Gantry robots are mainly employed for applications requiring large workspace, with limited higher... more Gantry robots are mainly employed for applications requiring large workspace, with limited higher manipulability in one direction than the others. The Gantries offer very good mechanical stiffness and constant positioning accuracy, but low dexterity. Common gantries are CNC machines with three translational joints XYZ (3DOF) and usually with an attached wrist (+3DOF). The translational joints are used to move the tool in any position in the 3D workspace. The wrist is used to orient the tool by rotation about X, Y and Z axis. This standard kinematic structure (3T3R) produces a rectangular workspace. In this paper a full kinematic model for a 6DOF general CNC (gantry) machine is presented, along with the Jacobian matrix and singularity analysis. Using Denavit-Hartenberg convention, firstly, the general kinematic structure is presented, in order to assign frames at each link. The forward kinematic problem is solved using Maple 17 software. Differential kinematics describes the analytical relationship between the joint motion and the end-effector motion in terms of velocities, through the manipulator Jacobian matrix. The configuration at which the manipulator Jacobian matrix drops rank is called singular configuration. In this paper the Jacobian matrix is derived using the vector cross multiplication method. The singularity conditions are examined and validated. The fully reachable workspace is plotted with Matlab tools using specified joint limits. The presented solutions are expressed in parametric manner and can be used for analysis of the existing gantry type machine as well as a design tool for new machines.
The vibratory feeders with electromagnetic excitation called
electromagnetic vibratory feeders ... more The vibratory feeders with electromagnetic excitation called
electromagnetic vibratory feeders (EMVF) are commonly used for performing gravimetric flow of granular and particulate materials in processing industry. This drives offer easy and simple control the mass flow of conveying materials. In comparison with other drives (pneumatics,
inertial, centrifugal, etc...), these have a more simple construction and they are compact, robust and reliable in operation. The absence of wearing mechanical part, such as gears, cams belts, bearings, eccentrics, etc., makes EMVF, most economical equipment. Standard power electronic
output stages intended for control of the EMVF using SCR devices (thyristors and triacs). This implies phase angle control (PAC) and constant frequency of vibration. In this way control circuit must be synchronized to the mains supply frequency 50(60) Hz. PAC can only accomplish tuning amplitude of vibration, but not vibratory frequency.
Application of transistor (IGBT or MOSFET) switch mode power converters enables accomplishing the amplitude and (or) frequency control of EMVF. Their use implies the excitation of an EMVF independent of the mains supply frequency. In addition, the frequency control ensures
operation in the region of mechanical resonance. This operation is highly efficient, because large output displacement is provided by small input power. An optimal and efficient operation requires tracking of resonant
frequency. This paper presents possible solution of the amplitude-frequency control of EMVF and corresponding simulation and experimental results.
Gantry robots are mainly employed for applications requiring large workspace, with limited higher... more Gantry robots are mainly employed for applications requiring large workspace, with limited higher manipulability in one direction than the others. The Gantries offer very good mechanical stiffness and constant positioning accuracy, but low dexterity. Common gantries are CNC machines with three translational joints XYZ (3DOF) and usually with an attached wrist (+3DOF). The translational joints are used to move the tool in any position in the 3D workspace. The wrist is used to orient the tool by rotation about X, Y and Z axis. This standard kinematic structure (3T3R) produces a rectangular workspace. In this paper a full kinematic model for a 6DOF general CNC (gantry) machine is presented, along with the Jacobian matrix and singularity analysis. Using Denavit-Hartenberg convention, firstly, the general kinematic structure is presented, in order to assign frames at each link. The forward kinematic problem is solved using Maple 17 software. Differential kinematics describes the analytical relationship between the joint motion and the end-effector motion in terms of velocities, through the manipulator Jacobian matrix. The configuration at which the manipulator Jacobian matrix drops rank is called singular configuration. In this paper the Jacobian matrix is derived using the vector cross multiplication method. The singularity conditions are examined and validated. The fully reachable workspace is plotted with Matlab tools using specified joint limits. The presented solutions are expressed in parametric manner and can be used for analysis of the existing gantry type machine as well as a design tool for new machines.
The vibratory feeders with electromagnetic excitation called
electromagnetic vibratory feeders ... more The vibratory feeders with electromagnetic excitation called
electromagnetic vibratory feeders (EMVF) are commonly used for performing gravimetric flow of granular and particulate materials in processing industry. This drives offer easy and simple control the mass flow of conveying materials. In comparison with other drives (pneumatics,
inertial, centrifugal, etc...), these have a more simple construction and they are compact, robust and reliable in operation. The absence of wearing mechanical part, such as gears, cams belts, bearings, eccentrics, etc., makes EMVF, most economical equipment. Standard power electronic
output stages intended for control of the EMVF using SCR devices (thyristors and triacs). This implies phase angle control (PAC) and constant frequency of vibration. In this way control circuit must be synchronized to the mains supply frequency 50(60) Hz. PAC can only accomplish tuning amplitude of vibration, but not vibratory frequency.
