Download Week 5

R2
R2
R2
GSCI 101
Two resistors in series
Two resistors in parallel
Two resistors in
with meters.
Two resistors in series
with meters
Monday reviewed some ideas about energy: KE, PE, Work
Discussed some general aspects of science [continuity and abstract concepts]
Wednesday One HW problems then practical circuits and wiring
One of the most basic circuits, a power supply, resistor and LED connected by wires.
PS power supply è ideal constant voltage supplied
wireè connections but unlimited current with no voltage drop
Resistorè Ohm’s law V=IR voltage pushes current through
Currentè FLOW charges move
R1
LEDè directional with a fixed voltage requirement [turn on voltage]
GNDè reference point in the circuit chosen to have a value of 0V.
R1
R1
R2
Power supply or a 5V connection with a GNDR2
connection.
On Arduino we can simple find pins labeled 5V and GND and use these.
Two resistors in parallel
Two resistors in series
Discussed paths, connections and proper orientation. Many students have trouble
building circuits. Not clear why at the beginning it may be hard but it is essential to learn
how to build a circuit from a diagram.
Robots
So far we have discussed, motion, forces and energy. An understanding of these
concepts is critical for robotics. As discussed real robot builders need an advanced
understanding of these ideas when designing robots from the ground up.
Robot
1. brain == microprocessor, computer
a. algorithms: to describe the processes
b. I/O: To sense environment and control motors and instruments
R2
Two resistors in
with meters
Other important areas for robotics are:
• digital electronics .i.e electronic logic
• analog signal processing
• binary systems
• programming language
• feedback
• pid
sensors (excerpted from PDF link on website, Howie Choset & Steve Stancliff)
Human Sensing
Sense: sight, hearing, taste, touch, smell
Vision
Audition
Gustation
Olfaction
Tactition
EM waves
Pressure waves
Chemicals -flavor
Chemicals -odor
Contact pressure
Othere senses heat, pain, balance, awareness?
animals
Magnetoception (birds)
Electroception (sharks, etc.)
Electroception (sharks, etc.)
Echolocation (bats, etc.)
Pressure gradient (fish)
Transduction
• What do all of these sensors have in common?
• They all transduce the measurand into some electrical property (voltage, current, resistance, capacitance,
inductance, etc.)
Motivationè control and environment knowledge
Lets imagine that we want to move a robot what is the most straightforward approach?
Wheels and a motor.
What does the motor do?
Rotates at some speed that turns the wheel.
How do we regulate the speed?
Gears & power to the motor. [car you can shift and you can press on the gas]
Hydraulic systems have same facility. Change force
Here is where the mechanics that we considered would be applied. Just like in the
problem with the pulleys [block and tackle] you can get different forces but not an overall
increase in the energy. Also the power or energy delivered per unit time will be
important.
Source è How much energy does it contain and how fast can it deliver it.
Most robots use electric motors and many sensors are electric.
Sensor to detect an obstacle è switch [try to be simple. If you don’t understand
whether a sensor is simple or complicated it shows that you need a clearer understanding!
Is it simple because you know where to get the stuff. Simple because you have seen it
work somewhere. Simple because the implementations requires only basic concepts and
components]
switch è basic
camera è complex but available and software is available but how do you detect
distance with a camera.?
ultrasonic ranger è available but complex in principle but the complexity may be
removed if you find the correct sensor that does all the work.
A sensor (also called detector) is a device that measures a physical
quantity and converts it into a signal which can be read by an observer or
by an instrument
typical
temperature
Position via on/off switch
Range - ultrasonic
motion
gps
gyroscopes
Voltage, power
force
pressure
vision
color
IR
conductance
acoustic
magnetic
Beacons/sensing
there not there
How far, speed, acceleration
Multiple methods
Location, speed, altitude grade
orientation
Monitor robots energy and delivery
Hydraulic systems
Multi faceted (facial rec., location, threat [cliff],
object id)
Imaging or point
Distinguish metal nonmetal
Volume, distinct sounds, voice recognition,
commands
Earths field as a reference
Send out a signal that is used for navigation or
other
other
radiation
chemical
weather
flow
electric
Humidity, wind, cloud cover (radar)
fluids
Capacitance, resistance, inductance, ….
Human beings have a multitude of senses. In addition to the traditionally
recognized five senses of
1. sight (ophthalmoception),
2. hearing (audioception),
3. taste (gustaoception),
4. smell (olfacoception or olfacception), and
5. touch (tactioception),
other senses include
1. temperature (thermoception),
2. kinesthetic sense (proprioception),
3. pain (nociception),
4. balance (equilibrioception) and
5. acceleration (kinesthesioception).
What constitutes a sense is a matter of some debate, leading to difficulties
in defining what exactly a sense is.
