Dual Independent Hybrid Actuator System

Abstract

A dual independent hybrid actuator system includes an actuator body defining a hydraulic chamber. The actuator system includes a hydraulic piston assembly that includes a hydraulic piston disposed within the hydraulic chamber and dividing the hydraulic chamber into a first sub-hydraulic chamber fluidly connected to a first hydraulic fluid passage and a second sub-hydraulic chamber fluidly connected to a second hydraulic fluid passage. The actuator system further includes a piston rod mounted to the hydraulic piston, the piston rod passing through the second sub-hydraulic chamber, wherein a distal end extends outwardly from the actuator body. The actuator system further includes an electric motor mounted to the actuator body and a threaded shaft mechanically coupled to the motor shaft of the electric motor. The threaded shaft passes through the first sub-hydraulic chamber and engages a threaded port formed in the hydraulic piston assembly.

Description

Technical Field

[0001] The invention of the present disclosure generally relates to an actuator that can be independently operated by a hydraulic system and an electric motor. Background Art

[0002] Aircraft utilize flight control surfaces, such as flaps and rudders, manipulated by actuators to change the orientation and / or position of the flight control surfaces relative to the fuselage. Hydraulic actuators commonly used in commercial aircraft are controlled by an electro-hydraulic servo valve of a hydraulic system in communication with the hydraulic actuator. Other types of mechanical systems besides aircraft also utilize hydraulic actuators to manipulate mechanical components. In some cases, a backup system can be used in combination with the hydraulic actuator to enable the flight control surface or other mechanical components to be manipulated by the backup system in the event that the hydraulic system cannot provide sufficient control. Summary of the Invention

[0003] According to one example of the present disclosure, a dual independent hybrid actuator system includes an actuator body that defines a hydraulic chamber within the interior of the actuator body. The actuator body also defines a first hydraulic fluid passage and a second hydraulic fluid passage that are in fluid communication with the hydraulic chamber. The actuator system includes a hydraulic piston assembly that includes a hydraulic piston disposed within the hydraulic chamber and dividing the hydraulic chamber into a first sub-hydraulic chamber in fluid communication with the first hydraulic fluid passage and a second sub-hydraulic chamber in fluid communication with the second hydraulic fluid passage. The actuator system also includes a piston rod mounted to the hydraulic piston, the piston rod passing through the second sub-hydraulic chamber, wherein a distal end extends outward from the actuator body. The actuator system also includes an electric motor mounted to the actuator body and a threaded shaft mechanically coupled to the motor shaft of the electric motor. The threaded shaft passes through the first sub-hydraulic chamber and engages a threaded port formed in the hydraulic piston assembly.

[0004] According to another example of the present disclosure, a method of controlling a dual independent hybrid actuator system includes controlling the operation of an electro-hydraulic servo valve of a hydraulic system to create a first hydraulic differential between opposite sides of a hydraulic piston that pushes a piston rod mounted to the hydraulic piston to move in a first translation direction. The method further includes, during the piston rod moving in the first translation direction, controlling the operation of an electric motor having a motor shaft mechanically coupled to the hydraulic piston via a threaded shaft. Controlling the operation of the electric motor includes supplying power to the electric motor to cause the motor shaft to rotate in a first rotational direction that pushes the piston rod to move in the first translation direction in coordination with the force applied by the first hydraulic differential, or reducing the resistance of the electric motor to the movement of the piston rod in the first translation direction.

[0005] According to another example of the present disclosure, a method of controlling a dual independent hybrid actuator system includes, during a first control operation, controlling the operation of an electrohydraulic servo valve of a hydraulic system to create a first hydraulic differential between opposite sides of a hydraulic piston, which pushes a piston rod mounted to the hydraulic piston to move in a first translational direction; and during a second control operation, controlling the operation of an electric motor having a motor shaft that is mechanically coupled to the hydraulic piston via a threaded shaft to rotate the motor shaft in a first rotational direction, which pushes the piston rod to move in the first translational direction.

[0006] The features and techniques discussed in this summary of the invention may be provided independently in various examples, or may be combined in other examples, and further details thereof are described with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 An example of a dual independent hybrid actuator system according to the present disclosure is shown.

[0008] Figure 2A and Figure 2B An example electric brake that can be used with the Figure 1 actuator system is shown.

[0009] Figure 3A A detailed view of the Figure 1 actuator system is shown, including an example interface between a threaded shaft and a threaded port.

[0010] Figure 3B A detailed view of the Figure 1 actuator system is shown, including an example in-line check valve.

[0011] Figure 4 is a flowchart showing an example method of a dual independent hybrid actuator system for controlling an actuator system including Figure 1 the

[0012] Figure 5 Schematically shows an example control architecture of a dual independent hybrid actuator system for an actuator system including Figure 1 the

[0013] Figure 6 An example planetary gear system that may be included in the driveline of an actuator system including Figure 1 the

[0014] Figure 7 Shows an example computing system that can implement the Figure 4 method and incorporates the Figure 5 control architecture of a dual independent hybrid actuator system for an actuator system including Figure 1 the Detailed Implementation Modes

[0015] Disclosed herein is a dual independent hybrid actuator system and an operating method thereof, which enable independent control of a mechanical component, such as a flight control surface, by a hydraulic force provided by a hydraulic system and a mechanical force provided by an electric motor. In the disclosed example, the actuator system incorporates an electric motor into an actuator body and mechanically couples the electric motor to a hydraulic piston assembly via a threaded shaft. The hydraulic piston assembly can be manipulated independently by the electric motor via the threaded shaft and / or by a hydraulic system that provides a hydraulic differential to opposite sides of the hydraulic piston. In one example, an electro-hydraulic servo valve (also known as an electro-hydraulic servo actuator (EHSA)) of the hydraulic system can be used for primary control of the actuator position, and an electric motor mechanically coupled to the hydraulic piston assembly can be used for alternative or additional control of the actuator position.

[0016] Figure 1 An example of a dual independent hybrid actuator system 100 is shown. Actuator system 100 includes an actuator body 110 that defines a hydraulic chamber 112 within the interior of the actuator body. In Figure 1 , aspects of actuator system 100 are shown in a cross-sectional view to illustrate internal components contained within actuator body 100. Actuator body 110 also defines a first hydraulic fluid passage 114 and a second hydraulic fluid passage 116 that are in fluid communication with different regions of hydraulic chamber 112.

[0017] Actuator system 100 also includes a hydraulic piston assembly 118 that includes a hydraulic piston 120 disposed within hydraulic chamber 112. Hydraulic piston 120 divides hydraulic chamber 112 into a first sub-hydraulic chamber 112A that is in fluid communication with first hydraulic fluid passage 114 and a second sub-hydraulic chamber 112B that is in fluid communication with second hydraulic fluid passage 116. Hydraulic piston 120 may include one or more seals and / or bearings, schematically indicated as 121 and 123, that engage the inner surface of hydraulic chamber 112 to seal first sub-hydraulic chamber 112A from second sub-hydraulic chamber 112B and / or reduce friction against the movement of the hydraulic piston relative to the actuator body.

