Toshio Eisaka

A switched Ethernet protocol for hard real-time embedded system applications

This paper presents a protocol to support traffic for hard real-time applications over non real-time LAN technology, with a switched Ethernet based network concept without any modifications of existing Ethernet hardware. Simulation results demonstrate the proposed Ethernet protocol has better real-time performances, higher bandwidth and a larger data frame, and meets the requirements of reliability for hard real-time systems.

Generalized internal model architecture for gain-scheduled control

A two-degree-of-freedom controller architecture and its design strategy for linear parameter-varying (LPV) systems, where the dependent parameters are assumed to be measurable, are proposed in the generalized internal model control (GIMC) framework. First, coprime factorization and Youla parameterization for LPV systems are introduced based on a parameter-dependent Lyapunov function. Then, the GIMC architecture for linear time-invariant systems is extended to LPV systems with these descriptions. Based on this architecture, good tracking performance and good robustness (disturbance rejection) are compatibly achieved by a nominal controller and a conditional controller, respectively. Furthermore, each controller design problem is formulated in terms of linear matrix inequalities related to each L2-gain performance. Finally, a simple design example is illustrated.

Robust Model Matching design for a two-link inverted pendulum

The Pendubot is one of the challenging experimental examples of underactuated systems. Many researches have been done for swing up control and balance or posture control of the Pendubot. For underactuated systems, complex behavior with model uncertainties makes it difficult to achieve satisfactory control performance without tuning controllers parameters. To tune the parameters of the controller, it is desirable to construct module structure controller. A design method of attachable robust compensators for existing control systems have been proposed and referred to as robust model matching (RMM). In this paper, we apply the RMM to a balance/stabilizing control of a Pendubot. The add-on robust compensators improve the robustness without changing expected property of the existing Pendubot control systems

Industrial hard real-time traffic protocol based on switched Ethernet

This paper presents a simple and efficient switched Ethernet communication protocol for industrial hard real-time applications without modifications of the Ethernet hardware. The network is set up with nodes and switch, and establishes a channel within the nodes. Hard real-time communication management is handled by software added between the Ethernet protocols and the TCP/IP suites, and controls the traffic to bypass the TCP/IP stacks. This makes considerably speed up the traffic, and increase the achievable data frame rate.

Development of an Ethernet protocol for industrial real-time communications

This paper provides an Ethernet protocol to support traffic with industrial real-time applications over non-real-time LAN technology, without loss of generality to use common protocol suites like TCP/IP. Real-time communication is handled in the nodes and the switch, by software added between the network layer and the data link layer. Support for real-time communication is made by dynamically setting up real-time channels.

Comprehensive design of linear control systems and its application to PWM inverters

A comprehensive design scheme of SIMO linear control systems is presented and applied to sinusoidal tracking of PWM inverters. Considering the design scheme, we deal with realizable transfer functions of control systems in general SIMO feedback configuration. As a result, a necessary and sufficient condition for transfer functions of achievable closed-loop maps is obtained. Based on the condition, we introduce a novel design scheme of linear control systems. Compared to conventional design scheme such as ß-parameter approach, the proposed one enables numerical optimization with a prescribed order of controller. Moreover, various multi-objective control requirements can be dealt with step by step in order of precedence. An illustrative example of the proposed design scheme applied to sinusoidal tracking of PWM inverters is investigated.

Youla parameterization and design of takagi-sugeno fuzzy control systems

A method of designing Takagi-Sugeno fuzzy control systems based on the parameterization of quadratically stabilizing controllers is presented. Conception of doubly coprime factorization and Youla parameterization of LTI systems are extended to T-S fuzzy system with respect to quadratic stability. The parameterization of the close-loop systems, which are affine with arbitrary stable Q-parameter, is then described. This description enables the application of the Q-parameter approach to various T-S fuzzy control-systems. Above all, a design scheme of Q to obtain L2-gain performance is clarified.

Support industrial hard real-time traffic with switched ethernet

This paper presents a simple and efficient switched Ethernet communication protocol for industrial hard real-time LAN applications. The network is founded with end nodes and a switch, and hard real-time communication is handled by software added between the Ethernet protocols and the TCP/IP suites. We established a virtual link of the source and destination node by applying admission control based upon the requested QoS, and manages hard real-time traffic to bypass the TCP/IP stacks. This bypassing considerably reduces the dwell time in the nodes, and increases the achievable data frame rate. After the bypassing, hard real-time traffic schedule is executed according to dynamic-priority EDF algorithm. The protocol does not need any modifications in the Ethernet hardware and coexists with TCP/IP suites, therefore, the LAN with the protocol can be connected to any existing Ethernet networks and support both real-time traffic and best-effort traffic. Compared to some conventional hard real-time network protocols, the proposed one has better real-time performances, and meets the requirements of reliability for hard real-time system applications.

A NOVEL CONTROL SYSTEM DESIGN FRAMEWORK AND ITS APPLICATION TO ROBUST STEEL ROLLING

A control system design framework based on characteristic transfer functions is presented and applied to robust control of a tandem cold rolling mill. Compared to conventional design scheme such as Q-parameter approach, the proposed one enables numerical optimization with a prescribed order controller. Moreover, multi-objective control problems can be dealt with stepby-step in order of precedence. Namely, various practical control problems can be flexibly considered based on the scheme. We applied this scheme to gage and tension control of a tandem cold mill rolling. Simulation results described that the proposed scheme offers a potential for improvement compared to conventional Invers Linear Quadratic design.

A framework for integrated design of structural and controller parameters

Integrated design of structure-control combined system enhances overall performance. Classical two-step sequential or iterative designs served as a guide to improve the performance. However, this separate-discipline approach fails to guarantee overall optimality. Recently, simultaneous design methods have been proposed via non-convex numerical optimization of the parameters of both plant and controller. In this paper, we introduce an alternative framework that is suitable to treat simultaneous design of structural and controller parameters.