NV
N. Voß
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Quad-planes combine hovering and vertical takeoff and landing capability with fast and efficient forward flight. Regular Quad-planes with dedicated pusher motor can be subject to gust disturbances, and are not well-equipped to deal with actuator faults. Dual-axis Tilt-Rotor quad-planes are more maneuverable due to their overactuation. This also increases their gust resilience and allows them to hover statically after actuator failures. The vehicle in this paper uses an Incremental Nonlinear Dynamic Inversion (INDI ) controller, combined with a nonlinear Sequential Quadratic Programming (SQP) Control Allocation (CA ) algorithm, which can also find hover solutions in the case of actuator failures. We investigate both a combined allocation of linear and angular accelerations, as well as a cascaded allocation scheme. Due to large required changes in roll and pitch angles, the cascaded approach is selected in this research. Introduction of a tertiary control effort term, separation of attitude and actuator command optimization and a simulated Fault Detection and Identification ( FDI) mechanism led to repeated successful recovery from a motor failure in hover. Position tracking was demonstrated under failure in the recon- figured flight condition. Index Terms- Tilt-rotor, dual-axis tilt, quad-plane, FTC, over- actuated, control allocation
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Quad-planes combine hovering and vertical takeoff and landing capability with fast and efficient forward flight. Regular Quad-planes with dedicated pusher motor can be subject to gust disturbances, and are not well-equipped to deal with actuator faults. Dual-axis Tilt-Rotor quad-planes are more maneuverable due to their overactuation. This also increases their gust resilience and allows them to hover statically after actuator failures. The vehicle in this paper uses an Incremental Nonlinear Dynamic Inversion (INDI ) controller, combined with a nonlinear Sequential Quadratic Programming (SQP) Control Allocation (CA ) algorithm, which can also find hover solutions in the case of actuator failures. We investigate both a combined allocation of linear and angular accelerations, as well as a cascaded allocation scheme. Due to large required changes in roll and pitch angles, the cascaded approach is selected in this research. Introduction of a tertiary control effort term, separation of attitude and actuator command optimization and a simulated Fault Detection and Identification ( FDI) mechanism led to repeated successful recovery from a motor failure in hover. Position tracking was demonstrated under failure in the recon- figured flight condition. Index Terms- Tilt-rotor, dual-axis tilt, quad-plane, FTC, over- actuated, control allocation
Bachelor thesis
(2020)
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Y. Jannette Walen, T. Janz, L. Peschke, M. Rehbein, N. Voß, D.C. Saadeldin, C.P. Tranquille, M.M.M. D'Heer, L.C.J. Haagh, R.F.A. Wassenaar, M.C. Naeije, F.K. Leverone, J. Sinke, Henk Cruijssen
Assembly, Integration and Verification (AIV) in space makes launching geosynchronous satellites faster and significantly cheaper in the long term. A space-tug is launched into space to perform AIV there. It assembles a standardised satellite consisting of several modules. The modules are designed in such a way that the required subsystems for a communication satellite are incorporated in the modules. Examples of these modules are a propulsion module, a solar array module and a computer module. Due to the standardised modules, testing time and costs can be reduced significantly. This ensures a delivery time of maximum one year, which is the time from order until operations in space. The modules are efficiently packed and connected to external beams in the launch vehicle, to make sure that two satellites can be launched simultaneously. The external beams take up the extreme loads that occur during launch. This decreases the dry mass of the satellite, as the modules do not need as much structural mass. The subsystem design and structural analysis result in a drymass of 1847 kg per satellite. Next to the two satellites, a refuelling tank is added in the launch vehicle to refuel the tug. The tug requires 2921 kg of fuel to transfer the two satellites and go back to its initial state. Due to the modularity of the satellites, the lifetime of the satellites can be increased. Regarding the economic feasibility of the mission, a full return on investment is expected after 15 years of operations in base case scenario.
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Assembly, Integration and Verification (AIV) in space makes launching geosynchronous satellites faster and significantly cheaper in the long term. A space-tug is launched into space to perform AIV there. It assembles a standardised satellite consisting of several modules. The modules are designed in such a way that the required subsystems for a communication satellite are incorporated in the modules. Examples of these modules are a propulsion module, a solar array module and a computer module. Due to the standardised modules, testing time and costs can be reduced significantly. This ensures a delivery time of maximum one year, which is the time from order until operations in space. The modules are efficiently packed and connected to external beams in the launch vehicle, to make sure that two satellites can be launched simultaneously. The external beams take up the extreme loads that occur during launch. This decreases the dry mass of the satellite, as the modules do not need as much structural mass. The subsystem design and structural analysis result in a drymass of 1847 kg per satellite. Next to the two satellites, a refuelling tank is added in the launch vehicle to refuel the tug. The tug requires 2921 kg of fuel to transfer the two satellites and go back to its initial state. Due to the modularity of the satellites, the lifetime of the satellites can be increased. Regarding the economic feasibility of the mission, a full return on investment is expected after 15 years of operations in base case scenario.