Nose Wheel Steering Research Articles

Force-Fighting Phenomena and Disturbance Rejection in Aircraft Dual-Redundant Electro-Mechanical Actuation Systems

This paper presents a robust control system that addresses two key challenges in redundant actuators using Permanent Magnet Synchronous Motors (PMSM) for an aircraft nose wheel steering system: the elimination of force-fighting phenomena and the ability to respond effectively to unexpected disturbances. In detail, a control method was devised to enhance the mitigation of force-fighting phenomena and disturbances by accurately observing and compensating for the torque-induced load applied to the PMSM. This was achieved through the utilization of a Q-filter-based Disturbance Observer (DOB). The proposed control approach was implemented and evaluated on a redundant system consisting of the PMSM and the nose wheel steering system. The performance of the proposed method was verified through extensive simulation studies. The simulation results confirmed the effectiveness and reliability of the method in accurately observing and responding to the force-fighting phenomenon that occurs in the redundant driving device. By subjecting the system to various scenarios and disturbances, the simulation provided a comprehensive evaluation of the proposed method’s ability to handle force-fighting phenomena. The results demonstrated that the method successfully observed and responded to the force-fighting phenomenon, thereby mitigating its adverse effects on the system’s performance. Therefore, these outcomes serve as empirical evidence supporting the validity and efficiency of the proposed method in addressing the force-fighting phenomenon encountered in the redundant driving device. These findings substantiate the effectiveness of the proposed approach and its potential for practical implementation in real-world systems.

Low-visibility commercial ground operations: An objective and subjective evaluation of a multimodal display

AbstractFlight crews’ capacity to conduct take-off and landing in near zero visibility conditions has been partially addressed by advanced surveillance and cockpit display technology. This capability is yet to be realised within the context of manoeuvring aircraft within airport terminal areas. In this paper the performance and workload benefits of user-centre designed visual and haptic taxi navigational cues, presented via a head-up display (HUD) and active sidestick, respectively, were evaluated in simulated taxiing trials by 12 professional pilots. In addition, the trials sought to examine pilot acceptance of side stick nose wheel steering. The HUD navigational cues demonstrated a significant task-specific benefit by reducing centreline deviation during turns and the frequency of major taxiway deviations. In parallel, the visual cues reduced self-report workload. Pilot’s appraisal of nose wheel steering by sidestick was positive, and active sidestick cues increased confidence in the multimodal guidance construct. The study presents the first examination of how a multimodal display, combining visual and haptic cues, could support the safety and efficiency in which pilots are able to conduct a taxi navigation task in low-visibility conditions.

Shock Absorber Leakage Impact on Aircraft Lateral Stability During Ground Handling Maneuvers

Aircraft braking maneuvers are safety-critical on-ground motions that exhibit complex dynamics and significant dependence on system operating conditions. The fundamental interface between the aircraft and the ground is the landing gear. Among the landing gear components, the shock absorbers may be subject to gas leakage during their lifetime, which is an anomaly that could compromise the lateral stability properties of the aircraft on the operating regimes found during braking maneuvers. In this paper, an explicit link is established between main landing gear shock absorber leakage and aircraft lateral stability. To investigate lateral stability, a high-fidelity multibody nonlinear aircraft simulator is developed in a MATLAB/Simulink framework and validated against experimental data. To generate insight into the problem and to quantify shock absorber leakage impact on aircraft lateral stability, two simple but descriptive analytical models are also developed, each one on a different operating mode of the system. The analysis of the models reveals that shock absorber leakage can have a significant effect on aircraft lateral stability, especially at high velocities and highly damped nose wheel steering conditions. The models developed in this work may be used by aircraft control system designers to come up with more effective lateral stability controllers in the event of main landing gear shock absorber leakage.

Simulation of the hydraulic steering device, for a nose landing gear

The hydraulic steering simulation is done with SIMULINK, part of the MathWorks MATLAB® application. All parts, subassemblies, and assemblies that define the nose landing gear (NLG) and nose wheel steering are fully defined in 3D, with CATIA V5 - a computer-aided design software used for modeling, it is possible to carry out simulations that allow preliminary evaluation, theoretically and experimentally. The purpose of this simulation is to confirm the correctness of the steering gear kinematics, that the two hydraulic cylinders have been sized correctly and can overcome the resistive steering moment, and that the steering time complies with design specifications for the nose landing gear of a military training aircraft.

