British scientists say "friendly" robots are helping them to understand how more realistic relationships might be developed between humans and androids.

A robot dubbed ERWIN (Emotional Robot with Intelligent Network) developed by computer scientists at the University of Lincoln is being used as part of a study to find out how some of the human-like thought biases in robot characteristics affect the human-robot relationship.

"Cognitive biases make humans what they are, fashioning characteristics and personality, complete with errors and imperfections," doctoral student Mriganka Biswas said.

It is thought introducing cognitive biases in a robot's characteristics makes the robot imperfect by nature, but also more human-like, he said.

"Based on human interactions and relationships, we will introduce 'characteristics' and 'personalities' to the robot," he explained. "If we can explain how human-to-human long-term relationships begin and develop, then it would be easier to plan the human-robot relationship."

In a conventional human-robot interaction, the robot's lack of identifiable characteristics and personality prevents any relationship bond developing, he said.

ERWIN, on the other hand, has the ability to express five basic emotions while interacting with a human, he said.

"Robots are increasingly being used in different fields, such as rescuing people from debris, in medical surgeries, elderly support and as an aid for people who have autism," he said.

"For the latter two especially, robots need to be friendly and relatively more sympathetic and emotive to its users," Biswas said. "A companion robot needs to be friendly and have the ability to recognize users' emotions and needs, and to act accordingly.

"So, for each category the robot needs to form a 'long-term' relationship with its users, which is possible by continuous interactions and the robot having its own personality and characteristics."