Multi-channel servo actuating system and synchronous control method thereof

Abstract

The application belongs to the technical field of flight control servo actuation, and discloses a multi-channel servo actuation system and a synchronous control method thereof. The system comprises a rudder set, a control mechanism and a servo controller. The rudder set comprises at least two rudders, each of which is provided with a rudder sensor; the control mechanism is provided with a control mechanism sensor for detecting rotary motion caused by inconsistent motion of the rudders; the servo controller receives flight control instructions, synchronously collects data of the sensors, generates compensation signals through comprehensive operation and sends the compensation signals to the rudders to coordinate multi-channel motion and improve synchronous precision. The application directly detects and closes loop control of motion synchronous error, effectively solves the problem of inconsistent motion of multiple rudders caused by factors such as sensor precision and assembly error in the traditional system, is suitable for electro-hydraulic and electromechanical actuation systems and has the advantages of low implementation cost and strong adaptability.

Description

Technical Field

[0001] This invention belongs to the technical field of servo actuation subsystem in flight control system, specifically relating to a multi-channel servo actuation system and its synchronization control method, which is used to improve the synchronization accuracy of multi-channel servo motor motion and is applicable to the control surface or rotor control of aircraft such as helicopters and fixed-wing aircraft. Background Technology

[0002] Flight control systems control aircraft by using servo actuators to control the control mechanism and thus the propeller pitch. Compared to single-servo control mechanisms, multi-servo servo systems offer superior control stiffness, shorter control idle travel, and more redundancy. However, in multi-servo servo systems, factors such as the control accuracy of each channel servo, external disturbances, sensor accuracy, and component manufacturing and assembly errors make it difficult to achieve consistent output from multiple servos. This can lead to control mechanism tilt, preventing the desired state from being reached and affecting propeller pitch control. Servos typically use LVDT sensors to collect linear displacement outputs and implement closed-loop control through feedback. As the output travel of the LVDT sensor increases, its control accuracy deteriorates, leading to decreased servo control accuracy. The cumulative control errors from multiple servos exacerbate control mechanism tilt. Control mechanism tilt results in unexpected periodic pitch changes, generating additional loads, causing structural fatigue, affecting product lifespan, and increasing product weight.

[0003] Improving sensor accuracy, reducing machining and manufacturing errors, employing differential pressure equalization technology, and adopting force integration measures at the control mechanism are common methods for reducing motion errors and improving the consistency of servo motor output. Improving sensor accuracy primarily involves enhancing the accuracy of the LVDT (Low Voltage Detector) sensor in the servo actuator system. Improving machining and assembly accuracy mainly involves enhancing the accuracy of hydraulic distribution and execution mechanisms such as servo motor valves and actuator cylinders. Differential pressure equalization technology is a common method for resolving force disputes in hydraulic actuators. It requires collecting pressure values ​​from different servo motor channels as control input, calculating the pressure difference, and generating a compensation signal from the differential pressure controller. This compensation signal is then superimposed on the flow control loop of each servo motor. However, in hydraulic actuators, position synchronization is a result of differential pressure equalization technology, not its control objective, thus its effectiveness is limited. Force integration measures at the control mechanism generally involve strengthening the strength, rigidity, and dimensional tolerances of components at the control mechanism to counteract inconsistencies in the movement of different servo motors.

[0004] Given the current level of sensor technology, methods to improve sensor accuracy have certain limitations. High-precision displacement sensors are expensive, have low production capacity, and poor reliability. Methods to improve processing and assembly accuracy often lead to a significant increase in costs and cannot cope with inconsistencies caused by external disturbances and command errors. The application of differential pressure equalization technology in electro-hydraulic servo actuation systems has limited scope, and position synchronization is a result of differential pressure equalization technology, not its control objective, thus its effectiveness is limited. Measures to integrate forces at the control mechanism generally involve strengthening the strength, rigidity, and dimensional tolerances of the parts at the control mechanism to resist inconsistencies in the movement of each servo motor. This approach increases the system weight and complicates the testing and verification process.

