Omnidirectional mobile manipulator, which is composed by a three DOF omnidirectional mobile platform and a mounted manipulator, can move in any direction at any time. By reason of the redundantly actuated mechanism, t...
详细信息
Omnidirectional mobile manipulator, which is composed by a three DOF omnidirectional mobile platform and a mounted manipulator, can move in any direction at any time. By reason of the redundantly actuated mechanism, the omnidirectional motion property of the mobile platform is similar to the parallel manipulator cooperatively manipulating objects, which admits internal force doing none contribution to the motion of the platform. Thus, the internal force should be controlled to reduce energy waste. Therefore, a stable PD controller is developed first for motion control of the integrated mobile manipulator system. Then, by treating the motion induced force as disturbance, a feed forward plus PI type force controller is addressed to regulate the internal force to zero. Finally, simulation results demonstrate the validity of the proposed approach.
In comparison with conventional electromagnetic motors, ultrasonic motors have many advantages such as a large torque at the low velocity, good controllability, rapid response, quiet operation, simple structure and no...
详细信息
In comparison with conventional electromagnetic motors, ultrasonic motors have many advantages such as a large torque at the low velocity, good controllability, rapid response, quiet operation, simple structure and non electromagnetic field induction, etc. These features have led to the development of various ultrasonic motors in many industrial fields. Hence, in this study, ultrasonic linear motor using multilayer structured ceramic actuator was designed and simulated using ANSYS of finite element method(FEM) simulator for investigating the optimum conditions of it. The ultrasonic linear motor studied in this paper was designed using the 1st longitudinal (L 1 ) and 4th bending (B 4 ) vibration. The size of ceramic actuator is 15 mm long and 5 mm wide. And one-layer thickness of actuator is 60 mu m. The dimension of linear motor is 61 times 5 times 3 mm. The sectional size of projection is 1.5 times 5 mm. The driving voltage of the motor was very low as 5 Vrms. With the increase of the number of piezoelectric ceramic layers, displacement of node was increased up to 21 layered ceramic actuator and then decreased. Maximum z displacement of node was about 7.02 mum at the 21 layered ultrasonic motor.
Over the last ten years, monitors of depth of anesthesia have progressively been integrated in the clinical practice. Based on the analysis of the electroencephalogram (EEG), these monitors deliver an index that helps...
详细信息
Over the last ten years, monitors of depth of anesthesia have progressively been integrated in the clinical practice. Based on the analysis of the electroencephalogram (EEG), these monitors deliver an index that helps the anesthesiologist to determine the state of the patient during the surgery. Although they employ different kind of algorithms, spectral parameters are always taken into account to achieve the final indexes. In this work, a new spectral parameter based on the cumulative power spectrum is proposed. When compared to the Spectral Edge Frequency (SEF), a classic spectral parameter, the Cumulative Power Spectrum Index (CPSI) presents a higher correlation with reference indexes (AAI, BIS and CePROP) and a higher prediction probability of the state of the patient. Furthermore, when compared to the reference indexes, the CPSI shows similar performances in terms of correlation and presents a higher prediction probability than two of them (BIS and CePROP).
作者:
M. FeemsterD.M. DawsonA. BehalW. DixonMatthew Feemster received the B.S degree in Electrical Engineering from Clemson University
Clemson South Carolina in December 1994. Upon graduation he remained at Clemson University and received the M.S. degree in Electrical Engineering in 1997. During this time he also served as a research/teaching assistant. His research work focused on the design and implementation of various nonlinear control algorithms with emphasis on the induction motor and mechanical systems with friction present. He is currently working toward his Ph.D. degree in Electrical Engineering at Clemson University. Darren M. Dawson was born in 1962
in Macon Georgia. He received an Associate Degree in Mathematics from Macon Junior College in 1982 and a B.S. Degree in Electrical Engineering from the Georgia Institute of Technology in 1984. He then worked for Westinghouse as a control engineer from 1985 to 1987. In 1987 he returned to the Georgia Institute of Technology where he received the Ph.D. Degree in Electrical Engineering in March 1990. During this time he also served as a research/teaching assistant. In July 1990 he joined the Electrical and Computer Engineering Department and the Center for Advanced Manufacturing (CAM) at Clemson University where he currently holds the position of Professor. Under the CAM director's supervision he currently leads the Robotics and Manufacturing Automation Laboratory which is jointly operated by the Electrical and Mechanical Engineering departments. His main research interests are in the fields of nonlinear based robust adaptive and learning control with application to electro-mechanical systems including robot manipulators motor drives magnetic bearings flexible cables flexible beams and high-speed transport systems. Aman Behal was born in India in 1973. He received his Masters Degree in Electrical Engineering from Indian Institute of Technology
Bombay in 1996. He is currently working towards a Ph.D in Controls and Robotics at Clemson University. His research focuses on the control of no
In this paper, we extend the observer/control strategies previously published in [25] to an n -link, serially connected, direct drive, rigid link, revolute robot operating in the presence of nonlinear friction effects...
