ABSTRACT Compliance became the essential part of locomotion in robotics. Due to ability of storin... more ABSTRACT Compliance became the essential part of locomotion in robotics. Due to ability of storing and releasing energy, compliance can be used for energy efficiency or reducing impact during ground collision and gaining robustness. On the other side, natural/passive dynamics are important because by exploiting such dynamics, energy efficiency will be assured. Therefore it is crucial to understand how compliance changes natural dynamics of a system. After this inspection, natural dynamics exploitation can be more straightforward through developing tools like adaptive oscillators.
ABSTRACT We compare the effects of linear and piecewise linear compliant spines on locomotion per... more ABSTRACT We compare the effects of linear and piecewise linear compliant spines on locomotion performance of quadruped robots in terms of energy efficiency and locomotion speed through a set of simulations and experiments. We first present a simple locomotion system that behaviorally resembles a bounding quadruped with flexible spine. Then, we show that robots with linear compliant spines have higher locomotion speed and lower cost of transportation in comparison with those with rigid spine. However, in linear case, optimal speed and minimum cost of transportation are attained at very different spine compliance values. Moreover, it is verified that fast and energy efficient locomotion can be achieved together when the spine flexibility is piecewise linear. Furthermore, it is shown that the robot with piecewise linear spine is more robust against changes in the load it carries. Superiority of piecewise linear spines over linear and rigid ones is additionally confirmed by simulating a quadruped robot in Webots and experiments on a crawling two-parts robot with flexible connection.
The ability to follow one another’s gaze plays an important role in our social cognition; especi... more The ability to follow one another’s gaze plays an important role in our social cognition; especially when we synchronously perform tasks together. We investigate how gaze cues can improve performance in a simple coordination task (i.e., the mirror game), whereby two players mirror each other’s hand motions. In this game, each player is either a leader or follower. To study the effect of gaze in a systematic manner, the leader’s role is played by a robotic avatar. We contrast two conditions, in which the avatar provides or not explicit gaze cues that indicate the next location of its hand. Specifically, we investigated (a) whether participants are able to exploit these gaze cues to improve their coordination, (b) how gaze cues affect action prediction and temporal coordination, and (c) whether introducing active gaze behavior for avatars makes them more realistic and human-like (from the user point of view).
ABSTRACT Compliance became the essential part of locomotion in robotics. Due to ability of storin... more ABSTRACT Compliance became the essential part of locomotion in robotics. Due to ability of storing and releasing energy, compliance can be used for energy efficiency or reducing impact during ground collision and gaining robustness. On the other side, natural/passive dynamics are important because by exploiting such dynamics, energy efficiency will be assured. Therefore it is crucial to understand how compliance changes natural dynamics of a system. After this inspection, natural dynamics exploitation can be more straightforward through developing tools like adaptive oscillators.
ABSTRACT We compare the effects of linear and piecewise linear compliant spines on locomotion per... more ABSTRACT We compare the effects of linear and piecewise linear compliant spines on locomotion performance of quadruped robots in terms of energy efficiency and locomotion speed through a set of simulations and experiments. We first present a simple locomotion system that behaviorally resembles a bounding quadruped with flexible spine. Then, we show that robots with linear compliant spines have higher locomotion speed and lower cost of transportation in comparison with those with rigid spine. However, in linear case, optimal speed and minimum cost of transportation are attained at very different spine compliance values. Moreover, it is verified that fast and energy efficient locomotion can be achieved together when the spine flexibility is piecewise linear. Furthermore, it is shown that the robot with piecewise linear spine is more robust against changes in the load it carries. Superiority of piecewise linear spines over linear and rigid ones is additionally confirmed by simulating a quadruped robot in Webots and experiments on a crawling two-parts robot with flexible connection.
The ability to follow one another’s gaze plays an important role in our social cognition; especi... more The ability to follow one another’s gaze plays an important role in our social cognition; especially when we synchronously perform tasks together. We investigate how gaze cues can improve performance in a simple coordination task (i.e., the mirror game), whereby two players mirror each other’s hand motions. In this game, each player is either a leader or follower. To study the effect of gaze in a systematic manner, the leader’s role is played by a robotic avatar. We contrast two conditions, in which the avatar provides or not explicit gaze cues that indicate the next location of its hand. Specifically, we investigated (a) whether participants are able to exploit these gaze cues to improve their coordination, (b) how gaze cues affect action prediction and temporal coordination, and (c) whether introducing active gaze behavior for avatars makes them more realistic and human-like (from the user point of view).
Uploads
Papers by Mahdi Khoramshahi