The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle(AUV)retrieval and release.This study aims to develop a capture mechanism for the l...The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle(AUV)retrieval and release.This study aims to develop a capture mechanism for the launch and recovery of AUV and elucidate its kinematic characteristics.Initially,based on the principles of deployment and retraction for AUV capture movements,a design scheme for a novel foldable and deployable capture mechanism is proposed.Subsequently,a detailed analysis of the Degrees of Freedom(DoFs)for enveloping and grasping movements is conducted according to screw theory.Additionally,the structural design of the actuation units for the capture mechanism is thoroughly discussed.Motion screw topology diagram is utilized to construct the kinematic model.On this basis,kinematic simulation verification of the capture mechanism is performed.The theoretical analysis revealed that the DoF for enveloping and grasping movements are 6 and 2,respectively.By appropriately configuring the actuation mechanism,enveloping and grasping movements can be achieved with a single actuation.The displacement and velocity curves of the capture mechanism were smooth,with no interference occurring.Vibration test results validate the reliability of the capture mechanism.The research work provides a valuable reference for the development of novel capture equipment for AUVs.展开更多
Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the...Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the capture of flexible, small animals with complex locomotor behaviors, the markers interfere with each other easily, and the motion forms(bending, twisting) of the moving parts are obviously different;thus, it is a great challenge to realize accurate quantitative characterization of complex locomotor behaviors. The correlation between the marker properties, including the size and space length, and the precision of the system are revealed in this paper, and the effects of diverse marker shapes on the capturing accuracy of the captured objects in different motion forms were tested. Results showed that the precision of system is significantly improved when the ratio of the space length to the diameter of the markers is larger than four;for the capture of the spatial twisting motion of the flexible object, the hexagon markers had the lowest spatial lost-marker rate relative to the circle, triangle, and square. Customized markers were used to capture the locomotor behavior of the gecko-inspired robot(rigid connection) and the gecko(flexible connection). The results showed that this marking technology can achieve high accuracy of motion capture for geckos(the average deviation was approximately 0.32 mm, and the average deviation’s variation rate was approximately 0.96%). In this paper, the marking technology for the motion capture of flexible, small animals with complex motion is proposed;it can effectively improve the system precision as well as the capture accuracy, and realize the quantitative characterization of the complex motion of flexible, small objects. It provides a reliable technical means to deeply study the evolution of the motion function of small animals and advance systematic research of motion-capture technology.展开更多
In order to high reality and efficiency, the technique computer animation. With the development of motion capture, a of motion capture （MoCap） has been widely used in the field of large amount of motion capture data...In order to high reality and efficiency, the technique computer animation. With the development of motion capture, a of motion capture （MoCap） has been widely used in the field of large amount of motion capture databases are available and this is significant for the reuse of motion data. But due to the high degree of freedoms and high capture frequency, the dimension of the mo- tion capture data is usually very high and this will lead to a low efficiency in data processing. So how to process the high dimension data and design an efficient and effective retrieval approach has become a challenge which we can＇t ignore. In this paper, first we lay out some problems about the key techniques in motion capture data processing. Then the existing approaches are analyzed and sum- marized. At last, some future work is proposed.展开更多
Accurate motion prediction of free-tumbling satellites is crucial for the success of capture operations.This paper proposes a two-step method to estimate the motion states and parameters of such satellites,thereby ena...Accurate motion prediction of free-tumbling satellites is crucial for the success of capture operations.This paper proposes a two-step method to estimate the motion states and parameters of such satellites,thereby enabling precise long-term motion prediction.This paper begins with a measurement of the system's degree of observability,quantified through the Empirical Observability Gramian(EOG).Based on this measurement,a batch processing algorithm is first employed to estimate the satellite's constant parameters offline.Subsequently,an online filtering algorithm,utilizing a minimal state set,fine-tunes these parameters and estimates the motion states in real time.This integrated approach significantly enhances both convergence properties and estimation accuracy,particularly for systems with poor observability.Utilizing the predicted long-term motion of the satellite,a composite evaluation metric is formulated to identify the optimal capture point and moment.The base pose of the space robot is then adjusted to ensure that the optimal capture point lies within the manipulator's dexterous workspace,which is determined through a pre-constructed capability map.The effectiveness of the proposed method is demonstrated through both simulation and experimental results.展开更多