详细信息
In this paper, we extend the observer/control strategies previously published in [25] to an n -link, serially connected, direct drive, rigid link, revolute robot operating in the presence of nonlinear friction effects modeled by the Lu-Gre model. In addition, we also present a new adaptive control technique for compensating for the nonlinear parameterizable Stribeck effects. Specifically, an adaptive observer/controller scheme is developed which contains a feedforward approximation of the Stribeck effects. This feedforward approximation is used in a composite controller/observer strategy which forces the average square integral of the position tracking error to an arbitrarily small value. Experimental results are included to illustrate the performance of the proposed controllers.
The paper addresses the problem of scheduling tasks represented by a directed acyclic graph (DAG) on distributed environments. Due to the task, communication and resource constraints, the resource matching and task sc...
详细信息
A typical servicing operation in space mainly includes three phases: capturing the target, berthing and docking the target, and repairing the target. The attitude of a satellite usually changes after the capturing, be...
详细信息
Smith Predictor is very sensitive to uncertain system with variable time-delay. Using dual-locus diagram method, we first analyse the essence of Smith Predictor's sensitivity and present a proposition to illustrat...
详细信息
Recently, a capsule endoscope has been developed to observe images from the inside of intestine. Such a capsule endoscope does not have locomotion or hold method. To get proper diagnosis and medication, it is necessar...
详细信息
ISBN:
(纸本)0889865787
Recently, a capsule endoscope has been developed to observe images from the inside of intestine. Such a capsule endoscope does not have locomotion or hold method. To get proper diagnosis and medication, it is necessary to control the capsule from outside to guide locomotion. The designed and implemented capsule has feasibility to contract the small intestine by electrical stimuli through the electrodes. When the small intestine is contracted by electrical stimuli, the capsule can move to opposite direction, which means the capsule can go up and down in the small intestine. The implemented stimuli capsule always monitors excessive energy transmission and automatically shuts down the electrical stimuli to make it more secure. Additionally, the stimuli capsule goes on standby mode to save the battery, and it can be reset by comparator circuit which is connected to stimulus electrodes. To verify the design and implement the stimuli capsule, in-vitro experiments were performed with pig's small intestine.
Electrogastrography (EGG) is a significant reference of the myoelectric activity of the gastrointestinal tract and indicates whether it has a disease or not. There have been numerous studies of the myoelectric activit...
详细信息
ISBN:
(纸本)0889865787
Electrogastrography (EGG) is a significant reference of the myoelectric activity of the gastrointestinal tract and indicates whether it has a disease or not. There have been numerous studies of the myoelectric activity in a stomach, but only a few studies of the intestines because of the difficulty of measurement in the intestines. Recently, the technology of the biotelemetry capsule for measurement of internal information in the human digestive tract has been developed. In the current study, an EGG telemetry system using the developed biotelemetry technology was designed and implemented for measuring EGG in intestines. The EGG capsule converts the acquired EGG value to digital data, which is transmitted from the capsule to the external receiver. The performance of the telemetry capsule for the EGG monitoring in the gastrointestinal tract was verified by in-vitro animal experiments. From the experiment, it was verified that the EGG telemetry capsule can measures a slow wave in intestines.
暂无评论