315 results about "Spacecraft attitude control" patented technology

The invention relates to a spacecraft attitude integral sliding mode fault tolerance control method taking consideration of a performer fault and provides a robustness attitude active fault tolerance control method based on an integral sliding mode surface for problems of the performer fault, external disturbance and control moment amplitude limits in a spacecraft attitude control process. The method comprises steps that firstly, a spacecraft attitude dynamics model taking consideration of the performer fault and containing external disturbance is established; secondly, on the condition that a performer is not in fault, a designed nominal controller can guarantee system stability, and input saturation amplitude limits can be easily satisfied through adjusting controller parameters; lastly, the fault information is introduced to design an integral sliding mode controller, robustness of external disturbance and the performer fault can be effectively improved, system stability is analyzed on the basis of an Lyapunov method. The method is advantaged in that stability of the attitude control system is guaranteed when a spacecraft operating on orbit generates the performer fault, and relatively strong fault tolerance capability and external disturbance robustness are realized.

The invention relates to a flexible spacecraft attitude control system and a flexible spacecraft attitude control method in allusion to flywheel low-speed friction. The system comprises six modules which are a flexible spacecraft dynamics real-time simulation module with actuating mechanism characteristics, a flexible spacecraft kinematics real-time simulation module, an attitude measurement module, an attitude determination module, an attitude control module and an executing mechanism module, wherein the flexible spacecraft dynamics real-time simulation module with the executing mechanism characteristics comprises a spacecraft body, a flywheel and flexible appendage dynamics; the flexible spacecraft kinematics real-time simulation module can select different types of attitude description modes according to task requirements; the attitude measurement module can select different real sensors and sensor simulators according to the task requirements; the attitude control module comprises a conventional PID control method, a robust control method and the flexible spacecraft attitude control method in allusion to flywheel low-speed friction, and switching can be carried out according to the task requirements of the system; and the executing mechanism module comprises a real flywheel and a thruster simulator.

The invention relates to a rapid stable joint control method for attitude maneuver of spacecraft and belongs to the field of spacecraft attitude control and vibration control. The method is invented by absorbing advantages in spacecraft attitude maneuver trajectory planing technology and input shaping technology, and allows spacecraft to maneuver in task-required time and keep attitude quickly stable within index required values after maneuvering. Torque outputting capacity of a spacecraft attitude control actuator and maximum angular velocity maneuverability of spacecraft are further considered comprehensively, so that output torque of the spacecraft attitude control actuator is easy to implement.

The invention discloses a rigid spacecraft performer multi-fault diagnosis and fault tolerance control method. According to the method, the kinetic and dynamic model of a rigid spacecraft attitude control system is put forward, a fault model for existing of both the performance failure fault and the deviation fault of a rigid spacecraft is established, and then a fault detection observer adopting the adaptive threshold technology and a fault estimation observer based on the adaptive technology are respectively established so that online real-time detection and estimation of the fault time and the concrete situation of the fault can be realized, and finally a backstepping sliding mode fault tolerance controller is designed according to fault information established by the fault estimation observer. Attitude stabilization control of the rigid spacecraft under the condition of the performer efficiency damage and the deviation fault can be realized, and the influence of external disturbance on the system and the observers can also be considered in the design process. Besides, the fault detection observer and the fault estimation observer can be independently designed so that the engineering application can be more easily implemented.

The invention discloses a composite anti-interference controller comprising measurement and input time delay for a flexible spacecraft and relates to attitude control of the flexible spacecraft under time-varying delay and multi-source interference. The method comprises the following steps of: establishing a dynamical model of the flexible spacecraft; constructing a composite anti-interference controller comprising measurement and input time delay, estimating and performing feed-forward compensation on the anti-interference controller according to an interference observer comprising measurement time delay with interference design caused by vibration of flexible accessories, and designing a state feedback H8 controller to suppress the anti-interference controller according to the norm-bounded interference; designing gain of the interference observer to guarantee the stability of an interference estimated error dead time delay equation according to the 3/2 stability theorem; and finally, designing the gain of the state feedback H8 controller for a composite control system comprising measurement and input time delay based on a convex optimization algorithm, so that the system is stabilized, and a certain H8 performance is met. The composite anti-interference controller has the advantages of high interference resistance, convenience in design and the like and can be used for the attitude control of the flexible spacecraft comprising measurement and input time delay.

