4,523 research outputs found

    A machine learning approach to pedestrian detection for autonomous vehicles using High-Definition 3D Range Data

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    This article describes an automated sensor-based system to detect pedestrians in an autonomous vehicle application. Although the vehicle is equipped with a broad set of sensors, the article focuses on the processing of the information generated by a Velodyne HDL-64E LIDAR sensor. The cloud of points generated by the sensor (more than 1 million points per revolution) is processed to detect pedestrians, by selecting cubic shapes and applying machine vision and machine learning algorithms to the XY, XZ, and YZ projections of the points contained in the cube. The work relates an exhaustive analysis of the performance of three different machine learning algorithms: k-Nearest Neighbours (kNN), NaĂŻve Bayes classifier (NBC), and Support Vector Machine (SVM). These algorithms have been trained with 1931 samples. The final performance of the method, measured a real traffic scenery, which contained 16 pedestrians and 469 samples of non-pedestrians, shows sensitivity (81.2%), accuracy (96.2%) and specificity (96.8%).This work was partially supported by ViSelTR (ref. TIN2012-39279) and cDrone (ref. TIN2013-45920-R) projects of the Spanish Government, and the “Research Programme for Groups of Scientific Excellence at Region of Murcia” of the Seneca Foundation (Agency for Science and Technology of the Region of Murcia—19895/GERM/15). 3D LIDAR has been funded by UPCA13-3E-1929 infrastructure projects of the Spanish Government. Diego Alonso wishes to thank the Spanish Ministerio de EducaciĂłn, Cultura y Deporte, Subprograma Estatal de Movilidad, Plan Estatal de InvestigaciĂłn CientĂ­fica y TĂ©cnica y de InnovaciĂłn 2013–2016 for grant CAS14/00238

    A DUAL-TRIGGER SMART HAND WASHING MACHINE

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    Hand washing is simple and effective in preventing the transmission of infection and sickness in various contexts, including the home, workplace, childcare facilities, and hospitals. It is important to note that contaminated surface like tap heads and manually operated hand sanitizer pose threat to the users of such facility and as such has constituted a global concern due to the emergence of diseases that can be easily transmitted. Hence, this project presents a low-cost automatic hand washing machine with a temperature sensor and counter, triggered by an Ultrasonic sensor and Laser-Light Dependent Resistor (LDR) trip wire that puts ON or OFF the pump and counting at the same time.  The system design was done in two levels, the 3D model and circuit diagram design: firstly, the 3D model design was done with Autodesk Inventor 2017 while the circuit diagram design was done using Fritzing software and simulations performed for both levels. The system was fabricated and evaluated; the result obtained revealed reliable water dispense since the water flow can be activated by either an ultrasonic or laser-LDR sensor, a strong frame at a threshold weight of 166.6 N, and reliable temperature measurement.  The uniqueness of this work is that it combines automated temperature measurement, hand-washing, and counting systems in a single device. Temperature measurement and hand-washing help to prevent disease spread while the counting system assists in recording the number of people using or entering a facility to aid the practice of social distancing as means of curtailing the spread of the diseases

    An Open-Source 7-Axis, Robotic Platform to Enable Dexterous Procedures within CT Scanners

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    This paper describes the design, manufacture, and performance of a highly dexterous, low-profile, 7 Degree-of-Freedom (DOF) robotic arm for CT-guided percutaneous needle biopsy. Direct CT guidance allows physicians to localize tumours quickly; however, needle insertion is still performed by hand. This system is mounted to a fully active gantry superior to the patient's head and teleoperated by a radiologist. Unlike other similar robots, this robot's fully serial-link approach uses a unique combination of belt and cable drives for high-transparency and minimal-backlash, allowing for an expansive working area and numerous approach angles to targets all while maintaining a small in-bore cross-section of less than 16cm216cm^2. Simulations verified the system's expansive collision free work-space and ability to hit targets across the entire chest, as required for lung cancer biopsy. Targeting error is on average <1mm<1mm on a teleoperated accuracy task, illustrating the system's sufficient accuracy to perform biopsy procedures. The system is designed for lung biopsies due to the large working volume that is required for reaching peripheral lung lesions, though, with its large working volume and small in-bore cross-sectional area, the robotic system is effectively a general-purpose CT-compatible manipulation device for percutaneous procedures. Finally, with the considerable development time undertaken in designing a precise and flexible-use system and with the desire to reduce the burden of other researchers in developing algorithms for image-guided surgery, this system provides open-access, and to the best of our knowledge, is the first open-hardware image-guided biopsy robot of its kind.Comment: 8 pages, 9 figures, final submission to IROS 201

