159 results about "Attitude stability" patented technology

The invention relates to the technical field of automatic control, in particular to a four-rotor aircraft attitude control method and system based on sliding-mode control law and ESO. The method includes: using a sliding-mode control method to the three attitude angle loops of four rotors; using the ESO to estimate total system disturbance in real time; combining the sliding-mode control with the ESO to achieve attitude control of a four-rotor aircraft. Compared with an existing attitude control method, the method has the advantages that attitude stability of the four-rotor aircraft can be achieved, good tracking performance on attitude angle instructions is achieved, and high disturbance resistance is achieved as compared with common sliding-mode control.

The invention discloses a spacecraft attitude stability control method by using a biasing tether. The method comprises: a system dynamics model is established; a nonaffine non-linear system model is converted into an affine non-linear system model; speed information is used as a virtual control value and a controller is designed; the designed virtual control value is used a control instruction and a speed/angular speed controlled is designed; and an anti-saturation module is added into the controller and an influence caused by movement limitation of a tether connecting point can be suppressed. According to the invention, on the basis of movement of a biasing tether point, an attitude of a capture mechanism is controlled, thereby substantially reducing fuel consumption of the capture mechanism during the operation task process. In addition, the nonaffine non-linear system model is converted into the affine non-linear system model by means of first-order taylor expansion and that the similarity and error meet the Lipschitz condition is demonstrated; and when the system design is controlled, an adaptive compensation item compensation module error is designed. The method is simple and the practicability is high.

The invention relates to the quadrotor unmanned aerial vehicle fault-tolerant control, and aims to realize attitude stability under the condition of an actuator fault of a quadrotor unmanned aerial vehicle. The technical scheme adopted by the invention is that an observer-based quadrotor unmanned aerial vehicle fault-tolerant control method includes the following steps: first defining an inertia coordinate system {I}, a body coordinate system {B} and a target coordinate system {Bd}, and through analysis of an action principle of the actuator on the quadrotor unmanned aerial vehicle, an unknown diagonal matrix is utilized to represent influence of an actuator fault on kinetic characteristics of the quadrotor unmanned aerial vehicle, and a nonlinear kinetic model when a fault occurs in the quadrotor unmanned aerial vehicle actuator is obtained; a unit quaternion-based attitude representation method is adopted; and an observer technology based on an immersion-invariant set method is adopted to observe the actuator. The observer-based quadrotor unmanned aerial vehicle fault-tolerant control method provided by the invention is mainly applied to quadrotor unmanned aerial vehicle design and control occasions.

The invention discloses an aircraft attitude fault-tolerant control method based on dynamic control redistribution. The method includes the steps that firstly, an attitude angle rate loop dynamic equation of a near-space aircraft X-33 is given, and a control surface jamming and damage fault model is established; then according to the control surface damage fault model of an attitude angle rate loop, a self-adaptive sliding-mode observer is designed; the attitude angle loop and the designed observer dynamic equation are combined, and an angle loop controller and an angular speed loop controller are designed. Accurate damage fault information, interference information and the like are not needed, the information is implied in the designed self-adaptive sliding-mode observer, the implicit information is fed back to a pseudo control law and online distribution algorithm LMI in real time, and then robust fault-tolerant control is achieved. Finally, the designed method is applied to attitude stability control and tracking control of the near-space aircraft under the control surface fault condition, flight attitude robust fault-tolerant control is achieved, and good control performance and effects are achieved.

The invention relates to the technical field of spacecraft control and particularly discloses an integrated analyzing and setting method for control parameters of a three-loop automatic pilot. The integrated analyzing and setting method comprises the following steps of: firstly, establishing a control loop model of the three-loop automatic pilot; secondly, setting a pitching motion relative damping coefficient after compensating an attitude angular velocity feedback circuit to acquire an attitude angular velocity control parameter and the open-loop cross-over frequency of the attitude angular velocity feedback circuit; thirdly, acquiring an open-loop gain system of a control system according to an open-loop transmission function of the control system and acquiring a closed-loop transmission function which is inputted to a guidance spacecraft by an overload instruction after correction and is outputted in an overload manner; and fourthly, acquiring the attitude angular velocity control parameter, an overload feedback control parameter and an overload instruction correction parameter. According to the integrated analyzing and setting method, the solving of a nonlinear equation is avoided; in addition, attitude stability and attitude control precision of the guidance spacecraft can be maintained by the acquired parameter under various single deviations and combined deviation and the balancing state of the spacecraft required by the guidance instruction is quickly realized.

