A hatch door control method and hatch door hydraulic system based on gravity moment compensation

Abstract

The present invention discloses a hatch door control method and hatch door hydraulic system based on gravity moment compensation. The control method includes real-time calculation of the hatch door gravity moment; compensating the control system based on the hatch door gravity moment to obtain a compensated control input; and controlling the hatch door to open, close, or maintain its current state based on the compensated control input. The present invention can improve the control accuracy of hatch door actuation.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft cabin door control systems, and in particular to a cabin door control method based on gravity moment compensation and a cabin door hydraulic system. Background Art

[0002] Aircraft doors are crucial components for ensuring mission success. During flight, the aircraft's attitude and aerodynamic loads constantly change, requiring precise door position control within a limited timeframe to avoid radar detection. New-generation fighter jets feature stealth, high maneuverability and agility, and supersonic cruise capabilities. During supersonic flight, the precise and rapid opening and closing of doors in complex and changing environments is crucial. The performance of door control methods directly impacts the aircraft's combat and technical specifications, significantly impacting combat performance.

[0003] In the prior art, the influence of gravity torque is generally not considered in aircraft cabin door hydraulic control systems, such as the aircraft cabin door hydraulic control mechanism disclosed in publication number CN111395906A. In actual applications, aircraft cabin doors are very heavy, and during the opening and closing process, as the cabin door angle changes, a large gravity torque is generated. The generation of this gravity torque will affect the accuracy of the cabin door control system. The control methods of the prior art do not consider the impact of the cabin door gravity torque on control accuracy, which to a certain extent limits the improvement of aircraft cabin door control performance. Traditional aircraft cabin door control systems, when using PID controllers for cabin door opening and closing control, do not consider the impact of gravity torque on the cabin door opening and closing process, and ignore the influence of gravity torque when generating the driving torque.

[0004] In summary, how to further improve the control accuracy of hatch door drive is one of the important issues that need to be urgently addressed in this field. Summary of the Invention

[0005] The purpose of the present invention is to provide a hatch door control method and a hatch door hydraulic system based on gravity moment compensation to address the deficiencies in the prior art, and it is possible to improve the control accuracy of the hatch door drive.

[0006] The present invention provides a hatch door control method based on gravity moment compensation, which includes:

[0007] Real-time calculation of hatch door gravity moment;

[0008] Compensating the control system according to the door gravity moment and obtaining the compensated control input;

[0009] Press the compensated control input to control the hatch to open, close or maintain the current state.

[0010] The hatch door control method based on gravity moment compensation as described above, wherein, optionally, the model adopted by the control system includes a servo valve flow equation, a hatch door hydraulic motor flow continuity equation, and a force balance equation;

[0011] Among them, the hatch gravity moment is used as an item in the force balance equation to achieve gravity moment compensation.

[0012] In the hatch door control method based on gravity moment compensation as described above, optionally, the force balance equation between the hatch door hydraulic motor and the load is:

[0013]

[0014] Among them, J t B is the total inertia of the motor output shaft and the total inertia converted to the output shaft. p is the viscous damping coefficient, K is the load elastic stiffness, T l is the load moment other than the door gravity moment, G(θ w ) is the door gravity moment, and θ is the hydraulic motor rotation angle.

[0015] In the hatch door control method based on gravity moment compensation as described above, optionally, the control input formula after compensation is:

[0016]

[0017] Where u is the control input, β e is the effective bulk elastic modulus, K q is the flow gain, K i is the proportional coefficient, k3 is the constant coefficient, z3 is the control error of the state variable x3, D m is the displacement of the hydraulic motor, x2 and x3 are both state variables, K c is the pressure gain, C tp is the total leakage coefficient of the hydraulic motor, V t is the total compression volume, and α2 is the virtual control of the state variable x3.

[0018] In the hatch door control method based on gravity moment compensation as described above, optionally, the servo valve flow equation is:

[0019] q L =K q x v -K c p L ;

[0020] Among them, q L is the load flow, K q is the flow gain, K c is the pressure gain, x vis the servo valve spool displacement, p L is the load pressure.

[0021] In the hatch door control method based on gravity moment compensation as described above, optionally, the flow continuity equation of the hatch door hydraulic motor is:

[0022]

[0023] Among them, D m is the displacement of the hydraulic motor, θ is the rotation angle of the hydraulic motor, C tp is the total leakage coefficient of the hydraulic motor, V t is the total compression volume, β e is the effective bulk elastic modulus.

