Target tracking control for wheeled mobile robot (WMR) need resolve the problems of kinematics model and tracking ***-order sliding mode control is a valid method used in the nonlinear tracking control system,which ...
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Target tracking control for wheeled mobile robot (WMR) need resolve the problems of kinematics model and tracking ***-order sliding mode control is a valid method used in the nonlinear tracking control system,which can eliminate the chattering of sliding mode *** there lacks the research of robustness and uncertain factors for high-order sliding mode *** address the fast convergence and robustness problems of tracking target,the tracking mathematical model of WMR and the target is *** on the finite-time convergence theory and second order sliding mode method,a nonlinear tracking algorithm is designed which guarantees that WMR can catch the target in finite *** the same time an observer is applied to substitute the uncertain acceleration of the target,then a smooth nonlinear tracking algorithm is *** on Lyapunov stability theory and finite-time convergence,a finite time convergent smooth second order sliding mode controller and a target tracking algorithm are designed by using second order sliding mode *** simulation results verified that WMR can catch up the target quickly and reduce the control discontinuity of the velocity of WMR.
While executing tasks such as ocean pollution monitoring,maritime rescue,geographic mapping,and automatic navigation utilizing remote sensing images,the coastline feature should be *** methods are not satisfactory to ...
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While executing tasks such as ocean pollution monitoring,maritime rescue,geographic mapping,and automatic navigation utilizing remote sensing images,the coastline feature should be *** methods are not satisfactory to extract coastline in high-resolution panchromatic remote sensing *** contour model,also called snakes,have proven useful for interactive specification of image contours,so it is used as an effective coastlines extraction ***,coastlines are detected by water segmentation and boundary tracking,which are considered initial contours to be optimized through active contour *** better energy functions are developed,the power assist of snakes becomes *** internal energy has been done to reduce problems caused by convergence to local minima,and new external energy can greatly enlarge the capture region around features of *** normalization processing,energies are iterated using greedy algorithm to accelerate convergence *** experimental results encompassed examples in images and demonstrated the capabilities and efficiencies of the improvement.
Cavity adjustment is a critical step for manufacturing laser gyro. Location relation of the laser facula and the aperture images should be detected to provide control information for the movement of the cavity adjustm...
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A double cylinders type traveling wave ultrasonic motor using composite transducer was *** proposed stator contained two cylinders and one composite transducer,and the transducer located on the outer surfaces of *** c...
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A double cylinders type traveling wave ultrasonic motor using composite transducer was *** proposed stator contained two cylinders and one composite transducer,and the transducer located on the outer surfaces of *** composite transducer included two exponential horns located on leading ends,and the horns insected with the cylinders at tip *** degenerated flexural vibration modes spatially and temporally orthogonal to each other were excited in each cylinder by the composite *** this new design,a single transducer could excite two flexural traveling waves in the ***,elliptical motions were achieved at the particles on the *** working principle of the proposed motor was *** cylinder and transducer were designed with *** resonant frequencies of two vibration modals of the stator were tuned to be the same,and the motion trajectories of nodes on the teeth were *** analysis results show that the motion trajectories of teeth are *** results of this paper can guide the development of this new type of ultrasonic motor.
To take advantage of merits of higher output-power and efficiency of bolt-clamped transducer,a T-type linear ultrasonic motor was proposed in this *** proposed motor contained a horizontal transducer and a vertical **...
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To take advantage of merits of higher output-power and efficiency of bolt-clamped transducer,a T-type linear ultrasonic motor was proposed in this *** proposed motor contained a horizontal transducer and a vertical *** horizontal transducer included two exponential shape horns,and the vertical transducer contained one exponential shape *** the horns intersected at tip ends where a driving foot was *** longitudinal vibrations of transducers were excited by the stretching vibration of PZT *** vibrations were superimposed in the motor and generated elliptical trajectory at the driving *** actuating mechanism of the proposed motor was *** two working modals of the motor were gained with *** resonant frequencies of two working modals were degenerated by adjusting the structural *** motion trajectory of nodes on the driving foot was gained by transient *** vibration amplitude of node on the driving foot indicates that the proposed motor has potential good output *** results verify the feasibility of the proposed design and provide instructions for the development of the new ultrasonic motor.
