30 results about "Periodic orbits" patented technology

A dynamic servo control method of an under-actuated mechanical device ACROBOT relates to a dynamic servo control method of an under-actuated mechanical system, and aims at solving the problems of single application field and narrow research field of the existing under-actuated systems. The method comprises the following steps: obtaining instantaneous state quantities of pivot angles of a connecting rod and a pendulum rod from the under-actuated mechanical system to compute a pivot angle error; obtaining a state variable of the current pivot angle of the pendulum rod; obtaining a model time-variant parameter in a feedback control law; obtaining mechanical energy of the under-actuated mechanical system and comparing the mechanical energy with a given value to obtain a target error; and substituting the data into a feedback control law formula to obtain a control torque which is required now, and outputting the control torque to the mechanical system by a motor. In the method, the dynamic servo control is achieved by constructing a Lyapunov function, and a large-scale motion control of the under-actuated system is achieved by constructing a periodic orbit similar to a motion track of a single pendulum which takes the peak of the orbit as the target point, and by stabilization control of a balance point and follow-up control of a special track.

The invention discloses a method of lorentz force multi-star formation configuration based on a quasi-periodic orbit, and belongs to the field of aerospace. According to the method of lorentz force multi-star formation configuration based on the quasi-periodic orbit, the implementation method includes the steps that motion equations of charged slave stars under an artificial magnetic field of a host star are established, the motion equations are subjected to dimensionless simplification treatment, an equilibrium point of the dimensionless motion equations is determined, periodic orbits near the equilibrium point are obtained by using a differential correction method and a numerical continuation method, the quasi-periodic orbit on the central manifolds of the periodic orbits is calculated,and by deploying a plurality of charged satellites on invariant curves under stroboscopic mapping of the quasi-periodic orbit, lorentz force multi-star formation configuration without working medium consumption is realized. According to the method of lorentz force multi-star formation configuration based on the quasi-periodic orbit, chemical fuel is not required to be consumed, chemical pollutionis avoided, and application prospects are achieved in close distance space formation, in-orbit operation and long time space observation tasks. The method of lorentz force multi-star formation configuration based on the quasi-periodic orbitis is suitable for the charged satellites to conduct close distance formation around a spacecraft with a self-spinned magnetic field on an earth high orbit.

In a rotary encoder of the present invention, each track of a rotary disk has transmitting parts and non-transmitting parts alternately arranged in the circumferential direction. Each non-transmitting part has a plurality of projecting parts which are arranged side by side in the circumferential direction. Each projecting part has a pair of reflecting surfaces which retro reflect incident light toward a light emitting part. A plurality of tracks include a periodic track where transmitting parts and non-transmitting parts are arranged with a periodic pattern and non-periodic tracks where transmitting parts and non-transmitting parts are arranged in a non-periodic pattern. The periodic track and non-periodic track are respectively arranged at positions in the radial direction where further reflected light at the light emitting part after retro reflection at the reflecting surfaces of the non-periodic track will not enter the periodic track.

The invention discloses a method for searching an instable periodic orbit of a chaotic switching converter, and the method continuously correct a former hypothetical result for the characteristics of the harmonic components of the instable periodic orbit according to the characteristic that a chaotic nonlinear system has periodic traversal through the assumption of the amplitude values of harmonic components of the orbit, the combination of a disturbance method and the principle of harmonic balance and the characteristics of the harmonic components of an inductance / current continuous mode DC-DC switcher at a chaotic state, and finally obtains an analytical expression of the instable periodic orbit relative to a chaotic attractor. The method provides a new idea for the searching of the instable period -n orbit in the inductance / current continuous mode DC-DC switcher at a chaotic state. Because the method is based on the principle of harmonic balance, the obtained instable periodic orbit expression can clearly reflect the harmonic components in the orbit, and can provide design basis for a chaotic controller based on a notching filter / delay feedback.

