WR-X is an integrated platform for use in high-performance robots, making it possible to build simple, low-cost ultra-high-performance robots that can withstand the rigors of full-scale research use. Using WR-X makes it easy for anybody to build a wide variety of robots simply by combining modules as with a Lego construction set. To keep costs low and realize suitability to a wide range of uses, WR-X's actuator employs a standard over-the-counter RC servo used in radio-controlled models. Using an RC servo for a robot's actuator presents a wide range of difficulties. To overcome these, we developed specialized servo-control hardware to control the RC servo motor directly at a high level. This has made it possible to achieve an actuator with linear torque properties for use in ultra-high-performance robots, using a low-cost RC servo. Furthermore, we also developed an accelerator for conducting hardware-based image-analysis computation, in order to achieve real-time image analysis, which had been difficult with traditional small robots. This system has successfully computed the positions of eight physical objects on a screen in a mere 15.7[μs], achieving a speed increase to approximately 60,000 times the speed of software-based computation.
This paper proposes a visual servo control algorithm with occlusion handling. The proposed control algorithm selects a set of correctly extracted image features, and it estimates all image features from the correctly extracted image features. The estimation procedure enables us to track image features even when occlusion occurs. In addition, even when the algorithm fails to track a moving image feature, it does not need any global search over the entire image plane to find the failed image feature. The image feature selection and estimation are combined with visual servo control in the proposed algorithm. The control algorithm has low computational complexity, since image Jacobian is used for image feature selection and estimation. An experimental result shows the validity of the proposed visual servo control law.
This paper proposes a local method to avoid collisions with continuous velocities. The main contribution of the method is that non-strictly convex polyhedra can be used as geometric models of the robot and the environment without any approximation. The problem of the continuous interaction generation between polyhedra is reduced to the continuous constraints generation between polygonal faces and the continuity of those constraints are managed by the combinatorics based on Voronoi regions of a face. A collision-free motion is obtained by solving an optimization problem defined by an objective function which describes a task and linear inequality constraints which do geometrical constraints to avoid collisions. The proposed method is examined using example cases of simple objects and also applied to a humanoid robot HRP-2.
The sampling real-time Q-MDP value method, which is a novel real-time decision making method under uncertain information, is proposed in this paper. The proposed method is implemented and evaluated on an autonomous goalkeeper robot for RoboCup four legged robot league. In the original Q-MDP value method, a proper action is chosen by calculations of expected values with the following data: 1) a planning result that is obtained with an assumption that information is perfectly known, and 2) a probability distribution that represents uncertainty of information in the planning space. The real-time Q-MDP method has utilized particle filters for real-time calculation of the values. The proposed method is an improved method of the real-time Q-MDP method. An proper action is chosen only a part of the particles in the proposed method. Faster or more proper decision making can be possible by sophisticated omission of calculations.
Rehabilitation treatments are important not only for persons who have something wrong in their upper limb function because of disease or disorder. Also they have benefits for the aged to exercise to keep their upper limb function. Since movements of the upper limbs are complicated, various and indispensable for daily activities. Application of robotics and virtual reality technology makes possible for new training methods and exercises on upper limb rehabilitation and for quantitative evaluations to enhance the qualitative effect of training. The authors have involved in a project managed by NEDO (New Energy and Industrial Technology Development Organization as a semi-governmental organization under the Ministry of Economy, Trade and Industry, Japan), “Rehabilitation System for the Upper Limbs and Lower Limbs,” and developed a 3-D and 3-DOF exercise machine for upper limb (EMUL) in which safety kept by actuators using ER fluid. In this paper, the authors focus on an aspect of EMUL; it is a force display device. The authors report virtual reality software of EMUL for rehabilitation training. They also describe some pretest using those software performed by able bodied persons, for clinical treatments in future work.
This paper reports a study about system response time (SRT) in communication robots that utilize human-like social features, such as anthropomorphic appearance and conversation in natural language. Our research purpose established a design guideline for SRT in communication robots. The first experiment observed user preferences toward different SRTs in interaction with a robot. In other existing user interfaces, faster response is usually preferred. In contrast, our experimental result indicated that user preference for SRT in a communication robot is highest at one second, and user preference ratings level off at two seconds. However, a robot cannot always respond in such a short time as one or two seconds. Thus, the important question is “What should a robot do if it cannot respond quickly enough?” The second experiment tested the effectiveness of a conversational filler: behavior to notify listeners that the robot is going to respond. We used the same strategy in a communication robot to shadow system response time. Our results indicated that using a conversational filler by the robot moderated the user's impression toward a long SRT. Put it all together, we obtained a) users'; impressions toward the robot are unchanged until one second SRT, b) the robot should react within two seconds SRT, and c) use of conversational fillers are effective to let the users to wait from these two experiments.
Low energy biped walking style is proposed, where self synchronized mechanical motion is continuously stabilized by some actuations triggered by sensing signal. Self synchronizing sideways motion is based on a two point support inverse pendulum, where stepping cycle time is controlled by a small variation of actuation. Contrarily, self synchronizing forward leg swing is based on a pendulum, where maximum forward angle is produced in a half cycle time of natural swing frequency. Two experimental robots of air-cylinder plus DD motor model and 7-servo motor model are developed. The former one makes kicking motion to make a sideways undulation triggered by a signal of gyroscope, and makes leg swing actuated by a direct-drive motor on a center of hip joint. The latter makes posture change triggered by gyroscope to get gravity energy to keep sideways undulation, and simultaneously, makes leg swing actuated by low gain position control of hip joints. The performance of these robots are demonstrated by experiments.
In the past decade, search type rescue robots have been focused on. Most robots took “linked mobile track” type such as snakes, so as to obtain high quality against unknown irregular surfaces. However the linked mobile track has some joints and sometimes they shut in some debris and stuck on it. In addition, many links increase total weight of robots and control complexity. In the paper, we propose a new type mobile mechanism, Flexible Mono-Tread Mobile Track (FMT) and develop a prototype called “Rescue mobile Track No.2 (RT02) WORMY”. The prototype consists of a flexible chain and a vertebrae like structure. Moreover, we investigate its performance against the irregular surfaces.
The community test of developed On-demand Bus system, which users can assign time freely in reservation, was held in Unzen city, Nagasaki prefecture. According to the test, it was shown that the convenience of users could be increased by the unique function of developed On-demand Bus that users could assign time and system estimated accurate arrival time. As a result, 72.6% of passengers agree to pay higher fare than the existing route bus for moving by developed On-demand Bus.