Stereoscopic imaging camera with simultaneous vergence and focus control

We present the development of a parallel-axis stereoscopic imaging camera (PASIC) for teleoperation and depth measurement. To reduce the vergence focus decoupling problem, which could cause cybersickness, we design mechanism to control the vergence and the focus of the camera simultaneously. We analyze the relationship between parallel and orthogonal motions of the camera lens system with respect to the image plane. Under the condition that the lateral disparity in stereo images remains constant, the parallel motion causing vergence and the vertical motion causing focus show linear relationship. The camera is calibrated to a reference distance, and the depth to an object is computed by a triangulation technique and a calibration lookup table. We analyze the accuracy of depth measurement with the consideration of radial distortion. Then the calibration table is refined accordingly.