Electromechanical servo controller, swashplate system with at least four electromechanical servo controllers, and rotorcraft

Abstract

The invention relates to a linear electromechanical servo controller (10) comprising a power rod (21) which is movable in translation. The servo controller (10) comprises a single linear electric actuator (20) having at least one electric motor (30) connected with the power rod (21) by a mechanical linkage (25), the servo controller (10) comprising an anchor (40) fixed to the electric actuator (20), the at least one electric motor (30) being controlled by a computer (60), the anchor (40) having an anchor rod (42) which is movable in translation, the anchor (40) having an anchor brake (50) configured to immobilize the anchor rod (42) relative to the electric actuator (20) in a normal mode of operation or to allow the electric actuator (20) to move relative to the anchor rod (42) in a safe mode of operation upon request of the computer (60).

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of FR2105319, filed on May 21, 2021, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to an electromechanical servo controller, a swashplate system having at least four electromechanical servo controllers, and a rotorcraft.

[0004] A rotorcraft includes at least one rotating wing. The rotating wing includes a rotor with multiple blades. The rotorcraft may include a swashplate system for periodically and collectively changing the pitch of the rotor blades.

[0005] Such a swashplate system may include a fixed swashplate connected to each blade of the rotor via a mechanism. The fixed swashplate is capable of translating along a first axis to collectively change the pitch of the rotor blades, and can oscillate about a second and a third axis to periodically change the pitch of the blades, i.e., according to the azimuth angle of each blade relative to the axis of rotation of the rotor.

[0006] According to a known embodiment, the fixed swashplate is a non-rotating swashplate that does not rotate relative to the rotor's axis of rotation. Therefore, the fixed swashplate mates with the rotating swashplate of the mechanism. The rotating swashplate is connected to the blades via a corresponding connecting rod. The non-rotating swashplate can be carried by a ball joint that slides on a guide tube. The rotating swashplate is connected to the non-rotating swashplate via a bearing that imparts only one rotational degree of freedom to the rotating swashplate relative to the non-rotating swashplate. The non-rotating swashplate, rotating swashplate, and ball joint can translate in unison to collectively change the blade pitch. The rotating and non-rotating swashplates can also tilt in unison relative to the ball joint to periodically change the blade pitch.

[0007] Regardless of how the fixed swashplate is connected to the rotor blades, the swashplate system can include at least three servo controllers that are hinged to the fixed swashplate to move the fixed swashplate.

[0008] The servo controller may include a linear hydraulic actuator, i.e., an actuator that extends or retracts in response to a command from a hydraulic selector valve. For safety reasons, the servo controller may include at least two hydraulic bodies that cooperate with the same power rod in a system with a stationary body, or with the same anchor rod in a system with a moving body.

[0009] Alternatively, the servo controllers can be electromechanical, comprising at least one electromechanical actuator. Such electromechanical servo controllers are actually beneficial because they do not require the installation of a hydraulic system, but they are at risk of jamming. For safety reasons, each servo controller can comprise two linear electric actuators arranged in parallel or in series. Such a solution is beneficial, but it has at least six electric actuators, which impacts the spatial requirements and the weight of the system.

[0010] Moreover, a servo controller with two electric actuators in series is difficult to install due to its length, especially in replacement of an existing hydraulic servo controller. In addition, in a system with three servo controllers, the parts connecting the electric actuators to each other and to the support and to the fixed swash plate are critical.

[0011] A servo controller with two electric actuators in parallel has a considerable width. Moreover, such a servo controller requires a specific mechanism to connect its electric actuators to the fixed swash plate. Such a mechanism is also at risk of jamming.

[0012] Therefore, each electromechanical or hydraulic servo controller can comprise at least two working subassemblies (i.e. at least two hydraulic bodies or two electric actuators) so as to have its own backup system. BACKGROUND

[0013] Patent FR 2 438 586 describes a system with at least four servo controllers, each servo controller having a hydraulic pump associated with a hydraulic actuator. Three servo controllers are in use at a given time, the other servo controller(s) being considered as passive backup servo controllers that can become active in case of failure of one of the servo controllers in use.

[0014] Document FR 2 684 953 describes a system with four hydraulic servo controllers. Each servo controller has a powered actuator, an anchoring system and a servo valve. In normal operating mode, three servo valves are active and one servo valve is passive.

[0015] Document US 2020 / 290 729 Al discloses a linear electromechanical system with two connectors, a rod and at least one actuating device configured to vary the distance between the connectors.

[0016] Document EP 1 927 543 A2 describes a linear electromechanical servo controller comprising a cylindrical nut threadedly coupled with an output rod.

[0017] Document US 2013 / 119 187 Al describes a system with an electric servo controller hinged to one swash plate of a set of swash plates.

[0018] Document US2010 / 150719A1 discloses a system comprising a hub carrying blades and one electric actuation device arranged in the hub for each blade. The actuation device comprises a housing mounted on the hub and partially housing a linear output shaft.

[0019] Document US2010 / 084517A1 describes a system comprising three electromechanical actuation assemblies arranged under the outer periphery of the swash plate. Each actuation assembly comprises three linear actuation devices and one adder plate and one fixed swash plate bar. SUMMARY

[0020] It is therefore an object of the present invention to propose an electromechanical servo controller to obtain an innovative swash plate system for controlling the pitch of the blades of a rotor, the system having a limited number of servo controllers to optimize weight and cost.

