P18227: Soft Robot 2.0
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Detailed Design

Table of Contents

Team Vision for Detailed Design Phase

By this review, our team planned to complete all subsystem designs. This includes a more thorough look at our lower risk subsystems of communications, controls, and drive train as well as addressing the concerns raised by our preliminary detailed design review, including a reassessment of risks particularly in the tether and spooling system. We also planned to have all of our materials ordered and testing plans finalized in preparation for MSD II.

Progress Report

On 11/22, we completed a progress report outlining our plans and updates for this phase. Major points of interest included:

The report can be viewed here.

Robot System

Leg Chambers

The articulating leg chambers have a segmented design to allow for inflation and assist in articulation. The articulation chambers and foot-pad will be printed out of NinjaTek flexible 3D printing filament and the star-of-David shaped chamber plate will be 3D printed in PLA or ABS.
Snapshot of Leg Assembly Drawing

Snapshot of Leg Assembly Drawing


Robot Assembly

The complete robot assembly is composed to four legs and a chassis, which will be 3D printed in PLA or ABS. The tether will feed through the hole in the top of the chassis and separate into its component lines, which will connect to the holes on the interior faces of the chassis (visible in rendering below). The legs will be affixed to the chassis by small bolts threaded into collars press fit into the chassis.
Snapshot of Robot Assembly Drawing

Snapshot of Robot Assembly Drawing

Robot Assembly CAD

Robot Assembly CAD

Robot Assembly CAD

Robot Assembly CAD


Pneumatics System

Pneumatics Schematic

Pneumatic System Schematic

Pneumatic System Schematic

Spool Subsystem Detailed Sketches

Deploy and Attach System

Deploy and Attach System

Mate-Lock Bracket

Mate-Lock Bracket

Spool Cutaway

Spool Cutaway

Pneumatic System Schematic

Pneumatic System Schematic

Pneumatic System Schematic

Pneumatic System Schematic


Electrical System

Overview

The full electrical system is shown in the image below:
Full Electrical Schematic

Full Electrical Schematic

Control Circuit

The control of the RC system and the spool wheel are shown in the following circuit:
Power Supply Circuit

Power Supply Circuit

PDDR Circuits

From the preliminary design review, the power supply, valves, and microcompressors schematics are shown below:
Power Supply Circuit

Power Supply Circuit

Valve Control Circuit

Valve Control Circuit

Microcompressor Control Circuit

Microcompressor Control Circuit


Gait Sequence

The research produced by the UCSD team revealed that different gaits produced different performance of speed and stability. The following gate showed was reported by the UCSD team as the most stable:
(Left) Gait Sequence (Right) Actuation Sequence

(Left) Gait Sequence (Right) Actuation Sequence

The gait sequence (Left) indicates which leg is on the ground (blue) and which leg is in the air (white) during the sequence. The actuation sequence (Right) shows which chambers on a particular leg are in actuation pressure (blue) and which chambers are at standing pressure (white) during the sequence.

RC

The following diagram shows the sketch of the RC frame. The two motors will be belted to the 2 wheels on each side. If the funds become available from the IEEE grant, we will purchase 2 more motors and have 4 wheel differential drive.
RC Sketch

RC Sketch

Bill of Material (BOM)

Our Bill of Materials has been updated.

Our overall total cost of the system so far is $535.01. We still need to determine the costs of the frame of the RC, the side latch of the spool, and the mount which feeds the spool out. We are pursuing an IEEE grant.

Snapshot of purchased materials from Bill of Materials

Snapshot of purchased materials from Bill of Materials

Test Plans

Test plans have been completed and can be viewed here.

Leg Assembly

Leg Assembly Test Plans

Leg Assembly Test Plans

Pneumatics System

Electrical System

OptoIsolator Stress Test
  1. Connect 5V supply to input of optoisolator with push button and VCC of optoisolator
  2. Connect 5V supply to input of optoisolator with push button and VCC of optoisolator
  3. Connect 30V across solenoid valve and MOSFET in series
  4. Connect oscilloscope channel 1 across input of optoisolator and channel 2 across the output of optoisolator
  5. Rapidly press control button and record any voltage spikes

Setup Diagram:

Optoisolator Test Plan

Optoisolator Test Plan

Valve Triggering Test

  1. Connect the Arduino Mega to optoisolator and MOSFET circuits on the breadboard
  2. Connect air hoses to the inputs on each of the valves on the manifold
  3. Connect the air hoses to 3 psi air line
  4. Tape strips of paper over the output of each valve so that they hang over the output valve
  5. Start Arduino code for gait pattern and confirm that the air is blowing out of the appropriate valves by observing the paper lifting above the pressurized valves

Setup Diagram:

Valve Triggering Test Plan

Valve Triggering Test Plan

Communication Network Test

Battery and Power System Test

Deploy/Attach System

Deploy and Attach System Test

The spreadsheet of Customer and Engineering Requirements can also be downloaded for viewing here.

Design and Flowcharts

Revised Functional Decomposition Diagram

Revised Functional Decomposition Diagram

Risk Assessment

Our Risk Assessment has been updated.

The Risk Assessment Chart has been updated to now include risks that are relevant to the updates made to the design of the robot. These include a risk involving if our mode of printing our legs is not available, a risk involving our spooling system, and a risk involving our deployment of the robot. A risk involving the robot's regulators and valves has been moved from a high risk to a medium risk.

Snapshot of our updated Risk Assessment Chart

Snapshot of our updated Risk Assessment Chart

Design Review Materials

A summary handout will be available at our review and can be downloaded here.

Imagine RIT

Our Imagine RIT Outline has been created.
Snapshot of our outlined Imagine exhibit

Snapshot of our outlined Imagine exhibit

Plans for MSD II

Preliminary Gantt Chart for MSD II

Preliminary Gantt Chart for MSD II

Individual Plans:

Role Individual Plan
Project Manager Conor McKaig
Lead Engineer Zach DiLego
Electrical Engineer Cameron Taylor
Software Engineer Sean Bayley
Hardware Engineer Zach Hayes
Purchasing & Materials Marie McCartan
Comm. & Customer Contact Jamie Mortensen

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