We have developed a DOA-based local area positioning system for position measurement of autonomous sweeping robot“SuiPPi”. This system can reduce the cost of the positioning system because it consists of a few components such as beacons, an array antenna and a signal processing unit. We have gotten the same accuracy as that of conventional TDOA system using wireless LAN. If beacons are placed at intervals of 20 [m], we can provide a positioning information of the robot in the accuracy of about 2 [m] .
In this paper, we propose a new approach for a humanoid balance control. In previous research, a balance control of a humanoid was regarded as a method which absorbs the difference of assumed environment model and real environment. In contrast, we focus on generating gird motions using prediction of time series of external force. We introduce a disturbance preview control method to generate gird behavior against external impact. In order to reduce ZMP error at the moment of external impact, we control desired COG trajectory by using a disturbance preview control that takes future information of an external force represented as velocity disturbance of COG. We show numerical simulation results and clash experiments using a small humanoid robot HOAP-2.
The long and thin snake-like robots have became popular for searching narrow spaces, such as debris of the collapsed buildings under the impact of large-scale disasters. Till now, most of the previous research efforts on snake-like robots have primarily focused on development of its mobility or its locomotion. In this research we present the development of a snake-like robot under remote control operation. The present paper gives a detailed description of the mechanism and the construction of the developed snake-like rescue robot KOHGA. This double headed snake-like rescue robot KOHGA can present an operator the image from the viewpoint of a robot's rear side by changing its form into scorpion shape mode. The usefulness of the scorpion mode is amply verified by performing several successful experiments.
A fast online legged motion planning method is proposed. It utilizes a general solution of the equation of motion of an approximate dynamical biped model whose mass is concentrated to the center of mass in the analytical form. Physically feasible referential trajectories are planned from only one step command of desired motion by relaxing boundary condition, namely, by admitting some error between the desired state and actually reached one. It potentially creates responsive motion which requires strong instantaneous acceleration by accepting discontinuity of ZMP. The validity of the proposed method is ensured through both simulations and experiments with a small anthropomorphic robot.
This study proposes a unique flexible robot with new hydrostatic skeleton driving mechanism. The main components of the robot are a hermetically-sealed outer cover with looped structure and flexible crawlers with hydrostatic skeleton named HS crawlers. This new robot provides remarkable advantages in narrow spaces as listed below: (i) the robot can change its shape adapting to terrain, (ii) all ground contact areas of the robot are driven toward the same direction. Performance of the first prototype robot is verified by experiments of wireless driving and passing narrow space. The prototype robot demonstrated a capability to pass through a space of 300 [mm] height, whereas the ordinary height of the robot is 420 [mm] .
This paper presents modeling and control of omnidirectional mobile robots propelled by active-casters (poweredcasters) . This type of mobile robot is redundantly actuated since it is controlled by more than four motors while its configuration is represented by three DOF on the ground. The modeling method is generalized down to n-wheeled mobile robots and a unified modeling procedure is presented for flexible designs with variety of wheel layout. The kinematic model derived by proposed method enables continuous linear full state feedback control with no consideration for singular configurations of robots. Performances of three- and fourwheeled robots with full state feedback controllers and proposed kinematic models are tested by computer simulations. Furthermore, a three-wheeled robot prototype is design, built and tested for the verification of the proposed modeling and control method for omnidirectional mobile robots in the real world.
A new design concept of space manipulator has been proposed, which is called Torque-unit Manipulator (TUM) . Each joint of TUM is free and a device which is called “torque unit” is equipped on each link. The “torque unit” can be made easily of a DC motor and a disc, for example. Position-controllability of the links of TUM has been shown with conventional control laws for manipulators, however some of state variables cannot be controlled when such control laws are used. When such control laws are used, positions of the links are controlled to desired positions but the angular velocities of the discs usually do not come to zero and result to be constant. The reason is that TUM is a kind of nonholonomic system and hence the angular velocity of each disc at each time depends on the trajectories of the links. In this paper, a progress is made in the study of trajectory planning for 2-dimensional N d.o.f. TUM to control the positions of the links and the angular velocities of the discs. A possibility is considered to control the position of each link to desired position and the angular velocity of each disc to desired constant value which is not zero.
When the end effecter of a serial robot passes through the vicinity of a singular point, some joint must move about 180 degrees in a short period, and, in many cases, a robot must be stopped by the limitation of the velocities of actuators. Though the velocities at a singular point cannot be determined by the Jacobian matrix, it is shown that they can be determined mathematically when the linearly independent joints span a Lie algebra. Thus the end effecter can path through a Lie algebraic singular point. The novel method for passing through a singular point is proposed for a serial robot by changing the orientation path at the vicinity of a singular point. This modification makes it possible for a robot to pass through the singular point located at the most vicinity of the original trajectory. Some numerical examples show that the robot can passes through the singular point in the permissive velocities.
In recent years, robotics research has been shifting from industrial to domestic application, and several domestic, human centered robots, aimed at communicating expressively with human, have been developed. In this research, a novel robot, Ifbot, which can communicate with human by joyful conversation and emotional facial expression has been developed by our industry-university joint research project. For robots to live with people, communication, even if it is between robots and human, should involve not only conveying messages or instructions but also psychological interaction, such as comprehending mutual sentiments, sympathizing with the other person, and enjoying conversation itself. To communicate this way, a robot requires several mechanisms that enable the robot to recognize human emotions, to have emotions, and to express emotions. This paper focuses into an emotion generation method so as robot to have emotion. We think it is necessary that robot has a likability to it's dialogist for having humanlike emotion. This paper proposes an emotion generation model based on the dialogist likability and implement the model on Ifbot. This paper also reports the experiments of emotional conversation with Ifbot. We have confirmed from the experimental results that a change in emotion during conversation is caused by the difference of the dialogist likability, and the change brings a dialogist a certain psychological effect.
Researchers in developmental psychology have reported various findings about animate-inanimate distinctions, especially the decision criteria of human infants categorizing animate existence, such as distinguishing animals and humans from the inanimate. The purpose of our research is to develop animate or “lifelike” behavior for communication robots based on such categorizing, which would be expected to potentially make human-robot interaction more natural. Thus we proposed a design guide of developing lifelike robots from the findings and implemented lifelike behavior into a humanoid robot based on our proposed guide. Our approach is also unique because we focus on the robot's mechanism and behavior design using environmental sensors. Consequently, we use a motion capturing system, which enables us to leapfrog technological developments for the robots' sensing abilities. Two experiments were conducted to verify its effects. The results of the first experiment verified the effectiveness of our proposed design guide. The second experiment demonstrated the effectiveness of the developed robot for investigating the effect of a robot's cognitive ability for human-robot interaction.