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Dr. Woei Leong Chan
National University of Singapore

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0 flapping wing
0 Wind Load
0 Fractal Tree
0 Micro-Air-Vehicle
0 Unmanned Air Vehicle

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Micro-Air-Vehicle
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Wind Load

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Journal article
Published: 25 July 2020 in Forests
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Estimation of the aerodynamic load on trees is essential for urban tree management to mitigate the risk of tree failure. To assess that in a cost-effective way, scaled down tree models and numerical simulations were utilized. Scaled down tree models reduce the cost of experimental studies and allow the studies to be conducted in a controlled environment, namely in a wind or water tunnel, but the major challenge is to construct a tree model that resembles the real tree. We constructed 3D-printed scaled down fractal tree models of major urban tree species in Singapore using procedural modelling, based on species-specific growth processes and field statistical data gathered through laser scanning of real trees. The tree crowns were modelled to match the optical porosity of real trees. We developed a methodology to model the tree crowns using porous volumes filled with randomized tetrahedral elements. The wind loads acting on the tree models were then measured in the wind tunnel and the velocity profiles from selected models were captured using particle image velocimetry (PIV). The data was then used for the validation of Large Eddy Simulations (LES), in which the trees were modelled via a discretized momentum sink with 10–20 elements in width, height, and depth, respectively. It is observed that the velocity profiles and drag of the simulations and the wind tunnel tests are in reasonable agreement. We hence established a clear relationship between the measured bulk drag on the tree models in the wind tunnel, and the local drag coefficients of the discretized elements in the simulations. Analysis on the bulk drag coefficient also shows that the effect of complex crown shape could be more dominant compared to the frontal optical porosity.

ACS Style

Woei-Leong Chan; Yong Eng; Zhengwei Ge; Chi Wan Calvin Lim; Like Gobeawan; Hee Joo Poh; Daniel Joseph Wise; Daniel C. Burcham; Daryl Lee; Yongdong Cui; Boo Cheong Khoo. Wind Loading on Scaled Down Fractal Tree Models of Major Urban Tree Species in Singapore. Forests 2020, 11, 803 .

AMA Style

Woei-Leong Chan, Yong Eng, Zhengwei Ge, Chi Wan Calvin Lim, Like Gobeawan, Hee Joo Poh, Daniel Joseph Wise, Daniel C. Burcham, Daryl Lee, Yongdong Cui, Boo Cheong Khoo. Wind Loading on Scaled Down Fractal Tree Models of Major Urban Tree Species in Singapore. Forests. 2020; 11 (8):803.

Chicago/Turabian Style

Woei-Leong Chan; Yong Eng; Zhengwei Ge; Chi Wan Calvin Lim; Like Gobeawan; Hee Joo Poh; Daniel Joseph Wise; Daniel C. Burcham; Daryl Lee; Yongdong Cui; Boo Cheong Khoo. 2020. "Wind Loading on Scaled Down Fractal Tree Models of Major Urban Tree Species in Singapore." Forests 11, no. 8: 803.

Research article
Published: 22 July 2020 in Science Robotics
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The aerobatic maneuvers of swifts could be very useful for micro aerial vehicle missions. Rapid arrests and turns would allow flight in cluttered and unstructured spaces. However, these decelerating aerobatic maneuvers have been difficult to demonstrate in flapping wing craft to date because of limited thrust and control authority. Here, we report a 26-gram X-wing ornithopter of 200-millimeter fuselage length capable of multimodal flight. Using tail elevation and high thrust, the ornithopter was piloted to hover, fly fast forward (dart), turn aerobatically, and dive with smooth transitions. The aerobatic turn was achieved within a 32-millimeter radius by stopping a dart with a maximum deceleration of 31.4 meters per second squared. In this soaring maneuver, braking was possible by rapid body pitch and dynamic stall of wings at relatively high air speed. This ornithopter can recover to glide stability without tumbling after a 90-degree body flip. We showed that the tail presented a strong stabilizing moment under high thrust, whereas the wing membrane flexibility alleviated the destabilizing effect of the forewings. To achieve these demands for high thrust, we developed a low-loss anti-whirl transmission that maximized thrust output by the flapping wings to 40 grams in excess of body weight. By reducing the reactive load and whirl, this indirect drive consumed 40% less maximum electrical power for the same thrust generation than direct drive of a propeller. The triple roles of flapping wings for propulsion, lift, and drag enable the performance of aggressive flight by simple tail control.