Concerning the capture problem against arbitrary maneuvering targets,whose overload is high maneuvering but upper bounded and velocity has advantages,this paper elucidates a three-dimensional multi-constraint analytic...Concerning the capture problem against arbitrary maneuvering targets,whose overload is high maneuvering but upper bounded and velocity has advantages,this paper elucidates a three-dimensional multi-constraint analytical capture zone,exhibiting prominent guiding significance to the initial states of the terminal guidance.Unlike most existing capture zone studies,which are represented by initial relative velocity,the proposed capture zone investigates the initial velocity heading angle and side-window angle.First,the asymptotic fast convergence anti-interference guidance law is presented via motion camouflage theory,and it meets the Field of View(FOV)constraint by theoretical analysis.On this basis,the capture zone is derived with overload limits based on the Lyapunov-based function.Then,it is converted to the form defined by the velocity heading and side-window angles,considering the FOV constraint.Finally,the sensitivity of the capture zone to the designed guidance algorithm’s different influencing factors and the gain boundary are deduced and analyzed to provide a theoretical basis for augmenting the analytical capture zone during a practical engagement.The findings reveal the capture zone correlation mechanism of terminal guidance law and give academic support to the subsequent acquisition of arbitrary maneuvering targets,which has potential application value.展开更多
Based upon motion capture,a semi-automatic technique for fast facial animation was implemented. While capturing the facial expressions from a performer,a camera was used to record her /his front face as a texture map....Based upon motion capture,a semi-automatic technique for fast facial animation was implemented. While capturing the facial expressions from a performer,a camera was used to record her /his front face as a texture map. The radial basis function( RBF) technique was utilized to deform a generic facial model and the texture was remapped to generate a personalized face.Partitioning the personalized face into three regions and using the captured facial expression data,the RBF and Laplacian operator,and mean-value coordinates were implemented to deform each region respectively. With shape blending,the three regions were combined together to construct the final face model. Our results show that the technique is efficient in generating realistic facial animation.展开更多
This paper presented a novel tinny motion capture system for measuring bird posture based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. Mul...This paper presented a novel tinny motion capture system for measuring bird posture based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. Multiple quaternion-based extended Kalman filters were implemented to estimate the absolute orientations to achieve high accuracy.Under the guidance of ornithology experts, the extending/contracting motions and flapping cycles were recorded using the developed motion capture system, and the orientation of each bone was also analyzed. The captured flapping gesture of the Falco peregrinus is crucial to the motion database of raptors as well as the bionic design.展开更多
This study presents a kinematic calibration method for exoskeletal inertial motion capture (EI-MoCap) system with considering the random colored noise such as gyroscopic drift.In this method, the geometric parameters ...This study presents a kinematic calibration method for exoskeletal inertial motion capture (EI-MoCap) system with considering the random colored noise such as gyroscopic drift.In this method, the geometric parameters are calibrated by the traditional calibration method at first. Then, in order to calibrate the parameters affected by the random colored noise, the expectation maximization (EM) algorithm is introduced. Through the use of geometric parameters calibrated by the traditional calibration method, the iterations under the EM framework are decreased and the efficiency of the proposed method on embedded system is improved. The performance of the proposed kinematic calibration method is compared to the traditional calibration method. Furthermore, the feasibility of the proposed method is verified on the EI-MoCap system. The simulation and experiment demonstrate that the motion capture precision is significantly improved by 16.79%and 7.16%respectively in comparison to the traditional calibration method.展开更多