[0005] Therefore, there is an urgent need to propose a control method and system that can directly detect and suppress multi-channel motion asynchrony, and effectively improve the motion consistency of multi-servo systems without significantly increasing hardware costs. Summary of the Invention

[0006] To address the problem of poor motion consistency among servo motors in existing multi-channel servo actuation systems due to limited sensor accuracy and cumulative errors, this invention proposes a multi-channel servo actuation system and its synchronization control method. By adding a sensor for directly detecting the motion synchronization error of each channel and designing a corresponding synchronization closed-loop controller, real-time monitoring and dynamic compensation of the inconsistency of multi-channel motion are achieved, thereby significantly improving the system's synchronization control accuracy without relying on high-precision single-channel sensors.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] Firstly, a multi-channel servo actuation system is provided, comprising:

[0009] A servo assembly includes at least two servos, each equipped with a servo sensor for detecting the output displacement of that servo;

[0010] The control mechanism, as the controlled object, is equipped with a control mechanism sensor to detect the rotational motion of the control mechanism caused by the inconsistent movement of each servo motor. This rotational motion characterizes the motion synchronization error between each servo motor.

[0011] The servo controller, which communicates with the flight control computer, is used for:

[0012] Receive control commands from the flight control system;

[0013] Simultaneously acquire displacement feedback signals from each servo motor sensor and rotational motion signals from the control mechanism sensors;

[0014] Based on the above signals, comprehensive control calculations are performed to generate compensation control signals for each servo motor;

[0015] The compensation signal is sent to the corresponding servo motor, driving each servo motor to move in coordination, so that the actual movement of the control mechanism is consistent with the command.

[0016] As a further technical solution of the present invention: the servo motor is the actuator of the servo actuation system, and can be selected from one or more of the following, namely electro-hydraulic servo valve actuator (EHSV), direct drive valve actuator (DDV), electro-hydraulic actuator (EHA) or electromechanical actuator (EMA), depending on the energy source and drive form.

[0017] As a further technical solution of the present invention: the servo sensor detects the output stroke of the servo and feeds it back to the servo controller. Its detection error is proportional to the extension amount of the servo. The detection accuracy is the worst when the servo is at its limit stroke position. The stroke errors of each servo are superimposed at the control mechanism, which aggravates the rotational motion.

[0018] As a further technical solution of the present invention: the control mechanism is used to control the propeller pitch angle of the aircraft, and its motion includes linear motion along its own central axis and rotational motion about an axis perpendicular to the central axis, wherein the rotational motion is caused by the inconsistent motion of each servo motor and serves as the object of motion synchronization error detection.

[0019] As a further technical solution of the present invention: the control mechanism sensor is arranged at a position that can sensitively reflect the differences in motion of each servo motor, and the physical quantity it detects can be angle, length, strain or stress, and has high precision characteristics within the range of the sensor, and its precision is higher than that of a single servo motor displacement sensor at the limit stroke.

[0020] As a further technical solution of the present invention: the servo controller further includes:

[0021] Single-channel servo control module: performs independent closed-loop position control for each servo motor, typically using a PID control algorithm;

[0022] Synchronization controller: Receives motion synchronization error signals from the sensors of the control mechanism, performs closed-loop adjustment on them, and generates a global compensation signal for coordinating multi-channel motion;

[0023] Weight Distributor: Distributes the global compensation signal to each servo according to a preset strategy. The distribution coefficient can be a fixed value or dynamically adjusted according to the status of each servo.

[0024] Amplitude limiting module: Limits the amplitude of the compensation signal distributed to each channel to prevent excessive compensation commands in case of system failure or abnormality, thus ensuring system safety.

[0025] As a further technical solution of the present invention: the weight allocator adopts a fixed weight allocation coefficient or a dynamic weight allocation coefficient;

[0026] The dynamic weight allocation coefficient is dynamically adjusted based on at least one of the following factors: static characteristics, dynamic characteristics, and real-time operating status of each servo motor.

[0027] As a further technical solution of the present invention: the single-channel servo control module adopts a PID control algorithm;

[0028] The synchronization controller uses a PID control algorithm to perform closed-loop adjustment of motion synchronization error.