ACS Style

Yao-Wei Chin; Jia Ming Kok; Yong-Qiang Zhu; Woei-Leong Chan; Javaan S. Chahl; Boo Cheong Khoo; Gih-Keong Lau. Efficient flapping wing drone arrests high-speed flight using post-stall soaring. Science Robotics 2020, 5, eaba2386 .

AMA Style

Yao-Wei Chin, Jia Ming Kok, Yong-Qiang Zhu, Woei-Leong Chan, Javaan S. Chahl, Boo Cheong Khoo, Gih-Keong Lau. Efficient flapping wing drone arrests high-speed flight using post-stall soaring. Science Robotics. 2020; 5 (44):eaba2386.

Chicago/Turabian Style

Yao-Wei Chin; Jia Ming Kok; Yong-Qiang Zhu; Woei-Leong Chan; Javaan S. Chahl; Boo Cheong Khoo; Gih-Keong Lau. 2020. "Efficient flapping wing drone arrests high-speed flight using post-stall soaring." Science Robotics 5, no. 44: eaba2386.

Journal article
Published: 01 July 2020 in AIP Advances
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In this work, we adopt the integration of the L-system fractal tree generation, 3D printed wind tunnel modeling, and computational fluid dynamics (CFD) simulation approach to model the wind effect on a single tree. We compare the agreement between CFD simulations and wind tunnel measurements of rigid branched structures resembling trees. First, fractal tree mesh models based on species growth and branching patterns are developed to represent tree species for wind–tree modeling. Subsequently, a scaled-down fractal tree is generated with 3D-printing and subjected to tunnel testing with load cell and particle image velocimetry measurement data under the wind speed of 10 m/s and 15 m/s. Finally, CFD based on Reynolds-Average Navier–Stokes (RANS) simulation with a full closure model and Large Eddy Simulation (LES) using appropriate momentum sink and turbulence source terms for the volumetric tree is carried out. We use both the volume-average porous media and the volume-splitting discretized zones (split number 10 × 10 × 10) to reproduce the momentum sink effect in the numerical simulation. Three tree species, namely, Peltophorum pterocarpum (yellow flame), Khaya senegalensis (African mahogany), and Hopea odorata (ironwood), are tested, and a reasonable agreement of drag force prediction and velocity profiles is obtained when comparing the CFD simulation results with wind tunnel data. The RANS modeled drag force results exhibit 20% of over-prediction, while the normalized velocity profiles display a good match of velocity decay at the tree leeward sides. On the other hand, LES produces much better results with only 3% discrepancy with the experimental results. A comparison of experimental results among the tree species is also carried out. Due to the actual random wind direction, tree slenderness representation, and structural flexibility issues, the current methodology still has the limitation for validation with urban on-site measurement. Nonetheless, this integrated approach is the first step in establishing modeling tool applicability to examine the effect of the forest structure and composition on wind loads.

ACS Style

Hee Joo Poh; Woei Leong Chan; Daniel J. Wise; Chi Wan Lim; Boo Cheong Khoo; Like Gobeawan; Zhengwei Ge; Yong Eng; Jia Xin Peng; Venugopalan S. G. Raghavan; Siddharth Sunil Jadhav; Jing Lou; Y. D. Cui; Heow Pueh Lee; Daniel Christopher Burcham; Daryl Lee; Kelvin Wenhui Li; Irene Lee. Wind load prediction on single tree with integrated approach of L-system fractal model, wind tunnel, and tree aerodynamic simulation. AIP Advances 2020, 10, 075202 .

