P16221 – FSAE Shock Dynamometer System Level Design Review September 29, 2015

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

Background (5 min) System Analysis (10 min) Concept and Architecture Development (5 min) System Level Proposal (10 min) Engineering Analysis (15 min) Risk Assessment (5 min) Test Plan(how we will meet the specs) (5 min) Updated Project Plan (5 min) Question and Answer (15 min) Agenda

A shock dynamometer is a measurement device supply an input displacement vs time profile measure the response (both displacement and force) of a damper. Overall: a tool used by engineers to tune the suspension and ride quality of a vehicle in any application Background: What is a Shock Dynamometer?

The goal of this project – Design a device to characterize dampers – Capable of supplying a displacement input profile in time and measuring force, displacement, and temperature responses of a damper – Existing machines will be analyzed for compatibility. If there are no existing machines that will support the damper dyno integration, a new machine will be developed Background: Problem Statement

1.Cost less than $3,000 2.Able to be moved in the shop easily 3.Reproduce damper displacements from track data 4.Measure damper forces 5.Measure damper shaft position 6.Measure damper temperature during test 7.Save and recall test data for post processing 8.Maximum footprint of 4’ x 4’ 9.Accommodate wide range of damper sizes Background: Customer Requirements

Background: Engineering Requirements

Predicted Costs

House of Quality Overall Picture

House of Quality 1. Customer Reqs

House of Quality 2. Functional Reqs

House of Quality 3. Inter-relationships

House of Quality 4. Roof

House of Quality 5. Targets

Functional Decomposition Damper Characterization Accessing Damper/Prep TestRunning Test Data Collection User Safety/Results Output

Functional Decomposition Accessing Damper/Test Prep

Functional Decomposition Running Test

Functional Decomposition Data Collection

Functional Decomposition User Safety/Result Output

System Level Design Concept Data Test Commands Post Processed Results

System Level Design Flowchart

Morph Chart

Morph Chart Cont.

Ball Screw Actuation Capable of track data input profile – >10 in/s shaft speed – >1500 lbf input force System Level Proposal

Cam/Rotary type motor sizing Memory Requirements Microprocessor Read Speed Testing Serial Speed Analysis Load Cell Analysis Engineering Analysis

Determine a power requirement – Inputs 10 in/s shaft speed 1500 lbf load capability – Output 2.72 Hp – Conclusion Need a 3-5 Hp motor Cam/Rotary motor

Calculate memory requirements for data acquisition – Inputs Track data sampled at 500 Hz (0.002 seconds between samples) Data consists of a pair of numbers (time, displacement) – Outputs 1,800,001 samples MB requirement – Conclusion Eliminate time and send measurements at a constant Record 1-5 minutes of data and send to PC in chunks Memory

Read Speed Test – Simulated series of analog input reads – ATmega328P-XMINI – Results Mean us Min 332 us Max 432 us – Conclusion Should have plenty of time to control actuator at 125Hzcontrol speed 5 variables in sketch took 16% of available stack space Microprocessor

Serial Speed Analysis – Inputs Memory Requirements (64 bits of data in 0.002s) – Output 32,000 bits/s – Conclusion- feasible baud rates: RS-232

Source a load cell that meets required specifications – Inputs Hz No measurement phase lag (+) and (-) force measurement capabilities < $1000 – Output PCB A/084A100 – Conclusion Exceeds all physical requirements Need a discount or sponsor (> $1000) Load Cell

Risk Assessment

Emergency circuit breakers – Open enclosure door, verify the system stopped – Press emergency switch, verify the system stopped Sensor measurements – Force (give a known weight – get the reading) – Temperature (measure room temperature) – Position (command to move to a known distance – measure) – Verify the measurements are within acceptable range Test Plan

Data collection speed (~250 Hz – 4ms period) – Collect data from the sensors and time taken Track frequency (~125 Hz – 8ms period) – Command the controller to move a period within 8 ms – Verify the frequency from sensor data Variable stroke range – Command the controller to vary the stroke range – Verify with the reading from linear potentiometer Data format – Verify.csv format in file system Test Plan

Replay track data – Use the data from.csv and produce graphs Sturdy base and mounting to withstand vibrations – Apply 100 lbs to top, measure deflection (<0.005in) Eye-to-eye distance/ overall footprint – Tape measurements Mobility – Customer judgement: 1 (zero mobility) – 10 (excellent mobility) Test Plan

Updated Project Plan

Questions?