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1 – 10 of over 4000Ravinder Singh and Kuldeep Singh Nagla
An efficient perception of the complex environment is the foremost requirement in mobile robotics. At present, the utilization of glass as a glass wall and automated transparent…
Abstract
Purpose
An efficient perception of the complex environment is the foremost requirement in mobile robotics. At present, the utilization of glass as a glass wall and automated transparent door in the modern building has become a highlight feature for interior decoration, which has resulted in the wrong perception of the environment by various range sensors. The perception generated by multi-data sensor fusion (MDSF) of sonar and laser is fairly consistent to detect glass but is still affected by the issues such as sensor inaccuracies, sensor reliability, scan mismatching due to glass, sensor model, probabilistic approaches for sensor fusion, sensor registration, etc. The paper aims to discuss these issues.
Design/methodology/approach
This paper presents a modified framework – Advanced Laser and Sonar Framework (ALSF) – to fuse the sensory information of a laser scanner and sonar to reduce the uncertainty caused by glass in an environment by selecting the optimal range information corresponding to a selected threshold value. In the proposed approach, the conventional sonar sensor model is also modified to reduce the wrong perception in sonar as an outcome of the diverse range measurement. The laser scan matching algorithm is also modified by taking out the small cluster of laser point (w.r.t. range information) to get efficient perception.
Findings
The probability of the occupied cells w.r.t. the modified sonar sensor model becomes consistent corresponding to diverse sonar range measurement. The scan matching technique is also modified to reduce the uncertainty caused by glass and high computational load for the efficient and fast pose estimation of the laser sensor/mobile robot to generate robust mapping. These stated modifications are linked with the proposed ALSF technique to reduce the uncertainty caused by glass, inconsistent probabilities and high load computation during the generation of occupancy grid mapping with MDSF. Various real-world experiments are performed with the implementation of the proposed approach on a mobile robot fitted with laser and sonar, and the obtained results are qualitatively and quantitatively compared with conventional approaches.
Originality/value
The proposed ASIF approach generates efficient perception of the complex environment contains glass and can be implemented for various robotics applications.
Details
Keywords
Ravinder Singh and Kuldeep Singh Nagla
An autonomous mobile robot requires efficient perception of the environment to perform various tasks in a challenging environment. The precise sensory information from the range…
Abstract
Purpose
An autonomous mobile robot requires efficient perception of the environment to perform various tasks in a challenging environment. The precise sensory information from the range sensors is required to accomplish prerequisites, such as SLAM, path planning and localization. But the accuracy and precision of the sensors become unreliable in harsh environmental conditions because of the effect of rain, dust, humidity, fog and smoke. The purpose of this paper is to generate robust mapping of the environment in harsh environmental conditions.
Design/methodology/approach
This paper presents a novel technique, averaging data with short range selection (ADWSRS), to reduce the effect of harsh environmental (rain, wind, humidity, etc.) conditions on sensory information (range) to generate reliable grid mapping. The sensory information on laser and sonar sensors in terms of probability values (occupied/unoccupied cell) in generating grid maps are fused after passing through two newly designed pre-processing filters: laser averaging filter and short range selection filter. This proposed approach relies on various aspects such as averaging laser data analogous to current pose of the sensor, selection of short range with respect to threshold value to remove the effect of specular reflection/crosstalk of sonar and a newly designed apparatus in which dirt cover (glass cover) and air blower are coupled to remove the influence of dirt, rain and humidity.
Findings
This proposed approach is tested in different environmental conditions, and to verify the consistency of the proposed approach, qualitative and quantitative analyses are carried out, which shows 42.5 per cent improvement in the probability value of occupied cells in the generated grid map.
Originality/value
The proposed ADWSRS approach reduced the effect of harsh environmental conditions such as fog, rain and smoke to generate efficient mapping of the environment, which may be implemented in diverse applications such as autonomous navigation, localization, path planning and mapping.
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Keywords
Walter Pastorius and Mike Snow
This paper aims to use 3D laser sensors to collect high‐density data that are required for defect detection and localization at high‐production rates in manufacturing facilities.
Abstract
Purpose
This paper aims to use 3D laser sensors to collect high‐density data that are required for defect detection and localization at high‐production rates in manufacturing facilities.
Design/methodology/approach
The high‐speed sensors use Ethernet communications to transport large amounts of data and resolve any synchronization issues.
Findings
Modern laser sensor technology provides the ability to detect and quantify defects in high‐volume manufacturing, wherever defects are located. Laser line sensors provide high speed, high‐density data for full surface inspection. Synchronization and communications issues are simplified by the FireSync™ platform, making system integration straightforward, and maximizing reliability.
Originality/value
This paper provides detailed 3D data at high speed and uses multiple (binocular) scanners to overcome problems of occlusion.
