Antonym of ERRATIC

Erratic : not even or regular in pattern or movement; unpredictable.
Regular : arranged in or constituting a constant or definite pattern, especially with the same space between individual instances.
Right : morally good, justified, or acceptable.
Punctual : happening or doing something at the agreed or proper time.
Free : able to act or be done as one wishes; not under the control of another.

Antonym of Erratic is Regular