A three-dimensional attitude control system composed of multiple reaction wheels and a control method thereof

Abstract

The application discloses a three-dimensional attitude control system composed of multiple reaction wheels and a control method thereof, and belongs to the technical field of attitude control. The three-dimensional attitude control system composed of multiple reaction wheels comprises an attitude control processor composed of three reaction wheel groups, the reaction wheel group comprises a base plate, a microprocessor, an electric governor controller, a motor and an inertial sensor mounted on the base plate, a mass wheel is mounted at the output end of the motor, the inertial sensor and the electric governor controller are connected with the microprocessor and are used for signal processing and equipment control, the microprocessor is connected with the attitude control processor and is used for data exchange control and coordination, and the application is applied to a vehicle body or the like. The application not only can provide higher attitude judgment adjustment sensitivity and timeliness, but also can improve the body load, reduce unnecessary body weight and prolong the service life of the body.

Description

Technical Field

[0001] This invention relates to the field of attitude control technology, and in particular to a three-dimensional attitude control system and control method consisting of multiple reaction wheels. Background Technology

[0002] In many applications, adequate control over the orientation or attitude of a vehicle is crucial. After the vehicle's orientation is sensed, actuators are commanded to apply torque to reorient the vehicle to the desired attitude. In space, most spacecraft utilize active control techniques employing different types of attitude control methods, depending on the specific maneuver to be performed and the requirements. The most common method for orienting spacecraft in space is to define orbits that the spacecraft can follow to achieve the desired orientation, apply these predefined orbits, and linearize the system for each appropriate operating point.

[0003] Spacecraft, including satellites, space stations, space shuttles, and spaceships, require propellant to function through their attitude nozzles. However, propellant takes up payload space and weight, thus reducing the volume and weight of the operational payload. Furthermore, spacecraft are limited by the amount of propellant they can carry; once the propellant is used up, they lose the ability to change their attitude, resulting in unnecessary weight or material waste.

[0004] In addition, for high-speed underwater vehicles such as torpedoes and submarines, attitude changes are mostly achieved by using stern control surfaces. Under high-speed conditions, the control surfaces are subjected to large forces, and moving parts are easily damaged. Furthermore, the center of gravity is at the stern, resulting in a large radius of attitude change and poor flexibility. Therefore, we propose to achieve convenient attitude control of the vehicle by using a gyroscope composed of multiple reaction wheels. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies in which the attitude of transportation vehicles is limited and lacks flexibility. This invention proposes a three-dimensional attitude control system and its control method consisting of multiple reaction wheels.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A three-dimensional attitude control system consisting of multiple reaction wheels includes three sets of reaction wheel groups, namely reaction wheel group A, reaction wheel group B and reaction wheel group C, and an attitude control processor for main adjustments. Each set of reaction wheel groups includes a base plate, a microprocessor, an electronic speed controller, and a motor and an inertial sensor mounted on the base plate. A mass wheel is mounted on the output end of the motor. The inertial sensor and the electronic speed controller are connected to the microprocessor for signal processing and equipment control. The microprocessor is connected to the attitude control processor for data exchange and control coordination.

[0008] To improve the sensitivity of the reaction wheel, preferably, two sets of inertial sensors are provided and symmetrically arranged on the substrate. When arranging them, it is advisable to arrange them symmetrically with the diagonal of the substrate as the axis, as their detection sensitivity is much higher than that of symmetrical arrangement on one side of the substrate.

[0009] Preferably, the mass wheel includes a counterweight ring and a mounting post, the mounting post being fixedly mounted at the output end of the motor, and the counterweight ring being connected to the mounting post via a connecting rod.

[0010] To ensure stable strength when the mass wheel rotates at high speed, the connecting rod is further provided in four sets, and the four sets of connecting rods are evenly distributed in a circle on the mounting column.

[0011] To enhance the working centrifugal force of the mass wheel, preferably, the mass wheel further includes a base plate and an auxiliary plate, the base plate being fixedly mounted at the output end of the motor, and a transition surface being provided between the base plate and the auxiliary plate.

[0012] Furthermore, the thickness of the auxiliary disk is greater than the thickness of the base disk.

