Range Image Sensor Research Articles

Development of Obstacle Recognition System of Humanoids Using Relative Disparity Maps from Small Range Image Sensors

We discuss the recognition of obstacles by detecting a plane using relative disparity maps obtained from a small range image sensor incorporated in a humanoid. Our proposal enables easy plane detection and obstacle recognition using relative disparity from a reference plane alone. We built an integrated controller that feeds back obstacle information to the humanoid. We confirmed through experiments that the humanoid recognized obstacles and autonomously stopped walking.

Vibration Estimation of Flexible Space Structures using Range Imaging Sensors

Future space applications will require robotic systems to assemble, inspect, and maintain large space structures in orbit. For effective planning and control, robots will need to know the deformation and vibration of the structures with which they interact. This paper presents a method for estimating the shape, motion, and dynamic model parameters of a vibrating space structure using range imaging sensors. The method assumes that the mode shapes are approximately known a priori. An unscented Kalman filter exploits a mechanics-based dynamic model to extract the modal frequencies and damping as well as the modal coefficients and their time rate of change. Both asynchronous-capture (raster-scanning) and synchronous-capture sensors are treated. Theoretical development and experimental results using emulated space hardware are presented.

17-5 背景光低減構造を持つQVGAサイズTOF距離画像センサ(第17部門 情報センシング2)

17-5 背景光低減構造を持つQVGAサイズTOF距離画像センサ(第17部門 情報センシング2)

1A1-D24 小型距離画像センサを用いたヒューマノイド歩行中における障害物認識

This paper deals with a target that a humanoid with a small range image sensor recognizes obstacles and avoid them autonomously while walking. Planar regions, on which the humanoid can walk, and obstacles are distinguished by using a relative disparity image obtained by a small range image sensor. In addition, an integrated system that can feed back obtained obstacle information to the humanoid is constructed. Experiments show that the humanoid can recognize obstacles and stop walking autonomously by the proposed system.

7-4 A Wide Dynamic Range Image Sensor Integrating Column Parallel A/D Converters with Column FPN Cancellation

7-4 A Wide Dynamic Range Image Sensor Integrating Column Parallel A/D Converters with Column FPN Cancellation

A new active pixel structure with a pinned photodiode for wide dynamic range image sensors

A wide dynamic range CMOS image sensor based on a new active pixel structure with a pinned photodiode is proposed and evaluated with device simulations. The proposed pixel device has a linear and a logarithmic characteristics in low and high illumination region, respectively. The technique of direct detection of photodiode potential leads to a wide logarithmic response compared with the conventional linear-log wide DR image sensor with pinned photo diode.

Input of Japanese Characters by Recognizing the Number of Fingers

Many recent studies centered on recognizing human gestures using images for man-machine interfaces do not deal with information on Japanese or other characters. We propose inputting Japanese characters by recognizing the number of fingers of one hand. Recognized numbers are converted to characters using the “pocket-bell” rule. The number is recognized by image processing. Range images are used as image information to implement the method. We also discuss how to control recognition timing and canceling input data. Experimental results using a range image sensor show the effectiveness of the proposed methods.

小型距離画像センサにより得られる相対視差画像を用いた平面領域検出 : 二足歩行ロボットへの応用(3次元計測/センサフュージョン)

小型距離画像センサにより得られる相対視差画像を用いた平面領域検出 : 二足歩行ロボットへの応用(3次元計測/センサフュージョン)

A study on a evaluation method for wide dynamic range image sensor

A study on a evaluation method for wide dynamic range image sensor

1P1-N5 マルチスポット光を用いた距離画像センサのキャリブレーション手法の提案(67. 3次元計測)

1P1-N5 マルチスポット光を用いた距離画像センサのキャリブレーション手法の提案(67. 3次元計測)

1P1-N4 小型距離画像センサを用いた移動ロボットの障害物回避手法の提案(67. 3次元計測)

1P1-N4 小型距離画像センサを用いた移動ロボットの障害物回避手法の提案(67. 3次元計測)

Real-time tracking of free object based on measurement and synthesis of range image sequence

