A Review of Infrared Thermography for Delamination Detection on Infrastructures and Buildings

This paper provides a comprehensive review on the use of infrared thermography to detect delamination on infrastructures and buildings. Approximately 200 pieces of relevant literature were evaluated, and their findings were summarized. The factors affecting the accuracy and detectability of infrared thermography were consolidated and discussed. Necessary measures to effectively capture latent defects at the early stage of delamination before crack formation were investigated. The results of this study could be used as the benchmarks for setting standardized testing criteria as well as for comparison of results for future works on the use of infrared thermography for detection of delamination on infrastructures and buildings.

Dual-Arm Coordinated Control Strategy Based on Modified Sliding Mode Impedance Controller

To meet the high-accuracy position/force control requirements of dual-arm robots for handling a target object, a control algorithm for dual-arm robots based on the modified sliding mode impedance controller MSMIC(tanh) is proposed. First, the combinative kinematics equation of the dual-arm robots and the unified dynamics model combining the manipulated object is established. Second, according to the impedance control motion model for the object, the desired joint angular accelerations of the manipulators are obtained, and the sliding mode controller based on the hyperbolic tangent function as the switch function is introduced to design the coordinated control strategy for dual-arm robots. The stability and convergence of the designed controller are proved according to the Lyapunov function theory. Finally, the operation tasks of the coordinated transport the target object for dual-arm robots are carried out in the simulated experiment environment. Simulation results show that the proposed control scheme can stably output the required internal force and achieve a high-precision trajectory tracking effect while reducing the periodic torque and joint chattering amplitude generated in the conventional sliding mode control algorithm.

Does Target Object Processing Affect Reaction Times in Simple Detection Spatial Cueing Tasks?

The current study tested the effect of varying target type and target set size during simple detection versions of Posner's exogenous spatial cueing task. The four target conditions consisted of a single letter, a single number, one of four possible letters, or one of four possible numbers. Responses were faster for numbers than for letters, but only when the cue-target lag was short, the target set included more than one potential number, and the cue and target appeared in different locations. These findings suggest that even during detection tasks, responses are influenced by the object features of the target. Methodological implications for spatial cueing studies and other types of visual perception research were discussed.