Emna Aridhi | Faculté des Sciences de Tunis (original) (raw)
Papers by Emna Aridhi
The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simula... more The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simulation is done in order to make a comparison in an open loop with a pseudo bond graph model, which is designed on 20sim software, and it allows varying the temperature, inside the tank, by acting on the temperatures and the mass flows of the hot and cold water, as well as on the output flow. The experimental results show the effectiveness of the bond graph model. However, it can't act against an abrupt disturbance which can exist during the real-time simulation.
International Journal of Reconfigurable and Embedded Systems (IJRES), 2021
This paper invests in FPGA technology to control the speed of an autonomous car using fuzzy logic... more This paper invests in FPGA technology to control the speed of an autonomous car using fuzzy logic. For that purpose, we propose a co-design based on a novel fuzzy controller IP. It was developed using the hardware language VHDL and driven by the Zynq processor through an SDK software design written in C. The proposed IP acts according to the ambient temperature and the presence or absence of an obstacle and its distance from the car. The partitioning of the co-design tasks divides them into hardware and software parts. The simulation results of the fuzzy IP and those of the complete co-design implementation on a Xilinx Zynq board showed the effectiveness of the proposed controller to meet the target constraints and generate suitable PWM signals. The proposed hardware architecture based on 6-LUT blocks uses 11 times fewer logic resources than other previous similar designs. Also, it can be easily updated when new constraints on the system are to be considered, which makes it suitable...
The chapter presents the recent studies focusing on optimizing the efficiency of airconditioning ... more The chapter presents the recent studies focusing on optimizing the efficiency of airconditioning (AC) systems using solar energy. For this purpose, several advanced AC plants (absorption, adsorption, and desiccant) are designed. Their technology and components are described in this chapter. It also discusses the energy intake of the solar energy use in airconditioning, especially in rural regions where the electricity shortage is frequent, as well as the reduction of the energy costs and the pollution rate. A comparison between solar AC systems and traditional AC systems at the level of the designs, costs, and effectiveness is made at the end of the chapter.
This paper presents a review of recent studies interesting in improving the energy efficiency and... more This paper presents a review of recent studies interesting in improving the energy efficiency and cooling quality of refrigeration systems, especially, household refrigerators, air conditioners, and cold storages. They proposed solutions based on renewables such as solar, geothermal, and natural cold through designing advanced plants. Their overall improvement in energy management could bring savings of up to 95% in appropriate conditions and according to the structure of the refrigeration installation. The paper also gives statistics about the energy consumption of refrigeration systems and the interest of using renewables in this field. Published by AIP Publishing. [http://dx.
This paper proposes a pseudo bond graph model of thermal transfers by natural convection inside a... more This paper proposes a pseudo bond graph model of thermal transfers by natural convection inside a household refrigerator. It has two inputs: the ambient temperature and the temperature at the level of the evaporator wall. The latter assesses the functioning of the compressor cycles. A performance comparison, with the experimental data, was carried out in order to verify the model, in which, real measurements are used to modulate the evaporator temperature source. The simulation results show the effectiveness of the proposed approach.
This paper presents a review of recent studies interesting in improving the energy efficiency and... more This paper presents a review of recent studies interesting in improving the energy efficiency and cooling quality of refrigeration systems, especially, household refrigerators, air conditioners, and cold storages. They proposed solutions based on renewables such as solar, geothermal, and natural cold through designing advanced plants. Their overall improvement in energy management could bring savings of up to 95% in appropriate conditions and according to the structure of the refrigeration installation. The paper also gives statistics about the energy consumption of refrigeration systems and the interest of using renewables in this field.
IREC2015 The Sixth International Renewable Energy Congress, 2015
IEEJ Transactions on Electrical and Electronic Engineering, 2015
This paper presents a study on the use of ice to improve the energy efficiency of a domestic refr... more This paper presents a study on the use of ice to improve the energy efficiency of a domestic refrigerator by applying a pseudo bond graph model that describes the thermal transfers sustained by a quantity of ice introduced inside the cavity of refrigeration. The use of ice resulted in a global energy saving of 4.68%. The effect of ice was found to be more significant during the transitional regime. It reduced the response time to reach the stable average temperature from 15 h to only 3.5 h compared to when not using ice. This achievement did not cost additional electrical power, but rather allowed a saving of electrical energy of 76.73%. However, during the steady state, a reduction in the energy efficiency was noted. An improvement in the cooling by keeping the temperature inside the refrigerator more homogeneous is also proved. The model has two inputs: the outside temperature, and the modulated temperature of the evaporator. This latter determines the functioning of the compressor cycle. The model describes the thermal transfers by natural convection inside the refrigerator. Two experiments were carried out to make a performance comparison and to prove the influence of ice in cooling and energy saving. We used real measurements to modulate the evaporator temperature source in the pseudo bond graph model. The simulation results show the effectiveness of the proposed approach.
