An integrated transport, erect and adaptive leveler for small spacecraft

Abstract

The application discloses a kind of transport, erecting and self-adaptive leveling integrated equipment for small spacecraft, including carrying chassis, erecting mechanism, self-adaptive leveling platform and intelligent control system.Carrying chassis is used to execute transport and parking locking;Intelligent control system is based on launch site surveying and mapping and ideal vertical attitude model, constructs optimal kinematics solution matrix;Data fed back by multidimensional inclination sensor are used to carry out forward reasoning, drive self-adaptive leveling platform to complete coarse leveling;In the process that spacecraft is erected to vertical state by erecting mechanism, based on control error function and PID algorithm closed loop adjustment platform parameter, dynamic accurate leveling is realized.The application solves the problems of low efficiency, easy to produce coupling interference and poor environmental adaptability of traditional split type equipment, realizes high-precision automatic collaborative control for complex field terrain, and greatly shortens the launch preparation period.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft ground support equipment technology, and specifically relates to an integrated equipment for the transportation, erection and adaptive leveling of small spacecraft. Background Technology

[0002] In recent years, the commercial space industry has developed rapidly, with the number of launches of microsatellites and small spacecraft continuously increasing, becoming an important development direction in the global space field. During the ground preparation phase before launch, small spacecraft require transfer from the assembly plant to the launch pad, attitude erection, and final precise leveling. Currently, traditional ground support equipment typically separates transportation, erection, and leveling functions, using independent transport vehicles, erection frames, and leveling bases. This split-operation mode requires multiple hoisting and handover operations between different equipment, which not only severely impacts launch preparation efficiency but also poses uncontrollable vibration and shock risks to the precision payloads inside the spacecraft.

[0003] Furthermore, traditional equipment suffers from poor environmental adaptability, low leveling accuracy, and insufficient system automation when used for non-standard launch sites or complex field terrain. Its leveling process often relies on manual intervention or semi-automatic mechanical adjustments, lacking research on adaptive sensing and active compensation mechanisms. This makes it impossible to guarantee the safety, stability, and high precision requirements of spacecraft erection and leveling under complex conditions. Specifically, erection equipment based on purely mechanical limits is sensitive to road slope; leveling systems based on gas-liquid separation are prone to coupling interference during multi-axis linkage, often compromising reliable attitude control. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention proposes an integrated equipment for the transportation, erection, and adaptive leveling of small spacecraft. This equipment includes: a carrier chassis 1, a multi-stage erection mechanism 8, an adaptive leveling platform 3, and an intelligent control system 2. After the small spacecraft 4 is loaded onto the adaptive leveling platform 3, the intelligent control system 2 drives the multi-stage erection mechanism 8 and the carrier chassis 1 to achieve automated coordination of transportation, erection, and leveling. The coordinated control and execution process of this integrated equipment includes:

[0005] S1: Acquire terrain mapping data of the launch site and plan the optimal transportation path and target docking posture of the carrier chassis 1 in the intelligent control system;

[0006] S2: After the carrier chassis 1 transports the spacecraft to the target position, it activates the parking locking mechanism and deploys the support legs for initial physical fixation.

[0007] S3: Using the ideal vertical attitude model of spacecraft launch as prior knowledge, construct the optimal kinematic solution matrix for multi-axis cooperative leveling;

[0008] S4: The sensor array is used to collect the current tilt angle and height data of the adaptive leveling platform in real time, and input it into the optimal kinematics solution matrix for forward inference to obtain the expected value of the compensation stroke of each leveling cylinder.

[0009] S5: The intelligent control system drives the adaptive leveling platform to perform coarse leveling based on the expected value of the compensation stroke to obtain the reference horizontal plane;

[0010] S6: On the reference horizontal plane, drive the multi-stage erection mechanism 8 to smoothly flip the spacecraft from a horizontal state to a vertical launch state;

[0011] S7: After erection, based on the attitude deviation fed back from the sensors, the control error function of the system is calculated, and the platform parameters are continuously adjusted in a closed loop. When the attitude error converges to within the tolerance range, adaptive fine-tuning is completed. Furthermore, the specific theoretical model for constructing the optimal kinematic solution matrix is ​​as follows: Let the coordinate system of the ground fixed base be... The coordinate system of the moving platform is The adaptive leveling platform adopts a multi-actuator parallel configuration, and its number of actuators is... Order No. The vector of the hinge point position of each actuating cylinder on the static platform is: The position vector of the hinge point on the moving platform is The translation vector of the moving platform relative to the static platform is... The attitude rotation matrix is (Based on Euler angle roll) Looking up and down ,yaw (Solve). Then the first... The theoretical target displacement vector of each actuated cylinder and its length It can be obtained from the inverse kinematic equations:

[0012]

[0013] The system will use the above calculations to obtain As the expected compensation stroke value for each leveling cylinder, the pose compensation command is generated by comparing the actual length feedback from the displacement sensors built into the actuators. Simultaneously, the control algorithm screens for singularities and out-of-bounds strokes based on the calculated lengths of each actuator, removing action sequences that may cause mechanical interference. It calculates the time and energy consumption of all feasible motion trajectories, and outputs the action sequence with the smoothest path and lowest energy consumption as the optimal kinematic solution. Furthermore, the adaptive leveling platform's attitude data acquisition and calculation process includes: using multi-dimensional tilt sensors and laser rangefinders to obtain the initial attitude Euler angles and spatial displacement in the equipment coordinate system; and based on the spacecraft's center of mass distribution... Dynamic modeling and static calculations are performed in the following directions; pose errors are decomposed longitudinally, laterally, and vertically, with the platform's geometric center as the origin; and the above error data are subjected to Kalman filtering for noise reduction and normalization. The state equation and observation equation of the filtering algorithm are defined as follows:

[0014]

[0015] in, for The real attitude state matrix of the time platform Here is the state transition matrix. The sensor measurement value. For the observation matrix, and These are system process noise and measurement noise, respectively. They are estimated using prior data and Kalman gain. The iterative updates output an effective attitude feedback dataset usable by the control system. Furthermore, the intelligent control system drives the adaptive leveling platform using an adaptive PID control law, the formula of which is:

[0016]

[0017] in, For control system output, This represents the deviation between the current pose and the target pose. This is the proportionality coefficient. The integral time constant is... Here, represents the differential time constant. To address the nonlinear disturbances caused by the dynamic shift of the center of mass during spacecraft erection, this invention introduces a parameter adaptive tuning mechanism based on fuzzy rules. The control system adjusts the parameter tuning based on the deviation. and the rate of change of deviation Real-time online parameter correction:

[0018]

[0019] Meanwhile, the error function expression for the system's multi-axis coordinated leveling is:

[0020]

[0021] in, To account for attitude error, For the first The weighting coefficient of each support leg and These are the measured roll angle and pitch angle, respectively. and The target reference angle.

[0022] The beneficial effects of this invention are:

[0023] (1) This invention proposes a highly integrated equipment design for high-frequency launch of small spacecraft, which maximizes the reduction of the launch preparation cycle while effectively reducing the risk of multi-equipment docking and improving the flexibility of launch missions.

[0024] (2) This invention makes full use of the kinematic knowledge of parallel mechanisms and multi-sensor fusion data to generate the optimal kinematic solution matrix. The platform attitude is accurately compensated through the solution matrix, resulting in an adaptive leveling method with high reliability and strong anti-disturbance capability.

[0025] (3) The present invention utilizes the servo actuator cylinder 10 for flexible drive, which effectively expands the range of adaptability of the erection angle. At the same time, the acceleration changes smoothly during the erection process, reducing the impact on the spacecraft load.

[0026] (4) The present invention uses intelligent feedback algorithm for closed-loop control, without adding extra complex mechanical structure, while the system has stronger unstructured terrain adaptability and leveling accuracy. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of an integrated equipment for transporting, erecting, and adaptively leveling small spacecraft, provided by an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the adaptive leveling platform structure provided in this invention example;

[0029] Figure 3 This is a flowchart of the optimal multi-axis collaborative leveling control logic provided in this invention example;

[0030] Figure 4 This is a schematic diagram of the attitude error convergence curve and experimental results provided in this invention example.

[0031] In the diagram: 1. Carrier chassis; 2. Intelligent control system; 3. Adaptive leveling platform; 4. Small spacecraft; 5. Travel sensor; 6. Support leg frame; 7. Sensor array; 8. Multi-stage erection mechanism; 9. Bearing chassis; 10. Servo actuation cylinder; 11. Moving platform; 12. Fixed base; 13. Universal hinge / ball joint. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] An integrated equipment for transporting, erecting, and adaptively leveling small spacecraft and its collaborative control method are disclosed. The method includes: acquiring current terrain and spacecraft payload data, and performing preliminary fixing and leveling of the equipment chassis; inputting the processed sensor data into an intelligent control model to drive a multi-stage erection mechanism to erect the spacecraft; the control model includes an attitude decoupling network and an adaptive PID controller.

