P16221 – FSAE Shock Dynamometer Detailed Design Review December 8, 2015

Aung Toe – EE Jim Holmes – EE – Project Manager Sal Fava – ME – Chief Engineer Chris Batorski – ME – Facilitator Andrew Dodd – ISE P16221 – MSD Team

Address concerns from PDDR Safety Considerations and Test plans Engineering Spec Updates Current Bill of Materials Model Overview Mechanical Systems Analysis Electrical Schematics Risk Management Project Plan Agenda

What is the timing on getting money? – $1250 total between Baja and Hotwheelz Is the table cheaper to make than buy? – Purchased table will not meet our requirements How did you come to 350lb marginal, 500 lb ideal weight? – 350lbs are FSAE shock specifications, 500lbs is example of sport automotive damper What is the factor of safety in isolator sizing? – 1.5 as defined by ratio of natural frequency of rig to natural frequency of isolator Questions from PDDR

Hire electrician for 208V – Motor circuit is finished, working with ME shop Test plans using function generator for data transfer – Will generate random data from micro to pc to test transfer rates Develop an Engineering Analysis vs. Risk vs. Verification Test metric to make sure everything is covered. – Updated continuously (discussed later in presentation) Issues from PDDR

Do you need to monitor motor temperature? – Generates more heat under load Thermocouple for validation testing Temp sticker during normal operation Will have an electric fan instead of mechanical to deal with heat What do you most worry about the project? – Items highlighted on risk assessment Expectations for this review (addressed throughout) – Test plans Testing implies some level of confidence How you are going to stress the system beyond design intent Start thinking how and what data to test Questions from PDDR

System Level Design Flowchart

Mechanical Test (MT) – MT1: Planned to occur after base manufacturing and assembly is complete – MT2: Planned to occur once full test stand is assembled Electrical Test (ET) – ET1: Safety circuit test to occur before any full system testing begins – ET2: Sensor testing scheduled for after system is assembled (initial bench tests are also included) Program Test (PT) – PT1: Program communications and data saving test Test Plans Full System Tests

Test Plans Corresponding Eng. Rqmts.

Goals of sub-system: – Protect user from serious damper failure – Not impede user activities within working zone – Low cost Important features – Enclosure – Emergency Stop Switch – Door Interlock – Safety Circuit Subsystem Design Safety

Major Components Aluminum Extrusion Frame – Minitec 45x45 F Plastic Shielding – Polycarbonate sheeting Door Safety Latch Safety Circuit – test plan test plan Interfaces Test stand base – Bolted to base Work Area – Surrounds the masts and test area Emergency Stop Switch – Will be mounted to the frame Safety Sub-System Overview

Overall Dimensions – Height: 48 in – Depth: 12 in – Width: 36 in Bolted to table – 8X 5/16-18 Bolts Held together with custom designed brackets – An effort to reduce cost of the system Safety System Enclosure Design

Overall Dimensions – Height: 46 in – Depth: 12 in – Width: 32 in Currently Designed with Standard MiniTec hinges and handles – Could replace with custom parts Safety System Door Design

Top Plate – Used to hold top of enclosure to the uprights – Thickness: ¼ in – Material: Aluminum Bottom Plate – Bolts the enclosure assembly to the test stand – Thickness: 7/16 in – Material: Aluminum Safety System Custom Plates

Used to lock the enclosure when test is being run IDEM 16.5mm Mount – Safety Switch: $29.50 – Actuator Key: $11.50 Available from Automation Direct Safety System Door Interlock

MiniTec 45x45 Extrusion Lengths – 49” QTY: 4Part: Uprights – ” QTY: 2Part: Front and Rear Cross – 8.456”QTY: 2Part: Left and Right Cross – ”QTY: 2Part: Door Top and Bottom – QTY: 2Part: Door Left and Right – Minimum Total Length: 35’ 9” Polycarbonate Sheeting 5/16” thick – 47.83” x 33.66”QTY: 1Part: Back Shield – 47.83” x 9.66”QTY: 2Part: Left and Right Shields – 33.66” x 9.66”QTY: 1Part: Top Shield – 44.63” x 29.72”QTY: 1Part: Door Shield – Minimum Total Area: 4185 in 2 ( less than 5’ x 6’ sheet ) Safety System Manufacturing Cut List

Engineering Requirements

BOM

Overall System Geometry From SSLDR From PDDR DDR

DDR Geometry

350lb marginal, 500lb ideal vertical force through the actuator, damper and into the crossbar FOS of 2 used in all calculations Design for stress levels under the endurance limit, infinite fatigue life Welded structure Knockdowns – Aluminum weld-area strength= 0.5 base material – Steel weld-area strength= 0.8 base material Ideally every component in a system would have Margin=0 – Positive = over-designed – Negative = under designed Review of Load Cases/Constraints

Analysis: Isolator Sizing Efficiency: Isolator Sizing – Initially took 1 evening, could repeat in 1 hour.

Beam deflection Applied LoadP[lb]500 factor of safetyXs[-]2 LengthL[in]36 ModulusE[lb/in2]2.9000E+07 baseb[in]2 heighth[in]4 wall thicknesst[in] Moment of inertiaI[in4]2.2966E+00 motor mount deflectiondelta[in]7.2970E-03 side bar deflectiondelta[in]7.2970E-03 Total base deflectiondelta[in]

Analysis: Clamp Load

Actuation Assy

NICE ball bearings – RBC 3030 Meet dynamic load rating with FOS>2 on ideal spec Sealed Bearing Selection

Check for Buckling

High Impulse load of 1730lbf including force from motor Possibly use a shear keyway to protect motor Impulse

Actuator rail binding test – No product specs on side load Isolator sizing test – Weigh the completed system for the foot isolators – Weigh all electronics for mount sizing System deflection test – Use dial indicators Electric motor fan sizing – Measure CFM output Anemometer Mechanical Test Plans

Finish prints Complete hardware order Complete stock order Touch up model Look into shear keyway vs electrical failsafe Mechanical to do for Gate Review

Monitor Safety Circuit Loop Collect Sensor Data – Temperature – Force – Position – Time Send/Receive data via UART Motor Control System Software Features

Arduino Dataflow

TI ISO124 Analog Isolator

VISHAY CNY17 Digital Isolator

Electrical System Schematic

Electrical Wiring Schematic

Serial Interface Test

IR sensor test Proof of Concept: Testing so far

Analog Isolation Digital Isolation Motor Drive Load Cell – Resolution Tests Planned

Goals of Subsystem – Provide user with a way to control and program the test stand – Post processes the raw data and saves it in.csv format Important Features – Car Parameter Inputs – Post Processing – Live Graph Display Subsystem Design Software Interface

Software Interface (SI Units)

Software Interface (US Standard Units)

EquationsVariables K w = Wheel Rate K s = Spring Rate MR = Motion Ratio ω s/us = Natural Frequency (sprung/unsprung mass) m s/us = Mass (sprung/unsprung) c crs/us = Critical Damping (sprung/unsprung mass) Software Interface Calculations

Power Management

Serial Interface Test

Serial Interface Test (Automated)

Risk Assessment

Updated Project Plan

Questions?