Optimal Reduced-order Modeling of Bipedal Locomotion

State-of-the-art approaches to legged locomotion are widely dependent on the use of models like the linear inverted pendulum (LIP) and the spring-loaded inverted pendulum (SLIP), popular because their simplicity enables a wide array of tools for planning, control, and analysis. However, they inevitably limit the ability to execute complex tasks or agile maneuvers. In this work, we aim to automatically synthesize models that remain low-dimensional but retain the capabilities of the high-dimensional system. For example, if one were to restore a small degree of complexity to LIP, SLIP, or a similar model, our approach discovers the form of that additional complexity which optimizes performance. In this paper, we define a class of reduced-order models and provide an algorithm for optimization within this class. To demonstrate our method, we optimize models for walking at a range of speeds and ground inclines, for both a five-link model and the Cassie bipedal robot.Comment: Submitted to ICRA 202

[[alternative]]Autonomous Dynamic Balance of Humanoid Robots(I)

計畫編號：NSC96-2218-E032-002研究期間：200708~200807研究經費：1,002,000[[abstract]]本計畫(即子計畫一)將著重於人型機器人自主動態平衡的研究，建立一 套能適應不同動作(例如，走路、上下樓梯、不平坦地面及跑步)及狀況(例 如，有無與境環互動、有無搭載重物)的機器人之動態平衡策略。相關的研 究主題包括如下：(一)機構設計，(二)伺服控制系統之設計，(三)設計動態 感知系統，(四)平坦地面走路、上下樓梯、不平坦地面走路及跑步之步態規 劃，(五)運動學及反運動學之推導，(六)以類神經網路近似反運動學，(七) 無支撐面(即跑步)動態方程式之推導，(八)單(及無)支撐面狀態之自我平 衡，(九)搭載重物與環境互動之自我平衡，及(十)具有可搭載重物及跑步能 力的人型機器人之開發。 第一年的研究主題為具有可搭載重物及跑步能力的人型機器人之機構 及伺服控制系統的設計，其中以加強伺服韌性及應用被動元件(例如，彈簧) 改善因跑步所引起地面衝擊力或搭載重物所須額外力矩；第二年的研究主 題為人型機器人之腳及手的運動學與反運動學之推導，並以類神經網路及 粒子群聚學習法則，近似具有限制的反運動學，以降低計算反運動學所須 的時間(或嵌入式系統的負荷)，亦完成單支撐面、搭載重物與環境互動狀態 之自我平衡；第三年的研究主題為無支撐面(即跑步)動態方程式之推導、 跑步步態之規劃、及自我動態平衡之策略。 配合子計畫二的雙眼可適應性視覺系統，執行子計畫四的視覺導引所要 求之動作；配合子計畫三的輸入輸出界面，設計PWM 驅動及DECODER 的PID 迴授控制之電路，並設計動態感知系統，以進行自主動態平衡；配合子計 畫四執行所下達的命令，完成所要求的智慧行為。[[sponsorship]]行政院國家科學委員

Poppy Humanoid Platform: Experimental Evaluation of the Role of a Bio-inspired Thigh Shape

International audienceIn this paper, we present an experimental evaluation of the role of the morphology in the Poppy humanoid platform. More precisely, we have investigated the impact of the bio-inspired thigh, bended of 6°, on the balance and biped locomotion. We compare this design with a more traditional straight thigh. We describe both the theoretical model and real experiments showing that the bio-inspired thigh allows the reduction of falling speed by almost 60\% (single support phase) and the decrease of the lateral motion needed for the mass transfer from one foot to the other by 30\% (double support phase). We also present an experiment where the robot walks on a treadmill thanks to the social and physical guidance of expert users and we show that the bended thigh reduces the upper body motion by about 45\% indicating a more stable walk

Systematic Controller Design for Dynamic 3D Bipedal Robot Walking.

