The most significant risk for the team at this point is that we have not actually implemented very much yet. We have spent most of our time on design, and have not yet seen how everything will work in practice, so there could be unexpected problems that will arise. Additional risks include remaining uncertainty in the designs for the powering subsystem and for the global path planning algorithm.
There was one main change to the design since the previous status report. This has to do with obstacle detection for local path planning. Since the Lidar scanner may be too high off the ground to detect short obstacles, we determined that an additional sensor was needed closer to the ground for use in local path planning to allow the robot to avoid these obstacles. We decided to use an ultrasonic sensor since it is cheap and simple to use, while also being effective for the necessary task. There was enough extra money in the budget for this sensor, so the most significant cost is that it is an additional component to set up, which we believe we can handle since it should be relatively easy to use.