Dynamic Loading of an Aircraft Morphing Winglet
Bibliographic record
Abstract
View Video Presentation: https://doi.org/10.2514/6.2022-2573.vid This paper introduces an aircraft morphing winglet and associated dynamic loading system. The morphing winglet was designed as a two six-bar branch parallel mechanism that converted the horizontal actuation in the wingbox to the vertical rotation of the winglet for the cant angle change. The two-branch parallel mechanism formed an actuation redundant system that is compact yet sufficient to morph the winglet under the required aerodynamic load. The dynamic loading system was designed as a single four-bar linkage that was able to apply a simulated point load at the aerodynamic center and maintain its perpendicularity to the winglet surface mimicking the lift force during morphing. The dynamic loading system formed the second actuation redundant system. The entire system was actuated hydraulically under the standard aircraft supply pressure. Discussed in this paper is the method proposed for the implementation of the dynamic loading test for the developed morphing winglet. There were two main control challenges: i) synchronization of the two branches within the morphing mechanism and ii) synchronization of the morphing mechanism and the dynamic loading system. Different from the traditional optimal distributed redundant system control methods, we proposed a master-slave control strategy by assigning a branch as the leader (master) and another as the follower (slave). Through thorough mechanism design synthesis, we obtained a quasi-linear relation between the actuator’s strokes and the winglet angle as well as a quasi-constant relation between the stroke speed and the winglet angular velocity (rate of morphing). Through judicious calibration, the follower was able to accurately synchronize with the leader to morph the winglet together. To prevent force fighting between the two branches, the control system was designed with several feedback sensors including the encoders on the winglet for misalignment measurement and the strain gauges on the critical links for stress monitoring. A gain-scheduling feedback control law was implemented to account for the non-linearity inherent in the flow control valve. Furthermore, the control of dynamic loading system was integrated by adding a loadcell at the application point. Another gain-scheduling feedback control system was implemented for the load control with the goal to maintain the tension on the winglet all the time during morphing in either direction of cant up or cant down. The entire integrated control system was programmed using LabVIEW to have both on-site and remote-control functions. Three control methods were tested: i) pure position, ii) position-velocity, iii) position-velocity-load. The first control test showed that the morphing mechanism indeed provided a linear relation between the stroke inputs and the winglet angles. The second control test revealed that the same mechanism indeed provided a quasi-relation between the stroke speeds and the winglet angular velocity (rate of morphing). The third control test demonstrated that the morphing mechanism was able to sustain the required load to the full amount.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".