A Critique of Hume's Understanding of Induction in Light of Thomistic Thought

Annotated Bibliography

Thomas Aquinas, Summa Theologiae, I, q. 2, a. 1-3, at New Advent, www.newadvent.org.  St. Thomas addresses the question of God's existence and how we come to knowledge of it.  This is pertinent to our research because it provides an example of how Aquinas uses induction to provide proof of God's existence.

Kenneth T. Gallagher, The Philosophy of Knowledge (New York: Fordham University Press, 1962), 208-213.  Gallagher discusses and critiques Hume's contributions to epistemology and his critique in particular of the use of inductive arguments.  This is relevant to our research because it provides an overview of the two perspectives on induction.

David Hume, An Inquiry Concerning Human Understanding (Cambridge: Hackett Classics, 1993).  A treatise that presents Hume's skepticism about the scope of human understanding.  This is relevant to our research because it specifically addresses his views on causality and inductive reasoning.

Alexander R. Pruss, The Principle of Sufficient Reason: A Reassessment (Cambridge: Cambridge University Press, 2006).  An explanation and history of the development of the principle of sufficient reason and whether it should be considered among the first principles.  This is relevant to our research because provides an opposing view to Hume's understanding of the principle of causality.

Sense and Avoid Sensor Selection for Small UAV

Detect, sense and avoid (DSA) systems are responsible for detecting conflicting traffic, determining the right of way, analyzing flight paths, maneuvering to avoid collision, and communicating with other aircraft in the air.  The requirements for DSA for commercial Unmanned Aerial Vehicles (UAVs) are currently still in work by the Federal Aviation Administration (FAA) however an outline of what it will most likely look like is available.  UAVs under 55lbs that are flown for recreation or hobby purposes currently have no requirements for sense and avoid other than they must be flown within line-of-sight away from populated areas, however the requirements for commercial UAV usage flying beyond-line-of-sight (BLOS) will be much more rigorous (Berry, 2009). 

For detecting conflicting traffic, the UAV system will need to continuously be scanning for threats, minimize false alarms and misses, provide an operator threat data, cover a field of view of 110 degrees horizontal and +/- 15 degrees azimuth, track all targets within a minimum range, and determine closure rates (Berry, 2009).  The system will need to be able to detect and identify potential collisions at a far enough range that a minimum of 500ft separation between vehicles can be maintained (Berry, 2009).  It will do so by making use of the sensors on-board to calculate flight paths and determine the time available before needing to maneuver to avoid a potential collision (Berry, 2009).  For a small UAV of less than 55lbs the microPOP electro-optical stabilized payload is a great option for helping achieve this.

The microPOP is a great option because it allows for both day and night usage making use of a color zoom camera with near infrared (IR) capabilities for daytime operations and an uncooled forward looking infrared (FLIR) camera for night operations (MicroPOP, 2015).  The day and night payloads can be interchanged quickly and depending on configuration have a system weight of between 2.2 and 3 lbs (MicroPOP, 2015).  At a cost of over $100,000 for each unit it is not a cheap option by any stretch but the capabilities it offers far surpass just strapping a HD camera onto your aircraft (MicroPOP, 2015).  Available options to add on in addition to the camera include a laser range finder, laser pointer, automatic video tracker, HDTV, and INS/GPS (MicroPOP, 2015).  The sensor is compact at only 4” in diameter and 7” tall, while requiring a 23 Watts of power in order to run (MicroPOP, 2015).  The field of view is 170 degrees horizontal and -90 degrees, + 20 degrees azimuth with a slewing rate of 100 degrees/sec on the gimbal (MicroPOP, 2015).  The day camera also features 10x continuous zoom.  The microPOP sensor is currently being used successfully on UAV’s such as the Panther Fixed Wing VTOL UAS and the BirdEye 400 UAV.  For small unmanned systems on short-range observation missions it is an excellent option for providing enhanced imaging capabilities to assist in a sense and avoid system.

