Generation of human-like gesture is an important factor for human- robot communication. However, Generation of smooth gesture by the robot manipulator is difficult because the difference between the human arm kinematics and robot arm kinematics is amplified in their appearances. In this paper, we propose the new robot gesture generation approach based on appearance from the user viewpoint.
This paper discusses the controllability and the reorientation planning of 3D free-flying Linkage robots. By exepmlifying various types of the robot, we showed that the minimal degree of freedom could be two so that the base orientation can be controlled as well as the arm configuration of the robot. Then we proposed a new reorientation planning method. This method requires only two joints of moving, and is derived based on the piece together of three closed paths in planar configuration space. Its efficacies are showed by a couple of simulation results, such as fast convergence of computation, movement efficiency and availability to any type of robots, compared to other proposed methods.
The wheeled robot's ability is one of the most important factors which is influential with efficiency of achieving tasks by robots. Demands for mobile robots change where environment and purpose does, therefore various mechanisms of mobile robots are proposed. However, there is no standard or general guideline of designing moving mechanisms. In this paper, we classify and denote characteristics of moving mechanisms systematically, and indicate the guideline when we design them. Especially we describe omnidirectional robots and irregular terrain robots.
This paper proposes a control strategy of 3D free-flying linkage robot sytems, which can make the base orientation and the arm configuration simultaneously converge to desired states. Mainly since its constraint is non-Chaplygin, the feedback control of 3D free-flying robot had been difficult to accomplish, compared to the case of planar robots. The proposed controller time-invariantly generates smooth Lie bracket motions. The keys of the strategy are (I) selecting two of the system's DOF, (II) coordinate transforming the configuration variables to Fourier basis coordinate form, (III) defining the system limit orientation and its approximation form. This can be surely applicable to the systems with more than 3DOF. A couple of simulation results showed its efficacy and practicability.
Precise measurements of geometry should accompany robotic equipments in operating rooms if their advantages are further pursued. For deforming organs including a liver, intraoperative geometric measurements play an essential role in computer surgery in addition to pre-operative geometric information from CT, MRI and so on. We developed a laser-pointing endoscope using an optical galvano scanner and a 955 [fps] high-speed camera. The laser-pointing endoscope system acquires and visualizes the shape of the area of interest in a flash of time. Applications of the system also include the touch-screen interface for non-master-slave operation of surgical robots, where the 3D coordinates of the touched point on screen are measured by the system and guide a robot. Results of in-vivo experiments on a liver of pig verify the effectiveness of the proposed system.
A bilateral teleoperation experiment with Engineering Test Satellite No.VII (ETS-VII) was conducted on November 22, 1999. Round-trip time for communication between the NASDA ground station and ETS-VII was approximately six to seven seconds. We constructed a bilateral teleoperator that is stable even under such a long time delay. Several experiments, such as slope tracing task and peg-in-hole task, were carried out. Task performance was compared between bilateral mode and unilateral mode with force telemetry data visually displayed on a screen. All tasks were possible by bilateral control without any visual information. Experimental results showed that kinesthetic force feedback to the operator is helpful even under such long time delay and improves the performance of the task.
In this paper, we consider an optimization of grasping by using a required external force set. By using the set, we can not only deal with whatever a desired grasp is, such as force-closure or equilibrium grasp, but also evaluate the magnitude of resultant force which we can apply to the object. By using the set, we define an optimization problem from the viewpoint of decreasing the work of contact forces, and show that we can solve the problem by using a branch-and-bound method. Lastly we present some numerical simulations for verifying our approach.
In this paper, we discuss end-effector acceleration manipulability of flexible manipulators. We propose a nonstretch flexible beam model which is better to express real flexible beams than Euler-Bernoulli or Timoshenko beam. Based on this model, we have shown that a flexible beam has only one direction to transfer acceleration from driving force/torque on its proximal end. This is an intermediate characteristic between rigid body and elastic body. We have also found that conventional flexible' manipulators (with point joints) have no direct relation between proximal driving force/torque and distal acceleration. Then we have discussed a new construction with rigid flanges and found that the flexible manipulators with rigid flanges have a direct relation between proximal driving torque and distal acceleration in only one direction. We verified above numerical results by some experiments.