You have learned this week about gait generation, about creating and executing all the gaits for the exoskeleton. But how is gait generation conducted at Project MARCH? We will not only tell you about it in this part, but we will also show you how we work.

In previous years Project MARCH had aside from Software Engineers and Control Engineers, also Movement Engineers. Their main function was to design all the gaits for the exoskeleton. They worked in a custom built application, called the Gait Generator, and designed a trajectory for each joint and each gait they made. Currently, we have split up the function of the Movement Engineers into a Human Department. They mainly focus on the interaction between the exoskeleton and the pilot. The department enholds a Motion Planner Engineer, a Human Machine Interaction Engineer, and a Human Engineer. The Motion Planner creates gaits for different situations like walking, sitting, climbing stairs, ascending, and descending a slope. The Human Machine Interaction Engineer is trying to make the exoskeleton brain controlled. And the Human Engineer makes sure that the preferences of the pilot are applied in the exoskeleton and that medical aspects are taken into account.

Once the gaits look right in the simulation, we start testing them. The first thing we do is something called airgaiting. This means we hang the exoskeleton in a specially made stand and perform the gait in the air. This is an easy and safe way to see if the exoskeleton can follow the gait: is it doing exactly what we want?

When it does, we go to the next step, which is aptly called groundgaiting. You already saw this at the end of week two: a coach holds the exoskeleton and we walk with it, without the pilot. This way, we can see if the steps are big enough to walk up the next step of the stairs, if the step is high enough to step over an obstacle, or if we sit down at the right height.

Only after we are sure the gait is safe and correct, we start testing it with the pilot. Sometimes the gait turns out a little different when the pilot performs it, because – as you already have heard often in this course – the pilot has quite a large influence on the exoskeleton. And he or she often has feedback as well. So gait generation is a continuous process: we constantly go back a couple of steps, adjust the gait and then go through the whole process of testing again. We repeat this until we are confident we have made the perfect gait. Wonder what this process looked like for us? Take a look at the video below!

In previous years the goal was to make gaits for each obstacle of the Cybathlon, the competition in which teams from all over the world participate. The Cybathlon has six obstacles: sitting down and standing up again, a slalom, stepping over several obstacles on the floor, ascending and descending a flight of stairs, walking over a tilted surface, and ascending and descending a ramp. During this competition, we want to overcome all of these obstacles – and that is quite a task for someone in an exoskeleton! Moreover, we want to do this as fast as possible. So we decide on the best race strategy and sometimes make several different options for gaits, so we can decide on the strategy together with the pilot. Do you want to know what the Cybathlon looks like and how we performed at the Cybathlon Experience in Düsseldorf in 2018? Watch the video below!

Unfortunately, the Cybathlon did not continue due to COVID-19. Therefore, new goals were set. And this was a great success, last year we walked outside for the first time!

(The video itself is in Dutch, but make sure to turn on subtitles for a translation in English!)