Current Issue : January - March Volume : 2021 Issue Number : 1 Articles : 5 Articles
Three-dimensional (3D) triangulation based on active binocular vision has increasing\namounts of applications in computer vision and robotics. An active binocular vision system\nwith non-fixed cameras needs to calibrate the stereo extrinsic parameters online to perform 3D\ntriangulation. However, the accuracy of stereo extrinsic parameters and disparity have a significant\nimpact on 3D triangulation precision. We propose a novel eye gaze based 3D triangulation\nmethod that does not use stereo extrinsic parameters directly in order to reduce the impact.\nInstead, we drive both cameras to gaze at a 3D spatial point P at the optical center through visual\nservoing. Subsequently, we can obtain the 3D coordinates of P through the intersection of the two\noptical axes of both cameras. We have performed experiments to compare with previous disparity\nbased work, named the integrated two-pose calibration (ITPC) method, using our robotic bionic eyes.\nThe experiments show that our method achieves comparable results with ITPC....
The motion analysis of two-finger tip pinching using the thumb and index finger provides crucial data for designing the motion\nmechanism of electric prosthetic hands. The purpose of this study is to determine the joints that have high mobility\nduring two-finger tip pinching by measuring the flexion angle of each joint. Ten Japanese men with normal hand were selected.\nCT images were obtained while the hands adopted the following four postures: a basic posture not pinching a cylinder, and\nthree postures pinching wooden cylinders with different diameters (2, 10, and 30 mm). Three-dimensional bone models of the\nthumb and index finger were created using the CT images and used to measure the flexion angles of the joints. The flexion\nangles of the proximal interphalangeal and metacarpophalangeal joints of the index finger significantly decreased as the\ndiameter of the cylinder increased. However, even when the diameter of the cylinder changed, the flexion angle of the distal\ninterphalangeal joint of the index finger, and the flexion and rotation angles of all of the thumb joints did not change. When\npinching objects of different sizes with a two-finger tip pinch, the posture of the thumb is fixed, and only the posture of the\nindex finger changes. When designing the two-finger tip pinch motion for an electric prosthetic hand, it is sufficient to drive the\njoints of the index finger only....
Na........................
Among many nano materials and chemical materials, zinc oxide nanomaterials have attracted researchersâ?? interest because of their\nhigh efficiency, low cost, easy preparation, and variable morphology. The purpose of this study is to explore the fabrication and\nconductive process of nano ZnO varistors under the simulation of an animation plane form. In this study, the chemical vapor\ndeposition method was used to prepare nano ZnO. Then, ZnO nanomaterials were mixed with deionized water to form a\nsuspension. Under the action of a micromechanical stirrer, impurities were removed by heat treatment, and then different amount\nof water was added to obtain a nano ZnO electrode. The conductive process and electrochemical properties of the nano ZnO\nelectrode were investigated and analyzed. The results show that the pressure ratio of the varistor increases obviously after adding\nnano ZnO. In the range of 0â??30%, the pressure ratio of the ZnO varistor increases with the increase in nano ZnO content. When w\n(nano ZnO) is 30%, the voltage ratio reaches 1.149 and the oxidation peak current ratio of LD decreases by 6%. Therefore, it is\nconcluded that the electrode of nano ZnO varistor valve sheets maintains good stability for a LD conductivity detection process. It\nalso plays an important role in electrochemical research....
Aiming at the problem that the stability of the quadruped robot is decreased as its leg momentum is too high, a stable balance\nadjustment structure of the quadruped robot based on the bionic lateral swing posture is proposed. First, the leg structure of the\nquadruped robot is improved and designed by using the mechanism of the lateral swing posture of the leg of the hoof animal.\nThen, the D-H method is used to construct the corresponding leg kinematics model and determine the generalized coordinates of\nthe leg joints in the lateral swing posture. The torque expression of the quadruped robot when it is tilted is established. Based on\nthe differential equation of momentum of the hip joint and its static stability analysis, the static stability conditions in the upright\nposture and the bionic lateral swing posture are given. Finally, the experimental simulation and comparative analysis of the\nupright posture and the lateral swing posture of the quadruped robot are proposed by using the Adams virtual prototype\ntechnology. The simulation results show that as the angle of lateral swing increases, the peak value of the positive flip torque of the\nquadruped robot body increases accordingly, while the degree of tilt decreases accordingly, which shows that the bionic lateral\nswing posture of the quadruped robot has higher static stability than the traditional upright posture. This research provides a\ntechnical reference for the design and optimization of the offline continuous gait of the robot and the improvement of stability....
Loading....