r i t team members: dan lester → team lead chris feuerstein → lead engineer/electrical lead mike...
Post on 19-Dec-2015
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RIT
Team Members:Dan Lester → Team Lead
Chris Feuerstein → Lead Engineer/Electrical Lead
Mike Schwec → Electrical Support
Jacob Hillmon → Electrical Support
Huan Yu-Chen → Mechanical Lead
Delnessaw Hirpa → Mechanical Support
David Ng → Microcontroller Lead
Oliver Yuen → Microcontroller Support
P08201 – 10kg RoP08201 – 10kg Robbotic Platformotic Platform
This project is supported by a gift from the Gleason This project is supported by a gift from the Gleason Foundation to the mechanical engineering Foundation to the mechanical engineering
department at RIT.department at RIT. .
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Agenda
• Introduction – 10 minutes• Mechanical Subsystems – 20 min
– Platform Design – 10 minutes– Drive System Design – 10 minutes
• Electrical Subsystem – 20 minutes– Systems Overview – 3 minutes– Motor Controller (H-bridge) – 10 minutes– Battery Monitor – 7 minutes
• Microcontroller Subsystem – 15 minutes• Feedback/Q&A – 25 minutes
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Project DescriptionProject Description• The mission of this family of projects, within the Vehicle Systems
Technology Track, is to develop a land-based, scalable, modular open architecture, open source, fully instrumented remote/controlled vehicular platform for use in a variety of education, research & development, and outreach applications within and beyond the RIT KGCOE.
• This student team will re-design two modular, fully functional robotic platforms capable of carrying a payload anywhere in the robotics lab, room #9-2230 in Building #09 on the RIT campus.
• One drive platform shall be three wheeled, with at least one motor module, and a payload capacity of at least 2.5kg.
• The second drive platform shall have at least four wheels, with at least two motor modules, and a payload capacity of 10kg.
• Each platform will be required to accomplish two tests as stated in the PRP.
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Customer NeedsCustomer Needs
•The platform must re-use as many parts as last year’s designs as possible.
•The platform performs safely
• Must be able to carry a payload of 10kg
• Fits within $8000 Budget between all 3 project groups.
• The robotic platform must be battery powered
• The platform is robust
• Off the Shelf Components
• The platform performs testing requirements
• Impressive looking for high school students in the US FIRST robotics competition.
• Interchangeable modules (at least one) within 120 seconds
• Scalable with 100kg (with expectations to scale down to 1kg)
• Adaptable for other senior design projects
•Robot must be able to be controlled remotely
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P07204 Selected Concept
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Rectangular Configuration
Length: 26.75 inches
Width: 27.0 inches
Height: ~21.0 inches (without payload)
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Triangular Configuration
Length: 24.0 inches
Width: 23.0 inches
Height: ~19.0 inches (without Payload)
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• Made of inexpensive, strong, lightweight acrylic tubing• Easy assembly – members are joined with epoxy, and
screw
New Chassis Structure New Chassis Structure
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Modular Motor MountsModular Motor Mounts
• Easily mounts motor modules to chassis• Modules fixed in rails with two thumbscrews• Adding or removing modules is quick and easy• Made of inexpensive, easy to machine plastics
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Platform Selection Criteria
7204 8201
Platform Selection Criteria
Weight RatingWeighted
ScoreRatin
gWeighted
Score
Robust 20 3 0.6 4 0.8
Low Center of Gravity 10 3 0.3 4 0.4
Ease of Manufacture 20 3 0.6 2 0.4
Component Protection 15 3 0.45 4 0.6
Modularity 15 3 0.45 3 0.45
Weight 10 3 0.3 2 0.2
Durbality 10 3 0.3 3 0.3
Total Score 100 3 3.15
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New Motor Design Concept
• Focus on easy assembly, low center of gravity, shorten the overall height
Old New
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2:1 Motor Module
• Axle design has low ground clearance and large turning radius and restriction for infinite rotation
• Steering Motor torque restriction2:1 Axle 2:1 Belt
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1:1 Motor Module Design
• Flat design allows for infinite rotation • Low Design significant lower the center of gravity,
however it’s rotation is restricted by the wiring.