[0013] A control method for a three-dimensional attitude control system consisting of multiple reaction wheels includes the following steps:

[0014] S1: Measure the inertia data of each reaction wheel assembly, including acceleration and tilt angle, using inertial sensors;

[0015] S2: Calculate the motion vectors of the near-end inertial sensor and the far-end inertial sensor respectively based on the measured values;

[0016] S3: Based on the attitude control requirements, the direction and speed of the motor rotation are controlled by the electronic speed controller. The motor drives the mass wheel to rotate, thereby adjusting the direction and magnitude of the motion vector of the reaction wheel assembly.

[0017] S4: Compare the vectors of the near-end inertial sensor and the far-end inertial sensor. When the motion vectors converge, the attitude change is small. When the motion vectors are different, the attitude change is larger, thereby achieving attitude control.

[0018] A spacecraft comprising a three-dimensional attitude control system consisting of multiple reaction wheels.

[0019] An underwater vehicle includes a three-dimensional attitude control system consisting of multiple reaction wheels.

[0020] Compared with the prior art, the present invention provides a three-dimensional attitude control system and its control method composed of multiple reaction wheels, which has the following beneficial effects:

[0021] 1. The three-dimensional attitude control system and its control method, which consists of multiple reaction wheels, can eliminate or reduce the carrying of attitude control propellant when applied to spacecraft, thereby improving the payload carrying capacity, and the attitude control algorithm is simpler.

[0022] 2. When the three-dimensional attitude control system and its control method, which consists of multiple reaction wheels, are applied to underwater vehicles, the control surfaces can be eliminated on the outer surface to reduce frictional resistance and avoid control surface failure; the center of gravity of attitude control is shifted to the midships; the attitude adjustment radius is reduced, and attitude adjustment is more flexible.

[0023] The parts of this device not covered herein are the same as or can be implemented using existing technologies. When applied to aircraft such as spacecraft, this invention can not only provide more efficient attitude judgment and adjustment sensitivity and timeliness, but also increase the load on the aircraft, reduce unnecessary weight on the aircraft, and extend the service life of the aircraft. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a three-dimensional attitude control system composed of multiple reaction wheels proposed in this invention. Figure 1 ;

[0025] Figure 2 This is a schematic diagram of the mass wheel proposed in this invention. Figure 1 ;

[0026] Figure 3 This is a schematic diagram of the mass wheel proposed in this invention. Figure 2 ;

[0027] Figure 4 This is a schematic diagram of the structure of a three-dimensional attitude control system composed of multiple reaction wheels proposed in this invention. Figure 2 ;

[0028] Figure 5 This is a schematic diagram of the structure proposed in this invention. Figure 1 ;

[0029] Figure 6 This is a schematic diagram of the structure proposed in this invention. Figure 2 .

[0030] In the figure: 1. Base plate; 2. Inertial sensor; 3. Motor; 4. Counterweight ring; 401. Mounting post; 402. Connecting rod; 5. Base plate; 501. Transition surface; 502. Auxiliary plate. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0032] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] Example 1

[0034] Reference Figure 1 and Figure 2 A three-dimensional attitude control system composed of multiple reaction wheels includes three reaction wheel groups: reaction wheel group A, reaction wheel group B, and reaction wheel group C, and an attitude control processor for main adjustments. Each reaction wheel group includes a base plate 1, a microprocessor, an electronic speed controller, a motor 3 mounted on the base plate 1, and two sets of inertial sensors 2. Reaction wheel groups A, B, and C are arranged as three adjacent faces of a cube, forming a reaction wheel gyroscope. Each reaction wheel group corresponds to a positive axis of the coordinate system using the right-hand rule. Individual reaction wheels achieve their own stability based on the principle of gyroscopes. The attitude control processor controls each reaction wheel group. Rotation speed and direction are controlled to form a dynamically balanced whole, achieving a stable angular attitude of the system. The right-hand rule typically defines the axis as positive, the reaction wheel rotates along the bending direction of the four fingers (index finger, etc.), and the thumb points towards the positive axis. Two sets of inertial sensors 2 are symmetrically arranged on the base plate 1. It is advisable to arrange them symmetrically with the diagonal of the base plate as the axis, as their detection sensitivity is much higher than that of symmetrical arrangement on one side of the base plate. A mass wheel is installed at the output end of the motor 3. The inertial sensors 2 and the electronic speed controller are connected to the microprocessor via the CAN bus protocol for signal processing and equipment control. The microprocessor is connected to the attitude control processor for data exchange and control coordination.