The invention relates to a method for calculating a stable orbit of a non-synchronous binary star system, in particular to a method for calculating the stable orbit of the non-synchronous binary star system based on second-order differential correction, belongs to the field of aerospace technologies and is suitable for orbit design for detection of the non-synchronous binary star system by a detector. For an arbitrary non-synchronous binary star system, the system is firstly considered as a synchronous system for periodic orbit searching; then the synchronous system is converted into a non-synchronous system according to a spin period of minor planets, and the obtained periodic orbit is divided into a plural sections according to an orbital period; the plural sections of the periodic orbit are introduced into the non-synchronous system for orbit integral; the plural sections of the orbit are respectively subject to position correction and speed correction; and the long-term stable orbit in the non-synchronous system is obtained through multiple iterations. The stable orbit suitable for the non-synchronous binary star system can be realized, an initial value of the orbit is easy to select and good in convergence, and the calculation efficiency is high.

A method for maintaining the periodic orbit of the hybrid sail of the Earth-Moon system based on a disturbance observer, including steps: 1) Establishing the relative motion dynamics equation of the hybrid sail orbit of the Earth-Moon system in the Earth-Moon system's rendezvous coordinate system; 2) In the Earth-Moon system In the CRTBP model, a disturbance force model is established for the eccentricity of the lunar orbit and the gravitational disturbance of the sun; 3) determine the linear period state feedback rate, and design the orbit maintainer with the optimal period; 4) design a nonlinear disturbance observer to make the nonlinear disturbance observation 5) According to the changing law of the mass of the hybrid sail, the particle swarm optimization algorithm is used to optimize the acceleration of the electric propulsion. The orbit keeper with the optimal period of the invention has the advantages of simple structure and strong robustness, and the nonlinear disturbance observer can improve the orbit keeping accuracy. The invention reduces fuel consumption of the electric propulsion system and prolongs the working life of the system.

The invention provides a control method of a periodic orbit near a collinear Lagrange point. A collinear Lagrangian point belongs to a hyperbolic equilibrium point, and the dynamic characteristic of the collinear Lagrangian point is strongly disturbed by a high-order nonlinear term of a system, so that periodic orbits nearby the collinear Lagrangian point are unstable. Due to the influence of orbit injection errors and external disturbance, the spacecraft cannot meet the precise solution of a periodic orbit all the time, and is constantly away from the Lagrange point under the uncontrolled condition. According to the invention, the idea of the differential correction algorithm is applied to the Hamiltonian structure controller, the control gain is corrected according to the given initial position speed of the spacecraft, and an effective control algorithm is provided to ensure that the spacecraft flies around the controlled period orbit in a bounded manner near the collinear Lagrange point. According to the differential correction algorithm, the initial position speed of the spacecraft does not need to be corrected, and the periodic orbit can be constructed under the condition that the initial position speed of the spacecraft is not required to be high in precision.

The invention relates to a double-asteroid system periodic orbit searching method based on the speed Poincare section and belongs to the field of aerospace. The method comprises the following steps that 1, the mass and size of each asteroid are obtained and are normalized; 2, a system rotating coordinate system is built; 3, the searching range is selected, the initial position of a detector is selected in the X-axis direction, the initial speed is gradually increased, orbit integration is carried out, the stopping condition is that the detector penetrates through the predetermined section, and then a Poincare map is drawn according to the speed at the termination point; 4, two adjacent initial points, penetrating through the axis, in the curve in the map are selected, an initial state average value is obtained to be subjected to integration again, a new initial point penetrating the axis is obtained, repeated iteration is carried out, and an accurate value is obtained; 5, the initial position of the detector is changed, and the third step and the four step are carried out repeatedly until the values cover the searching area. Compared with the prior art, the method has the advantages of being high in efficiency, comprehensive in searching, simple in calculation and the like, and is suitable for orbit design occasions where the detector detects a double-asteroid system.

