CONTROL OF HUMAN MOVEMENT Flashcards
How many neurones are present in the brain
100 billion
How much % of total energy does the brain consume
20% of total energy
Why doesn’t the brain feel pain
It has no nerves
Therefore feels no pain
What type of relationship do curvature and velocity have
positive relationship
what is space
a set of points with some added structures
What does Fitts Law state
If you need accuracy you become slower
What are coordinates
A set of numbers that uniquely determine a point in space
Can one space have multiple coordinate systems
Yes
What can a coordinate frame also be called
A reference frame
Define egocentric
coordinate system attached to our body
Define allocentric
coordinate system attached to external world/ object
If you are trying to find kinetics is it inverse of forward dynamics
Inverse
you are trying to find kinetics so you go from
kinematics –> kinetics which is inverse
If you are trying to find kinematics it inverse of forward dynamics
Forward
you are trying to find kinematics so you go from
kinetics –> kinematics which is forward
What does kinetics refer to
forces & torques
What does kinematics refer to
distances & angles
What is newtons 2nd law
F=ma
What is feedforward control
You plan in advance
Pre determined actions
What type of loop is feedforward control
open loop
what are the pros of feedforward control/ open loop
Movement can be controlled without gathering/ processing any external info
good for fast movement
what are the cons of feedforward control/ open loop
Error made by controller accumulates over time
No flexibility to environmental changes
High cost of planning, no generalisation
what is feedback control
You have policies (rule/ strategy), controller is gathering/ processing sensory feedback
eg- tube tourist example: ask around then go there, then ask again
what type of loop is feedback control
closed
what are the pros of feedback control/ closed loop
Flexible- can deal with unexpected events
Robust- control error does not accumulate over time
General- control is invariant to starting or goal opposition
what are the cons of feedback control/ closed loop
Processing sensory feedbacks is time consuming- not good for fast movement
Controller can become unstable when sensory feedbacks are noisy and the feedback gain is high (how seriously one takes the answer)
Can also become unstable when feedbacks are delayed