[0021] The present invention therefore relates to a linear electromechanical servo controller comprising a power bar movable in translation, the servo controller being in particular connectable with a fixed swash plate.

[0022] In addition, the servo controller comprises a single linear electric actuator having at least one electric motor connected with the power bar by a mechanical link, the servo controller comprising an anchor fixed to the electric actuator, said at least one electric motor being controlled by a computer, said anchor having an anchor bar movable in translation with respect to the body of the servo controller, the anchor bar being articulable to a fixed support or to a rotating star, said anchor having at least one anchor brake configured to immobilize the anchor bar with respect to the electric actuator in a normal operating mode at the request of the computer and to make the servo controller transparent in a safety operating mode by allowing the electric actuator to move with respect to the anchor bar.

[0023] The anchor bar is therefore independent and separate from the power bar.

[0024] Such a servo controller can therefore become passive and transparent in case of failure. The term "passive" means that the servo controller has no influence, the term "transparent" means that the servo controller also allows the controlled object to move freely. Such a servo controller also makes the swash plate system reliable and robust, not by duplicating the servo controllers, but as a whole.

[0025] In normal operating mode, the anchor is fixed. The electric actuator can extend or retract to move the object, for example to move the fixed swash plate.

[0026] In the safe operating mode, the electric actuator can move relative to the anchor rod under the pressure of the object. The servo controller then follows the movement of the object.

[0027] The servo controller can also comprise one or more of the following features, taken individually or in combination.

[0028] According to one possibility, the electric actuator of the servo controller can comprise a plurality of electric motors cooperating with the same actuator shaft of the mechanical linkage.

[0029] The electric actuator can thus comprise a plurality of electric motors mounted on the same shaft to meet the availability requirements.

[0030] The one or more motors can each comprise a stator surrounding the rotating part and enabling the rotating part to move in a conventional manner relative to the stator upon request.

[0031] According to one possibility compatible with the preceding one, the mechanical linkage of the servo controller can comprise an actuator shaft fixed to the rotating part of the at least one electric motor, the mechanical linkage comprising an actuator converter connected to the actuator shaft and to the power rod, the actuator converter being configured to convert the rotational movement of the actuator shaft into a translational movement of the power rod and vice versa.

[0032] For example, the actuator converter can comprise elements of a ball screw, roller screw or screw / nut system.

[0033] Optionally, the mechanical linkage or indeed the actuator converter can comprise a reduction system. For example, a planetary gear train is arranged between the ball screw and the actuator shaft.

[0034] The actuator converter is a rotation / translation converter for connecting the one or more rotating motors to the power rod, which is able to move in translation relative to the body of the servo controller. If the one or more motors become inoperative in the non-operating mode of the normal operating mode, the rotating part can be rotated by the translational movement of the power rod relative to the body of the servo controller under the pressure of the object controlled by the servo controller. The servo controller then follows the movement of the object, for example the fixed swash plate.

[0035] In the event of a jamming of the electric actuator, the anchor rod can be released by the anchor brake, so that the servo controller follows the movement of the object and thus of the fixed swash plate, if applicable.

[0036] Optionally, the actuator shaft comprises a thread cooperating with the actuator converter, for example a nut, a ball screw, etc.

[0037] According to a possibility compatible with the preceding ones, said anchoring portion can comprise an anchoring shaft rotatable with respect to a support member fixed to said electric actuator, said anchoring portion comprising a reversible anchoring translator connected with said anchoring shaft and said anchoring rod and configured so that a translational movement of the anchoring shaft with respect to the anchoring rod causes a rotational movement of the anchoring shaft and vice versa, said anchoring brake being configured to immobilize said anchoring shaft with respect to the anchoring rod in normal operating mode and to release said anchoring shaft in safety operating mode.

[0038] When the anchoring brake immobilizes the anchoring shaft, the body of the electric actuator is stationary with respect to the anchoring rod.

[0039] Conversely, when the anchoring brake no longer immobilizes the anchoring shaft, the anchoring shaft can rotate freely. The body of the electric actuator can thus move translationally with respect to the anchoring rod, the anchoring shaft rotating about itself.

[0040] The anchoring translator can comprise a ball screw or a roller screw, a screw / nut system, etc.

[0041] Optionally, the anchoring translator can comprise a reduction system. For example, a planetary gear train is arranged between the ball screw and the anchoring shaft.

[0042] The anchoring brake can thus be simple, comprising at least one pad moved by an actuation device to press against a face of the anchoring shaft as required. For example, such a brake can comprise a spring tending to move the pad away from the face of the anchoring shaft and an electromagnet tending to attract said pad when powered, thereby lengthening said spring.

[0043] Alternatively, said anchoring portion can comprise an anchoring shaft fixed to the electric actuator and translationally movable with respect to the anchoring rod, said anchoring brake being configured to connect said anchoring shaft and said anchoring rod in normal operating mode and to disconnect said anchoring shaft and said anchoring rod in safety operating mode.

[0044] This operation is identical to the previous scheme. However, according to this possibility, the anchoring shaft is translationally movable.

[0045] According to a possibility compatible with the preceding ones, said electric actuator of the servo-controller can comprise an actuator brake cooperating with said power rod or an actuator shaft connected with said power rod through an actuator translator.

