A complete modeling(including the actuator dynamics)of a robot manipulator that uses three-phase induction motors is presented in this paper.A control scheme is designed to synchronize robot manipulators actuated by i...A complete modeling(including the actuator dynamics)of a robot manipulator that uses three-phase induction motors is presented in this paper.A control scheme is designed to synchronize robot manipulators actuated by induction motors under a masterslave scheme in the case where the joint velocity of the slave robots is estimated.All of the research on the synchronization of robot manipulators assumes the use of ideal actuators to drive the joints;for that reason,in this work,a three-phase induction motor is considered to be a direct-drive actuator for each joint.An entire model of the mated system is obtained by a combination of the dynamics of the induction motor and robot manipulator.Thus,the synchronization control algorithm for a master-slave scheme in both the joint space and workspace of robot manipulators driven by induction motors is developed.An observer based on the entire model is proposed to estimate the joint velocity of the slave robot manipulators.Through the Lyapunov criterion,a stability analysis of the synchronization control with a velocity estimator is detailed.The analytical results show the synchronization and estimation errors are globally,uniformly,and ultimately bounded.Simulations with multiple robots demonstrate the performance of the proposed control algorithm.展开更多
Gait event detection is important for diagnosis and evaluation. This is a challenging endeavor due to subjectivity, high amount of data, among other problems. ANFIS （Artificial Neural Fuzzy Inference Systems）, ARX ...Gait event detection is important for diagnosis and evaluation. This is a challenging endeavor due to subjectivity, high amount of data, among other problems. ANFIS （Artificial Neural Fuzzy Inference Systems）, ARX （Autoregressive Models with Exogenous Variables）, OE （Output Error models）, NARX （Nonlinear Autoregressive Models with Exogenous Variables） and models based on NN （neural networks） were developed in order to detect gait events without the problems mentioned. The objective was to compare developed models＇ performance and determinate the most suitable model for gait events detection. Knee joint angle, heel foot switch and toe foot switch during normal walking in a treadmill were collected from a healthy volunteer. Gait events were classified by three experts in human motion. Experts＇ mean classification was obtained and all models were trained and tested with the collected data and experts＇ mean classification. Fit percentage was obtained to evaluate models performance. Fit percentages were： ANFIS： 79.49%, ARX： 68.8%, OE： 71.39%, NARX： 88.59%, NNARX： 67.66%, NNRARX： 68.25% and NNARMAX： 54.71%. NARX had the best performance for gait events classification. For ARX and OE, previous filtering is needed. NN＇s models showed the best performance for high frequency components, ANFIS and NARX were able to integrate criteria from three experts for gait analysis. NARX and ANFIS are suitable for gait event identification. Test with additional subjects is needed.展开更多
Industrial metrology deals with measurements in production environment. It concerns calibration procedures as well as control of measurement processes. Measuring devices have been evolving from manual theodolites, ele...Industrial metrology deals with measurements in production environment. It concerns calibration procedures as well as control of measurement processes. Measuring devices have been evolving from manual theodolites, electronic theodolites, robotic total stations, to a relatively new kind of laser-based systems known as laser trackers. Laser trackers are 3D coordinate measuring devices that accurately measure large （and relatively distant） objects by computing spatial coordinates of optical targets held against those objects. In addition, laser trackers are used to align truthfully large mechanical parts. However, such aligning can be done in moving parts, for instance during robot calibration in a welding line. In this case, serial robots are controlled in order to keep a prescribed trajectory to accomplish its task properly. Nevertheless, in spite of a good control algorithm design, as time goes by, deviations appear and a calibration process is necessary. It is well known that laser tracker systems are produced by very well established enterprises but their laser products may result expensive for some （small） industries. We offer two parallel robot-based laser tracker systems models whose implementation would result cheaper than sophisticated laser devices and takes advantage of the parallel robot bondages as accuracy and high payload. The types of parallel robots evaluated were 3-SPS-1-S and 6-PUS. Modelling of the parallel robots was done by analytical and numerical techniques. The latter includes classical and artificial intelligence-based algorithms. The control performance was evaluated between classical and intelligent controllers.展开更多
