter configured to convert inverter gating signals into control signals for a brushless motor of the electro-mechanical actuator. The portable service controller contains a motor brake on/off circuitry for engaging and disengaging the electro-mechanical actuator motor brake. The battery, the three-phase brushless motor inverter, the driver circuit, the phase sequencer and the user interface are all disposed in a housing.

BACKGROUND OF THE INVENTION

The present disclosure relates to the field of electro-mechanical actuators, and more specifically, to a portable service controller for electro-mechanical actuators.

Electro-mechanical actuators are currently used in a wide variety of applications. For example, electro-mechanical actuators are currently used in machine tools industrial machinery, computer peripherals such as disk drives and printers, valves and dampers, and in many other places where linear motion is required. In general, electro-mechanical actuators typically operate by converting the rotary motion of an electric motor into linear displacement of an actuator.

Aircraft typically include multiple electro-mechanical actuators that are used to control the operations of various parts of the aircraft, such as brakes, flaps, etc. In general, these electro-mechanical actuators can be operated by a controller built into the electronics system of the aircraft or by a high voltage service controller that is configured to be plugged into a 120/240 AC volt power source.

When an aircraft is on the ground and actuation via the electro-mechanical actuator controller is not possible (for instance due to a failed electro-mechanical actuator controller, a failed wire bundle or a general lack of electrical aircraft power), the electro-mechanical actuators are typically actuated with the help of a ground-station electro-mechanical actuator controller that is powered from an A/C power outlet (110VAC to 480VAC). In situations where an electro-mechanical actuator is ‘locked under force’ and a ground station electro-mechanical actuator controller is not available and/or A/C power cannot be supplied, electro-mechanical actuator unlocking is currently accomplished via mechanical actuation of the motor shaft or other members of the actuator's mechanism. Mechanical actuation requires the use of a special tool that is inserted into the electro-mechanical actuator, which typically requires the removal of fasteners, safety wires, access panels and seals. Some electro-mechanical actuators have a motor brake to hold the actuator in place. Therefore, the motor brake may need to be released in order for the actuator to be unlocked.

BRIEF DESCRIPTION OF THE INVENTION

According to one embodiment, a portable service controller for controlling an electro-mechanical actuator includes a battery configured to power the portable service controller and a user interface configured to receive input from a user and to responsively generate an input signal. The portable service controller also includes a phase sequencer configured to convert the input signal into a series of timed output signals and a driver circuit configured to convert the series of timed output signals into inverter gating signals. The portable service controller further includes a three-phase brushless motor inverter configured to convert inverter gating signals into control signals for a brushless motor of the electro-mechanical actuator. The battery, the three-phase brushless motor inverter, the driver circuit, the phase sequencer, the motor brake circuit, and the user interface are all disposed in a housing.

Accordingly to another embodiment, a portable service controller includes a user interface configured to receive input from a user and to responsively generate an input signal and a phase sequencer configured to convert the input signal into a series of timed output signals based on a phase sequencing table. The portable service controller also includes a driver circuit configured to convert the series of timed output signals into inverter gating signals and a three-phase brushless motor inverter configured to convert inverter gating signals into control signals suitable for controlling a brushless motor. The three-phase brushless motor inverter, the driver circuit, the phase sequencer, the motor brake circuit, and the user interface are all disposed in a housing.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, a portable service controller is provided to simplify the removal of electro-mechanical actuators from the brakes of aircraft in the field (i.e., from an aircraft parked on the tarmac). While the portable service controller disclosed is primarily discussed as being used for aircraft brake electro-mechanical actuators, it will be appreciated by those of ordinary skill in the art that the portable service controller can be used with other aircraft-installed electro-mechanical actuators (e.g., flap actuators, aileron actuators, etc.) to simplify installment, removal or adjustment of those electro-mechanical actuators). In addition, the portable service controller may be used for controlling other non-aircraft based electro-mechanical actuators.

Referring now toFIG. 1, a system100having an electro-mechanical actuator102and a portable service controller104in accordance with an embodiment of the disclosure is shown. As illustrated the electro-mechanical actuator102is coupled to the portable service controller104via a cable110, which is configured to connect to an electro-mechanical actuator connector132and a portable service controller connector130. The portable service controller102includes a housing106and a user interface108configured to facilitate user operation of the portable service controller102. The user interface108may include a plurality of controls to turn on/off the electro-mechanical actuator102, rotate the electro-mechanical actuator102, and to adjust the speed of the rotation of the electro-mechanical actuator102, and to engage or disengage the motor brake of the electromechanical actuator102. The user interface108may include a variety of knobs, switches, touch screen elements, or the like to allow the user to control the electro-mechanical actuator102.

