Pivotable Propulsion Control Under Thrust Saturation in Aerial Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aerial vehicles with pivotable propulsion units face challenges in maintaining flight safety while maintaining a compact and lightweight configuration, as existing designs require heavy propulsion units and actuators to handle all possible translational and rotational movement commands, leading to potential saturation and instability.
Innovation Solution
A method of operating aerial vehicles where the angular position and thrust force of propulsion units are controlled by prioritizing rotational movement commands over translational movement commands, adjusting the translational movement commands in degrees of freedom to prevent saturation, allowing the vehicle to maintain stability and desired attitude even in extreme conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If propulsion units and actuators are designed to handle all possible translational and rotational movement commands, then flight safety is improved, but vehicle weight increases
Solution Approach 1:
The patent implements dynamic command adjustment where the control system continuously monitors propulsion unit saturation status and adaptively modifies translational movement commands in real-time. This allows the system to maintain flight safety with lighter actuators by dynamically adapting to operational constraints rather than designing for maximum static capacity
Solution Approach 2:
The control system changes operational parameters by adjusting translational movement commands based on saturation detection. When saturation is detected in angular position or thrust force, the system modifies the translational command parameters to prevent exceeding actuator limits, enabling lighter actuator design while maintaining safety
2Reliability
If propulsion units are designed with high capacity to handle extreme conditions, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent employs feedback control by continuously monitoring the angular position and thrust force of propulsion units, detecting saturation conditions, and adjusting translational movement commands accordingly. This feedback mechanism enables reliable operation with simpler propulsion units by actively managing operational constraints
Solution Approach 2:
The control system performs preliminary saturation detection and command adjustment before the propulsion units actually exceed their limits. By proactively modifying translational commands when saturation is anticipated, the system prevents extreme conditions without requiring oversized propulsion units
3Productivity
If translational movement commands are maintained at full authority, then productivity is improved, but stability deteriorates due to saturation
Solution Approach 1:
The patent applies partial action by adjusting translational movement commands to a reduced level when saturation is detected. Instead of maintaining full authority commands that would cause instability, the system selectively reduces translational command magnitude in affected degrees of freedom while preserving rotational control authority
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A method of operating an aerial vehicle (1), the aerial vehicle (1) comprising a plurality of propulsion units (4, 5) arranged to be pivotable about at least one axis along an angular position and configured to generate a thrust force and/or a lift force, wherein the angular position and/or the thrust force of the plurality of propulsion units (4, 5) are controlled based on a translational movement related command, in particular, a force command, of the aerial vehicle (1) regarding at least one degree of freedom and a rotational movement related command, in particular, a moment command of the aerial vehicle (1) regarding at least one degree of freedom. In order to ensure flight safety, if it is determined that a combination of the translational movement related command and the rotational movement related command causes a saturation in the angular position and/or the thrust force of at least one of the plurality of propulsion units (4, 5), the translational movement related command is adjusted in at least one degree of freedom such that the rotational movement related command is met.