[0018] Hydraulic piston assembly 118 also includes a piston rod 122 that is mounted to hydraulic piston 120. Piston rod 122 passes through second sub-hydraulic chamber 112B through an opening 111 formed in actuator body 110 and has a distal end 124 that extends outward from the actuator body. Actuator body 110 may include one or more seals and / or bearings, schematically indicated as 113, that are connected to piston rod 122 to seal second sub-hydraulic chamber 112B and / or reduce friction against the movement of the piston rod.

[0019] The actuator body 110 and the piston rod 122 are coupled to form a linkage 126 that includes a first bearing attachment point 128 at the distal end 124 of the piston rod 122 and a second bearing attachment point 130 at the other distal end 132 of the actuator body that is opposite the first bearing attachment point 128. As used herein, the term "actuator position" may refer to the length of the linkage 126 formed between the first bearing attachment point 128 of the piston rod 122 and the second bearing attachment point 130 of the actuator body. In one example, the first bearing attachment point 128 may be mechanically coupled to Figure 1 the controlled mechanical component 127 (e.g., a flight control surface) schematically shown in, the controlled mechanical component 127 may include or be associated with a position sensor 129, and the electronic control system 170 may measure and determine the position and / or orientation of the mechanical component 127 via the position sensor such that the electronic control system is able to move the hydraulic piston assembly 118 to achieve the target position and / or orientation of the mechanical component 127.

[0020] The actuator system 100 includes a hydraulic system 134 that is in communication with a first hydraulic fluid passage 114 and a second hydraulic fluid passage 116 of the actuator body 110. The hydraulic system 134 is schematically shown in Figure 1 as including one or more hydraulic pumps 136 and one or more electro-hydraulic servo valves 138. The one or more hydraulic pumps 136 may be selectively operated by the electronic control system 170 to generate hydraulic pressure within the hydraulic system 134, and the one or more servo valves 138 may be selectively operated by the electronic control system to independently control the supply of hydraulic fluid to the first sub-hydraulic chamber 112A via the first hydraulic fluid passage 114 and the supply of hydraulic fluid to the second sub-hydraulic chamber 112B via the second hydraulic fluid passage 116, thereby creating a target pressure differential between the first and second sub-hydraulic chambers. However, in at least some examples, one or more bi-directional hydraulic pumps (e.g., of pump 136) or hydraulic motors of the hydraulic system 134 may be used to control the hydraulic differential between the first sub-hydraulic chamber 112A and the second sub-hydraulic chamber 112B.

[0021] According to the operation of an example of the actuator system 100, a first pressure difference can be generated between the first sub-hydraulic chamber 112A and the second sub-hydraulic chamber 112B, where the first sub-hydraulic chamber has a higher hydraulic pressure than the second sub-hydraulic chamber, to push the hydraulic piston 120 and the piston rod 122 of the hydraulic piston assembly 118 along the translation axis 125 in the first translation direction 102 (i.e., the extending direction), thereby increasing the length of the link 126 between the bearing attachment points 128 and 130. A second pressure difference between the first sub-hydraulic chamber 112A and the second sub-hydraulic chamber 112B can be generated by the hydraulic system 134, where the second sub-hydraulic chamber has a higher hydraulic pressure than the first sub-hydraulic chamber, to push the hydraulic piston 120 and the piston rod 122 of the hydraulic piston assembly 118 along the translation axis 125 in the second translation direction 104 (i.e., the retracting direction) opposite to the first translation direction 102, thereby reducing the length of the link 126 between the attachment points 128 and 130.

[0022] The actuator system 100 further includes an electric motor 140 mounted to the actuator body 110. In Figure 1 the illustrated example, the electric motor 140 is housed in a separate sub-chamber of the actuator body 110, which is partially defined by the cover portion 110A. The electric motor 140 includes an electric motor shaft 142 that rotates about an axis (e.g., 125) when power is applied by the electronic control system 170. According to one embodiment, the electric motor 140 can be in the form of a DC motor or an AC motor. The electronic control system 170 can selectively change the power and / or phase supplied to the electric motor 140 to control the rotation direction and rotation rate of the electric motor shaft 142.

[0023] The electric motor shaft 142 can be mounted on one or more axial bearings, examples of which are schematically shown as 145A and 145B. The axial bearings can be provided relative to the electric motor shaft 142 in other suitable amounts and / or positions. The axial bearings 145A and 145B can be in the form of thrust bearings that support the load of the electric motor shaft in the axial direction or the lateral direction (e.g., along the axis 125).

[0024] The actuator system 100 further includes a threaded shaft 150 mechanically coupled to the electric motor shaft 142 of the electric motor 140. In Figure 1 the illustrated example, the threaded shaft 150 passes through the first sub-hydraulic chamber 112A and engages a threaded port 152 formed in the hydraulic piston assembly 118. As an example, the hydraulic piston assembly 118 includes a ball screw nut (shown as 310 in Figure 3A ) that defines the threaded port 152, and the threaded shaft 150 forms a ball screw shaft (shown as 312 in Figure 3A ).

[0025] In at least some instances, the hydraulic piston assembly 118 defines an internal chamber 154 within the hydraulic piston 120 and / or the piston rod 122 that houses a portion of the threaded shaft 150 extending through the threaded port 152. In Figure 1 the illustrated instance, the threaded shaft 150 is coaxial with the piston rod 122 and the translational axis 125 of the piston rod. However, in other instances, the threaded shaft 150 may be parallel to either the piston rod 122 or the translational axis 125, but not coaxial therewith. Also in Figure 1 the illustrated instance, the motor shaft 142 is coaxial with the piston rod 122 and the translational axis 125 of the piston rod. However, in other instances, the motor shaft 142 may be oriented at an angle relative to the piston rod 112 and the translational axis 125, or the motor shaft 142 may be parallel to either the piston rod 122 or the translational axis 125, but not coaxial therewith. For example, the motor shaft 142 may be mechanically coupled to the threaded shaft 150 via a drivetrain that enables the motor shaft 142 to be offset and / or angled relative to the threaded shaft 150.

[0026] The actuator system 100 may include a drivetrain 160 through which the threaded shaft 150 is mechanically coupled to the motor shaft 142 of the motor 140. In at least some instances, the drivetrain 160 provides a non-uniform (e.g., greater than or less than 1:1) effective gear ratio between the motor shaft 142 and the threaded shaft 150. As an example, the non-uniform effective gear ratio of the drivetrain 160 provides a reduced rotational rate of the threaded shaft 150 relative to the rotational rate of the motor shaft 142, thereby providing a mechanical advantage to the motor 140 that increases the motor torque provided to the threaded shaft 150 and the piston assembly 118. In Figure 6 the illustrated instance, the drivetrain 160 includes a planetary gear system. However, other suitable drivetrains may be used. Figure 1 The drivetrain 160 is also shown to include an output shaft 162 and an axial bearing 164 through which the threaded shaft 150 is mounted or otherwise mechanically coupled to the threaded shaft 150. The axial bearing 164 may be in the form of a thrust bearing that supports the load of the output shaft 162 in the axial direction or the lateral direction (e.g., along the axis 125).