[0046] Such an actuator brake can be used in the event of a malfunction, for example in the event of failure of at least one electric motor, in order to brake the power rod or the actuator shaft, if provided.

[0047] For example, the actuator brake can be a zero-current brake that is different from the anchoring brake.

[0048] According to a possibility compatible with the preceding ones, the computer can be configured to control the at least one electric motor in a working mode of the normal operation mode and to inhibit the at least one electric motor in a non-working mode of the normal operation mode.

[0049] Thus, in case of failure of the servo controller, the computer can simply render the motor(s) inoperative, for example by cutting the power supply line to the motor(s) or by no longer sending command signals to the motor(s). Thus, in particular in the presence of an actuator converter, the servo controller is passive and transparent. In case of jamming, the servo controller will be in a safe operation mode.

[0050] Thus, two separate devices can render the servo controller passive and transparent.

[0051] According to a possibility compatible with the preceding ones, the servo controller can be able to operate according to a plurality of configurations, the configurations depending on the current operation mode of the servo controller, the current operation mode being able to be a mode corresponding to a normal operation mode or a safe operation mode, the computer can comprise one control model per possible configuration in order to control the servo controller according to at least one received control signal.

[0052] The computer receives at least one control signal sent by a controller, the controller being able to comprise a control interface controlled by a human being and / or an autopilot. For each possible configuration, the computer comprises a model providing a signal to be sent to the servo controller as a function of one or more control signals.

[0053] According to a possibility compatible with the preceding ones, the servo controller can comprise at least one actuator operation sensor cooperating with the power lever and / or the motor and / or the actuator shaft, the actuator operation sensor sending to the computer an actuator operation signal carrying information related to the movement of the power lever relative to the body of the servo controller.

[0054] According to one example, the actuator operation sensor can comprise a current sensor designed to detect an excessive current consumption. The excessive current consumption can mean that the motor(s) cannot move the power lever.

[0055] According to one example, the actuator operation sensor can comprise a rotation sensor arranged on the actuator shaft. If the power lever cannot move in translation, the actuator shaft cannot rotate. For example, the motor(s) can comprise an integrated rotation sensor.

[0056] According to another example, the actuator operation sensor can comprise a position, velocity or acceleration sensor arranged on the power lever. For example, the actuator operation sensor can comprise a linear sensor comprising a measuring rod attached to the power lever and a measuring unit fixed to the body of the servo controller, for example the body of the electric actuator. If the computer sends a command to the electric motor to move the power lever and the actuator operation sensor sends an unvarying signal, the computer infers that the electric motor has failed and can inhibit one or more motors of the servo controller.

[0057] According to a possibility compatible with the preceding ones, each servo controller can comprise at least one anchor operation sensor cooperating with said anchor lever and / or anchor shaft, if provided, said anchor operation sensor sending to the computer an anchor operation signal with information relating to the movement of said anchor lever with respect to the body of the servo controller.

[0058] For example, the anchor operation sensor can comprise a rotation sensor arranged on the anchor shaft, or a position, velocity or acceleration sensor arranged on the anchor lever.

[0059] In the safe operating mode, the computer can be configured to use the anchor operation signal to determine whether the anchor is stuck.

[0060] If stuck, the computer can communicate with an alarm to generate a visual, audible or tactile alarm upon detection of a failure or a stick.

[0061] Furthermore, the swashplate system can comprise at least four electromechanical servo controllers according to the application, each electromechanical servo controller being articulated to the support and to the fixed swashplate to control the pitch of the rotor blades.

[0062] The electric motors of said servo controllers are controlled by a common computer, said anchor of each servo controller having said anchor lever articulated to the support or to the fixed swashplate.

[0063] In practice, the swashplate system comprises at least four electromechanical servo controllers, each electromechanical servo controller having an electric actuator, and possibly only four electromechanical servo controllers. Four servo controllers can be sufficient to obtain a system that is robust to failure.

[0064] In the normal operating mode, each anchor is fixed. The electric actuator can extend or retract to move the fixed swashplate.

[0065] In the safe operating mode, the electric actuator can move with respect to the anchor lever under the pressure of the fixed swashplate. The servo controller then follows the movement of the fixed swashplate.

[0066] Thus, under normal conditions, the computer controls at least three or indeed all servo controllers to extend or retract, which are in the working mode of the normal operating mode. In case of a malfunction or jam, the servo controller in question is suppressed by no longer being controlled during the non-working mode of the normal operating mode, or by releasing its anchor and switching to the safe operating mode, becoming passive and transparent. However, in these cases, at least three servo controllers remain operational and allow the blades of the rotor to be controlled.

[0067] Thus, the swashplate system as a whole becomes robust after a servo controller has failed, unlike a system that is made robust by using multiple actuators for each servo controller.

[0068] Furthermore, the components of the servo controller are not critical, since in the event of a servo controller being switched off, the system still has at least three servo controllers that are operational.

[0069] According to another aspect, such a system can be easily checked before use. Upon command of the operator, the computer can switch the servo controller under test to the safe operating mode. The other servo controllers are controlled to remain stationary and to hold the fixed swashplate in the test position. Thus, the computer can control the electric actuator of the servo controller under test so as to extend it over its entire stroke. Since the fixed swashplate is stationary, the electric actuator of the servo controller under test must move relative to its anchor rod. If it does not move relative to its anchor rod, the servo controller is defective. Such an operation can be performed several times for each servo controller for safety reasons.

