Need help Automating DC Motors

I have been working on a project , its basically a six wheeled unmanned vehicle that i can control through a BT device. So how i need it to work is i define a path to the arduino and i want the arduino to save it and when i send repeat signal i want it to repeat the same exact motion again . Its easy to do this if the whole setup involves only servo but is there any possible way i can automate DC motors ? since it doesnt have the capability to get the position i coded the arduino to register the total time run per each motor and tried to repeat it , i think its getting registered but its not executing . So i need help over this issue . Please let me know if i can actually automate the dc motor ( and i am using 12V DC motors High torque and High rpm and using a relay circuit to drive the motors as i am using 6 dc motors i didnt get a proper driver module ) Please share if you have any solutions . Thank you

Without the ability of your robot to verify its position using an external reference (such as a line on the floor) it will be difficult to the point of impossible to get it to repeat a series of movements. Every small variation in the speed of one or other of the motors and every small slippage between the wheels and the floor will accumulate to produce significant errors. Even going in a straight line there is potential for slippage and it is inevitable and unavoidable when the machine turns.

...R

Is there any possible solutions you can suggest ?

prdk7:
Is there any possible solutions you can suggest ?

Not without more information from you about the environment in which your robot is intended to operate.

Also, why will it be necessary to repeat its path?

At the moment you have given us very little information about what you are trying to create.

...R

You need to close the loop using encoders. They you have a reasonable good measurement of wheel rotation
both to determine trajectory taken and control following a commanded trajectory.

Its basically a material handling system , i need to transfer some stuff over long distances so i pick up stuff from point A drop it at B , and i take it back to point A . Then i want it to put it on repeat mode

prdk7:
Its basically a material handling system , i need to transfer some stuff over long distances so i pick up stuff from point A drop it at B , and i take it back to point A . Then i want it to put it on repeat mode

You are a man of few words.

A longer explanation would be a good thing. What sort of material, what distances, what terrain does it need to traverse ... and everything else that you know about YOUR project and we don't know.

...R

prdk7:
Its basically a material handling system , i need to transfer some stuff over long distances so i pick up stuff from point A drop it at B , and i take it back to point A . Then i want it to put it on repeat mode

Over long distances outside - needs GPS.

Inside - more problematical, various ways are possible.