[0027] In at least some instances, the electric motor 140 may take the form of a stepper motor, which enables the electronic control system 170 to measure and determine the rotational position and rotational rate of the motor shaft 142. Additionally or alternatively, one or more position sensors 148A, 148B, etc. may be included, which enable the electronic control system 170 to measure and determine the rotational position and rotational rate of the motor shaft 142. The position sensors may include resolvers mounted on the motor shaft 142, output shaft 162, and / or threaded shaft 150 to measure the rotation of the motor shaft 142 and / or threaded shaft 150. As an example, the position sensors may also include encoders and Hall effect sensors to determine the rotational position of the shaft. In at least some instances, the position sensors may be used to detect backlash between the threaded shaft 150 and the hydraulic piston 120. The position sensors may be disposed in other suitable amounts and / or positions relative to the motor shaft 142, output shaft 162, and / or threaded shaft 150. In at least some instances, the actuator position may be determined by the electronic control system 170 based on sensor data received from the position sensors 148A and 148B, or by the motor 140 in the case of a stepper motor that reports its rotational position.

[0028] According to an example operation of the actuator system 100, rotation of the motor shaft 142 of the electric motor 140 in a first rotational direction (e.g., 144 or 146) pushes the hydraulic piston 120 and piston rod 122 of the hydraulic piston assembly 118 to move in a first translational direction 102, causing the distal end 124 of the piston rod 122 to extend outward from the actuator body 110, thereby increasing the length of the link 126 between the attachment points 128 and 130. Rotation of the motor shaft 142 of the electric motor 140 in a second rotational direction opposite the first rotational direction pushes the hydraulic piston 120 and piston rod 122 of the hydraulic piston assembly 118 to move in a second translational direction 104 opposite the first translational direction 102, causing the distal end 124 of the piston rod 122 to retract inwardly toward the actuator body 110, thereby decreasing the length of the link 126 between the attachment points 128 and 130.

[0029] During at least some operating conditions, control system 170 may coordinate the operation of electric motor 140 and the operation of one or more electro-hydraulic servo valves 138 of hydraulic system 134. For example, control system 170 may increase the hydraulic pressure in first sub-hydraulic chamber 112A relative to second sub-hydraulic chamber 112B to achieve a first pressure differential that pushes piston rod 122 in a first translation direction 102, while operating electric motor 140 to rotate in a first rotational direction, thereby increasing the length of link 126 between attachment points 128 and 130 through the coordinated operation of both hydraulic system 134 and electric motor 140. During other operating conditions, electronic control system 170 may increase the hydraulic pressure in second sub-hydraulic chamber 112B relative to first sub-hydraulic chamber 112A to achieve a second pressure differential, while operating electric motor 140 to rotate in a second rotational direction opposite the first rotational direction, thereby decreasing the length of link 126 between attachment points 128 and 130 through the coordinated operation of both hydraulic system 134 and electric motor 140. Additional examples of the coordinated operation between hydraulic system 134 and electric motor 140 will be described in further detail with reference to Figure 4 and Figure 5 Further detail.

[0030] The possibility of backdriving electric motor 140 and driveline 160 may exist under conditions of hydraulic and / or control loss in hydraulic system 134. Under these conditions, electric motor 140 in combination with threaded shaft 150 may be used as the primary control mode for hydraulic piston assembly 118. However, backdriving of electric motor 140 will occur if the force applied to the controlled mechanical component 127 (such as an aerodynamic load) is greater than the static force that resists the movement of hydraulic piston assembly 118. In at least some instances, electric motor 140, driveline 160, and / or threaded shaft 150 may be used in conjunction with one or more electric brakes 149A, 149B, etc. that may be electrically actuated by electronic control system 170. Electric brakes 149A and 149B may be selectively engaged by electronic control system 170 to prevent or inhibit the movement of hydraulic piston assembly 118 due to backdriving of the controlled mechanical component. The electric brakes may be disposed in other suitable amounts and / or positions relative to electric motor shaft 142, output shaft 162, and / or threaded shaft 150.

[0031] Figure 2A and Figure 2B Illustrates that can be used with Figure 1An example electric brake 200 for use with the actuator system 100, such as for electric brakes 149A and 149B. The electric brake 200 includes a housing 210 that can be mounted to the actuator body 110 of the actuator system 100; a coil 212 to which electrical energy is applied; a drive cup 214 mounted to a shaft that provides braking to the shaft, such as the motor shaft 142; a support plate 216; an armature 218; an end plate 220; a set of friction discs 222 mounted between the armature 218 and the end plate 220; and a spring 224 mounted between the armature 218 and the support plate 216. In one example, the electric brake 200 is an electrically released brake that engages when the coil 212 has no electrical energy. When electrical energy is not supplied to the coil 212, the spring 224 applies a force on the set of friction discs 222 as shown in Figure 2B to thereby apply a braking force to the rotation of the shaft and prevent torque in the shaft. In at least some examples, the brake does not disengage until electrical power is supplied to the coil. In this case, the coil generates a magnetic field that is used to pull the armature plate towards or against the spring, overcoming the spring force and allowing the friction discs to separate from each other. Thereby allowing the discs to rotate freely without being able to transfer or hold torque. Figure 2A An example of supplying electrical energy to the coil 222 is shown, which pulls the armature 218 (e.g., containing a magnet or magnetic attracting material, such as metal) towards the support plate 216 and removes the braking force applied to the shaft. It should be understood that the electric brake 200 is one example of an electric brake that can be used with the actuator system 100, and other electric brakes can be used, including electric brakes that apply a braking force to the shaft when electrical energy is applied to the brake.

[0032] Figure 3A is shown Figure 1 A detailed view of the actuator system 100 is shown, including an example interface between the threaded shaft 150 and the threaded port 152. In one example, the threaded port 152 is formed by a ball screw nut 310, and the threaded shaft 150 forms a ball screw shaft 312. In this example, the ball screw nut 310 defines an external thread race 314, and the ball screw shaft 312 defines an internal thread race 316. The thread races 314 and 316 together contain a ball bearing 318 that reduces rotational friction and supports the radial and axial loads between the ball screw nut 310 and the ball screw shaft 312.

[0033] In addition, in Figure 3AIn the illustrated example, the hydraulic piston assembly 118 defines a fluid passageway 320 between the internal chamber 154 and the first sub-hydraulic chamber 112A, which is independent of the opening 322 of the threaded port 152 through which the threaded shaft 150 passes. The fluid passageway 320 forms a drain port that allows hydraulic fluid leaking through the ball bearing 318 to be drained into the internal chamber 154. If the hydraulic fluid cannot be drained from the internal chamber 154, damage to the piston rod 122 and / or the hydraulic piston assembly 118 may occur. Thus, the fluid passageway 320 can reduce or prevent damage caused by the accumulation of hydraulic fluid in the internal chamber 154.

