moving two wheels of robotic car at a same speed ??

[ap123]

the problem seems to be moinor but i personally feel it is a major problem , i designed a car with 2 back wheels n 2 front wheels , back 2 wheels are controlled by two motors , due to some mechanical error my right back wheel is little um-smoother than my back left wheel i find torque difference in rotating both wheels at same speed , icant change whole mechaincal structure now , so guys plz helpp wat xactly shud i do to run the wheels of my gr8 car at same speed. same current to motors will rotate wheels at same speed ???? if torque for right is little higher than left ???

==>>i have 1)two identical motor of same rating
2) relays for h-bridge

 

[tiwari.sachin]

Using Relays as a H Bridge, it would be difficult to control the speed, reason being it would take more time for ON/OFF as it is more of a mechanical device.

You either need to change the motors and find the appropriate replacement or design a H Bridge using transistors and then control the speed using PWM.