Danil Sergeevich Ivanov

Testing of attitude control algorithms for microsatellite Chibis-M at laboratory facility

A laboratory facility developed at the Engineering Technological Center “Scan Ex” for testing algorithms for determination of attitude and stabilization of the attitude system of the satellite “Chibis-M” is described. The results of experiments on damping initial angular rotation, using magnetorquers, stabilization of the mock-up using flywheels, and flywheel unloading are analyzed. The operation of the algorithm for determination of the mock-up attitude is studied; the main characteristics of this algorithm are the accuracy of the state vector estimation and the time of convergence.

Laboratory study of magnetic properties of hysteresis rods for attitude control systems of minisatellites

Results of the experimental determination of the parameters of hysteresis rods made of soft magnetic materials used in passive attitude control systems to damp the perturbed motion of satellites relative to their center of mass are described. Based on the classical solution of the linear magnetization problem and an approximate solution of the problem of nonlinear magnetization in a variable magnetic field, it is shown that the considerable distortion in the experimental determination of the parameters is explained by eddy currents induced in the rods. To mitigate the effect of those currents, it is shown that the measurements must be performed when the frequency of the magnetic fields variation is not higher than 0.1–0.2 Hz. Using nonlinear magnetization theory, a procedure for the experimental determination of the parameters of hysteresis rods is developed. This procedure is augmented by the corresponding computer processing of weak valid signals. The procedure can be used for the choice of the parameters of damping devices included in satellite passive attitude control systems.

Attitude control of a rigid body suspended by string with the use of ventilator engines

Axial motion of a balloon payload with respect to the center of mass under action of ventilator engines is studied. An implementation of a control algorithm is suggested. The possibility of using ventilator engines for trajectory tracking is examined. A technique for determining engine parameters and results of laboratory tests of a system mock-up are presented.

Laboratory Facility for Microsatellite Mock-up Motion Simulation

A description of a COSMOS laboratory facility for the controlled motion simulation of microsatellites created in Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences and the results of its application to the simulation of the control algorithms are presented. The laboratory facility consists of an aerodynamic table and microsatellite mock-ups. Due to the air cushion between the table surface and the disks on which the mock-ups are installed, free motion with three degrees of freedom becomes possible: two translational and one rotational. A review of the simulator’s international analogues has revealed its advantages and disadvantages. A motion determination algorithm based on video processing is described and its accuracy is studied. The results of the investigation of perturbations acting on the mock-ups on the aerodynamic table are presented. The performance of the control algorithms is demonstrated.

Satellite relative motion determination during separation using image processing

Satellite relative position and attitude determination algorithm by video processing is developed. The algorithm is numerically simulated and studied. Relative state determination accuracy depending on a distance and pre-defined points image size is investigated. Microsatellite ‘Chibis-M’ and spaceship ‘Progress-13M’ relative motion after separation is determined by the algorithm.

Formation-Flying Momentum Exchange Control by Separate Mass

A, B = amplitudes for Cauchy problem, m a, b = arbitrary constants for circular trajectory, m C1 : : : C6 = arbitrary constants for Cauchy problem, m K, L, M, N = parameters of error ellipsoid k = ratio of masses of additional body to the satellite m = mass, kg R = position in presence of errors, m R = acceptable error, m r = satellite/additional body position in orbital reference frame x; y; z , m s, u = angular variables t = time, s te = time of mass ejection, s tm = time of mass hit, s v = satellite/additional body velocity, m∕s Δ = determinant in boundary value problem δv = δ _ x; δ _ y; δ_ z relative velocity of mass separation, m∕s e = error μ = gravitational parameter of the Earth ρ = radius of circular orbit, m Φ1, Φ2, Φ3 = minimizable functions φ, ψ = phases for Cauchy problem ω = orbital angular velocity, 1∕s