A few things come to mind- not exactly peer reviewed journals, but there may be some more out there or in development...
1. Donn Griffiths presented his dissertation a few years ago at the FIRST Robotics Conference. I don't know if he has submitted it for publication. (Nudge!)
2. MOE mentors wrote a chapter, "Educational Robotics" in Ken Tobin's
Teaching and Learning Science: A Handbook (2006)
SEE THREAD. (Shameless plug!)
3. Recently mentors & students from Dawgma FRC1712 published an article in ITEA's
Technology Teacher "Portable Inspiration: The Necessity of STEM Outreach Investment," which explained their outreach project which uses vex robots-
SEE THREAD. (Awesome squared!)
BTW- Nice paper- Was it for a conference presentation? How should/could it be cited?