Humanoid robots are used as a research tool to understand bipedal locomotion. When pushed, a humanoid robot must be able to avoid falling and return to a balanced configuration. This is called push recovery and can be achieved using proper foot placement. Depending on the freedom of movement, one or multiple steps are taken to accomplish this goal. It is expected that foot placement can also be...

This paper presents an adaptive two-level control strategy for a biped walking model and demonstrates its performance in a wide range of walking modes with considerably diverse model and control parameter settings. Proposed control strategy inherits a push off that resembles considerably to forceful extension of the trailing leg during push off in human locomotion and represents a very importan...

Samsung Electronics Co., Ltd. has been developing humanoid robots for years. Roboray, the latest developed humanoid robot in Fig. 1, has many different characteristics from the previous robots, e.g. Mahru series [1]. The main difference is that Roboray can be torque-controlled with torque sensors at all joints in the lower limbs. There exist some released biped robots which have torque/force co...

Before succumbing to slower speeds, older adults may walk with a diminished push-off to prioritize stability over mobility. However, direct evidence for trade-offs between push-off intensity and balance control in human walking, independent of changes in speed, has remained elusive. As a critical first step, we conducted two experiments to investigate: (i) the independent effects of walking spe...

Amputees using passive ankle-foot prostheses tend to expend more metabolic energy during walking than non-amputees, and reducing this cost has been a central motivation for the development of active ankle-foot prostheses. Increased push-off work at the end of stance has been proposed as a way to reduce metabolic energy use, but the effects of push-off work have not been tested in isolation. In ...

We present methods for extracting a fast indicator for push-recovery strategy selection from the data of an inertial measurement unit mounted on a human or humanoid torso. The methods serve the purposes of detecting the beginning, the direction and intensity of the push as well as predicting the feasible recovery strategy. We test our methods on a dataset of 78 push-recovery trials collected wi...

1 Introduction The ankle delivers about half of the total mechanical work during walking. Lower-limb amputees using conventional passive-elastic prostheses experience 20 to 30% higher metabolic cost than able-bodied individuals, perhaps because these prostheses do not provide net positive work during the course of a step [1]. To address this problem, companies are developing battery-powered pro...

Today, often ankle’s active prosthesis is used for transtibial amputated people’s walking, because these prostheses have some advantages such as increasing power and decreasing metabolism. In most of active prosthesis in order to create a movement or increase the force at the push-off, electrical actuators are used like a motor. In cases where a higher-power motor is necessary, the capacity, we...

This paper presents a two-level control strategy for bipedal walking mechanism that accounts for implicit control of push-off on the between-step control level and tracking of imposed holonomic constraints on kinematic variables via feedback control on within-step control level. The proposed control strategy was tested in a biologically inspired model with minimal set of segments that allows ev...