Herman Y. Sutarto

Hybrid Petri net model of a traffic intersection in an urban network

Control in urban traffic networks constitutes an important and challenging research topic nowadays. In the literature, a lot of work can be found devoted to improving the performance of the traffic flow in such systems, by means of controlling the red-to-green switching times of traffic signals. Different techniques have been proposed and commercially implemented, ranging from heuristic methods to model-based optimization. However, given the complexity of the dynamics and the scale of urban traffic networks, there is still a lot of scope for improvement. In this work, a new hybrid model for the traffic behavior at an intersection is introduced. It captures important aspects of the flow dynamics in urban networks. It is shown how this model can be used in order to obtain control strategies that improve the flow of traffic at intersections, leading to the future possibility of controlling several connected intersections in a distributed way.

Compensation of delay time uncertainties on industrial control ethernet networks using LMI based robust H ∞ PID controller

Industrial Ethernet and wireless network become a common platform to implement industrial control in industries. Network control systems are subjected to delay time uncertainties due to the load traffic in the networks. As the PID controller is a major control algorithm in industries, this paper proposes a LMI based robust Hinfin PID controller using robust integral backstepping method to compensate the delay time uncertainties. To design using robust integral backstepping method, the plant and the PID controller are represented as a full state feedback control system in state space representation. The obtained parameters can then be used in the installed PID controller in the network based industrial control systems.

Queue length optimization of vehicles at road intersection using parabolic interpolation method

Traffic congestion has become a serious problem in Indonesia, especially in Jakarta city. The main problem occurs at intersections. One of the solutions that can be proposed to reduce congestion at the intersection is to implement traffic signal control strategy at the intersection. Levels of congestion are determined by the queue length of vehicles. Green time (Tg) and red time (Tr) are determined by the queue length on each of the intersection leg. The lowest congestion level is represented by the smallest value of queue length. Optimization is performed in order to find an optimal value of green time (Tg), such that the queue length of vehicles becomes the smallest in constant cycle time. Due to the cycle time (Tn) is constant and the intersection is controlled in 2 phases, the variable needed to be optimized is only the green time (Tg). The red time (Tr) can then be counted from the cycle time (Tn) minus the green time (Tg).

Some paradigms for coordinating feedback control with applications to urban traffic control and smart grids

This lecture treats the problem of designing local control agents for cooperating components in a network of interacting dynamic systems. Each local control agent must ensure that all local specifications are met, but at the same time must ensure that the different components help each other in achieving good global behavior as well as good local behavior. This problem will be illustrated by using urban traffic control and smart electric power grids as examples. Centralized or hierarchical control approaches are not robust against failures in communication networks, and require unrealistic assumptions on the knowledge of each agent about the overall model. A completely decentralized approach, where each local control agent selfishly tries to achieve its local specifications only, runs a high risk of global interactions that may destabilize the system, making it impossible to achieve the specifications. This talk proposes two paradigms for distributed feedback control that require very little information exchange and very little global model knowledge. The leader/follower control paradigm is illustrated for urban traffic control: heavily loaded leader agents send messages to their follower neighbors requesting that these followers give green only to platoons of vehicles travelling towards the leader intersection at those times when this will be optimal for the performance of the leader. Another coordination paradigm is called the coordinating model predictive control (CMPC). Consider a power transmission network that has been partitioned in interacting regions, where CMPC is used in order to prevent the spread of the disturbances following incidents like line or machine failure. CMPC tries to resolve this by having each local control agent apply a model predictive controller, using as on-line available information not only the local voltage and current measurements, but also information on the planned sequence of future control actions of neighboring agents, communicated to it from time to time. This talk will discuss some of the minimal requirements for modeling, communication and control agent set-up in order to robustly achieve specifications using distributed control.

Robust Integral Backstepping PID using LMI

This paper proposes a technique to find parameters of the PID controller using robust integral backstepping method. The PID controller is basically an output feedback controller for single input single output plant. To design using robust integral backstepping method, the plant and the PID controller are represented as a full state feedback control system in state space representation. In this representation, the PID controller has the same structure to a state feedback law for a plant with an integral at its input. The PID controller then follows the standard procedure in robust control synthesis and the parameters are computed using the LMI method.

Analysis of Controlled Switching Dynamical Systems using Linear Impulsive Dynamical Systems and Invariant Sets

Switching controller for plants with changing modes is a complex problem. Many methods have been developed for this problem. In this paper, the switching controller is designed by using LMI method that will guarantee 2 H type cost. A mini scale helicopter is considered as an example due to its complex dynamic and changing modes operation. The paper specifically investigate the control for transition dynamics between hover and cruise by formulating the phenomena as a hybrid system. State jumps and mode changing of the controller responding to switched of plant dynamics are exploited and discussed. To analysis the dynamic of the controlled linear switching plants with switching controller, a hybrid system representation using linear impulsive differential equation is developed and an invariant set method is used to investigate the property of changing modes and controllers. The transition control performance is demonstrated by SIMULINK and STATEFLOW and compared to that of LQR approach.