The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform

Tomas Martinec - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of industrial robot trajectory in frame composite production
    Programs and Algorithms of Numerical Mathematics 18, 2017
    Co-Authors: Jaroslav Mlýnek, Tomas Martinec, Michal Petrů
    Abstract:

    This article is focused on calculating the trajectory of an industrial robot in the production of composites for the automotive industry. The production technology is based on the winding of carbon fibres on a polyurethane frame. The frame is fastened to the end-effector of the robot arm (i.e. robot-end-effector, REE). The passage of the frame through the fibre processing head is determined by the REE trajectory. The position of the fibre processing head is fixed and is composed of three fibre guide wheels with coils of carbon fibres. The fibre processing head winds three layers of filaments onto the frame. The polyurethane frame is determined by the local Euclidean Coordinate system $E_{3}$, which has its origin in the REE. We use a mathematical model and matrix calculus to compute the trajectory of the REE to guarantee the desired passage of the frame through the fibre processing head. The translation and rotation matrices of the local Coordinate system (of the REE) are calculated with respect to the base Coordinate system of the robot.

  • Composite Production and Industrial Robot Trajectory Calculation
    Advances in Mechanism Design II, 2016
    Co-Authors: Tomas Martinec, Jaroslav Mlýnek, Michal Petrů
    Abstract:

    This paper discusses the problem of composite production. Composites often supplant traditional materials such as steel, iron, wood, etc. The most important advantages of composites are their high strength and flexibility, low weight, long lifespan and minimum maintenance. The technology used in this article is based on a winding of a carbon (or a glass) filament rovings on a polyurethane core which is a frame shape in 3D space with a circular cross section. The polyurethane frame is fastened to the robot-end-effector of the robot arm and during the winding process goes through a fiber-processing head on the basis of the suitably determined robot-end-effector trajectory. The fiber-processing head is fixed in robot working space and is composed of three guide lines with coils of carbon rovings. Quality production of described type of composite depends primarily on the correct winding of fibers on a polyurethane frame. It is especially needed to ensure the correct angles of the fibers winding on a polyurethane frame and the homogeneity of individual winding layers. The polyurethane frame is specified in the local Euclidean Coordinate system E3, the origin of this system is in the robot-end-effector. We use the matrix calculus to enumerate the trajectory of the robot-end-effector to determine the desired passage of the frame through the fiber-processing head. A practical example of the passage of a polyurethane frame through fiber-processing head is dealt with in the article. Of course, the determining calculation of the robot trajectory can be used in other applications of industrial robot use.

  • Calculation of the robot trajectory for the optimum directional orientation of fibre placement in the manufacture of composite profile frames
    Robotics and Computer-integrated Manufacturing, 2015
    Co-Authors: Tomas Martinec, Jaroslav Mlýnek, Michal Petru
    Abstract:

    This article deals with theissue of calculating the trajectory of the end-effector of an industrial robot in the manufacture of composites. In the introduction to the article we describe the basic approaches used in the manufacture of composites. Robots are used to define the winding orientation of carbon fibre strands on an uneven polyurethane 3D core. The core is attached to the robot-end-effector and is led through a fibre-processing head according to a suitably defined robot trajectory during dry carbon fibre winding on the core. The model of a passage of the polyurethane core through a fibre-processing head is described in the article. The placement of the fibre-processing head is defined in the basic Euclidean Coordinate system E3 of the robot. The core is specified in the local Coordinates of the Euclidean Coordinate system E3, the origin of this local system is in the robot-end-effector. The positioning of the local system in the basic system of the robot is entered using the "tool centre point" of the robot. A matrix calculus is used when calculating the trajectory robot-end-effector to determine the desired passage of the core through the fibre-processing head. Gradually, the required rotation and translation matrices of the local Coordinate system of the robot-end-effector relative to the basic system are calculated and subsequently the Euler angles of rotation are determined corresponding to the transformation matrices. This is used to determine the sequence of values of the "tool centre point" for defining the desired trajectory of the robot-end-effector. The calculation for the trajectory was programmed in the Delphi development environment. The article also solves practical tasks of the polyurethane core passage through the fibre-processing head. The calculations of the trajectory of the robot-end-effector were used as input values for the graphic software simulator and at the same time winding of carbon strands on the polyurethane core was verified for the calculated trajectory of the robot-end-effector in the experimental laboratory. The described algorithm allows us to calculate and determine the accurate 3D trajectory of the end-effector of an industrial robot during the manufacture of composite profiles using a dry fibre winding technology on a polyurethane core with a circular cross-section.The algorithm can be applied to any manufacturing process where it is necessary to determine the 3D trajectory of a robot end-effector.Suppliers of industrial robots currently offer specific software tools facilitating control of the robot end-effector when programming specific tasks (machining, welding, cutting, grinding or painting) but none of them are suitable for use for the described task.In engineering and manufacturing practice, there are specific activities that require the determination of an industrial robot trajectory but it often occurs that a suitable commercial software product does not exist or is not available for the technician.The algorithm allows us to determine the exact trajectory of the robot end-effector, which provides a significant advantage over manually entered robot trajectory. It requires practical experience of technician and this technique is time-consuming.Use of the described algorithm is completely independent of the type of production robot and software tools.Possibility to accurately determine the desired trajectory of the robot end-effector using the algorithm can be beneficial for optimizing the robot trajectory in the production cycle.The procedure for determining the trajectory of the robot end-effector is at virtually no additional cost to the manufacturer and can significantly speed up the determination of the desired trajectory of the end-effector.The described algorithm in article can be successfully utilized by the technicians of manufacturing robotic workplaces and also by developers of specific software tools for controlling of manufacture robots.

  • Mathematical model of composite manufacture and calculation of robot trajectory
    Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014, 2014
    Co-Authors: Jaroslav Mlýnek, Tomas Martinec
    Abstract:

    This paper discusses the problem of calculating the trajectory in a 3D environment of an industrial robot in the production of composites for the automotive industry. The used technology is based on a winding of a carbon (or a glass) filament rovings on a non-bearing polyurethane core which is a frame shape with a circular cross section. The polyurethane frame is fastened to the end-effector of the robot arm (robot-end-effector) and during the winding process goes through a fibre-processing head on the basis of the suitably determined robot-end-effector trajectory. The fibre-processing head is fixed and is composed of three guide lines (two outer lines are rotary and the middle is static) with coils of carbon rovings. The fibre-processing head winds on the frame three layers of filaments at angles of 45°, 0° and −45°. The model of a non-bearing polyurethane frame passing through the fibre-processing head is described in Euclidean space E 3 of the robot. The non-bearing polyurethane frame is specified in the local Euclidean Coordinate system E 3 , the origin of this system is in the robot-end-effector. The location of the local system of the robot-end-effector in the basic Coordinate system of the robot is specified using the “tool-center-point” of the robot. We use the described mathematical model and matrix calculus to calculate the trajectory of the robot-end-effector to determine the desired passage of the frame through the fibre-processing head. The required translation and rotation matrices of the local Coordinate system (of the robot-end-effector) relative to the base Coordinate system of the robot are gradually calculated. Subsequently, the Euler angles of rotations are determined corresponding to the transformation matrices. The sequence of “tool-center-point” values which allows us to define the desired trajectory of the robot-end-effector and thereby the passage of the frame through the fibre-processing head is determined in this manner. The calculation of the trajectory was programmed in the Delphi development environment. A practical example of the passage of a polyurethane non-bearing frame through fibre-processing head is dealt with in the article. The calculation of the robot-end-effector trajectory was used as input values for a graphics software simulator of robot activities. We can accurately determine the trajectory of the robot-end-effector during required work activities of the robot. This approach of determining the exact trajectory is qualitatively different from the application of the principle of programming a robot by teach-in. The advantages of the described approach will be significantly enforced, for example, when we need to solve the problem of the robot-end-effector trajectory optimization. The determining calculation of the trajectory can of course be used in other applications of industrial robot use. Moreover, the described procedure for determining the trajectory brings the manufacturer almost no additional costs.

