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In order to solve the problem of small high-speed precision cylindrical roller, which is difficult to drive and the surface is easily damaged when doing dynamic unbalance detection due to the small size and light mass of the roller, this paper proposes a new drive method, using air flotation non-destructive support instead of V-block or cylindrical surface of the roller and other lossy contact support and air flotation electric spindle combined with vacuum suction cup instead of belt friction drive; establish a mathematical model of cylindrical roller force to study the force of cylindrical roller in the air flotation sleeve during the drive, and through the force analysis, it is shown that under the condition that the structural parameters and material parameters of the drive remain unchanged, the start-up speed of the drive depends on the load-bearing capacity of the air film on the cylindrical roller; the mathematical model of the air film load-bearing capacity and the thickness of the air film is established to study the changing characteristics of the air film load-bearing capacity in the air flotation sleeve, and the correctness of the mathematical model is verified through numerical calculation combined with simulation analysis; the test platform of the drive device based on the non destructive detection of cylindrical roller dynamic unbalance is built to further verify the feasibility of high-speed non-destructive drive of cylindrical rollers and to create favorable conditions for the development of the non-destructive detection instrument for small mass cylindrical rollers dynamic unbalance.

In order to solve the design and regulation problems of graded porous scaffolds, the triply periodic minimal surface (TPMS) that based on implicit function was taken as the pore unit for constructing the porous scaffolds. And the TPMS structure was controlled by selecting different types of TPMS and defining the distance function. The transition of different structures of TPMS was performed by the weight fusion method. And the dual contouring (DC) algorithm and octree algorithm were used to divide the solid model of the defect bone into hexahedral elements to determine the target assembly spatial. Through the coordinate transformation of the isoparametric element method, the pore units were mapped into the hexahedral elements to construct porous structure. Finally, a Boolean operation was used to obtain a bone scaffold model with porous structure. The examples showed that the gradient model of various irregular pores could be constructed, and the pore size, porosity, and specific surface area of porous scaffolds could be controlled by adjusting the deformation, distribution, volume of the hexahedral elements, and the structure of the TPMS pore units, which provides a feasible method for the design and regulation of heterogeneous porous scaffolds.

Aiming at the mechanization and automation of cleaning the hardening on the wall of the cement silo, a silo cleaning robot is designed. The kinematics and dynamics mathematical models of the cleaning robot are established respectively. With the 12000mm diameter silo as the cleaning object, the dynamics model is constructed with virtual prototype. There is an analysis of the relationship between the angular velocity and angular acceleration of the mechanical arm, and the relationship between the thrust of the cylinder over time were analyzed. The results show that the calculation results of the mathematical model and the simulation model are close, the change trend is consistent, and the movement is stable and meets the design requirements, which verifies the correctness of the mathematical model. The research results provide a theoretical basis for the next step of control system design and strength analysis. This silo cleaning robot solution can be extended to the cleaning construction of other silos such as coal bunkers, granaries and ore silo.

According to the geometrical characteristics of cylindricity error, a method for cylindricity error evaluation using Geometry Optimization Searching Algorithm (GOSA) has been presented. The optimization method and linearization method and uniform sampling could not adopt in the algorithm. The principle of the algorithm is that a hexagon are collocated based on the reference points in the starting and the end measured section respectively, the radius value of all the measured points are calculated by the line between the vertexes of the hexagon in the starting and the end measured section as the ideal axes, the cylindricity error value of corresponding evaluation method (include minimum zone cylinder method (MZC), minimum circumscribed cylinder method (MCC) and maximum inscribed cylinder method (MIC)) are obtained according to compare, judgment and arranged hexagon repeatedly. The principle and step of using the algorithm to solve the cylindricity error is detailed described and the mathematical formula and program flowchart are given. The experimental results show that the cylindricity error can be evaluated effectively and exactly using this algorithm.

A new method for evaluating roundness error using polar measurement data, which named as polar mesh searching algorithm (PMSA), has been presented in this paper. The principle of the algorithm was that series of polar-coordinate mesh points were collocated around the periphery of the least square circle according to certain rule, the radius of all the measured points were calculated by regarding each mesh point as the ideal center, and the roundness error from minimum circumscribed circle method, maximum inscribed circle method and minimum zone circle method were achieved accurately through comparing these radius. In the paper, the process and steps using the PMSA to solve the roundness error were described in detail and the mathematical formula and program flowchart were given. The simulation and experiment results show that roundness error can be evaluated effectually and accurately by this algorithm.

The integration of multi-view data in the acquisition of complex surface is researched by using the CMM (coordinate measuring machine) and the laser tracking scanning system. A multi-view data integration method based on the auxiliary reference plane is presented. With the precise auxiliary reference plane, the data measured by the different measuring devices and measuring views are aligned. The problems of low-efficient and low-accuracy in the data fusion of complex surface during the reverse engineering are solved. Meanwhile, the advantages of the different measuring devices and measuring methods are developed. This method has been applied to the reverse engineering development for a motorcycle cover model. The practical result shows that this new method is feasible and efficient.Copyright © 2009 by ASME