Control of a coupled tank system using PI controller with advanced control methods

The liquid level control in tanks and flow control between cascaded or coupled tanks are the basic control problems exist in process industries nowadays. Liquids are to be pumped, stored or mixed in tanks for various types of chemical processes and all these require essential control and regulation of flow and liquid level. In this paper, different types of tuning methods are proposed for Proportional-Integral (PI) controller and are further improved with integration of Advanced Process Control (APC) method such as feedforward and gain scheduling to essentially control the liquid level in Tank 2 of a coupled tank system. The MATLAB/Simulink tools are used to design PI controller using pole-placement, Ciancone, Cohen Coon and modified Ziegler-Nichols tuning method with Cohen Coon tuning method found to have a better performance. Advanced process control such as feedforward-plus-PI, Gain Scheduling (GS) based PI, Internal Model Control (IMC) based PI, feedforward-plus-GS-based PI and feedforward-plus-IMC-based PI controllers are further tested as improvement version to further compare the significance of the advanced process control outcomes hence GS-PI, improved GI-base PI-plus FF found to have better performance. The GS method is built over five operating points to approximate the system’s nonlinearity and is eventually combined with feedforward control to yield a much better performance

Fuel consumption at signalized intersections: Investigating the impact of different signal indication settings

The fuel consumption of vehicles depends on various factors including vehicle design, driving style, traffic management, and road design. Many manufacturers have been developing efficient and smart vehicles, which contributes to minimizing vehicle fuel consumption. However, traffic management and control could restrict the efficiency of having a sustainable mobility system. Intersections are considered as critical locations, in terms of fuel consumption, due to the significant impact of traffic control at these locations on the vehicle maneuver either by stopping or acceleration to clear these bottleneck points. Analyzing the effect of different intersection signal settings is, therefore, important to optimize vehicle fuel consumption. In this study, we used simulator data of sixty-six drivers going through signalized intersections equipped with two different signal indication settings, namely, control and flashing green conditions. We calculated total fuel consumption using the VT-CPFM and COPERT models and then applied GLME with two different model distributions: normal and log-normal to study the correlation between the two treatments and fuel consumption. Results showed that by displaying the remaining green time, flashing green treatment (i.e., signals with traffic light sequence: green, flashing green, yellow and red-green) produced a lower fuel consumption in comparison to control condition (green, yellow and red sequence), yielding to a similar performance of eco-driving. It was found that as drivers become aware ahead of time when the traffic light will be turning red due to the flashing green signal indication, eventually they either speed up a little to cross the intersection in time, or they early start decelerating, which creates a more optimal deceleration pattern. Results also showed that the VT-CPFM model resulted in more realistic results than COPERT due to its ability to capture the transient changes in speed and acceleration.</p