I need to occasionally restart my router to fix my internet coection. Can I detect it with a script and restart automatically?

I am using buffalo router WZR-HP-G300NH with DD-wrt firmware. The inteet sometimes slow down and devices caot even join the the WIFI. If I reboot the router, everything is back to normal. This can happen several times a day. Is there any script to detect the the problem in the router and restart automatically?