This paper presents environmental disturbance rejection in a 2-DOF inertial stabilization system ... more This paper presents environmental disturbance rejection in a 2-DOF inertial stabilization system by a combination of feedback and feedforward control. For feedback control, sliding mode control and the line of sight (LOS) stabilization are used for compensation of the nonlinearities, model uncertainties, friction and disturbances from outside environment. Although our mechanisms are carefully designed with statically balance, the center of the gravity will changed due to the configuration change during moving of the gimbal relative to an aerial vehicle. The disturbance torque from unbalance mass and gimbal geometry is unavoidable under the effect of the vibration of the aerial vehicle, which will lead to degrade the systems accuracy. Since the acceleration of the aerial carrier, due to the disturbance torque, can be measured, a feedforward disturbance rejection can be generated to compensate the disturbance torque. The experimental results confirm the validity of the control design procedure for the two-axis gimbaled stabilization system. The proposed controller is capable enough to overcome the disturbances and the impact of LOS disturbances on the tracking performance.
A simple traction controller was derived from a model following control (MFC) using bilinear tran... more A simple traction controller was derived from a model following control (MFC) using bilinear transformation. The controller was simplified by adjusting some dynamic parameters. The experiments were conducted to evaluate the validity of the controller by comparing with the classical PD controller. In the experiments, while the traction controller can prevent slippage, tracking control performance needed to be improved. The feedforward compensation was added to reduce the traction error. The experimentation using the simple controller with feedforward shows that the position error has been reduced while maintaining the traction force between floor and wheels.
King Mongkut’s University of Technology North Bangkok International Journal of Applied Science and Technology, 2013
This paper presents a PC-cluster based multi-camera system for real-time multiple objects trackin... more This paper presents a PC-cluster based multi-camera system for real-time multiple objects tracking. The PC-cluster, a group of linked computers, is developed by using PCI-to-PCI data mover card to improve real-time processing performance and provide system scalability. Five processing modules have been designed and implemented to control system operations. Target objects are in spherical shape. Four IEEE-1394a cameras with hardwired synchronization are used for system testing. After identifying correspondence objects in different views, 3-D coordinates of each target have been reconstructed. Experimental results show that the system can identify and track multiple objects moving in 3-D space correctly. The maximum frame rate for tracking is 12 frames per second. In the near future, the system can be applied for specific application when additional processing modules are added to the system
Robot-assisted therapy is a new type of rehabilitation that allows for highly repetitive, intensi... more Robot-assisted therapy is a new type of rehabilitation that allows for highly repetitive, intensive, adaptable, and quantifiable physical training. It is increasingly being used to restore motor function, particularly in stroke survivors with upper limb paresis. The end-effector type robot allows natural movements without complex structure which is ideal for functional rehabilitation training. A 3D end-effector base on a five-bar linkage has been proposed to improve the common end-effector type that covers mechanical design, dynamic control strategy, and application of rehabilitation training or exercise. The dynamic controllers are deweighting with gravity compensation, passive mobilization or active assistive, and the virtual spring-damper wall concept. These controllers are used for developing functional rehabilitation training or exercise from an engineering point of view based on experiences in developing various types of rehabilitation robots. The experiments, based on the performance of the controllers, have been conducted with healthy subjects. The experimental results have shown very promising results and can be extended to various types of functional rehabilitation.
This paper addresses the relationship between the weight of DC moving-coil permanent-magnet motor... more This paper addresses the relationship between the weight of DC moving-coil permanent-magnet motors and the requirements for the driven motion. The requirements for motion are assumed to be made in terms of a maximum absolute velocity and a maximum absolute acceleration. A move consists of periods of maximum acceleration and periods of maximum velocity, so called trapezoidal velocity profiles. The load on the motor/drive-train is characterized by a maximum torque (or force) which is assumed to occur during a period of maximum acceleration. The DC motor is as~umed to be limited bi a maximu; torque applied magnetically to the armature (essentially a maximum current) and by a maximum armature speed. Within these constraints simple procedures f~r identifying the lightest motors are given. An analysis of several series of popular motors is provided which defines the current state-of-the-art for such motors.
