CRJ-700 Captain reported a malfunction with nose wheel steering during takeoff roll.

Narrative

Start up and taxi was normal to Runway XXR. Once cleared for takeoff we taxied onto Runway XXR and began adding power. While maintaining centerline control with the rudder pedals; I noticed the control input seemed to be off as the nose drifted from centerline to the left at a speed of approximately 5-10 kts. At the time I assumed I may have hit a small hump in the pavement which effected the steering momentarily. After correcting for this deviation with the tiller; I added power to about halfway to TOGA (Takeoff Go-Around). Again; directional control with the rudder pedals felt incorrect as we drifted to the right of centerline this time. I added left rudder and the drifting to the right of centerline actually got worse. I then rejected takeoff; bringing the thrust levers to idle and called 'reject'. Maximum airspeed achieved was approximately 30 kts. The FO (First Officer) and I complied with all SOP's regarding a rejected takeoff. The FO informed Tower of the situation and we exited Runway XXR at Taxiway Q. Nosewheel steering with the tiller; and differential braking still worked perfectly fine.Once off the runway we developed and analyzed a plan along with the maintenance director on our jumpseat. We all agreed to head back to the hangar to have the situation checked out. We taxied to the hangar without issue. In the end; Maintenance discovered the rudder input command module was malfunctioning.The only way in our position to have discovered that this was malfunctioning was unfortunately when we did; on the runway maintaining directional control with the rudder pedals. In the future; a closer check by the Maintenance team after heavy maintenance could prevent a similar situation.Rudder command module which actuates nose-wheel steering malfunctioning.