In this paper we present a novel method of detecting anatomical structures from liver ultrasound images. Local texture anisotropy is evaluated using a specially designed bank of Gabor filters. We show that the propose...
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ISBN:
(纸本)9781424467259
In this paper we present a novel method of detecting anatomical structures from liver ultrasound images. Local texture anisotropy is evaluated using a specially designed bank of Gabor filters. We show that the proposed method is well suited for processing liver ultrasound images and it is robust with respect to its parameters. A practical application of this method is then presented. Image features are computed on detected structures. These features are then used in conjunction with a classifier (Support Vector Machines) to discriminate between left and right lobe liver images. This classifier is used to label ultrasound images. The labeling algorithm obtained a very low error rate (<1%). It can successfully replace the human expert in image labeling.
In certain robot applications, path planning has to be viewed, not only from a motion perspective, but also from a process perspective. In 3-dimensional Friction Stir Welding (FSW) a properly planned path is essential...
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ISBN:
(纸本)9789728865832
In certain robot applications, path planning has to be viewed, not only from a motion perspective, but also from a process perspective. In 3-dimensional Friction Stir Welding (FSW) a properly planned path is essential for the outcome of the process, even though different control loops compensate for various deviations. One such example is how sharp path intersection is handled, which is the emphasis in this paper. We propose a strategy based on Hermite and Bezier curves, by which G(1) continuity is obtained. The blending operation includes an optimization strategy in order to avoid high second order derivatives of the blending polynomials, yet still to cover as much as possible of the original path.
The development of an algorithm to achieve optimal cyclic gaits in space for a thirteen-link biped and twelve actuated joints is proposed. The cyclic walking gait is composed of successive single support phases and im...
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ISBN:
(纸本)9789728865832
The development of an algorithm to achieve optimal cyclic gaits in space for a thirteen-link biped and twelve actuated joints is proposed. The cyclic walking gait is composed of successive single support phases and impulsive impacts with full contact between the sole of the feet and the ground. The evolution of the joints are chosen as spline functions. The parameters to define the spline functions are determined using an optimization under constraints on the dynamic balance, on the ground reactions, on the validity of impact, on the torques and on the joints velocities. The criterion considered is represented by the integral of the torque norm. The algorithm is tested for a biped robot whose numerical walking results are presented.
This study presents a novel approach to Human-Robot Interaction (HRI) by employing gesture recognition to control robotic systems, such as bionic arms or manipulators, through accelerometer-based data collection. Usin...
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To satisfy the grinding requirements of all kinds of worm tooth surface, a novel CNC worm grinding machine is demonstrated in this paper. Based on the generating theory, the mathematical models of the worm tooth surfa...
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ISBN:
(纸本)9781728186382
To satisfy the grinding requirements of all kinds of worm tooth surface, a novel CNC worm grinding machine is demonstrated in this paper. Based on the generating theory, the mathematical models of the worm tooth surface is developed. A novel structure of the worm grinding machine is proposed based on the virtual center distance manufacturing principle, and a seven-axis four-linkage CNC worm grinding machine is developed to verify the practicability of the new structure. A sample of hourglass worm tooth surface is ground on this novel CNC worm grinding machine, the accuracy of hourglass worm tooth surface is certificated by the accuracy detection and contact area test, which proves that the accuracy of this sample is up to level 5. This study is expected to provide a theoretical foundation and experimental support for the grinding of hourglass worm tooth surface.
The paper considers the problem of predictive control with actuator or sensor failures. The problem is to show in what configuration (i.e. for what prediction horizons) the adaptive generalized predictive control can ...
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ISBN:
(纸本)9789897583049
The paper considers the problem of predictive control with actuator or sensor failures. The problem is to show in what configuration (i.e. for what prediction horizons) the adaptive generalized predictive control can tolerate these failures, assuring similar performance in comparison with the case without failures. The results are shown on the basis of experiments conducted on the laboratory stand with a servo drive coupled with a mechanical backlash module to mimic actuator/sensor failures, and with a magnetic brake, to show the performance in the case of occurrence of an unexpected load.
In this paper, an EtherCAT scanning mirror system with function of NURBS path tracking control was investigated. By using EtherCAT protocol to connect master computer with a scanning mirror system, we did a first atte...
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ISBN:
(纸本)9781538666630
In this paper, an EtherCAT scanning mirror system with function of NURBS path tracking control was investigated. By using EtherCAT protocol to connect master computer with a scanning mirror system, we did a first attempt to implement position control by the master computer, so that one can apply an advanced control algorithm to the system instead of applying a distributed control algorithm on the proprietary driver of the slave device. The technical issue of this configuration like commutation delay caused by the three-buffer-mode is addressed. A two-staged H-infinity with feed-forwardcontroller is designed for the position control loop. Moreover, considering the widely used of non-uniform rational B-spline (NURBS) in the field of CAD/CAM, we added the function of NURBS path planning in the controller so that the system can deal with complex NURBS curves. The experiment results showed that the proposed method can reduce tracking error and have better performance when comparing with traditional distributed control strategy.
In this paper, to study the effect of different control approaches on improving trajectory tracking accuracy for a 3 degree-of-freedom (DOF) planar parallel robot, we tested two synchronized-type controllers: PI-type ...
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ISBN:
(纸本)9781424403417
In this paper, to study the effect of different control approaches on improving trajectory tracking accuracy for a 3 degree-of-freedom (DOF) planar parallel robot, we tested two synchronized-type controllers: PI-type synchronized control and adaptive synchronized (A-S) control;and conventional PEE) control and adaptive control. Here PID control and PI-type synchronized control are dynamic model-free while the adaptive control and A-S control are dynamic model-based. Because of the closed-loop kinematic chain mechanism of the experimental planar parallel robot used in this study, trajectory tracking control of this robot may be treated as a synchronization problem, and consequently, use of the synchronized control approaches can substantially improve the trajectory tracking performance of the robot end-effector compared with approaches without synchronization. Through conducting experiments on an experimental 3-DOF P-R-R type planar parallel robot by using the four control approaches, the above claims are demonstrated.
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