Hardware

This week was mostly spent waiting for the raspberry pi to finish various tasks such as installing dependencies and building software. We were not able to do much progress on the programming because when the pi is working we cannot do anything else on it. And the building process usually takes hours. The long work times were amplified by errors in the building process which itself took hours before they were detected

We are also looking into getting a Kinect and wireless sender. In addition, we burrowed a raspberry pi 3 B+ to increase our horsepower on board. 

Here is a diagram showing the rough wiring of our system so far.

3D-Mapping

We tried to install Ros-Indigo on our raspberry pi 1 and it seemed to work well except for one problem at the end of the build order, we believe that this is because of the limited memory on the raspberry pi 1 and have therefore decided to switch to a raspberry pi 3 B+

This last week we have been working on getting ROS to work on both the Raspberry Pi and the computers. Regarding the computer progress, we managed to get the RTAB-map program to process a database of stereo images into 3D map, we were not able to produce images ourselves because of lack of hardware capable of recording in stereo, this means that we lacked a device with two synchronized cameras that we could use with the program. This meant that we needed to find something that could handle the task, we found some cheap Microsoft Kinect online that we could use. 

If we manage to get a proper input device, we could be on our way to get the 3d mapping completed on a handheld device which we could later use to integrate it unto our drone. Once we get our stereo camera we can start learning how the outputs of the camera can be used in our program, after a lot of reading on how RTAB-map works together with ROS we have somewhat of an idea how to proceed.

More about arm/gripper 

This week we had some fun playing with lego Mindstorms and we made some physical models out of our sketches from last week. This is the first time we played with lego Mindstorms which made this process a bit slower. However, we managed to make a physical model that might work with some adjustments. We have also purchased an unassembled gripper from a website called Banggood (https://www.banggood.com/) as a plan B. 

This is the physical model that we build with Lego Mindstorms. We use 4 gears and a step motor connected to one of the gear to make all the gears rotate. We try to demonstrate how our gripper might grab some object on the left top corner. We will work further with this model and try to improve it while we are waiting for our purchased model. But as said before that will be our plan B if plan A doesn’t go as expected.