Application of transistor (IGBT or MOSFET) switch mode power converters enables accomplishing the amplitude and (or) frequency control of EMVF. Their use implies the excitation of an EMVF independent of the mains supply frequency. In addition, the frequency control ensures
operation in the region of mechanical resonance. This operation is highly efficient, because large output displacement is provided by small input power. An optimal and efficient operation requires tracking of resonant
frequency. This paper presents possible solution of the amplitude-frequency control of EMVF and corresponding simulation and experimental results.
Uploads
Papers by Ana Djuric
the tool in any position in the 3D workspace. The wrist is used to orient the tool by rotation about X, Y and Z axis. This standard kinematic structure (3T3R) produces a rectangular workspace.
In this paper a full kinematic model for a 6DOF general CNC
(gantry) machine is presented, along with the Jacobian matrix and singularity analysis. Using Denavit-Hartenberg convention, firstly, the general kinematic structure is presented, in order to assign frames at each link. The forward kinematic problem is solved using Maple 17 software. Differential kinematics describes the analytical relationship between the joint motion and the end-effector motion in terms of velocities, through the manipulator Jacobian matrix. The configuration at which the manipulator Jacobian matrix drops rank is called singular configuration. In this paper the Jacobian matrix is derived using the vector cross multiplication method. The singularity conditions are examined and validated. The fully reachable workspace is plotted with Matlab tools using specified joint limits.
The presented solutions are expressed in parametric manner and can be used for analysis of the existing gantry type machine as well as a design tool for new machines.
electromagnetic vibratory feeders (EMVF) are commonly used for performing gravimetric flow of granular and particulate materials in processing industry. This drives offer easy and simple control the mass flow of conveying materials. In comparison with other drives (pneumatics,
inertial, centrifugal, etc...), these have a more simple construction and they are compact, robust and reliable in operation. The absence of wearing mechanical part, such as gears, cams belts, bearings, eccentrics, etc., makes EMVF, most economical equipment. Standard power electronic
output stages intended for control of the EMVF using SCR devices (thyristors and triacs). This implies phase angle control (PAC) and constant frequency of vibration. In this way control circuit must be synchronized to the mains supply frequency 50(60) Hz. PAC can only accomplish tuning amplitude of vibration, but not vibratory frequency.
Application of transistor (IGBT or MOSFET) switch mode power converters enables accomplishing the amplitude and (or) frequency control of EMVF. Their use implies the excitation of an EMVF independent of the mains supply frequency. In addition, the frequency control ensures
operation in the region of mechanical resonance. This operation is highly efficient, because large output displacement is provided by small input power. An optimal and efficient operation requires tracking of resonant
frequency. This paper presents possible solution of the amplitude-frequency control of EMVF and corresponding simulation and experimental results.
the tool in any position in the 3D workspace. The wrist is used to orient the tool by rotation about X, Y and Z axis. This standard kinematic structure (3T3R) produces a rectangular workspace.
In this paper a full kinematic model for a 6DOF general CNC
(gantry) machine is presented, along with the Jacobian matrix and singularity analysis. Using Denavit-Hartenberg convention, firstly, the general kinematic structure is presented, in order to assign frames at each link. The forward kinematic problem is solved using Maple 17 software. Differential kinematics describes the analytical relationship between the joint motion and the end-effector motion in terms of velocities, through the manipulator Jacobian matrix. The configuration at which the manipulator Jacobian matrix drops rank is called singular configuration. In this paper the Jacobian matrix is derived using the vector cross multiplication method. The singularity conditions are examined and validated. The fully reachable workspace is plotted with Matlab tools using specified joint limits.
The presented solutions are expressed in parametric manner and can be used for analysis of the existing gantry type machine as well as a design tool for new machines.
electromagnetic vibratory feeders (EMVF) are commonly used for performing gravimetric flow of granular and particulate materials in processing industry. This drives offer easy and simple control the mass flow of conveying materials. In comparison with other drives (pneumatics,
inertial, centrifugal, etc...), these have a more simple construction and they are compact, robust and reliable in operation. The absence of wearing mechanical part, such as gears, cams belts, bearings, eccentrics, etc., makes EMVF, most economical equipment. Standard power electronic
output stages intended for control of the EMVF using SCR devices (thyristors and triacs). This implies phase angle control (PAC) and constant frequency of vibration. In this way control circuit must be synchronized to the mains supply frequency 50(60) Hz. PAC can only accomplish tuning amplitude of vibration, but not vibratory frequency.
Application of transistor (IGBT or MOSFET) switch mode power converters enables accomplishing the amplitude and (or) frequency control of EMVF. Their use implies the excitation of an EMVF independent of the mains supply frequency. In addition, the frequency control ensures
operation in the region of mechanical resonance. This operation is highly efficient, because large output displacement is provided by small input power. An optimal and efficient operation requires tracking of resonant
frequency. This paper presents possible solution of the amplitude-frequency control of EMVF and corresponding simulation and experimental results.