The paper aims to execute puppet without restrictions by controling puppet using robot. We controling puppet in the same way as the present puppet, but we perform this by robot. It offers more advantages and lessen th...The paper aims to execute puppet without restrictions by controling puppet using robot. We controling puppet in the same way as the present puppet, but we perform this by robot. It offers more advantages and lessen the weak points. It needs various actions and expressions because of the nature of a puppet. The biggest problem which executes this is the ways to create a system. This thesis proposes motion capture of developed method with solution of this problem. So, we create various contents needed by puppet. In this part, developed method means a mixed method on the basis of optical system and magnetic system used mainly for the present method of motion capture. We lessen the weak points of each method and propoe solution of create motion for pupct by offering more advantages. So we solve difficulties of executing puppet and probable probkans when we execute puppet by using robot. The solution of this thesis is proven by applying control of puppet.展开更多
Optical motion capture is an increasingly popular animation technique. In the last few years, plenty of methods have been proposed for key-frame extraction of motion capture data, and it is a common method to extract ...Optical motion capture is an increasingly popular animation technique. In the last few years, plenty of methods have been proposed for key-frame extraction of motion capture data, and it is a common method to extract key-frame using quaternion. Here, one main difficulty is due to the fact that previous algorithms often need to manually set various parameters. In addition, it is problematic to predefine the appropriate threshold without knowing the data content. In this paper, we present a novel adaptive threshold-based extraction method. Key-frame can be found according to quaternion distance. We propose a simple and efficient algorithm to extract key-frame from a motion sequence based on adaptive threshold. It is convenient with no need to predefine parameters to meet certain compression ratio. Experimental results of many motion captures with different traits demonstrate good performance of the proposed algorithm. Our experiments show that one can typically cut down the process of extraction from several minutes to a couple of seconds.展开更多
Silk Road dance is an excellent traditional Chinese dance drama, which has high artistic values. This article introduces the virtual performance techniques of Silk Road based on motion capture. First, obtain the dance...Silk Road dance is an excellent traditional Chinese dance drama, which has high artistic values. This article introduces the virtual performance techniques of Silk Road based on motion capture. First, obtain the dance data using motion capture technique according to the features of dance itself, then establish figure model, finally combines these data to make 3-D animation system to perform Silk Road, meanwhile designs some interfaces to introduce it. This system excavates details of the dance, and can be reference of man-machine interaction and animation production.展开更多
The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In...The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In this paper, an optical motion capture system based on the virtual reality technology is proposed to meet the requirements of the power enterprise for the qualified business ability. Electric power equipment, power equipment model entitative operating environment and the human model are established by electric power simulation unit, ZigBee technology and OpenGL graphics library. The problem of missing feature points is solved by applying the human model driven algorithm and the Kalman filtering algorithm. The experimental results show that it is more accurate to use Kalman filtering algorithm to extract the feature point in tracking process of actual motion capture and real-time animation display. The average absolute error of 3D coordinates is 1.61 mm and the average relative error is 2.23%. The system can improve trainees’ sense of experience and immersion.展开更多
Biomechanics is the study of physiological properties of data and the measurement of human behavior.In normal conditions,behavioural properties in stable form are created using various inputs of subconscious/conscious...Biomechanics is the study of physiological properties of data and the measurement of human behavior.In normal conditions,behavioural properties in stable form are created using various inputs of subconscious/conscious human activities such as speech style,body movements in walking patterns,writing style and voice tunes.One cannot perform any change in these inputs that make results reliable and increase the accuracy.The aim of our study is to perform a comparative analysis between the marker-based motion capturing system(MBMCS)and the marker-less motion capturing system(MLMCS)using the lower body joint angles of human gait patterns.In both the MLMCS and MBMCS,we collected trajectories of all the participants and performed joint angle computation to identify a person and recognize an activity(walk and running).Using five state of the art machine learning algorithms,we obtained 44.6%and 64.3%accuracy in person identification using MBMCS and MLMCS respectively with an ensemble algorithm(two angles as features).In the second set of experiments,we used six machine learning algorithms to obtain 65.9%accuracy with the k-nearest neighbor(KNN)algorithm(two angles as features)and 74.6%accuracy with an ensemble algorithm.Also,by increasing features(6 angles),we obtained higher accuracy of 99.3%in MBMCS for person recognition and 98.1%accuracy in MBMCS for activity recognition using the KNN algorithm.MBMCS is computationally expensive and if we redesign the model of OpenPose with more body joint points and employ more features,MLMCS(low-cost system)can be an effective approach for video data analysis in a person identification and activity recognition process.展开更多