AMA Style

Hee Joo Poh, Woei Leong Chan, Daniel J. Wise, Chi Wan Lim, Boo Cheong Khoo, Like Gobeawan, Zhengwei Ge, Yong Eng, Jia Xin Peng, Venugopalan S. G. Raghavan, Siddharth Sunil Jadhav, Jing Lou, Y. D. Cui, Heow Pueh Lee, Daniel Christopher Burcham, Daryl Lee, Kelvin Wenhui Li, Irene Lee. Wind load prediction on single tree with integrated approach of L-system fractal model, wind tunnel, and tree aerodynamic simulation. AIP Advances. 2020; 10 (7):075202.

Chicago/Turabian Style

Hee Joo Poh; Woei Leong Chan; Daniel J. Wise; Chi Wan Lim; Boo Cheong Khoo; Like Gobeawan; Zhengwei Ge; Yong Eng; Jia Xin Peng; Venugopalan S. G. Raghavan; Siddharth Sunil Jadhav; Jing Lou; Y. D. Cui; Heow Pueh Lee; Daniel Christopher Burcham; Daryl Lee; Kelvin Wenhui Li; Irene Lee. 2020. "Wind load prediction on single tree with integrated approach of L-system fractal model, wind tunnel, and tree aerodynamic simulation." AIP Advances 10, no. 7: 075202.

Journal article
Published: 01 December 2018 in AIAA Journal
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This work investigates the acoustic and thrust performances of different wing designs for a two-winged flapping-wing micro air vehicle (FW-MAV). The reference wings, made of a Mylar film membrane supported by carbon-fiber rods, produce a perceived overall noise of about 68.8 dBA when operating at the flapping frequency of 10 Hz typically required for flying such a flapping wing vehicle. This noise is much higher than the value of the environmental background. Wings of various materials and structural configurations are designed and tested in order to reduce the flapping-wing noise. Sound and force measurements are used to assess their acoustic and lift capabilities. It is found that a wing made with a highly elastic dielectric elastomer membrane can reduce the overall perceived noise of the flapping wing by 12 dBA while slightly increasing the thrust. The mechanisms leading to this noise reduction and their potential applications in quiet FW-MAVs are discussed.

ACS Style

Zhenbo Lu; Marco DeBiasi; Quoc-Viet Nguyen; Woei-Leong Chan. Bioinspired Low-Noise Wing Design for a Two-Winged Flapping-Wing Micro Air Vehicle. AIAA Journal 2018, 56, 4697 -4705.

AMA Style

Zhenbo Lu, Marco DeBiasi, Quoc-Viet Nguyen, Woei-Leong Chan. Bioinspired Low-Noise Wing Design for a Two-Winged Flapping-Wing Micro Air Vehicle. AIAA Journal. 2018; 56 (12):4697-4705.

Chicago/Turabian Style

Zhenbo Lu; Marco DeBiasi; Quoc-Viet Nguyen; Woei-Leong Chan. 2018. "Bioinspired Low-Noise Wing Design for a Two-Winged Flapping-Wing Micro Air Vehicle." AIAA Journal 56, no. 12: 4697-4705.

Accepted manuscript
Published: 09 November 2018 in Bioinspiration & Biomimetics
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Tailless Flapping Wing Micro Air Vehicle (FW-MAV) is one of the most challenging problems in flapping wing design due to its lack of tail for inherent flight stability. It must be designed in such a way that it can produce proper augmented control moments modulated by a closed-loop attitude controller for active stabilization. We propose a tailless FW-MAV with wing stroke plane modulation mechanism, namely NUS-Roboticbird, which manoeuvres by only using its flapping wings for both propulsion and attitude control. The flying vehicle has four wings comprised by two pairs, each pair of wings and its stroke plane are driven by a motor and a servo, respectively. Attitude control moments of roll, pitch, and yaw are generated by vectoring a pair of thrusts, which are resulted from changing the flapping frequency (or motor speed) and wing stroke plane of the two pairs of wings. Free flight tests show that the vehicle can climb and descend vertically (throttle control), fly sideways left and right (roll-control), fly forward and backward (pitch-control), rotate clockwise and counter-clockwise (yaw-control), hover in mid-air (active self-stabilization), and maneuver in the figure-of-8 and fast forward/backward flight. These abilities are especially important for surveillance and autonomous flight in terms of obstacle avoidance in indoor environment. Flight test data shows that effective mechanical control mechanism and control gains for attitude-controlled flights for roll, pitch, and yaw are achieved, in particularly, yaw-control. Currently, the vehicle weighing 31g and having a wing span of 22cm can perform fast forward flight at speed of about 5m/s (18km/h) and endure 3.5 minutes in flight with a useful payload of 4.5g onboard camera for surveillance.

