Date:
25/11 2010
Duration of activity:
3 hours
Group members participating:
Frederik, Christian & Lasse
Goals:
Discuss and describe possible end course projects and end up having one selected
Plan:
Make a description of three possible end course projects containing a description, overall architecture and point out some potential problems.
Results:
After a discussion we came up with the three following projects:
This would require the robot wagons to keep a fixed distance to the wagon ahead but also to follow its direction. Ultrasonic sensors could be used both to measure the distance but also to ensure that the wagon ahead is between two ultrasonic sensors. Experiments with other sensors such as cameras and light sensors could also be done. The leader car could be driving randomly around or be controlled by a joystick or a Wii remote via a PC.
A sketch of a possible system setup is seen on figure 1 below:
Figure 1 - Possible architecture of the Lego convoy project
The main challenge would be to keep the direction with the wagon ahead, though it should be possible to accomplish a three-wagon convoy controlled with a Wii remote (via Bluetooth) that maintains a fixed distance between the wagons and lets the lead wagon control the direction.
2. Balancing robot experiments
We would take the issues identified in previous lab sessions with balancing robots as a starting point and experiment with diferent ways of keeping balance. How effective would it be to regulate using a balancing stick instead of the motors? The main problem with our previous work with the balancing robot was the inaccuracy of the light sensor as a means of regulating balance. The alternative methods for balancing a robot could maybe complement the existing sejway motor-approach in a 2-axis balancing robot.
Figure 2 - Different regulation methods for maintaining balance. a) Regulating the wheels by motors b) Using a slider to change the balance c) Make a stick swing to change the balance.
The addition of a second axis will be a challenge and will require a lot of experimenting with different sensors and regulation methods. Another goal for this project could be to introduce another or several other sensor(s) to measure the attitude thereby limiting the inaccuracy of our previous attempts. The main goal for this project will be to have a balancing robot working with diferent methods for balancing. Best case scenario is a 2-axis balancing robot that is able to correct for falls in 2 axis.
3. Gene inheritance among a flock of robots
The idea is to have some robot parents each with a set of genes that can be mixed when they have a baby. The parents should then mate several times and have children with different behaviours based on the genes of the parents.
The transferring of genes can be handled by a server PC which distributes the genes to the parents and the parents then combine their genes which is sent to a "baby robot". The challenge in this project is to handle the level of complexity because the definition and exchange of genes can easily get complex when new genes are introduced. A subsumption architecture can be used to define the priority of the different behaviours for each robot - an example is shown below:
Figure 3 - Example of a set of genes and the matching behaviours
A sketch of a possible system setup can be seen on figure 4 below:
Figure 4 - A proposal for a system with a flock of mating robots with inherited genes
Conclusion:
We ended up choosing the Balancing robot experiments because we were interested in improving the robot from the lab sessions, but also to investigate whether it is possible to add an axis and still make the robot balance satisfactory. In the lab sessions light sensors were used but we will also try to combine with other sensors such as a gyroscope. Alternatives to motor regulation for balancing will also be investigated as shown on Figure 2. The construction of the robot will also have a lot to say, which will lead to experiments with the construction of the robot. Because similar projects have been done in the previous years there should be plenty of inspiration.