13 accepted papers
In this work, we investigate and validate two methods that can extend the explosive motion capabilities of series elastic actuated robots during standing jumps. First, field weakening control is exploited on multiple joints of a monoped to boost their peak velocities. However, field weakening operat
The flexibility and adaptability of modular and re-configurable robots opens up new opportunities for on-demand robot morphology optimization for varying tasks. In particular, multi-arm robotic systems can expand the solution space for any given task. In this paper, we present a novel approach to ex…
Torque distribution in redundant robots that combine the potential of asymmetric series-parallel actuated branches and multi-articulation pose a non-trivial challenge. To address the problem, this work proposes a novel optimization based controller that can accommodate various quadratic criteria to…
Despite the development of a large number of mobile manipulation robots, very few platforms can demonstrate the required strength and mechanical sturdiness to accommodate the needs of real-world applications with high payload and moderate/harsh physical interaction demands, e.g., in disaster-respons
This paper investigates the energy efficiency potential of continuously controllable clutches between the motors and links of robot joints. Inspired by biological muscles, the clutch enables free, purely gravity driven robot link motion phases gradually disengaged from gear friction, not requiring m…
We consider the global tracking control problem of robots with elastic joints. Even if joint elasticity introduces beneficial features for modern applications which require physically resilient and safer robots that can interact with the environment or humans, it challenges the achievable control pe…
Developing a high physical performance robotic manipulation platform with considerable power density, strength and resilience is not a trivial task and frequently leads to heavy and bulky systems unable to meet the application requirements, i.e. such robots should have human body size compatibility…
Joint torque sensing represents one of the foundations and vital components of modern robotic systems that target to match closely the physical interaction performance of biological systems through the realization of torque controlled actuators. However, despite decades of studies on the development
Series-elastic actuators are quickly becoming the core component of robots operating in real-world environments, allowing for robust, safe, torque-controlled robots. This letter investigates the influence of the selected stiffness and control parameters. By consolidating several analyses, it is show
The paper proposes a method to assess the feasible torque bandwidth for electrically driven torque controllable actuators over its entire torque amplitude range. The method solely relies on the knowledge of hardware parameters and thereby determines the physically feasible torque control bandwidth a…
This contribution compares two approaches for applying disturbance observers (DOBs) to the torque control problem of series elastic actuators (SEAs). It is demonstrated that they are in fact equivalent for linear models in terms of their ability to reject disturbances and enforce nominal model dynam…
The work discusses two control concepts. Both approach oscillation damping for elastic link robotic arms from fundamentally different theoretical directions. Despite their principal difference, the work consolidates both control schemes by mathematically deriving the equivalence of the resulting con
Link elasticity is commonly understood to be a detrimental side-effect of imperfect mechanical designs of robotic arms and comparable machinery. In contrast to this notion, this paper demonstrates a novel approach to exploit intrinsic robot link compliance in order to estimate a priori unknown paylo…