Bipedal Robot

• Subject Area: Systems Engineering
• Term: Funded in 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 503679668

With this proposal, we seek to acquire a state-of-the-art bipedal robot to study dynamic legged locomotion. Our overall scientific goal is to improve the performance of today’s legged robots with respect to their speed, efficiency, and versatility. In this context, our research is specifically targeted at the question of how to exploit the mechanical dynamics of such a robot to improve its performance. That is, we seek to understand how a legged robot can benefit from motions driven by gravity, inertia, and elastic oscillations to reduce the amount of energy used, to improve peak power output, or to aid with stability. We are also interested in the usage of different gaits, such as walking or running.These goals are inspired by biological systems: humans and animals show remarkable performance with regard to locomotion and they do so by cleverly exploiting the dynamics of their body. We seek to enable these abilities in robotic systems, by first using conceptual models, simulations, and model-based optimizations to understand the fundamental physical principles that drive the exploitation of mechanical dynamics in nature. For example, we have already been able to demonstrate, how using different gaits can substantially reduce energy consumption and increase locomotion speed of future legged robots. Incorporating these fundamental principles, we then develop control approaches to realize the same gains on real robots. This is an important step, as performance criteria such as speed, efficiency, and versatility only fully manifest themselves in actual hardware implementations.To this end, we seek to acquire a commercial-grade, bipedal robotic research platform that is capable of autonomous dynamic legged locomotion. That is, its power-to-weight ratio is such that running and hopping gaits are possible. The robot has fully actuated joints at its hip, knees, and ankles. These joints are torque driven to facilitate control, while actuators only exhibit a small reflected inertia to emphasize the natural dynamics of the mechanical structure. On-board sensors allow monitoring all joints, estimating the posture of the robot via an inertial measurement unit, and surveying the ground in front of the robot in three dimensions. Sensors and actuators are directly accessible within an open-access low-level application programming interface for the development of custom control algorithms. The robot forms a unit with an experimental environment consisting of a computer-controlled instrumented treadmill which can record ground reaction forces, a visual motion capture system, and an overhead gantry. This environment will allow for safe and effective experimentation and the instruments will deliver ground truth measurements of the state of the robot. These are imperative for calibration and validation purposes and can be further used for control. The measured kinematics and kinetics are also a main characteristic of different gaits, a core focus of our work.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Zweibeiniger Roboter
• Instrumentation Group: 2320 Greif- und Hebewerkzeuge, Verladeeinrichtungen
• Applicant Institution: Universität Stuttgart
• Leader: Professor Dr. C. David Remy