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BiPed Creativity Exercise

Csulb EE 400D 2/15/2017

Alexander Clavel / Project Manager

Jacob Cheney / Missions, Systems, and Test

Abraham Falcon / Electronics and Control

Phong Nguyen / Manufacturing

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Identifying Problems

Create a small list of problems with the current design then apply the creativity tool methods to come up with possible solutions

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  1. How to control the shift in Center of Gravity
  2. How should we design the legs
  3. How to keep the feet from slipping
  4. How to turn the BiPed
  5. How to control walking with 1 or 2 DC motors

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Some outside influences

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Method 1: Brainstorming Approach

  • All ideas are encouraged
  • Write down as many ideas as possible
  • After a break, combine and improve ideas.
  • Delay judgement and evaluation of ideas until end...

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#1 - How to control shift in CoG

  • Servo on ankles to tilt
  • Use arms to counterbalance
  • Build the robot to accurately mimic a human body
  • Teeter tot
  • Bend at the knee to angle the body

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#2 - How should we design the legs

  • Build it proportional to human legs
  • Add a spring or shock absorber to the legs or foot
  • Put DC motors on the outside and bring legs closer in together
  • Curve feet for better balance
  • Use light but sturdy material to build from
  • Straight legs like a human
  • Inverted legs like a dinosaur

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#3 - How to keep the feet from slipping

  • Add skate board tape to the bottom of the foot
  • Add a texture pattern on the bottom like the soles on shoes or tread on tires
  • Attach rubber to the either part or all of the underside for the foot
  • Create the feet with any type of high friction material

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#4 - How to turn the BiPed

  • Rotate ankle joint
  • Rotate knee joint
  • Rotate hip joint
  • Use a back and forth motion to eventually turn

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#5 - How to control walking with DC motors

  • Use 1 DC motor total and crankshaft with chain(s)/belt(s) to control both legs simultaneously. Other joints controlled with servos
  • Move each leg individually with 1 DC motor each. Other joints controlled with servos
  • Control all joints and legs with individual DC motors. No servos

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Method 2: Attributes

We took a look at the different parts of the robot separately and then were better able to think of creative paths to take when designing the robot.

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  • Color
    • Any color
    • Transparent
    • Skins
    • Stickers
  • Control Device
    • Phone app (android/iphone)
    • Arxterra Control
    • Switch
    • Controlled by PS4

  • Material
    • Graphite
    • Aluminum
    • Metal
    • Plastic
    • Wood
    • PCP Pipe
    • Styrofoam
    • Crystal

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  • Shape
    • Stars AT-ST
    • Human Figure
    • Block Design
    • Straight Legs
    • Inverted Legs
  • Sounds
    • Typical Robot Sounds
    • Star Wars Theme Song/Soundtrack
    • Robotic beeps
    • Laser Fire
  • Features
    • Color Coordinated Walks
    • Pad Recognition
    • Noises
    • Turning
    • Squatting
    • Dynamic Walking
    • Static walking

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Color and Material

Black Plastic - Aluminum

Control device

Phone apps

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Shape

inverted legs

Sound

Features

Robot beep:

20 Hz - 20,000 Hz

Biped _ Static walking

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Method 3: Forced Relationship

Here we used the random noun generator to associate and relate different parts of the robot with random items.

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Underwire

  • Use wires to support areas that bend (knees or ankle)
  • Use a moving ball weight on an underwire to counteract shift in CoG
  • Design a curve in the feet

Rocking Chair

  • Sturdy, made of wood
  • Balanced, rocks to equilibrium
  • Curved

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Truck

  • Wheel traction (rubber)
  • Front/Rear wheel drive
  • Diesel fuel
  • Large, heavy, low center of mass
  • Can attach/detach cargo

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Method 4: Dunker Diagram

To come up with new ideas, we took a look at a desired goal and how to achieve it. Then we looked at solutions where it was ok to NOT meet the desired goal.

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Problem (Present State):

Most Biped walk with Servos as the main movement.

Desired State:

Find a Better Movement for the biped to walk.

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Make it not okay to use servos for the movement

Use Two DC Motors

Use Servos for the movement

Two Servos for the legs and Two for Ankles

Each Legs to have a DC Motor

Two Servos for the hips and two for the ankle

Use One DC Motor

Use Four Servos

Use Two Servos

Each Hips to have a DC Motor

New Problem Statement

Desired State

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Method 5: Different Point of View

Here we took a look at the robot features from different perspectives or out of the box ideas.

