Most PTZ currently uses the worm gear structure.
Advantages:
1. Low price
2. Self-locking
3. Fast delivery time (In stock)
Disadvantages:
1. Low accuracy, and easy to wear
2. Large size
If replace the above scheme with harmonic reducer.
Advantages:
1. High accuracy
2. Small size
Future trend:
There are many applications of PTZ, and the market is very large. It could be used for surveillance, inspection, photography and other occasions.