Virtual constraints and hybrid zero dynamics (HZD) have emerged as a powerful framework for controlling bipedal robot locomotion, as evidenced by the robust, energetically efficient, and natural-looking walking and running gaits achieved by planar robots such as Rabbit, ERNIE, and MABEL. However, the extension to 3D robots is more subtle, as the choice of virtual constraints has a deciding effect on the stability of a periodic orbit. Furthermore, previous methods did not provide a systematic means of designing virtual constraints to ensure stability. This thesis makes both experimental and theoretical contributions to the control of underactuated 3D bipedal robots. On the experimental side, we present the first realization of dynamic 3D walking using virtual constraints. The experimental success is achieved by augmenting a robust planar walking gait with a novel virtual constraint for the lateral swing hip angle. The resulting controller is tested in the laboratory on a human-scale bipedal robot (MARLO) and demonstrated to stabilize the lateral motion for unassisted 3D walking at approximately 1 m/s. MARLO is one of only two known robots to walk in 3D with stilt-like feet. On the theoretical side, we introduce a method to systematically tune a given choice of virtual constraints in order to stabilize a periodic orbit of a hybrid system. We demonstrate the method to stabilize a walking gait for MARLO, and show that the optimized controller leads to improved lateral control compared to the nominal virtual constraints. We also describe several extensions of the basic method, allowing the use of a restricted Poincaré map and the incorporation of disturbance rejection metrics in the optimization. Together, these methods comprise an important contribution to the theory of HZD.PhDElectrical Engineering: SystemsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113370/1/bgbuss_1.pd

Integración de sensores a bordo del robot mini-humanoide Bioloid

En este proyecto se ha desarrollado el pie robótico ROBfoot para ser integrado en plataformas robóticas mini-humanoides. El proyecto nace en la línea de investigación de robótica mini-humanoide de la Asociación de Robótica de la Universidad Carlos III de Madrid persiguiendo aumentar las capacidades de las plataformas robóticas mini-humanoides que disponen. El pie robótico tiene la capacidad reconocer el entorno, procesar información y establecer comunicación con el controlador principal de la plataforma robótica mini-humanoide. Para ello se incorpora un completo sistema de sensorización y se integra un microcontrolador que desempeña la función de controlador del pie robótico, analizando la información de los sensores y comunicandose con el controlador de la plataforma mini-humanoide. El robot mini-humanoide con el pie robótico instalado aumenta su versatilidad al ser posible la programación de nuevas habilidades antes impracticables. Se persigue dotar de la habilidad de ascender y descender por una escalera de manera autónoma y el pie robótico debe tener la capacidad detectar y posicionar los escalones de dicha escalera. Se persigue no obstante el diseño de un pie robótico completo y funcional que sea apto para desempeñar otras funciones y de servir en investigaciones de robótica humanoide. El pie robótico desarrollado ha sido empleado en el concurso nacional de robots mini-humanoides CEABOT donde su funcionamiento ha sido verificado y su utilidad confirmada.ROBfoot, the robotic foot designed for mini-humanoid robots has been developed in this project The project arises inside the mini-humanoids investigation group of Carlos III University of Madrid Robotics Association in order to increase the mini-humanoid robots’ capabilities they posses. The robotic foot recognises the enviroment, processes the information and stablishes communication with the mini-humanoid robot’s main controller. To accomplish this, a complete sensor system is embodied and a microcontroller which acts as the robotic foot’s controller, analyzing information and communicating with the mini-humanoid’s main controller, is integrated. The mini-humanoid robot increases its versatility with the robotic foot installed as new habilities, which their establishment where impossible before, can be programmed. It is pursued to grant the hability to automously climb a stair, so the robotic foot must have the capability to detect the steps of a stair. However, it is intended to design a complete and functional robotic foot able to perform other functions and be useful in humanoid robotics investigations. The robotic foot was used in the national mini-humanoid robotics championship CEABOT where its functioning was verified and its serviceability confirmed.Ingeniería Electrónica Industrial y Automátic