The invention relates to a finite-time adaptive fault-tolerant control method for a rigid spacecraft based on an enhanced bipower reaching law and a fast terminal sliding mode surface. In order to solve a problem of low attitude stability under the fault of an aircraft actuator with centralization uncertainty, the invention designs an adaptive fast terminal sliding-mode composite control scheme bycombining adaptive control based on a sliding mode control method with the enhanced bipower reaching law. On the one hand, an uncertain and disturbed upper bound is estimated and compensated by usingthe adaptive technique; and on the other hand, on the basis of the quickness and high robustness of the fast terminal sliding mode, finite-time attitude stability of the aircraft system is realized.With the control method, buffeting of the sliding surface and control torque is reduced; and a finite-time boundary control method of the system is realized under the conditions of uncertainty and interference existence in the system.

The invention relates to a spacecraft attitude stability judgement method utilizing RCS. The method is characterized in that the steps are as follows: when the format of a RCS sequence is correct, the RCS sequence is segmented, discrete wavelet transform is then carried out, so that a discrete wavelet transform coefficient is obtained, and wavelet transform characteristics are extracted; the transform characteristics are normalized and then inputted into a three-layer BP (back-propagation) neural network, and when a BP neural network error function E (W) reaches a minimum value, the attitude stability of a spacecraft is judged according to the output value of the BP neural network; 0 in the output value represents attitude stabilization, and 1 in the output value represents attitude rolling. The method can utilize the characteristics to judge the attitude stability of the spacecraft, and measured data prove that the space target attitude stability identification rate of the method is more than 90 percent and that the operation speed is high ( single target identification time is less than 2s).

The invention provides a dragged target attitude stability control method based on thrust control of a tethered space tug. The method includes following steps: 1, performing a system hypothesis, wherein the tethered space tug is an integral body including a tug, a target, and an elastic-connection tie rope, and the tug and the target are located at two ends of the tied rope; 2, calculating a reference trajectory based on optimization; 3, deducing a robust global terminal sliding mode controller; and 4, adding an anti-saturation module and a thrust prediction and correction module. By the above steps, the robust global terminal sliding mode controller obtained in step 3 and the anti-saturation module and the thrust prediction and correction module obtained in step 4 are combined so that the designed dragged target attitude stability controller based on thrust control of the tethered space tug and the control method thereof are obtained, the controller designed by the method can satisfy the constraint demand, and the loosening of the tied rope is also prevented by the designed thrust prediction and correction module.

The invention provides a sun inertia pointing master-slave non-contact dual-super satellite platform comprising a load cabin. The load cabin comprises a first side plate, a partition plate, a first top plate, a first bottom plate, a solar cell, an effective load data transmission antenna, a data processing unit and a relative position sensor. The first top plate is a sun observation load datum plate; the first bottom plate is a magnetic suspension direct force control mechanism mounting angle plate; a sun observation load is mounted on the sun observation load datum plate; a magnetic suspension direct force control mechanism and a part of the structure of a two-cabin locking and unlocking mechanism are mounted on the magnetic suspension direct force control mechanism mounting angle plate;the relative position sensor is mounted on the magnetic suspension direct force control mechanism; and the load cabin is connected to the upper portion of a platform cabin in a butting mode. The requirements for the sun observation load with ultrahigh pointing precision and ultrahigh attitude stability can be met.

The invention discloses an aircraft stability control method. The method comprises steps: S1, dynamic coefficients affected by a jet vane and an air rudder in pitching, yawing and rolling channels aresuperimposed respectively, and according to the dynamic coefficients after superposition, missile body transfer functions in the pitching, yawing and rolling channels are calculated; S2, a three-loopcontrol structure for the pitching, yawing and rolling channels is established, wherein the three-loop control structure comprises an angular rate feedback loop, a pseudo-attitude angle feedback loopand a trajectory inclination rate feedback loop; S3, according to the missile body transfer functions in the pitching, yawing and rolling channels and the three-loop control structure, pitching, yawing and rolling channel control equations are generated respectively; and S4, the control parameters in the pitching, yawing and rolling channel control equations are matched, and three-channel dynamical decoupling is realized. The air rudder and the jet vane are adopted for linkage control on the aircraft, steady-state errors are eliminated, system divergence caused by integral overshoot is prevented, and attitude stability is realized.

