Full-Scale Demonstration of Higher Harmonic Control for Noise and Vibration Reduction on the XV-15 Rotor

Nguyen, Kristy; Betzina, Mark D.; Kitaplioglu, Cahit

doi:10.4050/jahs.46.182

Cited by 38 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, additional mechanical backlash, friction and elasticity are added to the system by the addition of a gearbox having a high reduction ratio. EMA's with high output inertia has necessary low motion control bandwidth and cannot generally perform high frequency operations, such as gust load alleviation for airplanes and higher harmonic control for helicopters (~30 Hz ) [8][9] [10]. In all, the use of EMAs combined with a disconnect element in a system with multiple outputs, such as for aircraft primary flight control, lead to heavy systems with limited dynamic performance.…”

Section: Introductionmentioning

confidence: 99%

Reliable and lightweight primary flight control actuation using magneto-rheological clutches in slippage

Chouinard

Denninger

Plante

2015

2015 IEEE International Conference on Robotics and Automation (ICRA)

View full text Add to dashboard Cite

Replacing aircraft hydraulic actuators with ElectroMechanical Actuators (EMAs) is seen as a necessary step towards the development of safer and more efficient aircraft with minimal environmental impact. EMAs are commonly used in a wide range of applications as they have improved efficiency over hydraulic actuators. However, in their current form, EMAs do not comply with the stringent weight and reliability requirements of primary flight control applications. This paper describes an Active Torque Distribution (ATD) system that could meet flight control reliability requirements, be lightweight, and increase the dynamic performance of current flight controls. The proposed ATD system uses magneto-rheological clutches to modulate the torque transferred from a centralized velocity source to various control surfaces. The fundamental advantage of this approach is found in the fluidic nature of magneto-rheological clutch interfaces which transmit torque without any solid mechanical contact thus preventing wear and failure causing mechanical seizure. The analytical study used to scale an ATD system and an analogue EMA system based on a representative flight control application shows that the proposed ATD system is 42% lighter than a system composed of EMAs and has a weight similar to that of current hydraulic actuators. Furthermore, this study demonstrates that ATD systems add ~100x less inertia to flight surfaces than EMAs allowing implementation of load alleviation control algorithms requiring high frequency motion (~30 Hz). A proof-of-concept clutch and controller confirm the analytical predictions and validate the possibility of using magneto-rheological clutches for flight control actuation.

show abstract

Section: Introductionmentioning

confidence: 99%

Reliable and lightweight primary flight control actuation using magneto-rheological clutches in slippage

Chouinard

Denninger

Plante

2015

2015 IEEE International Conference on Robotics and Automation (ICRA)

View full text Add to dashboard Cite

show abstract

“…Active rotor control has been studied for several years, but most studies were for blade-vortex interaction (BVI) noise. It can be achieved through higher harmonic control [8][9][10], individual blade control [11][12][13], active flaps [14][15][16][17], and active twist [18][19][20]. The numerical and test results demonstrate that the active rotors are effective for BVI noise and vibration reduction as well as performance enhancement.…”

Section: Introductionmentioning

confidence: 99%

Helicopter Rotor Thickness Noise Control Using Unsteady Force Excitation

Shi

et al. 2019

Applied Sciences

View full text Add to dashboard Cite

The low-frequency in-plane thickness noise generating from the displacement of air by rotating blades has an important influence on helicopter detection. An on-blade control technique to reduce thickness noise is developed in this paper based on the principle of sound field cancellation. Following the theoretical study on the mechanism of thickness noise reduction using in-plane unsteady force, a 2-m diameter rotor with an active trailing-edge winglet are designed and tested in a fully anechoic chamber. The winglet installed on the outboard blade is used to generate the unsteady force and anti-noise to counteract the thickness noise. The results demonstrate that effective reduction of thickness noise up to 3 dB is achieved in the front of the rotor when the winglet is under the one-harmonic control with 3 ° of deflection angle. Moreover, the experiments of frequency, amplitude, and phase scanning are carried out to study the parametric effects of winglet motions on noise reduction. The ability of noise reduction is proportional to the deflection amplitude of the winglet in each frequency. The control phase determines where noise can be reduced. There is an optimal phase angle at each frequency to minimize the noise at the observations, and it varies with different frequencies. The relationship among observation position, control phase, and frequency is derived, and the approximate expression of the optimal phase is presented.

show abstract

“…This is very challenging in nature. For example, the Higher Harmonic Control (HHC) [3] method employs hydraulic actuators to drive the swashplate and adjust the pitch angle of the rotating blades dynamically in order to reduce the N/rev harmonic peaks of the aerodynamic load. Another method is the Individual Blade Control (IBC), in which the rotor blades are designed with actively adjustable trailing edge flaps [4] or integral blade tip twist mechanisms [5] to minimize the N/rev aerodynamic loads using smart material actuators.…”

Section: Introductionmentioning

confidence: 99%

Development of adaptive helicopter seat systems for aircrew vibration mitigation

2008

View full text Add to dashboard Cite

Helicopter aircrews are exposed to high levels of whole body vibration during flight. This paper presents the results of an investigation of adaptive seat mount approaches to reduce helicopter aircrew whole body vibration levels. A flight test was conducted on a four-blade helicopter and showed that the currently used passive seat systems were not able to provide satisfactory protection to the helicopter aircrew in both front-back and vertical directions. Long-term exposure to the measured whole body vibration environment may cause occupational health issues such as spine and neck strain injuries for aircrew. In order to address this issue, a novel adaptive seat mount concept was developed to mitigate the vibration levels transmitted to the aircrew body. For proof-of-concept demonstration, a miniature modal shaker was properly aligned between the cabin floor and the seat frame to provide adaptive actuation authority. Adaptive control laws were developed to reduce the vibration transmitted to the aircrew body, especially the helmet location in order to minimize neck and spine injuries. Closed-loop control test have been conducted on a full-scale helicopter seat with a mannequin configuration and a large mechanical shaker was used to provide representative helicopter vibration profiles to the seat frame. Significant vibration reductions to the vertical and front-back vibration modes have been achieved simultaneously, which verified the technical readiness of the adaptive mount approach for full-scale flight test on the vehicle.

show abstract

Full-Scale Demonstration of Higher Harmonic Control for Noise and Vibration Reduction on the XV-15 Rotor

Cited by 38 publications

References 9 publications

Reliable and lightweight primary flight control actuation using magneto-rheological clutches in slippage

Reliable and lightweight primary flight control actuation using magneto-rheological clutches in slippage

Helicopter Rotor Thickness Noise Control Using Unsteady Force Excitation

Development of adaptive helicopter seat systems for aircrew vibration mitigation

Contact Info

Product

Resources

About