Eye Movement Tracking Type Image Display System can display wide view angle image with high resolution using human eye characteristics although conventional displays are used. The principle is that a small high-resolution image is presented at the viewpoint and a wide view angle image of low resolution is presented in the peripheral area by using two displays. Human can see an object as a high-resolution image only near the viewpoint. Therefore, the operator can feel that the displayed image has wide view angle and high resolution. In this paper, the structure of the image capturing and the displaying system are examined. The displaying condition of the high-resolution image is discussed. An evaluation of the high-resolution image displaying, which is followed by eye movement, is introduced using the proto-type system.
A mobile robot can use the walls or the pillars to localize itself when it navigates in indoor environment. However, in open space or outdoor environment there are few easy detectable and stable objects that the robot can use. In this paper, we propose a method for the detection of braille blocks, which are originally used for visually handicapped people, for autonomous mobile robot navigation. To recognize the Braille block, a CCD camera and a laser fan beam projector are used as sensor to detect uneven surface of the blocks. This paper also present the experimental results of simple navigation using the sensor system.
In order to create agile locomotion for legged robots, so far various methods have been proposed with the concept of neural circuits, or so-called Central Pattern Generator (CPG) . In contrast to these approaches in which monolithic CPG neural circuits are employed to control locomotion, this paper focus on a polymorphic CPG neural circuit. This allows us to dynamically change the properties of CPG circuit according to the current situation in real-time. To this aim, the concept of neuromodulation mechanism is introduced to modulate a CPG circuit. To verify the feasibility of this approach, this concept is applied to the control of a 3-D biped robot which is intrinsically unstable. In order to explore the parameters of the CPG circuit with a neuromodulation mechanism, an evolutionary algorithm is employed in this study. Simulation results show that the neuromodulation mechanism dynamically changes synaptic weights of the CPG circuit. This synaptic change leads to creating different behaviors, such as walking behavior and stepping behavior, from the same circuit.
In this paper, we propose a mechanical impedance control for the whole arm of a serial-chain manipulator. The proposed whole-arm impedance has a geometrically natural property called spatial affinity owing to use of a spatial curve which describes a virtual reference of the impedance. Simulation results clearly show the natural enveloping property of the proposed control.
This paper describes a gait generating network for a hexapod robot under various curvature turnings. Formica japonica Motschulsky, that is one of major ant with about 6 [mm] body length in Japan, was used for a gait analysis. Movements of the leg joints during free walking was recoded at 60 to 250 [frame/s] by a high-speed video camera. From the data, we found that the turning gaits were classified into two distinct patterns: a sharp turning gait in which case the radius of curvature is under 5 [mm], a gradual turning gait in which case that is 5 to 40 [mm] . A turning gait generating network, which was possible to generate each gait and to vary a radius of curvature, was devised. That is a neural network which is described by neurons and connections between them using excitation and inhibition. We made a hexapod robot with 3 DOF each leg and verified the accountability of the gait generating network using the robot. As a result, smooth and stable turning in different curvatures was achieved.
We propose a novel complementarity model for a general three-dimensional manipulation system with the transitions of contact modes (rolling, sliding and breaking contact points) to solve the forward dynamics problem. The key idea is to construct a dynamic model with contact dynamics and to derive complementary constraints for a rolling contact by decomposing the tangential properties. We also present the Existence and uniqueness of a solution to the model, and propose algorithms for solving the problem. We show examples of computer simulation for dynamics of multi-fingered hand manipulation and discuss how the transition of contact modes varies according to the magnitudes of the friction coefficient and the applied joint driving torques.
Modular component assembly has become a dominant trend in the final assembly process at automobile manufacturers. The modular component assembly system poses a problem of installation difficulty, since modular components are heavier and larger than individual parts. To solve this problem, a new type of assist device has been proposed, which reduces the operating force required by workers to install a large modular component on a vehicle body. This new device was named “Skill-Assist” . Skill-Assist contains two electric actuators to meet horizontal operating force requirements. Actuator control emphasizes improved subjective operational feel, so that operators can manipulate Skill-Assist intuitively, making optimal use of the skills they have acquired through their work experience. Before Skill-Assist was actually applied to a cockpit module installation process, the risk-assessment protocol established in Europe was adopted to ensure the operator's safety which is essential for an assist device to work interactively with human operators in a shared workspace. Actual application has confirmed that Skill-Assist is effective not only in reducing the physical workload on human workers and installation work time requirements, but also in improving the subjective operational feel and utilizing workers' acquired skills. Further, Skill-Assists have not brought any hazardous situation due to the safety measures taken.
A new approach to collision-free path planning for a telerobotic manipulator is proposed. Using swept volume of a slave manipulator tele-operated by a human operator, on-line transition to autonomous tele-operation from master-slave manipulation is achieved without any geometric model of an environment. This feature enables wider application to unstructured environment.
This paper presents a novel method for the whole body teleoperation of a humanoid robot using simple input device. A typical humanoid robot would have more than 20 DOF. Due to the complexity, it requires an effective way for whole body teleoperation. Getting hints from the shifting of locus of attention for body motions between the joints of human body during task executions, this paper proposes a switching command based whole body teleoperation method. Instead of giving command to all joints all the time, the operator selects only the necessary point of the humanoid robot for teleoperation. This switching teleoperation method enables flexible teleoperation of humanoid robots using only simple input devices. The proposed method is implemented as a teleoperation system using two 3 DOF joysticks to operate a real 30 DOF humanoid robot, HRP-1S, which is developed in the Humanoid Robotics Project of the Ministry of Economy, Trade and Industry of Japan. The effectiveness of the proposed method is confirmed with experiments teleoperating HRP-1S.
Legged locomotion has attracted many researchers' attention because it is very challenging to realize artificial systems which can generate the motion of legged animals with many degrees of freedom. Animals show marvellous autonomous adaptation abilities. It is well known that the motions of animals are controlled by internal nervous systems. In this paper, we propose a method to generate a three-dimensional locomotion based on structuring a simple model with neural oscillators, which generates locomotive patterns and sideways sway motion. The validity of the proposed method is verified using an autonomous quadruped robot.
In this paper, we consider the weight shift in biped double support phase under variable environment. In conven-tional method, motion pattern of body parts that leads the center of mass or center of pressure of ground reaction forces to the desired position is planned first, and then execute position al feedback against it. This indirect method causes problems such that the planned motion pattern is not suitable, or how this pattern should be modified, for the varied environment. Here, we show that, by selecting the center of pressure as the controlled variable, not only the motion planning of body part becomes unnecessary, but also the motion pattern automatically changes with the environmental conditions. The stability of the control method is discussed and its validness is examined by simulations and robot experiments.