[0070] Since the system can operate according to a plurality of configurations, depending on the current operating mode of each servo controller, which can be a mode corresponding to the normal operating mode or to the safe operating mode, the computer can comprise one control model for each possible configuration, in order to control the servo controllers according to at least one received control signal.

[0071] The computer receives at least one control signal sent by a controller, which can comprise a control interface controlled by a human being and / or an autopilot. For each possible configuration, the computer comprises a model that provides the signals to be respectively sent to the servo controllers according to one or more control signals.

[0072] The computer selects the model to be used according to one or more servo controllers that are not operational by default or after a failure, the computer controlling the servo controllers differently according to the applied model to achieve the desired result.

[0073] Furthermore, a rotorcraft can have a rotor comprising a plurality of blades, said rotorcraft possibly comprising a swash plate system according to the present application, the swash plate system having at least four electromechanical servo controllers hinged to a fixed swash plate, the fixed swash plate being connected to each blade by a mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0074] The present application and its advantages will appear more clearly from the following description of embodiments given by way of example and with reference to the drawings in which:

[0075] · Figure 1 is a sectional view showing a servo controller according to the present application;

[0076] · Figure 2 is a view showing an anchoring portion with an anchoring shaft capable of translational movement;

[0077] · Figure 3 is a view showing a vehicle provided with a swash plate system according to the present application;

[0078] · Figure 4 is a view showing the operation of a swash plate system according to the present application;

[0079] · Figure 5 is a view showing the operation of a swash plate system according to the present application; and

[0080] · Figure 6 is a view showing the operation of a swash plate system according to the present application. DETAILED DESCRIPTION

[0081] Elements appearing in more than one figure are given the same reference numerals in each figure.

[0082] Figure 1 An example of a servo controller 10 according to the present application is shown. The servo controller 10 can be arranged within a fixed swash plate system or other type of mechanical system for moving an object, at least one servo controller being able to become passive according to a command. The term "passive" means that the servo controller has no influence on the movement of the object other than friction.

[0083] Regardless of its arrangement, the servo controller 10 is a linear electromechanical servo controller.

[0084] To this end, the servo controller 10 comprises a power rod 21 capable of translational movement along a longitudinal axis with respect to a body 15 of the servo controller 10. The power rod 21 can comprise a fastener 210 hinged to an element to be moved or to a fixed support. In order to extend or retract the power rod 21, the servo controller 10 comprises a single electric actuator 20.

[0085] The electric actuator 20 comprises an actuator body 22. The actuator body 22 is an integral part of the body 15 of the servo-controller 10. The electric actuator 20 further comprises at least one electric motor 30, for example housed in the actuator body 22. The electric motor(s) 30 can be translational or rotational motors connected to the power rod 21 by a mechanical linkage 25.

[0086] For example, the electric motor(s) 30 comprise a stator 32 fixed to the actuator body 22 and a rotating part 31 at least partly housed in the stator 32. In a conventional manner, the electric motor(s) 30 can comprise permanent magnets and electric coils controlled by power electronics. The motor(s) 30 can be of the synchronous motor type. For example, the stator 32 comprises coils and the rotating part 31 comprises permanent magnets.

[0087] The motor(s) can comprise an integrated rotation sensor measuring the rotation of the rotating part 31.

[0088] Furthermore, the mechanical linkage 25 can comprise an actuator shaft 27 engaged with the motor(s) 30. The actuator shaft 27 can extend entirely into the actuator body 22, the power rod 21 being able to extend partly into the actuator body 22. Alternatively, the actuator shaft 27 can extend partly into the actuator body 22. Where appropriate, the actuator shaft 27 can be fixed to the rotating part(s) 31 of the motor(s) 30.

[0089] In addition to the actuator shaft 27, the mechanical linkage 25 can comprise an actuator converter 26 connected to the actuator shaft 27 and to the power rod 21. If there is a rotating motor(s) 30 that rotates the actuator shaft 27, the actuator converter 26 converts the rotational movement of the actuator shaft 27 around a longitudinal axis into translational movement of the power rod 21 along the longitudinal axis, and vice versa.

[0090] To this end, the actuator shaft 27 can comprise threads 28 cooperating with the actuator converter 26 carried by the power rod 21.

[0091] The actuator converter 26 can comprise a ball screw or equivalent, a nut fixed to the power rod, etc., and can even comprise a reduction system, etc.

[0092] Irrespective of these features, the motor(s) 30 can be connected to the computer 60 by a wired or wireless link.

[0093] For example, the computer 60 can comprise at least one processor 61 and at least one memory 62, at least one integrated circuit, at least one programmable system or at least one logic circuit, these examples not limiting the scope to be conferred to the term "computer". The term "processor" can be equivalent to a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP), a microcontroller, etc.