The invention provides a modeling and self-adaptive control method for a four-axis aircraft carrying uncertain loads, and relates to the control technical field of multi-rotor unmanned aerial vehicles. The method comprises the following steps of firstly, carrying out the dynamics accurate modeling under the condition that the four-axis aircraft carries uncertain loads so as to obtain the differential equation form and the column array form of a kinetic model; secondly, designing a self-adaptive controller based on the kinetic model; finally, designing a feedback control law and controlling the attitude of the four-axis aircraft carrying uncertain loads through selecting proper parameters. According to the technical scheme of the invention, a modeling and self-adaptive control method is provided. Based on the feedforward control, the dynamics uncertainty of the aircraft is subjected to parameter adjustment, so that the aircraft is adapted to the current environment. Therefore, the attitude stability of the four-axis aircraft carrying uncertain loads is effectively improved. Based on the design of the Lyapunov method, the stability and the convergence can be guaranteed, and the number of control parameters can be reduced at the same time. The attitude control precision and the flight response speed of the four-axis aircraft carrying loads are effectively improved.

The invention discloses an adaptive fault-tolerant attitude control method in an initial state stage of a satellite. The method comprises steps: in an initial state control stage after successful satellite and rocket separation, a satellite rotational inertia uncertainty model during a solar panel unfolding process is built; a satellite attitude dynamic model is built; a preset performance function is used to build an attitude nonlinear mapping model; and based on the built satellite rotational inertia uncertainty model during the solar panel unfolding process, the satellite attitude dynamic model and the attitude nonlinear mapping model, a backstepping method is used to design an adaptive fault-tolerant controller. Through the method, the rotational inertia uncertainty of the satellite inthe initial state control stage and the attitude stability problem in the case of actuator failure and under effects of an external disturbance torque can be solved, the fault-tolerant ability and the robustness of the attitude control system are ensured, and the attitude convergence speed, overshoot and convergence errors are ensured to meet the preset requirements.

The invention discloses a space robot mechanical arm arresting control system. The space robot mechanical arm arresting control system comprises two loops, namely, an inner loop and an outer loop, inthe outer loop, the system achieves the attitude stability of a space robot mechanical arm base platform in the arresting process through a PD controller, and in the inner loop, the system controls amechanical arm to achieve arresting maneuvering on a non-cooperative target through a reinforce learning control system based on reinforce learning. The invention further discloses a reinforce learning method for controlling the reinforce learning control system of the mechanical arm in the inner loop of the system and a space robot dynamics modeling method of the space robot mechanical arm arresting control system. According to the space robot arresting control system, the reinforce learning method and the dynamics modeling method, compared with PD control, the posture disturbance of the baseplatform under reinforce learning RL control is smaller, the movement process of the tail end of the mechanical arm is more stable, the control precision is higher, moreover, the motion flexibility of the mechanical arm under the reinforce learning RL control is good, and the autonomous intelligence is achieved to the greater extent.

The invention relates to a double-planar-array three-dimensional plotting system, in particular to a double-planar-array three-dimensional plotting system based on a minosatellite platform, and aims to solve the problems that a processing method of an existing plotting system is complicated, requirements for attitude stability of a satellite platform is high, data cannot be transmitted in real time, processing is inconvenient and the like. The plotting system comprises a house-keeping system, a measurement and control system, an attitude and orbit control system, a power supply system, a thermal control system, a first star sensor, a second star sensor, a data transmission system, a three-axis gyroscope, a foresight planar array camera, a rearview planar array camera and a foresight and rearview optical system in-orbit included angle detection system. The foresight planar array camera and the rearview planar array camera share an imaging and focusing controller; the foresight and rearview optical system in-orbit included angle detection system is used for detecting the changes of a foresight and rearview optical system in-orbit included angle in orbit in real time. The system develops a large-scale double-planar-array three-dimensional plotting research based on a minisatellite in combination with satellite-borne integration and low-orbit operation techniques, reduces the requirements for satellite attitude and orbit measurement accuracy and can realize plotting without the aid of control points.

The invention relates to an apparatus and method of improving spacecraft attitude stability, belonging to the spacecraft attitude dynamics and vibration inhibition field. The framework bearing of each SGCMG is provided with a vibration isolation element; each vibration isolation element includes a plurality of metal springs respectively in connection with the internal wall and the external wall of the vibration isolation element through spherical hinges. The internal wall of the vibration isolation element sleeves the framework bearing of an SGCMG so as to be in connection with the framework bearing of the SGCMG; the external wall of the vibration isolation element is directly in fixed connection with a satellite body. The vibration isolation elements can effectively solve the vibration problem of an SGCMG, and possess a decoupling characteristic so as to effectively and rapidly realize the parameter design of vibration isolation elements; in addition, the vibration isolation elements can greatly improve satellite attitude stability.