[0024] In the above-mentioned hatch door control method based on gravity moment compensation, optionally, the formula for the hatch door gravity moment is:

[0025]

[0026] Among them, sgn() is the symbol function, is the desired door angular velocity, M is the door mass, g is the acceleration due to gravity, l is the door dimension perpendicular to its axis of rotation, and θ w The hatch opening angle.

[0027] The hatch door control method based on gravity moment compensation as described above, wherein, optionally, the control system includes a gravity moment compensation controller;

[0028] The gravity moment compensation controller obtains the expected value of the parameter and the actual detection value of the state variable;

[0029] The gravity moment compensation controller is used to calculate the cabin door gravity moment in real time according to the actual detection value, and calculate and output the control input according to the parameter expected value as the state variable, the actual detection value and the cabin door gravity moment.

[0030] The hatch control method based on gravity moment compensation as described above, wherein, optionally, the state variable is

[0031] Where θ is the door angle, p L is the load pressure.

[0032] The present invention also proposes a hatch door hydraulic system for use in any of the above methods; the hydraulic system comprises an onboard high-pressure oil source, an onboard oil tank, a three-position four-way solenoid valve, a hydraulic motor, a gravity moment compensation controller, and a sensor;

[0033] The onboard high-pressure oil source, the onboard oil tank, the inlet of the hydraulic motor, and the outlet of the hydraulic motor are respectively connected to the four ports of the three-position four-way solenoid valve through hydraulic pipelines;

[0034] The sensor is used to obtain the state parameters of the hydraulic system, and the three-position four-way solenoid valve and the sensor are both electrically connected to the gravity compensation controller;

[0035] The gravity compensation controller is used to obtain the expected parameter values and the detection results of the sensor, and calculate the cabin door gravity moment in real time; the gravity compensation controller is also used to calculate and output the control input based on the cabin door gravity moment, the expected parameter values and the detection results of the sensor.

[0036] Compared to existing technologies, the control method proposed in this invention considers the impact of gravity torque interference on the control process during door control. This allows for real-time compensation for the effects of gravity torque during door opening and closing, further improving the accuracy of door position control. By accounting for the impact of gravity torque interference during aircraft door actuation and providing real-time compensation, the dynamic and static performance of the aircraft door closed-loop system can be improved, enabling precise and rapid door opening and closing in complex and changing environments, thereby enhancing flight performance.

[0037] Compared with traditional PID control, it can completely eliminate the influence of interference torque and react more quickly than the integral link of PID control. By calculating the different gravity torque interferences corresponding to different angles, the gravity torque term G(θ w ) and compensate for the door gravity torque interference in the control input to improve the speed, accuracy and stability of the door position control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of the steps of the hatch door control method based on gravity moment compensation proposed by the present invention;

[0039] Figure 2 This is the control block diagram of the hatch system;

[0040] Figure 3 The force analysis diagram of the hatch in different states;

[0041] Figure 4 This is a structural block diagram of the hatch door hydraulic system proposed in the present invention.

[0042] Description of reference numerals:

[0043] 1-three-position four-way solenoid valve, 2-hydraulic motor, 3-gravity torque compensation controller, 4-sensor. DETAILED DESCRIPTION

[0044] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention.

[0045] Typically, hatch door control utilizes the PID control principle. This feedback control method boasts a simple algorithm and minimal computational effort. However, due to factors such as the hatch's complex operating environment and the influence of gravity torque interference, this method is relatively crude and approximate. This drawback is particularly pronounced when the hatch is in rapid motion.

[0046] That is, although the PID control input can adjust the system's static error to zero through the integral phase, suppressing the generated interference torque, the integral phase generally works relatively slowly and cannot completely eliminate the influence of the interference torque. If the control input can compensate for the interference torque, it would be a more ideal control strategy. The present invention proposes a hatch door control strategy based on gravity torque compensation through the following implementation.

