An effective way for the testing of a large number of systems is using single and multi-axis shak... more An effective way for the testing of a large number of systems is using single and multi-axis shaking tables. Among the possible applications, the civil engineering field stands out for the testing of structures, or part of them, to high natural dynamic forces. However, due to nonlinearities and structured and unstructured uncertainties of the hydraulic systems, the acceleration signal of these systems with respect to sine input are distorted. This paper is focused on identification of a gray-box acceleration model of a uni-axial servo hydraulic shaking table with respect to sine input signal with different frequencies and amplitude. First, a full system model of servo hydraulic system is developed based on fluid mechanical expressions and steady state friction. Second, for each input frequencies the unknown parameters of the friction, bulk modulus and leakage of the system are identified based on nonlinear least square method. Then, the identified parameters are used to develop a dy...
BATH/ASME 2016 Symposium on Fluid Power and Motion Control, 2016
An effective way for the testing of a large number of systems is using single and multi-Axis shak... more An effective way for the testing of a large number of systems is using single and multi-Axis shaking tables. Among the possible applications, the civil engineering field stands out for the testing of structures, or part of them, both on a reduced and on a full scale. However, design a high performance controller for a servo-hydraulic shaking table is a difficult problem due to its non-linarites and large friction forces. The goal of this pa- per is to develop and experimentally validate a robust numerical model that simulates the acceleration behavior of a uni-Axial servo-hydraulic shaking table system with considering three friction models, the LuGre model, the modified LuGre model and the new modified LuGre model. First, a full system model of servo- hydraulic system is developed based on fluid mechanical expressions and then the friction force of hydraulic cylinder is modeled and validated on the real shaking table. Data of the experiment are gathered from input command valve, and the output acceleration and position of the table. All models are simulated by using MATLAB and SIMULINK computer program. The parameters of the system and the friction models are estimated by using least square method (LSM). Finally, the comparisons of simulated reults with experimental ones show that the model of the system with considering third model of the friction can predict accurately the shaking table's behaviors.
Over the last decades, both force sensors and cameras have developed as useful sensors for differ... more Over the last decades, both force sensors and cameras have developed as useful sensors for different applications in robotics. This thesis considers a number of dynamic visual tracking and control problems, as well as the integration of these techniques with contact force control. Different topics ranging from basic theory to system implementation and applications are treated. It addresses the use of monocular eye-in-hand machine vision to control the position of a robot manipulator for dynamically challenging tasks. Such tasks are defined as those where the robot motion required approaches or exceeds the performance limits stated by the manufacturer. Computer vision systems have been used for robot control for over four decades now, but have rarely been used for high-performance visual closed-loop control. This has largely been due to technological limitations in image processing, but since the mid 2010s advances have made it feasible to apply computer vision techniques at a suffic...
2011 UKSim 5th European Symposium on Computer Modeling and Simulation, 2011
i n t h i s p a p e r , t h e n o n -s t a t i o n a r y n o i s e s a r e challenged by an onlin... more i n t h i s p a p e r , t h e n o n -s t a t i o n a r y n o i s e s a r e challenged by an online averaging wavelet method filter. The novelty of the filter is using averaging method of combining mean values of each resolution in approximation spaces that computes the average overall frequency in a specific point. The key structure is a mirror usage of data handling the zero abnormality of the filter in time boundaries. this algorithm is usable for jobs with need of elimination noise that knowing the harmonics is less needed and the smoothing of the conventional filters are much that the data would be deleted. After using this algorithm if needed the conventional low-pass filters can be used to extract smoothed data. This method simplicity is appropriate for micro-controller systems.
2011 3rd International Conference on Computer Research and Development, 2011
In this paper, a fast wavelet denoising by Averaging Wavelet Method (AWM) for digital communicati... more In this paper, a fast wavelet denoising by Averaging Wavelet Method (AWM) for digital communications will be proposed. This method is appropriate for the low bit operational communication installation in microcontrollers, at industrial noisy environments, over long wires.
2013 3rd Joint Conference of AI & Robotics and 5th RoboCup Iran Open International Symposium, 2013
In this paper, a sliding mode controller with a generalized ℋ2 performance is proposed for a unic... more In this paper, a sliding mode controller with a generalized ℋ2 performance is proposed for a unicycle-like mobile robot to implement the trajectory tracking mission. First, a kinematic controller is introduced for the mobile robot and generating the desired values of the linear and angular velocity for the dynamic controller. Secondly, a dynamic controller based on the sliding mode control with a generalized ℋ 2 performance is proposed to make the real velocity of the mobile robot and reach the desired velocity command. The stability properties of the controllers are proved by the Lyapunov method. This control law providing smaller errors and better performance to deal with the slipping of the wheels and parameter uncertainty. Simulation is carried out for a mobile robot to verify the performance of the proposed control scheme.
