Abstract: A control system for a bipedal humanoid robot that utilizes certain fundamental characteristics of bipedal motion to provide a robust and relatively simple balancing and walking mechanism. The system primarily utilizes the concept of “capturability,” which is defined as the ability of the robot to come to a stop without falling by taking N or fewer steps. This ability is considered crucial to legged locomotion and is a useful, yet not overly restrictive criterion for stability. In the preferred embodiment, the bipedal robot is maintained in a 1-step capturable state. This means that future step-locating and driving decisions are made so that the robot may always be brought to a balanced halt with the taking of one step. Other embodiments maintain the bipedal robot in an N-step capturable state, in which the robot may always be brought to a balanced halt by taking N or fewer steps.

Abstract: A control system for a bipedal humanoid robot that utilizes certain fundamental characteristics of bipedal motion to provide a robust and relatively simple balancing and walking mechanism. The system primarily utilizes the concept of “capturability,” which is defined as the ability of the robot to come to a stop without falling by taking N or fewer steps. This ability is considered crucial to legged locomotion and is a useful, yet not overly restrictive criterion for stability. In the preferred embodiment, the bipedal robot is maintained in a 1-step capturable state. This means that future step-locating and driving decisions are made so that the robot may always be brought to a balanced halt with the taking of one step. Other embodiments maintain the bipedal robot in an N-step capturable state, in which the robot may always brought to a balanced halt by taking N or fewer steps.

Abstract: A system and method is disclosed for controlling a robot having at least two legs, the robot subjected to an event such as a push that requires the robot to take a step to prevent a fall. In one embodiment, a current capture point is determined, where the current capture point indicates a location on a ground surface that is the current best estimate of a stepping location for avoiding a fall and for reaching a stopped state. The robot is controlled to take a step toward the current capture point. After taking the step, if the robot fails to reach a stopped state without taking any additional steps, an updated current capture point is determined based on the state of the robot after taking the step. The current capture points can be stored in a capture point memory and initialized based on a model of the robot.

Abstract: A system and method is disclosed for controlling a robot having at least two legs, the robot subjected to an event such as a push that requires the robot to take a step to prevent a fall. In one embodiment, a current capture point is determined, where the current capture point indicates a location on a ground surface that is the current best estimate of a stepping location for avoiding a fall and for reaching a stopped state. The robot is controlled to take a step toward the current capture point. After taking the step, if the robot fails to reach a stopped state without taking any additional steps, an updated current capture point is determined based on the state of the robot after taking the step. The current capture points can be stored in a capture point memory and initialized based on a model of the robot.