The invention provides a method for performance evaluation of a spacecraft attitude control ground simulation system. According to the method, the credibility of a dynamic system, a kinematics system, a measurement system and a control system is studied based on the simulation system credibility theory, the overall credibility of the spacecraft attitude control ground simulation system is obtained through comprehensive calculation, and then the performance of the spacecraft attitude control ground simulation system is evaluated. According to the evaluation method, the credibility of the ground simulation system and an actual satellite attitude control system is considered from all aspects, simulation data are fully utilized, and the credibility of the ground simulation system is described objectively and quantitatively; the theoretical basis is reliable, the calculation process is simple, the application range is wide, and a new idea and reference are provided for performance evaluation study of other simulation systems.

The invention provides a testing device and a method applicable for spacecraft high-stability pointing control. The testing device comprises a base, an air bearing, an instrument platform, a spacecraft pointing unit, a spacecraft attitude control unit, a platform data instruction transmitting-receiving system, a mark point, a target measuring head unit, a reflection prism, a counteractive momentum wheel system, an image processing unit, a photoelectric auto-collimator, a laser tracker, an off-platform data instruction transmitting-receiving system and a camera. According to the device and the method, the characteristics of a micro-interference moment environment are simulated by fully using the air bearing; as the high-precision position and attitude measuring techniques of equipment such as the image measuring unit, the laser tracker and the photoelectric auto-collimator are combined, the goal of spacecraft high-stability pointing control test can be realized; the precision is high; the stability is good; and the engineering realization is facilitated. The device and the method can be used for a high-precision pointing control test on spacecraft such as various high-precision weather and military reconnaissance satellites and space-based offense and defense platforms.

The present invention relates to a spacecraft attitude fault-tolerant control method based on an iterative-learning disturbance observer. In order to solve the problem that actuator faults and external disturbances might occur during the attitude control process of the on-orbit operation of a spacecraft in the prior art, the invention provides an active fault-tolerant control method based on the iterative-learning observer. The method comprises the steps of firstly, establishing a dynamic model for the attitude control system of a spacecraft in considering the fault of an actuator in the attitude control system of the spacecraft and the external disturbance in the space of the spacecraft; secondly, estimating and designing a generalized disturbance torque of the iterative-learning disturbance observer composed of the actuator fault information and the external disturbance; finally, based on the estimated generalized interference, designing an active fault-tolerant controller. Based on the method, the stability of the attitude control system of the spacecraft, when the actuator of the spacecraft has a fault and the external disturbance exists in the space of the spacecraft, can be ensured. Meanwhile, the precision requirement of an actual control system is met. The method is strong in fault-tolerant ability and good in robustness for the external disturbance.

The invention relates to a magnetically suspended gyroscope flywheel which can be used as a three-free degree attitude control actuator and a two-free degree attitude sensor of a spacecraft like a satellite and the like, and the magnetically suspended gyroscope flywheel mainly comprises a flywheel rotor, an axial magnetic bearing, a radial magnetic bearing, a protection bearing, a displacement sensor, a seal cover, a mounting shaft, a base, a motor, and other parts. The magnetic bearing is adopted for carrying out five-free degree suspension on the flywheel rotor, the flywheel rotor is driven to rotate around a rotating shaft by the motor, and the axial free degree control torque is outputted; the flywheel rotor is controlled to realize the torsion around an X axis or a Y axis of a housing by the axial magnetic bearing, and the radial two-free degree control torque is outputted; and the two-free degree attitude angular velocity of the spacecraft relative to inertia space can be sensed. The magnetically suspended gyroscope flywheel integrates the three-free degree attitude control actuator and the two-free degree attitude sensor of the spacecraft into a whole, thereby reducing the volume of an attitude control system of the spacecraft, reducing the weight of the attitude control system and being particularly applicable to being applied as the attitude control system of the spacecraft like the satellite and the like.