    Hope Global -- BEADED PROFILE COUNTER

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    Hope Global runs a Beaded Profile extrusion line that features a polypropylene plastic bead, bonded to a polypropylene non-woven synthetic material. The product is run through a cooling tank, vision inspection system, laser cutter, and finally loaded into boxes where they are weighed and packed. These bonded pieces are shipped to vehicle dealerships around the world as they are used to clip a variety of seat covers to their respective seats. Once the laser cutter executes a pattern of cuts for a given part, that part is counted and sent down a conveyor belt to drop into the J-Box. However, the current counting system has proven to be ineffective, as there is no automatic reset for the product counter on the system. An operator with the task to inspect and package the pieces, at the end of the line, is forced to intervene and frequently neglect their assignment in order to reset the counter on the laser cutter. Due to inefficiencies in the drying process, change is humidity and a fluctuating ambient temperature, Hope Global would like to deviate from the current weighing system as a means to count the final product. Before completing any design work for this solution, patent and literature searches were completed to fully understand methods of previous inventions pertaining to the problem at hand. Thirty design concepts were brainstormed by each team member with sketches and descriptions. Then research techniques ruled out many of them. Through extensive research on previous inventions with this technique, it was determined that using the already efficient laser cutter with a new counting system would be quite complicated. In fact, upon further research and consultation meetings at Hope Global, it was determined that any additional computerized system was inefficient for this solution. It was determined that linking the cutting sequence counter to a simple mechanical system is common in a manufacturing plant and also inexpensive. At this point in the design process it was decided that a diverting system installed at the end of the conveyor belt would be the optimal solution to this manufacturing problem. Upon further inspection of the design specifications and dimensions at the facility, the concepts were narrowed down further and a physical component was designed on SolidWorks and produced with a 3D printer. This design consists of a two angled aluminum walls that guide pieces to the desired location as well as a stabilization platform. A pin axis will be attached to a bracket that is connected to the conveyor belt walls. A motor mounted to a bracket will be linked to the counting system, signaling for a rotation of the guide once the desired count is attained. A multitude of 3D printed models have been created and tested at the facility, with minor design changes necessary after each test. After four testing trials, a final 3D model was printed and a sheet metal prototype was machined at the Hope Global facility. Moving forward, the metal prototype will be adjusted to meet the specifications of the final 3D model and a SVL-201 servo motor will be mounted to an additional bracket and gear-belt system to initiate rotation. This design ensures an autonomous method of counting beaded profile parts at Hope Global with 100 percent accuracy

    Multi-wavelength, multi-beam, photonic based sensor for object discrimination and positioning

