A laser tracking system is employed for measuring robot arm's tip with high accuracy. Geometric parameters in a robot kinematic model are calibrated by minimizing errors between measured positions and predicted ones based on the model. Residual errors caused by non-geometric parameters are further reduced by using neural networks, realizing high positioning accuracy of sub-millimeter order. To speed up the calibration process, the smaller number of measuring points is preferable. Optimal measuring points, which realize high positioning accuracy with small point number, are selected using genetic algorithm (GA).

Improvement of robot accuracy by calibrating kinematic model using a laser tracking system-compensation of non-geometric errors using neural networks and selection of optimal measuring points using genetic algorithm-

The invention discloses a device for automatically marking an additional external axis robot based on laser tracking measurement and a method thereof The device comprises a system platform, a target flange, target mounting holes, a robot guide rail, a robot, a laser tracker, a workpiece, a numerical control finish machining machine tool, a three-coordinate numerical control locator, and an uppercomputer, wherein the system platform is provided with 9 target mounting holes processed by the numerical control finish machining machine tool, the three-coordinate numerical control locator and therobot guide rail; the workpiece is fixed on the three-coordinate numerical control locator; the robot is arranged on the robot guide rail; the target flange is arranged on the robot; 6 target mounting holes are arranged on the target flange; the targets are arranged on the target mounting holes; the numerical control finish machining machine tool, the laser tracker and the upper computer are installed at the outer side of the system platform The device has the advantages that: (1) the device is capable of automatically marking the robot coordinate system with the additional external axis; (2) the device is high in marking precision and reliable in marking result; and (3) the device is further simple in marking operation and high in efficiency

Device for automatically marking additional external axis robot based on laser tracking measurement and method thereof

Calibration of Kinematic Parameters of Robot Arm Using Laser Tracking System: Compensation for Non-Geometric Errors by Neural Networks and Selection of Optimal Measuring Points by Genetic Algorithm

A shape measurement device includes: a stage for loading a subject for measurement; an imaging section that forms an image of the subject for measurement; and a shifting section that implements relative shifting between the imaging section and the subject for measurement to shift the imaging section to a position corresponding to a portion on the subject for measurement which is to be measured, and the shifting section implements the relative shifting by shifting the imaging section without shifting the stage.

Shape measurement device

The invention provides an attitude sensor mounting offset correction method The method comprises the following offset angle measurement process: fixedly arranging a mounting platform on which an attitude sensor is mounted on a horizontal rotary platform, controlling the horizontal rotary platform to rotate at a constant speed, and keeping the mounting platform and the horizontal rotary platform relative rest; acquiring pitch angular velocity omegaX0 and yaw angular velocity omegaZ0 outputted by a gyroscope in the attitude sensor when the horizontal rotary platform rotates at a constant speed; and calculating the included angle theta between the pitch axis of the gyroscope and the pitch axis of the mounting platform according to a formula theta=arctan(-omegaX0/omegaZ0), and storing the included angle theta as the offset angle The method also comprises a step of correcting the angular velocity outputted by the gyroscope according to the offset angle The attitude sensor mounting offset correction method provided by the invention has the advantages of low cost, high precision and reliability, can effectively correct mounting offset of the attitude sensor, and solves the problems caused by attitude sensor mounting offset in the prior art

Attitude sensor mounting offset correction method

PROBLEM TO BE SOLVED: To realize a real-time, non-contact, and highly precise attitude measurement free from limitation of measuring range by arranging a piezoelectric rotary gyro at the fingertip of a robot SOLUTION: An articulated robot system 100 is provided with a piezoelectric element rotary gyro 50 which consists of, for example, two gyro units each consisting of two sets of piezoelectric element-made benders and detects the angular velocity around three axes and acceleration in three axial directions of the fingertip of a robot 10 The detected angle speed is arithmetically processed by a signal processing box 55, whereby the attitude change from the initial attitude can be determined The static and dynamic precision certification with the assumption of the natural movement of the robot with respect to the gyro 50 is performed, for example, by use of a turntable with three degrees of freedom as calibration reference, and a laser tracking system, for example, is used for the calibration of dimensional error or mounting error of the turntable itself

Articulated robot system with function of measuring attitude, method and system for certifying measuring precision of gyro by use of turntable for calibration reference, and device and method for calibrating turntable formed of n-axes