Jung-shyr Wu - One of the best experts on this subject based on the ideXlab platform.

  • A System with Hidden Markov Models and Gaussian Mixture Models for 3D Handwriting Recognition on Handheld Devices Using Accelerometers
    Behavior Computing, 2012
    Co-Authors: Yi-yuan Chiang, Jung-shyr Wu
    Abstract:

    Based on accelerometer, we propose a 3D handwriting recognition system in this paper. The system is consists of 4 main parts: (1) data collection: a single tri-axis accelerometer is mounted on a handheld device to collect different handwriting data. A set of key patterns have to be written using the handheld device several times for consequential processing and training. (2) Data preprocessing: time series are mapped into eight octant of three-dimensional Euclidean Coordinate system. (3) Data training: hidden Markov models (HMMs) and Gaussian mixture models (GMMs) are combined to perform the classification task. (4) Pattern recognition: using the trained HMM to carry out the prediction task. To evaluate the performance of our handwriting recognition model, we choose the experiment of recognizing a set of English words. The accuracy of classification could be achieved at about 96.5%.

  • Integrating weighted LCS and SVM for 3D handwriting recognition on handheld devices using accelerometers
    WSEAS Transactions on Computers archive, 2010
    Co-Authors: Yi-yuan Chiang, Jung-shyr Wu
    Abstract:

    Based on accelerometer, we propose a 3D handwriting recognition system in this paper. The system is consists of 4 main parts: (1) data collection: a single tri-axis accelerometer is mounted on a handheld device to collect different handwriting data. A set of key patterns have to be written using the handheld device several times for consequential processing and training. (2) data preprocessing: time series are mapped into eight octant of three-dimensional Euclidean Coordinate system. (3) data training: weighted LCS and SVM are combined to perform the classification task. (4) pattern recognition: using the trained SVM model to carry out the prediction task. To evaluate the performance of our handwriting recognition model, we choose the experiment of recognizing a set of English words. The accuracy of classification could be achieved at about 96.85%.

  • Integrating LCS and SVM for 3D handwriting recognition on handheld devices using accelerometers
    2009
    Co-Authors: Yi-yuan Chiang, Jung-shyr Wu
    Abstract:

    Based on accelerometer, we propose a 3D handwriting recognition system in this paper. The system is consists of 4 main parts: (1) data collection: a single tri-axis accelerometer is mounted on a handheld device to collect different handwriting data. A set of key patterns have to be written using the handheld device several times for consequential processing and training. (2) data preprocessing: time series are mapped into eight octant of three-dimensional Euclidean Coordinate system. (3) data training: LCS and SVM are combined to perform the classification task. (4) pattern recognition: using the trained SVM model to carry out the prediction task. To evaluate the performance of our handwriting recognition model, we choose the experiment of recognizing a set of English words. The accuracy of classification could be achieved at about 93%.

Jaroslav Mlýnek - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of industrial robot trajectory in frame composite production
    Programs and Algorithms of Numerical Mathematics 18, 2017
    Co-Authors: Jaroslav Mlýnek, Tomas Martinec, Michal Petrů
    Abstract:

    This article is focused on calculating the trajectory of an industrial robot in the production of composites for the automotive industry. The production technology is based on the winding of carbon fibres on a polyurethane frame. The frame is fastened to the end-effector of the robot arm (i.e. robot-end-effector, REE). The passage of the frame through the fibre processing head is determined by the REE trajectory. The position of the fibre processing head is fixed and is composed of three fibre guide wheels with coils of carbon fibres. The fibre processing head winds three layers of filaments onto the frame. The polyurethane frame is determined by the local Euclidean Coordinate system $E_{3}$, which has its origin in the REE. We use a mathematical model and matrix calculus to compute the trajectory of the REE to guarantee the desired passage of the frame through the fibre processing head. The translation and rotation matrices of the local Coordinate system (of the REE) are calculated with respect to the base Coordinate system of the robot.