In one embodiment, the portable service controller104is a portable hand held device that is configured to be connected to a variety of electro-mechanical actuator102. The portable service controller104may be used to control the operation of an electro-mechanical actuator102when the primary controller for the electro-mechanical actuator102has failed or lost power. In addition, the portable service controller104may include a battery sufficient to power both portable service controller104and the electro-mechanical actuator102. Accordingly, the portable service controller104is configured to be used to control electro-mechanical actuators102when a high voltage power source is not readily available.

Referring now toFIG. 2, a system200having an electro-mechanical actuator202and a portable service controller204in accordance with an embodiment of the disclosure is shown. As illustrated, the electro-mechanical actuator202includes a brushless motor220which is coupled to a motor brake226and coupled to an output device222, such as a drive shaft or piston. The portable service controller204includes a battery210, a three-phase brushless motor inverter212, a driver circuit214, a phase sequencer216, an on-off switch224, motor brake circuit228and a motor brake on-off switch232, all of which are disposed in a single housing, as shown inFIG. 1. In one embodiment, the brushless motor220of the electro-mechanical actuator202is operated in ‘position-sensorless’ or ‘open-loop’ stepper mode, which reduces the amount of wiring between the electro-mechanical actuator202and the portable service controller204.

In one embodiment, the battery210is a small, low-voltage battery that is suitable to power the portable service controller204and the electro-mechanical actuator202. For example, the battery210may be a twelve volt battery that has a current rate of three to three and a half amperes. The battery210can be either replaceable or rechargeable type battery. In one embodiment, the on-off switch224is configured to selectively turn the portable service controller204on or off In one embodiment, the three-phase inverter212includes a plurality of electronic switches230(e.g., MOSFETs, IGBTs, Bipolar) that are configured to control the current flow between the battery210and the brushless motor220of the electro-mechanical actuator202.

In one embodiment, the driver circuit214is configured to drive the inputs (e.g., gates) of the electronic switches230and to convert an input from the phase sequencer216into appropriate inverter gating signals. In one embodiment, the phase sequencer216is configured to convert operator inputs (e.g., motor direction, motor speed) received from the user interface208into a series of timed output signals, which are provided to the drive circuit214. In one embodiment, the phase sequencer216may utilize a phase sequencing table218to convert the operator inputs into the timed output signals.

In one embodiment, the brushless motor220of the electro-mechanical actuator204is operated without rotor position feedback. The portable service controller204provides individual step commands to the brushless motor220at a steadily increasing rate until the step rate has reached the desired motor speed. By ramping up the step rate in this manner, the brushless motor220follows the step request without losing synchronicity.FIG. 3Ais depicts a step sequence for operating the brushless motor220in a clockwise rotation. Likewise,FIG. 3Bdepicts a step sequence for operating the brushless motor220in a counter-clockwise rotation. It will be appreciated by those of ordinary skill in the art that the step sequences shown are for illustration purposes only and that any suitable step sequence may be used to control the operation of the brushless motor220.

Referring now toFIG. 4, a block diagram of one embodiment of a phase sequencer400is shown. In one embodiment, the phase sequencer400includes a control interface402, a voltage controlled oscillator404and a ring counter406. In one embodiment, the control interface402is configured to receive one or more input signals from a user and to convert the input signals to a ramp voltage. The ramp voltage is provided to the voltage controlled oscillator404, which responsively produces a voltage-to-frequency signal that is provided to the ring counter406. The frequency of the voltage controlled oscillator404is used to clock the ring counter406. In one embodiment, the ring counter406is configured to count to three and then reset, this sequence can be repeated until the stop input is received.

Referring now toFIG. 5, a timing diagram illustrating the signal waveforms of the phase sequencer in accordance with an embodiment of the disclosure is shown. Waveform1is the ramp voltage that is provided to the voltage controlled oscillator404. Waveform2, waveform3and waveform4are the outputs from the ring counter406into the Driver Circuit214. Waveform2, waveform3and waveform4represent the rotor step sequencing of the three motor phases of the EMA from slow speed to a higher speed.

Referring toFIG. 6, the motor brake circuit shows a motor brake on/off switch which has a momentary action that feeds the motor brake driver circuit610and the motor brake voltage boost circuit. The motor brake driver circuit closes switches A and B′ when the motor brake on/off switch goes to the ‘on’ state to engage the motor brake. The motor brake driver circuit closes switches A′ and B when the motor brake on/off switch goes to the ‘off’ state to disengage the motor brake. The Motor Brake Voltage Boost circuit steps up the battery voltage to a voltage level required to engage or disengage the Motor Brake.