[0034] In Figure 3A it, the fluid passageway 320 is formed in the ball screw nut 310; however, the fluid passageway can alternatively or additionally be formed in the body of the hydraulic piston 120 and / or the piston rod 122. The hydraulic piston assembly 118 also includes a one-way in-line check valve 324 positioned along the fluid passageway 320, which provides a greater resistance to hydraulic fluid flowing along the fluid passage through the in-line check valve towards the internal chamber 154 compared to the hydraulic fluid flowing through the in-line check valve from the internal chamber towards the first sub-hydraulic chamber 112A. Thus, when the threaded shaft 150 rotates in the direction of increasing its protrusion into the internal chamber 154, the hydraulic fluid can be drained from the internal chamber 154 and flow back into the first sub-hydraulic chamber 112A via the fluid passageway 320 and the check valve 324.

[0035] Figure 3B A detailed view of the actuator system 100 is shown, including an example check valve 324 located between the internal chamber 154 and the first sub-hydraulic chamber 112A along the fluid passageway 320 of the hydraulic piston assembly 118. In this example, the check valve 324 includes a valve core 330 that is pushed against the valve seat 332 by a spring element 334 disposed between the valve core and the mounting bracket 336 or other features of the valve. Hydraulic fluid within the internal chamber 154 having sufficient pressure can overcome the spring force provided by the spring element 334, which causes the valve core 330 to shift from the valve seat 332, thereby allowing the hydraulic fluid to flow through the valve via the fluid passageway 320 into the first sub-hydraulic chamber 112A. It should be understood that other suitable types or configurations of one-way in-line check valves can also be used for the check valve 324.

[0036] Figure 4 is a flowchart of an example method 400 of a dual independent hybrid actuator system for controlling an actuator system 100 including Figure 1 As an example, the method 400 can be executed by an Figure 1 electronic control system 170.

[0037] In at least some instances, method 400 may include calibrating the actuator system at 410. As an example of calibration, the piston rod 122 may be extended and retracted over its operating range of motion, and sensor measurements may be captured and recorded by the electronic control system over the operating range of motion. For example, in the case where the motor 140 forms a stepper motor, the rotational positioning data obtained over the operating range of motion of the piston rod may be mapped by the electronic control system such that the electronic control system can later reference the mapped data to identify the current position (i.e., actuator position) of the piston rod at a given point in time. As another example, Figure 1 the position sensors 148A and 148B enable the electronic control system to measure and determine the amount of rotation of the motor shaft 142, which can be mapped to the operating range of motion of the piston rod. Similarly, this initial calibration enables the electronic control system to later reference the mapped data to identify the current position (i.e., actuator position) of the piston rod at a given point in time by observing the amount of rotation of the motor shaft 142 in either direction. At 410, calibration relative to other sensors may be performed over the operating range of the piston rod, including the sensor 129 that measures the position and / or orientation of the controlled mechanical component. The positioning data captured by the electronic control system from the sensor 129 may be mapped to the data captured by other sensors (including the position sensors 148A and 148B), as well as the stepper motor positioning data.

[0038] At 412, the method includes receiving input data, which may include inputs from sensors (e.g., 129, 148A, 148B, rotational position from the motor 140 in the case of a stepper motor, etc.), a position reference (position reference) representing a control input for a mechanical component (e.g., a flight control surface) to be controlled by the actuator system, and an indication of a selected operating mode (e.g., from an operator or a computing system).

[0039] At 414, the method includes identifying a target change in the state of the actuator system based on the input data received at 412. As an example, the target change in the state of the actuator system includes a target magnitude (e.g., distance) and a target translation direction (e.g., extend or retract), which represent the difference between the current actuator position and the target actuator position identified based on the input data received at 412. Identifying the target change in the state of the actuator system may further be based on the calibration data obtained at 410.

[0040] At 416, the method includes identifying an operating mode of a dual independent hybrid actuator system based on input data received at 412. As an example, the input data received at 412 can include a command identifying an operating mode selected by an operator or by a computing system (e.g., an on-board flight control computing system). As another example, the input data received at 412 can include data indicating a fault condition, an error condition, or a normal operating condition (fault-free operation).

[0041] In at least some instances, the dual independent hybrid actuator system can operate in a selected one of a plurality of operating modes, including an active / active (A / A) mode, an active / no-load (A / NL) mode, an active / passive (A / P) mode, or a passive / active (P / A) mode, where each is represented by the activity of the hydraulic system activity compared to the activity of the motor (i.e., hydraulic system activity / motor activity).

[0042] In the active / active mode, the hydraulic system and the motor are actively controlled to generate a combined force on a hydraulic piston assembly by the hydraulic force applied by the hydraulic system and the mechanical force applied by the motor. The active / active mode can be selected to balance the force contributions between the hydraulic system and the motor. For example, due to the contribution of the mechanical force of the motor, the hydraulic differential required to generate a given total force on the hydraulic piston can be reduced. The active / active mode can be used in situations where the hydraulic system cannot generate sufficient hydraulic pressure or where operation at a lower hydraulic differential is desired. The active / active mode can provide higher dynamics than the active / passive mode.

[0043] In the active / no-load mode, the hydraulic system and the motor are actively controlled, but the hydraulic piston assembly is operated by the hydraulic force applied by the hydraulic system while the motor is operated to reduce, minimize, or eliminate the mechanical force applied by the motor (and its drivetrain) to the hydraulic piston assembly, including friction and drag. The active / no-load mode can be used when the motor serves as a backup for the hydraulic system while also reducing or minimizing the hydraulic differential required to overcome the resistance from the motor (and its intermediate drivetrain). The active / no-load mode can provide higher dynamics than the active / passive mode. In at least some settings, compared to the active / active mode, the active / no-load mode consumes less power, reduces ball screw wear, and improves the efficiency of an electro-hydraulic servo actuator (EHSA).

[0044] In the active / passive mode, the hydraulic system is actively controlled to apply a hydraulic force on the hydraulic piston assembly, and the motor and its drivetrain passively follow the movement of the hydraulic piston assembly. The active / passive mode can be used when the motor serves as a backup for the hydraulic system while also avoiding the control overhead associated with the motor.

[0045] In the passive / active mode, the motor is actively controlled to apply a mechanical force to the hydraulic piston assembly, and the hydraulic system is not operated or the hydraulic system is operated to reduce, minimize, or eliminate the hydraulic force opposing the mechanical force of the motor. The passive / active mode can be used when the hydraulic system cannot generate sufficient hydraulic pressure, such as during a hydraulic system failure or partial failure.

[0046] At 418, the method includes operating the dual independent hybrid actuator system in the operating mode identified at 416 to achieve a targeted change in the state of the actuator system identified at 418. As an example, an electronic control system controls the hydraulic system and / or the motor of the actuator system to move the hydraulic piston assembly to a targeted actuator position.

