Teaching a sensor enhanced robot under many task constraints is very difficult even for skilled operators, let alone novice operators. The problem is that the indexes for performing a robotic task, which the operators should simultaneously pay attention to, are not clear. To overcome this problem, we classify the task constraints into three indexes: for manipulator, tool and sensor. We substitute the weighted indexes into the null-space method and generate robot motion for performing a task. We use this method in a tool-manipulation task such as welding and experimentally confirm the usefulness for reflecting the operator's teaching skill on the end effector position and orientation using weights of indexes. Moreover we discuss the extraction of the operator's skills from teaching data as weights of these indexes.
Detecting the road region in an observed image is an important technique for visual navigation of an autonomous vehicle. In this paper, we propose a road detection method using stereo images. The method does not rely on the existence of any specific road painting or texture. Instead, it supposes that a road (or a passable part) can be approximated by a plane. Then, a homography matrix which represents a geometric relation between the road plane and the stereo images can be computed from the stereo images. And the road region can be detected in the observed image by transforming one image by the homography matrix and simple matching. In this method, neither a predetermined geometric relation between the cameras and the road nor a strong camera calibration are necessary. Experimental results with real scenes have shown the effectiveness of the proposed method.
The articulated body mobile robot KORYU possess a long snake like body configuration, and as like snakes, it has an intrinsic capability to perform manipulation adding degrees of freedom from its articulated body, and also using the body's locomotion freedom. In this paper, we explore these advantages to configure an augmented manipulator with effective integration of manipulation and steering control for the real mechanical model KR-II. This robot is equipped with a single link manipulator arm on its foremost segment, and thus the range of tasks for the original configuration is extremely limited. Computer simulation and experimental results are shown to demonstrate the validity of the manipulation configurations and the versatility of the proposed system.
In general, when the robot is made to walk, it is necessary to make the walking pattern which is called gait. In making this walking pattern, a known walking surface is assumed. And, the walking pattern is made by using the inverted pendulum model or the ZMP (Zero moment Point) criterion, etc. to walk on the surface. However, because unknown disturbance like unevenness etc. of surface exists actually even if the joint of robot is controlled to track to the walking pattern precisely, walking becomes unstable. It is described to be able to achieve a steady walking by adding the controller which regulates the walking pattern disturbed by an unknown uneven surface etc. to the joint servo system which tracks to the walking pattern in this paper. Moreover, it is shown to be able to derive the controller by the optimal regulator theory. Finally, this stabilizing control was installed in the biped walking robot and the result of the walking experiment of 3 kilometers an hour is described.
In this paper, we discuss an autonomous locomotion control of a snake-like robot which is modeled by some links with passive wheels. When the robot locomotes windingly, it should always keep the high locomotable shape, because its locomotability depends on its own shape. Then, we utilized a notion of manipulability to evaluate the locomotability, and proposed a controller to make it autonomously locomote in a desired direction without decreasing the manipulability. In this method, the robot spontaneously generates its gait, so we don't need to design any gaits. Moreover, by some simulations, it was proved that the method realizes the autonomous locomotion without taking singular postures.
A new approach to the deformation modeling of rheological objects for their shape control is presented. Manipulative operations of rheological objects can be found in many industrial fields such as food industry and medical product industry. Automatic operations of rheological objects are eagerly required in these fields. Since rheological objects deform during operation processes, it is necessary to simulate the behavior of the objects and to estimate their deformation for the automatic operations. Consequently, a model of a rheological object is needed for the simulation and the estimation of its deformation. We will propose a lattice structure based modeling method for rheological object deformation. First, behavior of viscoelastic models is briefly explained. Second, we will introduce a nonlinear damper (NLD) into a viscoelastic model in order to describe the deformation of rheological objects. Next, a rheological object is modeled as a lattice structure, where mass points are connected through viscoelastic models using an NLD. Model parameters of a rheological object are then estimated through a creep experiment. Finally, comparison between the behavior of an actual rheological object and that of an identified model will demonstrate the validity of the proposed model.