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    Over the last decade, substantial research efforts have been dedicated towards the development of advanced laser scanning systems for discrimination in perimeter security, defence, agriculture, transportation, surveying and geosciences. Military forces, in particular, have already started employing laser scanning technologies for projectile guidance, surveillance, satellite and missile tracking; and target discrimination and recognition. However, laser scanning is relatively a new security technology. It has previously been utilized for a wide variety of civil and military applications. Terrestrial laser scanning has found new use as an active optical sensor for indoors and outdoors perimeter security. A laser scanning technique with moving parts was tested in the British Home Office - Police Scientific Development Branch (PSDB) in 2004. It was found that laser scanning has the capability to detect humans in 30m range and vehicles in 80m range with low false alarm rates. However, laser scanning with moving parts is much more sensitive to vibrations than a multi-beam stationary optic approach. Mirror device scanners are slow, bulky and expensive and being inherently mechanical they wear out as a result of acceleration, cause deflection errors and require regular calibration. Multi-wavelength laser scanning represent a potential evolution from object detection to object identification and classification, where detailed features of objects and materials are discriminated by measuring their reflectance characteristics at specific wavelengths and matching them with their spectral reflectance curves. With the recent advances in the development of high-speed sensors and high-speed data processors, the implementation of multi-wavelength laser scanners for object identification has now become feasible. A two-wavelength photonic-based sensor for object discrimination has recently been reported, based on the use of an optical cavity for generating a laser spot array and maintaining adequate overlapping between tapped collimated laser beams of different wavelengths over a long optical path. While this approach is capable of discriminating between objects of different colours, its main drawback is the limited number of security-related objects that can be discriminated. This thesis proposes and demonstrates the concept of a novel photonic based multi-wavelength sensor for object identification and position finding. The sensor employs a laser combination module for input wavelength signal multiplexing and beam overlapping, a custom-made curved optical cavity for multi-beam spot generation through internal beam reflection and transmission and a high-speed imager for scattered reflectance spectral measurements. Experimental results show that five different laser wavelengths, namely 473nm, 532nm, 635nm, 670nm and 785nm, are necessary for discriminating various intruding objects of interest through spectral reflectance and slope measurements. Various objects were selected to demonstrate the proof of concept. We also demonstrate that the object position (coordinates) is determined using the triangulation method, which is based on the projection of laser spots along determined angles onto intruding objects and the measurement of their reflectance spectra using an image sensor. Experimental results demonstrate the ability of the multi-wavelength spectral reflectance sensor to simultaneously discriminate between different objects and predict their positions over a 6m range with an accuracy exceeding 92%. A novel optical design is used to provide additional transverse laser beam scanning for the identification of camouflage materials. A camouflage material is chosen to illustrate the discrimination capability of the sensor, which has complex patterns within a single sample, and is successfully detected and discriminated from other objects over a 6m range by scanning the laser beam spots along the transverse direction. By using more wavelengths at optimised points in the spectrum where different objects show different optical characteristics, better discrimination can be accomplished

    Using Bluetooth Low Energy devices to monitor visitor activity in remote amenity spaces

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    Tracking of pedestrian behaviour, particularly route selection and temporal behaviours, can be difficult to undertake. This is especially true of studies at a community or campus level where the anonymity of pedestrians can be difficult to protect. The introduction of the EU’s General Data Protection Regulations 2016 (GDPR) has increased the complexity of this challenge. Advances in Bluetooth Low Energy (BLE) technology in recent years have increased the potential to monitor human behaviour by tracking and triangulating pedestrians. This paper describes an experiment undertaken along The Great South Wall at the Port of Dublin, which is considered a leading amenity location. Monitoring of visitor behaviour in places of this type can provide valuable information about the use of this and other public resources. The aims of this study were to test two prototypes to: i) determine the direction of participants carrying BLE devices, ii) determine the capabilities of two BLE scanning prototypes, (ESP32 & Raspberry Pi3), iii) test the ability of detecting a small number of BLE devices simultaneously while minimising interference or loss of passers-by data, iv) to investigate the use of a hash encoding scheme to anonymise BLE device identifiers. The findings show that the direction of the visitors to the pier can be detected by correlating the received signal strength indicator (RSSI) from multiple Bluetooth scanning devices and this can work where scanning devices are as close as 10m apart. The locations of the BLE scanners has a slight effect on detecting the RSSI from different distances and the distance between scanners needs to be considered to facilitate accurate measurement of direction. As a pier like the South Wall has only one entrance and exit point, this approach can also be used to determine the length of time spent on the pier. The technical performance of the two BLE scanners was also reviewed and the ESP32 was shown to have significantly lower power consumption with only a slight decrease in performance. Finally, it was shown that the BLE scanners can detect multiple carried BLE devices successfully without interference or loss of data as long as those devices are within range of the BLE scanners
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