Browse Topic: Energy consumption
This document covers the requirements for SAE implementations based on ISO 17987:2016. Requirements stated in this document will provide a minimum standard level of performance to which all compatible ECUs and media shall be designed. This will assure full serial data communication among all connected devices regardless of supplier.The goal of SAE J2602-1 is to improve the interoperability and interchangeability of LIN devices within a network by adding additional requirements that are not present in ISO 17987:2016 (e.g., fault tolerant operation, network topology, etc.).The intended audience includes, but is not limited to, ECU suppliers, LIN controller suppliers, LIN transceiver suppliers, component release engineers, and vehicle system engineers.The term “master” has been replaced by “commander” and term “slave” with “responder” in the following sections.
Helicopters' Vertical Take-Off and Landing (VTOL) capabilities are essential for maritime operations, especially for small-deck naval vessels. Unmanned Aerial Vehicles (UAVs) offer a cheaper, expendable, and efficient alternative for certain tasks, such as reducing pilot risk and lowering fuel consumption. While the procedures to approach and land on (moving) ships are standardized and bound to established operational limits in the case of crewed helicopters, UAVs lack such guidelines. This study investigates optimal rotary-wing UAV approach trajectories to a moving ship, for varying wind conditions and relative initial positions, and for different objectives. The goal is to provide preliminary guidelines for maritime UAV recovery operations, and a preliminary estimation of performance-based operational limits. The optimal trajectories are obtained using a global path-performance optimization framework based on Optimal Control Theory. The trajectories are compared to each other and to
The transition phase of eVTOL aircraft poses a challenge in balancing energy efficiency and stability. This study presents the development and evaluation of an automatic flight control system for eVTOL transition phases, focusing on minimizing energy consumption while ensuring robust performance. The control architecture implements a hybrid response type combining Translational Rate Command below 5 knots and Acceleration Command Speed Hold above 5 knots, with control allocation dynamically adjusted based on airspeed and rotor shaft angle. Stability analysis reveals surge mode instability at high shaft angles due to negative speed stability derivatives, stabilized through carefully tuned feedback control. The system demonstrates Level 1 handling qualities against bandwidth, quickness, and disturbance rejection criteria when evaluated against MIL-DTL-32742 and MIL-STD-1797B standards. Simulation results verify the control system's ability to maintain precise acceleration/deceleration
This study investigates the effects of chord-to-radius ratio (c/R) and blade count on the aerodynamic and aeroacoustic performance of cyclorotors through experimental testing and a low-fidelity streamtube model. Cyclorotors with c/R ratios between 0.3 to 0.75 and blade counts ranging from 5 to 9 were tested across pitch amplitudes up to 51°. For a 5-bladed configuration, the pitch amplitude that maximizes the force-to-power coefficient (CF/CP) increases with c/R from approximately 32° at low c/R to around 51° at high c/R. However, the peak attainable CF/CP decreases with increasing c/R, indicating a trade-off between optimal pitch amplitude and aerodynamic efficiency. Increasing blade count enhances the generated force but reduces efficiency in all cases except for the lowest c/R configuration (0.3). Aeroacoustic analysis shows that tonal noise is primarily driven by pitch amplitude and intensifies with increasing c/R, while additional blades effectively mitigate it. In contrast
Advanced Air Mobility (AAM) is an innovative concept that aims to revolutionize air transportation through electric and unmanned aircraft, enabling applications such as urban air taxis and medical transport. However, one of the key challenges to its widespread adoption is ensuring safety, particularly in collision avoidance. This study focuses on the development of a perception and guidance system for avoiding collisions with non-cooperative targets, which do not share their position or trajectory. To achieve this, a Frequency-Modulated Continuous Wave (FMCW) radar and an InfraRed(IR) camera are used. Compared to traditional pulsed or panel radars, FMCW radars offer higher resolution, better detection of small and slow-moving objects, and improved performance in cluttered environments. The IR camera enhances situational awareness by providing visual confirmation and additional tracking capability, making this sensor fusion approach particularly suitable for AAM applications. Our
Design modifications to a 3lb variant of DEVCOM Army Research Laboratory's Common Research Configuration (CRC-3) are assessed using simulation tools. To identify areas for improvement, the baseline CRC-3 is analyzed in hover and forward flight, and contributors to overall power consumption are identified, with the rotor drag consuming the greatest amount of power, due to the high rotational speeds required to maintain thrust in the face of the freestream velocity. Potential areas for improvement are identified as: wing airfoil, rotor blade pitch, and rotor orientation. Changing the airfoil has little to no measurable effect on the overall power consumption. Increasing the blade pitch improves cruise performance considerably, but at the cost of hover efficiency, for an overall range improvement of up to 28%. Changing the rotor orientation improves rotor efficiency as well, without substantial cost to hover power consumption, increasing the range by 37% but will require a redesign of the
The paper presents a novel strategy for minimum energy consumption in automatic conversion control of tiltrotor eVTOL aircraft, exemplified by the Aston Martin Volante Vision model. We introduce a tilt schedule methodology that strategically balances conversion and reconversion performance with climb, descent, and cruise phases to minimize overall energy expenditure. Our approach accounts for critical factors such as blade loading, operation handling qualities, and passenger ride comfort within a predefined conversion corridor. The optimized trajectories approximate the minimum energy pathway, essential for operational efficiency in urban air mobility. Analytical results demonstrate that our proposed conversion and reconversion phase profiles significantly reduce energy consumption, contributing to the sustainability of tiltrotor flight operations. This research not only enhances understanding of tiltrotor dynamics but also serves as a pivotal step toward achieving globally optimized
Unmanned Aerial Vehicles (UAVs), particularly Vertical Take-Off and Landing (VTOL) aircraft such as quad-rotors and helicopters, have gained attention for diverse applications in military and civilian domains. However, to increase applications, reducing their power consumption and their restricted payload capacity. This paper describes a method to enhance the thrust capabilities of typical shrouded rotors through a novel rotor design. Beginning with an airfoil with a high lift-to-drag ratio. Blade element momentum theory (BEMT) is used to optimize the rotor's chord and twist distributions systematically along with precise induced velocity prediction in shrouded rotors. Furthermore, a validation process requires rotor manufacturing and experimentation. BEMT harmonizes momentum and blade element theories, offering a comprehensive framework for rotor behavior modeling, especially in hovering conditions. First, second, and third degrees functions are used to express both the chord and
In over actuated aircrafts a simple relationship between control inputs and forces/moments generated does not exist, however they have become very attractive for their wide range of applications. Control allocation aims at finding a unique surface control distribution as function of flight condition to perform the desired maneuver. The goal of this paper is to present a control allocation methodology applied on a generic over actuated aircraft aimed to determine the surface gearing matrix weights in different operative conditions to minimize the total power consumption. First, the non-linear model of the control forces and moments is derived for an over actuated aircraft. Then, two different optimization problems are introduced: the first to compute the trim equilibrium for any flight condition to minimize power consumption by the aircraft; the second to minimize the surface deflections required to produce desired control forces/moments starting from the trim point previously found
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