Physically safe programming

Physically safe programming
Rice-led project lands $1M in new grants to build safer robots

BY JADE BOYD
Rice News Staff

Anyone who’s ever lost half a day’s work when their computer unexpectedly locked up is all too familiar with the mental anguish that faulty software can cause. Thankfully, the pain isn’t physical — but what if it were?

Software enabled machines interact with the physical world every day, said Rice computer scientist Walid Taha. Some of these systems are complex, including entire robotic assembly lines. Other well-known examples include NASA’s Mars rovers and the military’s use of unmanned flying drones. But the number of everyday devices that are controlled by specialized software running on dedicated microcontrollers is growing. Examples include gauges that measure water levels on bayous around Houston and temperature gauges that control fans and chargers in laptop computers.

“Software is becoming a critical component of almost every appliance and device around us,” Taha said. “That has terrific advantages for automating processes, but it also carries serious risks. Software is extremely fragile — an unintended setting for just one bit of information can alter the safe operation of almost any system.”

JEFF FITLOW

From left: Rice robotics expert Marcia O’Malley, University of Houston computer scientist Albert Cheng and Rice computer scientist Walid Taha are collaborating on ways to program robots to operate more safely. In a recent visit to O’Malley’s lab, Taha tested a robotic application with the help of Rochelle Mellish, a Princeton University sophomore participating in a Rice’s summer program.

Taha, assistant professor of computer science, said society is rapidly becoming more and more dependent both on software embedded in individual devices and on the much more complex programs that control everything from vehicles to whole factories.

Numerous examples of systems that directly impact the physical safety of people come from the realm of medicine. Doctors already use robotic systems to operate on patients, and experts are developing systems that will allow surgeons to operate remotely from another hospital or city. Taha said it is not unheard of for robots in factories to tear themselves apart when other failures occur on the assembly line, so finding a way to make sure robots carry out tasks like surgery in a safe way is a paramount concern.

Taha and a team of colleagues from Rice, Yale University and the University of Houston (UH) have established the Physically Safe Computing project to develop programming languages, tools, and methods that software designers can use to guarantee physical safety. These new methods will make it possible to take into account — from the very start of the software design process — the physical environment where the software will be embedded.

The project aims to push this idea to the point that machine-checkable proofs certifying the physical safety of the software can be generated automatically. The project is highly interdisciplinary and involves two other Rice faculty: computer scientist Robert “Corky” Cartwright and robotics expert Marcia O’Malley, as well as UH computer scientist Albert Cheng and Yale computer scientist Paul Hudak.

JEFF FITLOW

The Physically Safe Computing Project will test new software languages and programming tools using telesurgery software developed by Rice’s Mechatronics and Haptic Interfaces Lab.

Funding for the project comes from several national and industrial sources, including the National Science Foundation (NSF), Schlumberger and LogicBlox. This year the project has attracted more than $1 million in new awards.

“Addressing the challenge of physically safe computing requires bringing together ideas from control theory, language design, program verification, program generation, software engineering, and real-time and embedded systems,” Taha explained. “We have to apply what we learn in each of these areas to build a framework that can be applied very broadly.”

To demonstrate the effectiveness of the results of this research in a realistic setting, the investigators plan to evaluate telesurgery applications developed by O’Malley’s Mechatronics and Haptic Interfaces Laboratory in the mechanical engineering and materials science department.

“We hope to recruit some undergraduates this fall,” Taha said. “We are looking for talented students interested in mechanics, physics, programming languages, real-analysis and mechanically checkable proofs.”

The project also has openings for two doctoral students and one postdoctoral researcher.