ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: Sensor: Flash LadarOutlineReference listTo explore further (survival pointers of web references etc)OverviewSlide 6Slide 7Design ConsiderationsSlide 9Design Considerations: AccuracySlide 11Applications: Head TrackingApplications: Robotic VisionApplications: Human-Machine InteractionApplications: Automatic Target RecognitionIssues: NoiseIssues: AliasingIssues: Ambient LightIssues: Saturation versus No DataWhere To BuyECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Assignment#01: Literature Survey on Sensors and Actuators Topic: Sensor: Flash Ladar3/9/2007Prepared by: Brandon BoldtDept. of Electrical and Computer Engineering Utah State University(Electrical and Computer Engineering Dept.)01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-2Outline –Reference list–To probe further–Overview–Design Considerations–Applications–Issues–Where to Buy01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference list•S. B. Gokturk, H. Yalcin, and C. Bamji, “A time-of-flight depth sensor – system description, issues and solutions,” 2004 Conference on Computer Vision and Pattern Recognition Workshop.•S. B. Gokturk and C. Tomasi, “3d head tracking based on recognition and interpolation using a time-of-flight depth sensor,” 2004 IEEE Computer Society Conference on Computer Vision and Pattern Recognition.•Beeck, Wilinski, Fehn, Kauff, Ijsselsteijn, Pollefeys, Gool, Ofek, and Sexton, “Towards an optimized 3D broadcast chain.”•Anderson, Herman, and Kelly, “Experimental Characterization of Commercial Flash Ladar Devices”, The Robotics Institute01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To explore further (survival pointers of web references etc) •http://en.wikipedia.org/wiki/LadarA wikipedia entry for Ladar•http://www.canesta.com/html/technical_papers.htmCanesta's repository of technical papers•http://www.csem.ch/fs/imaging.htmCSEM's center for imaging•http://www.3dvsystems.com/technology/tech.html3DV Systems' repository of technical papers01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsOverview•Ladar stands for “Laser Detection and Ranging.”•Ladar is descriptive of all devices which use light waves to determine the distance of objects remotely.•The most common type of light used is laser light.LaserObjectLadar System01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsOverview•Ladar System emit a laser with some type of wave function.•The laser reflects off of the subject of the system and returns to the ladar system.•The ladar system measures phase offset of the returned ladar which is proportional to the distance the ladar traveled.LaserObjectLadar System01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsOverview•Flash Ladar Systems have an array of sensors in order to capture a scene of 3D points simultaneously. Generally, an optical lens is needed to focus the lasers from the object onto the array of sensors.Ladar SystemSensor ArrayLensObject01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsDesign Considerations•Unambiguous Range - Because the ladar system measures a phase offset, the system has some ambiguity as multiples of a phase offset of 2 π give the same distance. The unambiguous measurable distance varies with the frequency used in the ladar system.Possible ObjectLadar SystemPossible Object Possible Object01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsDesign Considerations•Accuracy – An important consideration for any ladar system is the accuracy of the ladar system. Various factors affect this important characteristic and will be discussed here.Ladar SystemAccuracy of Object Location01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsDesign Considerations: Accuracy•Modulation Frequency – increasing the modulation frequency improves the accuracy of the system, but decreases the unambiguous range.•Power of the laser – increasing the power of the laser improves the accuracy of the system, but the system will consume more power overall.•Ambient light – the less ambient light that is present in the scene, the better the accuracy of the system, however, this may not be a parameter that can be adjusted01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsDesign Considerations: Accuracy•Field of View – Decreasing the field of view improves the accuracy of the system, but some objects may require multiple shots and be stitched together.•Integration Time – Increasing the time the sensor integrates the results will improve the accuracy of the system, but the camera will take more time per shot to capture the data. Also, if the scene is not still, a long integration time can have motion blur.01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsApplications: Head Tracking•For security reasons, it is desirable to recognize a person from a database. Flash ladar has been used to characterize 3d features of heads in order to determine the person being captured. The advantage of ladar over visual camera is the ability to easily separate the head from the background.LaserLadar SystemHead Complex Background01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsApplications: Robotic Vision•In many robotic applications, obstical avoidance is a necessary quality. The ability to view the 3D world around the robot is a valuable asset. Flash ladar systems allow robots to capture 3D data quickly and the ability to process the data as a group, rather than individual points.Ladar SystemObstacleMobile Robot01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsApplications: Human-Machine Interaction•The ability to interpret human movements remotely is an area of interest to developers in variety of industrial fields. Its application could be used in computer peripheral devices as well as hazardous industrial environments. Flash ladar allows developers to quickly capture human data as a group rather than individual points giving a richer environment to work with.Ladar SystemHuman01/14/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsApplications: Automatic Target
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