[0047] If the operating mode is identified as the active / active mode at 416, then at 420, the method includes controlling the operation of one or more electro-hydraulic servo valves of the hydraulic system to create a targeted hydraulic differential at 422 between opposite sides of the hydraulic piston, the hydraulic differential pushing the piston rod in the targeted translation direction. For example, with respect to Figure 1 actuator system 100, where the targeted translation direction is the extension direction 102, the hydraulic differential includes a higher hydraulic pressure within the first sub-hydraulic chamber 112A compared to the second sub-hydraulic chamber 112B. In another example, in the case where the targeted translation direction is the retraction direction 104, the hydraulic differential includes a higher hydraulic pressure within the second sub-hydraulic chamber 112B compared to the first sub-hydraulic chamber 112A.

[0048] Simultaneously and in cooperation with the hydraulic force applied by the hydraulic differential at 422, at 424, the method includes controlling the operation of the motor in the targeted rotation direction, which pushes the piston rod in the targeted translation direction. Controlling the operation of the motor at 424 includes supplying electrical power to the motor in a sufficient amount and phase to cause the motor shaft to rotate in the targeted rotation direction, thereby causing the threaded shaft engaged with the hydraulic piston assembly to rotate. The total force pushing the piston rod in the targeted translation direction includes the sum of the hydraulic force applied by the hydraulic differential and the mechanical force applied by the motor to the hydraulic piston assembly. The total force applied by the hydraulic force and the mechanical force can cause the hydraulic piston assembly to move in the targeted translation direction, where the total force exceeds the force opposing such movement, such as the aerodynamic load on a flight control surface.

[0049] If the operating mode is recognized as the active / idle mode, then at 430, the method includes controlling the operation of one or more electro-hydraulic servo valves of the hydraulic system at 432 to generate a target hydraulic differential that pushes the piston rod in the target translation direction. Simultaneously and in coordination with the hydraulic force applied by the hydraulic differential at 432, at 434, the method includes controlling the operation of the motor such that the motor shaft rotates in a target rotational direction corresponding to the target translation direction of the piston rod in a manner that reduces, minimizes, or eliminates the resistance imposed by the motor (and its intermediate drivetrain) on the movement of the piston rod. Since the motor is not used to apply a mechanical force to the hydraulic piston assembly in the active / idle mode, for a given total force applied to the hydraulic piston assembly, the hydraulic pressure in the active / idle mode is greater than the hydraulic pressure in the active / active mode.

[0050] If the operating mode is recognized as the active / passive mode, then at 440, the method includes controlling the operation of one or more electro-hydraulic servo valves of the hydraulic system at 442 to generate a target hydraulic differential that pushes the piston rod in the target translation direction, and at 444 not operating the motor (i.e., not supplying power to the motor to cause an additional mechanical force on the hydraulic piston assembly). When the hydraulic piston assembly translates in the active / passive mode due to the hydraulic differential, the motor (and its intermediate drivetrain) rotates freely, and a resistance to such rotation is imposed on the hydraulic piston assembly.

[0051] If the operating mode is recognized as the passive / active mode, then at 450, the method includes controlling the operation of the motor at 454 such that the motor shaft rotates in a target rotational direction that pushes the piston rod in the target translation direction. At 452, the hydraulic system is not operated, or the restraining pressure differential that pushes the piston rod in a direction opposite to the target translation direction is reduced, minimized, or eliminated by controlling the operation of one or more electro-hydraulic servo valves and / or pressure reducing valves of the hydraulic system. For example, with respect to Figure 1 the actuator system 100, where the target translation direction is the extension direction 102, the hydraulic pressure in the second sub-hydraulic chamber 112B can be reduced, thereby reducing the hydraulic pressure on the hydraulic piston assembly that opposes the mechanical force applied by the motor. In another example, in the case where the target translation direction is the retraction direction 104, the hydraulic pressure in the first sub-hydraulic chamber 112A can be reduced, thereby reducing the hydraulic pressure on the hydraulic piston assembly that opposes the mechanical force applied by the motor.

[0052] From any of the operating modes 420, 430, 440, and 450 that are executed as part of operation 418, the method returns to 412, where additional input data is received at a subsequent point in time. As an example, in response to the hydraulic system not being able to generate a target hydraulic differential between opposite sides of a hydraulic piston as identified based on the additional input data received at 412, electrical power supplied to the motor can be increased, either alone or in combination with the hydraulic differential provided by the hydraulic system, to cause the motor shaft to rotate in a target rotational direction, which pushes the piston rod to move in a target translational direction to a target position. As a result of a transition between modes, the electrical power supplied to the motor can be increased, such as from an active / idle mode or an active / passive mode to an active / active mode or a passive / active mode. Conversely, the electrical power supplied to the motor can be decreased due to a transition from an active / active mode or a passive / active mode to an active / idle mode or an active / passive mode. Thus, during a first control operation (e.g., at a first point in time), one or more electrohydraulic servo valves of the hydraulic system can be operated to generate a target hydraulic differential that pushes the piston rod mounted to move in a target translational direction; and during a second control operation (e.g., at a second point in time), the motor can be operated to cause the motor shaft to rotate in a target rotational direction, which pushes the piston rod to move in a first translational direction, with or without the contribution of hydraulic pressure from the hydraulic system.

[0053] Figure 5 Schematically illustrates an example control architecture 500 for a dual independent hybrid actuator system, the dual independent hybrid actuator system including Figure 1 actuator system 100. The control architecture 500 can be implemented by an electronic control system such as Figure 1 electronic control system 170 to execute Figure 4 method 400 or portions thereof. In this example, the control architecture 500 is described in the context of a flight control surface within the dual independent hybrid actuator system 100 using Figure 1 as an example of a mechanical component controlled by the piston rod of the actuator system. For example, the actuator position can be obtained from position sensors 148A and 148B, or in the case of a stepper motor, from the motor, and the control surface position can be obtained from Figure 1 sensor 129. During fault-free operation, position control of the control surface can be achieved through a proportional position control loop of an electrohydraulic servo actuator (EHSA) controller, while load control can be achieved through an additional proportional position load control loop for an electric motor-driven ball screw (EMDLS), the electric motor-driven ball screw being an external cascade of the position control loop. In Figure 5 the ball screw actuator is taken as Figure 1Provided by an example of the electric motor 140. In the case of an EHSA failure or a loss of hydraulic power, control can thus be switched to the EMDLS position control. Figure 5 An example of a mode selector switch is also shown, which enables selection among the active / passive (A / P), active / active (A / A), and active / no-load (A / NL) operating modes described previously with reference to Figure 4 description.