References

Berry, M., Hansen, K.R., Hottman, S. B. (2009). Literature Review on Detect, Sense, and Avoid Technology for Unmanned Aircraft Systems

(DOT/FAA/AR-08/41). Las Cruces: FAA.

MicroPOP Electro-Optical Stabilized Payload. (2015). Retrieved from http://www.iai.co.il/2013/18688-34442-en/SystemMissileandSpace_Tamam_Electro-Optical.aspx

Hermes Universal Ground Control Station

The Silver Marlin Unmanned Surface Vessel (USV), designed and built by Elbit Systems, makes use of the Hermes Universal Ground Control Station (UGCS) (Hermes Universal, 2015). The Hermes UGCS can be a fixed standard design or a more compact mobile design and features side by side pilot operation for redundancy (Hermes Universal, 2015).  However the system is designed to be able to be operated by a single operator.  The Hermes UGCS is made up commercial-off-the-shelf hardware and software tools which allow for full control of the Silver Marlin USV including full mission debriefing, in-flight mission editing, and payload control (Hermes Universal, 2015).  The UGCS is made up of a ground data terminal (GDT), a remote video terminal, and a flight line tester/loader for Unmanned Aerial Vehicle (UAV) control (Hermes Universal, 2015). The system is capable of controlling two vehicles simultaneously with a single UGCS and two GDTs (Hermes 450, 2015).

The Hermes UGCS fixed station layout features multiple LCD displays, a control stick on the RH side of the operator for controlling the vehicle and video feed and a control stick on the LH side of the operator for interacting with the main display such as setting way points.  The displays are setup for each of the operator stations with two stacked on top of each other, a small tablet off to the side of each operator, and a single display between the two operators.  The two stacked displays act as the main displays the operator uses while flying the aircraft and controlling the payloads, the bottom one showing the video feed coming from the camera on-board the vehicle and the upper one usually showing a zoomed in map of the area the vehicle is in.  The center display between the operators is used to display a map with a broader view of the area being operated in for increased situational awareness.  The touchscreen tablet is used for keeping track of mission objectives, relaying intelligence to the operators, and monitoring the status of systems on-board the vehicle.  Figure 1 below shows the Hermes UGCS with operators in both stations.
 

 

Figure 1: Hermes Ground Control Station with Two Operators (Hermes 450, 2015).

One issue with the Hermes UGCS is that the current displays do not provide a very wide field of view for the operators.  This reduces situational awareness and can result in disorientation when the operator is under high workloads.  This is critical especially when trying to navigate a crowed port as in the case of a USV or on landing and takeoff for a UAV.  I would recommend having larger, wider displays and cameras on-board vehicles that provide at least 180 degrees field of view.  The operator should then also be able to choose between a variety of different field of views while flying depending on the environment and circumstances they are in. 

References:

Hermes 450 Multi-Role High Performance Tactical UAS, Israel. (2015). Retrieved from http://www.airforce-technology.com/projects/hermes-multirole-high-performance-tactical-uas/

Hermes Universal Ground Control Station (UGCS). (2015). Retrieved from https://www.elbitsystems.com/elbitmain/area-in2.asp?parent=3&num=36&num2=36

