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Feasibility analysis of angles-only navigation algorithm with multisensor data fusion for spacecraft noncooperative rendezvous

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Astrodynamics 2023年第2期7卷 179-196页

作者： Ronghua Du wenhe liao Xiang Zhang Micro/Nano Satellite Research Center Nanjing University of Science and TechnologyNanjing 210094China

Relative navigation is crucial for spacecraft noncooperative rendezvous,and angles-only navigation using visible and infrared cameras provides a feasible ***,an angles-only navigation algorithm with multisensor data fusion is proposed to derive the relative motion states between two noncooperative ***,the design model of the proposed algorithm is introduced,including the derivation of the state propagation and measurement ***,models for the sensor and actuator are introduced,and the effects of various factors on the sensors and actuators are *** square-root unscented Kalman filter is used to design the angles-only navigation filtering ***,the Clohessy-Wiltshire terminal guidance algorithm is introducedto obtain the theoretical relative motion trajectories during the rendezvous operations of two noncooperative ***,the effectiveness of the proposed angles-only navigation algorithm is verified using a semi-physical simulation *** results prove that an optical navigation camera combined with average accelerometers and occasional orbital maneuvers is feasible for spacecraft noncooperative rendezvous using angles-only navigation.

关键词： angles-only navigation feasibility analysis multisensor data fusion spacecraft noncooperative rendezvous

Calibration of robotic drilling systems with a moving rail

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Chinese Journal of Aeronautics 2014年第6期27卷 1598-1604页

作者： Tian Wei Zeng Yuanfan Zhou Wei liao wenhe College of Mechanical and Electronical Engineering Nanjing University of Aeronautics and Astronautics

Industrial robots are widely used in aircraft assembly systems such as robotic drilling systems. It is necessary to expand a robot＇s working range with a moving rail. A method for improving the position accuracy of an automated assembly system with an industrial robot mounted on a moving rail is proposed. A multi-station method is used to control the robot in this study. The robot only works at stations which are certain positions defined on the moving rail. The calibration of the robot system is composed by the calibration of the robot and the calibration of the *** calibration of the robot is based on error similarity and inverse distance weighted *** calibration of the stations is based on a magnetic strip and a magnetic sensor. Validation tests were performed in this study, which showed that the accuracy of the robot system gained significant improvement using the proposed method. The absolute position errors were reduced by about 85%to less than 0.3 mm compared with the maximum nearly 2 mm before calibration.

关键词： Aircraft assembly Calibration Error compensation Robotic drilling Robotics

Economic Design of  & S Control Charts Based on Taguchi's Loss Function and Its Optimization

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Chinese Journal of Mechanical Engineering 2012年第3期25卷 576-586页

作者： GUO Yu YANG Wen'an liao wenhe GAO Shiwen College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210013China China Aerospace of Science and Technology Corporation Beijing 100037China

Much research effort has been devoted to economic design of X ＆ S control charts,however,there are some problems in usual *** the one hand,it is difficult to estimate the relationship between costs and other model parameters,so the economic design method is often not effective in producing charts that can quickly detect small shifts before substantial losses occur;on the other hand,in many cases,only one type of process shift or only one pair of process shifts are taken into consideration,which may not correctly reflect the actual process *** improve the behavior of economic design of control chart,a cost ＆ loss model with Taguchi＇s loss function for the economic design of X ＆ S control charts is embellished,which is regarded as an optimization problem with multiple statistical *** optimization design is also carried out based on a number of combinations of process shifts collected from the field operation of the conventional control charts,thus more hidden information about the shift combinations is mined and employed to the optimization design of control *** the same time,an improved particle swarm optimization（IPSO） is developed to solve such an optimization problem in design of X ＆ S control charts,IPSO is first tested for several benchmark problems from the literature and evaluated with standard performance *** results show that the proposed algorithm has significant advantages on obtaining the optimal design parameters of the *** proposed method can substantially reduce the total cost（or loss） of the control charts,and it will be a promising tool for economic design of control charts.

