We have been researching and developing a Home Healthcare System using communication robot technologies (Communication RT) that supports a worry-free home life for older persons. Through a communication robot system with voice interaction, a graphical user interface and a chair with built-in health data sensing devices, the system determines the user's state of health from the results of blood-pressure, body temperature, weight and information obtained by a medical interview. One of the serious problem is that users cannot continue daily measurement, so we target a Home Healthcare System that motivates and supports older users to maintain their daily routines through communication robot technologies. The experimental prototype and long term in-home experiments are described here.
This paper describes a novel approach to linguistic mutual inference, which enables robots not only to linguistically interpret the motion patterns as sentences but also to recall the motions from the sentences. The inference can be established based on the motion language model and the natural language model. The motion language model stochastically connects the symbols of motion patterns to the words through the latent states which represent the underlying linguistic structure. The natural language model represents sequences of words. The motion language model and the natural language model correspond to semantics and syntax respectively. The integration of the motion language model and the natural language model allows the linguistic mutual inference for the robots . The two kinds of inference can be made by solving search problems: search for a sequence of words and a symbol of motion pattern. The proposed approach to interpretation of motion patterns as sentences and recall of motion patterns from the sentences through integration of the motion language model and the natural language model is validated by the experiment on the human behavioral data.
We propose a path planning method for mobile robots to avoid a person dynamically using movement prediction model from massive captured people trajectories. The captured trajectories are represented as a sequence of grid cells. The method learns these sequences using Variable Length Markov Model (VLMM), which predicts human location from the last human path. Based on the learnt model, the method plans mobile robot path on the XYT configuration space that includes predicted human position. In the experiment, we collected the trajectory data in the corridor space for over a month and simulated our planning method. The result showed that human trajectory model is more suitable than linear motion model for the safety robot navigation and the longer observation of trajectories improved the safety at mobile robot navigation.
This study deals with the avoidance/mitigation possibility in severity estimation of harm from a mechanical hazard when a sharp-edged object approaches to a human eye part. We assume that a sharp end effector of a robot approaches the eye of a human in a human-robot coexistence system. We conduct a static eye part collision experiment and dynamic eye part collision experiment taking human avoidance/mitigation actions into consideration. Three conditions, open/close eyelid, collision positions, and collision angles, are changed in the static collision experiment. Consequently, it is confirmed that differences in severity come out from the changes in the experimental conditions. In the dynamic collision experiment, Bell's phenomenon, which is an upward rotation of the eyeball at the time of closing the eyelid, is taken into consideration and two conditions, collision positions and angles, are changed. Through the experiments, we find that Bell's phenomenon plays an important role for risk estimation. Although the avoidance/mitigation possibility has not been taken into consideration in eye part collision experiments, we consider that it is indispensable to risk estimation.
The present paper describes a newly proposed method of planning the CoM trajectory that realizes the desired ZMP. We introduce the permissible ZMP region as well as the desired ZMP trajectory. When the robot suffers from disturbances, the ZMP trajectory desired in the future is adjusted and the future permissible region is used evenly in order to suppress the change of the ZMP at the moment of disturbance. The proposed method is based on the CoM trajectory generation method that uses preview control theory. Simulation results reveal the feasibility of the proposed method. The proposed method is then implemented as a part of walking control system of HRP-2, which generates a walking pattern that starts from the estimated actual robot motion at 40 [Hz]. Walking experiments on unknown terrain are conducted in order to demonstrate the performance of the proposed method.
To understand the principles of human hand dexterity, investigation of dynamic contact control by the hand is essential. This paper proposes a novel high-density tactile sensing glove lined with sensor sheets, which were flexible printed circuit boards embedded with 1-[mm]-sized pressure sensitive elements at 1,052 points per hand. The sensor sheets were tree-shaped, especially designed to accommodate deformations of the skin in order to minimize interference of the wearer's natural finger movements. The design also permitted seamless coverage and allowed the tactile sensor elements to be distributed at a high density over the entire inner surface of the hand. In our experiment, we found that our tactile sensor sheets reduced interference of joint movements by one-third compared to existing tactile sensors. Moreover, we verified that our glove makes qualitatively consistent measurements of pressure distributions over the surface of hand for each of everyday objects handled by the wearer despite large deformations in the skin.
In this research, we propose a producing method of softness sensation using a pinching type tactile device. The producing method of softness sensation which is significant information during the pinching motion by a human is proposed. The basically idea is apply a vibration to fingertip by the pinching type tactile device to increase receptor activity. A white noise and database which is made from experimental result in this paper, are used to generate the vibration. First, we conduct a basic experiment to decide the appropriate waveform of vibration. Finally, we conduct the evaluation experiment of softness perception. The subjective experimental result indicates that the proposed method can be used to produce softness sensation.
This paper presents the high-speed microrobot driven by permanent magnet in a microfluidic chip. The comprehensive analysis of fluid force, the optimum design and its fabrication was conducted to reduce the fluid force on the magnetically driven microrobot by developing fine V groove pattern on the microrobot. Riblet surface, which is regularly arrayed V grooves, were employed to reduce fluid friction on the microrobot. The upward force is generated by the wedge effect and it generates lubricant film thickness between the microrobot and the glass substrates. Optimization process was conducted to design riblet surface on the microrobot in order to maximize lubricant film thickness. The Ni and Si composite fabrication was employed to form the optimum riblet shape by anisotropic Silicon (Si) wet etching and deep reactive ion etching. The evaluation experiments show the microrobot can be actuated up to 90 Hz, which is about 10 times higher than the original microrobot.
In this paper, we propose a compliant—parallel mechanism that enables a wide working area and a high accuracy. The compliant—parallel mechanism is a parallel mechanism that all joints are composed by largely deformable springs. Designing the compliant joints for the mechanism let us explore new challenges: The joints should be elastic for the desired direction, but also rigid for non-desired direction to be deformed. The stress applied during the deformation must not exceed the yield stress to prevent the fatigue failure. The processing method should be carefully considered to minimize the individual variability of spring characteristics. The energetic efficiency also must be taken into account for designing the mechanism. Considering these issues, we developed a new compliant joint structure - alternate side slits structure to be applied to the mechanism. We conducted FEM analysis to clarify the effectiveness of the proposed spring, and the spring was implemented to a prototype, that was designed based on a well known parallel mechanism, DELTA within 50×50×5[mm] of working area. The evaluation tests conducted on the prototype showed 0.46[μm] of repeatability in average and 94.3[N/mm] of rigidity in Z axis, that are promising to be applied for an optical parts assembly system.