Slow dow or speed up objects between two points

Hi Guys

I have an object bouncing between two target objects (similar to lerpz 2d platform) with some speed. How can I possibly change that speed of the object to make it look smooth acceleration when increase speed value and if I turn down the speed it would slow down smoothly and not jumping between positions? Thanks Joseph

First one is the actual thing, second one is a visual editor...

Play around with that, and you can easily do what you want... Just a suggestion =).