Soft robots based on particle jamming cannot return to the initial position and initial mechanical state due to the accumulation of particles after removing the particle jamming, which means poor restorability, and the compliance of the robots during deformation will be reduced because of the jamming effect. Here, we present the design, fabrication, and tests of a novel soft actuator with good restorability and compliance. To improve the restorability of the actuator, we used cotton threads to connect the spherical acrylic beads into form strings instead of discrete beads. The beads could be pulled to the initial position by the threads, the actuator also returns to the initial state. To avoid the jamming effect during the deformation of the actuator, we used compressed air to drive the actuator and injected the beads into the actuator after the active deformation. To reduce the driving pressure and facilitate the flow of the beads, an initial noncontact, frame-type strain constraint structure was designed for the soft actuator. Experimental data show that the actuator was flexible during bending and the stiffness can increase more than 12-fold to resist the external load. By pulling the threads, the actuator could be restored to the initial state with an error of less than 3% of the actuator length after an operation cycle. The soft gripper based on the actuator can grasp repeatedly or laterally. The gripper can grasp soft objects such as a piece of tofu and a balloon of water, and the maximum weight that can be stably grasped is 2.744 kg.

We propose a model-driven development approach for autonomous control systems with emphasis on the physical space and the communication via wireless connections. In particular, we combine model-based engineering with simulation and emulation techniques for mobile communication. The design and implementation is done using our Reactive Blocks Framework. For the mobile communication we use the popular IEEE 802.11 WLAN protocol which is simulated using software tools in order to get estimations of connection delays. The spatial constraints are verified with our Be Spaced tool. As an example, we present the design and verification of autonomous robots performing services in a large factory hall and coordinating by means of wireless communication which is based on several access points.

SPACE is a model-driven engineering technique for reactive distributed systems. It enables to develop system models from reusable building blocks, formal analysis by model checking as well as automated transformation to executable code. In this paper, we describe an extension of the SPACE formalism which allows to model and verify also real-time behavior. In particular, one specifies real-time constraints in the interface descriptions of the building blocks, so-called Real-Time External State-Machines (RTESMs). The RTESMs are translated to guards, clocks and invariants of Timed Automata which can be analyzed by means of the model checker UPPAAL. The approach is explained by a component protecting an electrical motor controller system against overspeed. In particular, we prove that by keeping certain maximum response times, this system guarantees that the speed of the motor stays within certain limits.