  • Composite Production and Industrial Robot Trajectory Calculation
    Advances in Mechanism Design II, 2016
    Co-Authors: Tomas Martinec, Jaroslav Mlýnek, Michal Petrů
    Abstract:

    This paper discusses the problem of composite production. Composites often supplant traditional materials such as steel, iron, wood, etc. The most important advantages of composites are their high strength and flexibility, low weight, long lifespan and minimum maintenance. The technology used in this article is based on a winding of a carbon (or a glass) filament rovings on a polyurethane core which is a frame shape in 3D space with a circular cross section. The polyurethane frame is fastened to the robot-end-effector of the robot arm and during the winding process goes through a fiber-processing head on the basis of the suitably determined robot-end-effector trajectory. The fiber-processing head is fixed in robot working space and is composed of three guide lines with coils of carbon rovings. Quality production of described type of composite depends primarily on the correct winding of fibers on a polyurethane frame. It is especially needed to ensure the correct angles of the fibers winding on a polyurethane frame and the homogeneity of individual winding layers. The polyurethane frame is specified in the local Euclidean Coordinate system E3, the origin of this system is in the robot-end-effector. We use the matrix calculus to enumerate the trajectory of the robot-end-effector to determine the desired passage of the frame through the fiber-processing head. A practical example of the passage of a polyurethane frame through fiber-processing head is dealt with in the article. Of course, the determining calculation of the robot trajectory can be used in other applications of industrial robot use.

  • Calculation of the robot trajectory for the optimum directional orientation of fibre placement in the manufacture of composite profile frames
    Robotics and Computer-integrated Manufacturing, 2015
    Co-Authors: Tomas Martinec, Jaroslav Mlýnek, Michal Petru
    Abstract:

    This article deals with theissue of calculating the trajectory of the end-effector of an industrial robot in the manufacture of composites. In the introduction to the article we describe the basic approaches used in the manufacture of composites. Robots are used to define the winding orientation of carbon fibre strands on an uneven polyurethane 3D core. The core is attached to the robot-end-effector and is led through a fibre-processing head according to a suitably defined robot trajectory during dry carbon fibre winding on the core. The model of a passage of the polyurethane core through a fibre-processing head is described in the article. The placement of the fibre-processing head is defined in the basic Euclidean Coordinate system E3 of the robot. The core is specified in the local Coordinates of the Euclidean Coordinate system E3, the origin of this local system is in the robot-end-effector. The positioning of the local system in the basic system of the robot is entered using the "tool centre point" of the robot. A matrix calculus is used when calculating the trajectory robot-end-effector to determine the desired passage of the core through the fibre-processing head. Gradually, the required rotation and translation matrices of the local Coordinate system of the robot-end-effector relative to the basic system are calculated and subsequently the Euler angles of rotation are determined corresponding to the transformation matrices. This is used to determine the sequence of values of the "tool centre point" for defining the desired trajectory of the robot-end-effector. The calculation for the trajectory was programmed in the Delphi development environment. The article also solves practical tasks of the polyurethane core passage through the fibre-processing head. The calculations of the trajectory of the robot-end-effector were used as input values for the graphic software simulator and at the same time winding of carbon strands on the polyurethane core was verified for the calculated trajectory of the robot-end-effector in the experimental laboratory. The described algorithm allows us to calculate and determine the accurate 3D trajectory of the end-effector of an industrial robot during the manufacture of composite profiles using a dry fibre winding technology on a polyurethane core with a circular cross-section.The algorithm can be applied to any manufacturing process where it is necessary to determine the 3D trajectory of a robot end-effector.Suppliers of industrial robots currently offer specific software tools facilitating control of the robot end-effector when programming specific tasks (machining, welding, cutting, grinding or painting) but none of them are suitable for use for the described task.In engineering and manufacturing practice, there are specific activities that require the determination of an industrial robot trajectory but it often occurs that a suitable commercial software product does not exist or is not available for the technician.The algorithm allows us to determine the exact trajectory of the robot end-effector, which provides a significant advantage over manually entered robot trajectory. It requires practical experience of technician and this technique is time-consuming.Use of the described algorithm is completely independent of the type of production robot and software tools.Possibility to accurately determine the desired trajectory of the robot end-effector using the algorithm can be beneficial for optimizing the robot trajectory in the production cycle.The procedure for determining the trajectory of the robot end-effector is at virtually no additional cost to the manufacturer and can significantly speed up the determination of the desired trajectory of the end-effector.The described algorithm in article can be successfully utilized by the technicians of manufacturing robotic workplaces and also by developers of specific software tools for controlling of manufacture robots.

