Direct torque control (DTC) is a method used in variable-frequency drives to regulate the torque (and hence, eventually, the speed) of motors such as BLDC, PMSM, induction motors, and so on. This involves estimating the motor's torque and magnetic flux based on the motor's recorded current and voltage.
Field-Oriented Control (FOC), also known as vector control, is an approach for dealing with AC Induction Motors (ACIM) and Permanent Magnet Synchronous Motors (PMSM). Field-Oriented Control (FOC) provides effective management of maximum torque and speed ranges.