How are torpedoes controlled?

Answer 1

This depends on the type of torpedo, WWII torpedoes had An internal gyroscope which would be set before launch to a specific bearing. The rudder on the torpedo would turn until the desired heading was reached, then it would run straight until it either reached the end of its run or struck the target, these are commonly called straight run torpedoes because once they make the initial turn, the just go straight. Modern ADCAP torpedoes are much more complex and contain active and passive sonar sensors which will allow the torpedo to guide itself to a target.

Answer 2

Torpedoes are typically controlled remotely and autonomously. They are equipped with various sensors and guidance systems, such as sonar, to detect and track targets. The guidance system then calculates the desired trajectory and control surfaces, such as fins, are activated to steer the torpedo towards its target.