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Points of View

I am the Robot

  • I would like to be repairable
  • I would like to have attachable/detachable parts
  • I would like to be strong and durable
  • I would like to have rotatable hips
  • I would like to be light to take stress off my joints
  • I would like to be able to get back up if I fall
  • I would like to be waterproof/heatproof
  • I would like to be decently fast

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Points of View

Made from common items found at home

  • Feet could be made from shoes
  • Legs and arms could be made from rolled up

aluminum or silverware

  • Made from repurposed wood
  • Legos used for body parts

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Point of View

Robot on the Moon

  • Should have slower more careful movement
  • Boosters or stabilizers to stay balanced
  • Some kind of spikes or clamps on the feet
  • Need to traverse possible inclines and declines

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Points of View

In the future

  • Incredibly strong
  • Very human-like motion
  • Sensors to be able to react like humans do
  • Artificial intelligence
  • Portable beer cooler or instant food storage
  • Skin and hair
  • Autonomous and controllable through conversation
  • Medical functions

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Proposed Solutions

Using the different creative methods to come up with solutions for the different problems

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How to control shift in Center of Gravity

Solution 1: Brainstorming

Idea: As soon as one leg is lifted the robot would lose balance and tip over. Having the robot bend over the ankle joint would keep the center of gravity in a suitable position.

Questions: How to get the weight over the ankle and the shifting it back over for the next step, using servos as in previous projects

Experiment: Conduct load analysis for servos to see what strength and weight is needed to make it work, then test them.

Solution 2: Brainstorming

Idea: Use arms to lift them up to the sides while the robot is taking steps to counteract the weight shift

Questions: How heavy and how big should the legs be? How would we move them?

Experiment: We could use servos to rotate the arms up and test the robot with the attached limbs or connect them to the dc motor through a crank to move simultaneously as the legs.

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How should we design the legs

Solution 2: Brainstorming

Idea: Bring the legs closer together and put the dc motors either on top or outside of the legs as opposed to last semesters

Questions: What does moving the leg positions closer together do for the shift in center of gravity

Experiment: Build a rapid prototype and see how far over the how robot will have to lean to stay balanced over the ankle. Or use a program to simulate the physics of the system.

Solution 1: Dunker

Idea: Use two DC motors. One in each leg to control the walking motion.

Questions: How would the DC motors be positioned on their respected leg? Would they be positioned vertically or horizontally? High on the leg or low on the leg?

Experiment: Build a prototype and position the DC motors on various parts of the leg vertically and horizontally to see which way compliments our design the most. Also determine how positioning affects COG.

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How do we keep the feet from slipping

Solution 2: Different Point of View

Idea: Have a separate attachable foot piece that is designed to specifically have better grip than the default foot.

Questions: How will the foot piece be attached? Would it be glued or screwed on permanently? Or something that you can detach and reattach depending on the walking surface type?

Experiment: Conduct friction tests to see how certain materials grip onto different walking surfaces. For example rubber on concrete or sandpaper on carpet.

Solution 1: Forced Relationships

Idea: Relating truck wheels to a robot we can put some kind of rubber on the bottom of the foot.

Questions: How much rubber should be applied to the area of the foot? How thin? Only partial coverage or full? What other material can be used? Will it affect the walking aspect at all?

Experiment: We can purchase different material samples and test their grip on smooth, rough, and slippery surfaces as well as inclines and declines to see how well they work.

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How to turn the robot

Solution 1: Brainstorming

Idea: Follow the previous semesters idea of rotating a joint on the leg (preferably the ankle) on a horizontal plane to achieve a left, right or 180 degree turn.

Questions: How much of a load would be on servos? Would ankles be used for turning only or also for controlling center of gravity? How will the turn be controlled remotely?

Experiment Conduct load analysis and test the actual servo to make sure that it can actually handle the weight on it. Determine which joints (if any) can handle the load.

Solution 2: Forced Relationship

Idea: Use a back and forth style motion to turn the robot in any direction.

Questions: How will we implement the code to achieve this style of walking? How long will it take to turn if it has to keep going back and forth? How much room will it need to completely turn around?

Experiment: Play around with coding on prototype to see if turning is possible and practical to achieve turning without adding any extra moving parts.

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How to control walking with DC motors

Solution 1: Brainstorming

Idea: Use one DC motor with crankshaft to control both legs simultaneously

Questions: How will we translate the energy from one spinning rod to move two legs at the same time? Can one DC motor provide enough torque for two legs?

Experiment: Prototype with a crankshaft and a belt/chain to create a static walk

Solution 2: Brainstorming

Idea: Use two Dc motors to control both legs independently

Questions: How will our embedded processor control both motors at the same time? How much weight does an additional DC motor add to system?

Experiment: Develop simple program to explore capabilities of having dual DC motors