Dynamics Model of Carrier-based Aircraft Landing Gears Landed on Dynamic Deck

In this work, we demonstrate the use of co-simulation technology in the maritime industry through four relevant examples of applications based on the outcome of the knowledge-building project Virtual Prototyping of Maritime Systems and Operations (ViProMa). Increasing computational capabilities opens for extended use of simulators in the design processes. Even complex systems can now be analyzed at an early stage of the design process and even in real time using distributed simulation technology. We conduct an assessment of the need for co-simulation technology in the industry, present a short background in co-simulation technology, and provide a short summary of the major findings and deliverables in the ViProMa project (
 http://viproma.no
 ). The four case studies presented in this work pinpoint different advantages of using co-simulations in the industry, such as combining different modeling and simulation tools, improving collaboration without revealing sensitive information by using black-box models, testing conceptual designs in a fast and consistent manner before initiating building processes, and verifying the interplay between hardware and software in the simulation environment in hardware in the loop (HIL) tests. All the case studies are simulated using the open source co-simulation software Coral developed in the project, using the Functional Mock-up Interface (FMI) standard, and the co-simulation software can be downloaded from the project’s web site.

Virtual prototyping of maritime systems and operations: applications of distributed co-simulations

In this paper a dynamic simulation methodology of systems is presented by using ADAMS/MATLAB co-simulation. This methodology allows simulation, development and validation of different control strategiesfor robotic manipulator models in a fast way. It provides a first stage into the design of robotic prototypes for researchers and professionals. Finally, the methodology was validated by constructing a simulation model of a double pendulum and by implementing a PD type control strategy.

ADAMS/MATLAB Co-Simulation: Dynamic Systems Analysis and Control Tool

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.

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

On the numerical stability in dynamical distributed simulations

Purpose – The 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/approach – A 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.Findings – Results are presented to investigate the performance of anti‐skid braking system in aircraft anti‐skid simulation. In aircraft steering simulation, the influence ...

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

The conception of landing area is introduced to the aircraft carrier, and a simplified model of the conventional oleo-pneumatic landing gear during the process of landing impact on the landing area is established. The mathematic model is also derived. The dynamic response of the landing gear landing vertically is calculated via Runge-Kutta procedure. Simulation results for both the original model and the new model are presented to illustrate the effectiveness of the new model. The result shows that the maximum of the impact loads on airframe and the maximal ground reaction force are reduced 37.3% and 37.2% respectively.

New Method of Attenuating Landing Impact Force on Carrier-based Aircraft Landing Gear

In this paper, the fault analysis of an aircraft nose landing gear’s emergency lowering was conducted with a cosimulation method. The simulation was aimed at studying the dynamic response characteristics of landing-gear retraction/extension. Moreover, the equations of the mechanical and hydraulic system were derived and analyzed so as to acquire the boundary condition under which the landing-gear emergency lowering could fail. Based on the simulation platform computer aided engineering, a cosimulation model (including a dynamic system and a hydraulic system) was developed, after which, by comparing the simulation results with the data of the ground test and flight test, the model was further verified. Additionally, the nose landing gear could succeed in emergency lowering with the premise that the critical dampings of different flight cases and temperatures were obtained. After that, a feasible scheme of emergency lowering was put forward. The results showed that, at the end of the landing-gear lowering p...

Fault Analysis and Solution of an Airplane Nose Landing Gear’s Emergency Lowering

The vibration of a nose landing gear caused by the sudden discharge of holdback load during the catapult launch of a carrier-based aircraft could bring serious fatigue both to the structure of the launch and the airborne equipment.To investigate the vibration and seek a solution,a dynamic model of the catapult launch is established.The load of the nose landing gear is calculated,while the kinetics and the way to deal with the phenomenon is also discussed in detail.From the catapult launch calculation,three important conclusions are obtained: during the tension stage,there is a long stroke and aft bending of the nose landing gear;once the holdback load suddenly discharges,the landing gear strut extends and springs forward rapidly;the fore-aft vibration of the nose landing gear produces a rapid and drastic load change at the joint of the gear and the fuselage.This vibration load has an adverse effect on the life and safety of the structure and the equipment of the aircraft.The length of the holdback bar influences the load along the lower torque link directly,and reducing this load has an obvious effect on the reduction of the vibration after a sudden discharge of the holdback load.

Wei Xiaohui

Papers

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

New Method of Attenuating Landing Impact Force on Carrier-based Aircraft Landing Gear

Fault Analysis and Solution of an Airplane Nose Landing Gear’s Emergency Lowering

Analysis on the Dynamic Characteristics of Carrier-based Aircraft Nose Landing Gear with Sudden Holdback Load Discharge