The invention relates to an underwater robot-underwater robot arm system, belonging to the field of underwater robots and comprising three parts: an underwater robot body, an underwater manipulator and an auxiliary adjusting device; the underwater robot body is an autonomous underwater robot without cables, and the power system of the underwater robot body uses the under-actuated mode to control the attitude and motion of the underwater robot, and the drive system of the underwater robot body consists of single propellers and one cruciform of rudder, which are installed at the stern of the underwater robot body; the system uses the underwater manipulator with four degrees of freedom and five functions, and the underwater manipulator consists of two rotative joints and two pendulum joint and one manipulator grasp, and the auxiliary adjustment device is installed directly below the underwater robot and is close to the stern. The device is driven by a lead screw slider mechanism and a servo motor. By moving the slider, the adjustment of the center of gravity of the underwater robot can be achieved, which compensates the influence of the underwater manipulator on the longitudinal change of the center of gravity of the underwater robot during the movement, thereby achieving the attitude stability of the underwater robot.

The invention provides a fuzzy PID motion control method of an underwater robot based on ESO. According to the fuzzy PID motion control method, the defect that as for an existing PID control technology, parameter adjusting cannot be conducted under a complex marine environment is made up based on ESO and PID fuzzy logic control, the motion attitude of an underwater vehicle and environmental disturbance are estimated and compensated under the condition of external environmental disturbance, and finally, motion attitude stability of the underwater vehicle under the complex marine environment isachieved. The fuzzy PID motion control method comprises the following stages of (1) information obtaining and demand analysis, (2) system state prediction and interference compensation, and (3) PID parameter self-adjustment and AUV motion control.

The invention discloses a solar capture method based on angular velocity estimation information and a solar sensor. The method comprises the following steps of: estimating an inertial angular velocityof a satellite body in real time by utilizing dynamic and kinematic equations of the satellite body; measuring a specific azimuth of the sun appearing on a satellite and an estimation value of an inertial angular velocity of the satellite by using a 0-1 type solar sensor, and searching the sun so that the simulated solar sensor faces the sun; calculating a two-dimensional attitude angle accordingto the measurement information of the simulated solar sensor; controlling the satellite attitude capture by utilizing the two-dimensional attitude angle of the simulated solar sensor and the satellite inertial angular velocity estimation information, and reducing an included angle between a sun vector and a certain axis of the satellite body, so that the sun is captured by the sun-facing orientation surface of the satellite. According to the method, the sun is searched by utilizing the inertia angular velocity estimation information and the 0-1 type solar sensor, the sun is captured by utilizing the inertia angular velocity estimation information and the simulated solar sensor, and the energy supply and attitude stability of the satellite under a full-attitude mode are ensured.

The invention discloses a high-stability underwater measuring platform, and belongs to the technical field of marine monitoring equipment. The underwater measuring platform comprises a main floating body, a buoyancy compartment, a ballast tank, a vibration damping device, connecting rods and a buffering tie belt; an underwater monitoring instrument is installed in a pressure-resistant cover of thevibration damping device; the vibration damping device is installed in the main floating body through elastic connecting cables, the two lateral sides of the main floating body are respectively connected with the buoyancy compartment and the ballast tank through the connecting rods, and the buoyancy compartment, the main floating body and the ballast tank are vertically distributed; the measuringplatform is horizontally floated under water by adjusting the position of a balancing weight in the ballast tank; the underwater monitoring instrument in the vibration damping device is electricallyconnected with a storage unit installed in the ballast tank, and the storage unit is used for receiving and saving detection information of the underwater monitoring instrument. According to the underwater measuring platform, through split structure design and reasonable overall configuration, the attitude stability of the underwater platform is improved, and the flow noise impact of the platformis reduced.

The invention relates to a position and attitude stability control method for an operational flying robot after grasping. The position and attitude stability control method comprises the steps that firstly, a four-rotor unmanned aerial vehicle carrying mechanical arm system is modeled through a Newtonian-Euler equation method; then, gravity center offset system parameters are considered in a position controller, and the gravity center offset system parameters are compensated in sliding mode control, so that a four-rotor unmanned aerial vehicle platform flies according to a target trajectory; then, the expected roll-over angle, the expected pitch angle and the lift required by the four-rotor unmanned aerial vehicle platform flying according to an expected trajectory are calculated; and it is considered that gravity center offset control parameters and the inertia tensor are not constants in an attitude controller, adaptive law is added into the attitude controller to estimate the gravity center offset control parameters and the inertia tensor, a CMAC neural network is added to approximate a real value of the inertia tensor online, the required input torque is calculated, and then the rotational speeds of four rotors are calculated simultaneously. According to the position and attitude stability control method for an operational flying robot after grasping, the problems of unknown time-varying parameters, insufficient stability of attitude control and insufficient stability of gravity center offset to the position in attitude control law can be solved.