[0029] Secondly, a synchronous control method for a multi-channel servo actuation system is provided, including the following steps:

[0030] S1: The system receives control commands from the flight control computer and ensures consistency of commands across control channels through cross-channel data links;

[0031] S2: Each single-channel servo control module generates a single-channel control signal based on the control command of this channel and the feedback from the servo sensor, driving the corresponding servo to move and forming a single-channel position closed loop;

[0032] S3: All servos drive the control mechanism together; the control mechanism sensor detects the rotational motion of the control mechanism caused by the inconsistent movement of each servo and outputs it as a motion synchronization error signal.

[0033] S4: The synchronization controller receives the motion synchronization error signal and generates a global compensation signal through a closed-loop control algorithm;

[0034] S5: The weight distributor distributes the global compensation signal to each servo according to the performance characteristics, real-time status or preset weight coefficient of each servo, forming a channel compensation signal.

[0035] S6: After limiting the amplitude of each channel compensation signal, it is superimposed on the original control command of the corresponding servo motor to correct the servo motor movement, thereby reducing the motion synchronization error between multiple channels.

[0036] As a further technical solution of the present invention: in the weight allocation step, the weight is set by a fixed proportional coefficient or dynamically adjusted according to the performance parameters, real-time status and system preset strategy of each servo motor;

[0037] In the synchronization control step, a PID control algorithm is used to perform closed-loop adjustment of the motion synchronization error;

[0038] The amplitude limiting process is used to limit the amplitude of the compensation signal of each channel to prevent instability or damage caused by control system failure.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] 1. High synchronization accuracy: By directly detecting the motion synchronization error of the control mechanism and performing closed-loop control, multi-channel inconsistency is suppressed at the system level. It is not affected by the decrease in accuracy of single-channel sensors with stroke, and significantly improves the motion synchronization accuracy of multiple servo motors.

[0041] 2. Controllable cost: It eliminates the need for extremely high-precision single-channel displacement sensors, reducing system hardware costs and manufacturing difficulty; synchronous compensation is achieved through control algorithms, making it economical and feasible.

[0042] 3. Wide applicability: This method does not depend on the specific type of actuator and is applicable to both electro-hydraulic servo actuation systems and electromechanical actuation systems, exhibiting good versatility and portability.

[0043] 4. Safe and reliable: The limiting module prevents the compensation signal from being too large. Combined with the weight allocation mechanism, the control strategy can be dynamically adjusted when a single channel fails or its performance degrades, thereby improving the system's fault tolerance and safety.

[0044] 5. Excellent dynamic performance: It supports both fixed weight and dynamic weight allocation methods, and can adaptively adjust the compensation amount according to the real-time status of each channel to improve the synchronous control performance of the system under changing operating conditions.

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the composition structure of the multi-channel servo actuation system in an embodiment of the present invention;

[0047] Figure 2 This is a block diagram illustrating the principle of the synchronization control method in an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some embodiments of this invention, but not all embodiments.

[0049] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0050] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0051] The following is in conjunction with the appendix Figure 1-2The embodiments of the present invention will be described in detail below. Example 1

[0052] 1. Multi-channel servo actuation system:

[0053] like Figure 1 As shown, this embodiment discloses a dual-channel servo actuation system, including a servo controller, servo A, servo B, a control mechanism, and corresponding sensors.

[0054] The servo controller receives commands from the flight control computer and outputs control current to servo A and servo B through internal calculations. Each servo can use an EHA actuator, which integrates a motor and ball screw to convert electrical energy into linear motion output. Servo A and servo B are connected to the control mechanism via mechanical linkages, jointly driving it to move linearly along the central axis, thereby changing the rotor pitch.

[0055] Each servo is equipped with an LVDT (Linear Variable Differential Transformer) displacement sensor to detect the displacement of the servo output lever in real time and feed it back to the servo controller. The control mechanism is equipped with a high-precision tilt sensor to detect the rotation angle around the horizontal axis caused by the asynchronous output of the two servos during movement.

[0056] The servo controller is implemented using a digital signal processor, and its software functional modules include:

[0057] Two independent single-channel PID control modules, corresponding to servo A and servo B respectively, realize closed-loop position control for each channel;

[0058] A synchronous PID controller receives the tilt sensor signal as the synchronization error input and outputs a global compensation value.