This work concerns the design and development of a six degrees of freedom haptic device. The hapt... more This work concerns the design and development of a six degrees of freedom haptic device. The haptic device is used as the master arm for internet-based teleoperation purposes. For the experimentation, the Stewarl platform, the other parallel mechanism, is used as the slave arm ^ The force reflex from the slave arm is transmitted to the operator through the Tendon-Pulley train of the master arm. Virlual guidance can be implemented in the master arm to improve the maneuverability for the operators. Low ineftia, friction force, and backlash are minimized in the design. Singularity is also eliminated. The inverse and forward kinematics as well as the Jacobian of the master arm are derived. The closed-form solution of the forward kinematics can be obtained by installing 9 encoders, instead of 6. The end-point of the master arm is sent to the slave arrn as commands. The slave arm transforms the commands to joint variables by using the inverse kinematics of the slave arm. The experimental ...
Tracking an object in three dimensional space is a major issue in computer vision which is normal... more Tracking an object in three dimensional space is a major issue in computer vision which is normally solved through the extraction of representative features of the object. Two-dimenston coordinates of the series of these image features are used to compute the position of the object. A typical system uses a binocular stereovision system. For an environment with obstruction, two cameras only are not practical, multiple cameras are used instead. When multiple cameras are used, a certain similarity measure among extracted features from any two stereoscopic images helps to match the correspondences. In this way, a three-dimensional measurement can be obtained from the 2-D coordinates of the feafures extracted from the different cameras. In this paper, a multiple cameras system (four cameras) and PC-cluster (two microcomputers) are used for estimating both position and velocity of a specified moving object. Noise filtering and features extraction of images are performed in the PC-cluster ...
We developed a robot, CUREs (Chulalongkorn University Rehabilitation Robotic Exoskeleton system),... more We developed a robot, CUREs (Chulalongkorn University Rehabilitation Robotic Exoskeleton system), for upper extremity rehabilitation. The active assistive control strategy based on the impedance force control is developed and implemented to obtain assistive-resistive paths tracking for rehabilitation activities. The desired trajectory or rehabilitated training pattern for each specific patient need to be assigned first by a medical doctor and a physical therapy. The therapist can program the desired trajectory by guiding the patient arm based on the assigned path pattern and the set of via points will be stored and used for generating the desired trajectory. The desired trajectory will be stored specific for the patient and can be called back anytime. During the rehabilitation, the robot can assist and resist the patient’s arm to follow the desired trajectory. If the patient has difficulty moving his arm to track the desired path, the robot will help by adding more torque to help th...
Theory and Practice of Robots and Manipulators, 1985
A new strategy of robot operation, the bracing strategy, is presented. Under this strategy an arm... more A new strategy of robot operation, the bracing strategy, is presented. Under this strategy an arm is moved into position then rigidized by bracing against either the work piece or an auxiliary, static structure. Subsequent precision motion does not involve the entire arm, but only ...