Background:The development of computer vision technology has enabled the use of markerless movement tracking for biomechanical analysis.Recent research has reported the feasibility of markerless systems in motion anal...Background:The development of computer vision technology has enabled the use of markerless movement tracking for biomechanical analysis.Recent research has reported the feasibility of markerless systems in motion analysis but has yet to fully explore their utility for capturing faster movements,such as running.Applied studies using markerless systems in clinical and sports settings are still lacking.Thus,the present study compared running biomechanics estimated by marker-based and markerless systems.Given running speed not only affects sports performance but is also associated with clinical injury prevention,diagnosis,and rehabilitation,we aimed to investigate the effects of speed on the comparison of estimated lower extremity joint moments and powers between markerless and marker-based technologies during treadmill running as a concurrent validating study.Methods:Kinematic data from marker-based/markerless technologies were collected,along with ground reaction force data,from 16 young adults running on an instrumented treadmill at 3 speeds:2.24 m/s,2.91 m/s,and 3.58 m/s(5.0 miles/h,6.5 miles/h,and 8.0 miles/h).Sagittal plane moments and powers of the hip,knee,and ankle were calculated by inverse dynamic methods.Time series analysis and statistical parametric mapping were used to determine system differences.Results:Compared to the marker-based system,the markerless system estimated increased lower extremity joint kinetics with faster speed during the swing phase in most cases.Conclusion:Despite the promising application of markerless technology in clinical settings,systematic markerless overestimation requires focused attention.Based on segment pose estimations,the centers of mass estimated by markerless technologies were farther away from the relevant distal joint centers,which led to greater joint moments and powers estimates by markerless vs.marker-based systems.The differences were amplified by running speed.展开更多
Compactly supported radial basis function can enable the coefficient matrix of solving weigh linear system to have a sparse banded structure, thereby reducing the complexity of the algorithm. Firstly, based on the com...Compactly supported radial basis function can enable the coefficient matrix of solving weigh linear system to have a sparse banded structure, thereby reducing the complexity of the algorithm. Firstly, based on the compactly supported radial basis function, the paper makes the complex quadratic function （Multiquadric, MQ for short） to be transformed and proposes a class of compactly supported MQ function. Secondly, the paper describes a method that interpolates discrete motion capture data to solve the motion vectors of the interpolation points and they are used in facial expression reconstruction. Finally, according to this characteris- tic of the uneven distribution of the face markers, the markers are numbered and grouped in accordance with the density level, and then be interpolated in line with each group. The approach not only ensures the accuracy of the deformation of face local area and smoothness, but also reduces the time complexity of computing.展开更多
This paper proposes a human body motion capturing system using the depth images. It consists of three processes to estimate the human pose parameters. First, we develop a pixel-based body part classifier to segment th...This paper proposes a human body motion capturing system using the depth images. It consists of three processes to estimate the human pose parameters. First, we develop a pixel-based body part classifier to segment the human silhouette into different body part sub-regions and extract the primary joints. Second, we convert the distribution of the joints to the feature vector and apply the regression forest to estimate human pose parameters. Third, we apply the temporal constraints mechanism to find the best human pose parameter with the minimum estimation error. In experiments, we show that our system can operate in real-time with sufficient accuracy.展开更多
基金Supported by Jiangsu Provincial Natural Science Foundation(Grant No.BK20220649)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.23KJB460010)+2 种基金Provincial Key Laboratory of High-end Deepsea Machinery Equipment(Grant Nos.SYH2024003 and SYH2025001)the Jiangsu Provincial Key R&D Project(Grant No.BE2022062)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.SJCX25_2526).
