Team Vision for System-Level Design PhaseDuring the Systems Design phase, our team had the goal of completing all assigned tasks and deliverables. These items included our functional decomposition, benchmarking documents, phase-appropriate feasibility, concept generation, systems architecture, and risk assessment. A challenge we faced early on in this phase was working through another iteration of our use cases from the problem definition phase. Through further refining our use cases to more accurately match our customer and engineering requirements, we were able to provide accurate details into our functional decomposition.
Functional DecompositionTo further understand the scope of our systems design, a high level functional decomposition was created. As a team, we identified necessary inputs with their desired outputs to aid us in the creation of our functional decomposition. The Functional Decomposition image traces through what actions are utilized through use of the model railroad system.
Engineering Requirements Mapping
BenchmarkingThe below images depict our benchmarking analysis for our two main deliverables, the modular control panel circuit prototype and the new layout brain. The products were selected based off of functionality for a model railroad system. The modular control panel circuit prototype was benchmarked against control panels, and the orange sections highlight what products are currently in use within RIT's Model Railroad Club system. The new layout brain was benchmarked against microcontrollers because the design we create will be a microcontroller, as requested by the customer. The below table titled New Layout Brain Microcontroller Benchmarking displays various options of microcontrollers in the market we could utilize for our system design.
Morphological Chart and Concept Selection
Concept SelectionSelection Criteria:
- Feasible for team to implement
- Reliable to transmit information (ie./ signals and commands)
- Easy to integrate with existing systems
- Easy to modify
- Aligns with customer requirements
Feasibility: Prototyping, Analysis, Simulationthis document
Systems ArchitectureCommand Station
- RS-232 is only free port for future connection
- Will communicate with Layout Control Brain over new communication Bus
Layout Control Brain
- Will handle signal logic, remote interface, and communication with the control panel controllers
- Raspberry Pi is current concept choice
Control Panel Controller
- Raspberry Pi Zero is current concept choice
- USB based communication bus. May be subject to change based on club feedback
- Existing control panel will be starting point for testing
- New control panels will be created to test various turnout and interlocking combinations
- Raspberry Pi Zero to handle local control, block detection, and signaling.
- Custom PCB shield for Raspberry Pi Zero with terminals for wire connection points
Risk AssessmentWithin our risk register, we assigned all risks with a letter code. The risks we identified were based off of a 1-3-9 rating, 1 being least severe to 9 being most severe. The ratings were given to the severity of the risk and the likelihood of the risk occurring.
A risk register graph was created to depict where the majority of our risks fall in terms of severity and likelihood, as well as if any risks are added or deleted out.
To view risks with respect to their letter codes, please reference our risk register which can be found here.
Design Review MaterialsP19345 System Design Review Powerpoint
Plans for next phase
As we go into the next phase, we will expand upon the referenced tasks to include all necessary actions required to complete them.
- Marianna Palacios - Three-Week Plan
- Derek Schwartz - Three-Week Plan
- Denisse Aquino - Three-Week Plan