ACS Style

Quoc-Viet Nguyen; Woei Leong Chan. Development and flight performance of a biologically-inspired tailless flapping-wing micro air vehicle with wing stroke plane modulation. Bioinspiration & Biomimetics 2018, 14, 016015 .

AMA Style

Quoc-Viet Nguyen, Woei Leong Chan. Development and flight performance of a biologically-inspired tailless flapping-wing micro air vehicle with wing stroke plane modulation. Bioinspiration & Biomimetics. 2018; 14 (1):016015.

Chicago/Turabian Style

Quoc-Viet Nguyen; Woei Leong Chan. 2018. "Development and flight performance of a biologically-inspired tailless flapping-wing micro air vehicle with wing stroke plane modulation." Bioinspiration & Biomimetics 14, no. 1: 016015.

Journal article
Published: 02 October 2017 in Journal of Alloys and Compounds
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Electrodeposition of a thin ferromagnetic film with excellent magnetic dynamic properties at gigahertz range is challenging due to the easy oxidation of the active metals. Hence developing a feasible method to decrease the oxidation upon understanding the oxidation mechanism during the electrodeposition is critical. Here we report a simple methodology to successfully electrodeposit thin magnetic soft FeCo films with large complex permeability and high resonant frequency by means of inert gas-purging in the plating solution. The study of mechanism on the electrodeposition of active FeCo films depicts that the purging of inert N2 largely reduces the oxygen content in the plating solution, which subsequently suppresses the oxidation of iron ions, increases the Fe-atom ratio, and also perturbs the crystal growth of the as-deposited FeCo film. This in turn leads to the thin film with significantly reduced oxygen content, smaller grain size, and lower crystallinity, hence increased magnetic moment, decreased coercivity, and notably improved complex permeability of thin FeCo film. Typically, the films have a coercivity as low as 8 Oe, large saturation flux density up to 2.38 T, and ultra-high permeability up to ∼1200 (real part). As such, these thin films have the advantage in the applications for high frequency gigahertz devices.

ACS Style

B.Y. Zong; Y.P. Wu; Pin Ho; W.L. Chan; Y. Yang; C. Zhao; T.W. Deng; N.N. Phuoc; Z.W. Li. N 2 purging effect on electrodeposition of active ferromagnetic thin FeCo films. Journal of Alloys and Compounds 2017, 730, 284 -290.

AMA Style

B.Y. Zong, Y.P. Wu, Pin Ho, W.L. Chan, Y. Yang, C. Zhao, T.W. Deng, N.N. Phuoc, Z.W. Li. N 2 purging effect on electrodeposition of active ferromagnetic thin FeCo films. Journal of Alloys and Compounds. 2017; 730 ():284-290.

Chicago/Turabian Style

B.Y. Zong; Y.P. Wu; Pin Ho; W.L. Chan; Y. Yang; C. Zhao; T.W. Deng; N.N. Phuoc; Z.W. Li. 2017. "N 2 purging effect on electrodeposition of active ferromagnetic thin FeCo films." Journal of Alloys and Compounds 730, no. : 284-290.

Research article
Published: 28 March 2017 in International Journal of Micro Air Vehicles
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Experimental investigation of wing flexibility on vertical thrust generation and power consumption in hovering condition for a hovering Flapping-Wing Micro Air Vehicle, namely FlowerFly, weighing 14.5 g with a 3 g onboard battery and having four wings with double wing clap-and-fling effects, was conducted for several wing configurations with the same shape, area, and weight. A data acquisition system was set up to simultaneously record aerodynamic forces, electrical power consumption, and wing motions at various flapping frequencies. The forces and power consumption were measured with a loadcell and a custom-made shunt circuit, respectively, and the wing motion was captured by high-speed cameras. The results show a phase delay of the wing tip displacement observed for wings with high flexible leading edge at high frequency, resulting in less vertical thrust produced when compared with the wings with less leading edge flexibility at the same flapping frequency. Positive wing camber was observed during wing flapping motion by arranging the wing supporting ribs. Comparison of thrust-to-power ratios between the wing configurations was undertaken to figure out a wing configuration for high vertical thrust production but less power consumption.