[0047] Example 1

[0048] Please refer to Figures 1 to 3 This embodiment proposes a hatch door control method based on gravity moment compensation, which includes, S1, real-time calculation of the hatch door gravity moment. Specifically, the hatch door gravity moment is related to the hatch door opening angle. That is, the gravity moment has a significant impact on the hatch door actuation process. The magnitude of the hatch door gravity moment can be obtained based on the dynamic equation relationship. During the hatch opening process, when θ is an acute angle, the interference component is 0.5Mglcosθ w >0; when θ=0°, the interference component is 0.5Mgl, when θ=90°, the interference component is 0; when θ is an obtuse angle, the interference component is 0.5Mglcosθ w <0. The sign of the gravity moment in the closing process is opposite to that in the opening process. The gravity moments in the opening and closing processes are expressed uniformly as Among them, sgn() is the sign function, is the desired door angular velocity, M is the door mass, g is the acceleration due to gravity, l is the door dimension perpendicular to its axis of rotation, and θ w The hatch opening angle.

[0049] S2 compensates the control system according to the hatch door gravity moment and obtains the compensated control input. By calculating the different gravity moments corresponding to different angles, the gravity moment term G(θ) is added to the model, and the hatch door gravity moment interference is compensated in the control input to improve the speed, accuracy and stability of the hatch door position control system.

[0050] S3, according to the compensated control input, controls the hatch to open, close or maintain the current state.

[0051] That is, by considering the impact of gravity torque interference during the actuation of the aircraft door and compensating for it in real time, the dynamic and static performance of the aircraft door closed-loop system can be improved, allowing the aircraft door to open and close accurately and quickly in complex and changing environments, thereby improving flight performance.

[0052] In specific implementation, the model adopted by the control system includes the servo valve flow equation, the hatch hydraulic motor flow continuity equation and the force balance equation; among them, the hatch gravity moment is used as an item in the force balance equation to achieve gravity moment compensation.

[0053] More specifically, in order to implement the above control process,

[0054] Establish the hatch dynamics model and servo valve flow equation:

[0055] q L =K q x v -K c p L ;

[0056] Where q L is the load flow, K q is the flow gain, K c is the pressure gain, x v is the servo valve spool displacement, p L is the load pressure.

[0057] The response frequency of the servo valve is much larger than the natural frequency of the system and can be regarded as a proportional link:

[0058] x v =K i u;

[0059] Where x v is the servo valve spool displacement, K i is the proportional coefficient and u is the control input.

[0060] The flow continuity equation of the hatch hydraulic motor is:

[0061]

[0062] Among them, q L is the load flow, D m is the displacement of the hydraulic motor, θ is the rotation angle of the hydraulic motor, C tp is the total leakage coefficient of the hydraulic motor, V t is the total compression volume, β e is the effective bulk modulus, p L is the load pressure.

[0063] The hatch hydraulic motor is affected by complex interference torques during operation. Since the gravity torque has a great influence and is the dominant interference, the gravity torque interference is taken into account in the model here.

[0064] The force balance equation between the hatch hydraulic motor and the load is:

[0065]

[0066] Among them, D m is the hydraulic motor displacement, p L is the load pressure, J t B is the total inertia of the motor output shaft and the total inertia converted to the output shaft. p is the viscous damping coefficient, K is the load elastic stiffness, T l is the load moment other than the door gravity moment, G(θ w ) is the door gravity moment, and θ is the hydraulic motor rotation angle.

[0067] Performing Laplace transform on the system equations yields:

[0068] X v =K i U

[0069] Q L =K q X v -K c P L

[0070]

[0071] D m P L =J t s 2 θ+B p sθ+Kθ+T l -G(θ w )

[0072] Among them, X v is the servo valve spool displacement in the frequency domain, U is the control input in the frequency domain, Q L is the load flow in the frequency domain, P L is the load pressure in the frequency domain, and s is the complex frequency variable.

[0073] The hatch system control block diagram is obtained from the above formula as follows: Figure 2 As shown, it can be seen that the movement of the hatch is affected by the interfering gravitational moment.

[0074] The gravity moment analysis of the hatch is as follows: Figure 3As shown in the figure, different angles correspond to different gravity torque interferences. Since the law of gravity torque interference in the dynamic equation is available, and the gravity torque has a significant impact on the control effect during the door actuation process, it is necessary to compensate for the gravity torque through certain methods.

[0075] During the opening process, when θ is an acute angle, the interference component is 0.5Mglcosθ w >0; when θ=0°, the interference component is 0.5Mgl, when θ=90°, the interference component is 0; when θ is an obtuse angle, the interference component is 0.5Mglcosθ w <0. The sign of the hatch closing process is opposite to that of the hatch opening process.