  • Mathematical model of composite manufacture and calculation of robot trajectory
    Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014, 2014
    Co-Authors: Jaroslav Mlýnek, Tomas Martinec
    Abstract:

    This paper discusses the problem of calculating the trajectory in a 3D environment of an industrial robot in the production of composites for the automotive industry. The used technology is based on a winding of a carbon (or a glass) filament rovings on a non-bearing polyurethane core which is a frame shape with a circular cross section. The polyurethane frame is fastened to the end-effector of the robot arm (robot-end-effector) and during the winding process goes through a fibre-processing head on the basis of the suitably determined robot-end-effector trajectory. The fibre-processing head is fixed and is composed of three guide lines (two outer lines are rotary and the middle is static) with coils of carbon rovings. The fibre-processing head winds on the frame three layers of filaments at angles of 45°, 0° and −45°. The model of a non-bearing polyurethane frame passing through the fibre-processing head is described in Euclidean space E 3 of the robot. The non-bearing polyurethane frame is specified in the local Euclidean Coordinate system E 3 , the origin of this system is in the robot-end-effector. The location of the local system of the robot-end-effector in the basic Coordinate system of the robot is specified using the “tool-center-point” of the robot. We use the described mathematical model and matrix calculus to calculate the trajectory of the robot-end-effector to determine the desired passage of the frame through the fibre-processing head. The required translation and rotation matrices of the local Coordinate system (of the robot-end-effector) relative to the base Coordinate system of the robot are gradually calculated. Subsequently, the Euler angles of rotations are determined corresponding to the transformation matrices. The sequence of “tool-center-point” values which allows us to define the desired trajectory of the robot-end-effector and thereby the passage of the frame through the fibre-processing head is determined in this manner. The calculation of the trajectory was programmed in the Delphi development environment. A practical example of the passage of a polyurethane non-bearing frame through fibre-processing head is dealt with in the article. The calculation of the robot-end-effector trajectory was used as input values for a graphics software simulator of robot activities. We can accurately determine the trajectory of the robot-end-effector during required work activities of the robot. This approach of determining the exact trajectory is qualitatively different from the application of the principle of programming a robot by teach-in. The advantages of the described approach will be significantly enforced, for example, when we need to solve the problem of the robot-end-effector trajectory optimization. The determining calculation of the trajectory can of course be used in other applications of industrial robot use. Moreover, the described procedure for determining the trajectory brings the manufacturer almost no additional costs.