The invention discloses an underwater video shooting system. The underwater video shooting system comprises an underwater robot mechanism, two video cameras, a colorful LED illumination lamp, a triaxial motion platform, a main control system, an attitude sensing system, a motion driving mechanism, and a remote control platform. The two video cameras, the colorful LED illumination lamp, the triaxial motion platform, the main control system, the attitude sensing system, and the motion driving mechanism are disposed in the underwater robot mechanism. The main control system is connected with the remote control platform by an optical fiber, and is used for realizing real-time remote control and image data transmission control. The main control system is connected with the two video cameras, the colorful LED illumination lamp, the triaxial motion platform, the attitude sensing system 106, and the motion driving mechanism, and then the motion control of the underwater robot mechanism in the water and underwater environment illumination control are realized, and according to attitude information acquired by the attitude sensing system, the triaxial motion platform is regulated in a real-time manner, and then the attitude stability and the target tracking of the video cameras are maintained, and then a binocular three-dimensional video shooting and photo shooting function in the underwater environment is realized in a real-time manner. The underwater video shooting system is widely used for the video shooting application in the underwater environment.

The invention discloses a satellite attitude stability control method and device. The method comprises the steps of: (1) obtaining a present satellite attitude stability mode, wherein the present stability mode is one of a zero-momentum stability mode or a bias-momentum stability mode; (2) receiving a switching instruction sent from the ground according to the task requirement, wherein the switching instruction includes switching information of a stability mode required to be executed, and the stability mode required to be executed is one of the zero-momentum stability mode or the bias-momentum stability mode; (3) judging if the stability mode required to be executed is the same with the present stability mode, if not, performing the step (4); and (4) switching the present stability mode to the stability mode required to be executed, and performing the satellite attitude stability control. The method realizes the free switching between the bias-momentum stability and the zero-momentum stability through introducing the ground intervention according to the instruction sent from the ground, so that the control system flexibility is improved.

The invention discloses a flexible satellite active vibration suppression method based on component force synthesis and fixed time convergence. The flexible satellite active vibration suppression method comprises the following steps of step 1, establishing a flexible satellite attitude dynamics model with two pairs of large solar panels, and simultaneously establishing a dynamic model of a piezoelectric intelligent material actuator; step 2, designing a fixed time convergence sliding mold controller; step 3, designing a disturbance observer for ensuring a double-layer self-adaptive law with fixed time convergence characteristics; and step 4, outputting a dynamic model of the piezoelectric intelligent material actuator, implementing processing by adopting a continuous component force synthesis control idea, generating a new control torque command to be applied to a flexible accessory to counteract the influence of elastic vibration, and ensuring the attitude stability of a satellite body. The flexible satellite active vibration suppression method has the advantages of high attitude control precision and strong robustness. Meanwhile, a continuous component force synthesis method is introduced into a closed-loop control process through a piezoelectric sheet attached to the flexible accessory, vibration is inhibited, and the system interference is reduced.

The invention discloses an automobile electronic control air suspension whole automobile attitude control system and method in the technical field of automobile air suspensions. The system comprises agyroscope sensor for detecting the automobile body bank angle and the automobile body pitch angle, and four automobile body height sensors for detecting movable journey information of a front left suspension, a front right suspension, a rear left suspension and a rear right suspension, the gyroscope sensor and the output ends of the automobile body height sensors are connected with the input endof a whole automobile attitude controller through CAN buses, the whole vehicle attitude controller is composed of a front left air spring control module, a front right air spring control module, a rear left air spring control module and a rear right air spring control module, the output end of the whole automobile attitude controller is connected with the input end of an electromagnetic valve drive circuit, and the output end of the electromagnetic valve drive circuit is connected with eight electromagnetic valves respectively. The whole automobile attitude controller determines a charging anddischarging control signal capable of keeping the automobile body attitude stability in the driving process according to the suspension movable journeys, the automobile body bank angle and the automobile body pitch angle, and the automobile body attitude is rapidly and effectively adjusted by an automobile under complex working conditions.

The invention provides an underwater robot control system with eight propellers, an underwater robot is provided with four top propellers and four vector propellers, and the eight propellers work together or partially to complete six-degree-of-freedom movement of an intelligent robot platform. The attitude stability is ensured, and directional, fixed-depth and fixed-speed sailing can be realized. A comprehensive control computer of the control system is connected with a plurality of sensor units through an RS485 bus, is used for depth temperature measurement, attitude measurement, speed measurement and water leakage monitoring of the underwater robot, and is also provided with an illumination and image transmission module to obtain real-time video information of an underwater target, brightness control of an auxiliary illumination light source is controlled by using the RS485 bus, and an operator can perform operation control on the underwater robot more conveniently.