Can UserCentered Reinforcement Learning Allow a Robot to Attract Passersby without Causing Discomfort? * The aim of our study is to develop a method by which a social robot can greet passersby and get their attention without causing them to suffer discomfort. Social robots now function in a number of customer service roles, such as receptionists, guides, and exhibitors. However, sudden greetings from a robot can startle passersby. Therefore, we developed a method that allows social robots to adapt their mannerisms situationally based the results of related work. Our proposed method, usercentered reinforcement learning, enables robots to greet passersby without causing them discomfort (pu003c0.01). Our field experiment in an office entrance demonstrated that our method meets this requirement.

Enthusiastic Robots Make Better Contact This paper presents the design and evaluation of humanlike welcoming behaviors for a humanoid robot to draw the attention of passersby by following a threestep model: (1) selecting a target (person) to engage, (2) executing behaviors to draw the targetxe2x80x99s attention, and (3) monitoring the attentive response. A computer vision algorithm was developed to select the person, start the behaviors and monitor the response automatically. To vary the robotxe2x80x99s enthusiasm when engaging passersby, a waving gesture was designed as basic welcoming behavioral element, which could be successively combined with an utterance and an approach movement. This way, three levels of enthusiasm were implemented: Mild (waving), moderate (waving and utterance) and high (waving, utterance and approach movement). The three levels of welcoming behaviors were tested with a Pepper robot at the entrance of a university building. We recorded data and observation sheets from several hundreds of passersby (N 364) and conducted postinterviews with randomly selected passersby (N 28). The level selection was done at random for each participant. The passersby indicated that they appreciated the robot at the entrance and clearly recognized its role as a welcoming robot. In addition, the robot proved to draw more attention when showing high enthusiasm (i.e., more welcoming behaviors), particularly for female passersby.