This paper proposes a robot which understands human satisfaction and takes adaptive behavior. The proposed robot has a theory of mind that estimates human mental state on satisfaction which is evaluated by the satisfaction measurement system based on electroencephalogram measurement. A physical robot named “adaptive behavioral companion robot with a theory of mind based on human satisfaction (ACM) ” is developed with emphasis on psychological interaction between autonomous robots and humans. ACOM has such unique functions as determining adaptive behavior to human based on learning which uses increase rate of satisfaction as the reward, and expressing emotions based on the reward which is given by how much human is satisfied by the adaptive behavior. Psychological impression of ACOM toward the human is examined through the interactive experiment between ACOM and human, showing the possibility of a robot with a mind from both subjective and objective evaluations.
We have proposed a new leg-wheel hybrid mobile robot named“Roller-Walker”. Roller-Walker is a vehicle with a special foot mechanism, which changes to a sole in walking mode and a passive wheel in skating mode. On rugged terrain the vehicle walks in leg mode, and on level or comparatively smooth terrain the vehicle makes wheeled locomotion by roller-skating using the passive wheels. The characteristics of Roller-Walker are: 1) it has a hybrid function but is light-weight, 2) it has the potential capability to exhibit high terrain adaptability in skating mode if the control method for roller-walking is fully investigated in the future. In this paper, the 4leg trajectory of straight roller-walk is optimized in order to achieve maximum constant velocity. Also steering roller-walk control method is proposed. It is obtained by the expansion of the straight roller-walk trajectory theory adding an offset to the swinging motion. This steering method resembles that of a car. The control system was modified into an untethered system, and control experiments were performed. The realization of the steering motion was verified by them.
In this paper, a new wheel mechanism for holonomic and omnidirectional mobile robots is presented. The caster drive technique is one of the feasible solutions to allow a vehicle to have holonomic and omnidirectional mobile capability with standard wheels. The caster drive is applied to a differential drive mechanism. A drive unit equips with two drive wheels driven by individual motors. The rotational stage, driven by the third motor, is mounted on the drive unit with its rotational center locating at the off centered position from the mid point of the two driving wheels. The translational position and velocity of a mobile base are controlled by the differential-drive mechanism executing a caster like behavior. The orientation of the mobile base is controlled by the rotational stage decoupled with the translational motion of the drive unit. The vehicle 3DOF are controlled by the three motors, hence the system includes no over constraint problem. In addition, the drive mechanism is very simple and could be implemented by using a traditional differential-drive mechanism.
This paper discusses a new sensing system termed as Tracing Type Artificial Active Antenna composed of a flexible beam anchored at the base with moment sensor, and an actuator for moving it. We consider a sufficient condition for detecting the surface shape by using the sensing system. We show that a straight-lined beam with one-axis moment sensor can achieve the requirement irrespective of contact friction, while a curved beam can not do it. We experimentally show that a straight-lined beam can detect the surface irregularity with pretty high sensitivity (≤5 [μm] ), even under different contact frictions. Knowing of such excellent sensitivity of the sensing system, we apply it for detecting the effective length of threads of mechanical parts after tapping.
A new method for calculating widths of regions in a segmented image is proposed. Width is one of invariant features of a region, and can be calculated using the boundary length and the area. However, the value may be affected by the shape of the region. We introduce a function to correct the error according to the shape using compactness, which is a feature showing the shape of the region. We made models for region shapes with a rectangle and a capsule-shape, and evaluated the error to be cancelled. Results for actual data are shown.
This paper presents the concept of sensor-fused telerobotics and its application to the space test of the Advanced Robotic Hand System, which is the world's first precise extravehicular robot aboard the satellite “Hikoboshi”. The telerobotic system has features of dexterity, autonomy and flexible operability, using a three-finger multisensory hand at a work site in space and a computer graphics-based desktop interface at an operation site on the ground. The system was launched, and its capability was successfully demonstrated in space. Integrated utilization of the five kinds of sensors and three-fingers are effective to perform precise tasks under the barrier of inter-satellite communication. Telesensing that acquires the work database interactively using the multisensory hand was introduced to overcome uncertainties in space tasks.