Design and Simulation Analysis of an Electromagnetic Damper for Reducing Shimmy in Electrically Actuated Nose Wheel Steering Systems

Based on the technical platform of electrically actuated nose wheel steering systems, a new type of damping shimmy reduction technology is developed to break through the limitations of traditional hydraulic damping shimmy reduction methods, and an electrically actuated nose wheel steering structure scheme is proposed. The mathematical model of the electromagnetic damper is established, the derivation of skin depth, damping torque and damping coefficient is completed, and the design of the shape and size of the electromagnetic damper is combined with the derivation results and the technical index of shimmy reduction. The electromagnetic field finite element simulation results show that the mathematical modeling method of the electromagnetic damper has good accuracy, and its application to the shimmy reduction module of the electrically actuated nose wheel steering system is also feasible and superior. Finally, the key factors influencing the performance of electromagnetic damper shimmy reduction are studied and analyzed, thus forming a complete electromagnetic damper shimmy reduction technology for the electrically actuated system, and laying the foundation for the design of novel all-electric aircraft and landing gear.

ANALISIS KEGAGALAN NOSE WHEEL STEERING SYSTEM PADA PESAWAT BOEING DENGAN MENGGUNAKAN METODE FAILURE MODE AND EFFECT ANALISYS

Aircfrat use nose wheel steering system when landing, take off and landing. In the research discuses the problem of nose wheel steering system B737 – 800 to minimize problems ini nose wheel steering system. The stage of this research are to study the work system of nose wheel steering. Then look for the cause of the problem using the FMEA analysis method. This research is based on data from AFML (aircraft Flight and Manual Log) of the B737 – 800 Aircraft from January 2020 to Junu 2021 at Lion Airline. The results showed that the problem of nose wheel steering system in the failure mode analysis process using FMEA method data in the highest RPN ( Risk priority Number) value is 175 with the case steering collar dan torQ link need lubrication and case Tire pressure that caused by the lack of lubrication on the component and different pressure in tire. Then it is necessary to do inspection before flight.

Design and co-simulation of a nose wheel steering system for a civil aircraft

In order to automate the ground maneuvering of a civil regional aircraft and improve the efficiency of the air transport system, a fly-by-wire nose wheel steering system (NWSS) was designed. A rack and pinion steering mechanism integrated with a single actuator mechanism was proposed. The basic control circuit diagram with integrated test, the electro-hydraulic system diagram, and the mathematical model of the steering system were established and analyzed. A co-simulation model of the system was built to verify the control law. The results show that the properties of the prototype meet the design requirements. Given the importance of the NWSS, the simulation results can be used to optimize the basic design parameters. This methodology can also be used for other types of aircraft.

Research into Nose Wheel Steering Deviation Angle Calculation of a Civil Aircraft

This document, based on a civil aircraft, describes the basic principle of nose wheel steering deviation angle calculation. The taxiing deviation angle of aircraft in ground test can be balanced by adjusting the nose wheel angle, but the deviation angle cannot be read directly, it needs to be calculated according to the field data. In this paper, we research a method to calculate the deviation angle by try three different modelling: simplified point modelling, calculus modelling and trigonometric modelling. Finally, we find the third modelling is more practical, we can rectified the deviation angle by adjusting the nose wheel turning control system pre-set parameters according with the result. We also transform the mathematic modelling into a computer program, to improve the efficiency in practical use.

A simple and efficient control allocation scheme for on-ground aircraft runway centerline tracking

To achieve a high performance level during ground operations, the lateral dynamics of an aircraft must be controlled using all available actuators (rudder, nose-wheel steering system, engines and brakes) and under various constraints, which gives rise to a challenging allocation problem. To address this issue, a simple yet accurate design-oriented on-ground aircraft model is first developed. It takes into account the effects of aerodynamics, thrust and tire–ground interactions, both laterally and longitudinally, and for several runway states. It is validated on a high-fidelity Airbus simulator and a complete set of numerical values representative of a commercial aircraft is given, as well as design objectives, so as to provide the control community with a challenging benchmark. After an extensive literature review and an evaluation of the pros and cons of many existing control allocation techniques, a novel and easily implementable algorithm is then developed, which meets actuator and implementation constraints. It automatically manages the trade-off between two antagonistic objectives, namely minimizing the control effort and attaining the maximum virtual control. Its validation on both the design-oriented model and the high-fidelity simulator shows promising results.

Multifidelity Data Fusion: Application to Blended-Wing-Body Multidisciplinary Analysis Under Uncertainty

This paper presents a methodology to support improved decision making and identification of risks in early stage multidisciplinary design. The approach fuses multifidelity data from disparate information sources available to designers, such as disciplinary simulations, experiments, and operational data from previously deployed systems. The multifidelity data fusion is achieved using a fidelity-weighted combination of Gaussian process surrogate models. This weighting takes into account both the quality of the Gaussian process approximation and the designer’s confidence in the underlying information source being approximated. The resulting multifidelity surrogate provides a rapid analysis capability, which in turn enables the high number of evaluations needed to conduct multidisciplinary trade studies and to propagate uncertainty to the overall system level. The methodology is broadly applicable across engineering design problems where multiple information sources are available to support design decisions. In this paper, the approach is demonstrated on the stability and control analysis of a Blended-Wing-Body aircraft’s center-of-gravity limits, considering the longitudinal criteria of fly-to-stall, stall recovery, nose-wheel steering, and nose-wheel liftoff. The results show that low-fidelity models are enhanced by the presence of higher-fidelity data in key areas of the design space. The presence of even sparse high-fidelity data is key to reducing the variance in the overall analysis, thereby improving the quality of the predictions needed to inform early stage design decisions.

