Table of Contents
Team Vision for System-Level Design PhaseThe team's goal for this phase was to select the building blocks that would shape the design of the assembly. This meant discovering a finalized location for the assembly so that it could be determined whether the assembly could be powered via an external source or require it's own means of power generation.
This also meant benchmarking of motors and frames to develop a proper idea on how to move the antenna and guard the components against the elements.
While confirmation of availability has been reserved for after a preliminary design has been completed, the team found that the assembly could likely be set up at the RIT Observatory where power outlets and a hardline internet connection should be readily available. Towards this end, preliminary CADD models have been created detailing the plans for the mechanical aspect of the assembly.
Concept DevelopmentIn order to develop concepts that would satisfy our design requirements and function optimally, we had to go back and re-benchmark and identify additional products that perform a similar function to our project. We also had to identify subsystems and various components that would be used in each subsystem (achieved with functional decomposition combined with feasibility). Lastly, we needed to ensure that we were not forgetting about the customer requirements, engineering requirements, and constraints to meet the goals defined in the problem definition phase of this project. After analyzing benchmarks, subsystems, and design requirements, we brainstormed the following solutions that would satisfy the deliverables outlined during the problem definition phase:
- Concept 1: Triaxial movement using pedestal and triangular supports.
- Concept 2: Triaxial double-plated pedestal using symmetric column supports.
- Concept 3: Biaxial movement using belt-driven gear system to rotate bottom portion.
- Concept 4: Biaxial worm-gear-driven system requiring stationary motors.
- Concept 5: Triaxial pneumatically-driven system.
- Concept 6: Triaxial speherical movement (like a mouse-ball on a computer mouse).
Feasibility: Prototyping, Analysis, Simulation
- Is motor torque sufficient?
- How much energy is required to move the system?
- How will mechanical performance be affected over temperature?
- Confirm that motor driver can drive motor
- Characterize motor parameters
- Measure power consumption under worst case
- Generate simulated sensor data, so we can run repeated test on motor movement
- Measure accuracy and sensitivity of DOF sensor
- Pseudocode for firmware
- Test and refine serial communication between Pi and Arduino
- Test network and remote access setup
- Configuration of Linux/Raspbian
- Measure power consumption and heat output under worst-case load
- Pseudocode for firmware
Morphological Chart and Concept Selection
Concept SelectionThis consists of two elements:
- Concept Screening: Identify 6-10 useful system-level selection criteria, and evaluate the system designs objectively. Compare your system concepts to a single datum concept. Run your selection analysis multiple times to uncover saturated scores.
- Concept Improvement: Look for opportunities to combine two or more promising system concepts to create an even better solution. You may need to repeat these steps several times in order to converge on an optimal solution.
The real value in this step of the process is not the comparison matrix you generate to compare your concepts, but the analysis and discussion you do to support your evaluation.
Design Review MaterialsPre-Read for Design Review Presentation
Plans for next phase
- Complete BOM and begin purchasing required materials.
- Continue Feasibility Testing.
- Create dimensioned drawing of mechanical assembly.
- Generate pseudocode and/or prototype user interface.
- Acquire express approval to install assembly at observatory and prepare allotted space to be used.