Open Access

This paper presents a conceptual sensor design for planar force/torque measurement based on fiber optic sensing. The design includes two rigid bodies, one acting as a reference frame and the other as a force/torque transducer. Both bodies are indirectly connected by prestressed segments of a fiber optic sensor, which act as both structural components and sensing elements to detect changes in their optical path lengths. We derive the non-linear model equations describing the overall deformation state of the sensor when subjected to arbitrary force/torque pairs under static conditions. These equations are solved for three different application scenarios: force sensing, torque sensing, and combined force/torque sensing. We outline the measuring range of the sensor and identify ways of influencing this range. Moreover, we discuss the uniqueness of the mapping between the detected lengths of the optical fiber segments and the applied load. In doing so, we provide a promising simulation-based proof of concept for the presented sensor design.

Chemical processes can be described by nonlinear differential equations, typically with unknown model parameters. These models can be fitted to experimental data through parameter estimation. The estimated parameters are subject to statistical uncertainties, which depend on the type of experiments and can be calculated and minimized through optimal experimental design before their execution. In this contribution, these optimization problems are formulated, methods for their solution are discussed, and their effectiveness is demonstrated by applying them to a chemical reaction system.

This paper presents a compliant, modular, tendondriven manipulator based on tensegrity joints. The design and motion are inspired by the structure and spiral-like grasping behavior of the seahorse tail. The characteristic prestress of the tensegrity-structure significantly influences its gripping capabilities and can be precisely adjusted. Additionally, the modular design allows for scalability to meet various application and size requirements. Potential applications include, but are not limited to, soft gripping in human-interactive environments, as well as active or passive structures in biomedical engineering solutions.

This paper presents a compliant tensegrity robotic arm design that overcomes limitations related to stiffness variation and cascaded actuation. Due to the special design and actuation strategy, the system offers a large workspace using a small number of actuators and system parts. Key features include intrinsic compliance, enhanced stability in various configurations, and a modular tendon-driven actuation system that facilitates continuous stiffness adjustment for adaptive manipulation tasks. The system’s kinematics and actuation strategy are validated experimentally. Results demonstrate an increased workspace and precise control, offering potential applications in dynamic and human-interactive environments.

The hand is one of the most anatomically complex parts of the human body due to its wide range of independent movements. The multi axial movement space of the hand is based on the wrist joint. An injury in this important body part often requires medical intervention in the form of a hand orthosis, which restricts the movement space of a patient’s hand to prevent further damage to internal bones and ligaments. The hand orthosis in this research project is based on the principle of tensegrity structures, which allows for multi axial movement of the hand, without using conventional joint elements. In addition to the theoretical simulation of this medical device a test stand was developed to investigate the experimental characteristics of the orthosis. By replicating a human hand with an attached orthosis, the test rig enables experimental measurements on joint deflection and basic muscle and wrist forces via a cable-based actuating system. To achieve more precise measurements and improved operability of the test stand, the wiring of the electrical components was optimized, as well as improvements in measurement and control engineering, were implemented.