[0059] In this embodiment, the weight allocation unit uses fixed weights to allocate the global compensation value to the two channels in a 1:1 ratio.

[0060] The limiting module sets the upper limit of the compensation signal to ±10% of the command signal.

[0061] During operation, if the output displacement of servo motor A and servo motor B differs due to manufacturing differences or disturbances, the control mechanism will tilt. After the tilt sensor detects this angle, the synchronous controller generates a compensation signal, which is then distributed and limited and superimposed on the original commands of the two servo motors, making the outputs of the two servo motors more consistent, thereby reducing the tilt of the control mechanism.

[0062] 2. Synchronization control method flow:

[0063] like Figure 2 As shown, this embodiment details the execution flow of the synchronization control method:

[0064] The flight control system issues pitch control commands, which are then synchronously transmitted to the control modules of channel A and channel B via cross-channel communication.

[0065] Channel A controller, based on instructions and LVDT feedback, performs PID calculations and outputs a control quantity to drive servo motor A to move; the same applies to channel B.

[0066] The outputs of servo motor A and servo motor B act on the control mechanism through a linkage device, and the actual movement of the control mechanism is a combination of the outputs of the two channels;

[0067] An tilt sensor mounted on the control mechanism detects its rotation angle in real time. If the angle is not zero, it indicates that the two servo motors are not moving in sync.

[0068] The angle signal is fed into the synchronous PID controller as a synchronization error, and the controller outputs a global compensation signal U_comp.

[0069] The weight allocator assigns U_comp to U_compA and U_compB according to a preset strategy (in this example, fixed weights kA=0.5, kB=0.5);

[0070] The amplitude limiting module limits the amplitude of U_compA and U_compB to ensure that it does not exceed the safe range;

[0071] The compensation signal after amplitude limiting is superimposed on the original control commands of channel A and channel B respectively to form the corrected drive signal;

[0072] Servo motors A and B adjust their outputs according to the corrected instructions, reducing the tilt angle of the control mechanism and achieving synchronized movement.

[0073] 3. Application of variable weight allocation:

[0074] In another preferred embodiment, the weight allocator employs a dynamic weighting strategy. The system monitors the actual displacement, velocity, and load force of each servo in real time, and calculates the weight coefficient of each channel at the current moment by combining the rated bandwidth and inertia characteristics of each servo. For example, when a servo's response is lagging, its compensation weight is appropriately increased to accelerate the synchronization adjustment process. This method is particularly suitable for situations where the dynamic characteristics of each servo are inconsistent or there are minor faults, and can improve the overall coordination performance of the system.

[0075] This invention directly detects multi-channel motion synchronization errors by adding sensors to the control mechanism and designs a control architecture including a synchronization controller, a weight allocator, and a limiting module to achieve real-time closed-loop adjustment of the motion consistency of multiple servo motors. This method has a clear structure, is flexible in implementation, and can effectively improve the system's synchronization accuracy and robustness, making it suitable for various servo actuation applications requiring multi-channel coordination. Example 2

[0076] To address the issue of poor motion consistency among servo motors due to the limited accuracy of existing sensors, this invention provides a multi-channel servo actuation system and its synchronous control method. By adding multi-channel inconsistency measurement sensors to the independent closed-loop control of each channel, the inconsistency of motion among each channel can be directly measured and controlled. This method is unaffected by the output stroke of the servo motor and is effective for inconsistencies caused by signal terminals, actuator terminals, and external disturbances. It can be applied to both electro-hydraulic servo actuation systems and electromechanical actuation systems.

[0077] This invention provides a multi-channel servo actuation system, comprising:

[0078] A servo assembly, which has at least two servos, each equipped with a servo sensor;

[0079] The control mechanism is equipped with control mechanism sensors for measuring the rotational motion of the control mechanism;

[0080] The servo controller receives control commands from the flight control computer and simultaneously collects data from the servo sensors and control mechanism sensors on each channel. It performs comprehensive calculations on the control commands from the flight control computer and the data from the servo sensors and control mechanism sensors on each channel, and sends the calculation results to the servos to ensure that the servo outputs are consistent with the control commands.

[0081] Furthermore, the servo motor is the actuator of the servo actuation system, and according to the different energy types and control components, it is divided into EHSV actuator, DDV actuator, EHA actuator, and EMA actuator.

