Tag: Mimas Rover

The camera housing of Imager's first version (last update 08/09/2022) was completely renewed by substituting all components with 3D printed parts. The structure is now pivoted on an "L" shaped piece and tilt rotation is done using a servo motor. This choice was made to ensure a precise movement using angles or radiants, instead of steps. Since the camera housing is not heavy, there is no need to use a stepper motor, so a high-torque servo motor has been implemented.

• [Hours of work: 1h]
• [People involved: Giorgio]

The first component of Mimas that will be used in the actual final assembly has been 3D printed at Edinburgh Napier Merchiston Campus, thanks to Alexandros Gkanatsios' help. The part needs to be sanded and white-painted. However, this represents the first great step towards the final assembly of Mimas Rover!

• [Hours of work: -]
• [People involved: Giorgio, Akshit]

After several attempts, a stepper motor flange was installed on the structure, since previously the camera housing was attached to the motor only using a custom/adapted nut screwed tightly. The new flange ensures structural rigidity and increases rotation precision. The code accuracy has been increased, as well as the algorithm used to process panoramic pictures. The main improvement concerns a post-process step to remove the lens distortion when taking a panoramic picture: even if the results obtained are good, there is still a lot of room for further improvements. The two images below show the differences between a non-processed panoramic picture (top) and a processed panoramic picture (bottom): the second one lost some details around the frame of the image, mainly on the upper and lower part.

• [Hours of work: 15h]
• [People involved: Giorgio]

The team discussed some functionalities of Mimas Rover, such as the robotic arm and the sample-catching system. Adding a range of tools to collect different samples from the terrain, such as sand, soil and rocks, may allow the rover to be more useful for scientific experiments in a real-world situation, so they were considered when the discussion was taking place.

• [Hours of work: 3h]
• [People involved: Giorgio, Akshit]

The Imager has been renewed, slightly changing its structure and the Micro Servo was substituted with a small stepper motor. Cable management has been carried out and the first panoramic picture taken since the arrival to Edinburgh was successfully taken!

• [Hours of work: 6h]
• [People involved: Giorgio]

Reassembly of all components after the trip required a few hours and for the first time, the Imager was assembled on top of the Rover Equipment Deck, which is the upper part of the WEB, where all sensors and the mast can be placed. A Micro Servo SG90 has been connected between the camera housing and the mast tower, to ensure precise pitch rotation control. However, due to the absence of a metal flange, the overall structure is wobbly and needs several improvements.

• [Hours of work: 5h]
• [People involved: Giorgio]

Due to the end of the summer break, all components assembled in the past 2 months were disassembled and gently packed, ready for a long journey by car from Milan (Italy) to Edinburgh. The overall list of innovations made for the Honours Project during the summer includes computer vision colour detection, computer vision free-path recognition, computer vision image stitching, a draft of the mast with its rotation mechanism, the WEB frame, six all-stainless-steel wheels, and a fully configured Raspberry Pi4. In addition, several additional components were packed for the trip: four high-torque servo motors, six high-torque DC motors, hundreds of connectors, jump wires, sensors, battery packs, motor drivers, nuts and bolts and many other equipment tools and consumables, for a total weight of ~50kg.

• [Hours of work: 1h]
• [People involved: Giorgio]

The Warm Electronics Box (WEB) is the main body of the rover, it carries and protects the computer, the electronics and the instrument systems (which are basically the equivalent of the rover's brains and heart). This structure needs to be extremely solid and as spacious as possible. For Mimas, the WEB was assembled using several stainless steel bars, kept together by nuts and bolts. The obtained shape is a metal frame that will certainly undergo several upgrades and changes: white panels will be assembled to protect the delicate components inside it and the upper part will host the Rover Equipment Deck.

• [Hours of work: 4h]
• [People involved: Giorgio]

Commonly referred to as the "Imager", the mast is a tower-shaped component that elevates key camera systems and sensors, giving the rover a human-scale perspective on its environment. The first version of its structure was assembled, however, the design is not stable and the rotation mechanisms for the pan and tilt are not working smoothly. A webcam is positioned on top to start experimenting with OpenCV for photo capturing and image stitching.

• [Hours of work: 12h]
• [People involved: Giorgio]