Team Vision for System-Level Design Phase
During this phase, the team planned to gain a broad understanding of all of the functions that this test bench will be able to perform and to complete a feasibility analysis to guide further design. The team also planned to gain a better understanding of the hybrid systems that the test bench can accommodate in order to allocate space and set up necessary configurations on the test bench for these systems. Finally, the team planned to brainstorm and select concepts for the major systems and functions of the test bench.
Major concepts were brainstormed using a morphological chart during this phase and decision matrices were utilized to analyze these options. A top choice for each function of the test bench was selected, and the team ensured that these choices could be integrated together.
Benchmarking and Research
Hold ComponentsEach option was researched to determine its usefulness and feasibility for our application. Results are summarized in the chart shown below.
Communication Between Devices
Connection To Host
Hybrid ComponentsBelow are common hybrid components the bench may need to accommodate for:
Our functional decomposition generated eight main functions for us to design to. To make our decisions we developed a Morphological Chart and created decision matrices for each.Morphological Chart
Feasibility: Prototyping, Analysis, SimulationAnalysis of expected weight requirements for the bench
Deflection analysis for a quarter inch thick aluminum pegboard mounted as the base of the cart using max component weight approximation. Components will be mounted to the pegboard base using nuts and bolts.
Design matrix for cart frame material selection
Design matrix for microcontroller selection
Server vs Node to Node Implementation User Flow
Wiring StandardsWiring Standards
Microcontroller StorageMinimum Onboard Storage Calculations
Data Rate CalculationMinimum Data Rate Calculations
Software Flow ChartsFlow for editing CAN bus definitions
Flow for deleting CAN bus definitions
Flow for creating new CAN bus definitions
Where CAN Definition Entry fields consist of:
- Bitwise Fault Indication
- Component Type (Controller, BMS, ECU, Thermistor, etc.)
- Parameter Name
- Frame ID
- Frame Length
- Parameter Data Length
- Scaling Factors and Operations (For Calibration Purposes)
- Offset (For Calibration Purposes)
- Parameter Units
- Minimum "No Fault Range" (Minimum value to not indicate fault)
- Maximum "No Fault Range" (Maximum value to not indicate fault)
- Parameter Index Selection
- Big/Little Endian Indication
Flow for displaying data
Flow for logging data
Concept Development & Concept Selection
Based on the outcome of our decision matrices, we used the top candidates to build 5 different concepts to compare against the current test bench system used by the Hot Wheelz team.
We used the following criteria to compare the concepts against each other using Pugh Charts
At this point, we have not found any conflicts between the different concepts that have been selected. As designs are created in more detail, conflicts will be tracked and noted. For the Detailed Design Review, we will ensure that all conflicts have a plan for mitigation.
- Concept 3, 4 and 5 had a more negatives than positives for each of the three datum changes.
-Based on the feasibility analysis it was decided that several power sources and items would not fit on the cart due to space constraints
-Concept 4 was removed due to the extreme un-feasibility of utilizing nuclear power.
-Concept 6 was our do nothing solution and in nearly ever case utilizing some improvement caused the other concepts to score better
-Concept 1 is the strongest because it is the most convenient method in terms of space and power utilization.
Systems ArchitectureThe image below displays an overall system architecture of the entire project. The second Image displays a more detailed architecture of the electrical system. In the electrical system architecture there are two 12V power sources: one for the bench supply and one from the Hot Wheelz Design. The bench supply will always power sensors and telemetry. There will be a switch with the option to test Hot Wheelz GLV systems with the bench supply or the team designed supply. This allows the team to test their power designs or just use the bench supply for convenience.
Designs and Flowcharts
A working version of the risk assesment table can be found in the following link: Risk Management
Design Review Materials
Our systems level design presentation can be found here
Plans for next phase
For the next phase, our team plans to continue using feasibility analysis and engineering analysis to complete a preliminary detailed design. This design will include a parts list displayed via a Bill of Materials, software design, and test plans to demonstrate that the Engineering Requirements have been satisfied by our design. By the end of the next phase, a preliminary budget will be outlined with costs for each component.