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[Author] Kenji SAWADA(3hit)

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  • Switched Pinning Control for Merging and Splitting Maneuvers of Vehicle Platoons Open Access

    Takuma WAKASA  Yoshiki NAGATANI  Kenji SAWADA  Seiichi SHIN  

     
    PAPER-Systems and Control

      Vol:
    E103-A No:4
      Page(s):
    657-667

    This paper considers a velocity control problem for merging and splitting maneuvers of vehicle platoons. In this paper, an external device sends velocity commands to some vehicles in the platoon, and the others adjust their velocities autonomously. The former is pinning control, and the latter is consensus control in multi-agent control. We propose a switched pinning control algorithm. Our algorithm consists of three sub-methods. The first is an optimal switching method of pinning agents based on an MLD (Mixed Logical Dynamical) system model and MPC (Model Predictive Control). The second is a representation method for dynamical platoon formation with merging and splitting maneuver. The platoon formation follows the positional relation between vehicles or the formation demand from the external device. The third is a switching reduction method by setting a cost function that penalizes the switching of the pinning agents in the steady-state. Our proposed algorithm enables us to improve the consensus speed. Moreover, our algorithm can regroup the platoons to the arbitrary platoons and control the velocities of the multiple vehicle platoons to each target value.

  • Model Based Fallback Control for Networked Control System via Switched Lyapunov Function

    Tsubasa SASAKI  Kenji SAWADA  Seiichi SHIN  Shu HOSOKAWA  

     
    PAPER-Systems and Control

      Vol:
    E100-A No:10
      Page(s):
    2086-2094

    This paper aims to propose a Fallback Control System isolated from cyber-attacks against networked control systems. The fallback control system implements maintaining functionality after an incident. Since cyber-attacks tamper with the communication contents of the networked control systems, the fallback control system is installed in a control target side. The fallback control system detects the incident without the communication contents on field network. This system detects an incident based on a bilinear observer and a switched Lyapunov function. When an incident is detected, normal operation is switched to fallback operation automatically. In this paper, a practical experiment with Ball-Sorter simulating a simple defective discriminator as a part of Factory Automation systems is shown. Assumed cyber-attacks against Ball-Sorter are Man In The Middle attack and Denial of Service attack.

  • Multi-Rate Switched Pinning Control for Velocity Control of Vehicle Platoons Open Access

    Takuma WAKASA  Kenji SAWADA  

     
    PAPER

      Pubricized:
    2021/05/12
      Vol:
    E104-A No:11
      Page(s):
    1461-1469

    This paper proposes a switched pinning control method with a multi-rating mechanism for vehicle platoons. The platoons are expressed as multi-agent systems consisting of mass-damper systems in which pinning agents receive target velocities from external devices (ex. intelligent traffic signals). We construct model predictive control (MPC) algorithm that switches pinning agents via mixed-integer quadratic programmings (MIQP) problems. The optimization rate is determined according to the convergence rate to the target velocities and the inter-vehicular distances. This multi-rating mechanism can reduce the computational load caused by iterative calculation. Numerical results demonstrate that our method has a reduction effect on the string instability by selecting the pinning agents to minimize errors of the inter-vehicular distances to the target distances.