[0035] The mass wheel is configured as a combination of a hollow counterweight ring 4 and a mounting post 401, ensuring that the center of the mounting post 401 is fixedly set at the output end of the motor 3. The counterweight ring 4 is connected to the mounting post 401 through connecting rods 402 to form multiple hollow structures. There are four sets of connecting rods 402, and the four sets of connecting rods 402 are evenly distributed on the mounting post 401 in a circle. Thus, the flexibility of the mass wheel can be improved while ensuring manufacturing costs.

[0036] Example 2

[0037] Reference Figure 1 and Figure 3Similar to Embodiment 1, but further, in order to be suitable for large equipment and control applications requiring rapid response and adjustment, the mass wheel is replaced with a solid base plate 5 and an auxiliary plate 502. The base plate 5 is fixedly installed at the output end of the motor 3, and the thickness of the auxiliary plate 502 is greater than that of the base plate 5. The base plate 5 and the auxiliary plate 502 are connected and transitioned through an inclined transition surface 501 to ensure the strength of the connection and the overall rigidity of the mass wheel.

[0038] Example 3

[0039] Reference Figure 3 and Figure 4 The attitude adjustment process includes yaw angle, roll angle and pitch angle;

[0040] First, establish a three-dimensional coordinate system, assuming the Y-axis is the heading, the X-axis is the starboard side, and the Z-axis is the vertical direction.

[0041] When a three-dimensional coordinate system is applied to a submersible or spacecraft, the bow direction is taken as the positive Y-axis, the starboard side as the positive X-axis, and the Z-axis is perpendicular to the Y-axis and pointing upwards. This system can represent the vehicle's attitude during operation.

[0042] Pitch angle, the angle between the aircraft's longitudinal axis and the horizontal plane, i.e., the angle between Z and Y. The adjustment of the pitch angle is as follows:

[0043] First, the bow adjusts the X-axis speed while keeping the Y-axis and Z-axis speeds unchanged. Second, the stern adjusts the X-axis speed in the opposite direction to the bow while keeping the Y-axis and Z-axis speeds unchanged. Finally, the midships adjusts the X-axis speed to coordinate the steering rate and adjust the Y-axis and Z-axis speeds to balance external perturbations, thereby generating X-axis torque.

[0044] Yaw angle is the angle between the projection of the aircraft's longitudinal axis onto the horizontal plane and the parameter line on that plane, i.e., the angle between Y and X. The adjustment of the yaw angle is as follows:

[0045] First, the Z-axis speed at the bow is adjusted while the X-axis and Y-axis speeds remain unchanged. Second, the Z-axis speed at the stern is adjusted in the opposite direction to that at the bow while the X-axis and Y-axis speeds remain unchanged. Finally, the Z-axis speed at the midships is adjusted to coordinate the steering rate and adjust the X-axis and Y-axis speeds to balance external perturbations, thereby generating Z-axis torque.

[0046] Roll angle is the angle between the aircraft's plane of symmetry and the vertical plane passing through the aircraft's longitudinal axis, the Z-angle and X-angle. The adjustment of the roll angle is as follows:

[0047] First, the bow adjusts the Y-axis speed while keeping the X and Z-axis speeds unchanged. Second, the stern adjusts the Y-axis speed in the opposite direction to the bow while keeping the X and Z-axis speeds unchanged. Finally, the midships adjusts the Y-axis speed to coordinate the steering rate and adjust the X and Z-axis speeds to balance external perturbations, thereby generating Y-axis torque.

[0048] When performing attitude control on vehicles such as submarines and spacecraft, three reaction wheel gyroscopes are required to work together. The three gyroscopes are installed at the bow, midships, and stern of the vehicle, respectively. The bow controls the vehicle's center of gravity, the stern provides auxiliary center of gravity control, and the vehicle can perform attitude control with the stern or midships as the center. The midships are responsible for canceling attitude control errors and coordinating attitude control between the bow and stern.

[0049] Reference Figure 5 For example, changing course to the right:

[0050] 1. The bow gyroscope changes the speed of the X-axis wheel, which can be used to increase or decrease the speed, or to stop the machine, depending on the system settings;

[0051] 2. The stern gyroscope changes the speed of the X-axis wheel in the opposite direction of the bow system's motion. Depending on the system settings, this can be used to increase or decrease the speed, or to enable emergency stop.

