This blog post is coauthored by Dionisio de Niz.
Software with timers and clocks (STACs) exchange clock values to set timers and perform computation. STACs are key elements of safety-critical systems that make up the infrastructure of our daily lives. They are particularly used to control systems that interact (and must be synchronized) with the physical world. Examples include avionics systems, medical devices, cars, cell phones, and other devices that rely on software not only to produce the right output, but also to produce it at the correct time. An airbag, for example, must deploy as intended, but just as importantly, it must deploy at the right time. Thus, when STACs fail to operate as intended in the safety-critical systems that rely on them, the result can be significant harm or loss of life. Within the Department of Defense (DoD), STACs are used widely, ranging from real-time thread schedulers to controllers for missiles, fighter planes, and aircraft carriers. This blog post presents exploratory research to formally verify safety properties of sequential and concurrent STACs at the source-code level.
The growth and change in the field of robotics in the last 15 years is tremendous, due in large part to improvements in sensors and computational power. These sensors give robots an awareness of their environment, including various conditions such as light, touch, navigation, location, distance, proximity, sound, temperature, and humidity. The increasing ability of robots to sense their environments makes them an invaluable resource in a growing number of situations, from underwater explorations to hospital and airport assistants to space walks. One challenge, however, is that uncertainty persists among users about what the robot senses; what it predicts about its state and the states of other objects and people in the environment; and what it believes its outcomes will be from the actions it takes. In this blog post, I describe research that aims to help robots explain their behaviors in plain English and offer greater insights into their decision making.