Voyager 1 Spacecraft Data Management

The Voyager 1 spacecraft began its mission in 1977, setting out to reach the edge of our solar system and beyond (Mission, 2015).  It met its goal and continues on into deep space with its mission planned to continue on around 2020 when its thermoelectric nuclear generator will no longer create enough power to sustain the mission (Operation, 2015).  The thermoelectric nuclear generator in Voyager 1 had a power output of around 420W when first launched and makes use of an 8-track digital tape recorder for storing data gained from science instruments (Voyager, 2012).  The data storage strategy for Voyager 1 is to mainly transmit data real time so as to avoid the need to store data on the spacecraft, however some data from the Plasma Wave Investigation sensors are stored long term on the spacecraft (Mission, 2015).  The tape recorder has the ability to store 63.5 MB of data which is enough to store about 100 images or a few graphs worth of data at a time (Voyager, 2012).  Science data is returned to Earth real time at 160 bps, and the Deep Space Network (DSN) 34 meter antennas are used to capture around 16 hours of data a day (Mission, 2015).  Once a week the spacecraft also records 48 seconds of high rate Plasma Wave Investigation (PWS) data onto the digital tape recorder and every 6 months that data is sent back to Earth (Mission, 2015).  The 70 meter antennas of the DSN have to be used to support that data capture (Mission, 2015).  Voyager 1 has 10 science sensor systems on board that gather data in order to perform its mission of exploring our solar system and beyond (Operation, 2015).  These 10 systems are detailed below: 

• Ultraviolet Spectrometer (UVS), 2.4 W – measures atmospheric properties of planets and UV radiation emitted from them (Operation, 2015).

• Photopolarimeter System (PPS), 1.2 W – telescope that measures the amount of light scattered or reflected by planets (Operation, 2015). 

•  Infrared Interferometer Spectrometer (IRIS), 6.6 W – measure infrared radiation emitted or reflected by planets (Operation, 2015).

•  Low-Energy Charged Particle Detector (LECP), 4.7 W – measures low-energy charged particles (Operation, 2015).

•  Triaxial Fluxgate Magnetometer (MAG), 2.2 W – investigates patterns of planetary magnetic fields (Operation, 2015).

•  Planetary Radio Astronomy (PRA) and Plasma Wave Subsystem (PWS), 6.6 W – used to sample plasma behavior in and around planets (Operation, 2015).

•  Cosmic Ray Subsystem (CRS), 6.5 W – records the number and energy of high-energy cosmic ray particles (Operation, 2015).

•  Plasma Spectrometer (PLS), 4.2 W – measures the lowest-energy particles (Operation, 2015).

•  Imaging Science Subsystem (ISS), 14 W – two cameras with attached telescopes to take    pictures (Operation, 2015).

Unfortunately the thermoelectric nuclear generator decays overtime and produces approximately 4.2 watts of power less each year (Operation, 2015).  This decline has made it necessary to end operation of 5 of these science instruments and their supporting systems so far and the other 5 instruments will have to be turned off one by one as well leading up to 2020 when there is no longer enough power to support gyro operations which allow the spacecraft to make sure it’s antenna points towards Earth to insure data is transmitted successfully (Operation, 2015).  Consider Voyager 1 was built in 1977, it’s a marvel what it’s been able to accomplish however considering a modern phone has many times its data storage capacity today it’s hard not to wish it didn’t have a much greater amount of data storage onboard so that it didn’t rely on having constant communication with Earth in order to transmit science data.

References

The Mission. (2015). Retrieved from http://voyager.jpl.nasa.gov/spacecraft/

Operation Plan to the End of the Mission. (2015, May 18). Retrieved from http://voyager.jpl.nasa.gov/science/thirty.html

Voyager 1 is leaving the solar system, but the journey continues. (2012, December 13). Retrieved from http://theconversation.com/voyager-1-is-leaving-the-solar-system-but-the-journey-continues-11184

Aerial Photography UAS and FPV Racer UAS

      First Person View (FPV) racing seems to the be the latest craze among RC enthusiasts and a great example of one that just recently became available to buy off the shelf is the Team Black Sheep (TBS) Gemini FPV Racer.  Based on the design by an award-winning multi-rotor pilot Dr. William Thielicke, the Gemini is capable of reaching speeds up to 50 mph and thanks to its forward tilting rotor design can do so without having the forward camera point towards the ground making it hard to see where you're going (TBS, 2015).  The 10 degree forward tilt of the motors decreases the angle of attack of the body of the hexacopter in forward flight, which coupled with the aerodynamic design of the body reduces drag (TBS, 2015).  This design also allows for the Gemini to remain very agile, which is equally important to speed in most race scenarios (TBS, 2015).  The option to have a built in FPV camera that is HD insures clear video, and the aerodynamic design of the body that doubles as great protection in case of a crash, are great benefits (TBS, 2015).  The Gemini uses TBS 4A Bulletproof Electronic Speed Controllers (ESC) with built-in universal battery elimination circuits (UBEC) which prevents the need to worry about interference from the electric motors affecting the FPV camera since everything is run off of one battery (TBS, 2015).  Managing radio-frequency interference (RFI) by paying attention to the positioning of the battery, camera, and transmitter with relation to each other is an important part of making sure to get the most out of a FPV system (Mikowski, 2013).

