Multicopter Flight Control After Rotor or Effector Failure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multicopters face challenges in controlled flight and safety due to effector failures, which can lead to catastrophic losses of control and crashes, especially in adverse conditions like wind and turbulence, limiting their operational effectiveness and reliability.
Innovation Solution
A method for controlling multicopters experiencing failures by estimating the orientation of a primary axis and angular velocity, allowing the remaining effectors to produce torque and thrust forces to maintain controlled flight, even with partial or complete loss of effector functionality, through a novel control scheme that enables rotation and translational motion control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multicopters use conventional control schemes with multiple effectors, then flight stability is maintained under normal conditions, but catastrophic failure occurs when one or more effectors malfunction
Solution Approach 1:
The control scheme dynamically adapts to effector failures by continuously monitoring effector performance and reconfiguring control commands in real-time. When failure is detected, the system transitions from conventional hover-capable control to a rotation-based control mode, dynamically adjusting the operational state of remaining effectors to maintain controlled flight.
Solution Approach 2:
The invention changes the fundamental control parameters from traditional thrust-vector control to rotation-based control. By causing the multicopter to rotate about a primary axis and using the remaining effectors to produce torques perpendicular to this axis, the system achieves translational motion control through parameter transformation rather than relying on multiple independently controllable effectors.
2Reliability
If multicopters are designed with effector redundancy (e.g., hexacopters, octocopters), then safety margin increases, but vehicle mass and design constraints increase
Solution Approach 1:
The invention extracts the safety function from structural redundancy (multiple effectors) and implements it through control system redundancy. Instead of requiring multiple effectors to provide safety margins, the system uses a sophisticated control algorithm that can maintain controlled flight with fewer effectors by adapting to failures and reconfiguring control commands.
Solution Approach 2:
The remaining effectors serve multiple functions simultaneously: they produce thrust for altitude control, generate torques for attitude control, and enable rotation-based translational motion. This multi-functionality allows the system to achieve the same safety margin as redundant designs without the additional mass.
3Reliability
If multicopters use effector encasement (shrouds, ducted fans) or parachutes for safety, then collision protection improves, but device complexity and design constraints increase
Solution Approach 1:
Instead of adding protective structures that prevent harm, the invention converts the potential harm of effector failure into a manageable condition through control system adaptation. The failure mode is transformed from catastrophic loss of control to a recoverable state where the multicopter can maintain controlled flight through rotation-based control schemes.
4Ease of operation
If multicopters rely on experienced human pilots for control, then operational flexibility is maintained, but cost-effectiveness and automation capability are limited
Solution Approach 1:
The multicopter performs self-diagnosis and self-reconfiguration when effector failures are detected. The control system automatically monitors effector performance, identifies failures, and reconfigures control commands without human intervention, enabling autonomous operation even in failure conditions. This self-service capability forms the foundation for full automation in diverse operating conditions.
Data Source
AI summary
According to a first aspect of the invention, there is provided a method for operating a multicopter experiencing a failure during flight, the multicopter comprising a body, and at least four effectors attached to the body, each operable to produce both a torque and a thrust force which can cause the multicopter to fly when not experiencing said failure. The method may comprise the step of identifying a failure wherein the failure affects the torque and/or thrust force produced by an effector, and in response to identifying a failure carrying out the following steps, (1) computing an estimate of the orientation of a primary axis of said body with respect to a predefined reference frame, wherein said primary axis is an axis about which said multicopter rotates when flying, (2) computing an estimate of the angular velocity of said multicopter, (3) controlling one or more of said at least four effectors based on said estimate of the orientation of the primary axis of said body with respect to said predefined reference frame and said estimate of the angular velocity of the multicopter. The step of controlling one or more of said at least four effectors may be performed such that (a) said one or more effectors collectively produce a torque along said primary axis and a torque perpendicular to said primary axis, wherein (i) the torque along said primary axis causes said multicopter to rotate about said primary axis, and (ii) the torque perpendicular to said primary axis causes said multicopter to move such that the orientation of said primary axis converges to a target orientation with respect to said predefined reference frame, and (b) such that said one or more effectors individually produce a thrust force along said primary axis.