关键词： statistical process control control charts Taguchi's loss function optimization particle swarm optimization

Hole surface strengthening mechanism and riveting fatigue life of CFRP/aluminum stacks in robotic rotary ultrasonic drilling

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Chinese Journal of Aeronautics 2023年第10期36卷 471-484页

作者： Song DONG wenhe liao Kan ZHENG Feng XUE Lianjun SUN School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Carbon fiber reinforced plastic(CFRP)and aluminum stacks are widely used in aviation industry due to light weight and high *** of rivet holes need to be drilled on body materials,and more than 80%of fatigue cracks occur at the connection holes,so the damage and residual stress of hole surface have crucial effect on the riveting fatigue life of CFRP/aluminum stacks and the flight ***,robotic rotary ultrasonic drilling(RRUD)technology is a promising method to machine the ***,the hole surface strengthening mechanism in RRUD and the service performance of the riveting joint are not ***,in this paper,the hole surface strengthening mechanism of RRUD for CFRP/aluminum stacks is investigated,a theoretical residual stress model is established,and the fatigue life experiment of riveted joints is ***,analysis on residual stress in RRUD is carried out with consideration of strengthening force and cutting *** stress model is established based on the calculation of elastic stress,plastic stress and stress *** experiment results show that ultrasonic vibration changes residual stress from tensile stress to compressive *** the same time,comparative damage analysis of CFRP hole exit and hole surface in robotic conventional drilling(RCD)and RRUD is ***,fatigue strength experiments of riveted joints are conducted for performance *** results indicate that fatigue life of single-hole riveted joints is increased by 68%with ultrasonic vibration,and four-hole riveted joint arranged according to aerospace design standards is increased by more than 86%.

关键词： CFRP/aluminum stacks Drilling damage Residual stress Riveting fatigue life Robotic rotary ultrasonic drilling

Ignition processes and characteristics of charring conductive polymers with a cavity geometry in precombustion chamber for applications in micro/nano satellite hybrid rocket motors

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Defence Technology（防务技术） 2024年第2期32卷 55-66页

作者： Zhiyuan Zhang Hanyu Deng wenhe liao Bin Yu Zai Yu Nanjing University of Science and Technology Nanjing 210094China

The arc ignition system based on charring polymers has advantages of simple structure,low ignition power consumption and multiple ignitions,which bringing it broadly application prospect in hybrid propulsion system of micro/nano ***,charring polymers alone need a relatively high input voltage to achieve pyrolysis and ignition,which increases the burden and cost of the power system of micro/nano satellite in practical *** conductive substance into charring polymers can effectively decrease the conducting voltage which can realize low voltage and low power consumption repeated ignition of arc ignition *** this paper,a charring conductive polymer ignition grain with a cavity geometry in precombustion chamber,which is composed of PLA and multiwall carbon nanotubes(MWCNT)was *** detailed ignition processes were analyzed and two different ignition mechanisms in the cavity of charring conductive polymers were *** ignition characteristics of charring conductive polymers were also investigated at different input voltages,ignition grain structures,ignition locations and injection schemes in a visual ignition *** results demonstrated that the ignition delay and external energy required for ignition were inversely correlated with the voltages applied to ignition ***,the incremental depth of cavity shortened the ignition delay and external energy required for ignition while accelerated the propagation of *** the depth of cavity increased from 2 to 6 mm(at 50 V),the time of flame propagating out of ignition grain changed from 235.6 to 108 ms,and values of mean ignition delay time and mean external energy required for ignition decreased from 462.8 to 320 ms and 16.2 to 10.75 J,*** rear side of the cavity was the ideal ignition position which had a shorter ignition delay and a faster flame propagation speed in comparison to other ignition *** to direct injection scheme,swirlin

关键词： Micro/nano satellite hybrid propulsion Arc ignition Charring conductive polymer Ignition mechanism Ignition characteristic Repeated ignition

Investigation on ignition characteristics of charring conductive polymers stimulated by electric energy

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Chinese Journal of Aeronautics 2024年第10期37卷 68-82页

作者： Zhiyuan ZHANG Hanyu DENG wenhe liao Yantao PU Ping CAO School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China Anhui Hongxing Electrical Polytron Technologies Inc. Hefei 231135China

The arc ignition based on charring conductive polymers has advantages of simple structure,low ignition power consumption and restart capacity,which bringing it broadly application prospect in hybrid propulsion system of micro/nano *** order to optimize the performance of arc ignition system,it is essential to have a deeper understanding of the ignition processes and ignition characteristics of charring conductive *** this paper,the thermal decomposition,electrical conductivity and thermal conductivity characteristics of charring conductive polymers with different conductive additives and matrix materials were comprehensively *** experimental investigation was conducted to determine the ignition behaviors and characteristics of different charring conductive polymers in a visual ignition *** experiment result showed that the ignition delay and external energy required for ignition are negatively correlated with voltage and initial temperature of the ignition grain,but positively correlated with oxidizer flow *** with charring conductive polymers containing multi-walled carbon nanotube,the ignition delay of charring conductive polymers with carbon black is significantly higher and the pyrolysis time is relatively ***,the ignition and initial flame propagation of charring conductive polymers with carbon black is more violent and more inclined to carbon particle ***,the restart characteristic of different charring conductive polymers was *** ignition delay and external energy required for ignition of different charring conductive polymers all reduced with the increasing of the number of ***,the ignition characteristics would not change a lot after repeated ignition.

