Page tree
Skip to end of metadata
Go to start of metadata


Team Vision for Detailed Design Phase

Our goals for this phase of MSD were to continue our work from Preliminary Detailed Design, and finalize our designs for implementing the systems and concepts that we have identified. This was accomplished through the following tasks that we planned to do during this phase: 

  • Make final selections, based on feasibility analysis, for critical electrical components, such as a battery, motor, motor driver, etc.
  • Purchase selected parts.
  • Create electrical schematic based on the aforementioned parts and components used during proof of concept in Preliminary Detailed Design.
  • Create CAD models for tiller attachment, mechanical tiller control, and user interface.
  • Build a test-bench with Rochester Yacht Club's spare tiller, modeled after the back of a sonar.
  • Determine where our project funding will be coming from. 

Our team accomplished the following:

  • Selections made on a 12V CIM PMDC motor, a 30A brushed DC motor driver, 12V sealed lead acid batteries, and power regulators, and encoders. 
  • Electrical schematics created for motor control and user feedback
  • CAD models created for tiller attachment, user interface and test-bench modeled after the back of a sonar
  • Received positive notes for RTC members saying they would like to contribute to our project

Progress Report

Below is a snapshot of the tasks which were assigned and accomplished throughout MSDl (taken from TeamGantt). At the end of the Detailed Design phase, the SailBot project is on schedule and projected to begin building and testing prototypes at the start of MSDll. Some tasks, marked by less than 100% completion, were listed with the intent of beginning them during MSDl in order to get a head start on the deadlines for MSDll.

Mechanical: CAD models have been made for the tiller attachment and testing rig. Both will hold top priority when beginning to build in the next phase so a first round of testing can be done on them.

Financial: Financial proposals were sent to many potential sponsors and responses have been received from them. Components such as an old tiller, used motors and wheelchair parts have been donated as well as funding from RYC. The BOM currently reflects the first purchase order made for electrical components and will continue to be updated with each upcoming purchase. 

RIT Deliverables: Confluence is up to date with all the work that was accomplished during the four phases of MSDl. Risks and requirements will continue to be updated with any design changes or added customer desires. 

Electrical: Programming for the controls and wireless communications was done as well as proof of concept tests with an arduino that was purchased. This system will be fine tuned and linked with the feedback systems in the next phase.

Industrial/ user controls: The layout and look of the user controls was sketched and a CAD model was made. Feedback displays have also been decided on. A survey being sent to sailors with disabilities is in the works and will be used in preparation for building the SailBot controls to ensure user comfort and ease of use is achieved.



Prototyping, Drawings, Engineering Analysis, Simulation

Mechanical

CAD model of SailBot with tiller attachment. SailBot will be attached in the back left corner of the Sonar and will attach to the tiller via a lead screw. An indentation in the top of the casing will provide a place to store or set the user controls. The image on the left includes the battery (represented by the blue box). All of the other electrical components will be housed in a separate compartment along the back of the case (located at the red oval) for better water proofing. Some of the gearbox and linkage specifications are listed below:

  • 40:1 gear ratio

  • Works in 20 knot wind

  • Travels 80 degrees in 3.2 s


The tiller emergency release will be composed of a quick detachment such as the one modeled below. When pushed down, a spring will release and the pin will slide out.


A test bench which will utilize the donated tiller and a wooden replica of the back of a Sonar was also modeled. This test rig will have the following specifications:

  • 120 lb Gas shock 

  • Compression simulates waters force to return tiller to straight

  • 421.5’ of 2x4 wood

Electrical Prototyping

Continuing the prototyping from the preliminary detailed design phase, further tasks were identified which must have prototypes developed. The tasks developed to confirm proper functionality are listed as follows:

  1. Wireless Override
  2. DC Motor Control
  3. Encoder Based Speed Monitoring
  4. Hall Effect Based Limit Switches
  5. Battery Voltage Monitoring
  6. Real Value User Feedback

The following schematics depict how the master Arduino and slave Arduino will be built. The master Arduino, powered by a 9-volt battery, will be used by the user to control the slave Arduino, powered by the 12-volt lead-acid battery, which will provide user feedback to the master as well as control the motor and motor driver: 

Master Arduino Schematic



Slave Arduino Schematic


The code implemented for these circuits is complete but as of yet untested. Diagrams which display the functionality of the code are seen below.

Master Arduino Code



Slave Arduino Code


User Interface


The drawing and CAD model below shows the concept that was chosen for the user interface and controls. A platform will sit on the sailor's lap and will have straps which can either be secured around their waist or legs to hold it in place. 



The feedback displays (compass, tiller direction, battery life, and race timer) will be located in the back half of the platform and will be able to be tilted up, similar to a laptop screen, in order to increase visibility for individuals with limited head and neck mobility. LED's will be used instead of a screen to display tiller direction and battery life to maximize viability in sunny conditions.


Bill of Material (BOM)

Our Bill of Material was constructed in accordance with our feasibility analysis, simulations, and the engineering and customer requirements. It was updated during this phase to reflect the first purchase order made for some of the electrical components needed for testing.


Test Plans

The following tests will be conducted in MSDll as proof of concept and confirmation that all customer and engineering requirements are met. Related risks are listed with each test to ensure each risk is considered as we move forward to building SailBot.

Force Test

  • Purpose: To simulate forces of water acting on tiller

  • Related Risks: 4, 5, 8, 10, 13

  • Materials needed (besides SailBot)

    • Force Gauge

    • Spring

    • Wooden model of sonar back half 

    • Tiller

    • Timer

  • Systems that must be completed to perform test

    • SailBot Tiller movement

    • SailBot Electrics (motor)

    • No need for wireless communication or controller

  • Basic Procedure

    • Hook up spring to tiller.

