Animals locomote robustly and agile, albeit significant sensorimotor delays of their nervous system. The sensorimotor control of legged robots is implemented with much higher frequencies-often in the kilohertz range-and sensor and actuator delays in the low millisecond range. But especially at harsh impacts with unknown touch-down timing, legged robots show unstable controller behaviors, while animals are seemingly not impacted. Here we examine this discrepancy and suggest a hybrid robotic leg and controller design. We implemented a physical, parallel joint compliance dimensioned in combination with an active, virtual leg length controller. We present an extensive set of systematic experiments both in computer simulation and hardware. Our hybrid leg and controller design shows previously unseen robustness, in the presence of sensorimotor delays up to 60 ms, or control frequencies as low as 20 Hz, for a drop landing task from 1.3 leg lengths high and with a passive compliance ratio of 0.7. In computer simulations, we report successful drop-landings of the hybrid compliant leg from 3.8 leg lengths (1.2 m) for a 2 kg quadruped robot with 100 Hz control frequency and a sensorimotor delay of 35 ms. The results of our presented hybrid leg design and control provide a further explanation for the performance robustness of animals, and the resulting discrepancy between animals and legged robots.

翻译：动物在神经系统中出现强力和敏捷的动作,尽管其神经系统存在重大的感知力延迟。对腿部机器人的感官模控器在千赫射程和感应器的频率常高得多的情况下,在低毫秒的射程和感应器延迟时,执行频率高得多。特别在触地降时间不为人知的严酷的冲击下,脚部机器人表现出不稳定的控制器行为,而动物似乎没有受到影响。我们在这里检查这一差异,并建议采用混合机器人腿和控制器的设计。我们与一个活跃的、虚拟腿长控制器一起实施了一个物理、平行的联合合规层面。我们在计算机模拟和硬件中展示了一套广泛的系统实验。我们的混合腿和控制器设计显示以前看不见的稳健健性,在感应机能延迟达60米或控制频率低至20赫兹的频率下,在1.3腿长的着陆任务时,其被动合规率为0.7。在计算机模拟中,我们报告了从3.8腿长(1.2米)处成功降落符合混合腿的腿部(1.2米),我们展示了一套2公斤四重的腿模拟和硬脚部机器人。我们使用的机械控制频率和感应变的操作结果为35提供了稳性感测结果。