关键词： Micro/nano satellite hybrid rocket motors Arc ignition Charring conductive polymer Ignition process Ignition characteristic Restart characteristic

Auto-normalization algorithm for robotic precision drilling system in aircraft component assembly

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Chinese Journal of Aeronautics 2013年第2期26卷 495-500页

作者： Tian Wei Zhou Weixue Zhou Wei liao wenhe Zeng Yuanfan College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

A novel approach is proposed to detect the normal vector to product surface in real time for the robotic precision drilling system in aircraft component assembly, and the auto-normalization algorithm is presented based on the detection system. Firstly, the deviation between the normal vector and the spindle axis is measured by the four laser displacement sensors installed at the head of the multi-function end effector. Then, the robot target attitude is inversely solved according to the auto-normalization algorithm. Finally, adjust the robot to the target attitude via pitch and yaw rotations about the tool center point and the spindle axis is corrected in line with the normal vector simultaneously. To test and verify the auto-normalization algorithm, an experimental platform is established in which the laser tracker is introduced for accurate measurement. The results show that the deviations between the corrected spindle axis and the normal vector are all reduced to less than 0.5°, with the mean value 0.32°. It is demonstrated the detection method and the autonormalization algorithm are feasible and reliable.

关键词： Aircraft assembly Auto-normalization Industrial robots Normal vector detection Robotic precision drilling

Investigation of the Laser Powder Bed Fusion Process of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloy

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Chinese Journal of Mechanical Engineering 2023年第2期36卷 78-90页

作者： Changchun Zhang Tingting Liu wenhe liao Huiliang Wei Ling Zhang School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Mechanical and Vehicle Engineering West Anhui UniversityLuan 237012China

Laser powder bed fusion(LPBF)is an advanced manufacturing technology;however,inappropriate LPBF process parameters may cause printing defects in *** the present work,the LPBF process of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy was investigated by a two-step optimization ***,heat transfer and liquid flow behaviors during LPBF were simulated by a well-tested phenomenological model,and the defect formation mechanisms in the as-fabricated alloy were *** optimized process parameters for LPBF were detected as laser power changed from 195 W to 210 W,with scanning speed of 1250 mm/*** LPBF process was divided into a laser irradiation stage,a spreading flow stage,and a solidification *** morphologies and defects of deposited tracks were affected by liquid flow behavior caused by rapid cooling *** findings of this research can provide valuable support for printing defect-free metal components.

关键词： Laser powder bed fusion Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy Process parameters Heat transfer and liquid flow Defects

Improvement of Orbit Prediction Algorithm for Spacecraft Through Simplified Precession-Nutation Model Using Cubic Spline Interpolation Method

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Computer Modeling in Engineering & Sciences 2020年第11期125卷 865-878页

作者： Gen Xu Danhe Chen Xiang Zhang wenhe liao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210097China

For the on-orbit flight missions,the model of orbit prediction is critical for the tasks with high accuracy requirement and limited computing resources of *** precession-nutation model,as the main part of extended orbit prediction,affects the efficiency and accuracy of on-board *** this paper,the previous research about the conversion between the Geocentric Celestial Reference System and International Terrestrial Reference System is briefly summarized,and a practical concise precession-nutation model is proposed for coordinate transformation computation based on Celestial Intermediate Pole(CIP).The idea that simplifying the CIP-based model with interpolation method is driven by characteristics of precession-nutation parameters changing with time.A cubic spline interpolation algorithm is applied to obtain the required CIP coordinates and Celestial Intermediate Origin *** complete precession nutation model containing more than 4000 parameters is simplified to the calculation of a cubic polynomial,which greatly reduces the computational *** addition,for evaluating the actual performance,an orbit propagator is built with the proposed simplified *** with the orbit prediction results obtained by the truncated series of IAU2000/2006 precession-nutation model,the simplified precession-nutation model with cubic spline interpolation can significantly improve the accuracy of orbit prediction,which implicates great practical application value in further on-orbit missions of spacecraft.

关键词： Orbit prediction CIP-based coordinate transformation cubic spline interpolation