[0054] Figure 6 An example planetary gear system 600 is shown, which may be included in the driveline 160 of the actuator system 100 of Figure 1 . The planetary gear system 600 includes an external ring gear 610 that meshes with a plurality of planetary gears 612, 614, 616, 618, etc., which in turn mesh with a sun gear 620. It should be understood that fewer or greater numbers of planetary gears may be used according to embodiments. In Figure 6 , the gear teeth are omitted because any suitable gear tooth configuration may be used to achieve a particular gear ratio of the planetary gear system 600. In the case of the actuator system 100, the sun gear 620 is mounted on a sun gear shaft 622, which has a rotational axis coaxial with the translational axis 125 of Figure 1 . The plurality of planetary gears are mounted to a carrier 626, which has a carrier shaft 624 that extends from a side of the planetary gear system 600 opposite the sun gear shaft 622. The carrier shaft 624 may also be coaxial with the translational axis 125. As an example, one of the shafts 622 or 624 may be mechanically coupled to the motor shaft 142 of the electric motor 140, while the other of the shafts 622 or 624 may be mechanically coupled to the threaded shaft 150 to provide a desired gear ratio.

[0055] In at least some examples, the methods and processes described herein may be bound to the computing system of one or more computing devices. Figure 7 An example computing system 700 is shown that may implement the method 400 for a dual independent hybrid actuator system of Figure 4 and the control architecture 500 of Figure 5 , the dual independent hybrid actuator system including the actuator system 100 of Figure 1 . The computing system 700 is an example of an electronic control system for a dual independent hybrid actuator system, such as the electronic control system 170 of Figure 1 . In Figure 7 , the computing system 700 is shown in simplified form as including a logic machine 710, a storage machine 712, and an input / output subsystem 714.

[0056] The logic machine 710 includes one or more physical devices configured to execute instructions. For example, the logic machine can be configured to execute instructions that are part of one or more applications, services, programs, routines, libraries, objects, components, data structures, or other logical constructs. Such instructions can be implemented to perform tasks, implement data types, transform the state of one or more components, achieve a technical effect, or otherwise achieve a desired result.

[0057] The logic machine 710 can include one or more processors configured to execute software instructions. Additionally or alternatively, the logic machine 710 can include one or more hardware or firmware logic machines configured to execute hardware or firmware instructions. The processors of the logic machine can be single-core or multi-core, and the instructions executed thereon can be configured for sequential, parallel, and / or distributed processing. Optionally, the various components of the logic machine can be distributed in two or more separate devices, which can be remotely located and / or configured for coordinated processing. For example, the logic machine 710 can be implemented as a first logic machine component that controls the operation of the hydraulic system 134 and a second logic machine component that controls the operation of the motor 140.

[0058] The storage machine 712 includes one or more physical devices configured to store instructions 724 and / or other data 722 that can be executed by the logic machine 710 to implement the methods and operations described herein. When implementing such methods and operations, the state of the storage machine 712 can be transformed—for example, to store different data. The storage machine 712 can include one or more removable devices and / or built-in devices. The storage machine 712 can include optical memory (e.g., CD, DVD, etc.), semiconductor memory (e.g., RAM, EPROM, EEPROM, etc.), and / or magnetic memory (e.g., hard disk drive, floppy disk drive, tape drive, MRAM, etc.), among others. The storage machine 712 can include volatile, non-volatile, dynamic, static, read / write, read-only, random access, sequential access, location-addressable, file-addressable, and / or content-addressable devices. Optionally, the various components of the storage machine can be distributed in two or more separate devices, which can be remotely located and / or configured for coordinated processing. For example, the storage machine 712 can be implemented as a first storage machine component that stores instructions and / or data for controlling the operation of the hydraulic system 134 and a second storage machine component that stores instructions and / or data for controlling the operation of the motor 140.

[0059] Aspects of the logic machine 710 and the storage machine 712 can be integrated together into one or more hardware-logic components. For example, such hardware logic components can include field programmable gate arrays (FPGAs), programmed and application specific integrated circuits (PASIC / ASICs), programmed and application specific standard products (PSSP / ASSPs), systems on a chip (SOCs), and complex programmable logic devices (CPLDs).

[0060] The input / output subsystem 714 can include one or more input devices and / or output devices or be connected to one or more input devices and / or output devices. Examples of input devices include the various sensors described herein (e.g., 129, 148A, 148B, motor 140 such as a stepper motor that identifies a rotational position, etc.), user input devices (e.g., cockpit controllers in an aircraft, computer mouse or controller, touch screen, natural language interface, etc.), communication interfaces (e.g., with another computing device), etc. Examples of output devices include motor 140, brake 149, hydraulic pump 136, servo valve 138, pressure reducing valve of a hydraulic system, user output interfaces (e.g., gauges, graphical display devices, audio speakers, indicator lights), etc.

[0061] Examples of the subject matter of the present disclosure are described in the paragraphs listed below.

[0062] A.1 A dual independent hybrid actuator system, comprising:

[0063] An actuator body that defines a hydraulic chamber within the interior of the actuator body, the actuator body further defining a first hydraulic fluid passage and a second hydraulic fluid passage that are in fluid communication with the hydraulic chamber; a hydraulic piston assembly, comprising: a hydraulic piston disposed within the hydraulic chamber and dividing the hydraulic chamber into a first sub-hydraulic chamber in fluid communication with the first hydraulic fluid passage and a second sub-hydraulic chamber in fluid communication with the second hydraulic fluid passage; and a piston rod mounted to the hydraulic piston and passing through the second sub-hydraulic chamber, the piston rod having a distal end that extends outward from the actuator body; a motor mounted to the actuator body, the motor having a motor shaft; and a threaded shaft mechanically coupled to the motor shaft of the motor, the threaded shaft passing through the first sub-hydraulic chamber and engaging a threaded port formed in the hydraulic piston assembly.

[0064] A.2 The dual independent hybrid actuator system according to paragraph A.1, wherein rotation of the motor shaft of the motor in a first rotational direction pushes the hydraulic piston to move in a first translational direction within the hydraulic chamber so that the distal end of the piston rod extends outward from the actuator body; and wherein rotation of the motor shaft of the motor in a second rotational direction opposite to the first rotational direction pushes the hydraulic piston to move in a second translational direction opposite to the first translational direction within the hydraulic chamber so that the piston rod retracts inwardly toward the actuator body.

[0065] A.3 The dual independent hybrid actuator system according to paragraph A.2, wherein a first pressure difference between the first sub-hydraulic chamber and the second sub-hydraulic chamber pushes the hydraulic piston to move in a first translation direction, wherein the first sub-hydraulic chamber has a higher hydraulic pressure than the second sub-hydraulic chamber; and wherein a second pressure difference between the first sub-hydraulic chamber and the second sub-hydraulic chamber pushes the hydraulic piston to move in a second translation direction opposite to the first translation direction, wherein the second sub-hydraulic chamber has a higher hydraulic pressure than the first sub-hydraulic chamber.

[0066] A.4 The dual independent hybrid actuator system according to paragraph A.3, further comprising: a hydraulic system in communication with a first hydraulic fluid passage and a second hydraulic fluid passage of the actuator body; and a control system configured to coordinate the operation of the electric motor and an electro-hydraulic servo valve of the hydraulic system so that: the hydraulic pressure in the first sub-hydraulic chamber is increased relative to the second sub-hydraulic chamber to achieve the first pressure difference, while operating the electric motor to rotate in a first rotation direction; and the hydraulic pressure in the second sub-hydraulic chamber is increased relative to the first sub-hydraulic chamber to achieve the second pressure difference, while operating the electric motor to rotate in a second rotation direction.

