Jason K. Moore

EME 1 Lecture

November 28, 2016

Sam Whittingham, world record (~80 mph)

- Why is one bicycle harder to control than another?
- How can we design a bicycle such that it is easy to control?

Bicycles are curious machines

- Bicycles are the most efficient from of human transportation (lowest energy per person per distance)

- In general, you have to balance a bicycle before directing it from point A to B

- It is possible to balance a bicycle without touching the handlebars

- People can do all kinds of stunts on bicycles

If you want you bicycle to turn to the left, what direction do you turn the handlebars?

If you are in a steady right hand turn, you must be leaning to the right. So, the only way to initiate a right hand lean is to move the wheel contact points out to the left.

Think about balancing a broom.

Also predicted by Newton's Laws!

$F = m a$

Most bicycles are stable once they reach a certain speed, i.e. if you try to knock it over it rights itself.

"The wheel is a gyroscope so it always steers in the correct direction"

"The front wheel of a bicycle trails behind the steering axis just like a caster on an office chair, so the wheel always corrects the steering."

TU Delft Two Mass Skate Bicycle

- We sense our body position, orientation, and configuration with our eyes
- We sense our body's configuration with muscle spindles
- We sense our orientation wrt to gravity, orientation rate, and angular acceleration with the utricle in our ear
- We sense forces being applied to our body with our proceptive system

- Time delays from sensing to acutation
- Limits in acutation forces
- Limits in frequency of motion

Feedforward and feedback mathematical models can predict the human sensing and actuation relationship.

- The
**dynamics**of the bicycle describe how it moves when forces are applied to it. - Humans apply forces to a bicycle to make it transport them where they want to go.
- The dynamics can be changed by changing the vehicles
**physical properties**, i.e. mass, geometry, tires, etc.

This leads to my research interests:

How do we design human controlled machines (e.g. vehicles) such that they perfectly compliment the human's intentions?

- Create mathematical models that predict how machines move if forces are applied to them.

Design can be treated as an optimization.

Once you have mathematical definitions of a system you can then use mathematical and computational techniques to answer questions like:

"What would the geometry of the vehicle be if it was the easiest to control?"

F-22 Raptor

BMW's Concept

- My website: http://www.moorepants.info
- My dissertation: http://moorepants.github.io/dissertation/
- Papers: http://tinyurl.com/jkm-gscholar
- Twitter, G+, Linkedin, etc: moorepants
- My office: Bainer 2095
- My email: jkm@ucdavis.edu
- Classes I currently teach: EME 150A, EME 185A/B, ENG 122