Seawolf IV was a refinement of the design used in Seawolf III. It was built as a way to familiarize new members of the club with underwater robotics as well as allow them to have a sense of attachment to the robot. Similarities between the two designs include the use of 80/20 extruded aluminum to construct the frame, the use of a pelican case to house the electronics, and the use of a Lenovo netbook as the computer used to run the robot.
The mechanical design of the chassis of Seawolf IV was focused on two things, the switch to a different sized pelican case and to use the modular aspect of the 80/20 frame. The change of pelican case and redesign of the frame allowed for Seawolf IV to have a smaller foot print as well as be lighter than Seawolf III. One of the other new features on Seawolf IV was a firewire camera which was housed in a waterproof PVC enclosure. Many of the other features such as the dropper, USB camera, and the thrusters and their mounts were able to be reused from Seawolf III.
Seawolf IV's electronics include a Lenovo S10 netbook as well as custom made power board, motor board, and peripheral board. In addition to the cameras, Seawolf IV also featured two additional sensors, an IMU and a pressure transducer. The robot was powered from three lead acid batteries, two for the thrusters and one for the remaining electrical systems.
Seawolf IV continued to use the libseawolf software platform that was initially developed during the use of Seawolf III. One major addition was the facilities to write parts of the software in Python, while keeping other parts in C. This switch to a mixed language environment with C and Python interoperating seamlessly was a huge boost to the software development process, as high level code could be written easily in Python. Another major improvement was the separation of the mission control and vision systems. This allowed them to be more easily developed and debugged.
Lenovo S10 Netbook
80/20 Aluminum Extrusion