[0094] The computer 60 can be connected to a controller 600. The controller 600 sends at least one control signal to the computer 60. The computer 60 can be configured to send command signals to the one or more motors 30 in order to deliver the received commands. The computer 60 can also be configured to switch on or off the power lines that supply power to the one or more motors 30. The computer 60 is for example configured to control the one or more motors 30 in a normal operating mode of operation MODA and to disable the one or more electric motors 30 in a non-operating mode of the normal operating mode MODIA. The computer 60 can also store various configurations, each providing at least one operating command as a function of the control commands sent by the controller 600.

[0095] According to another feature, the servo controller 10 can comprise one or more actuator operation sensors 70 cooperating with the power rod 21, the actuator shaft or the electric motor 31.

[0096] For example, the actuator operation sensor 70 comprises a rotation sensor of the electric motor 31, for example an optical sensor or a sensor referred to by the acronym "RVDT", "RVDT" standing for "Rotary Variable Differential Transformer".

[0097] For example, this actuator operation sensor 70 is a linear sensor, possibly a Hall effect sensor or a sensor referred to by the acronym "LVDT", "LVDT" standing for "Linear Variable Differential Transformer". The actuator operation sensor 70 can comprise a processor unit 72 and a measuring rod 71 able to move with respect to the processor unit 72. The processor unit 72 can be fastened to the body 15 of the servo controller 10, for example to the actuator body 22. The measuring rod 71 can be fixed to the power rod 21.

[0098] Accordingly, each actuator operating sensor 70 is connected via a wired or wireless link to the computer 60 in order to send it an actuator operating signal. The actuator operating signal carries information related to the position of the power rod 21 along the longitudinal axis relative to the body 15 of the servo controller 10, and thus to the translational movement, or to the position of the rotating part 31 of the actuator shaft or electric motor.

[0099] According to another feature, the electric actuator 20 can comprise at least one actuator brake 55 for braking the power rod 21 or the actuator shaft 27 relative to the body 15 of the servo controller 10. The figures show a single actuator brake, but several actuator brakes can be arranged for safety reasons.

[0100] For example, the actuator brake 55 comprises a pad 551 able to move in translation, for example along the longitudinal axis, relative to a shoulder 270 of the actuator shaft 27, and an electromagnet 552 fixed to the actuator body controlled by the computer 60. The pad 551 is pressed against the shoulder 270 of the actuator shaft 27 by a spring 553 when the electromagnet 552 is no longer powered. For example, the computer 60 controls a contactor that powers the electromagnet 552.

[0101] Irrespective of the nature of the electric actuator 20 of the servo controller 10, the servo controller 10 comprises an anchoring portion 40 fixed to the electric actuator 20.

[0102] The anchoring portion 40 comprises an anchoring rod 42 able to move in translation relative to the body 15 of the servo controller 10 when no braking is performed. The anchoring rod 42 can comprise a fastener 420 that is articulated to a support when the electric actuator 20 is articulated to an object to be moved, or that is articulated to the object when the electric actuator 20 is articulated to the support.

[0103] In order to immobilize the anchoring rod 21 relative to the body 15 of the servo controller 10, the anchoring portion 40 comprises at least one anchoring brake 50 controlled by the computer 60. The figures show a single anchoring brake, but several anchoring brakes can be arranged for safety reasons. The anchoring brake 50 is configured so that, under the command of the computer 60, it immobilizes the anchoring rod 42 relative to the electric actuator 20 in a normal mode of operation MODA, MODIA of the servo controller 10, or allows the electric actuator 20 to move relative to the anchoring rod 42 in a safety mode of operation MODS.

[0104] For example, the anchoring brake 50 is an electromechanical brake, and the computer 60 controls a contactor that powers the anchoring brake 50.

[0105] Figure 1 An anchoring brake 50 in a rotary device is shown.

[0106] Thus, the anchoring portion 40 can comprise an anchoring shaft 43 rotatable with respect to a support member 45 fixed to the electric actuator 20.

[0107] For example, the support member 45 comprises an anchoring body 41 forming part of the main body 15 of the servo-controller 10. The anchoring body 41 and the actuator body 22 can form one and the same part, which can for example be cylindrical. A ball bearing 450 or the like can be inserted between the anchoring body 41 and the anchoring shaft 43, for example between a shoulder 410 of the anchoring body 41 and the anchoring shaft 43.

[0108] The anchoring portion 40 can comprise an anchoring translator 44 connected to the anchoring shaft 43 and to the anchoring rod 42. Thus, a translational movement of the anchoring shaft 43 along the longitudinal axis with respect to the anchoring rod 42 results in a rotational movement of this anchoring shaft 43 about the longitudinal axis with respect to the anchoring rod 42. For example, the anchoring translator 44 can comprise a ball screw or equivalent carried by the anchoring shaft. To this end, the anchoring shaft 43 can comprise threads cooperating with the anchoring translator 44 carried by the anchoring rod 42. The anchoring translator 44 can comprise a ball screw or equivalent, a nut, and even a reduction system.

[0109] The anchoring shaft 43 can extend entirely into the anchoring body 41, the anchoring rod 42 being able to extend partially into the anchoring body 41. Alternatively, the anchoring shaft 43 can extend partially into the anchoring body 41.

[0110] For example, the anchoring brake 50 comprises a pad 52 able to move translationally along the longitudinal axis with respect to a shoulder 430 of the anchoring shaft 43, and an electromagnet 51 controlled by the computer 60 and carried by the anchoring body 41. A spring 53 can extend between the pad 52 and the shoulder 410 of the anchoring body so as to urge the pad 52 away from the anchoring shaft 43. When the computer 60 controls the supply of power to the electromagnet, the pad 52 is pressed against the shoulder 430 of the anchoring shaft 43. For example, the computer 60 controls a contactor supplying power to the anchoring brake 50.