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Keywords
Xinyu Zhang and Liling Ge
A multi-laser sensors-based measurement instrument is proposed for the measurement of geometry errors of a differential body and quality evaluation. This paper aims to discuss the…
Abstract
Purpose
A multi-laser sensors-based measurement instrument is proposed for the measurement of geometry errors of a differential body and quality evaluation. This paper aims to discuss the aforementioned idea.
Design/methodology/approach
First, the differential body is set on a rotation platform before measuring. Then one laser sensor called as “primary sensor”, is installed on the intern of the differential body. The spherical surface and four holes on the differential body are sampled by the primary sensor when the rotation platform rotates one revolution. Another sensor called as “secondary sensor”, is installed above to sample the external cylinder surface and the planar surface on the top of the differential body, and the external cylinder surface and the planar surface are high in manufacturing precision, which are used as datum surfaces to compute the errors caused by the motion of the rotation platform. Finally, the sampled points from the primary sensor are compensated to improve the measurement accuracy.
Findings
A multi-laser sensors-based measurement instrument is proposed for the measurement of geometry errors of a differential body. Based on the characteristics of the measurement data, a gradient image-based method is proposed to distinguish different objects from laser measurement data. A case study is presented to validate the measurement principle and data processing approach.
Research limitations/implications
The study investigates the possibility of correction of sensor data by the measurement results of multiple sensors to improving measurement accuracy. The proposed technique enables the error analysis and compensation by the geometric correlation relationship of various features on the measurand.
Originality/value
The proposed error compensation principle by using multiple sensors proved to be useful for the design of new measurement device for special part inspection. The proposed approach to describe the measuring data by image also is proved to be useful to simplify the measurement data processing.
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This paper aims to propose a hand–eye calibration method of arc welding robot and laser vision sensor by using semidefinite programming (SDP).
Abstract
Purpose
This paper aims to propose a hand–eye calibration method of arc welding robot and laser vision sensor by using semidefinite programming (SDP).
Design/methodology/approach
The conversion relationship between the pixel coordinate system and laser plane coordinate system is established on the basis of the mathematical model of three-dimensional measurement of laser vision sensor. In addition, the conversion relationship between the arc welding robot coordinate system and the laser vision sensor measurement coordinate system is also established on the basis of the hand–eye calibration model. The ordinary least square (OLS) is used to calculate the rotation matrix, and the SDP is used to identify the direction vectors of the rotation matrix to ensure their orthogonality.
Findings
The feasibility identification can reduce the calibration error, and ensure the orthogonality of the calibration results. More accurate calibration results can be obtained by combining OLS + SDP.
Originality/value
A set of advanced calibration methods is systematically established, which includes parameters calibration of laser vision sensor and hand–eye calibration of robots and sensors. For the hand–eye calibration, the physics feasibility problem of rotating matrix is creatively put forward, and is solved through SDP algorithm. High-precision calibration results provide a good foundation for future research on seam tracking.
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Ravinder Singh and Kuldeep Singh Nagla
Accurate perception of the environment using range sensors such as laser scanner, SONAR, infrared, vision, etc., for the application, such as path planning, localization…
Abstract
Purpose
Accurate perception of the environment using range sensors such as laser scanner, SONAR, infrared, vision, etc., for the application, such as path planning, localization, autonomous navigation, simultaneously localization and mapping, is a highly challenging area. The reliability of the perception by range sensors relies on the sensor accuracy, precision, sensor model, sensor registration, resolution, etc. Laser scanner is even though accurate and precise but still the efficient and consistent mapping of the environment is yet to be attained because laser scanner gives error as the extrinsic and intrinsic parameters varied which cause specular reflection, refraction, absorption, etc., of the laser beam. The paper aims to discuss this issue.
Design/methodology/approach
This paper presents an error analysis in sensory information of laser scanner due to the effect of varying the scanning angle with respect to the optical axis and surface reflectivity or refractive index of the targets. Uncertainties caused by these parameters are reduced by proposing a new technique, tilt mounting system (TMS) with designed filters of tilting the angular position of a laser scanner with the best possible selection of range and scanning angle for the robust occupancy grid mapping. Various experiments are performed in different indoor environments, and the results are validated after the implementation of the TMS approach with designed filters.
Findings
After the implementation of the proposed TMS approach with filters, the errors in the laser grid map are reduced by 15.6 percent, which results in 62.5 percent reduction in the collision of a mobile robot during autonomous navigation in the laser grid map.
Originality/value
The TMS approach with designed filter reduces the effect of variation in intrinsic and extrinsic parameters to generate efficient laser occupancy grid map to achieve collision-free autonomous navigation.
