Your knowledge of the inner workings of constructs allows you to gain control over them.
Benefit: Once per day, you may attempt to gain control of a construct. Upon a successful touch attack against the target construct, it must make a Will save (DC 10+ half your character level + your Charisma or Intelligence modifier) or else be under your control. A commanded construct is under your mental control and you must take a standard action to give it mental orders. You may only control a construct whose total Hit Dice do not exceed twice your character level. You may voluntarily relinquish command on a construct as a free action, at which point the construct resumes its former duties, and if possible resumes its former actions. If the construct’s true master is within line of sight of a construct you attempt to command or already have under your control, make an opposed Charisma check to determine who controls the construct permanently.