文摘The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle(AUV)retrieval and release.This study aims to develop a capture mechanism for the launch and recovery of AUV and elucidate its kinematic characteristics.Initially,based on the principles of deployment and retraction for AUV capture movements,a design scheme for a novel foldable and deployable capture mechanism is proposed.Subsequently,a detailed analysis of the Degrees of Freedom(DoFs)for enveloping and grasping movements is conducted according to screw theory.Additionally,the structural design of the actuation units for the capture mechanism is thoroughly discussed.Motion screw topology diagram is utilized to construct the kinematic model.On this basis,kinematic simulation verification of the capture mechanism is performed.The theoretical analysis revealed that the DoF for enveloping and grasping movements are 6 and 2,respectively.By appropriately configuring the actuation mechanism,enveloping and grasping movements can be achieved with a single actuation.The displacement and velocity curves of the capture mechanism were smooth,with no interference occurring.Vibration test results validate the reliability of the capture mechanism.The research work provides a valuable reference for the development of novel capture equipment for AUVs.
基金funded by the National Natural Science Foundation of China (Grant Nos. 31601870 and 51435008)Natural Science Foundation of Jiangsu Province, China (Grant No. SBK20160800 to Zhouyi WANG)Jiangsu Provincial Key Laboratory of Bionic Functional Materials
文摘Animals have evolved a variety of behavior patterns to adapt to the environment. Motion-capture technology is utilized to quantify and characterize locomotor behaviors to reveal the mechanisms of animal motion. In the capture of flexible, small animals with complex locomotor behaviors, the markers interfere with each other easily, and the motion forms(bending, twisting) of the moving parts are obviously different;thus, it is a great challenge to realize accurate quantitative characterization of complex locomotor behaviors. The correlation between the marker properties, including the size and space length, and the precision of the system are revealed in this paper, and the effects of diverse marker shapes on the capturing accuracy of the captured objects in different motion forms were tested. Results showed that the precision of system is significantly improved when the ratio of the space length to the diameter of the markers is larger than four;for the capture of the spatial twisting motion of the flexible object, the hexagon markers had the lowest spatial lost-marker rate relative to the circle, triangle, and square. Customized markers were used to capture the locomotor behavior of the gecko-inspired robot(rigid connection) and the gecko(flexible connection). The results showed that this marking technology can achieve high accuracy of motion capture for geckos(the average deviation was approximately 0.32 mm, and the average deviation’s variation rate was approximately 0.96%). In this paper, the marking technology for the motion capture of flexible, small animals with complex motion is proposed;it can effectively improve the system precision as well as the capture accuracy, and realize the quantitative characterization of the complex motion of flexible, small objects. It provides a reliable technical means to deeply study the evolution of the motion function of small animals and advance systematic research of motion-capture technology.
基金Supported by the National Natural Science Foundation of China(No.60875046)by Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1109)+5 种基金the Key Project of Chinese Ministry of Education(No.209029)the Program for Liaoning Excellent Talents in University(No.LR201003)the Program for Liaoning Science and Technology Research in University(No.LS2010008,2009S008,2009S009,LS2010179)the Program for Liaoning Innovative Research Team in University(Nos.2009T005,LT2010005,LT2011018)Natural Science Foundation of Liaoning Province(201102008)by"Liaoning BaiQianWan Talents Program(2010921010,2011921009)"
文摘In order to high reality and efficiency, the technique computer animation. With the development of motion capture, a of motion capture （MoCap） has been widely used in the field of large amount of motion capture databases are available and this is significant for the reuse of motion data. But due to the high degree of freedoms and high capture frequency, the dimension of the mo- tion capture data is usually very high and this will lead to a low efficiency in data processing. So how to process the high dimension data and design an efficient and effective retrieval approach has become a challenge which we can＇t ignore. In this paper, first we lay out some problems about the key techniques in motion capture data processing. Then the existing approaches are analyzed and sum- marized. At last, some future work is proposed.