A new control allocation algorithm to improve runway centerline tracking at landing

Abstract To achieve a high performance level during ground operations, the lateral dynamics of an aircraft must be controlled using all available actuators (rudder, nose wheel steering system and brakes), which gives rise to a challenging allocation problem. After an extensive literature review and evaluation of the most promising techniques, a novel and easily implementable control allocation technique is developed, which meets actuator and implementation constraints. It automatically manages the trade-off between minimizing actuator use and attaining the maximum virtual control. It is tested on a realistic on-ground aircraft model, which has been previously validated against a high-fidelity Airbus simulator.

Design and Analysis of All-electric Aircraft Nose Wheel Steering System Based on Intelligent Algorithm

As all-electric aircraft has many advantages, aircraft nose wheel steering system would be developed to the all-electric direction. Aiming at the control demand of nose wheel steering system, based on the basic principles of nose wheel steering system and the design technique of mechanotronics, an all-electric aircraft nose wheel steering system composed of a nose wheel steering mechanism of two worm gear and a control servo system of fly-by-wire having both steering and anti-shimmy function is designed to meet the demand for operation control in nose wheel steering system. Besides, the fuzzy algorithm and BP neural network algorithm is applied to the control system to explore its algorithm. Then based on Matlab/Simulink and LMS/AMESim software, the united simulation model of the system with fuzzy PID controller is established to make the dynamic simulation analysis for the verification of its steering function, the research results indicate that the nose wheel steering system is reasonable and validated, can meet the requirements of the general project.

Design and Test of Dual Actuator Nose Wheel Steering System for Large Civil Aircraft

In order to improve aircraft ground handling characteristics and airport working efficiency, large handling angle and torque are requested for the nose wheel steering system of large civil aircraft. A following swivel selector valve is firstly designed to meet the demand for the hydraulic pressure commutating as soon as the dual actuator nose wheel steering mechanism passes through its dead center position. Considering the multiple objective functions of nose wheel steering mechanisms, those core design parameters are multiobjective optimized. A nose wheel steering electrohydraulic servo system with handling and antishimmy functions is designed for the steering mechanism. Then the prototypes of the steering mechanism and electrohydraulic servo system are researched to validate the design. Using the swing actuator to provide the load torque and ground excitation, the steering test bench is prepared to test the system working. The steering test and the antishimmy test are conducted to verify the functions of the system. The test results, such as steer angle, steer torque hydraulic pressure, and antishimmy torque, are analyzed in detail and compared with the theoretical results. The results show that the property of the prototype achieves the design objectives, such as work mode, steer angle, and steer torque.

A study of instability in a miniature flying-wing aircraft in high-speed taxi

This study investigates an instability that was observed during high-speed taxi tests of an experimental flying-wing aircraft. In order to resolve the reason of instability and probable solution of it, the instability was reproduced in simulations. An analysis revealed the unique stability characteristics of this aircraft. This aircraft has a rigid connection between the nose wheel steering mechanism and an electric servo, which is different from aircraft with a conventional tricycle landing gear system. The analysis based on simulation results suggests that there are two reasons for the instability. The first reason is a reversal of the lateral velocity of the nose wheel. The second reason is that the moment about the center of gravity created by the lateral friction force from the nose wheel is larger than that from the lateral friction force from the main wheels. These problems were corrected by changing the ground pitch angle. Simulations show that reducing the ground pitch angle can eliminate the instability in high-speed taxi.

