Curiosity

Background

When I was learning the possibilities of a 360-degree video camera, I wanted to test attaching the camera to different kinds of moving vehicles. So, I put the camera to car rooftop, a snowmobile bumper, a bicycle, a harvester machine, etc.

360-degree cameras work well also with small scale objects, such as RC toy cars. I got the idea that it might be fun to have a remote-controlled vehicle with a live 360-video stream to a VR headset, giving the feeling of being “inside” the vehicle while driving it.

I made some experiments with vehicles that I built from Lego Technic bricks. The actual Mars rover Curiosity was not really a model for this moving robot, but the result does have some resemblance, and so the name stick with it.

Building

The robot has a motorized 6-wheel drive, powered by two Mindstorm series motors and the control unit. It is driven similar to a tank: each side (3 wheels per side) can be separately run forward or backward, and driving them to opposite directions makes the vehicle to turn on the spot.

To minimize friction when turning, I had to add tape to the front and back tires. You can easily see why from the video below. Other than the tapes, the model is a pure Lego build.

There’s also a marble cannon from the Mindstorm set, just because it was so easy and fun to attach it to this vehicle. No real purpose, though.

In this video, I am testing my Curiosity robot in the living room. Kids are worried, they think the robot is just making a mess! It is kind of wobbly, the bodywork is heavy. I had to add more supports later. Nevertheless, maneuvering on the wooden floor and the carpet seems to work quite alright. The cannon works, too.

360-degree view

I spent quite some time designing the suspension system for the wheels. I wanted to get traction with all 6 wheels on an uneven surface so that the rover would not get stuck too easily. It worked pretty well in the end. To observe it in action, I put a Ricoh Theta S camera under the hood and filmed a couple of short clips outdoors, driving it on the kid’s playground sand.

These are 360-degree videos. Use touch/mouse/WASD keys to turn around, there’s more to see!

Curiosity is crawling nicely on the lawn and on the sand:

Postscript

I took the robot to work one day, put a 360-degree camera on it, and live-streamed the video to a VR headset. The concept was nice, but at that time the technology was not mature enough to make it as fun as I imagined. The resolution and latency were too far from what is needed to actually drive the robot remotely.

I will probably re-visit the topic later when the cameras are 1-2 generations further. The next build could be a combination of RC car parts and 3D-printed parts, this way I could get more power and lighter bodywork. Lego bricks are heavy for this kind of larger models.