IEEJ Transactions on Electrical and Electronic Engineering, 2015
This paper presents a study on the use of ice to improve the energy efficiency of a domestic refr... more This paper presents a study on the use of ice to improve the energy efficiency of a domestic refrigerator by applying a pseudo bond graph model that describes the thermal transfers sustained by a quantity of ice introduced inside the cavity of refrigeration. The use of ice resulted in a global energy saving of 4.68%. The effect of ice was found to be more significant during the transitional regime. It reduced the response time to reach the stable average temperature from 15 h to only 3.5 h compared to when not using ice. This achievement did not cost additional electrical power, but rather allowed a saving of electrical energy of 76.73%. However, during the steady state, a reduction in the energy efficiency was noted. An improvement in the cooling by keeping the temperature inside the refrigerator more homogeneous is also proved. The model has two inputs: the outside temperature, and the modulated temperature of the evaporator. This latter determines the functioning of the compressor cycle. The model describes the thermal transfers by natural convection inside the refrigerator. Two experiments were carried out to make a performance comparison and to prove the influence of ice in cooling and energy saving. We used real measurements to modulate the evaporator temperature source in the pseudo bond graph model. The simulation results show the effectiveness of the proposed approach.
This paper presents a study on the use of ice to improve the energy efficiency of a domestic refr... more This paper presents a study on the use of ice to improve the energy efficiency of a domestic refrigerator by applying a pseudo bond graph model that describes the thermal transfers sustained by a quantity of ice introduced inside the cavity of refrigeration. The use of ice resulted in a global energy saving of 4.68%. The effect of ice was found to be more significant during the transitional regime. It reduced the response time to reach the stable average temperature from 15 h to only 3.5 h compared to when not using ice. This achievement did not cost additional electrical power, but rather allowed a saving of electrical energy of 76.73%. However, during the steady state, a reduction in the energy efficiency was noted. An improvement in the cooling by keeping the temperature inside the refrigerator more homogeneous is also proved. The model has two inputs: the outside temperature, and the modulated temperature of the evaporator. This latter determines the functioning of the compressor cycle. The model describes the thermal transfers by natural convection inside the refrigerator. Two experiments were carried out to make a performance comparison and to prove the influence of ice in cooling and energy saving. We used real measurements to modulate the evaporator temperature source in the pseudo bond graph model. The simulation results show the effectiveness of the proposed approach.
A PI controller and a generalized predictive control strategy of the temperature inside a cavity ... more A PI controller and a generalized predictive control strategy of the temperature inside a cavity of refrigeration are proposed, using Matlab/Simulink environment. The control strategies were applied to a third-order discrete state space system, which computes the internal air temperature according to the temperature at the level of the evaporator exchanger, under the influence of the ambient temperature. The system was obtained by linearization of a pseudo bond graph model of thermal transfers inside the refrigeration cavity. The simulation results were compared to those of the pseudo bond graph model for a classical thermostatic control. The used control strategies allowed an average energy saving of about 70% compared with the conventional on/off controller. The predictive control was more efficient than the PI controller of 23.33 %.
The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simula... more The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simulation is done in order to make a comparison in an open loop with a pseudo bond graph model, which is designed on 20sim software, and it allows varying the temperature, inside the tank, by acting on the temperatures and the mass flows of the hot and cold water, as well as on the output flow. The experimental results show the effectiveness of the bond graph model. However, it can't act against an abrupt disturbance which can exist during the real-time simulation.