A directional control system for UCAV automatic takeoff roll

PurposeThe purpose of this paper is to develop a directional and roll control system for unmanned combat air vehicle (UCAV) automatic takeoff roll, with the objective of keeping the UCAV along the runway centerline and keeping the wings level, especially when there is a crosswind.Design/methodology/approachThe nonlinear model of the UCAV during takeoff roll is established. The model is linearized about the lateral‐directional equilibrium point at different forward speeds. The approximate directional model and roll model are extracted using time‐scale decomposition technique. Then the directional control law and roll control law are developed using gain scheduling approach. Nose wheel steering, differential brake and rudder are used as the primary directional control device at low, medium and high speeds, respectively, according to both the qualitative and quantitative analysis of their control effectiveness at different speeds. A priority matrix is developed to determine the secondary control device which is used if the primary control device fails, thus the directional control system can have a certain degree of fault tolerance.FindingsThis work developed the directional control law and roll control law by using gain scheduling approach. Experimental results verified that the developed directional and roll control system has high robustness and satisfactory fault tolerance: it can guarantee a safe takeoff under a 50 ft/sec crosswind, even if one directional control device fails, which satisfies the relevant criteria in MIL‐HDBK‐1797.Practical implicationsThe directional and roll control system developed can be easily applied to practice and can steer the UCAV during takeoff roll safely, which will considerably increase the autonomy of the UCAV.Originality/valueThe paper shows how time‐scale decomposition technique is employed to extract the approximate directional model and roll model, which simplifies model analysis and control law design. A fault‐tolerant directional control system is designed to improve safety during takeoff.

Development and validation of on‐board systems control laws

PurposeThe purpose of this paper is to describe the tool and procedure developed in order to design the control laws of several UAV (Unmanned Aerial Vehicle) sub‐systems. The authors designed and developed the logics governing: landing gear, nose wheel steering, wheel braking, and fuel system.Design/methodology/approachThis procedure is based on a general purpose, object‐oriented, simulation tool. The development method used is based on three‐steps. The main structure of the control laws is defined through flow charts; then the logics are ported to ANSI‐C programming language; finally the code is implemented inside the status model. The status model is a Matlab‐Simulink model, which uses an embedded Matlab‐function to model the FCC (Flight Control Computer). The core block is linked with the components, but cannot access their internal model. Interfaces between FCCs and system components in the model reflect real system ones.FindingsThe user verifies systems' reactions in real time, through the status model. Using block‐oriented approach, development of the control laws and integration of several systems is faster.Practical implicationsThe tool aims to test and validate the control laws dynamically, helping specialists to find out odd logics or undesired responses, during the pre‐design.Originality/valueThe development team can test and verify the control laws in various failure scenarios. This tool allows more reliable and effective logics to be produced, which can be directly used on the system.

A Safety Strategy for High-speed UAV Landing Taxiing Control

In terms of safety for landing taxiing control of high-speed unmanned air vechicles (UAVs), key safety-critical factors were first. A generic taxiing control logic was put forward, incorporating the concerned factors. For further verification, a nonlinear mathematic model was deduced with high accuracy for ground motion simulation, incorporating the characteristics of undercarriages, brake, nose wheel steering and runway condition. Simulations show that the control logic works well and provides sAttention:ufficient safety assurance in even extreme situations experienced.

Fault-tolerant electric drive for an aircraft nose wheel steering actuator

This study describes the design and testing of a dual-lane electric drive for a prototype, electromechanically actuated, nose wheel steering system for a commercial aircraft. The drive features two independent motor controllers, each operating one-half of a dual three-phase motor, resulting in an actuator capable of full performance following an electrical fault. An isolated communications link between controllers allows parameter consolidation to identify faults and to synchronise outputs, ensuring even load sharing. A selection of results is presented from motor dynamometer performance analysis and from fully loaded output tests, performed on a hydraulic load rig at Airbus, UK.

Modeling and simulation of aircraft anti‐skid braking and steering using co‐simulation method

PurposeThe purpose of this paper is to introduce a co‐simulation method to study the ground maneuvers of aircraft anti‐skid braking and steering.Design/methodology/approachA virtual prototype of aircraft is established in the multibody system dynamics software MSC.ADAMS/Aircraft. The anti‐skid braking control model, which adopts the multi‐threshold PID control method with a slip‐velocity‐controlled, pressure‐bias‐modulated (PBM) system, is established in MATLAB/Simulink. EASY5 is used to establish the hydraulic system of nose wheel steering. The ADAMS model is connected to block diagrams of the anti‐skid braking control model in MATLAB/Simulink, and is also connected to the block diagrams of nose wheel steering system model in EASY5, so that the ground maneuvers of aircraft anti‐skid braking and steering are simulated separately.FindingsResults are presented to investigate the performance of anti‐skid braking system in aircraft anti‐skid simulation. In aircraft steering simulation, the influence of two important parameters on the forces acting on the tires is discussed in detail, and the safe area to prevent aircraft sideslip is obtained.Originality/valueThis paper presents an advanced method to study the ground maneuvers of aircraft anti‐skid braking and steering, and establishes an integrated aircraft model of airframe, landing gear, steering system, and anti‐skid braking system to investigate the interaction of each subsystem via simulation.

DRESS: Distributed and Redundant Electro-mechanical Nose Wheel Steering System

DRESS: Distributed and Redundant Electro-mechanical Nose Wheel Steering System