ACS Style

Quoc V Nguyen; Woei L Chan; Marco DeBiasi. Experimental investigation of wing flexibility on force generation of a hovering flapping wing micro air vehicle with double wing clap-and-fling effects. International Journal of Micro Air Vehicles 2017, 9, 187 -197.

AMA Style

Quoc V Nguyen, Woei L Chan, Marco DeBiasi. Experimental investigation of wing flexibility on force generation of a hovering flapping wing micro air vehicle with double wing clap-and-fling effects. International Journal of Micro Air Vehicles. 2017; 9 (3):187-197.

Chicago/Turabian Style

Quoc V Nguyen; Woei L Chan; Marco DeBiasi. 2017. "Experimental investigation of wing flexibility on force generation of a hovering flapping wing micro air vehicle with double wing clap-and-fling effects." International Journal of Micro Air Vehicles 9, no. 3: 187-197.

Journal article
Published: 01 June 2016 in Journal of Bionic Engineering
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Hovering ability is one of the most desired features in Flapping-Wing Micro Air Vehicles (FW-MAVs). This paper presents a hybrid design of flapping wing and fixed wing, which combines two flapping wings and two fixed wings to take advantage of the double wing clap-and-fling effect for high thrust production, and utilizes the fixed wings as the stabilizing surfaces for inherently stable hovering flight. Force measurement shows that the effect of wing clap-and-fling significantly enhances the cycle-averaged vertical thrust up to 44.82% at 12.4 Hz. The effect of ventral wing clap-and-fling due to presence of fixed wings produces about 11% increase of thrust-to-power ratio, and the insect-inspired FW-MAV can produce enough cycle-averaged vertical thrust of 14.76 g for lift-off at 10 Hz, and 24 g at maximum frequency of 12.4 Hz. Power measurement indicates that the power consumed for aerodynamic forces and wing inertia, and power loss due to gearbox friction and mechanism inertia was about 80% and 20% of the total input power, respectively. The proposed insect-inspired FW-MAV could endure three-minute flight, and demonstrate a good flight performance in terms of vertical take-off, hovering, and control with an onboard 3.7 V-70 mAh LiPo battery and control system.

ACS Style

Quoc-Viet Nguyen; Woei Leong Chan; Marco Debiasi. Hybrid design and performance tests of a hovering insect-inspired flapping-wing micro aerial vehicle. Journal of Bionic Engineering 2016, 13, 235 -248.

AMA Style

Quoc-Viet Nguyen, Woei Leong Chan, Marco Debiasi. Hybrid design and performance tests of a hovering insect-inspired flapping-wing micro aerial vehicle. Journal of Bionic Engineering. 2016; 13 (2):235-248.

Chicago/Turabian Style

Quoc-Viet Nguyen; Woei Leong Chan; Marco Debiasi. 2016. "Hybrid design and performance tests of a hovering insect-inspired flapping-wing micro aerial vehicle." Journal of Bionic Engineering 13, no. 2: 235-248.

Journal article
Published: 08 January 2016 in The Journal of Instrumentation, Automation and Systems
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A preliminary study on the stability of a bi-flap flapping wing hovering platform is presented in this paper. The work includes the derivation of cycle-average linear longitudinal and lateral models, the experiment to determine the stability derivatives, and analysis on the identified system matrices. Also discussed in the paper is the validity of using a cycle-averaged model to represent the dynamics of the flapping wing platform, and the validity of using small perturbation theory to linearize the nonlinear model. Results show that the platform is unstable longitudinally and laterally about the hovering equilibrium. Longitudinally, the natural modes are short period unstable oscillatory mode, fast subsidence mode, and slow divergent mode. Laterally, the natural modes are neutral mode, fast subsidence mode, and long period unstable oscillatory mode.

