35740553
Real-time vision-based contour following with laser pointer
This article addresses the visual servoing of a rigid robotic manipulator under fixed camera configuration. A laser pointer is mounted on the end-effector of a robot whose orientation can be controlled by automatic visual feedback. The control goal is to drive the laser spot to follow a visually determined planar contour by using a single-camera vision system. In this research, image-based control approach is proposed to achieve "precise" positioning in the absence of measurement noise. With this system, one can achieve automatic planar contour following using approximately calibrated single-camera vision. The control strategy is successfully validated in a real-time PC-based experimental system by performing experiments on arbitrary contour following.
34708650
Exponentially stable positioning of a rigid robot using stereo vision
This article addresses the visual servoing of a rigid robotic manipulator under fixed camera configuration. The control goal is to move the robot end-effector to a visually determined target position by using a vision system equipped with two fixed cameras. A general image-based controller is proposed to achieve "precise" positioning in the absence of measurement noise. Based on the "epipolar constraint", we have shown that the overall closed-loop system using redundant image features, is exponentially stable provided that the camera model imprecision is small.
1148386
Refining the sonic flashlight for interventional procedures
Ultrasound (US) is often used in interventional procedures such as accessing blood vessels, performing biopsies, and placing drains. The sonic flashlight (SF) is a handheld device that uses a mirror to reflect a real-time US image into the body, making that body part appear translucent. The latest generation handheld SF has been improved to the point where it can be applied to procedures involving fine structures such as vasculature and small tumors. We have dramatically decreased the size, weight, and display lag-time, while increasing resolution. With these improvements, the operator can now clearly visualize and discriminate between small structures. We believe that this version of the SF is ready for clinical trials.