Michal Petrů - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of industrial robot trajectory in frame composite production
    Programs and Algorithms of Numerical Mathematics 18, 2017
    Co-Authors: Jaroslav Mlýnek, Tomas Martinec, Michal Petrů
    Abstract:

    This article is focused on calculating the trajectory of an industrial robot in the production of composites for the automotive industry. The production technology is based on the winding of carbon fibres on a polyurethane frame. The frame is fastened to the end-effector of the robot arm (i.e. robot-end-effector, REE). The passage of the frame through the fibre processing head is determined by the REE trajectory. The position of the fibre processing head is fixed and is composed of three fibre guide wheels with coils of carbon fibres. The fibre processing head winds three layers of filaments onto the frame. The polyurethane frame is determined by the local Euclidean Coordinate system $E_{3}$, which has its origin in the REE. We use a mathematical model and matrix calculus to compute the trajectory of the REE to guarantee the desired passage of the frame through the fibre processing head. The translation and rotation matrices of the local Coordinate system (of the REE) are calculated with respect to the base Coordinate system of the robot.

  • Composite Production and Industrial Robot Trajectory Calculation
    Advances in Mechanism Design II, 2016
    Co-Authors: Tomas Martinec, Jaroslav Mlýnek, Michal Petrů
    Abstract:

    This paper discusses the problem of composite production. Composites often supplant traditional materials such as steel, iron, wood, etc. The most important advantages of composites are their high strength and flexibility, low weight, long lifespan and minimum maintenance. The technology used in this article is based on a winding of a carbon (or a glass) filament rovings on a polyurethane core which is a frame shape in 3D space with a circular cross section. The polyurethane frame is fastened to the robot-end-effector of the robot arm and during the winding process goes through a fiber-processing head on the basis of the suitably determined robot-end-effector trajectory. The fiber-processing head is fixed in robot working space and is composed of three guide lines with coils of carbon rovings. Quality production of described type of composite depends primarily on the correct winding of fibers on a polyurethane frame. It is especially needed to ensure the correct angles of the fibers winding on a polyurethane frame and the homogeneity of individual winding layers. The polyurethane frame is specified in the local Euclidean Coordinate system E3, the origin of this system is in the robot-end-effector. We use the matrix calculus to enumerate the trajectory of the robot-end-effector to determine the desired passage of the frame through the fiber-processing head. A practical example of the passage of a polyurethane frame through fiber-processing head is dealt with in the article. Of course, the determining calculation of the robot trajectory can be used in other applications of industrial robot use.

Saban Eren - One of the best experts on this subject based on the ideXlab platform.

  • Computational Cost Analysis of Elliptic Curve Arithmetic
    2006 International Conference on Hybrid Information Technology, 2020
    Co-Authors: S. Atay, Ahmet Koltuksuz, Huseyin Hisil, Saban Eren
    Abstract:

    2006 International Conference on Hybrid Information Technology, ICHIT 2006; Cheju Island; South Korea; 9 November 2006 through 11 November 2006Elliptic curves are proposed for the asymmetrical cryptography by Neal Koblitz and Victor Miller in 1986 separately. Elliptic curve cryptography (ECC) is utilized by hardware embedded solutions on mobile equipments and smart cards after 2000. Currently, software implementation of ECC faces the computational speed problem. One of the proposed solutions is to do the arithmetic operations on different Euclidean Coordinate systems. This paper concentrates on the research of this technique and delineates the performance results of the implementation of the aforementioned technique on the different cryptographic libraries such as CRYMPIX, GMP and MIRACL

  • Computational Cost Analysis of Elliptic Curve Arithmetic
    2006
    Co-Authors: S. Atay, Ahmet Koltuksuz, Huseyin Hisil, Saban Eren
    Abstract:

    Elliptic curves are proposed for the asymmetrical cryptography by Neal Koblitz and Victor Miller in 1986 separately. Elliptic curve cryptography (ECC) is utilized by hardware embedded solutions on mobile equipments and smart cards after 2000. Currently, software implementation of ECC faces the computational speed problem. One of the proposed solutions is to do the arithmetic operations on different Euclidean Coordinate systems. This paper concentrates on the research of this technique and delineates the performance results of the implementation of the aforementioned technique on the different cryptographic libraries such as CRYMPIX, GMP and MIRACL.