    • Turn SailBot all the way to port (record turning time)

    • Ensure correct force (400 Nm) to simulate water

    • Hold for 10 second

    • Turn SailBot all the way to Stbd (record turning time)

    • Ensure correct force (400 Nm) to simulate water

    • Hold for 10 second

    • Return to center

  • Estimated time: 30 seconds

  • Number of times to repeat: 20

  • Total time required: 10 minutes

  • Alternative versions to test

    • Have SailBot say on one side based off gearing- requires no motor control


Battery Life Test

  • Purpose: Ensure that SailBot can last a two hour session. This includes battery, motor, and mechanical life

  • Estimated time: 2 hours

  • Number of times to repeat: 3

  • Total time required: 6 hours

  • Related Risks: 6, 11, 13

  • Material needed (besides SailBot): 

    • Battery

    • Oscilloscope or Voltmeter

    • Equivalent load to motor at max torque

  • Systems on SailBot that must get done: 

    • Arduino Motor Control

    • Motor selected

  • Basic Procedure: 

    • Connect battery to equivalent load. 

    • Run test for 2 hours.

      • Measure the voltage/current level of the battery every 15 minutes or continuously if possible

    • Stop test when motor stops moving or at 2 hours

    • Calculated battery life based the voltage/current drop

  • Alternate versions of procedure:

    • Use a battery life calculation based on the load amperage

    • Test just battery or just mechanical components


Water Test

  • Purpose: Ensure water resistance

  • Estimated time: 2 minutes

  • Number of times to repeat: 3

  • Total time required: 6 minutes

  • Related Risks: 2, 5

  • Material needed (besides SailBot):

    • Spray bottle filled with water

  • Systems on SailBot that must get done:

    • SailBot electronics enclosure

    • SailBot carrying case

    • SailBot user controls

  • Basic Procedure:

    • Spray the SailBot carrying case and electronics enclosure with water, enough to saturate all exposed surfaces.

    • Open the case and ensure all components are dry inside

    • Spray the user controls with water

    • Connect the user controls and ensure they function correctly by steering to port and starboard 

  • Alternate versions of procedure: 

    • Repeat with all user control methods


General use test

  • Purpose: Ensure SailBot functions correctly as a unit (without need for overrides)

  • Estimated time: 30 seconds

  • Number of times to repeat: 10 (with each user control method)

  • Total time required: 30 minutes (per method)

  • Related Risks: 8, 9, 10, 13

  • Material needed (besides SailBot):

    • Stopwatch

  • Systems on SailBot that must get done: 

    • SailBot tiller attachment

    • SailBot electronics

    • Wireless communication with user controls

  • Basic Procedure:

    • Hook up SailBot to the tiller

    • Connect the first user input method

    • Turn SailBot all the way to port (record turning time for reference)

    • Let go of SailBot and ensure it returns to center with no applied user input

    • Turn SailBot all the way to starboard (record turning time for reference)

    • Let go of SailBot and ensure it returns to center with no applied user input

  • Alternate versions of procedure:

    • Repeat the same procedure using each of the different control methods

    • Test SailBot in varying weather conditions


Emergency Override tests

  • Purpose: Ensure that emergency release works correctly always

  • Estimated time: 2 minutes

  • Number of times to repeat: 3

  • Total time required: 6 minutes

  • Related Risks: 17

  • Material needed (besides SailBot):

  • Systems on SailBot that must get done:

    • Emergency override

    • SailBot tiller attachment

  • Basic Procedure:

    • Connect SailBot to the tiller

    • Move the tiller all the way to port

    • Employ the emergency quick release and ensure the tiller can be fully used manually without SailBot

    • Reconnect SailBot and move the tiller all the way to starboard

    • Again, employ the emergency quick release and ensure the tiller can be fully used manually without SailBot

    • Repeat a third time, this time starting with the tiller at canter


User test

  • Purpose: Ensure controls are comfortable and easy to use, SailBot clearly displays its information

  • Estimated time: 30 seconds

  • Number of times to repeat: 3 (with each user control method)

  • Total time required: 1.5 minutes (per method)

  • Related Risks: 7, 12, 14, 16

  • Material needed (besides SailBot):

    • People

  • Systems on SailBot that must get done:

    • All user input controls

    • Wireless communication with user controls

  • Basic Procedure:

    • Connect the first user control method to SailBot

    • Confirm that the battery life is clearly displayed

    • Confirm that the race clock/timer is clearly displayed

    • Have the user steer to port, back to center and to starboard

      • Confirm that the tiller direction feedback displays the correct direction for each position

    • Ask the user to rate their comfort level and the ease of use

  • Alternate versions of procedure:

    • Repeat the same procedure using each of the different control methods

Risk Assessment

During this detailed design phase, no changes were made to the risk analysis chart. Although more prospective sponsors have shown interest in providing funds and parts to the project, our budget and spending still continue to pose as a considerable risk. The work accomplished throughout MSDl has our team on track moving into MSDll and there is no concern for the risk of not completing on time.



Design Review Materials

Include links to:

Plans for next phase

  • Build a test-bench modeled after the back of a sonar
  • Start building tiller attachment prototypes and testing them on the test-bench
  • Revise test plans and add any additional test needed for each subsystem
  • Make another larger purchase order for mechanical and user interface components and materials
  • Transition the risk assessment chart to problem tracking if/when issues come up 
  • Continue communication with all sponsors (RYC, Monroe Wheelchair, SEAS) 
  • Send out user survey to sailors with disabilities to get feedback on SailBot controls


Below are the three-week plans for each individual team member of the next phase:

Amit Rogel

Matthew Miller

Max Messie

Mike Robinson

Thomas Davis

Erica Kabat


  • No labels