[0082] Furthermore, the control mechanism is the control object of the servo actuation system and is used to control the propeller pitch angle; the movement of the control mechanism is divided into linear movement along its central axis and rotational movement about an axis perpendicular to its central axis. The rotational movement is caused by the inconsistent movement of the servo motors in each channel.

[0083] Furthermore, the servo sensor is used to measure the servo motor's output motion stroke and feed it back to the servo controller;

[0084] Since the position error of the servo sensor is proportional to the extension of the servo, the sensor accuracy is worst when the servo is at its limit position.

[0085] The cumulative effect of the travel errors of each servo motor caused the unexpected rotational motion of the control mechanism to become more severe.

[0086] Furthermore, the control mechanism sensor is used to measure the rotational motion of the control mechanism, which represents the inconsistency of the motion of the various channel servo motors driving the control mechanism, i.e., motion synchronization error.

[0087] The selected position of the sensor at the control mechanism must ensure that the signal collected by the sensor can reflect the motion synchronization error of each channel and that the selected sensor can maintain high accuracy throughout the entire motion range. The selected sensor must be consistent with the type of signal collected and have high acquisition accuracy. The motion synchronization error can be expressed by angle, length, strain, and stress after being collected and processed by the sensor.

[0088] Furthermore, the servo controller includes a single-channel servo control module, a synchronization controller, a weight allocator, and a limiting module;

[0089] The single-channel servo control module is used to perform servo control on the single-channel actuator.

[0090] The synchronization controller is used to perform closed-loop control on the motion synchronization error of each channel actuator. The coupling compensation signal is processed based on the high-precision motion synchronization error signal and command signal information collected at the control mechanism to generate the compensation signal required for coordinated control.

[0091] The weight allocator is used to distribute the compensation signal generated by the synchronization controller to each channel actuator;

[0092] The limiting module is used to limit the compensation signal to avoid serious impact on the servo control system caused by system failure.

[0093] Furthermore, the motion synchronization error signal can be simply allocated to each channel using a fixed ratio, i.e., using a fixed weight allocation coefficient.

[0094] Alternatively, dynamic weight allocation coefficients can be used to allocate weights based on the static / dynamic performance and current specific state of each channel actuator, i.e., variable weight allocation coefficients.

[0095] This invention provides a synchronous control method for a multi-channel servo actuation system, comprising the following steps:

[0096] The servo actuation system receives control command signals from the upper-level system. The control command signals are transmitted to each channel control module. The modules achieve consistency of control information through cross-channel data links.

[0097] The single-channel servo control module generates a control signal based on the channel control command and feedback signal. After control calculation and servo amplification, the control signal drives the servo motor to move. The motion signal is collected by the servo motor sensor and fed back to the single-channel servo controller, forming a closed-loop control loop of the single-channel servo controller. However, the single-channel control accuracy deteriorates as the servo motor travel increases, and it cannot maintain good control accuracy.

[0098] The combined movement of each channel servo motor drives the control mechanism, which in turn drives the propeller blades to produce pitch. Due to synchronization errors in the movement of each channel servo motor, an undesirable rotational motion is generated at the control mechanism, which is captured by the control mechanism's sensors.

[0099] The system collects motion synchronization error signals measured by the sensors of the control mechanism, transmits the motion synchronization error signals to the synchronization controller, and the synchronization controller performs closed-loop control on the motion synchronization error to generate the compensation signals required for coordinated control.

[0100] The compensation signal is transmitted to the weight allocator, which generates weight allocation coefficients based on the capabilities and status of each channel actuator and the preset coefficients of the designer.

[0101] The compensation signal is multiplied by the weighting coefficient to form the compensation signal for each channel. In order to avoid serious consequences caused by control system failure, the compensation signal for each channel needs to be processed by the amplitude limiting module before it is distributed to the servo motor of each channel. The processed compensation signal is superimposed on the original channel control command of each servo motor to drive the actuator to generate motion in order to reduce the synchronization error of each channel.

