There are several old threads about the problem of parking outside of paid parking lots in Lausanne. I just found out some valuable (to me anyway) info on how it works. Please pardon my incorrect french spelling and other descriptive mistakes.
1. In "Sauf Autorization" areas you can park for one hour using the blue arrival time indicators (sorry don't know of hand what these are called). At 19:00 you can set it and then in an hour reset it to 8:00am. That gives you overnight parking but you must move your car before 9:00am. This works Mon-Sat. Saturday you can leave it until Monday morning.
2. If you are visiting for more than a day you can go to the "Hotel du Police" and get scratch cards (for a daily fee) that will cover 24 hours. It is currently 15CHF for non-city-center parking (Cartes périphérie du centre). The catch is that you have to go there with the resident you are staying with. Perhaps some hotels already have these.
It is detailed here in French http://www.lausanne.ch/en/lausanne-o...s-parcage.html