grandparents rights to visitation

We have been very close to our grandchildren and now that my daughter is living with a partner which we can't get along with. he is kind of controlling over visting with our grandchildren. at this time he has 2 kids of his own which
his mother has custody and he is making it very difficult for us my husband and I to have visits with our grandchildren.
the oldest is a boy age 10 and up until recently he practically spent almost
every weekend with us ( we are legal guardians over another daughters son age 16 who is also very upset to loose contact with our grandson as they are very close he taught him how to ride a bike, play hockey, roller blade etc).
the other child is our granddaughter 10 months old this guy is playing daddy buthe really isn't the biological father. we got along with the fellow that my daughter is with but there was a problem where he left for about 2 or 3 months on a drug binge and during that time my daughter relyed on us for
support but since the guy returned he makes things very uncomfortable
for everyone involved. the grandson that we have living with us is vey upset as he got very close to both of these grandchildren. in 2005 our family went through a tough medical issue where my husband went through stomach surgery due to cancer and then went through chemo and radiation and when our granddaughter was born as sick as he was went to the hospital for the birth as we realized that this may be our last granchild. he is trying to let this
non visitation issue not bother him but it does and this is so close to christmas this is very difficult on everyone.
is there such a thing as us going to court and request visitation.

You can try yes--it is not always easy to get however and grandparents' rights vary somewhat state to state