[0111] Thus, the anchoring brake 50 immobilizes the anchoring shaft 43 with respect to the anchoring rod 42 and the electric actuator 20 in the normal mode of operation MODA, MODIA, and releases the anchoring shaft 43 in the safe mode of operation MODS.

[0112] Figure 2 Another embodiment is shown, in which the anchoring portion 40 comprises an anchoring shaft 43 fixed to the electric actuator 20 and able to move translationally along the longitudinal axis with respect to the anchoring rod 42. Thus, the anchoring brake 50 connects the anchoring shaft 43 and the anchoring rod 42 in the normal mode of operation MODA, MODIA, and disconnects the anchoring shaft 43 and the anchoring rod 42 in the safe mode of operation MODS.

[0113] For example, the anchoring brake 50 comprises a finger 54 which projects into the hole of the anchoring shaft 4 and into the hole of the anchoring rod 42. The anchoring brake 50 can also comprise an actuating device 55 which is controlled by the computer 60 and which is able to move the finger 54 out of the hole of the anchoring rod 42.

[0114] In any variant and with reference to Figure 1 , the servo-controller 10 can comprise at least one anchoring portion operation sensor 73 cooperating with the anchoring rod 42 and / or with the anchoring shaft 43.

[0115] For example, the anchoring portion operation sensor 73 is a rotary sensor which measures the position of the anchoring shaft.

[0116] For example, the anchoring portion operation sensor 73 is a linear sensor. The anchoring portion operation sensor 73 can comprise a measuring unit 75 and a measuring rod 74 which is able to move translationally with respect to the measuring unit 75 along a longitudinal axis. The measuring unit 75 can be fastened to the main body 15 of the servo-controller 10, for example to the actuator main body 22 according to Figure 1 or to the anchoring shaft 43 according to Figure 2 . The measuring rod 74 can be fixed to the anchoring rod 42.

[0117] The anchoring portion operation sensor 73 is therefore connected to the computer 60 via a wired or wireless link, in order to send to it an actuator operation signal with information relating to the position of the anchoring rod 42 with respect to the main body 15 of the servo-controller 10 and therefore to the movement of the anchoring rod 42.

[0118] Figure 3 A vehicle is shown which has at least one servo-controller 10 according to the application.

[0119] In particular, the vehicle is a rotorcraft 95 which has a rotor 90 comprising a plurality of blades 91 carried by a hub 92. The rotor 90 can be rotated about an axis of rotation AX by means of a rotor main shaft 93 connected to the hub 92, which is moved by a power device, not shown here for simplicity. In order to vary the pitch of the blades 91, the rotorcraft 95 comprises a swashplate system 80.

[0120] The system 80 comprises a fixed swashplate 81 connected to each blade 91 by means of a mechanism 85. For example, the fixed swashplate 81 is arranged on a spherical joint 82 which is able to move translationally along the axis of rotation AX on a guide tube 83. The fixed swashplate 81 can therefore move translationally along the axis of rotation AX together with the spherical joint 82 and can perform two rotations about two axes AX1, AX2 which are orthogonal to the axis of rotation AX.

[0121] The fixed swashplate 81 can be a swashplate that does not rotate about the rotation axis AX. To this end, the fixed swashplate 81 can be hinged to a fixed scissor device 101 that is fastened to the guide tube 83 or to a support 84 that can be fixed to the guide tube 83.

[0122] The mechanism 85 can comprise a rotating swashplate 86 that has only one rotational degree of freedom with respect to the fixed swashplate 81. For example, the rotating swashplate 86 is carried by the fixed swashplate 81, a bearing system 88 being interposed between the rotating swashplate 86 and the fixed swashplate 81. For example, the rotating swashplate 86 can be hinged to a driving scissor device 102 that is hinged to the rotor mast 93 or to the hub 92. The system 80 further comprises one collective pitch link 87 per blade 91, each collective pitch link 87 being hinged to the blade 91 and to the rotating swashplate 86.

[0123] The swashplate system 80 is equipped with at least four electromechanical servo controllers 10, for example with only four servo controllers 11 to 14.

[0124] Reference 10 denotes any servo controller, references 11 to 14 denote specific servo controllers.

[0125] Each servo controller 10 is then hinged to the fixed swashplate 81 and to the support 84 respectively by the electric actuator 20 and the anchor 40, or by the anchor 40 and the electric actuator 20 respectively according to one example, which is not shown here in order not to overburden the number of figures. The servo controllers 10 are controlled by the same computer 60. Figure 3

[0126] The rotorcraft 95 can comprise at least one controller 600 that sends control signals to the computer 60 to extend or retract at least one of the servo controllers 11 to 14.

[0127] For example, such a controller 600 can comprise an autopilot 65 or an interface that can be operated by a human pilot.

[0128] Such an interface can comprise a joystick 66 that can be rotated about a single axis to control the overall variation of the pitch of the blades 91. Thus, the interface sensor 67 can send control signals with the position of the joystick 66 to the computer 60. For example, the interface sensor 67 can comprise a potentiometer.