[0052] 3. The midships gyroscope coordinates the steering based on the input control commands, appropriately adjusting the speed of the X-axis wheel to offset the steering error of the aircraft caused by external factors.

[0053] Example 4

[0054] Given the existing three-dimensional attitude control system consisting of multiple reaction wheels, a control method for the system is developed, including the following steps:

[0055] S1: Measure the inertia data of each reaction wheel assembly, including acceleration and tilt angle, using inertial sensor 2;

[0056] S2: Calculate the motion vectors of the near-end inertial sensor 2 and the far-end inertial sensor 2 respectively based on the measured values;

[0057] S3: Based on the attitude control requirements, the direction and speed of the rotation of motor 3 are controlled by the electronic speed controller. Motor 3 drives the mass wheel to rotate, thereby adjusting the direction and magnitude of the motion vector of the reaction wheel group.

[0058] S4: Compare the vectors of the near-end inertial sensor 2 and the far-end inertial sensor 2. When the motion vectors converge, the attitude change amplitude is small. When the motion vectors are different, the attitude change amplitude increases, thereby achieving attitude control.

[0059] A spacecraft includes a three-dimensional attitude control system consisting of multiple reaction wheels. In practical use, it eliminates or reduces the carrying of attitude control propellant, improves payload carrying capacity, and simplifies the attitude control algorithm.

[0060] An underwater vehicle includes a three-dimensional attitude control system consisting of multiple reaction wheels. In practical use, the rudder surfaces on the outer facade are eliminated, which can reduce frictional resistance and avoid rudder failure; the center of gravity for attitude control is shifted to the midships; the attitude adjustment radius is reduced, and attitude adjustment is more flexible.

[0061] In this invention, the three-dimensional attitude control system and its control method are applicable to large aircraft and large-scale spacecraft. Using physical reaction wheel gyroscope systems in large aircraft presents problems such as excessive reaction wheel mass, large gyroscope size, and low gyroscope response speed. This method utilizes multiple small-sized, lightweight individual reaction wheel units distributed along the inscribed circle of the cross-section inside the aircraft. An algorithm is used to construct a virtual gyroscope system located at the center of the cross-section where the reaction wheels are positioned. The attitude control of the large aircraft is achieved based on the gyroscope system composed of these reaction wheels. Taking an eight-component virtual gyroscope as an example, each reaction wheel system is distributed with a 45° deviation on the cross-section. The attitude deflection of the virtual gyroscope is achieved by changing the relative position and rotational speed of the reaction wheels, thereby realizing the attitude control of the aircraft.

[0062] The oscillation angle of the reaction wheel is evaluated using Kalman filtering, and tilt estimation is performed based solely on two inertial sensors. This allows for a three-dimensional tilt estimation of the reaction wheel assembly. The two inertial sensors are placed diagonally along the mass wheel, at a distance r from the central axis. i With i=1 and i=2, two direction vectors can be obtained. , , Indicates the tangent of the mass wheel's rotation. Representing the axial and radial directions, each inertial sensor can be represented as follows:

[0063]

[0064] Dynamic items are represented as:

[0065] a1m − µa2m = ((1 − µ)g sin θb, −(1 − µ)g cos θb, 0),

[0066] =: (mx, my, 0),

[0067]

[0068] when The estimated tilt angle of the reaction wheel can be determined by...

[0069] Let the rotation based on the edge be {A} and the rotation based on the angle be {B}. The nonlinear dynamic formula for the reaction wheel assembly can be derived using the Kane equation, Jacobi determinant, etc. Treating the reaction wheel assembly as a rigid polyhedron, let the reaction wheels be... .

[0070] The time derivative of the linear momentum of the reaction wheel assembly angular velocity can be obtained:

[0071]

[0072] The Jacobian matrix related to the reaction wheel housing is represented as follows:

[0073]

[0074]

[0075] The Jacobian matrix related to the mass wheel of the reaction wheel assembly is expressed as follows:

[0076]

[0077]

[0078] The equation of motion for the reaction wheel assembly is:

[0079] (1)

[0080] The reaction wheel assembly is in equilibrium. It should meet the following requirements:

[0081] (2)

[0082] The angular velocity is 0, that is Inserting equation (1) into equation (2), we obtain the linearized expression for the equilibrium state:

[0083] (3)

[0084] in This indicates the deviation from the equilibrium value.