2006 IEEE Conference on Robotics, Automation and Mechatronics, 2006
ABSTRACT The paper presents an output tracking technique for a balanced rod inverted pendulum bas... more ABSTRACT The paper presents an output tracking technique for a balanced rod inverted pendulum based on computed feedback linearization. For any given trajectory of pendulum, which is the output, the trajectory of rod position, which is the internal state, is determined such that the system is input state linearizable without state transformation. Both output and state are used to stabilize and also linearize the system. Once the system is linear, the trajectory control effort can be superimposed such that the system tracks the trajectory. The trajectory control effort is determined from the inverse of the feedback linearized system and thus bounded. In this way, the tracking error is asymptotically decreasing. Both simulation and experiment based on the ECP 505 balanced rod inverted pendulum are used to demonstrate and verify the technique
This paper presents environmental disturbance rejection in a 2-DOF inertial stabilization system ... more This paper presents environmental disturbance rejection in a 2-DOF inertial stabilization system by a combination of feedback and feedforward control. For feedback control, sliding mode control and the line of sight (LOS) stabilization are used for compensation of the nonlinearities, model uncertainties, friction and disturbances from outside environment. Although our mechanisms are carefully designed with statically balance, the center of the gravity will changed due to the configuration change during moving of the gimbal relative to an aerial vehicle. The disturbance torque from unbalance mass and gimbal geometry is unavoidable under the effect of the vibration of the aerial vehicle, which will lead to degrade the systems accuracy. Since the acceleration of the aerial carrier, due to the disturbance torque, can be measured, a feedforward disturbance rejection can be generated to compensate the disturbance torque. The experimental results confirm the validity of the control design procedure for the two-axis gimbaled stabilization system. The proposed controller is capable enough to overcome the disturbances and the impact of LOS disturbances on the tracking performance.
A simple traction controller was derived from a model following control (MFC) using bilinear tran... more A simple traction controller was derived from a model following control (MFC) using bilinear transformation. The controller was simplified by adjusting some dynamic parameters. The experiments were conducted to evaluate the validity of the controller by comparing with the classical PD controller. In the experiments, while the traction controller can prevent slippage, tracking control performance needed to be improved. The feedforward compensation was added to reduce the traction error. The experimentation using the simple controller with feedforward shows that the position error has been reduced while maintaining the traction force between floor and wheels.
King Mongkut’s University of Technology North Bangkok International Journal of Applied Science and Technology, 2013
This paper presents a PC-cluster based multi-camera system for real-time multiple objects trackin... more This paper presents a PC-cluster based multi-camera system for real-time multiple objects tracking. The PC-cluster, a group of linked computers, is developed by using PCI-to-PCI data mover card to improve real-time processing performance and provide system scalability. Five processing modules have been designed and implemented to control system operations. Target objects are in spherical shape. Four IEEE-1394a cameras with hardwired synchronization are used for system testing. After identifying correspondence objects in different views, 3-D coordinates of each target have been reconstructed. Experimental results show that the system can identify and track multiple objects moving in 3-D space correctly. The maximum frame rate for tracking is 12 frames per second. In the near future, the system can be applied for specific application when additional processing modules are added to the system
Robot-assisted therapy is a new type of rehabilitation that allows for highly repetitive, intensi... more Robot-assisted therapy is a new type of rehabilitation that allows for highly repetitive, intensive, adaptable, and quantifiable physical training. It is increasingly being used to restore motor function, particularly in stroke survivors with upper limb paresis. The end-effector type robot allows natural movements without complex structure which is ideal for functional rehabilitation training. A 3D end-effector base on a five-bar linkage has been proposed to improve the common end-effector type that covers mechanical design, dynamic control strategy, and application of rehabilitation training or exercise. The dynamic controllers are deweighting with gravity compensation, passive mobilization or active assistive, and the virtual spring-damper wall concept. These controllers are used for developing functional rehabilitation training or exercise from an engineering point of view based on experiences in developing various types of rehabilitation robots. The experiments, based on the performance of the controllers, have been conducted with healthy subjects. The experimental results have shown very promising results and can be extended to various types of functional rehabilitation.
This paper addresses the relationship between the weight of DC moving-coil permanent-magnet motor... more This paper addresses the relationship between the weight of DC moving-coil permanent-magnet motors and the requirements for the driven motion. The requirements for motion are assumed to be made in terms of a maximum absolute velocity and a maximum absolute acceleration. A move consists of periods of maximum acceleration and periods of maximum velocity, so called trapezoidal velocity profiles. The load on the motor/drive-train is characterized by a maximum torque (or force) which is assumed to occur during a period of maximum acceleration. The DC motor is as~umed to be limited bi a maximu; torque applied magnetically to the armature (essentially a maximum current) and by a maximum armature speed. Within these constraints simple procedures f~r identifying the lightest motors are given. An analysis of several series of popular motors is provided which defines the current state-of-the-art for such motors.