Measurement and recognition of moving objects by a visual system is crucial to realization of robots that can handle a changing environment flexibly. In this article, we propose a system that tracks 6-DOF motion of a solid object of any shape in real time using a range image sequence. We compare range images measured by the Silicon Range Finder high-speed range image sensor with those synthesized from a computer model, and we assert that motion can be estimated independently of the form of objects. Furthermore, we propose a method to generate range images from a model very rapidly with CG rendering hardware. We also describe a process to model the shape of objects simultaneously with tracking, and a method to keep the object within the measurement region by rotating the measurement direction of the sensors. We performed experiments to verify the effectiveness of our method and found that all processes were performed at a speed of 7 frames per second and that the measurement errors were less than 1% of the scope of measurement. © 1999 Scripta Technica, Syst Comp Jpn, 30(5): 56–64, 1999

Three-dimensional vision system for mechanical assembly/disassembly

This paper proposes a three-dimensional (3D) vision system based on range image processing for mechanical assembly and disassembly. In the field of assembly and, moreover, because of the increasing importance of recycling of industrial products, in the field of disassembly, a more flexible vision system is required. Conventional intensity image processing is not sufficient and so a 3D vision system is required. A prototype of a vision system with a high-speed range image sensor is constructed, and its robustness for assembly and disassembly is verified by experiments to detect a target region (dial of an audio amplifier) with blemishes. Shape recognition algorithms which are applicable to sparse range images of the 3D vision system are introduced. They utilize primitive surface features such as planar or cylindrical surfaces as features for model matching. Fundamental experiments show the effectiveness of the general shape recognition algorithms.

A LED-array-based range-imaging sensor for fast three-dimensional shape measurements

Abstract An angular scan triangulation range sensor using an integrated array of light-emitting diodes (LEDs) and a lateral-effect position-sensing detector is described here. A range map is obtained by means of fast electronic scanning of the LEDs of the array. No moving parts are needed for the scanning. The sensor consists of a transmitter, a receiver and control electronics. The source used by the transmitter module is an array of 32 LED chips. Collimating optics are attached to the source. The receiver includes focusing optics and a one-dimensional position-sensing detector. The transmitter and receiver modules are connected to a computer, which controls the operation of the transmitter by supervising the sequential scanning of the sources in the array and determining the speed of scanning, and of the receiver by providing gain control, reading of the detector output signals and executing signal processing. The sensor output is a set of object surface coordinates or other parameters describing the shape, size and position of the object. In the tests the sensor has been used for profile measurements of cylindrical objects. For a wooden log surface placed at a distance of about 1200 mm, the diameter is estimated with an accuracy better than 2%. Based on the experimental tests of the scanner within the range 0.2–2 m, it is found that the performance of the sensor is sufficient for many applications in profile measurement and obstacle detection in robotics and machine automation.

Manhattan: A Fast (CEM) Reconstruction Method

Building a Cartesian Elevation Map (CEM) is the required step that allows a path planning subsystem to find a possible way for an autonomous vehicle to go. The (CEM) should provide a 3-D world model for the mobile robot and should be simple enough to permit a fast obstacle detection. The aim of this work is to present a fast CEM reconstruction algorithm that also recovers the position and the size of the obstacles for both indoor and outdoor scenes. Obstacles detection is directly performed on the range image (sensor map). The algorithm is able to classify each pixel in the CEM as unexplored, occluded (the algorithm gives the maximum possible elevation), traversable and obstacle. The method is tested on both an outdoor scene of rocks and an indoor scene of blocks and green plants.

Active, optical range imaging sensors

Active, optical range imaging sensors collect three-dimensional coordinate data from object surfaces and can be useful in a wide variety of automation applications, including shape acquisition, bin picking, assembly, inspection, gaging, robot navigation, medical diagnosis, and cartography. They are unique imaging devices in that the image data points explicitly represent scene surface geometry in a sampled form. At least six different optical principles have been used to actively obtain range images: (1) radar, (2) triangulation, (3) moire, (4) holographic interferometry, (5) focusing, and (6) diffraction. In this survey, the relative capabilities of different sensors and sensing methods are evaluated using a figure of merit based on range accuracy, depth of field, and image acquisition time.