scholarly journals Coarse Alignment of Marine Strapdown INS Based on the Trajectory Fitting of Gravity Movement in the Inertial Space

Sensors ◽  
2016 ◽  
Vol 16 (10) ◽  
pp. 1714 ◽  
Author(s):  
Lin Zhao ◽  
Dongxue Guan ◽  
Jianhua Cheng ◽  
Xiaomin Xu ◽  
Zaihui Fei
Keyword(s):  
Inertial Space

Control of following Force in Gimbal Suspension by Programmed Transfer of Vehicle in the Class of Spiral-Screw Trajectories

2020 ◽  
Vol 8 (6) ◽  
pp. 01-15
Author(s):  
Kravets V.V ◽  
Kravets Vl.V ◽  
Artemchuk V.V.
Keyword(s):  
Mathematical Models ◽  
Reference System ◽  
Driving Force ◽  
Reference Systems ◽  
Structural Scheme ◽  
Inertial Space ◽  
Transport Vehicle ◽  
Terrestrial Reference System ◽  
Force Components ◽  
Speed Mode

The programmed transfer of the transport vehicle in space is carried out in the class of helical trajectories, using forcing (throttling) and deviation of the following driving force in the gimbal. The paper introduces the mathematical models of the transport vehicle kinetics in space in the terrestrial reference system and in the basis of the natural trihedral of the trajectory, using the quaternion form. The kinematics of the transport vehicle in the fixed and mobile reference systems, as well as the orientation of the natural trihedral in the inertial space, are represented by the hodograph of the program helix trajectory in vector and quaternion forms. The components of the controlling driving force in the basis of the natural trihedral are determined by the kinetostatics equations of the programmed transfer of the transport vehicle along a helical trajectory in the required speed mode. The authors proposed a structural scheme of the gimbal suspension, providing the required driving force components. The authors considered two possible sequences of rotations of the moving gimbal rings and demonstrated their equivalence. Laconic formulas are established for the control angles of rotation of the moving gimbal rings.

Control of the Hydrofoil Ship

1967 ◽  
Vol 20 (03) ◽  
pp. 292-303 ◽  
Author(s):  
P. Magini ◽  
J. Burroughs
Keyword(s):  
Relative Position ◽  
Water Surface ◽  
Hydrodynamic Pressure ◽  
Inertial Space ◽  
Pressure Centre ◽  
Sea Transportation ◽  
The Subject ◽  
The Moment ◽  
Control Surfaces ◽  
Righting Moment

Modern hydrofoil ships have evolved in response to the need for a fast reliable means of sea transportation which is capable of operating in all sea conditions. It is the purpose of this paper to describe how the application of modern stabilization and navigation technology to hydrofoil ships has contributed to the achievement of these goals.First, consider the subject of stability. In particular, consider the source of roll stability in three types of ships: a displacement ship; a surface piercing hydrofoil and a submerged-foil hydrofoil. A roll disturbance of each of the ships is depicted in Fig. 1. In both the displacement ship and in the surface piercing hydrofoil, the righting moment is produced entirely by the change in attitude of the ship relative to the water surface. In the case of the displacement ship, the righting moment is due to the shift of the centre of buoyancy. For the surface piercing hydrofoil, the moment occurs due to the shift of the hydrodynamic pressure centre of the foils. However, for the submerged-foil hydrofoil, no righting moment is produced by the change of the relative position of the water surface. The righting moment for this ship must be produced by underwater control surfaces in response to the change of ship attitude relative to inertial space, as sensed by a vertical gyro. It is this transfer of stability reference from the water surface to an inertial reference that leads to the superior seakeeping capabilities of the submerged foil hydrofoil.

Impedance Control of Free-Flying Space Robot for Orbital Servicing

2006 ◽  
Vol 18 (5) ◽  
pp. 608-617 ◽  
Author(s):  
Hiroki Nakanishi ◽  
◽  
Kazuya Yoshida
Keyword(s):  
Control Method ◽  
Impedance Control ◽  
Space Robot ◽  
Space Manipulator ◽  
Inertial Space ◽  
Mass Damper ◽  
Fixed Base ◽  
Manipulator Arm ◽  
Spring System ◽  
Target Satellite

One of the most important phases of orbital servicing by a space robot is capturing a target satellite. In this phase, there is the risk that contact will push the target and robot away from each other. Controlling the impedance of the manipulator effectively prevents this. For a free-flying space robot, however, conventional methods used for fixed base robots cannot be used because the motion of the base interferes with the manipulator motion. An impedance control method for a space manipulator arm is proposed, where the end tip of the manipulator is controlled as if a mass-damper-spring system fixed in inertial space. Possible applications in orbital servicing are also discussed.

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