[0102] In summary, the advantages of this invention are as follows:

[0103] 1. This invention proposes a multi-channel servo actuation system that directly measures physical quantity signals that comprehensively reflect the motion errors of each channel's actuators. A synchronization controller and a control controller are used to process the error signals, generate compensation signals, and rationally distribute the compensation signals to each channel's actuators. This invention reduces the motion errors of each channel in the servo actuation system and improves the synchronization accuracy of the actuators; it eliminates the need for developing high-precision sensors, resulting in low implementation costs; this method is applicable to both electro-hydraulic servo actuator control and electromechanical actuator servo control.

[0104] 2. By setting a sensor for the control mechanism, this invention directly measures a signal that comprehensively reflects the motion error of each channel. This error signal is not directly related to the motion stroke, motion speed, etc. of each channel, thus maintaining a high positional accuracy and improving the synchronous control accuracy of the servo actuation system.

[0105] 3. The present invention is equipped with a synchronization controller for closed-loop control of the inconsistency of motion of each channel servo motor. The synchronization controller processes information such as high-precision motion synchronization error signal and command signal collected from the control mechanism to generate compensation signal required for coordinated control.

[0106] 4. The present invention is equipped with a weight allocator for allocating the compensation signal generated by the synchronous controller. The weight allocator can use a fixed value for the allocation coefficient, or it can be dynamically adjusted during the control process. The dynamic adjustment of the allocation coefficient is generally based on the static and dynamic characteristics of each channel (bandwidth capability, inertia, start-up speed, etc.) and the state within the control cycle (real-time motion speed, bandwidth margin, etc.).

[0107] 5. The present invention includes a compensation limiting measure, which refers to setting a limiting module for the compensation signal to avoid serious impact on the servo control system caused by compensation control failure. Example 3

[0108] This invention discloses a multi-channel servo actuation system, comprising a servo controller, servo motors for each channel, a control mechanism, servo motor sensors for each channel, and sensors for the control mechanism, etc. Figure 1 The multi-channel servo actuation system is shown in the diagram. The multi-channel servo actuation system receives commands from the flight control system, processes them through the servo actuation controller, and outputs control current to each channel servo. Each servo drives the control mechanism to change the propeller pitch angle, thereby controlling the aircraft's forward speed.

[0109] The primary function of a servo controller is to achieve closed-loop control of the servo actuation loop. It receives control commands from the flight control computer and simultaneously acquires data from the servo sensors and control mechanism sensors across all channels. It compares and calculates the control commands from the flight control system with the sensor data fed back from the servos and control mechanisms, sending the results to the servos to ensure consistency between servo outputs and control commands. Common architectures include analog control, digital control, and hybrid analog-digital control.

[0110] A servo motor is the actuator of a servo actuation system. Depending on the energy source and control components, it can be classified as an EHSV actuator, DDV actuator, EHA actuator, EMA actuator, etc. Its main function is to convert hydraulic or electrical energy into mechanical energy for displacement output based on servo controller commands, thereby driving the control mechanism.

[0111] The control mechanism is the controlled object of the servo actuation system, used to control the propeller pitch angle. The motion of the control mechanism can be divided into linear motion along its central axis and rotational motion about an axis perpendicular to its central axis. The rotational motion is caused by inconsistent motion of the servo motors in each channel, which is undesirable motion and generates additional loads and structural fatigue problems.

[0112] Servo sensor is mounted on the servo motor to measure the servo motor's output motion travel and feed it back to the servo controller. Since the servo sensor position error is proportional to the servo motor's extension, the sensor accuracy is worst when the servo motor is at its limit travel position. The cumulative effect of the travel errors of each servo motor exacerbates the unintended rotational motion at the control mechanism.

[0113] The control mechanism sensor measures the rotational motion of the control mechanism, which represents the inconsistency in the motion of the various servo motors driving the control mechanism, i.e., the motion synchronization error. This motion synchronization error is independent of the output stroke of a single-channel servo motor. Compared to the servo motor's stroke, the motion synchronization error of each channel servo motor is much smaller. Therefore, the control mechanism sensor can maintain high accuracy, ensuring that the motion synchronization error control accuracy is much higher than the single-channel motion control accuracy. The placement and type of the sensor at the control mechanism must be carefully selected. The selected location must ensure that the signal acquired by the sensor can reflect the motion synchronization error of each channel and that the selected sensor can maintain high accuracy throughout the entire motion range. The selected sensor must be consistent with the type of signal acquired and have high acquisition accuracy. The motion synchronization error, after being acquired and processed by the sensor, can be expressed through physical quantities such as angle, length, strain, and stress.

