Three-dimensional(3D)profile scanning plays a crucial role in the inspection of assembled large aircraft.In this paper,to achieve noncontact automatic measurements of the high-reflective profiles of large-scale curved...Three-dimensional(3D)profile scanning plays a crucial role in the inspection of assembled large aircraft.In this paper,to achieve noncontact automatic measurements of the high-reflective profiles of large-scale curved parts and components,an automated noncontact system and method with high accuracy and high efficiency are presented.First,a hybrid 3D coordinate measurement system based on proximity sensors and cameras is proposed to obtain noncontact measurements while avoiding the influence of high reflection on the measurement accuracy.A hybrid measurement model that combines the one-dimensional distances measured by the proximity sensors and the 3D information obtained by cameras is proposed to determine high-accuracy 3D coordinates of the measured points.Then,a profile-driven 3D automated scanning method and strategy are designed to rapidly scan and reconstruct the profile within the effective range without scratching the profile or exceeding the measurement range of the proposed system.Finally,experiments and accuracy analyses are performed in situ on an assembled tailplane panel(approximately 1760 mm×460 mm).The automated scanning process is completed in a timeframe of 208s with an average error of less than 0.121 mm for profile reconstruction.Therefore,the proposed method is promising considering both the high accuracy and high efficiency requirements of profile inspections for large aircraft.展开更多
In wind tunnels, long cantilever sting support systems with low structural damping encounter flow separation and turbulence during wind tunnel tests, which results in destructive low-frequency and big-amplitude resona...In wind tunnels, long cantilever sting support systems with low structural damping encounter flow separation and turbulence during wind tunnel tests, which results in destructive low-frequency and big-amplitude resonance, leading to data quality degradation and test envelope limitation. To ensure planed test envelope and obtain high-quality data, an active damping vibration control system independent of balance signal based on stackable piezoelectric actuators and velocity feedback using accelerometer, is proposed to improve the support stability and wind tunnel testing safety in transonic wind tunnel. Meanwhile, a design of powerful sting-root embedded active damping device is given and an active vibration control method is presented based on the mechanism analysis of aircraft model vibration. Furthermore, a self-adaptive fuzzy Proportion Differentiation(PD) control model is proposed to realize control parameters adjustment automatically for various testing conditions. Besides, verification tests are performed in laboratory and a continuous transonic wind tunnel. Experimental results indicate that the aircraft model does not vibrate obviously from -4° to 11° at Ma = 0.6, the number of useable angle-of-attack has increased by 7° at Ma = 0.6 and 5° at Ma = 0.7 respectively, satisfying the requirements of practical wind tunnel tests.展开更多
In wind tunnel tests for the full-model fixed with sting,the low structural damping of the long cantilever sting results in destructive low-frequency and large-amplitude vibration.In order to obtain high-quality wind ...In wind tunnel tests for the full-model fixed with sting,the low structural damping of the long cantilever sting results in destructive low-frequency and large-amplitude vibration.In order to obtain high-quality wind tunnel test data and ensure the safety of wind tunnel tests,an energy-fuzzy adaptive PD(Proportion Differentiation)control method is proposed.This method is used for active vibration control of a cantilever structure under variable aerodynamic load excitation,and real-time adjustment of parameters is achieved according to the system characteristics of vibration energy.Meanwhile,a real-time method is proposed to estimate the real-time vibration energy through the vibration acceleration signal,and the average exciting power of aerodynamic load is obtained by deducting the part of the power contributed by the vibration suppressor from the total power.Furthermore,an energy-fuzzy adaptive PD controller is proposed to achieve adaptive control to the changes of the aerodynamic load.Besides,the subsonic and transonic experiments were carried out in wind tunnel,the results revealed that comparing to fixed gain PD controllers,the energy-fuzzy adaptive PD controller maintains higher performance.展开更多
基金supported in part by project of National Key R&D Program of China(2018YFA0703304)National Natural Science Foundation of China(U1808217)+1 种基金Youth Program of National Natural Science Foundation of China(51905077)Liaoning Revitalization Talents Program(XLYC1807086)。
文摘Three-dimensional(3D)profile scanning plays a crucial role in the inspection of assembled large aircraft.In this paper,to achieve noncontact automatic measurements of the high-reflective profiles of large-scale curved parts and components,an automated noncontact system and method with high accuracy and high efficiency are presented.First,a hybrid 3D coordinate measurement system based on proximity sensors and cameras is proposed to obtain noncontact measurements while avoiding the influence of high reflection on the measurement accuracy.A hybrid measurement model that combines the one-dimensional distances measured by the proximity sensors and the 3D information obtained by cameras is proposed to determine high-accuracy 3D coordinates of the measured points.Then,a profile-driven 3D automated scanning method and strategy are designed to rapidly scan and reconstruct the profile within the effective range without scratching the profile or exceeding the measurement range of the proposed system.Finally,experiments and accuracy analyses are performed in situ on an assembled tailplane panel(approximately 1760 mm×460 mm).The automated scanning process is completed in a timeframe of 208s with an average error of less than 0.121 mm for profile reconstruction.Therefore,the proposed method is promising considering both the high accuracy and high efficiency requirements of profile inspections for large aircraft.
基金co-supported by the National Natural Science Foundation of China (Nos. 51622501 and 51621064)the high-level personnel innovation support program of Dalian (No. 2017RJ04)
文摘In wind tunnels, long cantilever sting support systems with low structural damping encounter flow separation and turbulence during wind tunnel tests, which results in destructive low-frequency and big-amplitude resonance, leading to data quality degradation and test envelope limitation. To ensure planed test envelope and obtain high-quality data, an active damping vibration control system independent of balance signal based on stackable piezoelectric actuators and velocity feedback using accelerometer, is proposed to improve the support stability and wind tunnel testing safety in transonic wind tunnel. Meanwhile, a design of powerful sting-root embedded active damping device is given and an active vibration control method is presented based on the mechanism analysis of aircraft model vibration. Furthermore, a self-adaptive fuzzy Proportion Differentiation(PD) control model is proposed to realize control parameters adjustment automatically for various testing conditions. Besides, verification tests are performed in laboratory and a continuous transonic wind tunnel. Experimental results indicate that the aircraft model does not vibrate obviously from -4° to 11° at Ma = 0.6, the number of useable angle-of-attack has increased by 7° at Ma = 0.6 and 5° at Ma = 0.7 respectively, satisfying the requirements of practical wind tunnel tests.
基金co-supported by the project of National Key R&D Program of China(No.2018YFA0703304)the National Natural Science Foundation of China(No.U1808217)Liaoning Revitalization Talents Program of China(No.XLYC1807086)。
文摘In wind tunnel tests for the full-model fixed with sting,the low structural damping of the long cantilever sting results in destructive low-frequency and large-amplitude vibration.In order to obtain high-quality wind tunnel test data and ensure the safety of wind tunnel tests,an energy-fuzzy adaptive PD(Proportion Differentiation)control method is proposed.This method is used for active vibration control of a cantilever structure under variable aerodynamic load excitation,and real-time adjustment of parameters is achieved according to the system characteristics of vibration energy.Meanwhile,a real-time method is proposed to estimate the real-time vibration energy through the vibration acceleration signal,and the average exciting power of aerodynamic load is obtained by deducting the part of the power contributed by the vibration suppressor from the total power.Furthermore,an energy-fuzzy adaptive PD controller is proposed to achieve adaptive control to the changes of the aerodynamic load.Besides,the subsonic and transonic experiments were carried out in wind tunnel,the results revealed that comparing to fixed gain PD controllers,the energy-fuzzy adaptive PD controller maintains higher performance.