This week Walid worked on developing a new collection Acumen examples
to illustrate some of the basic concepts of control. These new
examples, tentatively named HelloControl.acm, are written to make more
use of Acumen objects and of 3D visualization. Objects can help users
build physically reasonable models by encouraging them to think about
boundaries between different entities and about what is or is not
readily available to one object from another. Adding 3D visualization
seems fairly natural once we are already using objects. One example
is intended to facilitate discussing proportional/differential (or
dampening) control. The system being controlled consists of three
masses connected by two springs (along a line), and the control force
is applied to the outer two masses. Behind each system is a green bar representing the total energy (kinetic+potential) in the system. The goal is to stabilize the
system at a length where the system is at rest. Here is the 3D output
from an example with three different parameter values for the PD
controller.
Another example is aimed at explaining proportional/integral/differential (PID) control. In this instance there is a single mass, but it is a three dimensional entity subject to gravity and a small, periodic disturbance. A small ball marks the goal position for each system. Again, multiple different parameter values are compared.
In the class room setting we presented each example along with its Acumen code, and carefully explain and discuss each example system in each video in detail. When writing formally, it is important to make sure that any video or figure (such as the ones above) are explained in detail in the text that mentions them. For the present short communication, though, you are instead invited to conjecture on which parameters are varied between the different systems to achieve the effects seen above.
Another example is aimed at explaining proportional/integral/differential (PID) control. In this instance there is a single mass, but it is a three dimensional entity subject to gravity and a small, periodic disturbance. A small ball marks the goal position for each system. Again, multiple different parameter values are compared.
In the class room setting we presented each example along with its Acumen code, and carefully explain and discuss each example system in each video in detail. When writing formally, it is important to make sure that any video or figure (such as the ones above) are explained in detail in the text that mentions them. For the present short communication, though, you are instead invited to conjecture on which parameters are varied between the different systems to achieve the effects seen above.
