Structural design of a cartesian coordinate tooth-arrangement robot
Aiming to the problem of time-consuming and low precision of the traditional tooth-arrangement methods, a conception of a professional and miniature Cartesian coordinate type robot for tooth-arrangement was put forward in this paper. Based on the analysis of tooth-arrangement process, the design scheme of tooth-arrangement robot were determined. We also build the whole three-dimensional model of Cartesian coordinate type robot of tooth-arrangement after functional analysis of every function module of tooth-arrangement robot. Finally, the kinematics simulation analysis of robot model using ADAMS is performed, and the results indicates that it is feasible and practical to realize the scheme design and structural design of Cartesian coordinate tooth-arrangement robot.
Motion Control and Experimentation on the Dental Arch Generator Driven by Multi-motors
Aiming at the synchronous motion control of the dental arch generator with multi-motor drive,this paper analyzes the kinematics of the dental arch generator,and presents a hardware control scheme based on industrial personal computer and control card PC6401.Real-time closed loop synchronous control is realized for the dental arch generator based on multithreading technology and VC++6.0,and experiments on control and tooth-arrangement are performed with a multi- manipulator tooth-arrangement robot prototype.The experiment indicates that the application of multithreading technology to the control program prevents the main thread block in real-time control,and realizes parallel coordinated control for the dental arch generator.Error analysis and tooth-arrangement experimentation are made,and the results indicate that the control strategy and technical route can fulfill the requirements for motion speed and location precision.
An operational method for estimating signal to noise ratios from data acquired with imaging spectrometers
A method, using the concept of local means and local standard deviations of small imaging blocks and using a box counting procedure, has been developed for unsupervised estimation of the average signal to noise ratios of images in which the noise is additive. The method has been applied to simulated images with Gaussian noise, to images acquired with the Airborne Visible Infrared Imaging Spectrometer and with the Geophysical and Environmental Research Imaging Spectrometer. The method is compared with other techniques for estimating signal to noise ratios from imaging data. It is believed that the method is generally applicable to images having many small homogeneous blocks. Because the method does not take into account interband effects, it is not appropriate to use the method to estimate signal to noise ratios from images having nonnegligible interband radiometric calibration errors at spatial scales less than or equal to the size of the small imaging blocks used in the noise estimation.