[0085] eliminate and We can obtain:

[0086]

[0087] (4)

[0088] It can be known

[0089]

[0090] The above formula derivation completes the Kalman filter derivation from the predicted state to the equilibrium state, thereby establishing the mathematical derivation of the reaction wheel group.

[0091] First, define the reaction wheel's own coordinate system and establish an edge rotation vector set A and an angular rotation vector set B, which serve as the basis for evaluating the reaction wheel's equilibrium state. First, define the direction of the counter-torque generated after the mass wheel rotates (the counter-torque is opposite to the direction of the mass wheel's rotation). Second, introduce the Kane equation to evaluate the influence of the torque generated by the motor's rotation driving the mass wheel on the changes in angular velocity in various directions. Third, introduce the Jacobi equation to estimate the momentum relationships over time. Next, incorporate error calculations, and finally perform vector calculations to obtain the describing equations based on the variables in the Kalman equations, thereby completing the linear calculation of the overall motion trend.

[0092] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A three-dimensional attitude control method composed of a plurality of reaction wheels, characterized by, The three groups of reaction wheel groups and the attitude control processor, the reaction wheel group comprises a substrate (1), a microprocessor, an electric controller, a motor (3) and an inertial sensor (2) mounted on the substrate (1), the output end of the motor (3) is provided with a mass wheel, the inertial sensor (2) and the electric controller are connected with the microprocessor for signal processing and equipment control, the microprocessor is connected with the attitude control processor for data exchange control and coordination, the inertial sensor (2) is provided with two groups, and the two groups are symmetrically arranged on the substrate (1); The mass wheel comprises a counterweight ring (4) and a mounting column (401), the mounting column (401) is fixedly arranged on the output end of the motor (3), the counterweight ring (4) is connected with the mounting column (401) through a connecting rod (402), the connecting rod (402) is provided with four groups, and the four groups of connecting rods (402) are uniformly distributed on the mounting column (401) in a circle; Or the mass wheel comprises a base disc (5) and an auxiliary disc (502), the base disc (5) is fixedly arranged on the output end of the motor (3), a transition surface (501) is arranged between the base disc (5) and the auxiliary disc (502), and the thickness of the auxiliary disc (502) is greater than that of the base disc (5); Further comprising the following steps: S1: measuring the inertia data of each reaction wheel group through the inertial sensor (2), including acceleration and inclination angle; S2: calculating the motion vectors of the proximal inertial sensor (2) and the distal inertial sensor (2) respectively according to the measured values; S3: according to the attitude control requirement, the direction and speed of the motor (3) are controlled through the electric controller, the motor (3) drives the mass wheel to rotate, and then the motion vector direction and size of the reaction wheel group are adjusted; S4: comparing the vectors of the proximal inertial sensor (2) and the distal inertial sensor (2), when the motion vectors are the same, the attitude change amplitude is small, and when the motion vectors are different, the attitude change amplitude is increased; S5: the motion vectors of the reaction wheel groups located at different positions of the aircraft are controlled, and then the attitude of the aircraft is controlled, the swing angle of the reaction wheel is evaluated based on Kalman filtering, the inclination estimation of only two inertia sensors is based on, and then three-dimensional inclination estimation of the reaction wheel group can be carried out, two inertia sensors are placed along the diagonal line of the mass wheel, first, define the reaction wheel coordinate system, set up the edge rotation vector set A and the angle rotation vector set B, which are used as the basis for evaluating the balance state of the reaction wheel, and the direction of the counter-torque generated after the rotation of the mass wheel is set, secondly, the Kane equation is introduced to evaluate the influence of the torque generated by the rotation of the motor on the change of the angular velocity in each direction, thirdly, the Jacobian equation is introduced to estimate the momentum relationship in time, then the error calculation is brought in, and finally the vector calculation is carried out to obtain the description equation of each variable in the Kalman equation, so as to complete the linear calculation of the overall motion trend.

2. A spacecraft, characterized by, The three-dimensional attitude control method comprising a plurality of reaction wheels according to claim 1.

3. An underwater vehicle, characterized by The three-dimensional attitude control method comprising a plurality of reaction wheels according to claim 1.

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