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Senior Design Project Data Sheet
Project #
13212
Start Term
2012-1
Project Name
Colisionless Rimless Wheel
(Wireless)
Team Guide
Les Moore
Project Track
Vehicle Systems
Project Family
Collisionless Rimless Wheel
Project Sponsor
FEAD grant
Doc. Revision
1.00
Project Description
Deliverables:
9.
Project Background:
We aim to construct the most energy-efficient,
four spoke rimless wheel that can sustain periodic
motion. This project will help understand how to evolve
robot movement because our end product will
demonstrate continuous collision-less motion by
eliminating energy loss between the feet (in this case
spokes) and the ground, which is currently the primary
source of inefficiency in walking robots.
Dr. Gomes’ unpowered 5 spoke rimless
wheel demonstrates edges walking on a flat surface
with periodic rotating motion and energy loss as a
wheel. We will be using Gomes’s existing model to help
understand and achieve our goals.
It is also observed that high interest in
walking robots exists and therefore previous research
has tried to achieve a similar end goal as ours. For
example there exists a robot that elegantly mimics
human motion [IEE Link] also a BMW sponsored
project walks on multiple legs solely powered by wind
[Website Link]. However, in these devices and all other
similar research, the energy loss from transport is either
unknown or very high. Hence the findings and
outcomes from our research will help improve current
understanding and future application of walking robots.
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Expected Project Benefits:
1.
Problem Statement:
Currently the primary source of inefficiency in walking
robots is energy loss from the impact between the foot
and the ground which dramatically increases the cost of
transportation (COT). Our projects aims to demonstrate
an alternative walking motion that minimizes the energy
loss normally present in bipedal robot motion by means
of a Collisionless rimless wheel, which stores
mechanical energy between each collision, thus
minimizing COT, and extending the device’s range.
Objectives/Scope:
1.
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Four Spoke Collisionless rimless wheel
capable of "walking” across level ground (25
steps)
Minimal total energy use (<= .1 COT)
Wireless data acquisition for all trials (at least
3 meter range)
Timely Ability to control parameters while in
motion (Data sampling rate of at least 100Hz)
On board data storage (.1 hours)
Precise data set includes for both inertia and
rimless wheel:
o
Angular acceleration
o
Relative angular position between
inertial wheel and rimless wheel
Use of actuator power (electric motor) to
maintain movement
Easy and safe to use
Fully functional Collisionless rimless wheel
that meets the project objectives and
customer needs.
Documented set of experimental results for
50 repeated trials of 25 steps each.
MFG and Assembly documentation: how to
fabricate the prototype
Videos showing successful “walking” of 25
steps.
A <2min video explaining the project to the
general public
A video operation guide to running the device
and changing parameters.
Complete sets of raw data (time, angles, ang.
velocities) for all trials showing periodic
motion of state variables as well as total
electrical power use as a function of time for
a minimum of 25 steady state cycles.
Well-written operation/maintenance manual
(device operation, data collection, algorithm
modification, etc.)
2.
3.
Delivery of a fully functioning, four spoke
Collisionless rimless wheel, that is pre-loaded
manually and is then able to “walk”
independently without any assistance other
than its integrated electric motor.
Motor control settings can be modified on the
fly while system is in motion, thanks to
wireless data transmission.
Improve current understanding and future
application of walking robots
Core Team Members:
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Jeremy Benn (ME)
Jason Bowerman (EE)
Phil Buchling (ME)
Robert DeWitte (EE)
Madhur Jain (EE - Team Leader)
Senior Design Project Data Sheet
Strategy & Approach
Assumptions & Constraints:
1.
Assume all collisions with the ground are
completely inelastic.
2. Assume no slipping between feet of spokes
and ground for calculations.
3. Assume air resistance to be negligible for the
size of our device, and its relatively low
speed of travel.
4. Constrained by weight of device relative to
size. Excess weight of the structure will lead
to higher COT.
5. Constrained to minimum of 25 “steps” of
travel on level ground, in at least 50 trials.
6. Constrained by the need of additional
actuation (e.g. electric motor) to fulfill range
constraint.
7. Space constraint for mounting sensor and
control electronics. Ideally mounted around
axle hubs of wheel.
8. Constrained to wireless transmission of
sensor data and motor control data.
9. Constrained by budget. Overall cost cannot
exceed $900.00.
10. Can be inspired by previous unpowered
rimless wheel, but must build our own
hardware test bed.
11. Assume all electrical Electrical can perform
both individually and together as per
available specifications.
12. Assume initial condition is always met.
Issues & Risks:
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Designing a rigid structure that is able to
withstand the high stresses associated with
energy transfer through the torsion spring
and the electric motor. Maximum rigidity =
reduced energy losses in system due to
deformation.
Sizing and relative rotational inertias of the
inertial wheel and the spoke structure.
Implementation of power transmission from
batteries to various electronics and electric
motor.
Tolerancing and assembly of the two halves
of the spoke structure to ensure correct
assembly is possible.
Mounting electronic components on wheel
hubs such that weight is evenly distributed
and as close to the center of mass as
possible - i.e. Minimize rotational inertia of
rimless wheel.
Maximizing rotational inertia of inertial wheel:
Ballast weight at outer rim -> rim-mounted
batteries.
Interfacing all electrical components to
communicate with each other (Coding and
wiring)