[0076] Through the above analysis, the gravity moment interference is the angle θ w The posture function is not affected by the time parameter. The gravity moment of the hatch door during the opening and closing process is uniformly expressed as G(θ w ), calculate the gravity moment in real time and compensate for it:

[0077]

[0078] Where sgn() is the sign function, is the desired door angular velocity.

[0079] Select state variables Through the above analysis, the hatch system can be written in the form of state equation:

[0080]

[0081]

[0082]

[0083] The control input formula after compensation is:

[0084]

[0085] Where u is the control input, β e is the effective bulk elastic modulus, K q is the flow gain, K i is the proportional coefficient, k3 is the constant coefficient, z3 is the control error of the state variable x3, D m is the displacement of the hydraulic motor, x2 and x3 are both state variables, K c is the pressure gain, C tp is the total leakage coefficient of the hydraulic motor, V t is the total compression volume, and α2 is the virtual control of the state variable x3.

[0086] The control system includes a gravity moment compensation controller;

[0087] The gravity moment compensation controller obtains the expected value of the parameter and the actual detection value of the state variable;

[0088] The gravity moment compensation controller is used to calculate the cabin door gravity moment in real time according to the actual detection value, and calculate and output the control input according to the parameter expected value as the state variable, the actual detection value and the cabin door gravity moment.

[0089] The acquisition of control input can be achieved through the inverse control method, which can be achieved by following the steps below:

[0090] The first step is to expect the hydraulic motor angle to be x d =θ d , define the control error z1:

[0091] z1=x1-x d ;

[0092] Define the first Lyapunov function V1 as:

[0093]

[0094] Taking the derivative we get:

[0095]

[0096] Design a virtual control α1 for x2 and define the control error z2: z2 = x2 - α1;

[0097] So we can get:

[0098]

[0099] According to the above formula, the control variable α1 of x2 is selected as:

[0100]

[0101] Then we have:

[0102]

[0103] The second step is to find the derivative of z2:

[0104]

[0105] Define the second Lyapunov function V2 as:

[0106]

[0107] Then we have:

[0108]

[0109] Design a virtual control α2 for x3 and define the control error z3: z3=x3-α2;

[0110] So we can get:

[0111]

[0112] According to the above formula, the control variable α2 of x3 is selected as:

[0113]

[0114] Then we have:

[0115]

[0116] The third step is to find the derivative of z3:

[0117]

[0118] Define the third Lyapunov function V3 as:

[0119]

[0120] Then we have:

[0121]

[0122] The final control rate u can be obtained:

[0123]

[0124] Substituting the designed control input u into the derivative of V3, we can obtain:

[0125]

[0126] At this point, the design of the control input u is complete, and the stability of the control input has been proven. In other words, the above control method can significantly improve the dynamic and static characteristics and robustness of the aircraft cabin door closed-loop system.

[0127] Example 2

[0128] This embodiment proposes a hatch hydraulic system for the method described in Example 1. The same and corresponding parts are repeated, and only the differences are described below.

[0129] Please refer to Figure 4The hydraulic system includes an onboard high-pressure oil source, an onboard oil tank, a three-position four-way solenoid valve 1, a hydraulic motor 2, a gravity torque compensation controller 3 and a sensor 4. In specific implementation, the type and quantity of the sensors 4 are multiple, which are determined according to the actual state parameters to be detected. For example, it can include an angle sensor for detecting the door opening and a pressure sensor for detecting the load pressure.

[0130] The onboard high-pressure oil source, the onboard oil tank, the inlet of the hydraulic motor 2 , and the outlet of the hydraulic motor 2 are respectively connected to the four ports of the three-position four-way solenoid valve 1 through hydraulic pipelines.

[0131] The sensor 4 is used to obtain the state parameters of the hydraulic system. The three-position four-way solenoid valve 1 and the sensor 4 are both electrically connected to the gravity compensation controller.

[0132] The gravity compensation controller is configured to obtain the expected parameter values and the detection results of the sensor 4 and calculate the door gravity moment in real time. The gravity compensation controller is further configured to calculate and output a control input based on the door gravity moment, the expected parameter values, and the detection results of the sensor 4. Specifically, the calculation process of the control input is similar to that of Example 1.

