Shape of things to comeRules of war to be programmed into robots' decision making

The United States and other countries rely more and more on robots to carry out military missions. These robots are still controlled by humans, but military services, eager to achieve greater effectiveness, look for ways to give these robots autonomous decision making capabilities. There are worries, though: giving robots the freedom to choose when to open fire and on whom may be more effective militarily, but it also open to door for even more killings of civilians and innocent bystanders.

Robotics engineer Ron Arkin at the Georgia Institute of Technology is working on solving this problem. He is trying to imagine wars in which weapons make their own decisions about wielding lethal force. He is particularly interested in how such machines might be programmed to act ethically, obeying the rules of engagement. Arkin has developed an “ethical governor” which aims to ensure that robot attack aircraft behave ethically in combat, and is demonstrating the system in simulations based on recent campaigns by U.S. troops, using real maps from the Middle East.

Tom Simonite writes that in one scenario, modeled on a situation encountered by U.S. forces in Afghanistan in 2006, the drone identifies a group of Taliban soldiers inside a defined “kill zone.” The drone, however, does not fire. Its maps indicate that the group is inside a cemetery, so opening fire would breach international law. In another scenario, the drone identifies an enemy vehicle convoy close to a hospital. Here the ethical governor only allows fire that will damage the vehicles without harming the hospital. Arkin has also built in a “guilt” system which, if a serious error is made, forces a drone to start behaving more cautiously (see videos of these simulations on Arkin’s Web site).

Simonite writes that in developing the software, Arkin drew on studies of military ethics, as well as discussions with military personnel, and says his aim is to reduce non-combatant casualties. One Vietnam veteran told him of soldiers shooting at anything that moved in some situations. “I can easily make a robot do that today, but instead we should be thinking about how to make them perform better than that,” Arkin says.

Simulations are a powerful way to imagine one possible version of the future of combat, says Illah Nourbakhsh, a roboticist at Carnegie Mellon University. They gloss, however, over the complexities of getting robots to understand the world well enough to make such judgments, he says; something unlikely to be possible for decades.

Arkin stresses that his research, funded by the U.S. army, is not designed to develop prototypes for future battlefield use. “The most important outcome of my research is not the architecture, but the discussion that it stimulates.” He maintains, however, that the development of machines that decide how to use lethal force is inevitable, making it important that when such robots do arrive they can be trusted. “These ideas will not be used tomorrow, but in the war after next, and in very constrained situations.”

Roboticist Noel Sharkey at Sheffield University campaigns for greater public discussion about the use of automating in war. “I agree with Ron that autonomous robot fighting machine look like an inevitability in the near future,” he told Simonite. Arkin’s work shows the inadequacy of our existing technology at dealing with the complex moral environment of a battlefield, says Sharkey. “Robots don’t get angry or seek revenge but they don’t have sympathy or empathy either,” he says. “Strict rules require an absolutist view of ethics, rather than a human understanding of different circumstances and their consequences.”

Yet, in some circumstances, a strict rule-based approach is valuable. The Georgia Tech group has also made a system that advises a soldier of the ethical constraints on a mission as they program it into an autonomous drone. That kind of tool could see practical use much sooner, says Nourbakhsh: “Similar systems exist to help doctors understand the medical ethics of treatments.”

Arkin will discuss his latest results at the AUVSI Unmanned Systems conference in Washington, D.C., in August.