Splitting concave polygons into convex polygons in QGIS

I want to optimize and decompose several concave polygon into convex ones but not too small or to complicated ones.Ideally cutting in places that would minimize the creation of convex polygons and in a way they are more close to being regular.
(I have selected some of theme just to be more clear)

I have tried (and they don’t work):

• Triangulation – Creating a lot of small polygons with Delaunay or other methods creates a lot of small polygons and it doesn’t help me in my final objective.
  

• Convex-hull – It changes the shape of my polygons and I don’t want to change that because they contain information.
  

I need this because each of these polygons have information that I’m going to keep in points in a mesh to make thermic calculations after. I want to create this elementary polygons to then take the centroid of each one of them and create this mesh. So because of that it would be bizarre taking a centroid out of the polygon or taking the pole of inaccessibility and having a polygon that its almost "twisted".

An output for this selected polygons would be to cut them in concave pieces and then when we take their centroids would be something like these: