Mitsubishi Electric Corporation

Takeya Shima

Kenji Kitamura

Katsuhiko Yamada

Hiroshi Suenobu

In an orbital attitude control device (), an ideal thrust axis direction calculator () calculates an ideal thrust axis direction based on information of a predetermined orbit, an ideal attitude calculator () calculates an ideal attitude of the satellite based on the ideal thrust axis direction and a solar direction, and a control torque calculator () calculates an ideal control torque that makes the attitude of the satellite follow the ideal attitude and a torque restraint plane in which the solar direction is orthogonal to a rotational axis of the solar array panel, defines an evaluation function obtained by weighting a distance from the ideal control torque and a distance from the torque restraint plane and then summing the weighted distances, and calculates the control torque that allows the drive constraint to be satisfied and the evaluation function to be minimized.

Orbital attitude control device, satellite, orbital attitude control method, and recording medium

An attitude control apparatus () includes an ideal thrust direction calculator (), an ideal attitude calculator (), a target attitude calculator (), and a torque calculator (). The ideal thrust direction calculator () calculates an ideal thrust direction of a thruster. The target attitude calculator () calculates a target attitude that is the attitude of a satellite in which a deviation from an ideal attitude is minimized within a movement limitation of an attitude control actuator () while a panel surface faces the sun. The torque calculator () calculates a torque for turning the satellite from an actual attitude to the target attitude and transmits a torque instruction to the attitude control actuator ().

Orientation control device, satellite, orientation control method, and program

When calculating a gimbal angle trajectory that satisfies boundary conditions set by an attitude boundary condition setterof the ground station, a gimbal angle trajectory calculatorcalculates the gimbal angle trajectory that minimizes a period of an acceleration interval within a range that satisfies driving restrictions of a gimbal, based on a gimbal angle &#x3b8;of a start time and a gimbal angle &#x3b8;of a fixed interval of an attitude change. Also, the gimbal angle trajectory is calculated that minimizes a period of a deceleration interval within a range that satisfies the driving restrictions of the gimbal, based on the gimbal angle &#x3b8;of the fixed interval and a gimbal angle &#x3b8;of a completion time of the attitude change. The obtained &#x3b8;, &#x3b8;, &#x3b8;and an attitude change period &#x3c4; are transmitted to the artificial satellite as gimbal angle trajectory parameters, and the control moment gyros are controlled based on the gimbal angle trajectory parameters.

Artificial satellite, attitude control system, and attitude control method

A satellite comprises thrusters disposed with the firing directions each facing away from the mass center of satellite and different from each other. A control amount calculator calculates control amounts of the mean orbital elements from the mean orbital elements and the temporal change rates of the mean orbital elements set by an orbit determiner, and the target values. A distributor calculates firing timings and firing amounts of the thrusters for realizing the control amounts of the mean orbital elements by expressing a motion of satellite with orbital elements, solving an equation taking into account coupling of an out-of-plane motion and an in-plane motion due to thruster disposition angles and thruster firing amounts at multiple times, and combining one or more thruster firings controlling mainly an out-of-the-orbit-plane direction and one or more thruster firings controlling mainly an in-the-orbit-plane direction.

Orbit control device and satellite

When the number of CMGs is represented by n (n is an integer of 4 or more), (n&#x2212;3) gimbal angles out of n gimbal angles corresponding to the n CMGs are set as free parameters, and an algebraic equation representing a relationship among three gimbal angles out of the n gimbal angles, the free parameters, and an angular momentum of all the CMGs is used to solve the algebraic equation while changing the free parameters within set ranges, to thereby obtain solutions of the gimbal angles of the plurality of CMGs required for achieving a given angular momentum.

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Chiyoda-ku, Japan

Takeya Shima