Welcome to the ODK forum, @zhangcal! We're glad you're here. When you get a chance, please introduce yourself on this forum thread.
ODK Aggregate and Central can both be installed on your own server. They don't have to be installed with a cloud services provider. If you're using OpenMapKit and collecting OSM data, you'll need to use OpenMapKitServer, as I don't think Aggregate and Central are configured to accept OSM data. HOT OSM maintains a fork that is more up-to-date than the POSM repository. The development installation instructions might be helpful for figuring out setup on your own server.
If you're collecting geographic data or OSM data, there's a discussion about improving these features in ODK that you might be interested in joining: Selecting a map feature to collect data about