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.

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.

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

Robotics ◽  
2013 ◽  
pp. 1482-1499
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.

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 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.

scholarly journals Standard reference values of weight and maximum pressure distribution in healthy adults aged 18–65 years in Germany

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
D. Ohlendorf ◽  
K. Kerth ◽  
W. Osiander ◽  
F. Holzgreve ◽  
L. Fraeulin ◽  
...  
Keyword(s):  
Body Weight ◽  
Pressure Distribution ◽  
Reference Values ◽  
Effect Size ◽  
Weight Distribution ◽  
Age Groups ◽  
Healthy Adults ◽  
The Body ◽  
Maximum Pressure ◽  
Left And Right

Abstract Background The aim of this study was to collect standard reference values of the weight and the maximum pressure distribution in healthy adults aged 18–65 years and to investigate the influence of constitutional parameters on it. Methods A total of 416 healthy subjects (208 male / 208 female) aged between 18 and 65 years (Ø 38.3 ± 14.1 years) participated in this study, conducted 2015–2019 in Heidelberg. The age-specific evaluation is based on 4 age groups (G1, 18–30 years; G2, 31–40 years; G3, 41–50 years; G4, 51–65 years). A pressure measuring plate FDM-S (Zebris/Isny/Germany) was used to collect body weight distribution and maximum pressure distribution of the right and left foot and left and right forefoot/rearfoot, respectively. Results Body weight distribution of the left (50.07%) and right (50.12%) foot was balanced. There was higher load on the rearfoot (left 54.14%; right 55.09%) than on the forefoot (left 45.49%; right 44.26%). The pressure in the rearfoot was higher than in the forefoot (rearfoot left 9.60 N/cm2, rearfoot right 9.51 N/cm2/forefoot left 8.23 N/cm2, forefoot right 8.59 N/cm2). With increasing age, the load in the left foot shifted from the rearfoot to the forefoot as well as the maximum pressure (p ≤ 0.02 and 0.03; poor effect size). With increasing BMI, the body weight shifted to the left and right rearfoot (p ≤ 0.001, poor effect size). As BMI increased, so did the maximum pressure in all areas (p ≤ 0.001 and 0.03, weak to moderate effect size). There were significant differences in weight and maximum pressure distribution in the forefoot and rearfoot in the different age groups, especially between younger (18–40 years) and older (41–65 years) subjects. Discussion Healthy individuals aged from 18 to 65 years were found to have a balanced weight distribution in an aspect ratio, with a 20% greater load of the rearfoot. Age and BMI were found to be influencing factors of the weight and maximum pressure distribution, especially between younger and elder subjects. The collected standard reference values allow comparisons with other studies and can serve as a guideline in clinical practice and scientific studies.

scholarly journals PHYSICAL DISTANCING ALARM SYSTEM BASED ON PROXIMITY SENSOR AND MICROCONTROLLER

2021 ◽  
Vol 4 (2) ◽  
pp. 79
Author(s):  
Elfi Yuliza ◽  
Riska Ekawita ◽  
Vionita Vionita ◽  
Muhammad Khafid Fauzi ◽  
Vera Fuspita Sari ◽  
...  
Keyword(s):  
System Performance ◽  
The Other ◽  
Alarm System ◽  
Best Effort ◽  
Interaction Distance ◽  
Measurement Results ◽  
Identity Card ◽  
Left And Right ◽  
Distance Sensor ◽  
User Friendly

Keeping an interaction distance between 1 to 2 m is one of the health protocols during the COVID-19 pandemic. This attempt was made to reduce the spread of the Coronavirus. On the other hand, this health protocol activity is often overlooked, whether intentionally or not. According to the mechanism of the Coronavirus spreading in the form of droplets that comes out during communication, sneezing, or coughing, maintaining distance can be the best effort to minimize the transmission of this virus. Therefore, the availability of a simple, accurate and user-friendly physical distancing alarm system could be a solution in the implementation of this health protocol. In this study, a prototype of a physical distancing alarm based on a distance sensor and a microcontroller in the form of an identity card was developed. Several steps are conducted in developing of this system, namely designing the instrumentation system and testing the performance of the system. System performance is tested through variations in the distance and angle of the objects. The measurement results show that the system can detect objects in front of the sensor up to a distance of 2.8m and an angle of  for a distance of 1m. The measurement using different angles of objects was performed for objects on the left and right sides of the sensor. In addition, a warning alarm will be on when the distance of the object exceeds the allowed distance.  

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.

scholarly journals Speed Calibration and Traceability for Train-Borne 24 GHz Continuous-Wave Doppler Radar Sensor

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1230
Author(s):  
Lei Du ◽  
Qiao Sun ◽  
Jie Bai ◽  
Xiaolei Wang ◽  
Tianqi Xu
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Single Channel ◽  
Full Range ◽  
Calibration Method ◽  
Simulation System ◽  
Radar Sensor ◽  
Dual Channel ◽  
Calibration Methods ◽  
24 Ghz

The 24 GHz continuous-wave (CW) Doppler radar sensor (DRS) is widely used for measuring the instantaneous speed of moving objects by using a non-contact approach, and has begun to be used in train-borne movable speed measurements in recent years in China because of its advanced performance. The architecture and working principle of train-borne DRSs with different structures including single-channel DRSs used for freight train speed measurements in railway freight dedicated lines and dual-channel DRSs used for speed measurements of high-speed and urban rail trains in railway passenger dedicated lines, are first introduced. Then, the disadvantages of two traditional speed calibration methods for train-borne DRS are described, and a new speed calibration method based on the Doppler shift signal simulation by imposing a signal modulation on the incident CW microwave signal is proposed. A 24 GHz CW radar target simulation system for a train-borne DRS was specifically realized to verify the proposed speed calibration method for a train-borne DRS, and traceability and performance evaluation on simulated speed were taken into account. The simulated speed range of the simulation system was up to (5~500) km/h when the simulated incident angle range was within the range of (45 ± 8)°, and the maximum permissible error (MPE) of the simulated speed was ±0.05 km/h. Finally, the calibration and uncertainty evaluation results of two typical train-borne dual-channel DRS samples validated the effectiveness and feasibility of the proposed speed calibration approach for a train-borne DRS with full range in the laboratory as well as in the field.

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