In this paper, a novel method to construct a versatile gripper which can grasp various sizes and shapes of objects is proposed. The design and construction of this gripper is based on a paper folding technique called `modular origami' This particular type of origami is constructed from multiple modules which can transform its shape by rotation. The gripper is actuated by a single motor using a linkage mechanism. The grasping part of this gripper is made of paper, thus it provides sufficient compliance to bend itself and create multiple contact points around objects with different shapes. This gripper can be used in two modes: force grasping and cage grasping. The proposed gripper was tested on objects with various shapes, weights and sizes. Furthermore, how the property of the paper affects the performance of the gripper was also tested. The thickness of the gripper material affects the compliance of the gripper and the range of sizes of objects which can be successfully gripped.

This research aims to study the grasping torque profile of the helical climbing robot on the cylindrical pole with constant radius. The modular snake robot is formed into a helical shape which can be described by various parameters such as the helical pitch angle, the radius and the pitch distance. The torque in each axis of rotation is affected by the helical pitch angle parameter. Five grasping configurations with different helical pitch angle were tested on the 18 degree of freedoms, 7 modules wheeled snake robot. The experimental result showed that the torque around yaw axis transferred to the pitch axis when the helical pitch angle was increasing. The profile of torque magnitude along the robot's body resulted in parabolic shape due to the unbalanced grasping force of the discrete points of contact between the robot and the pole.

In this paper, an approach for behavior imitation using visual information was introduced. The imitation process is done by a self organizing neural network module. From several demonstrations of task operation, a vision system captures movement of the demonstrator mobile robot and associated objects in an operation field. Then, the movement features are extracted to present to an imitation engine. Finally, skill or decision policy from teacher's demonstration is extracted and embedded into a self organizing neural network without explicit external supervisory signals. A simple action selection algorithm for choosing action from learned network is proposed. The algorithm was implemented and tested on a simulated robot and a real mobile robot to imitate two simple robot soccer behaviors: approaching the target and obstacle avoidance. Furthermore, the concept of similarity measure is introduced to evaluate imitation performance from the demonstrator

The objective of this paper is to analyze the mechanics of object pulling by more than one robot using flexible tools such as rope. The concept of nonprehensile pulling where an object is not completely tied by a rope such that an object can roll or slide along the rope is the main focus of this study. The necessary condition for a stable nonprehensile pulling is defined. The mechanics of nonprehensile pulling is used to define the set of feasible motion directions of the object. This set of feasible motion directions of the object is then used for planning the coordination between two robots such that the task of object transportation can be achieved. The proposed analysis can also be extended for multiple objects transportation. This study provides a necessary basis required in developing an algorithm for a group of robots to autonomously cooperate such that the pulled object can be positioned and oriented in the 2D space.

Multiple mobile robots are a practical platform for realizing the concept of distributed manipulation. New approach for manipulating large number of objects using distributive actuators or agent has been suggested. Multiple mobile robots provide the ability to conduct actions simultaneously from various locations and directions. Using two mobile robots and flexible tool such as a piece of string or rope, a large number of objects that are placed at sparse locations can be sorted and grouped by single action. The Voronoi separation algorithm is proposed as a path generation method for preplanning cooperative actions of multiple robots. The sorting task is conducted on-line using fuzzy logic controller with preplanned subgoals. The proposed control framework was verified by an experiment using two autonomous mobile robots with a flexible tool attachment of fixed length.

Passivity concept has been using as a framework to solve the stability problem in bilateral control of telemanipulation. However, the conservative selection of dissipating element applied to maintain system stability in network communication leads the system to imperfect operation or losing transparency. In this paper, we proposed a new control scheme to adapt characteristic impedance with time. The proposed method is not only presented in simple form, but also effectively make the operation transparent teleoperation. We verified the validity of our method by teleoperation simulations with constant and variable time delay.

Kinematic conditioning of robot manipulators is the problem where small motions in Cartesian space cause excessive joint velocities. This problem is significant in teleoperation. Haptic feedback provides the bi-directional flow of information which allows the operator to control the telerobot interactively. Haptic feedback of kinematic conditioning is proposed as a new approach to achieve better performance in telerobotic control near kinematic singularities. Four different singularity force feedback methods are defined and studied. Experimental results with a force feedback master and simulated slave system show that teleoperation performance near singular configurations was affected and improved by using singularity force feedback.

A combined university/industry team has developed a prototype system for handling protein crystals aboard the space station. This system uses a miniature direct drive robot, CCD television cameras, and a client-server computing system using Internet protocols to support the capture of protein crystals from aqueous growth solutions. The system was demonstrated between Huntsville AL. and Seattle WA. An operator in Huntsville controlled the mini robot by invoking predefined relative and absolute macro files. The operators observed results using video images sent through the Internet link using Cu-SeeMe video conferencing software. In 3 of 4 trials, the operators successfully captured 0.5 mm simulated protein crystals into a glass capillary. The system is a promising start for the development of a space-station based remote protein crystal analysis facility.