Simple introduction to Motion control (part 2)
From Wikipedia
Continued from the previous article: Simple introduction to Motion control (part 1).
The interface between the motion controller and drives it controls is very critical when coordinated motion is required, as it must provide tight synchronization.
Historically the only open interface was an analog signal, until open interfaces were developed that satisfied the requirements of coordinated motion control, the first being SERCOS in 1991 which is now enhanced to SERCOS III. Later interfaces capable of motion control include Profinet IRT, Ethernet Powerlink, and EtherCAT.
Common control functions include:
Velocity control.
Position (point-to-point) control: There are several methods for computing a motion trajectory. These are often based on the velocity profiles of a move such as a triangular profile, trapezoidal profile, or an S-curve profile.
Pressure or Force control.
Trans-mutational vector mapping.
Electronic gearing (or cam profiling): The position of a slave axis is mathematically linked to the position of a master axis. A good example of this would be in a system where two rotating drums turn at a given ratio to each other. A more advanced case of electronic gearing is electronic camming. With electronic camming, a slave axis follows a profile that is a function of the master position. This profile need not be salted, but it must be an animated function.
