National Chung Shan Institute of Science and Technology

Chung-Shan Institute of Science and Technology, Armaments Bureau, M.n.d

Chung Shan Institute of Science and Technology

Chung-Shan Institute of Science and Technology, Armaments, Bureau, Ministry of National Defense

Yi-Yuh Hwang

Chin-Der Hwang

Li-Chung Liu

Wei-Guo Chang

Chih-Ming Liao

Shin-I Ma

Mau-Ran Wang

Ting-Wei Chiang

Wen-Cheng Huang

Guang-Sheen Liu

Wen-Chen Huang

Chun-Hao Chen

Wei-Kuo Chang

Ming Chen

Wen-Jen Lin

Ping-Ya Ko

Chih-ming Liao

A device for measuring repeated positioning precision of a robotic arm is introduced. Using an optical speckle three-dimensional displacement sensor developed by the inventor, and with collaboration of an optical speckle image three-dimensional positioning base built with an optical speckle coordinate database and having low thermal expansion, an optical speckle three-dimensional absolute positioning space is established. The optical speckle three-dimensional displacement sensor is installed on an end effector of a robotic arm, the robotic arm is moved to have the optical speckle three-dimensional displacement sensor enter an optical speckle three-dimensional absolute positioning space, an optical speckle image of a positioning point is captured and compared with a coordinate optical speckle image in the optical speckle coordinate database, and current three-dimensional absolute positioning coordinates of the end effector of the robotic arm can be obtained.

Device and method for measuring repeated positioning precision of robotic arm

The present invention provides a planar three-dimensional displacement sensor for a multiaxis machining device. With the measurement of the (planar) three-dimensional displacement sensor in the multiaxis machining device, the multiaxis machining device and a multiaxis machining compensation method are able to eliminate various deformation effects effectively.

Multiaxis machining device and compensation method thereof

The present invention is to provide a method of precisely comparing and positioning speckle patterns, which calculates light intensities of the speckle patterns, is capable of enhancing positioning accuracy of the speckle patterns, and is applicable to various navigation input devices for various types of notebook computers, multi-function keyboard and TV remote control.

Method of precisely comparing and positioning speckle patterns

An error compensation device includes at least one photographing module, a comparison module and a compensation module compensation module. The photographing module establish a space coordinate system relative to the object and comprises a first photographer and a second photographer which respectively photograph a first non-deformed laser speckle image on a first surface and a second non-deformed laser speckle image on a second surface, the first surface differs from the second surface by an azimuth. The comparison module respectively compares the first non-deformed laser speckle image before and after the displacement with the second non-deformed laser speckle image to calculate a displacement value between the two surfaces. The compensation module controls the movement of the object according to the displacement value. The error compensation utilizes the displacement of the non-deformed laser speckle image to obtain the absolute error of the object and compensate the error.

Error compensation device and error compensation method

A measurement, calibration and compensation system for machine tool includes a first positioning base; two first speckle image sensors for sensing speckle positions of an object holding unit at a first XY plane and a first XZ plane of the first positioning base before and after the machine tool is started for machining; a second positioning base; two second speckle image sensors for sensing speckle positions of a cutter holding unit at a second XY plane and a second YZ plane of the second positioning base before and after the machine tool is started for machining. Thus, the thermal expansion at all axes of the machine tool can be measured in a simplified and low-cost way, and the absolute positioning coordinates of all axes of the machine tool can be calibrated in real time to avoid reduced positioning accuracy due to the thermal expansion of the multi-axis machine tool.

Measurement, calibration and compensation system and method for machine tool

The present invention mainly provides a precision calibration method for being applied in a high-precise rotary encoder system, wherein the primary technology feature of the precision calibration method is that: using a laser speckle image capturing module to capture N frames of laser speckle image from an optical position surface of a rotary encoding body, and then using image comparison libraries and particularly-designed mathematical equations to calculate N number of image displacements, so as to eventually calculate N number of primary variation angles and sub variation angles corresponding to the N frames of laser speckle image. Therefore, after the rotary encoding body is rotated by an arbitrary angle, an immediate angle coordinate can be precisely positioned according to the primary variation angles, the secondary variation angles and the N number of image displacements.

Precision calibration method for high-precise rotary encoder

A quick subpixel absolute positioning device and method are introduced. The method includes the steps of (A) capturing a real-time speckle pattern of a target surface; (B) providing a coarse-precision speckle coordinate pattern and a plurality of fine-precision speckle coordinate patterns, wherein the coarse-precision speckle coordinate pattern and the fine-precision speckle coordinate patterns include a coordinate value; (C) comparing the real-time speckle coordinate pattern with the coarse-precision speckle coordinate pattern by an algorithm and then comparing the real-time speckle coordinate pattern with the fine-precision speckle coordinate patterns to obtain a coordinate value, wherein each said coarse-precision speckle coordinate pattern corresponds to a set of fine-precision speckle coordinate patterns, and the fine-precision speckle coordinate patterns are obtained when the coarse-precision speckle coordinate pattern is captured again and then captured repeatedly according to a fixed fine-precision displacement distance. Accordingly, the subpixel positioning is attained by quick comparison and manifests high precision.

