Do you have a pop up canopy that looks like this? I have about six in various stages of collapse. They just do not stand up to wind. I am not sure about my design but, we had 60 plus mph winds and it was still standing the next day. This is a good permanent structure. Measure the old frame and make a 2x3 frame of the same dimension. Cut two rafters and install in the center as shown below. Then cut the rafters for the other two sides. Cutting the other four rafters with compound 45 degree cuts is a little trickier. Use some scrap to test your cut and angles first. The angles will depend upon the size and brand of canopy you are repairing. I will try to get a video made to show you how to calculate these but, sorry for now you are on your own.

Next set the corner post in. I suggest treated lumber for the corner post. Cross brace the post on both sides. Then cross brace the corners to keep the frame square. When finished sand or rasp all the edges so they do not rub a hole in the canvas. If you set it on the dirt put a plate under the legs to keep them from settling in the ground. also steak or tie down the legs so that your canopy does not blow away. The photo below shows how I keep mine from blowing away.