[0114] The servo actuation control system mainly consists of a single-channel servo control module, a synchronization controller, a weight allocator, and a limiting module. For example... Figure 2 The schematic diagram of the servo actuation synchronous control method is shown.

[0115] A single-channel servo control module is used for servo control of a single-channel actuator. Since the types of actuators in each channel are not necessarily the same (e.g., electro-hydraulic actuators, electromechanical actuators, etc.), the single-channel servo control must be tailored to the specific characteristics of each actuator. Single-channel servo control generally employs the PID control method.

[0116] The synchronization controller is used to perform closed-loop control of the motion synchronization error of each channel servo motor. The coupling compensation signal is processed based on the high-precision motion synchronization error signal and command signal collected from the control mechanism to generate the compensation signal required for coordinated control. This signal is generally controlled by PID.

[0117] The weight allocator acts as a scheduler, distributing the compensation signal generated by the synchronization controller to the servos in each channel. Each channel can simply use a fixed ratio to distribute the motion synchronization error signal, i.e., a fixed weight allocation coefficient; or it can use a dynamic weight allocation coefficient based on the static / dynamic performance and current state of each channel's actuator, i.e., a variable weight allocation coefficient.

[0118] An amplitude limiting module is provided, which is used to limit the amplitude of the compensation signal to avoid serious impact on the servo control system due to system failure.

[0119] This invention discloses a synchronous control method for a multi-channel servo actuation system, which includes the following steps:

[0120] The servo actuation system receives control command signals from the upper-level system. The control command signals are transmitted to each channel control module. The modules achieve consistency of control information through cross-channel data links.

[0121] The single-channel servo control module generates a control signal based on the channel control command and feedback signal. After control calculation and servo amplification, the control signal drives the servo motor to move. The motion signal is collected by the servo motor sensor and fed back to the single-channel servo controller, forming a closed-loop control loop of the single-channel servo controller. However, the single-channel control accuracy deteriorates as the servo motor travel increases, and it cannot maintain good control accuracy.

[0122] The combined movement of the servo motors in each channel drives the control mechanism, which in turn causes the propeller blades to change pitch. Due to synchronization errors in the movements of the servo motors in each channel, an undesirable rotational motion occurs at the control mechanism, which is captured by the control mechanism's sensors.

[0123] The system collects motion synchronization error signals measured by the sensors of the control mechanism, transmits the motion synchronization error signals to the synchronization controller, and the synchronization controller performs closed-loop control on the motion synchronization error to generate the compensation signals required for coordinated control.

[0124] The compensation signal is transmitted to the weight allocator, which generates weight allocation coefficients based on the capabilities and status of each channel actuator and the preset coefficients of the designer.

[0125] The compensation signal is multiplied by the weighting coefficient to form the compensation signal for each channel. In order to avoid serious consequences caused by control system failure, the compensation signal for each channel needs to be processed by the amplitude limiting module before it is distributed to the servo motor of each channel. The processed compensation signal is superimposed on the original channel control command of each servo motor to drive the actuator to generate motion in order to reduce the synchronization error of each channel.

[0126] In summary, this invention provides a multi-channel servo actuation system and a control method for directly measuring the motion synchronization error of each channel's control mechanism, processing the error signal, and generating a compensation signal for compensation.

[0127] Thus, the objective of this invention has been achieved.

[0128] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-channel servo actuation system, characterized in that, include: A servo assembly, comprising at least two servos, each equipped with a servo sensor for detecting the corresponding servo's travel distance; The control mechanism is equipped with a control mechanism sensor to detect the rotational motion generated by the control mechanism during the driving process, and the rotational motion characterizes the motion synchronization error between each servo motor; The servo controller is configured as follows: Receive control commands from the flight control system; The detection data of each servo motor sensor and the detection data of the control mechanism sensor are collected simultaneously. Based on the control commands, data from each servo motor sensor, and data from the control mechanism sensor, a comprehensive calculation is performed to generate compensation control signals for each servo motor. The compensation control signal is sent to the corresponding servo motor to coordinate the movement of each servo motor, reduce the motion synchronization error, and make the servo motor output consistent with the control command.

