Analysis of low-speed height-velocity diagram of a variable-speed-rotor helicopter in one-engine-failure

Chi, Cheng; Yan, Xufei; Chen, Renliang; Pan, Li

doi:10.1016/j.ast.2019.05.003

Cited by 18 publications

(3 citation statements)

References 10 publications

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“…To solve the nonlinear boundary value problem, a collocation method called direct multiple shooting [30,34] is utilised. The problem is then transcribed into discrete nonlinear programming (NLP) by discretizing continuous states and controls into short time segments.…”

Section: Takeoff Path Predictionmentioning

confidence: 99%

Propeller control for takeoff of a heavily loaded coaxial compound helicopter

et al. 2023

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Although a coaxial compound helicopter can takeoff without propeller in the normal condition, the distance should be as short as possible for obstacle avoidance when the vehicle operates in a confined area with heavy loads. Therefore, a suitable propeller control is required to improve the takeoff performance while the total power consumption is no more than the available power. The path is predicted by applying trajectory optimisation. Several varying takeoff parameters, including attitude, liftoff speed and obstacle height, are considered for optimum global performance. Three path indicators are proposed. Apart from typical distance and pilot workload, path sensitivity is quantified based on deviation from takeoff parameter variation. Results indicated that low propeller thrust at hover and moderate allocation on the propeller through flight is recommended. The aircraft achieves significantly improved takeoff performance compared to flight with pure rotors while maintaining the maximum takeoff weight. The distance is shortened by 12.6%, and the longitudinal pilot workload is alleviated by 9.8% and 7.3% from mean and maximum power frequency aspects. Besides, the path is less sensitive to takeoff parameter variations, such as speed, altitude and height.

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Section: Takeoff Path Predictionmentioning

confidence: 99%

Propeller control for takeoff of a heavily loaded coaxial compound helicopter

et al. 2023

Self Cite

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“…This performance specification for autonomy has resulted in high complexity in the rotorcraft flight control system. Significant effort has been devoted to improving the performance and reliability of flight control systems in the past two decades [1], and the increase in computational power and communication bandwidth has made possible some of the improvements that have eluded control engineers in recent years [5].…”

Section: Introductionmentioning

confidence: 99%

Optimised Tuning of a PID-Based Flight Controller for a Medium-Scale Rotorcraft

Mpanza

Pedro

2021

Algorithms

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This paper presents the parameter optimisation of the flight control system of a singlerotor medium-scale rotorcraft. The six degrees-of-freedom (DOF) nonlinear mathematical model of the rotorcraft is developed. This model is then used to develop proportional–integral–derivative (PID)-based controllers. Since the majority of PID controllers installed in industry are poorly tuned, this paper presents a comparison of the optimised tuning of the flight controller parameters using particle swarm optimisation (PSO), genetic algorithm (GA), ant colony optimisation (ACO) and cuckoo search (CS) optimisation algorithms. The aim is to find the best PID parameters that minimise the specified objective function. Two trim conditions are investigated, i.e., hover and 10 m/s forward flight. The four algorithms performed better than manual tuning of the PID controllers. It was found, through numerical simulation, that the ACO algorithm converges the fastest and finds the best gains for the selected objective function in hover trim conditions. However, for 10 m/s forward flight trim, the GA algorithm was found to be the best. Both the tuned flight controllers managed to reject a gust wind of up to 5 m/s in the lateral axis in hover and in forward flight.

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“…For the same helicopter, Chi et. al [15] demonstrated that the VRS technology can improve landing performance in One Engine Inoperative (OEI) conditions. Karem [11] investigated the performance benefits of a VRS tilt-rotor, showing up to 52% and 60% power reductions for hovering and cruising at low-tomoderate weights and altitudes.…”

mentioning

confidence: 99%

On the Effects of Optimal Implementation of Variable Rotor Speed and Power Management on Hybrid-Electric Rotorcraft

Saias

Goulos

Pachidis

et al. 2023

Journal of Engineering for Gas Turbines and Power

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The concept of Variable Rotor Speed (VRS) has been recognized as an efficient means to improve rotorcraft operational performance and environmental impact, with electrification being a potential technology to further contribute to that. This paper explores the impact of optimal implementation and scheduling of VRS and power management strategy for conventional and hybrid-electric rotorcraft on energy, fuel, and emissions footprint. A multidisciplinary simulation framework for rotorcraft performance combined with models for engine performance and gaseous emissions estimation is deployed. A holistic optimization approach is developed for the derivation of globally optimal schedules for combined rotor speed and power split targeting minimum energy consumption. Application of the derived optimal schedules at mission level resulted to a 6% improvement in range capability for the VRS tilt-rotor relative to its conventional counterpart. For the hybrid-electric tilt-rotor, combined optimization of VRS and power management leads to an increase in range to 18.4% at 40% and 25% reduced payload for current (250 Wh/kg) and future (450 Wh/kg) battery technology, respectively. For representative Urban Air Mobility (UAM) scenarios, it is demonstrated that the VRS concept resulted in up to 10% and 14% reductions in fuel burn and NOX relative to the nominal rotor speed case, respectively. The utilization of the combined optimum VRS and power split schedules can boost performance with reductions of the order of 20%and 25% in mission fuel/CO2 and NOX at a reduced payload relative to the conventional tilt-rotor.

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Analysis of low-speed height-velocity diagram of a variable-speed-rotor helicopter in one-engine-failure

Cited by 18 publications

References 10 publications

Propeller control for takeoff of a heavily loaded coaxial compound helicopter

Propeller control for takeoff of a heavily loaded coaxial compound helicopter

Optimised Tuning of a PID-Based Flight Controller for a Medium-Scale Rotorcraft

On the Effects of Optimal Implementation of Variable Rotor Speed and Power Management on Hybrid-Electric Rotorcraft

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