Humans have wondered what is on Mars for centuries, and we still haven't gotten the chance to go there ourselves yet. Instead, we have to settle for the next best thing: robots. The Perseverance rover is the latest exploration robot in a long lineage of other machines dating back to the 1990s, and it is quite amazing. The robot packs a whole suite of onboard sensors, cameras, a mobile science laboratory, and is powered by a nuclear energy source, so it's understandable that someone wanted to make it into a model. Dejan explains in his article how he did just that, but it not only looks amazing, it also moves and has its own camera system to emulate the real one.
Dejan began this project by fully modelling his rover design in Solidworks with incredible levels of detail. It includes the six individually-steerable wheels that each have their own motor. The camera housing is perched on top of a mast that can rotate, and the back of the vehicle has the mock radioisotope power system. Perhaps the best part of this design is that it's fully scaled-down replica.
In order to go from a virtual CAD model to an actual driving robot, Dejan collected all of the necessary parts, and there are a lot of them. The main structure is provided by several aluminum extrusions that are fastened together with T-slot corner brackets. Once the frame was done, the decorative 3D-printed panels went on next, followed by the electronics.
As one might expect from a rover of this size and complexity, there are quite a few electronic components needed to make this work. As previously stated, each wheel is independently driven by a 12V 37mm DC motor and DRV8871 DC motor driver. The four outer wheels are able to turn, so a servo is mounted above each to pivot the wheel. The camera is controlled horizontally by a stepper motor that's driven by an A4988 module, and tilt is provided by a servo motor. Finally, a 3S LiPo battery powers the entire rover via a buck converter, and everything is controlled with an RC transmitter/receiver and an Arduino Mega 2560.
One really interesting part of this rover is its ability to slowly-but-surely crawl over rough terrain — just like the actual Perseverance rover. And because it has an FPV racing camera, the driver can wear a set of VR goggles or just use their phone to view footage coming from the camera mast in real-time.