The disadvantages of classic ring type ultrasonic motor were *** obtain large mechanical output power,a ring type standing wave ultrasonic motor using cantilever type longitudinal transducers was *** are four pairs of...
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The disadvantages of classic ring type ultrasonic motor were *** obtain large mechanical output power,a ring type standing wave ultrasonic motor using cantilever type longitudinal transducers was *** are four pairs of cantilevers on one side of the ring,and four PZT ceramics are set between each pair of cantilevers.A screw fastened the PZT ceramics and cantilevers together to form a longitudinal *** bending vibration mode of the ring is excited by the stretching vibration of the PZT ***,linear simple harmonic motions are achieved at the particle on the *** the driving force is the frictional force between rotor and *** working principle of the proposed motor was *** ring and the longitudinal transducer were designed with *** sensitive parameters of resonant frequency of the transducer and ring could be gained with modal *** longitudinal vibration modal of transducer and bending vibration modal of ring were degenerated,and the motion trajectories of nodes on the teeth were *** results of this paper could guide the development of this new type of motor.
A model-free set-point tracking control approach of multi-fingered robot hand is *** set-point tracking controller,which has the structural form of PD controller,is composed with a combination of feedforward term,feed...
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A model-free set-point tracking control approach of multi-fingered robot hand is *** set-point tracking controller,which has the structural form of PD controller,is composed with a combination of feedforward term,feedback term and saturation control *** controller does not require the explicit use of dynamic modeling *** performed on the HIT/DLR hand demonstrate the effectiveness of the proposed approach in performance improvement and real-time application.
A design method for equivalent mechanical character of manipulator is put forward to cut down ground mechanical experiment cost of manipulator and reflect its mechanical character more veritably. Furthermore, the para...
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A design method for equivalent mechanical character of manipulator is put forward to cut down ground mechanical experiment cost of manipulator and reflect its mechanical character more veritably. Furthermore, the parameters of mechanical analogue element of manipulator are optimized. Axletree rigidity and joint torsion rigidity are equivalently designed on the basis of manipulator structure principle. The parameters of mechanical analogue element of manipulator are optimized through objective obtained method. The comparison between mechanical analogue element and mass, centroidal coordinate, moment of inertia of centroid on each direction and other critical parameters of each mass module of the manipulator is made. The result shows that mechanical parameters between mechanical analogue element and each joint module are almost the same. The mechanical analogue element can satisfy experimental demand, thus reduceing the experimental cost of mechanical circumstance.
An optimal measurement pose number searching method was designed to improve the pose selection *** optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish ...
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An optimal measurement pose number searching method was designed to improve the pose selection *** optimal robot measurement configurations were added to an initial pre-selected optimal configuration set to establish a new configuration set for robot calibration one by *** root mean squares (RMS) of the errors of each end-effector poses after being calibrated by these configuration sets were *** optimal number of the configuration set corresponding to the least RMS of pose error was then *** based on those poses selected by this algorithm can get higher end-effector accuracy,meanwhile consumes less *** optimal pose set including optimal 25 measurement configurations is found during the *** errors after calibration by using these poses are 1.54,1.61 and 0.86 mm,and better than those before calibration which are 7.79,7.62 and 8.29 mm,even better than those calibrated by the random method which are 2.22,2.35 and 1.69 mm in directions X,Y and Z,respectively.
The generalized ESPRIT (GESPRIT) method extends the conventional ESPRIT estimator to estimate the directions-of-arrival (DOAs) of multiple incident signals by using the array with more general geometrical configur...
The generalized ESPRIT (GESPRIT) method extends the conventional ESPRIT estimator to estimate the directions-of-arrival (DOAs) of multiple incident signals by using the array with more general geometrical configurations, where the translational invariance structure is not required. Unfor-tunately, the GESPRIT has serious ambiguous DOA estimates in some scenarios, and its performance degrades severely at low signal-to-noise ration (SNR) and with a small number of snapshots. Although a polynomial version of a new GESPRIT (NGESPRIT) method was given, but its derivation and estimation performance are unavailable in published literature. In this paper, in order to overcome the ambiguity of the GESPRIT and improve the estimation performance, the NGESPRIT method is derived explicitly. Moreover, the equivalence between the proposed NGESPRIT method and the rank reduction (RARE) method is clarified, while the former is more computationally efficient than the latter. Finally the effectiveness of the NGESPRIT method is substantiated through numerical examples.
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