The invention discloses a flexible spacecraft underactuated system based on the switching control method and an attitude control method of the flexible spacecraft underactuated system based on the switching control method and belongs to the technical field of spacecraft attitude control. According to the flexible spacecraft underactuated system based on the switching control method and the attitude control method of the flexible spacecraft underactuated system based on the switching control method, a dynamical model of a flexible spacecraft with an execution mechanism completely ineffective is established, coupling, caused by elastic vibration of a flexible accessory, with a rigid body is taken as an uncertainty of the system, a dynamical model of a conversion system is a standard nonlinear model, all states are divided into three sliding model surfaces according to the layering sliding model idea, an equivalent control component is designed for the first layer of sliding model surface according to the Filippov equivalent theorem, a switching control law is designed by means of the second layer of sliding model surface and the third layer of sliding model surface, and a final control law is formed by combining equivalent control input and the switching control law. By the adoption of the flexible spacecraft underactuated system based on the switching control method and the attitude control method of the flexible spacecraft underactuated system based on the switching control method, the defect that in the prior art, a flexible spacecraft can not operate normally under the condition that an actuator becomes ineffective completely during operating of the flexible spacecraft is overcome, and operating reliability of a flexible spacecraft attitude control system is improved.

The invention provides an inertial system spacecraft attitude control/angular momentum management method including four steps. The invention aims to solve the problems of control moment gyro angular momentum accumulation caused by gravitation gradient moment and other interference moments in an inertial system, the gravitation gradient moment is adopted to balance the gestures, and a space station angular momentum management controller based on pole assignment is designed. A space station linear model is established under the inertial system, the infeasibility of the inertial system angular momentum management in the pitch axis direction is analyzed, the pitch axis is decoupled from a rolling/yaw axis, and the CMG angular momentum in the pitch axis direction is not restrained, constant disturbance, disturbance being one-time of the track frequency, and disturbance being twice of the track frequency are brought into a state equation to suppress the influence to the pitch axis gestures, and a linear quadratic algorithm based on pole assignment is adopted to solve a feedback gain matrix. The algorithm prevents the selection of cost matrix Q, and based on the requirement of the system performance, the closed-loop poles can be configured to a specified area at the left side of a complex plane imaginary axis, and at the end, the feasibility of the algorithm is verified by the simulation results.

The invention provides a flexible satellite neural network backstepping sliding mode attitude control method, relates to a flexible spacecraft attitude control method, and aims at solving a problem of perturbation generated by plate flexible vibration and antenna rotation and a problem of enhancement of steady state precision and stability of existing attitude control methods. According to the method, a flexible satellite attitude kinetic model is established firstly according to a spacecraft, and then a model formula is processed; a sliding mode attitude controller (which is expressed in the specification) based on a backstepping method is designed; then an RBF neural network approach (eta+htau)sgn(sigma) is adopted; the controller (which is expressed in the specification) is designed; and finally a complete attitude controller (which is expressed in the specification) is obtained. A three-axis attitude controller is designed respectively according to the aforementioned process. The flexible satellite neural network backstepping sliding mode attitude control method is suitable for the field of flexible spacecraft attitude control.

The invention relates to a strong interference resistance control method of a flexible spacecraft attitude control system, targeting a flexible spacecraft attitude control system having a nonlinear dynamic state, flexible vibration and measurement noise multi-source interference. The strong interference resistance control method of the flexible spacecraft attitude control system comprises steps of establishing a multi-source interference resistance model according to a nonlinear euler angle kinematics and posture dynamics of the flexible spacecraft to finish multi-source interference mathematic representation and modeling, designing an interference observer on the basis of mathematic representation and modeling to perform estimation on flexible vibration, designing an extended state observer to perform estimation on a system state and a non-linear dynamic state according to output of an interference observer, designing a strong interference resistance controller according to the interference observer and the extended state observer and solving an unknown gain on the basis of pole configuration to finish design of a strong interference resistance controller according to estimation values of the interference observer and the extended state observer. The strong interference resistance control method of the flexible spacecraft attitude control system is strong in interference resistance, high in control accuracy and can be applied to high accuracy control of the flexible spacecraft.

The invention discloses a flexible spacecraft active fault tolerant control method based on dynamic output feedback control, which belongs to the field of spacecraft attitude control. The method comprises the steps that a dynamic equation of a flexible spacecraft attitude control system is transformed into a general state space equation; a fault model with additive sensor measurement offset is established; a fault detection and identification module composed of an unknown input observer and a filter is established; real-time detection and on-line estimation are carried out on unknown sensor fault; and a fault tolerant controller based on dynamic output feedback is designed based on acquired fault estimation information. According to the invention, when a flexible spacecraft can normally reach an expected posture in the case of an additive sensor measurement offset fault; the influence of disturbance generated by modeling uncertainty and flexible accessory is considered in a design process; and a fault diagnosis and identification module and the fault tolerant controller can be independently designed, and can be easily realized by a project.