I'm looking for NLP techniques to transform sentences without affecting their meaning, and measures of textual consistency. For example, techniques that could transform active voice into passive voice, such as
The cat was chasing the mouse.
The mouse was being chased by the cat.
I can think of a number of heuristics one could implement to make this happen for specific cases, but would assume that there is existing research on this in the field of linguistics or NLP. My searches for "sentence transformation" and similar terms didn't bring up anything though, and I'm wondering if I simply have the wrong search terms.
Related to this, I'm also looking for measures of text consistency, e.g., an approach that could detect that most sentences in a corpus are written in active voice and detect outliers written in passive voice. I'm using active vs. passive voice as an example here and would be interested in more general approaches. Any pointers would be much appreciated, thanks!