International Journal of Intelligent Machines and Robotics (5 papers in press)
CONTACT POINTS DETERMINATION AND VALIDATION FOR GRASPING OF DIFFERENT OBJECTS BY A FOUR-FINGER ROBOTIC HAND
by Eram Neha, Mohd. Suhaib, Sudipto Mukherjee
Abstract: Grasping and manipulation of objects with the multi-fingered robotic hand is required in order to replace human hands in performing various tasks. It is desirable to analyse a robotic hand in comparison with the human hand in terms of stability and various grasp properties. Therefore, in order to attain a stable grasp, the contact points and the grip configuration must be selected in accordance with the grasp stability. In this paper, grasp analysis of the four-fingered tendon actuated robotic hand is carried out. The hand is simulated to grasp different objects in order to determine the contact points of the fingertips on the surface of these objects. Simulation of the hand is done to check the grasp capabilities prior to experimentation while grasping different objects and obtain the contact points for the same. MATLAB SimMechanics tool is used to perform the 3D visualization of the robotic hand where the fingers are controlled in order to grasp objects at the contact points. The obtained contact points are validated using the kinematics and geometric collision detection. These contact points are further utilized to determine the amount of weight required by the tendon to produce the flexion motion in order to grasp the object at the contact points.
Keywords: Contact Points; Tip Prehension; Flexion motion; tendon actuated; SimMechanics.
Workspace Optimization of 3R Manipulator- A Multi-objective Approach
by Sumanta Panda, D. Mishra, Bibhuti Bhushan Biswal
Abstract: Optimum workspace with a compact manipulator is one of the decisive factors in the optimum design of robot manipulator. In this article the workspace volume of a 3R robot manipulator has been optimized on a multi-objective basis using Differential Evolution (DE) algorithm. An additional objective of this study is to synthesize the total void cross section area. The proposed algorithm is tested on four diverse examples. The result obtained are compared with the results available in the literature. The key design kinematic parameters are identified through a statistical analysis. To ensure the practical applicability the proposed design approach has been tested on two industrial manipulators viz. KUKA KR-30 and Mitsubishi MRP-700A. Furthermore, it has been found that the predicted results of the simulation are in excellent agreement with the actual values.
Keywords: Optimization; Differential Evolution; Manipulator; Workspace volume.CPU time.
Annotation of Medical Images using Integral images and Gabor coefficients
by Hedieh Sajedi
Abstract: - Image annotation is one of the aspects of automatic classification algorithms. In this paper, we propose a learning-based algorithm for automatic medical image annotation based on local appearance cues by using Integral images, Gabor transforms, AdaBoost and Support Vector Machine (SVM) classification algorithm. The algorithm starts with a number of landmarks. By landmarks, we generate special sub-patches and extract features using Gabor transforms. In fact, Gabor filter is applied to Integral image. The value at any point (x, y) in Integral image is just the sum of all the pixels above and to the left of (x, y). AdaBoost in most cases can make a decision about the instances at this stage. To solve the misclassified cases, we combine similar classes and employ SVM/ AdaBoost to recognize close instances. This approach is evaluated on large-scale radiograph images and several experiments have been done. At first, we specify five classes with the most number of images in ImageCLEF2008. Then, the proposed method is used for position identification task. Three parts of the anatomy, skull, chest, and cervical spine are classified by the highest accuracy in this method. At the end, our approach achieved the acceptable accuracies for multiclass radiograph annotation task, when compared to other algorithms. Another advantage of our method is the small length of feature vector, which reduces the time of annotation. We obtain the accuracy of 95% for multiclass radiograph annotation and >99% for position identification task.
Keywords: Medical image annotation; Landmark; Integral image; Gabor transform; AdaBoost Algorithm; Support Vector Machine.
DESIGN AND DEVELOPMENT FOR GENERATION OF REAL OBJECT VIRTUAL 3D MODEL USING LASER SCANNING TECHNOLOGY
by Makarand Jadhav, Yogesh Durgude, Virendra Umaje
Abstract: Technology has evolved to generate or recreate anything that human brain is capable of dreaming. rnMany centuries old artefact was found in museum. A damaged and a recreated artefact both were kept adjacent to each other. The effort to recreate the replica of the model was a biggest challenge. This paper proposes to develop a real-time stationary 3-D scanning system. The system scans a real object to translate into a virtual object. The associated data is utilized to build 3-D digital model. A LASER unit operating at 650 nm with tilting angle of 600 is spaced 15 cm from web-cam. A triangulation technique helps to capture images in the range of 26 cm. Further, segmentation and contours estimate point cloud of the object. It is observed that developed model has an accuracy of 92-96 % and relative error of 2 - 8 %. The model is validated on conical flask, tiffion box and coffee mug objects. 3D scanners can be used in applications such as 3-D printing, restore and recreate archaeological artefacts and in entertainment industry. rn
Keywords: 3-D scanner; 3-D reconstruction;computer vision; LASER; triangulation; 3-D printing.
Design and structural analysis of a novel robot foot with 3-UPS/S parallel mechanism
by Hongmei Zhang, Fuji Wang, Jianwei Ma, Youyang Zou
Abstract: The foot plays an important role in performance of the legged robot. However, the foot which have been designed has various disadvantages which does not meet a series of robot requirements such as heavy load, damping and flexibility. So, a foot with 3-UPS/Sparallel mechanism is proposed in this paper, and it has various functions to achieve its goals. And a detailed discussion about a correlation between foot requirements and structure, mobility characteristics and geometrical constraints is presented. Then, based on the Bekker pressure-sinkage theory, foot-terrain interaction model is built and the soil deformation can be calculated to judge foot stable possibility. Finally, the foot dimensions are carried out, and then corresponding results are calculated to check working state in different terrains. The above analyses illustrate that the foot with 3-UPS/S parallel mechanism has good features, which validates the feasibility of applying this mechanism as a foot.
Keywords: Foot; parallel mechanism; stability analysis; structural analysis; legged robot.