ACS Style

Woei Leong Chan; Muhammad Azli Bin Jaffar; Quoc Viet Nguyen. Preliminary Study on Stability of a Hovering Bi-flap Flapping Wing Platform using Cycle-Averaged Linear Models. The Journal of Instrumentation, Automation and Systems 2016, 1, 84 -90.

AMA Style

Woei Leong Chan, Muhammad Azli Bin Jaffar, Quoc Viet Nguyen. Preliminary Study on Stability of a Hovering Bi-flap Flapping Wing Platform using Cycle-Averaged Linear Models. The Journal of Instrumentation, Automation and Systems. 2016; 1 (3):84-90.

Chicago/Turabian Style

Woei Leong Chan; Muhammad Azli Bin Jaffar; Quoc Viet Nguyen. 2016. "Preliminary Study on Stability of a Hovering Bi-flap Flapping Wing Platform using Cycle-Averaged Linear Models." The Journal of Instrumentation, Automation and Systems 1, no. 3: 84-90.

Conference paper
Published: 02 January 2016 in 54th AIAA Aerospace Sciences Meeting
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ACS Style

Marco Debiasi; Woei Leong Chan; Siddharth Jadhav. Measurements of a Symmetric Wing Morphed by Macro Fiber Composite Actuators. 54th AIAA Aerospace Sciences Meeting 2016, 1 .

AMA Style

Marco Debiasi, Woei Leong Chan, Siddharth Jadhav. Measurements of a Symmetric Wing Morphed by Macro Fiber Composite Actuators. 54th AIAA Aerospace Sciences Meeting. 2016; ():1.

Chicago/Turabian Style

Marco Debiasi; Woei Leong Chan; Siddharth Jadhav. 2016. "Measurements of a Symmetric Wing Morphed by Macro Fiber Composite Actuators." 54th AIAA Aerospace Sciences Meeting , no. : 1.

Journal article
Published: 13 May 2015 in Aerospace
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In this paper, an ornithopter prototype that mimics the flapping motion of bird flight is developed, and the lift and thrust generation characteristics of different wing designs are evaluated. This project focused on the spar arrangement and material used for the wings that could achieves improved performance. Various lift and thrust measurement techniques are explored and evaluated. Various wings of insects and birds were evaluated to understand how these natural flyers with flapping wings are able to produce sufficient lift to fly. The differences in the flapping aerodynamics were also detailed. Experiments on different wing designs and materials were conducted and a paramount wing was built for a test flight. The first prototype has a length of 46.5 cm, wing span of 88 cm, and weighs 161 g. A mechanism which produced a flapping motion was fabricated and designed to create flapping flight. The flapping flight was produced by using a single motor and a flexible and light wing structure. A force balance made of load cell was then designed to measure the thrust and lift force of the ornithopter. Three sets of wings varying flexibility were fabricated, therefore lift and thrust measurements were acquired from each different set of wings. The lift will be measured in ten cycles computing the average lift and frequency in three different speeds or frequencies (slow, medium and fast). The thrust measurement was measure likewise but in two cycles only. Several observations were made regarding the behavior of flexible flapping wings that should aid in the design of future flexible flapping wing vehicles. The wings angle or phase characteristic were analyze too and studied. The final ornithopter prototype weighs only 160 g, has a wing span of 88.5 cm, that could flap at a maximum flapping frequency of 3.869 Hz, and produce a maximum thrust and lift of about 0.719 and 0.264 N respectively. Next, we proposed resonance type flapping wing utilizes the near resonance phenomenon of a two-degree of freedom elastic system, that is, the wing is supported by the springs for flapping and feathering motions. Being oscillated close to the resonance frequency of the system, only by the torque in flapping motion, the amplitude gained is a few times higher than that of normal case. The first prototype was made from acrylic using a laser cutting machine. The wings were made up of carbon rods and kite material Ripstop. First test showed that the wings were too heavy for the mechanism to work. The third prototype was a smaller single gear crank design which was fabricated using a 3D printer. Initial test proved that the second prototype could withstand the high frequency flapping and near resonance amplitude as designed. With remote control, the third prototype was able to take off, climb, cruise and land in flapping mode successfully.