This paper shows detailed steps for modeling a quadcopter with Euler-Lagrange equations, followed by controlling it with intelligent control that includes states decoupling. In addition, this control shows non-convent...This paper shows detailed steps for modeling a quadcopter with Euler-Lagrange equations, followed by controlling it with intelligent control that includes states decoupling. In addition, this control shows non-conventional membership functions for the most instable states, in order to get a fast and effective response.展开更多
文摘A complete modeling(including the actuator dynamics)of a robot manipulator that uses three-phase induction motors is presented in this paper.A control scheme is designed to synchronize robot manipulators actuated by induction motors under a masterslave scheme in the case where the joint velocity of the slave robots is estimated.All of the research on the synchronization of robot manipulators assumes the use of ideal actuators to drive the joints;for that reason,in this work,a three-phase induction motor is considered to be a direct-drive actuator for each joint.An entire model of the mated system is obtained by a combination of the dynamics of the induction motor and robot manipulator.Thus,the synchronization control algorithm for a master-slave scheme in both the joint space and workspace of robot manipulators driven by induction motors is developed.An observer based on the entire model is proposed to estimate the joint velocity of the slave robot manipulators.Through the Lyapunov criterion,a stability analysis of the synchronization control with a velocity estimator is detailed.The analytical results show the synchronization and estimation errors are globally,uniformly,and ultimately bounded.Simulations with multiple robots demonstrate the performance of the proposed control algorithm.
文摘Gait event detection is important for diagnosis and evaluation. This is a challenging endeavor due to subjectivity, high amount of data, among other problems. ANFIS （Artificial Neural Fuzzy Inference Systems）, ARX （Autoregressive Models with Exogenous Variables）, OE （Output Error models）, NARX （Nonlinear Autoregressive Models with Exogenous Variables） and models based on NN （neural networks） were developed in order to detect gait events without the problems mentioned. The objective was to compare developed models＇ performance and determinate the most suitable model for gait events detection. Knee joint angle, heel foot switch and toe foot switch during normal walking in a treadmill were collected from a healthy volunteer. Gait events were classified by three experts in human motion. Experts＇ mean classification was obtained and all models were trained and tested with the collected data and experts＇ mean classification. Fit percentage was obtained to evaluate models performance. Fit percentages were： ANFIS： 79.49%, ARX： 68.8%, OE： 71.39%, NARX： 88.59%, NNARX： 67.66%, NNRARX： 68.25% and NNARMAX： 54.71%. NARX had the best performance for gait events classification. For ARX and OE, previous filtering is needed. NN＇s models showed the best performance for high frequency components, ANFIS and NARX were able to integrate criteria from three experts for gait analysis. NARX and ANFIS are suitable for gait event identification. Test with additional subjects is needed.
文摘Industrial metrology deals with measurements in production environment. It concerns calibration procedures as well as control of measurement processes. Measuring devices have been evolving from manual theodolites, electronic theodolites, robotic total stations, to a relatively new kind of laser-based systems known as laser trackers. Laser trackers are 3D coordinate measuring devices that accurately measure large （and relatively distant） objects by computing spatial coordinates of optical targets held against those objects. In addition, laser trackers are used to align truthfully large mechanical parts. However, such aligning can be done in moving parts, for instance during robot calibration in a welding line. In this case, serial robots are controlled in order to keep a prescribed trajectory to accomplish its task properly. Nevertheless, in spite of a good control algorithm design, as time goes by, deviations appear and a calibration process is necessary. It is well known that laser tracker systems are produced by very well established enterprises but their laser products may result expensive for some （small） industries. We offer two parallel robot-based laser tracker systems models whose implementation would result cheaper than sophisticated laser devices and takes advantage of the parallel robot bondages as accuracy and high payload. The types of parallel robots evaluated were 3-SPS-1-S and 6-PUS. Modelling of the parallel robots was done by analytical and numerical techniques. The latter includes classical and artificial intelligence-based algorithms. The control performance was evaluated between classical and intelligent controllers.
文摘This paper shows detailed steps for modeling a quadcopter with Euler-Lagrange equations, followed by controlling it with intelligent control that includes states decoupling. In addition, this control shows non-conventional membership functions for the most instable states, in order to get a fast and effective response.
