Shinya Hirano

Development of a nursing-care assistant robot RIBA that can lift a human in its arms

In aging societies, there is a strong demand for robotics to tackle problems caused by the aging population. Patient transfer, such as lifting and moving a bedridden patient from a bed to a wheelchair and back, is one of the most physically challenging tasks in nursing care, the burden of which should be reduced by the introduction of robot technologies. We have developed a new prototype robot named RIBA with human-type arms that is designed to perform heavy physical tasks requiring human contact, and we succeeded in transferring a human from a bed to a wheelchair and back. To use RIBA in changeable and realistic environments, cooperation between the caregiver and the robot is required. The caregiver takes responsibility for monitoring the environment and determining suitable actions, while the robot undertakes hard physical tasks. The instructions can be intuitively given by the caregiver to RIBA through tactile sensors using a newly proposed method named tactile guidance. In the present paper, we describe RIBAs design concept, its basic specifications, and the tactile guidance method. Experiments including the transfer of humans are also reported.

Development of a Rajiform Swimming Robot using Ionic Polymer Artificial Muscles

Ionic polymer-metal composite (IPMC), which is one of the electro-active polymer actuators, is expected as artificial muscles for robots. An interesting property of IPMC is that it requires water to work, therefore it is suitable for underwater robots. In this paper, we developed an underwater robot which mimics rajiform swimming, that is the swimming form of a ray fish. Fins are designed using sixteen IPMCs. For autonomous operation, miniaturization of the electrical devices such as a micro controllers and small amplifiers are performed. A simple traveling wave control input is employed to generate moment on the fin. In the experiment, propulsion speed is measured under various control parameters. Furthermore, incremental wave of the fin is observed although the amplitude of the control input is spatially uniform. We also discuss this phenomenon from the point of view of interaction between elasticity of the actuator and fluid dynamics

Generation of Human Care Behaviors by Human-Interactive Robot RI-MAN

Recently, active researches have been performed to increase a robots intelligence so as to realize the dexterous tasks in complex environment such as in the street or homes. However, since the skillful human-like task ability is so difficult to be formulated for the robot, not only the analytical and theoretical control researches but also the direct human motion mimetic approach is necessary. In this paper, we propose that to realize the environmental interactive tasks, such as human care tasks, it is insufficient to replay the human motion along. We show a novel motion generation approach to integrate the cognitive information into the mimic of human motions so as to realize the final complex task by the robot.

Tactile-based motion adjustment for the nursing-care assistant robot RIBA

In aging societies, there is a strong demand for robotics to tackle problems resulting from the aging population. Patient transfer, such as lifting and moving a bedridden patient from a bed to a wheelchair and back, is one of the most physically challenging tasks in nursing care. We have developed a prototype nursing-care assistant robot, RIBA, that can conduct patient transfer using human-type arms. The basic robot motion trajectories are created by interpolating several postures designated in advance. To accomplish more flexible and suitable motion, adjustment using sensor information is necessary, because the patients posture and positions in contact with the robot may differ slightly in each trial. In this paper, we propose a motion adjustment method in patient lifting using tactile sensors mounted on the robot arms. The results of experiments using a lifesize dummy are also presented.

Whole-body contact manipulation using tactile information for the nursing-care assistant robot RIBA

In aging societies, there is a strong demand for robotics to tackle problems resulting from the aging population. We have developed a prototype nursing-care assistant robot, RIBA, which was designed to come in direct contact with patients and conduct physically challenging tasks. RIBA interacts with its object, typically a human, through multiple and distributed contact regions on its arms and body. To obtain information on such whole-body contact, RIBA has tactile sensors on a wide area of its arms. The regions where hard contact with the manipulated person may occur have almost flat surfaces, leading to surface contact involving a finite area, in order to reduce contact pressure and not to cause the persons pain. When controlling the position and orientation of the person, the relative positions and orientations of the distributed contacting surfaces should be preserved as far as possible to maintain stable contact and not to graze the persons skin. Preserving the force and the pressure pattern of each contact region using tactile feedback is also important to provide stable and comfortable human-robot physical interaction. In this paper, we propose a whole-body contact manipulation method using tactile information to meet these requirements.

Parametric excitation approaches to efficient dynamic bipedal walking

Traditionally, an inverted pendulum has been used as a reduced biped locomotion system, whereas this paper proposes a different approach. The essence of dynamic biped gait generation is mechanical energy restoration, and parametric excitation approach is a good idea for it. Our novel approach does not require any rotational actuation and thus enables to be free from the constraint of zero moment point (ZMP). This paper considers some basic methods of parametric excitation and shows that energy-efficient biped locomotion can achieved very easily without taking the ZMP condition into account. We then conduct parametric studies by adjusting the control and physical parameters, and determine how well the basic gait perform by introducing some performance indices.