基金supported by the National Natural Science Foundation of China(Nos.62403171,T2388101)。
文摘Accurate motion prediction of free-tumbling satellites is crucial for the success of capture operations.This paper proposes a two-step method to estimate the motion states and parameters of such satellites,thereby enabling precise long-term motion prediction.This paper begins with a measurement of the system's degree of observability,quantified through the Empirical Observability Gramian(EOG).Based on this measurement,a batch processing algorithm is first employed to estimate the satellite's constant parameters offline.Subsequently,an online filtering algorithm,utilizing a minimal state set,fine-tunes these parameters and estimates the motion states in real time.This integrated approach significantly enhances both convergence properties and estimation accuracy,particularly for systems with poor observability.Utilizing the predicted long-term motion of the satellite,a composite evaluation metric is formulated to identify the optimal capture point and moment.The base pose of the space robot is then adjusted to ensure that the optimal capture point lies within the manipulator's dexterous workspace,which is determined through a pre-constructed capability map.The effectiveness of the proposed method is demonstrated through both simulation and experimental results.
文摘Concerning the capture problem against arbitrary maneuvering targets,whose overload is high maneuvering but upper bounded and velocity has advantages,this paper elucidates a three-dimensional multi-constraint analytical capture zone,exhibiting prominent guiding significance to the initial states of the terminal guidance.Unlike most existing capture zone studies,which are represented by initial relative velocity,the proposed capture zone investigates the initial velocity heading angle and side-window angle.First,the asymptotic fast convergence anti-interference guidance law is presented via motion camouflage theory,and it meets the Field of View(FOV)constraint by theoretical analysis.On this basis,the capture zone is derived with overload limits based on the Lyapunov-based function.Then,it is converted to the form defined by the velocity heading and side-window angles,considering the FOV constraint.Finally,the sensitivity of the capture zone to the designed guidance algorithm’s different influencing factors and the gain boundary are deduced and analyzed to provide a theoretical basis for augmenting the analytical capture zone during a practical engagement.The findings reveal the capture zone correlation mechanism of terminal guidance law and give academic support to the subsequent acquisition of arbitrary maneuvering targets,which has potential application value.
基金Youth Foundation of Higher Education Scientific Research of Hebei Province,China(No.2010228)Foundation for Returned Overseas Scholars of Hebei Province,China(No.C2013003015)
文摘Based upon motion capture,a semi-automatic technique for fast facial animation was implemented. While capturing the facial expressions from a performer,a camera was used to record her /his front face as a texture map. The radial basis function( RBF) technique was utilized to deform a generic facial model and the texture was remapped to generate a personalized face.Partitioning the personalized face into three regions and using the captured facial expression data,the RBF and Laplacian operator,and mean-value coordinates were implemented to deform each region respectively. With shape blending,the three regions were combined together to construct the final face model. Our results show that the technique is efficient in generating realistic facial animation.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.52175279 and 51705459)the Natural Science Foundation of Zhejiang Province,China (Grant No.LY20E050022)the Key Research and Development Projects of Zhejiang Provincial Science and Technology Department (Grant No.2021C03122)。
文摘This paper presented a novel tinny motion capture system for measuring bird posture based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. Multiple quaternion-based extended Kalman filters were implemented to estimate the absolute orientations to achieve high accuracy.Under the guidance of ornithology experts, the extending/contracting motions and flapping cycles were recorded using the developed motion capture system, and the orientation of each bone was also analyzed. The captured flapping gesture of the Falco peregrinus is crucial to the motion database of raptors as well as the bionic design.
基金supported by the National Natural Science Foundation of China (61503392)。
文摘This study presents a kinematic calibration method for exoskeletal inertial motion capture (EI-MoCap) system with considering the random colored noise such as gyroscopic drift.In this method, the geometric parameters are calibrated by the traditional calibration method at first. Then, in order to calibrate the parameters affected by the random colored noise, the expectation maximization (EM) algorithm is introduced. Through the use of geometric parameters calibrated by the traditional calibration method, the iterations under the EM framework are decreased and the efficiency of the proposed method on embedded system is improved. The performance of the proposed kinematic calibration method is compared to the traditional calibration method. Furthermore, the feasibility of the proposed method is verified on the EI-MoCap system. The simulation and experiment demonstrate that the motion capture precision is significantly improved by 16.79%and 7.16%respectively in comparison to the traditional calibration method.
