Systems Design Review P 17250 Robofish Charging Station
Systems Design Review P 17250 - Robofish Charging Station
Agenda 1. Team Vision 2. Functional Decomposition 3. Benchmarking 4. Morphological Chart 5. Concept Selection 6. Pugh Charts 7. Final Concept 8. Feasibility Analysis 9. Risk Assessment 10. Plans for next Phase JN
Team Vision for System Design Phase Plan to investigate the problem that was defined during Phase 1. Determine a systems-level design for the Robofish Charging Station (RCS) Establish functions and attributes necessary on the RCS. Perform function decomposition and compose morphological table. Develop concept selection criteria based on customer and engineering requirements. Analyze feasibility through calculations of various functions of selected concepts. Finalize concept using the Pugh Chart. JN
Functional Decomposition BM
Benchmarking To avoid duplicate efforts and save time, a variety of solutions and concepts are laid out to maximize efficiency. Products Link Energy Generation / Digital Power Storage Charge Current Input (to Communication Capacity charging device) Range Speed Cost Working Voltage m. A W Wh m USD V 5, 000 m. Ah http: //goo. gl/h Power Bank Ne. L 3 F Portable Battery Charger 2100 10. 5 25 N/A 50 5 Portable Solar http: //goo. gl/hv O 95 x Panel Array 750 13 N/A 170 17. 5 http: //goo. gl/U Roomba m 57 GI Charging Dock 1250 180 N/A ~2 60 16 2000 10 N/A 20 5 Samsung Qi Wireless Charging Mat http: //goo. gl/B CWnq. J LA
Benchmarking Products Link Charge Current Energy Generation / Input (to charging device) Speed m. A W Wh Digital Power Storage Communication Capacity Range Cost Working Voltage m USD V Grape Solar 200 -Watt Solar Kit Refer to citations ~ 1500 <= 600 200 N/A $295 3 ~ 12 Grape Solar 200 -Watt Solar Kit + 1 100 -Watt Panel Refer to citations ~ 1500 <= 900 300 N/A $405 3 ~ 12 Grape Solar 200 -Watt Solar Kit + 2 100 -Watt Panels Refer to citations ~ 1500 <= 1200 400 N/A $515 3 ~ 12 LA
Morphological Table Harvest Energy Store Energy Transfer Energy Attach Robofish Float on Water Communicate with Robo. Fish Ni. CD Solar Inductive Wireless Magnets Dock Floats Cable Direct connection Funnel Barrels Bluetooth Magnetodynamic wireless Robofish Grabs Feature on RCS Styrofoam Wi. Fi Multiple inductive charging points "Dock" that Robofish swims into Foam RF Lithium Wave Lead Acid Battery Ni. MH Wind JN
Concept Development - Float on Water Dock Floats (Best Option) No extra construction required, easy to use, reliable, durable, Can hold large loads (several hundred pounds) Foam Cheap, easy to implement Lots required to support the Lead Acid battery Wooden Platform Lots of extra work to design and build platform JM
Concept Development - Harvest Energy Solar (Best Option) Already have a large solar panel and charging system Easy to implement, relatively reliable, clean Doesn’t work at night, relatively slow Wind Requires more secure anchoring, very bulky Not practical Wave CP
Concept Development - Store Energy Lead Acid (Best Option) Heavy, inefficient, production is environmentally unfriendly We have a 200 Ah lead acid battery, very easy to charge, and relatively safe Lithium Ion Very dangerous, requires special charging circuitry, expensive Efficient, more stable voltage output through charge cycle Lithium Polymer As Li Ion, but more expensive GB
Morphological Chart - Communicate with Robofish Concept 1: Robofish sees LED and swims to the RCS Robofish attaches to rod below the water, using claw on front of Robofish then uses pump to rise the Robofish up the rod, and then guided into a connection at the top of the Robofish Concept 2: Robofish sees LED and swims to the RCS Robofish then swims up and into the bottom of the RCS Robofish is funnelled, and is then connected at the top of the Robofish CP
Morphological Chart - Attach to Robo. Fish Concept 3: Robofish sees LED and swims to RCS Robofish attaches to rod below the water Robofish then lowers into a Robofish holder that is motor driven with a lead screw Robofish holder is driven up and is connected at the top of the Robofish Concept 4: Robofish has connector on the front Robofish sees charging station (LED) and then swims into a dock on the station The connector is then channelled into the connection slot CP
Morphological Chart - Physical Connection Magnetodynamic charging Magnetic inductive charging Direct (wire) connection Multiple inductive charging pads External underwater generator shaft Overriding concern: Limitations with the Robofish GB
Pugh Charts Concept 1 vs Concept 2 Concept 1 Simpler Faster to Design Concept 2 Cheaper Lighter With the time limitation of Imagine RIT, it was BM
Final Concept Robofish Parking Sequence Robofish swims to rod w/ LED (using existing camera sensing capabilities) Robofish grabs rod with jaw on the front of the Robofish Pump in Robofish activates, causing the Robofish to elevate up Guides steer the Robofish into a docking port Interlocking connection (connector on top of Robofish), and charging of CP