[0067] A.5 The dual independent hybrid actuator system according to any one of paragraphs A.1 to A.4, wherein the threaded shaft is coaxial with the piston rod or with the translation axis of the piston rod.

[0068] A.6 The dual independent hybrid actuator system according to paragraph A.5, wherein the motor shaft is coaxial with the piston rod or with the translation axis of the piston rod.

[0069] A.7 The dual independent hybrid actuator system according to any one of paragraphs A.1 to A.6, wherein the hydraulic piston assembly further comprises a ball screw nut defining a threaded port; and wherein the threaded shaft forms a ball screw shaft.

[0070] A.8 The dual independent hybrid actuator system according to any one of paragraphs A.1 to A.7, wherein the hydraulic piston assembly defines an internal chamber within the body of the hydraulic piston and / or the piston rod, the internal chamber receiving a portion of the threaded shaft extending through the threaded port; wherein the body of the hydraulic piston and / or the piston rod defines a fluid passage between the internal chamber and the first sub-hydraulic chamber, the fluid passage being independent of the threaded port; and wherein the hydraulic piston assembly further comprises an in-line check valve positioned along the fluid passage, the in-line check valve providing a greater resistance to hydraulic fluid flowing toward the internal chamber than to hydraulic fluid flowing from the internal chamber through the in-line check valve.

[0071] A.9 The dual independent hybrid actuator system according to any one of paragraphs A.1 to A.8, further comprising a transmission system; wherein the threaded shaft is mechanically coupled to the motor shaft of the electric motor via the transmission system; and wherein the transmission system provides a non-coincident effective transmission ratio between the motor shaft and the threaded shaft.

[0072] A.10 A dual independent hybrid actuator system as described in paragraph A.9, wherein the non-collocated effective gear ratio provides a reduced rotation rate of the threaded shaft relative to the rotation rate of the motor shaft.

[0073] A.11 A dual independent hybrid actuator system as described in paragraph A.9, wherein the drive train includes a planetary gear system.

[0074] A.12 A dual independent hybrid actuator system according to any one of paragraphs A.1 to A.11, wherein the actuator body is combined with the piston rod to form a connecting rod, which includes: a first bearing attachment point at the distal end of the piston rod, and a second bearing attachment point at the distal end of the actuator body opposite to the first bearing attachment point.

[0075] B.1 A method for controlling a dual independent hybrid actuator system, the method comprising: controlling the operation of an electro-hydraulic servo valve of a hydraulic system to generate a first hydraulic differential between opposite sides of a hydraulic piston, which pushes a piston rod mounted to the hydraulic piston to move in a first translational direction; during movement of the piston rod in the first translational direction, controlling the operation of a motor having a motor shaft mechanically connected to the hydraulic piston via a threaded shaft, wherein controlling the operation of the motor comprises providing power to the motor to rotate the motor shaft in a first rotational direction: this pushes the piston rod to move in the first translational direction in coordination with the force applied by the first hydraulic differential, or reduces the resistance of the motor to movement of the piston rod in the first translational direction.

[0076] B.2 The method according to paragraph B.1 also includes: in response to the hydraulic system being unable to generate a first hydraulic differential between opposite sides of the hydraulic piston, increasing the power provided to the motor to rotate the motor shaft in a first rotational direction, which pushes the piston rod to move to a target position in a first translational direction.

[0077] B.3 The method described in any of paragraphs B.1 to B.2 also includes: controlling the operation of the electro-hydraulic servo valve of the hydraulic system to generate a second hydraulic differential between opposite sides of the hydraulic piston, which pushes the piston rod to move in a second translation direction opposite to the first translation direction; during the movement of the piston rod in the second translation direction, controlling the operation of the motor by providing power to the motor to rotate the motor shaft in a second rotation direction opposite to the first rotation direction: this pushes the piston rod to move in the second translation direction in coordination with the force applied by the second hydraulic differential, or reduces the resistance of the motor to the movement of the piston rod in the second translation direction.

[0078] B.4 The method according to paragraph B.3 further includes: in response to the hydraulic system being unable to generate a second hydraulic difference between opposite sides of the hydraulic piston, increasing the power supplied to the motor to cause the motor shaft to rotate in a second rotational direction, which pushes the piston rod to move in a second translational direction to a target position.

[0079] B.5 The method according to any one of paragraphs B.1 to B.4, wherein controlling the operation of the motor includes supplying power to the motor to cause the motor shaft to rotate in a first rotational direction, which eliminates the resistance of the motor to the movement of the piston rod in a first translational direction.

[0080] C.1 A method of controlling a dual independent hybrid actuator system, the method including: during a first control operation, controlling the operation of an electro-hydraulic servo valve of the hydraulic system to generate a first hydraulic difference between opposite sides of the hydraulic piston, which pushes a piston rod mounted to the hydraulic piston to move in a first translational direction; and during a second control operation, controlling the operation of a motor having a motor shaft that is mechanically coupled to the hydraulic piston via a threaded shaft to cause the motor shaft to rotate in a first rotational direction, which pushes the piston rod to move in a first translational direction.

[0081] C.2 The method according to paragraph C.1, wherein the second control operation is performed in response to the hydraulic system being unable to generate a first hydraulic difference between opposite sides of the hydraulic piston during the first control operation.

[0082] C.3 The method according to any one of paragraphs C.1 to C.2, wherein the second control operation is performed simultaneously with the first control operation.

[0083] It should be understood that the configurations and / or techniques described herein are exemplary in nature and these specific examples should not be considered limiting as many variations are possible. The specific methods and operations described herein may represent one or more of any number of processing strategies. Accordingly, the various acts shown and / or described may be performed in the order shown and / or described, in other orders, in parallel, or omitted. Similarly, the order of the above operations may be changed according to embodiments. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various configurations and techniques, as well as other features, functions, acts, and / or characteristics disclosed herein, and any and all equivalents thereof.

Claims

1. A dual independent hybrid actuator system, wherein, The dual independent hybrid actuator system includes: An actuator body that defines a hydraulic chamber therein, and the actuator body further defines a first hydraulic fluid passage and a second hydraulic fluid passage that are in fluid communication with the hydraulic chamber; A hydraulic piston assembly, the hydraulic piston assembly including: A hydraulic piston disposed within the hydraulic chamber and dividing the hydraulic chamber into a first sub-hydraulic chamber in fluid communication with the first hydraulic fluid passage and a second sub-hydraulic chamber in fluid communication with the second hydraulic fluid passage, and A piston rod mounted to the hydraulic piston and passing through the second sub-hydraulic chamber, the piston rod having a distal end that extends outwardly from the actuator body; A motor mounted to the actuator body, the motor having a motor shaft; and A threaded shaft mechanically coupled to the motor shaft of the motor, the threaded shaft passing through the first sub-hydraulic chamber and engaging a threaded port formed in the hydraulic piston assembly; Wherein the hydraulic piston assembly defines an internal chamber within the body of the hydraulic piston and / or the piston rod, and the internal chamber houses a portion of the threaded shaft that extends through the threaded port; Wherein the body of the hydraulic piston and / or the piston rod defines a fluid passage between the internal chamber and the first sub-hydraulic chamber, and the fluid passage is independent of the threaded port; and Wherein the hydraulic piston assembly further includes an in-line check valve positioned along the fluid passage, and the in-line check valve provides a greater resistance to hydraulic fluid flowing toward the internal chamber than to hydraulic fluid flowing from the internal chamber through the in-line check valve.