The invention discloses an upper sage multi-satellite deployment full task periodic orbit designing method. The method includes the following steps: 1. based on an upper stage multi-satellite deployment task, presenting general procedures of multi-satellite deployment, analyzing the composition of phase error of multi-satellite deployment; 2. Conducting error compensation on the phase error of which the composition has been analyzed and the phase error which is caused by orbit perturbation, satellite separation and orbit maneuver, then designing a drift orbit; and 3. Considering phase error which is caused by other interference factors in the phase drift process, conducting intermediate correction in the phase maneuver. The method herein, by fully considering all kinds of error compositions and factors in the process of multi-satellite deployment, designs the parameters of an upper stage drift orbit on the basis of compensating respective phase errors, and by conducting intermediate correction in the phase maneuver based on the limited threshold values, further effectively suppresses phase error, and increases the effects of realizing multi-satellite deployment and initial performances of the constellation that is deployed.

The invention discloses a position selection method for observing and tracking a small body based on a Sun-Earth libration point, which belongs to the technical field of aeronautics and astronautics. The method comprises the following steps of: acquiring five dynamic libration points by a three-body system consisting of space observation spacecrafts, the Sun and the Earth; selecting a qusi-periodic orbit near the L2 point as the location point of the first space observation spacecraft; and selecting the L4 point and the L5 point as the location points of the second space observation spacecraft and the third space observation spacecraft so as to construct the observation network of the three space observation spacecrafts to observe and track the small body in combination. In comparison to the prior art, the method provided by the invention can observe and track the small body for a long period, and has the advantages of good stability, less energy consumption for keeping the positions of the spacecrafts, long observation and tracking arc segments, and so on.

The invention discloses an upper sage multi-satellite deployment full task periodic orbit designing method. The method includes the following steps: 1. based on an upper stage multi-satellite deployment task, presenting general procedures of multi-satellite deployment, analyzing the composition of phase error of multi-satellite deployment; 2. Conducting error compensation on the phase error of which the composition has been analyzed and the phase error which is caused by orbit perturbation, satellite separation and orbit maneuver, then designing a drift orbit; and 3. Considering phase error which is caused by other interference factors in the phase drift process, conducting intermediate correction in the phase maneuver. The method herein, by fully considering all kinds of error compositions and factors in the process of multi-satellite deployment, designs the parameters of an upper stage drift orbit on the basis of compensating respective phase errors, and by conducting intermediate correction in the phase maneuver based on the limited threshold values, further effectively suppresses phase error, and increases the effects of realizing multi-satellite deployment and initial performances of the constellation that is deployed.

The invention discloses a method for precise detection and orbit transfer of low-energy small celestial bodies under complex constraints, which belongs to the field of aerospace technology. The present invention firstly determines the multiple complex non-uniform strong coupling constraints that must be satisfied by the detection track design task, and establishes the mapping relationship between the multiple complex non-uniform strong coupling constraints and the track design parameters; establishes the dynamic equation of the detector under the centroid rotating coordinate system ; The initial value is provided by the established linearized detector dynamic equation, and the accurate quasi-periodic orbit under the ephemeris model is obtained by using the nonlinear dimensionality reduction method and the second-order differential correction; based on the accurate quasi-periodic orbit under the ephemeris model, the The initial value of the transfer orbit is obtained by optimization of the manifold perturbation method; the initial value of the transfer orbit is corrected according to a variety of complex non-uniform strong coupling constraints, and an accurate low-energy transfer orbit is obtained. The invention has the advantages of high efficiency, good convergence and less energy required for transfer.

The present invention relates to a DC-DC converter chaos control method, system and medium based on super-twisting control. The method includes mathematical modeling of the DC-DC converter to obtain the chaos model of the state variable of the DC-DC converter Obtain the chaotic energy storage value in the chaotic state in the chaotic model, obtain the energy storage constant value in the steady state in the chaotic model according to the chaotic energy storage value, and according to the chaotic energy storage value and the storage The error variable can be determined by a constant value; based on the super twist control method, an estimated error amount is obtained according to the error variable, and an equivalent sliding mode controller is designed according to the error variable and the estimated error amount to obtain the equivalent A control signal of a sliding mode controller; the DC-DC converter is controlled according to the control signal. The present invention can effectively control the DC-DC converter in the chaotic state to orbit in the 1-period state, effectively eliminate the chaotic phenomenon, have faster dynamic response, stronger robustness, and lower voltage ripple.