Feasibility Analysis Energy Harvesting Question: How large would solar panels have to be to charge the 10, 000 mah 33. 3 volt batteries on the Robofish once each day on an average Rochester day? Assumptions ● ● ~40% losses due to conditions Average Rochester day Given ● ● ● C = 10, 000 [mah] Robofish Capacity V = 33. 3 [V] Robofish Voltage η = 15 [%] Solar Panel Efficiency H = 3. 76 [kwh/(m^2*day)] Solar Energy PR = 60 [%] Performance Ratio E=(C*V) E = 10, 000 mah * 33. 3 V *(1 Kah / 1 e 06 mah)*(1 charge/day) E = 0. 333 [kwh/day] ~~~~~~~~~~~~~ A = E / ( η * H * PR ) A = 0. 333 [kwh/day] / ( 0. 15 * 3. 76[kwh / (m^2*day)] * 0. 6 ) Solar Panel Area Needed = 0. 985 [m 2] A = E / ( η * H * PR ) JM
Feasibility Analysis Weight Question: How much will the RCS weigh? Why is this important? - Design of the shape and size. Buoyancy force calculations. Robofish Weight = --------------------RCS: Lead Acid Battery (X 2) = 15 kg (X 2) = Solar Panel (X 2) = 9 kg (X 2) = Controls = Misc = --------------------RCS Total = --------------------RCS and Robofish Total Weight = 20 kg. 30 kg 18 kg 3 kg 4 kg 55 kg 75 kg CP
Feasibility Analysis Energy Storage Question: Can we use off the shelf solutions to meet our customer and engineering requirements regarding charging speed at a reasonable price. Calculations Assumptions ● ● TI offers Li ion charge controller which charges up to 4 Liion cells in series. Another IC from LT offers charging of up to 9 cells in series. The Robofish contains 3, 9 cell strings of batteries and can be multiplexed on the charger. Requires to charge the battery system within 12 hours. ● ● ● With 4, 9 cell strings, if the 9 cell charger was used, the 1 IC with a 3 to 1 multiplexing setup can then be used. Requires charging string every 12/3=4 hours. Approximate t = (capacity / current) 4 h = 10 Ah / X Amps 2. 5 amps charging current. The LT IC can output up to 8 amps - it is ABLE to be used. The TI IC requires (36 / 4) = 9 chargers, or 3 chargers, multiplexed 3 ways. - Expensive, complex and unsafe. NOT ABLE to be used. GB
Feasibility Analysis Energy Transfer Question: How fast can the RCS transfer energy Iva induction vs direct connection? Assumptions ● ● ● ● Robo. Fish has 20 Ah at 33. 3 V. Solar Panel collects up to 39 Watts. 50 Watt solar panel at 13 V with 3. 0 A 1 Lead acid battery has 125 Ah with 20 -A for 6 hours [12 V]. 1 Lithium ion battery has 21 Ah with 20 -A for 1 hour [12 V]. Discharge is proportional to charge. Robofish stores 666 Wh (20 Ah). Best Options: DC - 2. 8 hrs Energous - 5 ft 121 hrs Qi - 120 W 5. 5 hrs Research Energous Co. Tech: ● ● ● Up to 15 ft with 1 W (666 hrs) Up to 10 ft with 3. 5 W (190 hrs) Up to 5 ft with 5. 5 W (121 hrs) Inductive Charging: ● ● 5 mm - 40 mm 5 W, 120 W, 1 k. W Direct Connection (240 W, 2. 8 hrs) ● ● Lead acid: 1. 5 k. Wh Lithium ion: 0. 25 k. Wh Qi Standard: ● ● ● 5 W for 133 hr 120 W for 5. 5 hr 1 k. W for 0. 6 hr BM
Feasibility Analysis - Planned Attachment Mechanism Robofish detection Range: Test how far away the Robofish can detect colored objects and colored lights Guide mechanism: Fabricate prototype guides to ensure the Robofish docks reliably Connection force: Measure upward buoyancy force of Robofish to determine how much force it can apply to mate with the RCS *We attempted to operate the Robofish in the pool but it leaked JM
Risk Assessment LA
Major Risks Risk L*S Status Current Robofish battery is a safety risk for our testing and leaves no room in the Robofish for a battery management system 9 ● Customer approved new Robofish battery ● Currently looking for a smaller, safer battery with an integrated BMS Robofish leaks; inhibits our ability to perform testing 6 ● Robofish leaked when we attempted to test it ● Currently finding and obtaining sealant Robofish object detection range is not far enough to locate the RCS 6 ● Range test attempted, failed due to leak ● Will test when Robofish leak is fixed Not enough energy can be harvested to power the Robofish in a reasonable time frame 4 ● Feasibility analysis shows 1 m^2 of solar panel is sufficient ● Current solar panel is. 67 m^2, a second panel is being considered LA
Current Battery Setup
Plans for Next Phase - Preliminary Detailed Design (PDD) ● The goal of the PDD phase is to turn design concepts into a ‘draft’ full system design ● This phase will require the creation of system drawings, models, and flowcharts as well as a full preliminary Bill of Materials ● Additionally, test plans will be drafted to verify customer requirements are met JM
Citations ● ● Solar Energy H = 3. 76 [kwh/(m^2*day)] http: //www. Solar. Energy. Local. com Grape Solar 200 -Watt Solar Kit - http: //www. homedepot. com/p/Grape-Solar-200 -Watt-Off-Grid-Solar-Panel-Kit-GS-200 KIT/203505912 Grape Solar 200 -Watt Solar Kit + 1 100 -Watt Panel - http: //www. homedepot. com/p/Grape-Solar-300 -Watt-Off-Grid-Solar. Panel-Kit-GS-300 -KIT/203505917 Grape Solar 200 -Watt Solar Kit + 2 100 -Watt Panel - http: //www. homedepot. com/p/Grape-Solar-400 -Watt-Off-Grid-Solar. Panel-Kit-GS-400 -KIT/203505963
Questions?
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