Flat Low
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Selection Criteria
Concepts (8201)
2:1 Drive Low Drive Flat Drive
Motor-Wheel Assembly Concept Selection
Criteria
Weight (%)
Ratingweighted Score
Ratingweighted
ScoreRatin
gweighted Score
Cost of Material 20 4 0.8 4 0.8 3 0.6
Weight 10 3 0.3 3 0.3 3 0.3
Appearance 30 2 0.6 3 0.9 4 1.2
Ease of Manufacturing 20 3 0.6 2 0.4 3 0.6
Adaptability 20 1 0.2 1 0.2 2 0.4
Total score 2.5 2.6 3.1
Rank 3 2 1
Continue? No No Yes
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Risk Analysis of Mechanical Components• Clear Acrylic Tubing
– Load Carrying Capability
– Bending of Members
– Impact Resistance
– Scratching / Weathering / Cracking
• Epoxy– Alignment of Members
– Cleanliness upon Application
– Fatigue over time
– Complete Failure under Loading / Operation
• Motor Mount Thumb Screw– Vibration under Operation
• High Density Polyethylene (HDPE) Motor Mounts – Flexing under loading
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Electrical Systems Overview
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Harris HIP4081A H-Bridge Driver IC and NMOS Bridge
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In House H-Bridge Logic Circuit
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In House CMOS H-Bridge
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Simulation of CMOS H-Bridge
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H-Bridge Design Comparison
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H-Bridge Selection Process
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Off-Shelf IC for Battery Monitor
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Custom Battery Monitor
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Simulation of Battery Monitor
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Microcontroller
Several Options:- Altera MAX EPM7128SLC84-7
- Freescale CSM12D
- Freescale MC56F8366MFVE (Sample)
- Atmel ATMEGA
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Atmel ATMEGA• • Microcontroller: ATMEGA128-16AU
• Speed: 16.000MHz• Processor Language: AVR
• Memory• Program Flash Memory (Internal): 128kBytes• RAM Memory (Internal): 4k Bytes• EEPROM Memory (Internal): 4k Bytes
• Input/Ouput• I/O Points Available: 48• I/O Points Connection: IDCC Connector
• A/D• A/D Channels: 8• A/D Accuracy: 10-bit
• Clocks• Real Time Clock: Yes (Internal)
• Timers• Timers: Yes - Two 16-bit Timers and Two 8-bit Timers• Capture/Compare: Yes - 1 Modules• PWM: Yes - 6 Channels
• Auxiliary Communication• RS232 Communication: Yes - 2 Channels
• Power Supply• Power-Supply: 7-12 Vdc
• Dimensions• LxWxH: 82mm x 62mm x 25mm (Including mounting supports)
• Cost• $28.90
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Freescale CSM12D
• Features: • MC9S12DT256 MCU, 80 LQFP• 256 KB Flash EEPROM• 4KB EEPROM• 12 KB RAM• 8-ch, 10-bit, ATD w/ external trigger• 8-bit Enhanced Capture Timer with IC, OC,and Pulse Accumulate capabilities• 7-ch, 8-bit PWM• RS-232 transceiver w/ DB9 connector• 4 MHz Clock Oscillator• On-board 5V regulator• 3 Push Button Switches: 2 User, RESET• 5 LED Indicators: 4 User, +5V• 60-pos pin-header providing access to MCUIO signals• DB9 connector
• Specifications: • Module Size 3.5. x 2.5.• Power Input: +9V typical, +6V to +20V
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Remote Control System
• Choices:– Wired (PC/Laptop)– Wireless (Laptop)– RC Kit– Infrared– RFID
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Laptop (Wireless)
Actor1
Laptop Microcontroller Motor Modules
Data Entry
Data passes through wire
Interpret & Process Frequencies
Output PWM Signals
Drives/Turn wheelsLaptop (Wireless Control)
Wireless Atena
Data sent through Wi-Fi or some other wireless connection (TCP/UDP)
– Pros: Wireless; Functionality; Durability;
– Cons: Complexity; Security; Cost
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Crossbow MICA2 Wireless mote
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Senior Design I – Next Steps
• Fall Quarter Week 8 – Detail Design Review
• Fall Quarter Week 10 – Final Presentation for SD1
• Spring Quarter Week 1 – Initial implementation of design concepts obtained from SD1
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Feedback/Q&A?