Fast and Accurate Tactile Sensor System for a Human-Interactive Robot

With the advent of the aging society, the demand for nursing care for the elderly is becoming much larger. The application of robotics to helping on-site caregivers is consequently one of the most important new areas of robotics research. Such humaninteractive robots, which share humans’ environments and interact with them, should be covered with soft areal tactile sensors for safety, communication, and dextrous manipulation. Tactile sensors have interested many researchers and various types of tactile sensors have been proposed so far. Many tactile sensors have been developed on the basis of microelectro-mechanical system (MEMS) technology (for example, (Suzuki, 1993; Souza & Wise, 1997)). They have a high-density and narrow covering area realized by applying MEMS technology, and as a result, are not suitable for covering a large area of a robot’s surface. Some tactile sensors suitable for use on robot fingers or grippers have also been developed (Nakamura & Shinoda, 2001; Yamada et al., 2002; Shimojo et al., 2004). Many of them have the ability to detect tangential stress and can be used in grasping force control. Their main target is robot fingers, and consequently they were not designed to cover a large area. There are also commercially available tactile sensors such as those offered by Tekscan (Tekscan, 2008) based on pressure-sensitive ink or rubber, and KINOTEXTM tactile sensors (Reimer & Danisch, 1999) utilizing the change in the intensity of light scattered by the covering urethane foam when deformed. However, they are not sufficiently accurate because of strong hysteresis and creep characteristics. The idea of covering a large area of a robot’s surface with soft tactile skinlike sensors is attracting researchers (Lumelsky et al., 2001). Some human-interactive robots for which a large area of their surface is covered with soft tactile sensors have actually been developed (Inaba et al. 1996; Tajima et al. 2002; Kanda et al. 2002; Mitsunaga et al. 2006; Ohmura et al., 2006; Ohmura & Kuniyoshi, 2007). However, the tactile sensors are not suitable for humaninteractive robots, particularly when physical labor using tactile sensation is required. For example, one tactile sensor in (Tajima et al. 2002) has only 3 values as its output, and another tactile sensor in (Tajima et al. 2002) is gel-type and cannot be used over a long period because of the evaporation of the contained water. The tactile sensor in (Mitsunaga et al. 2006) has only 56 elements in total. Flexible fabric-based tactile sensors using an electrically conductive fabric have also been proposed for covering a robot (Inaba et al. 1996), but the O pe n A cc es s D at ab as e w w w .in te ch w eb .o rg

Landing Control of Acrobat Robot by RHC -Experimental Evaluation

In this paper, a nonlinear model predictive control (MPC) scheme for constrained mechanical systems with state discontinuity, or state jump, is considered, and a control method which extends a fast numerical algorithm based on continuation and GMRES methods, allowing online implementation for mechanical systems possible, is applied for. The validity of the strategy is demonstrated by a landing control for an acrobat robot based on a commercially available humanoid robot, KHR-1, where a general purpose compact computer system named C-CHIP developed at BMC is installed in the system

Adaptive user-centered design for safety and comfort of physical human nursing: care robot interaction

Nowadays serving robots are more and more popular in human society. However, most of them are designed for the special people or for the special scenario. There is little robot designed to apply appropriate interface for different people that can accommodate age-related and body-related in physical interaction. We propose that user-centered design should be used in physical Human-robot interaction. In this research, we take a nursing-care robot as an example. Based on the results of the experiment, we proved that the distance between two arms of nursing-care robot, which affected the comfort and safety of patient, should be applied by different patients with different body length. We try to build the adaptive human robot interface based on the physical properties of people, such as body length. This study is an attempt to explore the adaptive human robot interaction and contributes to giving insights and implications for the future design of general serving robot.

Falling-down avoidance control for acrobat robot by Q-Learning with Function Approximation

In this paper we consider a landing control of an acrobat robot by taking steps to avoid falling-down by applying Q-Learning with function approximation We use Q-leaning since it, is difficult to design controller systematically for an acrobat robot, a typical variable constraint and hybrid system. Since Q-learning requires large computation time on line, we use a function approximation to Q-table, and propose to update the Q-table and the approximate function alternatively. The validity of the proposed method will be demonstrated by numerical simulation and experiment.