For the purpose of realizing not only positioning but also orientating accuracy of a robot, a position and orientation calibration method is newly proposed and applied to a 6-DOF articulated robot (PUMA 560). The existence of gear transmission errors and gear backlashes of the 4-6th axes of this robot is detected by using a high precision gyroscope and it is proved that these non-geometric errors cause the orientation error of robot arm's tip. A position and orientation measuring system using both a laser tracking system and this gyroscope is proposed. A calibration method, which uses both position and orientation data and considers non-geometric errors of 4-6th axes as parameters to be calibrated in the forward kinematics model, is proposed. The positioning accuracy of 0.2mm and roll, pitch, yaw orientating accuracy of (0.17°, 0.10°, 0.10°), which is near the limit value of calibration predicted by the orientating repeatability, are successfully achieved and it is experimentally proved that the proposed measuring system and the calibration method are very effective for improving the orientating accuracy while keeping the high positioning accuracy. The optimal weights of position and orientation data in the least squares estimation process of parameters are also discussed.

ジャイロを用いたロボットの姿勢計測に関する研究(第2報)-レーザトラッキングシステムとジャイロを併用したロボットの位置・姿勢キャリブレーション手法の提案-

Aiming at realizing off-line programming, many researches of improving robot's accuracy by calibrating the kinematic parameters of a robot are being carried out now. For an effective calibration it is necessary to measure the position of the tip of a robot arm precisely in a comparatively wide area. Although a laser tracking system is regarded as the most practical measuring system for this purpose in ISO 9283, there is no report yet which actually applies this system to the robot calibration. In this paper a 6-DOF articulated robot is calibrated by using a laser tracking system according to the joint axis estimating method and the effectiveness of this system is certified. A method of estimating the accuracy which refers to the robot base coordinate system is proposed. It is proved experimentally that the accuracy of the robot before calibration is worse than 3mm. The robot after calibration is positioned to the limited grid which is in the area near the initial pose of the calibration and to the wide grid. The accuracy in the limited grid is improved to be 0.27mm by the calibration, however the accuracy in the wide grid is worse compared with that in the limited grid. From this result it is proved that the joint axis estimating method is not so effective except for the neighborhood of the initial pose.

https://www.jstage.jst.go.jp/article/jjspe1986/65/7/65_7_1035/_pdf

レーザトラッキングシステムを用いたロボットのキャリブレーションに関する研究(第1報) -ロボットの絶対位置決め精度の検証と対偶軸同定法の問題点の指摘-

超音波による口ポットの3次元位置・姿勢計測 (第3報)

Because the visually impaired desire to know not only color of the 1 point but also whole color on the object, we developed a color discrimination system by the presentation of the sound which enable the blind to recognize the color and its change. While the blind scans the surface of a target object with this system, it continuously makes sound corresponding to surface colors. The problem is the mapping between color and sound for the blind to learn easily and to get the color condition shortly. In this paper, we propose the Shepard Tone Method (STM) and the Trio Ensemble Method (TEM) as this mapping.

好承神谷

Papers

Articulated robot system with function of measuring attitude, method and system for certifying measuring precision of gyro by use of turntable for calibration reference, and device and method for calibrating turntable formed of n-axes

ジャイロを用いたロボットの姿勢計測に関する研究(第2報)-レーザトラッキングシステムとジャイロを併用したロボットの位置・姿勢キャリブレーション手法の提案-

レーザトラッキングシステムを用いたロボットのキャリブレーションに関する研究(第1報) -ロボットの絶対位置決め精度の検証と対偶軸同定法の問題点の指摘-

超音波による口ポットの3次元位置・姿勢計測 (第3報)

視覚障害者用の携帯型色認識装置の開発 (第2報): 色模様認識のための色と音のマッピング

好承 神谷

Papers

Articulated robot system with function of measuring attitude, method and system for certifying measuring precision of gyro by use of turntable for calibration reference, and device and method for calibrating turntable formed of n-axes

ジャイロを用いたロボットの姿勢計測に関する研究(第2報)-レーザトラッキングシステムとジャイロを併用したロボットの位置・姿勢キャリブレーション手法の提案-

レーザトラッキングシステムを用いたロボットのキャリブレーションに関する研究(第1報) -ロボットの絶対位置決め精度の検証と対偶軸同定法の問題点の指摘-

超音波による口ポットの3次元位置・姿勢計測 (第3報)

視覚障害者用の携帯型色認識装置の開発 (第2報): 色模様認識のための色と音のマッピング

好承神谷