Satoru Takahashi

Motion and shape identification with vision and range

In this paper, we consider the problem of motion and shape estimation using a camera and a laser range finder. The object considered is a plane which is undergoing a Riccati motion. The camera observes features on the moving plane perspectively. The range-finder camera is capable of obtaining the range of the plane along a given laser plane, which can either be kept fixed or can be altered in time. Finally, we assume that the identification is carried out as soon as the visual and range data is available, or after a suitable temporal integration. In each of these various cases, we derive to what extent the motion and shape parameters are identifiable and characterize the results as an orbit of a suitable group. The paper does not emphasize any specific choice of algorithm.

Motion and shape parameters identification with vision and range

In this paper, in order to get the better identification of motion and shape parameters of a plane dynamics, we apply the laser range finder data with vision using both a single laser range finder and a single CCD camera mounted on a mobile robot platform. The laser range finder makes a line on the moving plane along a horizontal laser plane. Namely, the laser range finder observes a cross section of the plane as a line. We use this time-varying line information for motion and shape parameter identification problems and show that when we use the laser range finder data with vision as the observation data the dimension of the parameter ambiguity in the only vision case can be reduced.

Optimal control theoretic splines and its application to mobile robot

Splines have been investigated as a basic tool of applied mathematics. First, the dynamics splines based on control theory were used in trajectory planning. Many researchers have studied some of the basic properties of splines from the viewpoint of optical control. We consider the method for generating smoothing splines using a control theoretic approach. Namely, we make generalized splines by solving an optimal control problem for linear systems. Then, we treat dependence on initial conditions. The important contribution in this paper is as follows: We introduce the new smoothing splines by optimizing not only over the control but also over the initial condition data.

Visual Feedback Tracking of Crane Hook

In this paper, we develop an observation device to measure a 3D position for a moving object by using a laser range finder and a CCD camera. Then, we propose new method for the object recognition and the tracking control, respectively. As for the recognition, we use a special mark which is called the cross mark. For the tracking control, we construct PID control with an extended Kalman filter to realize control system without delay. Through some experiments, we verify performance of observation device and show availability of our proposed method

Machining of Micro Dimples in Milling for Functional Surfaces

The paper presents a milling manner for machining of the micro dimples with an inclined ball end mill. When the inclined tool removes the material in a depth of cut of less than the tool radius, the non‐cutting time, during which all edges don’t remove the material, appears in a rotation of cutter. When the milling tool is fed so that the machining area does not overlap with the area removed by the previous edge during the non‐cutting time, the micro dimples are machined. The shapes and the alignment of the dimples are simulated for the cutting parameters in the mechanistic model. The cutting experiments were conducted to verify the micro dimple machining. Optical function on the surface is controlled by surface topography machined in the micro dimple machining.

Visual Feedback Control with Laser for the Position Detection of Crane Hook

In this paper, we introduce an development device which can measure the working radius of crane truck, automatically. This device is equipped with a laser range finder, a CCD camera and two AC servo motors. Each motor has an encoder. First, we propose the method of object recognition to measure the position of mark set of measurement object, and secondly construct the tracking control system to the development device. Then, it has PI control system with an extended Kalman filter. Through experiments, we show the effectiveness of our proposed method

Obstacle Avoidance Control for Mobile Robots based on Vision

This paper treats the navigation problem of mobile robots to avoid obstacles according to vision information. In our method, first we detect obstacles which exist in front of a mobile robot by calculating the optical flow. Then, based on the area of detection we decide the optimal trajectory for a robot. Here, we may use the sensor data for supporting a vision system. In order to find the optimal trajectory, we compute the distance between a mobile robot and obstacle evaluating a function. Through experiments, we show how our proposed method can avoid obstacles.

Clone Nursery Plant Trans-planting Robot System With 3-D Vision System

Today, vision systems for robots had been widely applied at many important applications. But 3-D vision systems for industrial uses should face to many practical problems. Here, a vision system for bio-production has been introduced. Clone nursery plants are one of the important applications of bio-technology. Most of the production processes of clone nursery plants are highly automated, but the transplanting process of the small nursery plants cannot be automated because the figures of small nursery plants are not stable and to handle the nursery plants it is required to observe the shapes of the small nursery plants. In this research, a vision system for robot to be used for the transplanting process in a plant factory has been introduced

Position Measurement of Crane Hook by Vision and Laser

In this paper, we develop the observation device which measures the working radius of a crane. To realize the measurement, the observation device has the CCD camera and the laser range finder, and the specific mark is attached to a crane. Then, we propose methods for the object recognition and the tracking control. As for the tracking control, to realize the control system without time delay, we construct PI control with an extended Kalman filter. It follows from some experiments that the observation device which we developed enables high accuracy measurement of the working radius of a crane

Modeling techniques of wooden buildings for cyberscapes of "Edo"

We have been restoring city landscape of Edo in the Edo era, based on archaeological documents, with 3DCG. Edo is old name of Tokyo. We call the city landscape restored with 3DCG as cyberspace hereafter. As restoration methods of cyberscapes, several procedural models[1][2] have been proposed, by which buildings with stones and bricks were generated. However, it is difficult to apply them to generate wooden buildings without complete drawings and vulnerable to weathering.