2. The multi-channel servo actuation system according to claim 1, characterized in that, The servo motor is the actuator of the servo actuation system. Depending on its energy type and control components, it can be selected from one or more of the following actuators: electro-hydraulic servo valve actuator, direct drive valve actuator, electro-hydraulic actuator, and electromechanical actuator.

3. The multi-channel servo actuation system according to claim 1, characterized in that, The control mechanism is used to control the propeller pitch angle of the aircraft. Its motion includes linear motion along its own central axis and rotational motion about an axis perpendicular to the central axis. The rotational motion is caused by inconsistent motion of each servo motor and serves as the object of motion synchronization error detection.

4. The multi-channel servo actuation system according to claim 1, characterized in that, The servo sensor detects the servo's output stroke and feeds it back to the servo controller. Its detection error is proportional to the servo's extension amount, and the detection accuracy is worst when the servo is at its limit stroke position. The stroke errors of each servo are superimposed at the control mechanism, which aggravates the rotational motion.

5. The multi-channel servo actuation system according to claim 1, characterized in that, The control mechanism sensor is positioned to effectively detect the synchronization error of each servo motor and maintain high precision throughout the entire range of motion. The types of physical quantities detected by the control mechanism sensor include angle, length, strain, or stress, and its detection accuracy is higher than that of the servo motor sensor.

6. The multi-channel servo actuation system according to claim 1, characterized in that, The servo controller includes: A single-channel servo control module is used for independent closed-loop control of a single servo motor; The synchronization controller is used to perform closed-loop control based on the motion synchronization error signal detected by the control mechanism sensors, and to generate compensation signals for coordinating the movement of each servo motor. A weighted allocator is used to distribute the compensation signal to each servo motor according to a preset weight. The amplitude limiting module is used to limit the compensation signals distributed to each servo motor to prevent control failure due to system malfunctions.

7. The multi-channel servo actuation system according to claim 6, characterized in that, The weight allocator uses either a fixed weight allocation coefficient or a dynamic weight allocation coefficient. The dynamic weight allocation coefficient is dynamically adjusted based on at least one of the following factors: static characteristics, dynamic characteristics, and real-time operating status of each servo motor.

8. The multi-channel servo actuation system according to claim 6, characterized in that, The single-channel servo control module employs a PID control algorithm. The synchronization controller uses a PID control algorithm to perform closed-loop adjustment of motion synchronization error.

9. A synchronous control method for a multi-channel servo actuation system as described in any one of claims 1-8, characterized in that, Includes the following steps: Receive control commands issued by the flight control system and distribute the control commands to the control channels corresponding to each servo motor; Each control channel generates a single-channel control signal based on the received control command and the feedback signal of the corresponding servo motor, driving the corresponding servo motor to move, thus realizing single-channel closed-loop control; Each servo motor drives the control mechanism together; the control mechanism's rotational motion caused by inconsistent movements of each servo motor is detected by the control mechanism's sensors and used as a motion synchronization error signal. The motion synchronization error signal is input into the synchronization controller for closed-loop processing to generate a global compensation signal. The global compensation signal is distributed to each servo motor according to a preset weight by a weight allocator, thereby generating a channel compensation signal for each servo motor. After the compensation signals of each channel are amplitude-limited, they are superimposed on the original control command of the corresponding servo motor to correct the servo motor movement and reduce the motion synchronization error between the servo motors.

10. The synchronization control method according to claim 9, characterized in that, In the step of distributing the global compensation signal to each servo according to the preset weight, the weight is set by a fixed proportional coefficient or dynamically adjusted according to the performance parameters, real-time status and system preset strategy of each servo. In the step of inputting the motion synchronization error signal into the synchronization controller for closed-loop processing, the PID control algorithm is used to adjust the motion synchronization error in a closed loop. The amplitude limiting process is used to limit the amplitude of the compensation signal of each channel to prevent instability or damage caused by control system failure.

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