Team Vision for Problem Definition Phase
- Better understand our project in terms of problem definitions and requirements
- Understand team skills and the best way to utilize them
- Develop a testbench that is fully capable of testing the Hot Wheelz vehicle’s electrical system
- Allow for universal mounting of components the team may change from year to year
- Permanently mount circuits that will remain the same from year to year
- Testbench must follow any applicable competition rules to ensure effective testing capability
- Defined our problem statement so it can be explained in detail or in simplistic terms
- Defined Engineering and Customer requirments
- Use Cases
- Preliminary schedule
- Defined team skills and values
Project SummaryProblem Summary
During the Preliminary Design Review phase, the primary use cases for the project were more clearly defined. The use cases for series and parallel powertrain configurations are shown below.
One aspect of reusing the test bench year to year is ensuring that it is able to test the different powertrain systems the Hot Wheelz team designs. This includes both parallel and series hybrid systems. To test series hybrid systems, the test bench needs to be able to load the motor on the dynamometer and test hybrid charging of the batteries. To test parallel hybrid systems, the test bench needs to be able to load the motor and load the engine independently on the dynamometer. Testing parallel hybrid systems does not include testing the mechanical drivetrain.
BenchmarkingThe image below shows a few benchmarking solutions for an electrical/hybrid test bench. The "No testing" option displays the worst-case solution and the "Suggested Design" option displays the best-case solution. A higher score correlates with a better solution.
Customer Requirements (Needs)
Customer InterviewGeneral description of project:
- Test bench which will be used to test all of the electrical systems on the current & future hybrid-electric vehicles
- Needs to test all circuits including shutdown, GLV, tractive system, charging system, and gen-set and telemetry
- Needs to be reusable and reconfigurable for other motors/engines in the future
- Don’t want to use parts from our car to make the test bench work → want to put tested components on it but not switches, buttons, etc.
- Include some sort of charging capabilities whether AC or DC
What is the most important feature you want this device to be able to support?
- Tractive system & gen-set (GLV and shutdown have been developed already so they’re not as important). Telemetry is important but it won’t greatly affect the competition
- Tractive/gen-set are most likely to fail or need development
- Gen-set: internal combustion engine, alternator/generator, conditioning electronics (rectifiers, etc.)
What amount of funds would be needed to make this project a reality?
- Need to include prices of alternators/engines to test the bench
What are your expectations in terms of the telemetry specs? (wireless range and data transfer)
- 100 feet
- Through dyno room
- Not line of sight
- if necessary have an antenna able to collect data from the other side of the wall
What is your vision for the GUI used to interact with test bench parameters? Should it be designed for end users?
- Not command line
- Mechanicals on team should be able to use and understand
- GUI gives meters (current flow, voltage, load if applicable)
- LED input for status of systems
What electrical systems can be permanently installed on the test bench?
- GLV system/power supply for GLV (12 or 24 V or switchable), tractive system energized lights and warning lights, BRBs, key switch, AIRs, convenient way to connect to the batteries, shutdown circuit
What kind of power sources do you need for the ground low voltage system and telemetry?
- Preferably switchable 12/24V
Where do you plan on using the device?
- Should fit in the elevator
- Be able to travel between shop, sr design floor, and team room
- Needs to be able to go through a regular, single door
What elements of the Hot Wheelz car design affects our ability to create the test bench?
- Need to determine power requirements on gen-set and then can pick a generator
- Power requirements/ rules for battery packs
What issues need to be addressed in regards to the previous test bench?
- Wiring and connections were messy. Wired to a standard (NFPA)
- Put electronics inside housings. Switches can be on doors of those panels
- Plastic electronics housings
What kind of data is important to collect from electrical testing?
- Current, voltage, where in shutdown system we have voltage (for finding faults), temperature, motor control (type of acceleration we’re getting → maybe for loading), feedback from motor performance, temp of batteries, state of charge (esp. If we can load the motor), how fast we’re charging batteries, current everything is pulling
- Be able to test IMD and latching circuits
Engineering Requirements (Metrics & Specifications)
- $4000 budget
- 2018 Formula Hybrid Rules
- Maximum width in accordance with smallest doors in KGCOE
- Tractive system components must be isolated and present minimum risk
House of Quality
Design Review Materials
Plans for next phase
- Refine Engineering Requirements
- Gather data needed for benchmarking design
- Functional decomposition
- Block diagram of all electrical systems
- Basic mechanical sketches/models
- Preliminary test plan
- Cost breakdown