scholarly journals A Laser-Based Direct Cable Length Measurement Sensor for CDPRs

Robotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 60
Author(s):  
Christoph Martin ◽  
Marc Fabritius ◽  
Johannes T. Stoll ◽  
Andreas Pott
Keyword(s):  
Mechanical Design ◽  
Parallel Robots ◽  
Length Measurement ◽  
Cable Length ◽  
Measurement Sensor ◽  
Important Research Topic ◽  
Measurement Principle ◽  
Laser Distance Sensor ◽  
Distance Sensor ◽  
The One

Accuracy improvement is an important research topic in the field of cable-driven parallel robots (*CDPRS). One reason for inaccuracies of *CDPRS are deviations in the cable lengths. Such deviations can be caused by the elongation of the cable due to its elasticity or creep behavior. For most common *CDPRS, the cable lengths are controlled using motor encoders of the winches, without feedback about the actual elongation of the cables. To address this problem, this paper proposes a direct cable length measurement sensor based on a laser distance sensor. We present the mechanical design, the first prototype and an experimental evaluation. As a result, the measurement principle works well and the accuracy of the measured cable lengths is within −2.32 mm to +1.86 mm compared to a range from −5.19 mm to +6.02 mm of the cable length set with the motor encoders. The standard deviation of the cable length error of the direct cable length measurement sensor is 58% lower compared to the one set with the motor encoders. Equipping all cables of the cable robot with direct cable length measurement sensors results in the possibility to correct cable length deviations and thus increase the accuracy of *CDPRS. Furthermore, it enables new possibilities like the automatic recalibration of the home pose.

Accuracy Improvement of Terminal Voltage Self-coupled Laser Distance Sensor

2020 ◽  
Vol 140 (11) ◽  
pp. 1264-1269
Author(s):  
Tatsuya Ohba ◽  
Daisuke Mizushima ◽  
Keishiro Goshima ◽  
Norio Tsuda ◽  
Jun Yamada
Keyword(s):  
Accuracy Improvement ◽  
Terminal Voltage ◽  
Laser Distance Sensor ◽  
Distance Sensor

scholarly journals Laser Distance Sensors Evaluation for Geomatics Researches

2020 ◽  
pp. 1831
Author(s):  
Abbas Zedan Khalaf ◽  
Bashar H Alyasery
Keyword(s):  
Reference Values ◽  
3D Modeling ◽  
Full Range ◽  
Calibration Method ◽  
Additive Error ◽  
Statistical Indicator ◽  
Laser Distance Sensor ◽  
Left And Right ◽  
Distance Sensor

In this study, an approach inspired by a standardized calibration method was used to test a laser distance meter (LDM). A laser distance sensor (LDS) was tested with respect to an LDM and then a statistical indicator explained that the former functions in a similar manner as the latter. Also, regression terms were used to estimate the additive error and scale the correction of the sensors. The specified distance was divided into several parts with percent of longest one and observed using two sensors, left and right. These sensors were evaluated by using the regression between the measured and the reference values. The results were computed using MINITAB 17 package software and excel office package. The accuracy of the results in this work was ± 4.4mm + 50.89 ppm and ± 4.96mm + 99.88 ppm for LDS1 and LDS2, respectively, depending on the LDM accuracy which was computed to the full range (100 m). Using these sensors can be very effective for industrial, 3D modeling purposes, and many other applications, especially that it is inexpensive and available in many versions.

scholarly journals Long-Exposure RGB Photography with a Fixed Stand for the Measurement of a Trajectory of a Dynamic Impact Device in Real Scale

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6818
Author(s):  
Ľudovít Kovanič ◽  
Ľubomír Ambriško ◽  
Daniela Marasová ◽  
Peter Blišťan ◽  
Tomáš Kasanický ◽  
...  
Keyword(s):  
Impact Resistance ◽  
Dynamic Impact ◽  
Long Duration ◽  
Conveyor Belts ◽  
Laser Distance Sensor ◽  
Novel Method ◽  
Distance Sensor ◽  
Reference Measurements ◽  
Real Scale

The present manuscript proposes a novel method for the measurement of a trajectory of a falling impact hammer in the dynamic loading of conveyor belts and the determination of their impact resistance. The proposed method has been experimentally tested and the results of the measurements are presented in this manuscript. The proposed method is based on the long-exposure photography with a long-duration opened shutter of the Nikon D5000 DSLR camera. Results of the experimental research were compared with direct reference measurements performed using the L-GAGE LT3 laser distance sensor. Differences between values, obtained by the new method and by the reference measurements were up to ±3 mm. The standard deviation identified in all the experiments was 1 mm.

Self-Calibration of Eye-to-Hand and Workspace for Mobile Service Robot

2012 ◽  
pp. 229-246
Author(s):  
Jwu-Sheng Hu ◽  
Yung-Jung Chang
Keyword(s):  
Visual Information ◽  
Calibration Method ◽  
Industrial Robots ◽  
Service Robots ◽  
Service Robot ◽  
Mobile Service ◽  
Robot Arm ◽  
Self Calibration ◽  
Laser Distance Sensor ◽  
Distance Sensor

The geometrical relationships among robot arm, camera, and workspace are important to carry out visual servo tasks. For industrial robots, the relationships are usually fixed and well calibrated by experienced operators. However, for service robots, particularly in mobile applications, the relationships might be changed. For example, when a mobile robot attempts to use the visual information from environmental cameras to perform grasping, it is necessary to know the relationships before taking actions. Moreover, the calibration should be done automatically. This chapter proposes a self-calibration method using a laser distance sensor mounted on the robot arm. The advantage of the method, as compared with pattern-based one, is that the workspace coordinate is also obtained at the same time using the projected laser spot. Further, it is not necessary for the robot arm to enter the view scope of the camera for calibration. This increases the safety when the workspace is unknown initially.

Improvement on Yield of Anisotropic Conductive Film Attach Process in TFT-LCD Module Using Taguchi Method

2010 ◽  
Vol 443 ◽  
pp. 717-722
Author(s):  
Jian Long Kuo ◽  
Kai Lun Chao ◽  
Chung Hao Hsieh
Keyword(s):  
Taguchi Method ◽  
Mechanical Design ◽  
Quality Characteristic ◽  
Design Parameters ◽  
Manufacturing Cost ◽  
Anisotropic Conductive Film ◽  
Important Concern ◽  
Conductive Film ◽  
Product Competition ◽  
The One

Anisotropic Conductive Film (ACF) is one of the important materials in LCM (Liquid Crystal Module) process, it is used in bonding process to make the driving circuit conductive. Because the price of TFT-LCD is much lower than before in recent years, the ACF cost has higher ratio in manufacture cost. The conventional long bar ACF attach unit is changed to short bar ACF attach unit in new bonding equipment. However, the new type machine was not optimized in process and mechanical design. Therefore, the failure rate of ACF attach process is much higher than the one of conventional method. This wastes the material and rework cost is also invisible. How to make the manufacturing cost down effectively and promote the product quality will be the important concern to keep the product competition. Therefore, the Taguchi method is used to analyze the problem. The ACF attach yield rate is selected to be objective function for optimization. By the optimization of quality characteristic using Taguchi method, the plasma clean speed, ACF peeling speed and ACF cutter spring setting are studied to optimize the design parameters.

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