[0129] For example, the term "signal" can equally denote a digital signal, an analog signal, an electrical signal or an optical signal.

[0130] ​For example, such an interface can comprise a handle 63 which can be rotated about two axes in order to control the periodic variation of the pitch of the paddle 91. The interface sensor means 64 can thus send control signals to the computer 60 with the position of the handle 63. For example, the interface sensor means 64 can comprise two potentiometers.

[0131] According to another aspect, if necessary, the computer 60 can communicate with an alarm 68 to produce a visual, audible or tactile alarm.

[0132] Moreover, each servo-controller 10 can be in a normal operating mode of operation mode MODA or inoperative mode MODIA or in a safe operating mode MODS. The system 80 can thus be in various configurations depending on the current operating mode of each servo-controller 10. Each configuration is associated with a particular operating mode of each servo-controller 10. For example, one configuration corresponds to the state in which all the servo-controllers 11 to 14 are in the operating mode MODA, another configuration corresponds to the state in which the first servo-controller 11 is in the inoperative mode MODIA and the other servo-controllers 12 to 14 are in the operating mode MODA, another configuration corresponds to the state in which the first servo-controller 11 is in the safe operating mode MODS and the other servo-controllers 12 to 14 are in the operating mode MODA, etc. The computer 60 thus stores one control model for each possible configuration, each control model indicating how to control each servo-controller 10 as a function of the control signals received.

[0133] For example, each model can comprise one or more equations, matrices, etc. which determine in a conventional manner the command signals to be sent to the servo-controllers 10 as a function of the control signals received.

[0134] Figure 4 to Figure 6 An example of the operation of a system according to the application is illustrated.

[0135] With reference to Figure 4 , at least three servo-controllers 12, 13, 14 are in the normal operating mode of operation mode MODA. The anchoring rods of these three servo-controllers 12, 13, 14 are stationary with respect to the corresponding electric actuators 20. The computer 60 applies the first model and sends command signals to at least one electric motor 30 of these three servo-controllers 12, 13, 14 to extend, retract or maintain them at a given length as a function of the signals sent by one of the interfaces or autopilots.

[0136] Optionally, all servo controllers 11 to 14 are in the active mode of operation MODA, or at least one servo controller 11 to 14 is in the inactive mode of operation MODA of the normal operation mode. According to the example shown, the servo controller 11 is in this inactive mode MODIA, the power rod 21 of which servo controller 11 can be moved freely in translation along the longitudinal axis with respect to the main body 15 of the servo controller 11. To this end, one or more rotating parts of the one or more electric motors are made freely rotatable with respect to one or more stators.

[0137] With reference to Figure 5 , the electric motor 30 of one of the servo controllers 11 to 14 in the active mode of operation can fail, according to the example shown the servo controller 12 has failed. The computer 60 can easily detect this failure. If the actuator operation sensor 70 of this servo controller 12 sends a measurement signal to the computer 60 indicating that the actuator operation sensor 70 is retracted or extended in a manner not corresponding to a given command, the computer 60 can deduce therefrom that there is a failure. This failure can be caused, for example, by a mechanical jam or a failure of the electric motor 30.

[0138] The computer 60 can send an alarm signal to the alarm 68 to generate a failure alarm.

[0139] In the absence of a mechanical jam of the electric actuator 20, the power rod 21 of the servo controller 12 is able to move with respect to the one or more electric motors 30 of this servo controller 12. In this case, the actuator converter 26 allows the power rod 21 to move in translation along the longitudinal axis with respect to the actuator shaft 27.

[0140] The computer 60 can then switch the failed servo controller 12 to the inactive mode of operation MODIA of the normal operation mode, for example by opening the contactors supplying power to the one or more electric motors 30 of this servo controller 12. In addition, the computer 60 changes the operating model and controls the servo controller 11, which is switched from the inactive mode MODIA to the active mode MODA.

[0141] With reference to Figure 6 If the computer 60 detects a jam of the servo controller 12, the computer 60 controls the anchoring brake of this servo controller 12 to disengage the electric actuator 20 from the anchoring rod 42. If the actuator operation sensor 70 sends a measurement signal to the computer 60 indicating that the actuator operation sensor 70 is not retracted or extended, while the computer 60 is controlling the other servo controllers 11, 13, 14 to move the stationary cam plate 81, the computer 60 can deduce therefrom that the servo controller is jammed.

[0142] The seized servo controller 12 then follows the movement of the fixed swash plate 81 and flight can continue normally.

[0143] The computer 60 can send an alert signal to the alarm 68 to generate a seizure alert.

[0144] Naturally, the application is susceptible to many variations in its implementation. While several embodiments have been described above, it should be understood that they have been given by way of example only. Numerous changes in the arrangements of parts can be made by those skilled in the art and which are encompassed within the spirit of the application as broadly disclosed. While the above description has focused on the use of the application in the context of a helicopter, it will be appreciated that the application is equally applicable to other types of aircraft.