An effective way for the testing of a large number of systems is using single and multi-axis shak... more An effective way for the testing of a large number of systems is using single and multi-axis shaking tables. Among the possible applications, the civil engineering field stands out for the testing of structures, or part of them, to high natural dynamic forces. However, due to nonlinearities and structured and unstructured uncertainties of the hydraulic systems, the acceleration signal of these systems with respect to sine input are distorted. This paper is focused on identification of a gray-box acceleration model of a uni-axial servo hydraulic shaking table with respect to sine input signal with different frequencies and amplitude. First, a full system model of servo hydraulic system is developed based on fluid mechanical expressions and steady state friction. Second, for each input frequencies the unknown parameters of the friction, bulk modulus and leakage of the system are identified based on nonlinear least square method. Then, the identified parameters are used to develop a dy...
BATH/ASME 2016 Symposium on Fluid Power and Motion Control, 2016
An effective way for the testing of a large number of systems is using single and multi-Axis shak... more An effective way for the testing of a large number of systems is using single and multi-Axis shaking tables. Among the possible applications, the civil engineering field stands out for the testing of structures, or part of them, both on a reduced and on a full scale. However, design a high performance controller for a servo-hydraulic shaking table is a difficult problem due to its non-linarites and large friction forces. The goal of this pa- per is to develop and experimentally validate a robust numerical model that simulates the acceleration behavior of a uni-Axial servo-hydraulic shaking table system with considering three friction models, the LuGre model, the modified LuGre model and the new modified LuGre model. First, a full system model of servo- hydraulic system is developed based on fluid mechanical expressions and then the friction force of hydraulic cylinder is modeled and validated on the real shaking table. Data of the experiment are gathered from input command valve, and the output acceleration and position of the table. All models are simulated by using MATLAB and SIMULINK computer program. The parameters of the system and the friction models are estimated by using least square method (LSM). Finally, the comparisons of simulated reults with experimental ones show that the model of the system with considering third model of the friction can predict accurately the shaking table's behaviors.
Over the last decades, both force sensors and cameras have developed as useful sensors for differ... more Over the last decades, both force sensors and cameras have developed as useful sensors for different applications in robotics. This thesis considers a number of dynamic visual tracking and control problems, as well as the integration of these techniques with contact force control. Different topics ranging from basic theory to system implementation and applications are treated. It addresses the use of monocular eye-in-hand machine vision to control the position of a robot manipulator for dynamically challenging tasks. Such tasks are defined as those where the robot motion required approaches or exceeds the performance limits stated by the manufacturer. Computer vision systems have been used for robot control for over four decades now, but have rarely been used for high-performance visual closed-loop control. This has largely been due to technological limitations in image processing, but since the mid 2010s advances have made it feasible to apply computer vision techniques at a suffic...
2011 UKSim 5th European Symposium on Computer Modeling and Simulation, 2011
i n t h i s p a p e r , t h e n o n -s t a t i o n a r y n o i s e s a r e challenged by an onlin... more i n t h i s p a p e r , t h e n o n -s t a t i o n a r y n o i s e s a r e challenged by an online averaging wavelet method filter. The novelty of the filter is using averaging method of combining mean values of each resolution in approximation spaces that computes the average overall frequency in a specific point. The key structure is a mirror usage of data handling the zero abnormality of the filter in time boundaries. this algorithm is usable for jobs with need of elimination noise that knowing the harmonics is less needed and the smoothing of the conventional filters are much that the data would be deleted. After using this algorithm if needed the conventional low-pass filters can be used to extract smoothed data. This method simplicity is appropriate for micro-controller systems.
2011 3rd International Conference on Computer Research and Development, 2011
In this paper, a fast wavelet denoising by Averaging Wavelet Method (AWM) for digital communicati... more In this paper, a fast wavelet denoising by Averaging Wavelet Method (AWM) for digital communications will be proposed. This method is appropriate for the low bit operational communication installation in microcontrollers, at industrial noisy environments, over long wires.
2013 3rd Joint Conference of AI & Robotics and 5th RoboCup Iran Open International Symposium, 2013
In this paper, a sliding mode controller with a generalized ℋ2 performance is proposed for a unic... more In this paper, a sliding mode controller with a generalized ℋ2 performance is proposed for a unicycle-like mobile robot to implement the trajectory tracking mission. First, a kinematic controller is introduced for the mobile robot and generating the desired values of the linear and angular velocity for the dynamic controller. Secondly, a dynamic controller based on the sliding mode control with a generalized ℋ 2 performance is proposed to make the real velocity of the mobile robot and reach the desired velocity command. The stability properties of the controllers are proved by the Lyapunov method. This control law providing smaller errors and better performance to deal with the slipping of the wheels and parameter uncertainty. Simulation is carried out for a mobile robot to verify the performance of the proposed control scheme.
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