ACS Style

Sutthiphong Srigrarom; Woei-Leong Chan. Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles. Aerospace 2015, 2, 235 -278.

AMA Style

Sutthiphong Srigrarom, Woei-Leong Chan. Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles. Aerospace. 2015; 2 (2):235-278.

Chicago/Turabian Style

Sutthiphong Srigrarom; Woei-Leong Chan. 2015. "Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles." Aerospace 2, no. 2: 235-278.

Conference paper
Published: 26 March 2015 in Bioinspiration, Biomimetics, and Bioreplication 2015
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ACS Style

Quoc-Viet Nguyen; Woei Leong Chan; Marco DeBiasi. An insect-inspired flapping wing micro air vehicle with double wing clap-fling effects and capability of sustained hovering. Bioinspiration, Biomimetics, and Bioreplication 2015 2015, 94290U -94290U-11.

AMA Style

Quoc-Viet Nguyen, Woei Leong Chan, Marco DeBiasi. An insect-inspired flapping wing micro air vehicle with double wing clap-fling effects and capability of sustained hovering. Bioinspiration, Biomimetics, and Bioreplication 2015. 2015; ():94290U-94290U-11.

Chicago/Turabian Style

Quoc-Viet Nguyen; Woei Leong Chan; Marco DeBiasi. 2015. "An insect-inspired flapping wing micro air vehicle with double wing clap-fling effects and capability of sustained hovering." Bioinspiration, Biomimetics, and Bioreplication 2015 , no. : 94290U-94290U-11.

Conference paper
Published: 13 June 2014 in 32nd AIAA Applied Aerodynamics Conference
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ACS Style

Yann Bouremel; Woei Leong Chan; Gareth Jones; Marco Debiasi. Measurements of a Symmetric Airfoil Morphed by Macro Fiber Composite Actuators. 32nd AIAA Applied Aerodynamics Conference 2014, 1 .

AMA Style

Yann Bouremel, Woei Leong Chan, Gareth Jones, Marco Debiasi. Measurements of a Symmetric Airfoil Morphed by Macro Fiber Composite Actuators. 32nd AIAA Applied Aerodynamics Conference. 2014; ():1.

Chicago/Turabian Style

Yann Bouremel; Woei Leong Chan; Gareth Jones; Marco Debiasi. 2014. "Measurements of a Symmetric Airfoil Morphed by Macro Fiber Composite Actuators." 32nd AIAA Applied Aerodynamics Conference , no. : 1.

Journal article
Published: 19 August 2011 in Measurement Science and Technology
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ACS Style

Woei Leong Chan; C S Lee; F B Hsiao. Real-time approaches to the estimation of local wind velocity for a fixed-wing unmanned air vehicle. Measurement Science and Technology 2011, 22, 1 .

AMA Style

Woei Leong Chan, C S Lee, F B Hsiao. Real-time approaches to the estimation of local wind velocity for a fixed-wing unmanned air vehicle. Measurement Science and Technology. 2011; 22 (10):1.

Chicago/Turabian Style

Woei Leong Chan; C S Lee; F B Hsiao. 2011. "Real-time approaches to the estimation of local wind velocity for a fixed-wing unmanned air vehicle." Measurement Science and Technology 22, no. 10: 1.

Journal article
Published: 28 March 2011 in Sensors
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This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV). The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA) and angle of sideslip (AoS) measurement, and an Attitude and Heading Reference System (AHRS) that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS) smoother, which consists of a forward pass Extended Kalman Filter (EKF) and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS). It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD) is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly.

ACS Style

Woei-Leong Chan; Fei-Bin Hsiao. Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle. Sensors 2011, 11, 3738 -3764.

AMA Style

Woei-Leong Chan, Fei-Bin Hsiao. Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle. Sensors. 2011; 11 (4):3738-3764.

Chicago/Turabian Style

Woei-Leong Chan; Fei-Bin Hsiao. 2011. "Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle." Sensors 11, no. 4: 3738-3764.