基金supported bythe Ministry of Knowledge Economy,Korea,the ITRC(Information Technology Research Center)support program(No.NIPA-2009-(C1090-0902-0007))
文摘The paper aims to execute puppet without restrictions by controling puppet using robot. We controling puppet in the same way as the present puppet, but we perform this by robot. It offers more advantages and lessen the weak points. It needs various actions and expressions because of the nature of a puppet. The biggest problem which executes this is the ways to create a system. This thesis proposes motion capture of developed method with solution of this problem. So, we create various contents needed by puppet. In this part, developed method means a mixed method on the basis of optical system and magnetic system used mainly for the present method of motion capture. We lessen the weak points of each method and propoe solution of create motion for pupct by offering more advantages. So we solve difficulties of executing puppet and probable probkans when we execute puppet by using robot. The solution of this thesis is proven by applying control of puppet.
基金Supported by National Natural Science Foundation of China(No.60875046)Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1109)+5 种基金Key Project of Chinese Ministry of Education(No.209029)Program for Liaoning Excellent Talents in University(No.LR201003)Program for Liaoning Science and Technology Research in University(Nos.LS2010008,2009S008,2009S009,LS2010179)Program for Liaoning Innovative Research Team in University(Nos.2009T005,LT2010005,LT2011018)Natural Science Foundation of Liaoning Province(No.201102008)"Liaoning BaiQianWan Talents Program(Nos.2010921010,2011921009)"
文摘Optical motion capture is an increasingly popular animation technique. In the last few years, plenty of methods have been proposed for key-frame extraction of motion capture data, and it is a common method to extract key-frame using quaternion. Here, one main difficulty is due to the fact that previous algorithms often need to manually set various parameters. In addition, it is problematic to predefine the appropriate threshold without knowing the data content. In this paper, we present a novel adaptive threshold-based extraction method. Key-frame can be found according to quaternion distance. We propose a simple and efficient algorithm to extract key-frame from a motion sequence based on adaptive threshold. It is convenient with no need to predefine parameters to meet certain compression ratio. Experimental results of many motion captures with different traits demonstrate good performance of the proposed algorithm. Our experiments show that one can typically cut down the process of extraction from several minutes to a couple of seconds.
基金Co-supported by Gansu Science and Technology Major Project(1302FKDA036)Natural Science Fund Project in Xinjiang(2014211A046)
文摘Silk Road dance is an excellent traditional Chinese dance drama, which has high artistic values. This article introduces the virtual performance techniques of Silk Road based on motion capture. First, obtain the dance data using motion capture technique according to the features of dance itself, then establish figure model, finally combines these data to make 3-D animation system to perform Silk Road, meanwhile designs some interfaces to introduce it. This system excavates details of the dance, and can be reference of man-machine interaction and animation production.
文摘The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In this paper, an optical motion capture system based on the virtual reality technology is proposed to meet the requirements of the power enterprise for the qualified business ability. Electric power equipment, power equipment model entitative operating environment and the human model are established by electric power simulation unit, ZigBee technology and OpenGL graphics library. The problem of missing feature points is solved by applying the human model driven algorithm and the Kalman filtering algorithm. The experimental results show that it is more accurate to use Kalman filtering algorithm to extract the feature point in tracking process of actual motion capture and real-time animation display. The average absolute error of 3D coordinates is 1.61 mm and the average relative error is 2.23%. The system can improve trainees’ sense of experience and immersion.
基金Data and Artificial Intelligence Scientific Chair at Umm Al-Qura University.
文摘Biomechanics is the study of physiological properties of data and the measurement of human behavior.In normal conditions,behavioural properties in stable form are created using various inputs of subconscious/conscious human activities such as speech style,body movements in walking patterns,writing style and voice tunes.One cannot perform any change in these inputs that make results reliable and increase the accuracy.The aim of our study is to perform a comparative analysis between the marker-based motion capturing system(MBMCS)and the marker-less motion capturing system(MLMCS)using the lower body joint angles of human gait patterns.In both the MLMCS and MBMCS,we collected trajectories of all the participants and performed joint angle computation to identify a person and recognize an activity(walk and running).Using five state of the art machine learning algorithms,we obtained 44.6%and 64.3%accuracy in person identification using MBMCS and MLMCS respectively with an ensemble algorithm(two angles as features).In the second set of experiments,we used six machine learning algorithms to obtain 65.9%accuracy with the k-nearest neighbor(KNN)algorithm(two angles as features)and 74.6%accuracy with an ensemble algorithm.Also,by increasing features(6 angles),we obtained higher accuracy of 99.3%in MBMCS for person recognition and 98.1%accuracy in MBMCS for activity recognition using the KNN algorithm.MBMCS is computationally expensive and if we redesign the model of OpenPose with more body joint points and employ more features,MLMCS(low-cost system)can be an effective approach for video data analysis in a person identification and activity recognition process.
