Resulting motion (thicker solid line, right y-axis) from (a) LLCM-WIP [2], (b) GUD WIP, and (c) Real Walking. In this example, the two WIP systems are driven by the same in-place steps (dashed line, left y-axis). The Real-Walking motion is caused by steps taken at approximately the same frequencies as the in-place steps for the WIP systems. Note LLCM-WIP’s resulting speed varies considerably. GUD WIP’s resulting speed is far steady – similar to Real Walking.