P15280: Hot Wheelz Test Bench

Problem Definition

Table of Contents

You may want to consider using the Problem Definition Documents directory to store this information. Some templates are available there for your use.

Project Summary

The RIT Hot Wheelz Electrical Vehicle team is taking on a large challenge and building their first ever Formula SAE Electric vehicle. There is currently no method to test the electro-mechanical drive system. Due to the scope of the project, the team is in need of a user friendly, size appropriate testing platform. Key electrical drive system performance data, such as torque output and battery life, are required to optimize the system capabilities. Safe operation of the electrical components, smooth integration of the completed drive system onto the chassis of the vehicle, and the ability to verify the system's compliance to the SAE rules are desired. The project will be constrained by a limited budget, strict timeline and desired size limitations.

Project Goals and Key Deliverables

Expected end result of the project, what the customer can expect to receive at the end of the project.

User Scenarios

1. Hot Wheelz Team Member who is looking to test their electro-mechanical design for a long duration of time. May be looking at battery drainage or heat generated during a long run.

2. Hot Wheelz Team Member who is looking to test their electro-mechanical system for a short amount of time. May be looking at maximum power output over a short period.

3. Hot Wheelz Team Member who is looking to test their electro-mechanical drive system on manual mode. May be looking to troubleshoot faults in their system design.

Customer Requirements (Needs)

Customer Requirement Description Importance
1 Electro-Mechanical Drive System transferable from the test bench to the Vehicle 3
2 The test bench is portable 9
3 Record and Log Performance parameters 9
4 Variable loading on the Electro-Mechanical Drive System 9
5 Electrically and Mechanical Safe for User 9
6 User Friendly Interface/ Simple to Operate 9
7 Targets faults in the system as they occur 3
8 Real time results are visible 9
9 Instruction manuals available to user 3
10 System has manual and automatic control features 1
11 Complies with all safety standards and rules in the Formula Hybrid SAE Rulebook 9

Engineering Requirements (Metrics & Specifications)

Engineering Requirement Description Corresponds to Customer Requirement Measure Value
1 Electro-Mechanical Drive System mimics layout on vehicle. 1 in +/- 2 mounting locations
2 Max Dimensions (Length, width, height not including space to mimic drive system layout) 2 ft < (6 X 4.5 X 5)
3 Max Weight (Excluding Vehicle electro-mechanical system) 2 lb <250lb
4 Software GUI will be Windows compatible. 3, 6 Binary NA
5 Vary the loading on drive system 4 lb-ft > EV motor
6 Calculate equivalent forces acting on car. (Need vehicle mass, rolling resistance, etc.) 4 lb TBD
7 Emergency Fail Safe 5 Binary At least 1
8 Correctly Rated Components 5 Watts for resistors, V/I for fuses, AWG for Wiring 25% > than expected wattage for resistors, 15% > I ratings than expected for fuses, 25% > V/I for wiring in addition to using a step up in AWG size.
9 Adheres to all safety standards and limits per Formula SAE Rules 5, 11 Binary Article EV3-EV9
10 Current Sensors with LED indicators to identify error for troubleshooting 7, 8 Binary 1/accumulator segment
11 Display graphical representations of data as it is being collected versus time. Parameters such as torque and power consumption 8 Binary Display measurable parameters intuitively
12 Detailed manual for usage including power up, power down, LOTO procedure and how results are outputed for further use 9 Binary Video/PDF
13 Have a manual system testing and control. Also have automatic features so that user can input simulation of a course and iterate through for long term testing on the system. 3, 10 Binary Type of simulation
14 Data transfers reliably 7,8 Bit error rate Ideally 0

Constraints and Current Gaps

1. Limited Budget- Budget is still unclear at this time

2. New project, no current design for the Hot Wheelz electro-mechanical drive system

3. Strict Timeline- Must adhere to MSD I and MSD II Timeline and also be completed in time to test the electro-mechanical system for the vehicle prior to competition

4. Interdependence between MSD team and Hot Wheelz Team-Unknown vehicle specifications

5. Size/ Weight Limits- Needs to fit into the Hot Wheelz Room

6. Availability of required power to run system

Solution Parking Lot

During the Problem Definition phase, you will start coming up with possible solutions. Rather than act on those now, put them in the Solution Parking Lot, and come back to them after your team has fully defined the problem.

Potential Solutions

Non contact laser tachometer to measure rotational speed

Servos attached to pedals to control motor acceleration

Magnetic braking to vary load

Shopping cart handle to move bench

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