Visual Measurement and Calibration of Geometric Errors of Rotating Axes for Five-axis Platform

In this paper, a method for identifying and decoupling geometric errors of rotation axes using vision measurement is proposed. Based on screw theory and exponential product formula, identification equations of position-dependent geometric errors (PDGEs) and position-independent geometric errors (PIGEs) of the rotation axes are established. The mapping relationships between the error twist and geometric errors are established. The error model provides the coupling mechanism of PDGEs and PIGEs. Furthermore, a progressive decoupling method is proposed to separate PDGEs and PIGEs without additional assumptions. The pose parameters, required for solving the identification equations, are obtained by visual measurement. Then, the error terms of PIGEs and PDGEs are determined. Lastly, the error calibration of the rotation axes is investigated, thus providing an average rotary table orientation error reduction of 28.1% compared to the situation before calibration.

Deep learning-based virtual cytokeratin staining of gastric carcinomas to measure tumor–stroma ratio

The tumor–stroma ratio (TSR) determined by pathologists is subject to intra- and inter-observer variability. We aimed to develop a computational quantification method of TSR using deep learning-based virtual cytokeratin staining algorithms. Patients with 373 advanced (stage III [n = 171] and IV [n = 202]) gastric cancers were analyzed for TSR. Moderate agreement was observed, with a kappa value of 0.623, between deep learning metrics (dTSR) and visual measurement by pathologists (vTSR) and the area under the curve of receiver operating characteristic of 0.907. Moreover, dTSR was significantly associated with the overall survival of the patients (P = 0.0024). In conclusion, we developed a virtual cytokeratin staining and deep learning-based TSR measurement, which may aid in the diagnosis of TSR in gastric cancer.

Robot Floor-Tiling Control Method Based on Finite-State Machine and Visual Measurement in Limited FOV

In recent years, accelerative aging society is meeting the short supply of young and middle-aged labor. Particularly, most young people are reluctant to work in the construction industry, which has caused the labor cost of floor tiling to rise year by year. In addition, floor tiling requires workers to continuously bend over or lean over to work, which greatly jeopardizes the physical health of them. Therefore, advanced technology applied in floor tiling is highly demanded to replace the traditional manual method. On the context, the automatic method of floor tiling may promote the transformation and upgrading of the industry. Although a few robots for floor tiling have been developed, the automation of existing systems is still at a low level. This paper proposes a robot floor-tiling control strategy based on visual measurement feedback and finite-state machine, in which the calculation of tile position information in limited field of vision is obtained by an improved Canny edge detection and a Hough linear transformation. Moreover, an algorithm for complementing tile position information based on visual measurement is proposed, and the quality of tile laying is evaluated online. To evaluate the effect of the proposed control strategy, the experimental verifications are given. The experimental results indicate that the proposed method can complete the automatic floor tiling with high accuracy.