文摘Background:The development of computer vision technology has enabled the use of markerless movement tracking for biomechanical analysis.Recent research has reported the feasibility of markerless systems in motion analysis but has yet to fully explore their utility for capturing faster movements,such as running.Applied studies using markerless systems in clinical and sports settings are still lacking.Thus,the present study compared running biomechanics estimated by marker-based and markerless systems.Given running speed not only affects sports performance but is also associated with clinical injury prevention,diagnosis,and rehabilitation,we aimed to investigate the effects of speed on the comparison of estimated lower extremity joint moments and powers between markerless and marker-based technologies during treadmill running as a concurrent validating study.Methods:Kinematic data from marker-based/markerless technologies were collected,along with ground reaction force data,from 16 young adults running on an instrumented treadmill at 3 speeds:2.24 m/s,2.91 m/s,and 3.58 m/s(5.0 miles/h,6.5 miles/h,and 8.0 miles/h).Sagittal plane moments and powers of the hip,knee,and ankle were calculated by inverse dynamic methods.Time series analysis and statistical parametric mapping were used to determine system differences.Results:Compared to the marker-based system,the markerless system estimated increased lower extremity joint kinetics with faster speed during the swing phase in most cases.Conclusion:Despite the promising application of markerless technology in clinical settings,systematic markerless overestimation requires focused attention.Based on segment pose estimations,the centers of mass estimated by markerless technologies were farther away from the relevant distal joint centers,which led to greater joint moments and powers estimates by markerless vs.marker-based systems.The differences were amplified by running speed.
基金Supported by the National Natural Science Foundation of China (No.60875046)by Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1109)+5 种基金the Key Project of Chinese Ministry of Education (No.209029)the Program for Liaoning Excellent Talents in University(No.LR201003)the Program for Liaoning Science and Technology Research in University (No.LS2010008,2009S008,2009S009,LS2010179)the Program for Liaoning Innovative Research Team in University(Nos.2009T005,LT2010005,LT2011018)Natural Science Foundation of Liaoning Province (201102008)by "Liaoning BaiQianWan Talents Program(2010921010,2011921009)"
文摘Compactly supported radial basis function can enable the coefficient matrix of solving weigh linear system to have a sparse banded structure, thereby reducing the complexity of the algorithm. Firstly, based on the compactly supported radial basis function, the paper makes the complex quadratic function （Multiquadric, MQ for short） to be transformed and proposes a class of compactly supported MQ function. Secondly, the paper describes a method that interpolates discrete motion capture data to solve the motion vectors of the interpolation points and they are used in facial expression reconstruction. Finally, according to this characteris- tic of the uneven distribution of the face markers, the markers are numbered and grouped in accordance with the density level, and then be interpolated in line with each group. The approach not only ensures the accuracy of the deformation of face local area and smoothness, but also reduces the time complexity of computing.
基金supported by“MOST”under Grant No.103-2221-E-468-006-MY2
文摘This paper proposes a human body motion capturing system using the depth images. It consists of three processes to estimate the human pose parameters. First, we develop a pixel-based body part classifier to segment the human silhouette into different body part sub-regions and extract the primary joints. Second, we convert the distribution of the joints to the feature vector and apply the regression forest to estimate human pose parameters. Third, we apply the temporal constraints mechanism to find the best human pose parameter with the minimum estimation error. In experiments, we show that our system can operate in real-time with sufficient accuracy.