Claims

1. A linear electromechanical servo controller (10) comprising a power rod (21) capable of translational movement, The linear electromechanical servo controller (10) includes a single linear electric actuator (20) having at least one electric motor (30) connected to the power rod (21) via a mechanical link (25). The linear electromechanical servo controller (10) includes an anchor portion (40) fixed to the linear electric actuator (20). The at least one electric motor (30) is controlled by a computer (60). The anchor portion (40) has a function relative to the linear electromechanical servo controller. 10) The main body (15) of the anchor rod (42) is translatably movable, the anchor part (40) having at least one anchor actuator (50) configured to, upon request from the computer (60), fix the anchor rod (42) relative to the linear electromechanical actuator (20) in normal operation mode, and make the linear electromechanical servo controller transparent in safe operation mode (MODS) by allowing the linear electromechanical actuator (20) to move relative to the anchor rod (42), wherein, The transparency refers to the fact that the linear electromechanical servo controller also allows the controlled object to move freely.

2. The linear electromechanical servo controller according to claim 1, in, The linear electric actuator (20) includes a plurality of electric motors (30) that cooperate with the same actuator shaft (27) as the mechanical link (25).

3. The linear electromechanical servo controller according to claim 1, in, The mechanical link (25) includes an actuator shaft (27) fixed to a rotating portion (31) of the at least one electric motor (30), and the mechanical link (25) includes an actuator converter (26) connected to the actuator shaft (27) and the power rod (21), the actuator converter (26) being configured to convert rotational motion of the actuator shaft (27) into translational motion of the power rod (21) and vice versa.

4. The linear electromechanical servo controller according to claim 3, in, The actuator shaft (27) includes a thread (28) that mates with the actuator converter (26).

5. The linear electromechanical servo controller according to claim 1, in, The anchor portion (40) includes an anchoring shaft (43) rotatable relative to a support member (45) fixed to the linear actuator (20). The anchor portion (40) includes a reversible anchoring converter (44) connected to the anchoring shaft (43) and the anchoring rod (42) and configured such that translational movement of the anchoring shaft (43) relative to the anchoring rod (42) causes rotational movement of the anchoring shaft (43), and vice versa. The anchoring actuator (50) is configured to fix the anchoring shaft (43) relative to the anchoring rod in the normal operation mode and release the anchoring shaft (43) in the safe operation mode (MODS).

6. The linear electromechanical servo controller according to claim 1, in, The anchor portion (40) includes an anchor shaft (43) fixed to the linear electric actuator (20) and capable of translational movement relative to the anchor rod (42). The anchor actuator (50) is configured to connect the anchor shaft (43) and the anchor rod (42) in the normal operation mode and to disengage the anchor shaft (43) and the anchor rod (42) in the safe operation mode (MODS).

7. The linear electromechanical servo controller according to claim 1, in, The linear electric actuator (20) includes an actuator brake (55) that cooperates with the power rod (21) or an actuator shaft (27) that is connected to the power rod (21) via an actuator converter (26).

8. The linear electromechanical servo controller according to claim 1, in, The computer (60) is configured to control the at least one electric motor (30) in the working mode (MODA) of the normal operation mode and to suppress the at least one electric motor (30) in the non-working mode (MODIA) of the normal operation mode.

9. The linear electromechanical servo controller according to claim 1, in, The linear electromechanical servo controller (10) is capable of operating in a variety of configurations, the configuration depending on the current operating mode of the linear electromechanical servo controller (10), the current operating mode being a mode corresponding to the normal operating mode or the safe operating mode (MODS), and the computer (60) including a control model for each configuration to control the linear electromechanical servo controller (10) according to at least one received control signal.

10. The linear electromechanical servo controller according to claim 1, in, The linear electromechanical servo controller (10) includes at least one actuator operation sensor (70) that sends an actuator operation signal to the computer (60) containing information related to the motion of the power rod (21) relative to the body (15) of the linear electromechanical servo controller (10).

11. The linear electromechanical servo controller according to claim 1, in, The linear electromechanical servo controller (10) includes at least one anchor part operation sensor (73), which sends an anchor part operation signal to the computer (60) containing information related to the movement of the anchor rod (42) relative to the body (15) of the linear electromechanical servo controller (10).

12. A swashplate system (80) having at least four linear electromechanical servo controllers (10), each of which is hinged to a support (84) and a fixed swashplate (81) to control the pitch of the blades (91) of a rotor (90). in, Each linear electromechanical servo controller (10) is a linear electromechanical servo controller according to claim 1, wherein the electric motor (30) of the linear electromechanical servo controller (10) is controlled by a common computer (60), and the anchor portion (40) of each linear electromechanical servo controller (10) has an anchor rod (42) hinged to the support (84) or the fixed swashplate (81).

13. The swashplate system according to claim 12, in, The swashplate system (80) can operate in a variety of configurations depending on the current operating mode of each linear electromechanical servo controller (10), which can be a normal operating mode or a mode in a safe operating mode (MODS). The computer (60) includes a control model for each configuration to control the linear electromechanical servo controller (10) according to at least one received control signal.

14. The swashplate system according to claim 12, in, The swashplate system (80) consists of only four linear electromechanical servo controllers (10).

15. A rotorcraft (95) having a rotor (90) comprising a plurality of blades (91), the rotorcraft (95) including a swashplate system (80) having at least four linear electromechanical servo controllers (10) hinged to a fixed swashplate (81), the fixed swashplate (81) being connected to each blade (91) via a mechanism (85). The swashplate system (80) described therein is the swashplate system according to claim 12.

Images