On the feasibility of applying robot vision to proximity extraction based on one camera in space

Existing robot vision algorithms are evaluated for application in space for proximity extraction using one camera. Lighting conditions and image formation differ from earth conditions which have implications. An algorithm is derived which is based on the use of run coding, tracking and a least mean error method. Problems concerning hardware...

GOCE Spacecraft Attitude Control: A magnetic attitude controller simulator

Given the difficulty that is normally associated with tuning highly nonlinear control systems, such as seen in LEO spacecraft, it is interesting to evaluate how new controller types perform. The measured data from the GOCE mission has led to the creation of high fidelity torque models describing the angular perturbations acting on a spacecraft....

Magnetorquer Design and Attitude Control for SHAPE

Designing and modelling a magnetorquer, and developing an attitude control loop, with magnetorquers as only actuators, for the Stable and Highly Accurate Pointing Earth-Imager (SHAPE), which has a huge momentum wheel for stabilization and flies in a very low Earth orbit.

Development of a Robust and Combined Controller for On-Orbit Servicing Missions

Nowadays, a satellite is considered as out of range forever once it is launched. This may soon no longer hold thanks to on-orbit servicing. However, the complexity of that topic makes it highly challenging on many aspects. On-orbit servicing using a robotic arm is nonetheless the most investigated technology in order to achieve the berthing of...

Attitude Control of Flexible Spacecraft: Design, implementation and evaluation of control strategies targeting flexible structures in the space domain, based in an analytical modeling of these structures

During the last decades, large deployable structures are starting to be seen as a plausible configuration to multiple space missions, such as solar sailing, LEO (Low Earth Orbit) deorbiting missions or solar power generation. Technological advances in key areas, such as thin film solar cells or new deployment methods, as well as the...

Precise control of LISA with Quantitative Feedback Theory

The Laser Interferometer Space Antenna (LISA) is a European mission for the detection of gravitational waves in space set to be launched in 2034. The mission will see the deployment of 3 spacecraft in heliocentric orbit keeping a triangular formation with side length of 2.5 million km. Laser beams are exchanged between the spacecraft by means of...

Optimal scheduling for agile Earth observation satellites

The past decade has seen a continuous increase of Earth observation missions, since they are regarded as an important tool to address global problems such as climate change or disaster mitigation. A commercial trend exists now towards higher resolution imagery, which drives the use of agile satellites. Nevertheless, a disadvantage of agile...

Incremental Nonlinear Fault-Tolerant Control of a Quadrotor With Complete Loss of Two Opposing Rotors

In order to further expand the flight envelope of quadrotors under actuator failures, we design a nonlinear sensor-based fault-tolerant controller to stabilize a quadrotor with failure of two opposing rotors in the high-speed flight condition (>8 m/s). The incremental nonlinear dynamic inversion approach which excels in handling model...

Robustifying dynamic positioning of crane vessels for heavy lifting operation

Construction crane vessels make use of dynamic positioning (DP) systems during the installation and removal of offshore structures to maintain the vessel's position. Studies have reported cases of instability of DP systems during offshore operation caused by uncertainties, such as mooring forces. DP “robustification” for heavy lift operations...

Distributed Coordinated Control for Fixed-Wing UAVs with Dynamic Event-Triggered Communication

Compared with most existing results concerning unmanned aerial vehicles (UAVs) wherein two-degree or only attitude/longitudinal dynamics are considered, this paper proposes an event-based fault-tolerant coordinated control (FTC) for multiple fixed-wing UAVs such that the consensus tracking of velocity and attitude is achieved in the presence...

Event-Triggered Adaptive Fault-Tolerant Synchronization Tracking Control for Multiple 6-DOF Fixed-Wing UAVs

In contrast with most existing results concerning unmanned aerial vehicles (UAVs) wherein two-degree or only attitude/longitudinal dynamics are considered, this article proposes an event-triggered cooperative synchronization fault-tolerant control (FTC) methodology for multiple fixed-wing UAVs whose dynamics are six-degree-of-freedom (DOF)...

Multi-Objective Cooperative Control for a Ship-Towing System in Congested Water Traffic Environments

This paper proposes a multi-objective cooperative control method for a ship-towing system in congested water traffic environments. The control objectives are to coordinate multiple autonomous tugboats for transporting a ship to: (i) follow the waypoints, (ii) adjust the heading, (iii) track the speed profile, and (iv) resolve collisions. The...

Attitude & orbital control system design for near-Earth asteroid exploration using autonomous miniature satellites

The thesis explores designing an attitude and orbital control system for an autonomous 6U CubeSat near-Earth asteroid fly-by mission, aiming to conceptualize an off-the-shelf solution. It addresses selecting propulsion systems for interplanetary travel, reaction wheel desaturation, and attitude control during the mission.<br/><br/>Through a fuel...