This paper proposes a simple extrinsic calibration method for a multi-sensor system which consists of six image cameras and a 16-channel 3D LiDAR sensor using a planar chessboard. The six cameras are mounted on a specially designed hexagonal plate to capture omnidirectional images and the LiDAR sensor is mounted on the top of the plates to capture 3D points in 360 degrees. Considering each camera–LiDAR combination as an independent multi-sensor unit, the rotation and translation between the two sensor coordinates are calibrated. The 2D chessboard corners in the camera image are reprojected into 3D space to fit to a 3D plane with respect to the camera coordinate system. The corresponding 3D point data that scan the chessboard are used to fit to another 3D plane with respect to the LiDAR coordinate system. The rotation matrix is calculated by aligning normal vectors of the corresponding planes. In addition, an arbitrary point on the 3D camera plane is projected to a 3D point on the LiDAR plane, and the distance between the two points are iteratively minimized to estimate the translation matrix. At least three or more planes are used to find accurate external parameters between the coordinate systems. Finally, the estimated transformation is refined using the distance between all chessboard 3D points and the LiDAR plane. In the experiments, quantitative error analysis is done using a simulation tool and real test sequences are also used for calibration consistency analysis.

Although video content includes many advantages over audio content in terms of information delivery, the latter is being continuously released into the market. Additionally, audio content is being consumed in repetitive daily work situations that require the continuous use of eyesight because such content transmits information by only using auditory stimuli. Therefore, this study examined how listening to audio content while performing simple repetitive tasks can affect the performance and perception of such tasks. Based on the findings, although the audio content type decreased the participants’ performance of the primary task, the difference was not statistically significant. Contrary to the effect on performance, the audio content lowered the fatigue and boredom of the primary task, while increasing satisfaction, enjoyment, and immersion. In particular, music, entertainment speech, and information speech had a significant effect on the participants’ work cognition, whereas autonomous sensory meridian response (ASMR) had no statistically significant effect.