Details
Keywords
Ravinder Singh and Kuldeep Singh Nagla
Modern service robots are designed to work in a complex indoor environment, in which the robot has to interact with the objects in different ambient light intensities (day light…
Abstract
Purpose
Modern service robots are designed to work in a complex indoor environment, in which the robot has to interact with the objects in different ambient light intensities (day light, tube light, halogen light and dark ambiance). The variations in sudden ambient light intensities often cause an error in the sensory information of optical sensors like laser scanner, which reduce the reliability of the sensor in applications such as mapping, path planning and object detection of a mobile robot. Laser scanner is an optical sensor, so sensory information depends upon parameters like surface reflectivity, ambient light condition, texture of the targets, etc. The purposes of this research are to investigate and remove the effect of variation in ambient light conditions on the laser scanner to achieve robust autonomous mobile robot navigation.
Design/methodology/approach
The objective of this study is to analyze the effect of ambient light condition (dark ambiance, tube light and halogen bulb) on the accuracy of the laser scanner for the robust autonomous navigation of mobile robot in diverse illumination environments. A proposed AIFA (Adaptive Intensity Filter Algorithm) approach is designed in robot operating system (ROS) and implemented on a mobile robot fitted with laser scanner to reduce the effect of high-intensity ambiance illumination of the environment.
Findings
It has been experimentally found that the variation in the measured distance in dark is more consistent and accurate as compared to the sensory information taken in high-intensity tube light/halogen bulbs and in sunlight. The proposed AIFA approach is implement on a laser scanner fitted on a mobile robot which navigates in the high-intensity ambiance-illuminating complex environment. During autonomous navigation of mobile robot, while implementing the AIFA filter, the proportion of cession with the obstacles is reduce to 23 per cent lesser as compared to conventional approaches.
Originality/value
The proposed AIFA approach reduced the effect of the varying ambient light conditions in the sensory information of laser scanner for the applications such as autonomous navigation, path planning, mapping, etc. in diverse ambiance environment.
Details
Keywords
Chunxia Huang, Qixin Cao, Zhuang Fu and Chuntao Leng
This paper sets out to propose a wafer prealigner based on multi‐sensor integration and an effective prealignment method implemented on it.
Abstract
Purpose
This paper sets out to propose a wafer prealigner based on multi‐sensor integration and an effective prealignment method implemented on it.
Design/methodology/approach
The wafer and notch eccentricities, on which wafer prealignment is based, are calculated with the peripheral data of the wafer detected by a laser displacement sensor and a transmission laser sensor by means of barycenter acquiring algorithm in a one‐particle system.
Findings
The center and notch prealignment precisions of the system are, respectively, ±1.5 μm and ±30 μrad. Experimentation has proved the validity and effectiveness of the system.
Practical implications
The wafer prealigner is a subsystem of the lithography in the semiconductor industry. The prealignment algorithm can be implemented in any object with random figures.
Originality/value
The periphery of the wafer is detected by a high‐precision laser displacement sensor and a low‐cost transmission laser sensor instead of a CCD linear sensor used by traditional wafer prealigners, which saves the space occupation of the structure and enhances the systematic prealignment precision. Using barycenter acquiring algorithm in a one‐particle system to calculate the wafer and notch eccentricities is effective and valid.
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The paper aims to provide a review of how innovations in laser, acoustics, radar, magnetic and other sensor technologies are aiding in making unmanned vehicles more autonomous.
Abstract
Purpose
The paper aims to provide a review of how innovations in laser, acoustics, radar, magnetic and other sensor technologies are aiding in making unmanned vehicles more autonomous.
Design/methodology/approach
In‐depth interviews are carried out with exhibitors of sensors at the AUVSI exhibition.
Findings
Innovations in infrared, laser, acoustics, magnetic and other sensor technologies are helping unmanned vehicles better meet the challenge of an ever‐increasing range of applications in military, law enforcement, and commercial applications as well as agriculture, fishing and rescue operations.
Practical implications
These sensor innovations will help make robot applications of all types more autonomous, easier to create and more cost effective in unmanned as well as manufacturing, logistics, medical and other applications.
Originality/value
The paper provides an insight into some of the latest in laser, radar, acoustic, magnetic, accelerometer, vision and gyro sensors and how they are helping address robotic applications that one might have seen if they had been on the exhibition floor at the Las Vegas unmanned vehicle show (AUVSI) in 2012.
Looks at the use of non‐contact displacement and vibration sensors and notes their value for difficult sensing measurements. Mentions various situations which may dictate the use…
Abstract
Looks at the use of non‐contact displacement and vibration sensors and notes their value for difficult sensing measurements. Mentions various situations which may dictate the use of a non‐contact sensor. Focuses on fibre‐optic sensors and laser triangulation sensors. Concludes that practical uses for such devices are rapidly expanding.
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