Journal article
Published: 27 January 2011 in The Aeronautical Journal
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This paper presents the design and implementation of automatic flight controllers for a fixed-wing unmanned air vehicle (UAV) by using a linear-quadratic-Gaussian (LQG) control approach. The LQG design is able to retain the guaranteed closed-loop stability of the linear-quadratic regulator (LQR) while having incomplete state measurement. Instead of feeding back the actual states to form the control law, the estimated states provided by a separately designed optimal observer, i.e. the Kalman filter are used. The automatic flight controllers that include outer-loop controls are constructed based on two independent LQG regulators which govern the longitudinal and lateral dynamics of the UAV respectively. The resulting controllers are structurally simple and thus efficient enough to be easily realized with limited onboard computing resource. In this paper, the design of the LQG controllers is described while the navigation and guidance algorithm based on Global Positioning System (GPS) data is also outlined. In order to validate the performance of the automatic flight control system, a series of flight tests have been conducted. Significant results are presented and discussed in detail. Overall, the flight-test results show that it is highly feasible and effective to apply the computationally efficient LQG controllers on a fixed-wing UAV system with a relatively simple onboard system. On the other hand, a fully automatic 44km cross-sea flight demonstration was successfully conducted using the LQG-based flight controllers. Detailed description regarding the event and some significant flight data are given.

ACS Style

C.-S. Lee; W.-L. Chan; S.-S. Jan; F.-B. Hsiao. A linear-quadratic-Gaussian approach for automatic flight control of fixed-wing unmanned air vehicles. The Aeronautical Journal 2011, 115, 29 -41.

AMA Style

C.-S. Lee, W.-L. Chan, S.-S. Jan, F.-B. Hsiao. A linear-quadratic-Gaussian approach for automatic flight control of fixed-wing unmanned air vehicles. The Aeronautical Journal. 2011; 115 (1163):29-41.

Chicago/Turabian Style

C.-S. Lee; W.-L. Chan; S.-S. Jan; F.-B. Hsiao. 2011. "A linear-quadratic-Gaussian approach for automatic flight control of fixed-wing unmanned air vehicles." The Aeronautical Journal 115, no. 1163: 29-41.

Journal article
Published: 01 March 2008 in Journal of Aircraft
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ACS Style

Fei-Bin Hsiao; Sheng-Yen Hsieh; Woei Leong Chan; Ying-Chih Lai. Engine Speed and Velocity Controller Development for Small Unmanned Aerial Vehicle. Journal of Aircraft 2008, 45, 725 -728.

AMA Style

Fei-Bin Hsiao, Sheng-Yen Hsieh, Woei Leong Chan, Ying-Chih Lai. Engine Speed and Velocity Controller Development for Small Unmanned Aerial Vehicle. Journal of Aircraft. 2008; 45 (2):725-728.

Chicago/Turabian Style

Fei-Bin Hsiao; Sheng-Yen Hsieh; Woei Leong Chan; Ying-Chih Lai. 2008. "Engine Speed and Velocity Controller Development for Small Unmanned Aerial Vehicle." Journal of Aircraft 45, no. 2: 725-728.

Conference paper
Published: 08 January 2007 in 45th AIAA Aerospace Sciences Meeting and Exhibit
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Fei-Bin Hsiao; Woei Leong Chan; Ying-Chih Lai; Li-Che Tseng; Sheng-Yen Hsieh; Hian-Kun Tenn. Landing Longitudinal Control System Design for a Fixed Wing UAV. 45th AIAA Aerospace Sciences Meeting and Exhibit 2007, 1 .

AMA Style

Fei-Bin Hsiao, Woei Leong Chan, Ying-Chih Lai, Li-Che Tseng, Sheng-Yen Hsieh, Hian-Kun Tenn. Landing Longitudinal Control System Design for a Fixed Wing UAV. 45th AIAA Aerospace Sciences Meeting and Exhibit. 2007; ():1.

Chicago/Turabian Style

Fei-Bin Hsiao; Woei Leong Chan; Ying-Chih Lai; Li-Che Tseng; Sheng-Yen Hsieh; Hian-Kun Tenn. 2007. "Landing Longitudinal Control System Design for a Fixed Wing UAV." 45th AIAA Aerospace Sciences Meeting and Exhibit , no. : 1.