Device and method of quick subpixel absolute positioning

The present invention mainly provides a precision calibration method for being applied in a high-precise rotary encoder system, wherein the primary technology feature of the precision calibration method is that: using a laser speckle image capturing module to capture N frames of laser speckle image from an optical position surface of a rotary encoding body, and then using image comparison libraries and particularly-designed mathematical equations to calculate N number of displacement vectors based on the N frames of laser speckle image, so as to eventually calculate N number of angle coordinates corresponding to the N frames of laser speckle image based on the plurality of displacement vectors. Moreover, a rotation matrix is further proposed and used in this precision calibration method, and used for treating the displacement vectors with a displacement vector transforming process in order to effectively enhance the position precision of the high-precise rotary encoder system.

An actuating apparatus includes a motion driving module rigidly coupled to a platform, a working stage driven by the motion driving module to move relative to the platform, a speckle image capturing module rigidly coupled to the working stage and capable of capturing a speckle image of a sub-region of a reference region of the platform, and a control module operable in a positioning mode, where the control module obtains a current position of the working stage in a coordinate system associated with the platform based on a comparison between the captured speckle image and reference speckle image information that is associated with and unique to the reference region, and controls the motion driving module to drive the working stage toward a target position in the coordinate system based on a difference between the current position and the target position.

Actuating apparatus, actuating system and method for actuating a working stage to move relative to a platform with high-precision positioning capability

A method and system for positioning by using optical speckle are disclosed in this invention. A highly coherent laser light irradiates a positioning template in advance to record optical speckles caused by interference by scattered light beams from the positioning template for establishing a speckle database. Furthermore, a reference point is defined to position each recorded speckle. Therefore, a coordinate with respect to the reference point corresponding to a specified speckle can be used to position a target or applied to distance measurement by the speckle database. The precision of the speckles according to the present invention is within several micrometers. Hence, it can provide high precision positioning.

Method and system for positioning by using optical speckle

A highly sensitive movable touchpad is disclosed in the present invention. It is used for laptop computers and has a slidable template for users to move so that a cursor can be controlled by the touchpad. A resistive or capacitive detecting surface can be applied for detecting users' click, double click, drag, or scroll motion on any point of the surface. Additionally, there is an optical displacement sensor provided under the slidable template for detecting surface information on the back surface of the slidable template. A sequence of images of surface movement are processed by an image processing unit. Then, relative movement information is calculated and sent to an operating system in the computer. The operating system controls the cursor with the relative movement information. The present invention uses edge detectors for dynamically controlling the cursor and calibrating location of the cursor so that positioning of the touchpad is synchronous with the cursor.

Movable touchpad with high sensitivity

An image invariant optical speckle capturing device and method. A highly coherent light is used to illuminate a surface and is scattered by the surface, and is captured from the direction with a &#xb1;10&#xb0; from the angle of specular reflection. A light restrictive module is designed to confine the angular field of view of the sensor, when the speckle capturing device has a relative motion with respect to the surface, the speckle only move on the image but the shape and the intensity are almost keep constant, that is favorable for high accuracy optical pattern recognition and positioning.

Image invariant optical speckle capturing device and method

The present invention relates to a large area undistorted imaging apparatus for light speckles and a method thereof. The large area undistorted imaging apparatus for light speckles comprises a light-emitting device, a light-limiting module, and a sensor. The light-limiting module is adapted in front of the sensor, and includes a plurality of light-limiting members. The light-limiting members are arranged in a one- or two-dimensional array. When the light-emitting device emits light to an object surface, one or more rays of scattered light are produced. By means of the light-limiting module, said one or more rays of scattered light are limited, and a plurality of rays of diffraction light is produced. The plurality of rays of diffraction light within a certain angular field of view produced by a light-limiting member interferes with each other and produces a plurality of undistorted light speckles, and forms an array of light-speckle images on the sensor. Finally, according to the array of light-speckle images, a large-area and undistorted light-speckle pattern is given. Because the light-speckle pattern is undistorted and records the three-dimensional characteristics of the object surface, the undistorted imaging apparatus can be applied to computer mice, finger guiders, smart cards, three-dimensional fingerprint identification apparatuses, a machine tool or precise manipulator positioning systems.

Growing community of inventors

Taipei, Taiwan

Yi-Yuh Hwang