Comparison of kinematic and dynamic leg trajectory optimization techniques for biped robot locomotion

The paper presents comparison analysis of two approaches in defining leg trajectories for biped locomotion. The first one operates only with kinematic limitations of leg joints and finds the maximum possible locomotion speed for given limits. The second approach defines leg trajectories from the dynamic stability point of view and utilizes ZMP criteria. We show that two methods give different trajectories and demonstrate that trajectories based on pure dynamic optimization cannot be realized due to joint limits. Kinematic optimization provides unstable solution which can be balanced by upper body movement

Kinematic and dynamic approaches in gait optimization for humanoid robot locomotion

© Springer International Publishing AG 2018. Humanoid robot related research keeps attracting many researchers nowadays because of a high potential of bipedal locomotion. While many researchers concentrate on a robot body movement due to its direct contribution to the robot dynamics, the optimality of a leg trajectory has not been studied in details yet. Our paper is targeted to decrease this obvious gap and deals with optimal trajectory planning for bipedal humanoid robot walking. The main attention is paid to maximization of locomotion speed while considering velocity, acceleration and power limitations of each joint. The kinematic and dynamic approaches are used to obtain a desired optimal trajectory. Obtained results provide higher robot performance comparing to commonly used trajectories for control bipedal robots

Perception of animacy and direction from local biological motion signals.

We present three experiments that investigated the perception of animacy and direction from local biological motion cues. Coherent and scrambled point-light displays of humans, cats, and pigeons that were upright or inverted were embedded in a random dot mask and presented to naive observers. Observers assessed the animacy of the walker on a six-point Likert scale in Experiment 1, discriminated the direction of walking in Experiment 2, and completed both the animacy rating and the direction discrimination tasks in Experiment 3. We show that like the ability to discriminate direction, the perception of animacy from scrambled displays that contain solely local cues is orientation specific and can be well-elicited within exposure times as short as 200 ms. We show further that animacy ratings attributed to our stimuli are linearly correlated with the ability to discriminate their direction of walking. We conclude that the mechanisms responsible for processing local biological motion signals not only retrieve locomotive direction but also aid in assessing the presence of animate agents in the visual environment