Sight
Sound
Taste
Humans receive tastes through sensory organs called taste buds, or
gustatory calyculi, concentrated on the upper surface of the tongue. The
sensation of taste can be categorized into five basic tastes: sweetness,
bitterness, sourness, saltiness, and umami. The recognition and
awareness of umami is a relatively recent development in Western
cuisine.[3] MSG produces a strong umami taste.[4]
[edit]
Smell
Smell or olfaction is the other "chemical" sense. Unlike taste, there are
hundreds of olfactory receptors (388 according to one source[4]), each
binding to a particular molecular feature. Odor molecules possess a variety
of features and, thus, excite specific receptors more or less strongly. This
combination of excitatory signals from different receptors makes up what
we perceive as the molecule's smell. In the brain, olfaction is processed by
the olfactory system. Olfactory receptor neurons in the nose differ from
most other neurons in that they die and regenerate on a regular basis. The
inability to smell is called anosmia. Some neurons in the nose are
specialized to detect pheromones.[citation needed]
[edit]
Touch
Touch, also called tactition or mechanoreception, is a perception
resulting from activation of neural receptors, generally in the skin including
hair follicles, but also in the tongue, throat, and mucosa. A variety of
pressure receptors respond to variations in pressure (firm, brushing,
sustained, etc.). The touch sense of itching caused by insect bites or
allergies involves special itch-specific neurons in the skin and spinal
cord.[5] The loss or impairment of the ability to feel anything touched is
called tactile anesthesia. Paresthesia is a sensation of tingling, pricking, or
numbness of the skin that may result from nerve damage and may be
permanent or temporary.
[edit]
Balance and acceleration
Main article: Vestibular system
Balance, equilibrioception, or vestibular sense is the sense that allows
an organism to sense body movement, direction, and acceleration, and to
attain and maintain postural equilibrium and balance. The organ of
equilibrioception is the vestibular labyrinthine system found in both of the
inner ears. In technical terms, this organ is responsible for two senses of
angular momentum acceleration and linear acceleration (which also
senses gravity), but they are known together as equilibrioception.
The vestibular nerve conducts information from sensory receptors in three
ampulla that sense motion of fluid in three semicircular canals caused by
three-dimensional rotation of the head. The vestibular nerve also conducts
information from the utricle and the saccule, which contain hair-like
sensory receptors that bend under the weight of otoliths (which are small
crystals of calcium carbonate) that provide the inertia needed to detect
head rotation, linear acceleration, and the direction of gravitational force.
[edit]
Temperature
Thermoception is the sense of heat and the absence of heat (cold) by
the skin and including internal skin passages, or, rather, the heat flux (the
rate of heat flow) in these areas. There are specialized receptors for cold
(declining temperature) and to heat. The cold receptors play an important
part in the dog's sense of smell, telling wind direction. The heat receptors
are sensitive to infrared radiation and can occur in specialized organs for
instance in pit vipers. The thermoceptors in the skin are quite different from
the homeostatic thermoceptors in the brain (hypothalamus), which provide
feedback on internal body temperature.
Mammals have at least two types of sensor: those that detect heat (i.e.
temperatures above body temperature) and those that detect cold (i.e.
temperatures below body temperature).[
[edit]
Kinesthetic sense
Proprioception, the kinesthetic sense, provides the parietal cortex of the
brain with information on the relative positions of the parts of the body.
Neurologists test this sense by telling patients to close their eyes and touch
their own nose with the tip of a finger. Assuming proper proprioceptive
function, at no time will the person lose awareness of where the hand
actually is, even though it is not being detected by any of the other senses.
Proprioception and touch are related in subtle ways, and their impairment
results in surprising and deep deficits in perception and action.[6]
[edit]
Pain
Nociception (physiological pain) signals nerve-damage or damage to
tissue. The three types of pain receptors are cutaneous (skin), somatic
(joints and bones), and visceral (body organs). It was previously believed
that pain was simply the overloading of pressure receptors, but research in
the first half of the 20th century indicated that pain is a distinct
phenomenon that intertwines with all of the other senses, including touch.
Pain was once considered an entirely subjective experience, but recent
studies show that pain is registered in the anterior cingulate gyrus of the
brain.[7] The main function of pain is to warn us about dangers. For
example, humans avoid touching a sharp needle or hot object or extending
an arm beyond a safe limit because it hurts, and thus is dangerous.
Without pain, people could do many dangerous things without realizing it.
An internal sense or interoception is "any sense that is normally
stimulated from within the body".[8] These involve numerous sensory
receptors in internal organs, such as stretch receptors that are
neurologically linked to the brain.
Pulmonary stretch receptors are found in the lungs and control the
respiratory rate.
The chemoreceptor trigger zone is an area of the medulla in the brain
that receives inputs from blood-borne drugs or hormones, and
communicates with the vomiting center.
Cutaneous receptors in the skin not only respond to touch, pressure, and
temperature, but also respond to vasodilation in the skin such as
blushing.
Stretch receptors in the gastrointestinal tract sense gas distension that
may result in colic pain.
Stimulation of sensory receptors in the esophagus result in sensations
felt in the throat when swallowing, vomiting, or during acid reflux.
Sensory receptors in pharynx mucosa, similar to touch receptors in the
skin, sense foreign objects such as food that may result in a gag
reflex and corresponding gagging sensation.
Stimulation of sensory receptors in the urinary bladder and rectum may
result in sensations of fullness.
Stimulation of stretch sensors that sense dilation of various blood vessels
may result in pain, for example headache caused by vasodilation of brain
arteries.