The advancement of digitalization in the manufacturing industry has visualization that enables managers to comprehend the status and operation time of machines, thereby allowing them to identify and address bottlenecks in production lines. Although Gantt charts are commonly used for visualization in the manufacturing industry, there is an increasing need to adopt methods that more effectively visualize past events to facilitate understanding. Consequently, we have developed a Virtual Reality (VR) system aimed at improving the operations of small and medium-sized manufacturing enterprises through visualization. By utilizing sensors installed within the factory, we demonstrated that the VR space facilitates comprehensible work analysis instruction and simulation of optimal work processes.

The autonomous vehicle control system is a typical kind of hybrid system that combines both continuous and discrete behavior.Formal specification and verification techniques help us to verify desired properties of given systems.In this study, we propose a way to describe a formal specification of an autonomous vehicle control system in CafeOBJ algebraic specification language.The control system is a hybrid system with continuous variables of time, velocity, and position controlled by discrete pedal actions including acceleration, braking, and no-operation.We also verify the safety property of the autonomous vehicle control system by a theorem proving technique called the proof score method *

Hybrid systems combine both continuous and discrete behaviors.Formal descriptions of hybrid systems may help us to verify desired properties of a given system formally with computer supports.In this paper, we propose a way to describe a formal specification of a given multitask hybrid system as an observational transition system in CafeOBJ algebraic specification language and verify it by the proof score method based on equational reasoning implemented in CafeOBJ interpreter.

Hybrid systems combine both continuous and discrete behaviors, which occur frequently in safety-critical applications in various domains including Internet-of-Things (IoT) and Cyber-Physical Systems (CPS) applications such as health care, transportation, and robotics. For safe and reliable information society with IoT and CPS technologies, it is important to establish a way to specify and verify hybrid systems formally. Formal descriptions of hybrid systems may help us to verify desired properties of a given system formally with computer supports. We propose a way to describe a formal specification of a given multitask hybrid system as an observational transition system (OTS) in CafeOBJ algebraic specification language. OTSs are models where systems behaviors are described through observations. CafeOBJ supports specification execution based on a rewrite theory. We verify that OTS/CafeOBJ specifications of hybrid systems satisfy desired property by the proof score method based on equational reasoning implemented in CafeOBJ interpreter. In this paper, we specify a signal control system with an arbitrary number of vehicles by our proposed method, and verify the system satisfies a safety property by the proof score method.

This paper describes a procedure to design a passive nonlinear impedance control for port-Hamiltonian systems. By expressing the system with the port-Hamiltonian system, the proposed method can be applied to the nonholonomic system as well as fully actuated mechanical systems. The feedback controller for nonlinear impedance control is acquired by utilizing the results of generalized canonical transformation for port-Hamiltonian system. In addition, we investigate the passivity of the closed loop system and discuss the characteristics of the controlled system. A numerical simulation of two-wheeled vehicle shows the effectiveness of the proposed control method.