2. The dual independent hybrid actuator system according to claim 1, wherein, Rotation of the motor shaft of the motor in a first rotational direction pushes the hydraulic piston to move in a first translational direction within the hydraulic chamber, so that the distal end of the piston rod extends outwardly from the actuator body; And Wherein rotation of the motor shaft of the motor in a second rotational direction opposite to the first rotational direction pushes the hydraulic piston to move in a second translational direction opposite to the first translational direction within the hydraulic chamber, so that the piston rod retracts inwardly toward the actuator body.

3. The dual independent hybrid actuator system according to claim 2, wherein, A first pressure difference between the first sub-hydraulic chamber and the second sub-hydraulic chamber pushes the hydraulic piston to move in the first translational direction, wherein the first sub-hydraulic chamber has a higher hydraulic pressure than the second sub-hydraulic chamber; And Wherein a second pressure difference between the first sub-hydraulic chamber and the second sub-hydraulic chamber pushes the hydraulic piston to move in the second translational direction opposite to the first translational direction, wherein the second sub-hydraulic chamber has a higher hydraulic pressure than the first sub-hydraulic chamber.

4. The dual independent hybrid actuator system according to claim 3, further comprising: A hydraulic system in communication with the first hydraulic fluid passage and the second hydraulic fluid passage of the actuator body; And A control system configured to coordinate the operation of the motor and an electro-hydraulic servo valve of the hydraulic system so that: Increase the hydraulic pressure in the first sub-hydraulic chamber relative to the second sub-hydraulic chamber to achieve the first pressure difference, and simultaneously operate the motor to rotate in the first rotational direction; And Increase the hydraulic pressure in the second sub-hydraulic chamber relative to the first sub-hydraulic chamber to achieve the second pressure difference, and simultaneously operate the motor to rotate in the second rotational direction.

5. The dual independent hybrid actuator system according to claim 1, wherein, The threaded shaft is coaxial with the piston rod or with the translational axis of the piston rod.

6. The dual independent hybrid actuator system according to claim 5, wherein, The motor shaft is coaxial with the piston rod or with the translational axis of the piston rod.

7. The dual independent hybrid actuator system according to claim 1, wherein, The hydraulic piston assembly further includes a ball screw nut that defines the threaded port; and wherein the threaded shaft forms a ball screw shaft.

8. The dual independent hybrid actuator system according to claim 1, further comprising a transmission system; Among them, The threaded shaft is mechanically coupled to the motor shaft of the motor via the transmission system; and wherein the transmission system provides a non-collinear effective transmission ratio between the motor shaft and the threaded shaft.

9. The dual independent hybrid actuator system according to claim 8, wherein, The non-collinear effective transmission ratio provides a reduced rotational speed of the threaded shaft relative to the rotational speed of the motor shaft.

10. The dual independent hybrid actuator system according to claim 8, wherein, The transmission system includes a planetary gear system.

11. The dual independent hybrid actuator system according to claim 1, wherein, The actuator body and the piston rod are combined to form a connecting rod, and the connecting rod includes: A first bearing attachment point at the distal end of the piston rod, and A second bearing attachment point at the distal end of the actuator body opposite to the first bearing attachment point.

12. A method of controlling a dual independent hybrid actuator system according to claim 1, wherein, The method includes: Controlling the operation of an electro-hydraulic servo valve of a hydraulic system to generate a first hydraulic pressure difference between opposite sides of a hydraulic piston, the first hydraulic pressure difference pushing a piston rod mounted to the hydraulic piston to move in a first translational direction; During the movement of the piston rod in the first translational direction, controlling the operation of a motor having a motor shaft mechanically coupled to the hydraulic piston via a threaded shaft, wherein controlling the operation of the motor includes supplying power to the motor to cause the motor shaft to rotate in a first rotational direction such that: Push the piston rod to move in the first translational direction in coordination with the force applied by the first hydraulic pressure difference, or Reduce the resistance of the motor to the movement of the piston rod in the first translational direction.

13. The method according to claim 12, further comprising: In response to the hydraulic system being unable to generate the first hydraulic pressure difference between opposite sides of the hydraulic piston, increasing the power supplied to the motor to cause the motor shaft to rotate in the first rotational direction, which pushes the piston rod to move to a target position in the first translational direction.

14. The method according to claim 12, further comprising: Controlling the operation of the electro-hydraulic servo valve of the hydraulic system to generate a second hydraulic pressure difference between opposite sides of the hydraulic piston, the second hydraulic pressure difference pushing the piston rod to move in a second translational direction opposite to the first translational direction; During the movement of the piston rod in the second translational direction, controlling the operation of the motor by supplying power to the motor to cause the motor shaft to rotate in a second rotational direction opposite to the first rotational direction: such that: Cause the piston rod to move in the second translation direction in coordination with the force applied by the second hydraulic differential, or Reduce the resistance of the motor to the movement of the piston rod in the second translation direction.

15. The method according to claim 14, further comprising: In response to the hydraulic system being unable to generate the second hydraulic differential between opposite sides of the hydraulic piston, increasing the power supplied to the motor to cause the motor shaft to rotate in the second rotation direction, which causes the piston rod to move in the second translation direction to a target position.

16. The method according to claim 12, wherein, Controlling the operation of the motor includes supplying power to the motor to cause the motor shaft to rotate in a first rotation direction, which eliminates the resistance of the motor to the movement of the piston rod in the first translation direction.

17. A method of controlling a dual independent hybrid actuator system according to claim 1, wherein, The method includes: During a first control operation, controlling the operation of an electro-hydraulic servo valve of a hydraulic system to generate a first hydraulic differential between opposite sides of a hydraulic piston, the first hydraulic differential causing a piston rod mounted to the hydraulic piston to move in a first translation direction; and During a second control operation, controlling the operation of a motor having a motor shaft that is mechanically coupled to the hydraulic piston via a threaded shaft to cause the motor shaft to rotate in the first rotation direction, which causes the piston rod to move in the first translation direction.

18. The method according to claim 17, wherein, Performing the second control operation in response to the hydraulic system being unable to generate the first hydraulic differential between opposite sides of the hydraulic piston during the first control operation.

19. The method according to claim 17, wherein, The second control operation is performed simultaneously with the first control operation.

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