(FPV, 2015)

     Another growing use for RC aircraft is aerial photography and video, and a great example of an aircraft that is currently available to meet this need is the Multirotor G4 Skycrane by Service-Drone.  Its octo-rotor configuration, with a 3-axis brush-less gimbal system, allows a user to mount a RED dragon 6K or RED epic 5k camera below the aircraft with unhindered, 360 degree sight lines (Multirotor, 2015).  The aircraft provides an incredibly stable platform from which to take pictures or video thanks to the 360 degree gyro-stabilized camera mount and a flight control system that corrects flight position 512 times per second while holding a fixed position (Multirotor, 2015).  It can also maintain that high stability in winds up to 33 mph, which means you won't be limited to filming only when there are low winds (Multirotor, 2015).  The Skycrane also features some auto-pilot capabilities such as position hold, coming home, automatic landing, way point navigation, and automatic altitude control that can be very useful for inexperienced pilots trying to use the system (Corrigan, 2014).  The G4 Skycrane gives the user the ability to mount a professional 4K camera on a stable platform that is capable of meeting the needs of almost every kind of film production (Film, 2015).

References

Corrigan, F. (2014, November 6). Top Business Drones For Aerial Imagery And Cinematography. Retrieved from http://www.dronezon.com/drone-reviews/top-business-drones-for-aerial-view-imagery-photography-cinematography/

Film TV. (2015). Retrieved from http://www.service-drone.com/en/production/film

FPV RACER. (2015). Retrieved from http://team-blacksheep.com/products/prod:gemini 

Multirotor G4 Skycrane. (2015). Retrieved from http://www.service-drone.com/en/shop/uav/multirotor-g4-skycrane/multirotor-g4-skycrane-v

Mikowski, E. (2013, October 16). FPV Setup Wiring - Reducing RFI Interference. Retrieved from http://www.fpvforme.com/fpv-setup-wiring/

TBS GEMINI Mini FPV Hex. (2015, February 16). Retrieved from http://www.team-blacksheep.com/tbs-gemini-manual.pdf

Unmanned Systems in Maritime Search and Rescue Operations

     The autonomous underwater vehicle (AUV) called Bluefin-21 and developed by Bluefin Robotics was recently deployed in the South Indian Ocean in April 2014 by the U.S. Navy to assist in the search for the missing Malaysian Airlines Flight 370. (Bluefin, 2015)  The Bluefin-21 assisted in the search by making use of its EdgeTech 2200-M side scan sonar sensor and a high resolution digital camera with LED strobe built in. (Kozak, 2012) The EdgeTech 2200 side scan sonar operates at both 100 and 400 kilohertz to detect anomalies using the 100 kilohertz, 500 meter range frequency to acquire targets and then switching to the 400 kilohertz, 75 meter range frequency to classify those targets. (Kozak, 2012)  The camera could then be used to photograph targets the EdgeTech2200 had identified as of interest.  The images were then stored on a flash drive which was retrieved after the vehicles mission was complete and reviewed later to determine if it had found the aircraft.  Hopefully in the future there will also be the option to take video and the data storage space will be increased.

