Robots are used increasingly often in safety-critical scenarios, such as robotic surgery or human–robot interaction. To ensure stringent performance criteria, formal controller synthesis is a promising direction to guarantee that robots behave as desired. However, formally ensured properties only transfer to the real robot when the model is appropriate. In this article, we address this problem by combining the identification of a reachset-conformant model with controller synthesis. Since the reachset-conformant model contains all the measured behaviors of the real robot, the safety properties of the model transfer to the real robot. The transferability is demonstrated by experiments on a real robot, for which we synthesize tracking controllers.

Current safety mechanisms implementing industry standards for human-robot coexistence separate humans and robots through caging. Other approaches allowing humans to enter the workspace of manipulators do not provide formal safety guarantees. Thus, this study aims to facilitate the widespread adoption of collaborative robots by presenting SaRA, an extensible tool that performs set-based reachability analysis and formally guarantees safety. Our experimental results show that the set-based prediction of a human can be computed in a few microseconds, using SaRA, allowing for real-time consideration of many surrounding humans in an environment.

Humans must remain unharmed during their interaction with robots. We present a new method guaranteeing impact force limits when humans and robots share a workspace. Formal guarantees are realized using an online verification method, which plans and verifies fail-safe maneuvers through predicting reachable impact forces by considering all future possible scenarios. We model collisions as a coupled human-robot dynamical system with uncertainties and identify reachset-conforming models based on real-world collision experiments. The effectiveness of our approach for human-robot co-existence is demonstrated for the human hand interacting with the end effector of a six-axis robot manipulator with force sensing. By integrating a human pose detection system, the efficiency of robot movements increases.

Flexible manufacturing and automation require robots that can be adapted to changing tasks. We propose to use modular robots that are customized from given modules for a specific task. This work presents an algorithm for proposing a module composition that is optimal with respect to performance metrics such as cycle time and energy efficiency, while considering kinematic, dynamic, and obstacle constraints. Tasks are defined as trajectories in Cartesian space, as a list of poses for the robot to reach as fast as possible, or as dexterity in a desired workspace. In a simulated comparison with commercially available industrial robots, we demonstrate the superiority of our approach in randomly generated tasks with respect to the chosen performance metrics. We use our modular robot proModular.1 for the comparison.

Model-based design of robotic systems has many advantages, among them faster development cycles and reduced costs due to early detections of design flaws. Approximate models are sufficient for many classical robotic applications; however, they no longer suffice for safety-critical applications. For instance, a dangerous situation which has not been detected by model-based testing might occur in a human-robot co-existence scenario since models do not exactly replicate behaviors of real systems-this problem arises no matter how accurate a model is, since even disturbances and sensor noise can cause a mismatch. We address this issue by adding non-determinism to robotic models and by computing the whole set of possible behaviors using reachability analysis. By using reachset conformance, we automatically adjust the required non-determinism so that all recorded behaviors are captured. For the first time this approach is demonstrated for a real robot.

Mobile robots operating in a shared environment with pedestrians are required to move provably safe to avoid harming pedestrians. Current approaches like safety fields use conservative obstacle models for guaranteeing safety, which leads to degraded performance in populated environments. In this paper, we introduce an online verification approach that uses information about the current pedestrian velocities to compute possible occupancies based on a kinematic model of pedestrian motion. We demonstrate that our method reduces the need for stopping while retaining safety guarantees, and thus goals are reached between 1.4 and 3.5 times faster than the standard ROS navigation stack in the tested scenarios.