Mohammad Salah

Nonlinear-Control Strategy for Advanced Vehicle Thermal-Management Systems

Advanced thermal-management systems for internal combustion engines can improve coolant-temperature regulation and servomotor power consumption by better regulating the combustion process with multiple computer-controlled electromechanical components. The traditional thermostat valve, coolant pump, and clutch-driven radiator fan are upgraded with servomotor actuators. When the system components function harmoniously, desired thermal conditions can be accomplished in a power-efficient manner. In this paper, a comprehensive nonlinear-control architecture is proposed for transient-temperature tracking. An experimental system has been fabricated and assembled which features a variable-position smart valve, variable-speed electric water pump, variable-speed electric radiator fan, engine block, and various sensors. In the configured system, the steam-based heat exchanger emulates the heat generated by the engines combustion process. Representative numerical and experimental results are discussed to demonstrate the functionality of the thermal-management system in accurately tracking the prescribed temperature profiles and minimizing electrical power consumption.

A Smart Multiple-Loop Automotive Cooling System—Model, Control, and Experimental Study

The integration of computer-controlled electro-mechanical components in ground vehicle cooling systems can improve coolant temperature regulation and servomotor power consumption. Advanced thermal management systems for internal combustion engines can better regulate the combustion process by harmoniously controlling the cooling systems actuators to obtain desired thermal conditions in a power-efficient manner. In this paper, a comprehensive nonlinear control architecture is proposed for transient temperature tracking in multiple cooling circuits, which builds on single-loop studies. An experimental engine and transmission cooling system have been assembled that feature a variable-position smart thermostat valve, two variable-speed electric pumps, variable-speed electric radiator fan, engine block, transmission, radiator, steam-based heat exchanger, and sensors. Representative experimental results are discussed to demonstrate the functionality of the multiloop thermal management system under normal and elevated ambient temperatures. The presented results clearly show that the proposed robust controller-based thermal management system can accurately track prescribed engine and transmission temperature profiles.

Automotive Thermostat Valve Configurations: Enhanced Warm-Up Performance

The automotive cooling system has unrealized potential to improve internal combustion engine performance through enhanced coolant temperature control and reduced parasitic losses. Advanced automotive thermal management systems use controllable actuators (e.g., smart thermostat valve, variable speed water pump, and electric radiator fan) that must work in harmony to control engine temperature. One important area of cooling system operation is warm-up, during which fluid flow is regulated between the bypass and radiator loops. A fundamental question arises regarding the usefulness of the common thermostat valve. In this paper, four different thermostat configurations were analyzed, with accompanying linear and nonlinear control algorithms, to investigate warm-up behaviors and thermostat valve operations. The configurations considered include factory, two-way valve, three-way valve, and no valve. Representative experimental testing was conducted on a steam-based thermal bench to examine the effectiveness of each valve configuration in the engine cooling system. The results clearly demonstrate that the three-way valve has the best performance as noted by the excellent warm-up time, temperature tracking, and cooling system power consumption.

Multiple UAV navigation with finite sensing zone

A navigation function based path planner is developed in this paper for the navigation of multiple unmanned aerial vehicles (UAVs) in the presence of known stationary obstacles and unknown enemy assets (EAs). Specifically, the motion of UAVs are planned in a centralized fashion. The standard navigation function approach is extended to a multiple navigation strategy with an analytical switch among different cases due to the limited sensing zone of the UAVs. A differentiable controller is proposed based on this navigation function that yields asymptotic convergence. A discussion for avoiding moving EAs is presented

Robust Tracking Control for a Piezoelectric Actuator

In this paper, a hysteresis model-based nonlinear robust controller is developed for a piezoelectric actuator, utilizing a Lyapunov-based stability analysis, which ensures that a desired displacement trajectory is accurately tracked.