[0133] Through the above-described Examples 1 and 2, the present invention considers the impact of gravity torque interference on the control process during door control, enabling real-time compensation for the effects of gravity torque during door opening and closing, further improving the accuracy of door position control. By considering the impact of gravity torque interference during aircraft door actuation and compensating for gravity torque interference in real time, the dynamic and static performance of the aircraft door closed-loop system can be improved, enabling precise and rapid opening and closing of aircraft doors in complex and changing environments, thereby enhancing flight performance.

[0134] Compared with traditional PID control, it can completely eliminate the influence of interference torque and react more quickly than the integral link of PID control. By calculating the different gravity torque interferences corresponding to different angles, the gravity torque term G(θ w ) and compensate for the door gravity torque interference in the control input to improve the speed, accuracy and stability of the door position control system.

[0135] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present invention, but the scope of implementation of the present invention is not limited to what is shown in the drawings. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present invention.

Claims

1. A hatch door control method based on gravity moment compensation, characterized by: include, Real-time calculation of hatch door gravity moment; Compensating the control system according to the door gravity moment and obtaining the compensated control input; According to the compensated control input, the hatch door is controlled to open, close or maintain the current state; The model used in the control system includes the servo valve flow equation, the hatch hydraulic motor flow continuity equation and the force balance equation; Among them, the hatch gravity moment is used as a term in the force balance equation to achieve gravity moment compensation; The force balance equation is: ； in, is the motor output shaft and the total inertia converted to the output shaft, is the viscous damping coefficient, is the load elastic stiffness, is the load moment other than the door gravity moment, is the door gravity moment, is the hydraulic motor rotation angle; is the load pressure, is the hydraulic motor displacement; The control input formula after compensation is: ； in, is the control input, is the effective bulk modulus, is the flow gain, is the proportionality coefficient, is a constant coefficient, is a state variable The control error, is the hydraulic motor displacement, and are all state variables, is the pressure gain, is the total leakage coefficient of the hydraulic motor, is the total compression volume, is a state variable Virtual control.

2. The hatch door control method based on gravity moment compensation according to claim 1, characterized in that: The servo valve flow equation is: ； in, is the load flow, is the flow gain, is the pressure gain, is the servo valve spool displacement, is the load pressure.

3. The hatch door control method based on gravity moment compensation according to claim 1, characterized in that: The flow continuity equation of the hatch hydraulic motor is: ； in, is the load flow, is the hydraulic motor displacement, is the hydraulic motor angle, is the total leakage coefficient of the hydraulic motor, is the total compression volume, is the effective bulk modulus, is the load pressure.

4. The hatch door control method based on gravity moment compensation according to any one of claims 1 to 3, characterized in that: The formula for the door gravity moment is: ； in, is a symbolic function, is the desired door angular velocity, is the mass of the hatch, g is the acceleration due to gravity, is the dimension of the door perpendicular to its rotation axis, The hatch opening angle.

5. The hatch door control method based on gravity moment compensation according to any one of claims 1 to 3, characterized in that: The control system includes a gravity moment compensation controller; The gravity moment compensation controller obtains the expected value of the parameter and the actual detection value of the state variable; The gravity moment compensation controller is used to calculate the cabin door gravity moment in real time according to the actual detection value, and calculate and output the control input according to the parameter expected value as the state variable, the actual detection value and the cabin door gravity moment.

6. The hatch door control method based on gravity moment compensation according to claim 5, characterized in that: The state variables are ; in, is the hydraulic motor rotation angle, is the load pressure.

7. A hatch door hydraulic system, characterized by: Used in the method according to any one of claims 1 to 6; the hydraulic system includes an onboard high-pressure oil source, an onboard oil tank, a three-position four-way solenoid valve, a hydraulic motor, a gravity moment compensation controller and a sensor; The onboard high-pressure oil source, the onboard oil tank, the inlet of the hydraulic motor, and the outlet of the hydraulic motor are respectively connected to the four ports of the three-position four-way solenoid valve through hydraulic pipelines; The sensor is used to obtain the state parameters of the hydraulic system, and the three-position four-way solenoid valve and the sensor are both electrically connected to the gravity moment compensation controller; The gravity moment compensation controller is used to obtain the expected parameter values and the detection results of the sensor, and calculate the cabin door gravity moment in real time; the gravity moment compensation controller is also used to calculate and output the control input based on the cabin door gravity moment, the expected parameter values and the detection results of the sensor.

Images