[0034] Taking a non-standard launch site in the field as an example, the specific implementation method includes the following steps:

[0035] Step (1): After the spacecraft 4 is loaded onto the integrated equipment, the carrier chassis 1 travels to the launch pad. The intelligent control system 2 reads data from the multi-dimensional tilt sensor 7 to assess the ground slope. If the measured longitudinal or lateral slope exceeds the limit safety threshold of 8°, the system alarms and automatically calculates the optimal correction angle. The carrier chassis 1 activates the parking locking mechanism and deploys the hydraulic support legs 6 for initial physical fixation, establishing the initial reference plane.

[0036] Step (2): Start the erection mechanism 8 to begin the lifting action. During the erection process, the system monitors the attitude changes and center of mass transfer trajectory of spacecraft 4 in real time at a high-frequency sampling rate of 200Hz, and feeds the dynamic attitude data into the control center in real time.

[0037] Step (3): The adaptive leveling platform 3 is started. Using the multi-dimensional tilt sensor 7 for forward inference and combined with the current erection status, the inverse kinematic equations of the spatial parallel mechanism are used. The target stroke of the six servo actuators 10 is calculated. Subsequently, the six servo actuators 10 operate synchronously under the precise drive of the electro-hydraulic servo valve to perform rapid coarse leveling, offsetting the shift in the center of gravity at the bottom angle of the terrain and during the initial erection, and controlling the overall tilt angle within a safe range of ±1°.

[0038] Step (4): Fine-tune the network model, and correlate the coarse leveling error output by the vehicle chassis 1 with the centroid offset of the erecting mechanism 8 caused by the increase in the erection angle (such as when crossing the 45° to 75° range) point by point. After Kalman filtering and noise reduction, input the model into the intelligent control system 2. The intelligent control system 2 is based on the adaptive fuzzy PID algorithm (dynamic tuning). (Parameters), the six servo actuators 10 of the linkage adaptive leveling platform 3 perform high-frequency dynamic flexible compensation. Repeated attitude acquisition and fine-tuning until the spacecraft 4 is erected to 90° and the comprehensive verticality error is less than 2', the system locks all hydraulic and mechanical limits, and completes the integrated erection and precision leveling operation.

[0039] Figure 1 The integrated layout of the transport vehicle, erection mechanism, and adaptive leveling platform is shown. Figure 4In the graph: the horizontal axis represents time (s), and the vertical axis represents the overall attitude error (degrees); the solid line represents the fast convergence effect of the adaptive method of this invention, and the dashed line represents the severe fluctuations of the traditional non-adaptive method during the erection interference stage.

[0040] The above-described embodiments further illustrate the purpose, technical solution, and advantages of the present invention. It should be understood that the above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated equipment for transporting, erecting, and adaptively leveling small spacecraft, characterized in that, The system includes a launch chassis, a support chassis, an erection mechanism, an adaptive leveling platform, a sensor array, and an intelligent control system. The launch chassis is used to transport the small spacecraft to the target docking position and perform parking locking and initial physical fixation. The adaptive leveling platform is mounted on the support chassis and directly supports the small spacecraft. The adaptive leveling platform includes a fixed base, a moving platform, and six servo actuation cylinders. Each servo actuation cylinder is connected to the fixed base and the moving platform at both ends via universal joints or ball joints to form a spatial parallel leveling mechanism. Each servo actuation cylinder is equipped with a displacement sensor. The sensor array includes a multi-dimensional tilt sensor and a laser rangefinder for collecting the roll angle, pitch angle, and spatial displacement of the adaptive leveling platform. The erection mechanism drives the small spacecraft to rotate from a horizontal to a vertical launch position. The intelligent control system is electrically connected to the carrier chassis, the erection mechanism, the adaptive leveling platform, and the sensor array, and is configured to: before erection, solve for the expected compensation stroke of the six servo actuators based on the roll angle, pitch angle, and spatial displacement using the inverse kinematic equation of the parallel spatial leveling mechanism, and drive the six servo actuators to operate synchronously to complete coarse leveling; during the process of the erection mechanism driving the small spacecraft to flip, continuously acquire the attitude change and center of mass transfer trajectory of the small spacecraft, correlate the coarse leveling error with the center of mass offset corresponding to the current erection angle, perform Kalman filtering on the attitude data, and adjust the six servo actuators using a fuzzy adaptive PID algorithm based on the filtered attitude deviation and the rate of change of attitude deviation, so as to dynamically and flexibly compensate for the dynamic offset of the center of mass during the erection process.

