Robot Task

23/8/18 Today, Max and Nathan continued the construction of the new design for the robot. They added double wheels to the outside of the motors, and these were mounted to the front of the robot at an angle facing forwards, with the motors protruding in front of the robot itself. We noticed that the robot sagged outwards, so we added a support beam spanning between the two motors. This took some trial and error, but we mounted the shaft and also added some cogs to the design for cosmetic good measure. The back wheels were taken from the pervious NXT design, and modified slightly to better attach to the back of the NXT brick. The end result of today's lesson was a very capable and flexible base design, in the way that it can be modified and adjusted easily to suit almost any task and terrain.

30/8/18 Today we experimented with the light brick. The light brick is a small lego piece capable of producing light through a small incandescent globe. We experimented with the use of this on our robot, and the programming of this as part of our robot. After Max built a mount for the light brick, we decided to program it. This was more difficult and time consuming than we had hoped, however it did eventually operate, following a few failed attempts at coding the little light. The experience gained by coding the light was of benefit however, with all of us gaining a better understanding of how the NXT coding operated, and how it responded to certain changes and interactions. We decided the test the light brick and our new design, by making a simple program capable of demonstrating the light brick and the operation of our robot. This failed dismally, however. The robot ran backwards into and up the leg of a desk. The light brick was the only thing that worked. We then decided to rotat...

6/9/18 Today the attention turned to the back wheels. They were beginning to sag, so the question was, how could we do this better? After some analysis, it seemed as though the support was too long, resulting in it sagging under the weight of the robot. After a few different prototypes experimenting with wheel type and placement, we adjusted the design, simplifying the connection point to the body, and also shortening the length of the support shaft. We kept the vertical position of the wheels, also brought the wheels closer together. This helped stabilise the wheels, and also meant smoother, more steady movement. We began to consider exactly what type of environment we wanted the robot to operate in. We decided an outdoors setting over terrain on the rougher side would suit the design well. We also decided it was time to wire the sensors up. We ran cables from each sensor to the NXT brick, assessing how this fit with the design and sensor mounting rig. This wiring up went well, with...

4/9/18 With the basic structure of the robot now thought to be complete, today we decided it was time to add sensors to the robot. We envisaged that touch sensors, light sensors, and sound sensors would be best for this. Initially we attempted mounting them on the top of the motors, however this didn't really work due to the fact they were angled down and able to swivel freely. We needed something that could mount a number of sensors to the front of the robot, without falling forwards or swivelling. Nathan began a redesign of the front space between the motors. The original support structure had numerous design flaws, such as sagging, and had to go. Using angled parts and numerous connector pieces, Nathan was successful in his endeavour to create a sturdy rig capable of supporting numerous sensors in a fixed position. The touch sensor was in the central position at this point, with capacity for three more sensors to be added. We added a second touch sensor, and a sound sensor to ...

11/9/18 Today's activities mostly consisted of design testing, in which a number of conclusions were reached, resulting in changes to design. We tested the current design of the robot in an outdoors setting, which was reflective of the intention to run the robot in the outdoors. This initial test was designed to assess the function of the robot itself and how the robot responded to variations of power and rough terrain. No sensors were tested in this initial functionality test. The robot itself performed reasonably outdoors. The power presented by the dual motors was underwhelming, with the robot failing to negate even a 1cm ledge. This failure was disheartening, and meant our proposed course had to be simplified to accommodate for the apparent lack of motive power. Despite this, we tested how the robot reacted to rough surfaces such as drain meshes and uneven surfaces. The thick four wheels at the front of the robot performed well and as desired over these surfaces. We also id...

14/9/18 Today we identified that a need existed to pull the project together, ahead of the Tuesday hand-in date (4 days away). Max continued work on the presentation, while Nathan and Josh made some adjustments to the Ultrasonic program. Following some field testing, Josh and Nathan concluded that the sensor field needed to be shortened, following the detection of objects about 1 metre in the distance. They also concluded that further adjustment of the response mechanism was needed, with the reverse movement in response to object detection nowhere to be seen. We also concluded that the turning mechanism needed improvement. The sensor range was reduced from 75 centimetres to 5 centimetres. We tested again, however noticed no improvement in the detection of objects, with a previously over reactive sensor now not reacting at all to objects placed in even the immediate vicinity. Following this, the range was changed again, this time to 10cm. A reversing function was added to the program ...

13/9/18 Today, we decided to exchange the second touch sensor with the ultrasonic sensor, after it was concluded that this would be more suitable to the desired outdoors operating environment. It is envisaged that the robot will be able to negate an outdoors course, comprised of bushes and other natural elements. The ultrasonic sensor will enable us to complete this objective. We modified the front sensor rig to include the ultrasonic sensor, with the omission of the second touch sensor. This modification to the design and front structure took about 15 minutes, including disassembly, reassembly and wiring. Following the successful integration of this new sensor, we then began researching how the sensor worked and how we could code the operation of this. The intention is that the robot will drive forwards at full power, but upon the detection of objects within a 5cm length, stop, reverse, and turn 90 degrees before continuing again. Initially, we attempted some basic code to make th...