This work concerns the design and development of a six degrees of freedom haptic device. The hapt... more This work concerns the design and development of a six degrees of freedom haptic device. The haptic device is used as the master arm for internet-based teleoperation purposes. For the experimentation, the Stewarl platform, the other parallel mechanism, is used as the slave arm ^ The force reflex from the slave arm is transmitted to the operator through the Tendon-Pulley train of the master arm. Virlual guidance can be implemented in the master arm to improve the maneuverability for the operators. Low ineftia, friction force, and backlash are minimized in the design. Singularity is also eliminated. The inverse and forward kinematics as well as the Jacobian of the master arm are derived. The closed-form solution of the forward kinematics can be obtained by installing 9 encoders, instead of 6. The end-point of the master arm is sent to the slave arrn as commands. The slave arm transforms the commands to joint variables by using the inverse kinematics of the slave arm. The experimental ...
Tracking an object in three dimensional space is a major issue in computer vision which is normal... more Tracking an object in three dimensional space is a major issue in computer vision which is normally solved through the extraction of representative features of the object. Two-dimenston coordinates of the series of these image features are used to compute the position of the object. A typical system uses a binocular stereovision system. For an environment with obstruction, two cameras only are not practical, multiple cameras are used instead. When multiple cameras are used, a certain similarity measure among extracted features from any two stereoscopic images helps to match the correspondences. In this way, a three-dimensional measurement can be obtained from the 2-D coordinates of the feafures extracted from the different cameras. In this paper, a multiple cameras system (four cameras) and PC-cluster (two microcomputers) are used for estimating both position and velocity of a specified moving object. Noise filtering and features extraction of images are performed in the PC-cluster ...
We developed a robot, CUREs (Chulalongkorn University Rehabilitation Robotic Exoskeleton system),... more We developed a robot, CUREs (Chulalongkorn University Rehabilitation Robotic Exoskeleton system), for upper extremity rehabilitation. The active assistive control strategy based on the impedance force control is developed and implemented to obtain assistive-resistive paths tracking for rehabilitation activities. The desired trajectory or rehabilitated training pattern for each specific patient need to be assigned first by a medical doctor and a physical therapy. The therapist can program the desired trajectory by guiding the patient arm based on the assigned path pattern and the set of via points will be stored and used for generating the desired trajectory. The desired trajectory will be stored specific for the patient and can be called back anytime. During the rehabilitation, the robot can assist and resist the patient’s arm to follow the desired trajectory. If the patient has difficulty moving his arm to track the desired path, the robot will help by adding more torque to help th...
Theory and Practice of Robots and Manipulators, 1985
A new strategy of robot operation, the bracing strategy, is presented. Under this strategy an arm... more A new strategy of robot operation, the bracing strategy, is presented. Under this strategy an arm is moved into position then rigidized by bracing against either the work piece or an auxiliary, static structure. Subsequent precision motion does not involve the entire arm, but only ...
2006 IEEE Conference on Robotics, Automation and Mechatronics, 2006
ABSTRACT The paper presents an output tracking technique for a balanced rod inverted pendulum bas... more ABSTRACT The paper presents an output tracking technique for a balanced rod inverted pendulum based on computed feedback linearization. For any given trajectory of pendulum, which is the output, the trajectory of rod position, which is the internal state, is determined such that the system is input state linearizable without state transformation. Both output and state are used to stabilize and also linearize the system. Once the system is linear, the trajectory control effort can be superimposed such that the system tracks the trajectory. The trajectory control effort is determined from the inverse of the feedback linearized system and thus bounded. In this way, the tracking error is asymptotically decreasing. Both simulation and experiment based on the ECP 505 balanced rod inverted pendulum are used to demonstrate and verify the technique
Uploads
Papers by Viboon Sangveraphunsiri