The invention discloses a method of lorentz force multi-star formation configuration based on a quasi-periodic orbit, and belongs to the field of aerospace. According to the method of lorentz force multi-star formation configuration based on the quasi-periodic orbit, the implementation method includes the steps that motion equations of charged slave stars under an artificial magnetic field of a host star are established, the motion equations are subjected to dimensionless simplification treatment, an equilibrium point of the dimensionless motion equations is determined, periodic orbits near the equilibrium point are obtained by using a differential correction method and a numerical continuation method, the quasi-periodic orbit on the central manifolds of the periodic orbits is calculated,and by deploying a plurality of charged satellites on invariant curves under stroboscopic mapping of the quasi-periodic orbit, lorentz force multi-star formation configuration without working medium consumption is realized. According to the method of lorentz force multi-star formation configuration based on the quasi-periodic orbit, chemical fuel is not required to be consumed, chemical pollutionis avoided, and application prospects are achieved in close distance space formation, in-orbit operation and long time space observation tasks. The method of lorentz force multi-star formation configuration based on the quasi-periodic orbitis is suitable for the charged satellites to conduct close distance formation around a spacecraft with a self-spinned magnetic field on an earth high orbit.

The invention discloses a method for generating chaos based on pulse control. The steps include: step 1: building a model of a controlled nonlinear system; step 2: building a single-variable pulse controller; step 3: using the pulse of the single-variable pulse controller The interval and state feedback pulse gain are the analysis objects, draw the parameter bifurcation diagram of the controlled dynamic system, use the parameter bifurcation diagram to obtain the parameter range corresponding to the chaos, and select the pulse controller parameters that make the controlled nonlinear system generate chaos; Step 4: Analyze the state of the controlled nonlinear system under the selected control parameters to verify the chaotic characteristics. If the chaotic characteristics are not satisfied, go back to step 3 and reselect the pulse control parameters in the chaotic parameter area; otherwise, end all steps. In the method of the invention, the control energy is smaller than that of the continuous control chaos generation method, the chaos generation area is not limited to the vicinity of the periodic orbit of the original stable system, the chaos can be generated and the chaos can be eliminated, and the flexibility is better.

The invention discloses a planet low-energy orbit capture method based on a balance point and a periodic orbit, and relates to an orbit capture method, and belongs to the technical field of aerospace. The method uses characteristics of a balance point, a periodic orbit, and invariant manifold in a sun-plant-detector three-body system to realize capture of a detector by a planet. The method comprises: firstly, applying first engine driving at height of a pericenter which is relatively low relative to the planet, to enter a stable manifold in the three-body system, and sliding to the periodic orbit without power along the manifold, using the orbit as a parking orbit; then using an unstable manifold of the periodic orbit to get close to the planet, selecting an unstable manifold whose pericenter height is the same with that of a target orbit, and applying second engine driving when reaching the pericenter, to realize planet capture. Speed increment required by the method is low, flexibility is high, and the method is suitable for orbit capture of different planets. By using the characteristic of the periodic orbit, the planet can be observed in a capture process, so as to increase data of planet observation in a detection task.

A dynamic servo control method of an under-actuated mechanical device ACROBOT relates to a dynamic servo control method of an under-actuated mechanical system, and aims at solving the problems of single application field and narrow research field of the existing under-actuated systems. The method comprises the following steps: obtaining instantaneous state quantities of pivot angles of a connecting rod and a pendulum rod from the under-actuated mechanical system to compute a pivot angle error; obtaining a state variable of the current pivot angle of the pendulum rod; obtaining a model time-variant parameter in a feedback control law; obtaining mechanical energy of the under-actuated mechanical system and comparing the mechanical energy with a given value to obtain a target error; and substituting the data into a feedback control law formula to obtain a control torque which is required now, and outputting the control torque to the mechanical system by a motor. In the method, the dynamic servo control is achieved by constructing a Lyapunov function, and a large-scale motion control of the under-actuated system is achieved by constructing a periodic orbit similar to a motion track ofa single pendulum which takes the peak of the orbit as the target point, and by stabilization control of a balance point and follow-up control of a special track.