The paper presents a pseudo bond graph model of a thermo-hydraulic system which is composed by tw... more The paper presents a pseudo bond graph model of a thermo-hydraulic system which is composed by two warm and cold water pipes, a plastic tank and an evacuation pipe. This model is designed on 20sim software and it allows varying the temperature, inside the tank, by acting on the mass flows of the warm and cold water, as well as on the evacuation pipe. A simulation is done for constant and variable water mass flows to show the efficiency of this bond graph model.
In this paper, we propose an implementation of a synthesizable VHDL program of generalized predic... more In this paper, we propose an implementation of a synthesizable VHDL program of generalized predictive control (GPC) without constraints on a map XC3S700A Xilinx Starter Kit using the Xilinx ISE 10.1 software. The control strategy was applied to a second order state system. The VHDL language was used as a programming tool. Real variables were described with the fixed-point representation to overcome the overflow problems during the computations in the VHDL program. The use of FPGA circuits presents a good choice regarding to the problem of computation time encountered in predictive algorithms. A GPC Matlab program was also implemented in order to make a performance comparison. The simulation results show a good set-point tracking.
The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simula... more The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simulation is done in order to make a comparison in an open loop with a pseudo bond graph model, which is designed on 20sim software, and it allows varying the temperature, inside the tank, by acting on the temperatures and the mass flows of the hot and cold water, as well as on the output flow. The experimental results show the effectiveness of the bond graph model. However, it can't act against an abrupt disturbance which can exist during the real-time simulation.
International Journal of Reconfigurable and Embedded Systems (IJRES), 2021
This paper invests in FPGA technology to control the speed of an autonomous car using fuzzy logic... more This paper invests in FPGA technology to control the speed of an autonomous car using fuzzy logic. For that purpose, we propose a co-design based on a novel fuzzy controller IP. It was developed using the hardware language VHDL and driven by the Zynq processor through an SDK software design written in C. The proposed IP acts according to the ambient temperature and the presence or absence of an obstacle and its distance from the car. The partitioning of the co-design tasks divides them into hardware and software parts. The simulation results of the fuzzy IP and those of the complete co-design implementation on a Xilinx Zynq board showed the effectiveness of the proposed controller to meet the target constraints and generate suitable PWM signals. The proposed hardware architecture based on 6-LUT blocks uses 11 times fewer logic resources than other previous similar designs. Also, it can be easily updated when new constraints on the system are to be considered, which makes it suitable...
The chapter presents the recent studies focusing on optimizing the efficiency of airconditioning ... more The chapter presents the recent studies focusing on optimizing the efficiency of airconditioning (AC) systems using solar energy. For this purpose, several advanced AC plants (absorption, adsorption, and desiccant) are designed. Their technology and components are described in this chapter. It also discusses the energy intake of the solar energy use in airconditioning, especially in rural regions where the electricity shortage is frequent, as well as the reduction of the energy costs and the pollution rate. A comparison between solar AC systems and traditional AC systems at the level of the designs, costs, and effectiveness is made at the end of the chapter.
This paper presents a review of recent studies interesting in improving the energy efficiency and... more This paper presents a review of recent studies interesting in improving the energy efficiency and cooling quality of refrigeration systems, especially, household refrigerators, air conditioners, and cold storages. They proposed solutions based on renewables such as solar, geothermal, and natural cold through designing advanced plants. Their overall improvement in energy management could bring savings of up to 95% in appropriate conditions and according to the structure of the refrigeration installation. The paper also gives statistics about the energy consumption of refrigeration systems and the interest of using renewables in this field. Published by AIP Publishing. [http://dx.
This paper proposes a pseudo bond graph model of thermal transfers by natural convection inside a... more This paper proposes a pseudo bond graph model of thermal transfers by natural convection inside a household refrigerator. It has two inputs: the ambient temperature and the temperature at the level of the evaporator wall. The latter assesses the functioning of the compressor cycles. A performance comparison, with the experimental data, was carried out in order to verify the model, in which, real measurements are used to modulate the evaporator temperature source. The simulation results show the effectiveness of the proposed approach.
This paper presents a review of recent studies interesting in improving the energy efficiency and... more This paper presents a review of recent studies interesting in improving the energy efficiency and cooling quality of refrigeration systems, especially, household refrigerators, air conditioners, and cold storages. They proposed solutions based on renewables such as solar, geothermal, and natural cold through designing advanced plants. Their overall improvement in energy management could bring savings of up to 95% in appropriate conditions and according to the structure of the refrigeration installation. The paper also gives statistics about the energy consumption of refrigeration systems and the interest of using renewables in this field.