     The Bluefin-21’s use of the EdgeTech 2200-M side scan sonar and an ultra-short baseline (USBL) acoustic positioning system are exteroceptive and proprioceptive sensors respectively that are well suited for the underwater environment they operate in.  The USBL acoustic positioning system is used to add further accuracy to the GPS/INS data and is used in circumstances where the deep water, long range tracking of underwater targets is needed. (USBL, 2015)  It works by calculating the position of a subsea target by measuring the range and bearing from a vessel mounted transceiver to an acoustic transponder fitted to the target. 

     The Bluefin-21 in the case of searching for Malaysian Airlines Flight 370 is a great example of how an unmanned system has an advantage over a manned one.  The great toll repetitively searching for long months would have on a manned submarine crew is avoided and the search can also be conducted at a much lower cost than if a manned vehicle was used.  The Bluefin-21 also does not need to have a pressurized hull which reduces the cost of producing the vehicle greatly.  The future use of AUVs in search and rescue missions looks bright with future development ideas like the Hydra program on the horizon.  The Hydra program is a DARPA project that seeks to demonstrate an unmanned undersea system with the capability of launching UAVs and other UUVs into environments quickly around the world. (Keller, 2013)

References

Bluefin-21 Autonomous Underwater Vehicle (AUV), United States of America. (2015). Retrieved June 13, 2015, from http://www.naval-technology.com/projects/bluefin-21-autonomous-underwater-vehicle-auv/

Keller, J. (2013). DARPA considers unmanned submersible mothership designed to deploy UAVs and UUVs. Retrieved June 13, 2015, from http://www.militaryaerospace.com/articles/2013/07/darpa-uuv-mothership.html

Kozak, G. (2012). Use of AUV for Deepwater Shipwreck Search. Retrieved June 13, 2015, from http://www.bluefinrobotics.com/assets/Papers/Use-of-AUV-for-Deepwater-Shipwreck-Search-Sea-Technology-Sept2012.pdf

USBL - All Systems. (2015). Retrieved June 13, 2015, from http://www.sonardyne.com/products/positioning/usbl-all-systems.html

Future Applications of PZT Sensors in UAV Applications

     Aircraft health monitoring systems especially on unmanned systems are something that is coming around the corner in UAV development especially of larger, more expensive systems.  Having the ability to diagnose the structure of an aircraft real-time while in flight and make adjustments as required as well alert when maintenance needs to be done on certain areas before greater structural damage occurs would help add to the lifespan, survivability, and lower maintenance costs of future UAVs.  Piezoelectric (PZT) sensors may be one of the technologies that helps achieve this.
     Piezoelectric sensors work by using the piezoelectric effect to measure changes in pressure, acceleration, temperature, strain, or force and converting them into electrical charge.  These sensors take advantage of the ability of certain materials to accumulate electric charge in response to applied mechanical stress.  Piezoelectric sensors have the potential to be incorporated into future health monitoring systems on UAV's in a variety of ways but being used to monitor the structural integrity of an aircraft and assist in damage assessment is one way that has shown promise.  Experiments have shown that PZT sensors applied at critical locations on the aluminum or composite structure of an aircraft could measure the intensity of the load from accelerations of the aircraft as well as assist in damage assessment by comparing the difference in interpreted engineering parameters of damaged structure with healthy structure. (Sathyanarayana, 2013)  The potential to incorporate piezoelectric materials into composites shows promise for the potential of a light weight design that can be incorporated into an aircraft's structure with ease.
     One thing that would need to be developed to gain the full benefits from piezoelectric sensors however is a health monitoring algorithm to properly diagnose the information coming from the PZT sensors. (Sathyanarayana, 2013)  This is vital to proving how useful PZT sensors could be and whether they are able to just assess whether damage has been done or not, or whether they can also assess the intensity of the damage, specific location, and loading intensity. (Sathyanarayana, 2013)
 
 Reference:
Sathyanarayana, C., Raja, S., & Ragavendra, H. (2013). Procedure to Use PZT Sensors in Vibration and Load Measurements. Retrieved June 6, 2015, from http://www.hindawi.com/journals/smr/2013/173605/