Akinori Sasaki

Driving Electric Car by Using EMG Interface

This paper proposes a useful method driving the electric car by using EMG interface, which is used as living body interface. The EMG signal can be measured from all the people easily, even physically handicapped people, elderly and so on. The EMG signals are measured from both hand palms and neck using a simple electrode. In our interface, the effective frequency band of EMG signal is extracted to drive the electric car effectively. The extracted signal is converted to binary signal which drives differential motor. In the experiments that driving the electric car by using the proposed EMG interface, we used the SD method to evaluate of operation feeling and riding comfort. As a result, it is shown that the effective frequency band gives an influence on operation feeling and riding comfort

Walker with hand haptic interface for spatial recognition

This paper presents a user-friendly hand force feedback system to recognize surrounding obstacles around the elderly to making walking safer. The system is implemented on a joystick mounted on a walker. The user is able to recognize the surrounding spatial information from the repulsive force generated as feedback on the joystick. The system is based on the generation of a virtual potential field that corresponds to the distance and direction to the obstacle is employed. Through the experimental results, it is found that the practice time of the user to learn basic operation of the system is sufficiently short. Furthermore, the user feels the sense of security while recognizing the surrounding information through the hand force feedback

New Stage Structure of Iodine Doped Pentacene Film (II)

Abstract In pure pentacene film and iodine doped pentacene film, X-ray and electric conductivity measurements were performed. It was found from X-ray diffraction data that the iodine doped pentacene possess the stage-2 structure in addition to the stage-1 structure. The c axis lattice constant of the stage-2 structure, which is the length of the interval between the layers, was determined to be 33.2 Å. Moreover, electric conductivity was measured in pentacene doped with iodine at the various doping temperatures T d. This result was compared with the results obtained from X-ray diffraction data.

Stability of swarm robot based on local forces of local swarms

This paper proposes a control algorithm for a robotic swarm based on the center of gravity of the local swarm. In order to be compatible with maintaining a high stability of the whole swarm and advancing to the goal, virtual forces; local forces and an advancing force which are produced by the algorithm, are applied to multiple autonomous mobile robots. Local forces such as an attraction and a repulsion, are applied to each robot for increasing the stability of the local swarm. Overlapping each local swarm partially increases the stability of the whole swarm. The advancing force is applied to each robot for advancing to the goal while maintaining the stability of the local swarm. Since obstacles which prevent the robot advancing are considered as a disturbance from the viewpoint of the stability of the whole swarm, an effectiveness of the algorithm in obstacle space is evaluated using a dynamics simulation. As a result, it is found that the algorithm is able to maintain the high stability of the whole swarm advancing to the goal.

New stage structure of iodine doped pentacene film

The iodine doped pentacene films have been prepared using the two bulb method. The X-ray diffraction studies show that the iodine doped pentacene possess the so-called second stage structure in addition to the first stage structure. The typical doping temperature to obtain the second stage structure is 5.2°C. From this result, the c axis lattice constant of the second stage structure, which is the length in the interval in the layer, was determined to be 33.2 A.

Cooperative interaction of walking human and distributed robot maintaining stability of swarm

This paper proposes a method of cooperative interaction that a human and distributed robots move cooperatively so as to maintain the swarm situation that robots surround the moving human. This paper is concerned with the control for maintaining the high stability of the swarm, and proposes a control algorithm for the robotic swarm in obstacle or slope space. The proposed algorithm for overcoming above problems is based on the center of gravity of the local swarm which attracts the robot to it, and is applied to the omni-directional mobile robots. It is confirmed that the effectiveness about maintaing the stability of the swarm through simulations using ODE (Open Dynamics Engine).

Hand Force Feedback System to Recognize Surrounding Objects for Safe Walking

This paper presents a user-friendly hand force feedback system to recognize surrounding obstacles around the elderly to making walking safer. The system is implemented on a joystick mounted on a walker. The user is able to recognize the surrounding spatial information from the repulsive force generated as feedback on the joystick. The system is based on the generation of a virtual potential field that corresponds to the distance and direction to the obstacle is employed. Through the experimental results, it is found that the practice time of the user to learn basic operation of the system is sufficiently short. Furthermore, the user feels the sense of security while recognizing the surrounding information through the hand force feedback.

Cooperative movement of human and swarm robot maintaining stability of swarm

This paper proposes a method that a human and a swarm robot move cooperatively so as to maintain the swarm situation that the swarm robot surround the moving human. This paper is concerned with the control for maintaining the high stability of the swarm, and proposes a control algorithm for the robotic swarm in obstacle space. In this paper, the robotic swarm which includes whole robots is defined as a whole swarm. In addition, each robot with neighboring robots forms a local swarm that overlapped the other ones partially, so a robot can belong to some local swarms. The proposed algorithm for overcoming above problems is based on the center of gravity of the local swarm which attracts the robot of it, and is applied to the omni-directional mobile robots. It is confirmed that the effectiveness about maintaing the stability of the swarm through simulations using ODE (open dynamics engine).

Distinction of finger operation for myoelectric prosthetic hand on the basis of surface EMG

In this paper, recognition of finger operation via surface EMG is discussed. Finger operation was distinguished into six kinds of motion, and identification of the finger operation was performed using two types of identifiers. One of the identifier is on the basis of combined feedforward neural networks, and the other identifier is on the basis of self-organizing map. A finger operation is carried out in approximately 0.5 seconds for each motion. The recognition accuracy of each identifier was examined for the finger operation, and compared. Finally, the robotic hand for a myoelectric prosthetic hand was controlled according to the recognition result of the finger operation.

Investigation of human motion under conditions with sensory feedbacks restricted in yo-yo control

Getting accustomed to and enjoying sports or such physical activity is desirable for people to achieve high quality of life. Whereas learning various motions in such sports requires long time because of the complexity of the motions themselves or ambiguity of verbal instructions. Therefore it is worth struggling to sophisticate such instructions from the perspective of human motion analysis and control engineering. This paper describes an investigation of human motion in yo-yo control. For separating effects of visual and force sensory feedbacks, human motion in yo-yo control is observed under conditions 1) with no sensory feedback restricted, 2) with only visual sensory feedback restricted, and 3) with only force feedback restricted.