Stable biped locomotion is realized under cooperation between motions on frontal plane and on sagittal plane. Therefore, regulating motion on frontal plane has much effect on stabilizing locomotion. However, few discussions about motion control on frontal plane have been taking place. We propose cooperative control that regulates motion on frontal plane so that the cooperation may be kept. In the method, motion on frontal plane is approximated with an inverted pendulum model, and interference of motion on sagittal plane with that on frontal plane is regarded as external force. Then, compliance controller on frontal plane is designed to achieve cooperative control objective that is set up based on ZMP criterion. The compliance controller and the rhythm-correction feedback control system proposed by S. Kawaji et al. [13, 14] are integrated into cooperative biped locomotion control system. The effectiveness of the system in stabilizing locomotion was verified through a locomotion simulation.
This paper presents a method for detecting invariant task structures that are commonly shared by the human operator and the autonomous robot in a VR-based (i.e., virtual reality based) mobile robot teleoperation system. We call such a property of having common structures as task-morphology, and we discuss how this property functions well to establish the naturalistic task sharing between the two who have different perception-acting capabilities. For this purpose, we analyze their continuous task performance and segment them into some qualitatively different phases using Adaptive Resonance Theory (ART).
Avoidance plannings of robots considering human emotions are discussed in this paper. When a robot avoids a human in the same workspace, two conditions should be satisfied in the avoidance motion. That is, the robot should keep desirable distance to the human and the motion trajectory should have smooth profiles, which gives human good impressions. From this point of view, a simple control rule of a robot in which the robot follows human motion keeping a desirable distance (following distance) is adopted first. Relation between the following distance and task speed of the robot, and human emotion is psychologically evaluated using a two dimensional robot. Next, an improved control method in which the results of the psychological evaluation are used for determining the following distance is considered using fuzzy inference. The effectiveness of the control method is experimentally clarified.
Human-centered design and control are vital for the human-machine system. Especially, the estimation of human's intention will become a key technology for the cooperation with human and the physical assistance by robotic machine. Surely, we are regulating well the mechanical impedance (inertia, viscosity and stiffness) of our arm in accordance with the task. Therefore, it is supposed that the adjustment of impedance reflects the operational intention. In this study, the positioning task with different accuracy is treated. And, the hand-viscosity is estimated on-line during positioning by the neural network whose input is the electromyogram (EMG). Using this information, the dynamics of machine is controlled so as to generate adequately assistant motion. In the experiments, the effectiveness of the proposed operational assistance system is confirmed from the viewpoint of maneuverabilities and workload.
An ankle orthosis is prescribed for the persons who have the movement disorders caused by the paralyzed ankle. The most important purpose of the ankle orthosis is to support the gait by keeping the toe clearance. However, the conventional ankle orthosis with fixed joint restricts the motion of ankle because the ankle orthosis has no actuators. Therefore, the flexible and powered ankle orthosis is required to realize smooth walking. In this paper, a powered ankle orthosis with a progressive wave type ultrasonic motor (PUM) is proposed. To achieve smooth walking, a fuzzy reference generator and a fuzzy feedforward controller are introduced. The objective of the fuzzy reference generator is to estimate the appropriate ankle motion, which is obtained from the walking experiments for a person without handicap.The fuzzy feedforward controller is used to improve the tracking performance of the ankle positioning system. The effectiveness of the proposed ankle orthosis is demonstrated by experiments.
This study aims to investigate the intelligence which realizes emotional and physical communication between human and robots. This paper describes the autonomous robot named WAMOEBA 2R which can communicate with humans by both informational and physical way. WAMOEBA-2R has the two arms of which each joint has torque sensor controlled by distributed agent network system. The coefficients in the network architecture are autonomously acquired by using the feedback-error-learning algorithm. We surveyed 150 visitors at the '99 International Robot Exhibition held in Tokyo (Oct. 1999) and 74 visitors at the '99 Tottori Industrial Technology Fair held in Tottori (Nov. 1999) to evaluate their psychological impressions of WAMOEBA-2R. As a result, some factors of the human-robot emotional communication were discovered.
An inherently safe human-symbiotic robot is investigated in accordance with the procedure of International Standard of Organization (ISO) of machine safety. The term “Inherently safe design” was defined, but systematic realization of the term has not been given clearly. In this paper, two ways of realization of inherent safety of the robot are investigated as inching control with a brake and impact relaxation by using smart suspension of Magnet-Rheological Fluid (MRF). Both can secure safe contact between human and the robot based on human compliant structure and tolerance to applied force and impact force.
Pedaling is a typical example of the problem of man-machine interaction. The design of machines and bicycles that makes full use of human capabilities is an old but still challenging engineering problem. This paper describles the optimal design of a bicycle from several viewpoints such as kinematics, statics, dynamics, and physiology. The efficacy of a new mechanism called “magic crank” that realizes an unconventional non-circular pedaling trajectory is also discussed.