r i t team members: dan lester → team lead chris feuerstein → lead engineer/electrical lead mike...

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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?