2. The integrated equipment for transporting, erecting, and adaptively leveling small spacecraft according to claim 1, characterized in that, The transport chassis is equipped with hydraulic support legs; the intelligent control system is also configured to evaluate the longitudinal and lateral slope of the ground based on the data collected by the multi-dimensional tilt sensor, to alarm and calculate the correction angle when the longitudinal slope or the lateral slope exceeds 8°, and to drive the hydraulic support legs to unfold after parking and locking to establish an initial reference plane.

3. The integrated equipment for transporting, erecting, and adaptively leveling small spacecraft according to claim 1, characterized in that, The intelligent control system is further configured to: calculate the theoretical target length of the six servo actuator cylinders based on the positions of the hinge points of each static platform on the fixed base, the positions of the hinge points of each moving platform on the moving platform, the translation vector of the moving platform relative to the fixed base, and the attitude rotation matrix; compare the theoretical target length with the actual length detected by the corresponding displacement sensor to generate a pose compensation command; screen the action sequences corresponding to the theoretical target length for singularities and out-of-bounds strokes, and eliminate action sequences that would cause mechanical interference; and select the action sequence with the smoothest path and the least energy consumption as the leveling control sequence based on the execution time and energy consumption of the remaining action sequences.

4. A collaborative control method based on the equipment described in any one of claims 1-3, characterized in that, Includes the following steps: S1: Acquire terrain mapping data of the launch site, plan the transportation path of the transport chassis and the target docking position; after the transport chassis reaches the target docking position, execute parking lock and deploy hydraulic support legs to establish an initial reference plane; S2: The roll angle, pitch angle and spatial displacement of the adaptive leveling platform are collected using the multi-dimensional tilt sensor and the laser rangefinder. The expected value of the compensation stroke of the six servo actuators is calculated through the inverse kinematic equation of the spatial parallel mechanism, and the six servo actuators are driven to operate synchronously so that the adaptive leveling platform can complete the coarse leveling. S3: Activate the erection mechanism and continuously collect the attitude change and center of mass transfer trajectory of the small spacecraft during the process of the small spacecraft flipping from a horizontal state to a vertical launch state; S4: Correlate the coarse leveling error obtained in step S2 with the centroid offset corresponding to the current starting angle, and perform Kalman filtering on the correlated attitude data; S5: Based on the filtered attitude deviation and attitude deviation change rate, the proportional, integral and derivative parameters of the PID algorithm are adjusted online using fuzzy rules to drive the six servo actuators to perform dynamic flexible compensation, so as to offset the attitude error caused by the terrain tilt angle and the dynamic displacement of the center of gravity during the erection process. S6: Repeat attitude acquisition, filtering and dynamic flexible compensation until the small spacecraft reaches the vertical launch state and the attitude error converges to the set tolerance range, then lock the hydraulic circuit and mechanical limit.

5. The cooperative control method according to claim 4, characterized in that, Step S2, calculating the expected value of the compensation stroke, includes: taking the chassis as the static platform and the moving platform as the moving platform, and solving for the theoretical target length of each servo actuator based on the hinge point position vector of each servo actuator on the static platform, the hinge point position vector of each servo actuator on the moving platform, the translation vector of the moving platform relative to the static platform, and the attitude rotation matrix; screening for singularities and out-of-bounds strokes based on the theoretical target length, and eliminating action sequences that would cause mechanical interference; calculating the execution time and energy consumption of the remaining action sequences, and selecting the action sequence with the smoothest path and the least energy consumption.

6. The cooperative control method according to claim 4, characterized in that, Step S4, which involves performing Kalman filtering on the attitude data, includes: performing dynamic modeling and static calculations based on the centroid distribution of the small spacecraft; decomposing the attitude error into longitudinal, lateral, and vertical errors with the geometric center of the adaptive leveling platform as the origin; and using a preset state transition matrix and observation matrix to perform prior estimation and Kalman gain iterative updates on the data obtained from the multi-dimensional tilt sensor, the laser rangefinder, and the displacement sensor to obtain effective attitude feedback data for dynamic flexibility compensation.

7. The cooperative control method according to claim 4, characterized in that, In steps S3 to S6, attitude data is collected at a sampling frequency of 200Hz; in step S2, the overall tilt angle is controlled within ±1° by the synchronous operation of the six servo actuators; in the range of 45° to 75°, high-frequency dynamic flexible compensation is performed according to the centroid offset; when the tilt angle reaches 90° and the verticality error is less than 2′, the hydraulic circuit and the mechanical limit are locked.

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