Time-Varying Angular Rate Sensing for a MEMS Z-Axis Gyroscope

In this paper, both axes of a z-axis MEMS gyroscope are actively controlled to facilitate time-varying angular rate sensing. An off-line adaptive least-squares estimation strategy is first developed that accurately estimates the unknown model parameters. An estimation analysis is presented which proves that the model parameters are accurately estimated. An online active controller/observer is then developed for time-varying angular rate sensing. For this method, a nonlinear estimator is developed based on a Lyapunov-based analysis, which proves that the time-varying angular rate experienced by the device can be estimated accurately

FUZZY LOGIC CONTROL DESIGN FOR ADVANCED VEHICLE THERMAL MANAGEMENT SYSTEMS

The coolant temperature of internal combustion engines can be regulated effectively by advanced thermal management systems that feature multiple computer controlled servomotor actuators (i.e., a variable position smart valve, variable speed electric water pump, variable speed electric radiator fan). When the components of the advanced thermal management system function harmoniously, desired thermal conditions can be achieved in a power efficient manner. Hence, fuel consumption and emissions are reduced. In this paper, a fuzzy logic control architecture is proposed for transient temperature tracking. A representative numerical simulation is introduced to demonstrate the functionality of the thermal management system in accurately tracking a prescribed temperature profile.

Performance Comparison of Different Power Management Control Strategies for a Hybrid Fuel Cell/Battery Vehicle

Power management systems are one of the most important components in modern hybrid vehicles. They are needed to optimize the operation of the hybrid system components. In this paper, a model for a fuel cell/battery vehicle is developed using PSAT and then tested with four power management control strategies utilizing the driving cycle of Amman city, the capital of Jordan. The main components of the hybrid vehicle are a PEM fuel cell, battery, and a brushless dc motor. PEM fuel cells are popular due to their good start up, high power density, and low operating temperature. The role of the battery in a hybrid system is to boost the system power during start-up and transient events in addition to storing the energy recovered from the braking process. The developed hybrid vehicle model is designed and configured so that it matches the power, acceleration, and maximum speed of a midsized vehicle powered by an internal combustion engine. The proposed control strategies are the thermostat strategy, fuel cell optimized strategy, load following strategy and fuzzy logic strategy. All four control strategies are implemented in simulation utilizing PSAT. The simulation results indicate that the best performance in terms of fuel economy is achieved by the load following control strategy.Copyright

Control of ultrasonic transducers for machining applications

Ultrasonically Assisted Machining (UAM) is an emerging technology that has proven to be very efficient in improving the surface finishing in material machining such as turning, milling, and drilling. Smart material actuators are used in such applications to vibrate the cutting tip while machining, hence, improving the manipulated surface. In order to achieve that, it is required to vibrate the cutting tip at certain frequency with certain amplitude. In fact, controlling the amplitude of these smart actuators is a tedious and difficult task due to the inherent nonlinearities associated with smart materials. In this paper, two control algorithms are proposed; sliding mode controller with high frequency (SMHF) and proportional-integral controller with RMS (PIRMS). Numerical simulations are presented to demonstrate the effectiveness of using the proposed controller. The PIRMS algorithm demonstrates a better performance when compared with the SMHF algorithm.

Hybrid vehicular fuel cell/battery powertrain test bench: design, construction, and performance testing:

The development of hybrid vehicular power systems has been conducted for decades to improve transportation quality mainly in terms of environment pollution and fuel economy. Hence, hybrid electric vehicular systems are considered an attractive and potential solution in the long run to replace conventional combustion engine vehicles. In this paper, a scaled-down vehicular powertrain test bench is designed and constructed utilizing a hybrid fuel cell/battery energy sources. The performance of the proposed test bench is also investigated experimentally to explore the modes of operation for system components under various road conditions. Load-following energy management strategy is implemented experimentally in this hybrid configuration. The concepts that can be learned from such test bench are certainly essential for any future implementation on real full-size vehicles. In this study, it is shown that even though fuel cells have a good energy-to-weight ratio, they have a slow response and that is why they must be combined with other fast-response energy sources like a battery or supercapacitor. The test bench is mainly built to explore the implementation of various energy management strategies and control algorithms without the need to have a real vehicle and an automotive test track. In addition, it is an excellent platform for training highly qualified automotive engineers and university undergraduate students as well as automotive researchers.