IREC2015 The Sixth International Renewable Energy Congress, 2015
IEEJ Transactions on Electrical and Electronic Engineering, 2015
This paper presents a study on the use of ice to improve the energy efficiency of a domestic refr... more This paper presents a study on the use of ice to improve the energy efficiency of a domestic refrigerator by applying a pseudo bond graph model that describes the thermal transfers sustained by a quantity of ice introduced inside the cavity of refrigeration. The use of ice resulted in a global energy saving of 4.68%. The effect of ice was found to be more significant during the transitional regime. It reduced the response time to reach the stable average temperature from 15 h to only 3.5 h compared to when not using ice. This achievement did not cost additional electrical power, but rather allowed a saving of electrical energy of 76.73%. However, during the steady state, a reduction in the energy efficiency was noted. An improvement in the cooling by keeping the temperature inside the refrigerator more homogeneous is also proved. The model has two inputs: the outside temperature, and the modulated temperature of the evaporator. This latter determines the functioning of the compressor cycle. The model describes the thermal transfers by natural convection inside the refrigerator. Two experiments were carried out to make a performance comparison and to prove the influence of ice in cooling and energy saving. We used real measurements to modulate the evaporator temperature source in the pseudo bond graph model. The simulation results show the effectiveness of the proposed approach.
IEEJ Transactions on Electrical and Electronic Engineering, 2015
This paper presents a study on the use of ice to improve the energy efficiency of a domestic refr... more This paper presents a study on the use of ice to improve the energy efficiency of a domestic refrigerator by applying a pseudo bond graph model that describes the thermal transfers sustained by a quantity of ice introduced inside the cavity of refrigeration. The use of ice resulted in a global energy saving of 4.68%. The effect of ice was found to be more significant during the transitional regime. It reduced the response time to reach the stable average temperature from 15 h to only 3.5 h compared to when not using ice. This achievement did not cost additional electrical power, but rather allowed a saving of electrical energy of 76.73%. However, during the steady state, a reduction in the energy efficiency was noted. An improvement in the cooling by keeping the temperature inside the refrigerator more homogeneous is also proved. The model has two inputs: the outside temperature, and the modulated temperature of the evaporator. This latter determines the functioning of the compressor cycle. The model describes the thermal transfers by natural convection inside the refrigerator. Two experiments were carried out to make a performance comparison and to prove the influence of ice in cooling and energy saving. We used real measurements to modulate the evaporator temperature source in the pseudo bond graph model. The simulation results show the effectiveness of the proposed approach.
This paper presents a study on the use of ice to improve the energy efficiency of a domestic refr... more This paper presents a study on the use of ice to improve the energy efficiency of a domestic refrigerator by applying a pseudo bond graph model that describes the thermal transfers sustained by a quantity of ice introduced inside the cavity of refrigeration. The use of ice resulted in a global energy saving of 4.68%. The effect of ice was found to be more significant during the transitional regime. It reduced the response time to reach the stable average temperature from 15 h to only 3.5 h compared to when not using ice. This achievement did not cost additional electrical power, but rather allowed a saving of electrical energy of 76.73%. However, during the steady state, a reduction in the energy efficiency was noted. An improvement in the cooling by keeping the temperature inside the refrigerator more homogeneous is also proved. The model has two inputs: the outside temperature, and the modulated temperature of the evaporator. This latter determines the functioning of the compressor cycle. The model describes the thermal transfers by natural convection inside the refrigerator. Two experiments were carried out to make a performance comparison and to prove the influence of ice in cooling and energy saving. We used real measurements to modulate the evaporator temperature source in the pseudo bond graph model. The simulation results show the effectiveness of the proposed approach.
A PI controller and a generalized predictive control strategy of the temperature inside a cavity ... more A PI controller and a generalized predictive control strategy of the temperature inside a cavity of refrigeration are proposed, using Matlab/Simulink environment. The control strategies were applied to a third-order discrete state space system, which computes the internal air temperature according to the temperature at the level of the evaporator exchanger, under the influence of the ambient temperature. The system was obtained by linearization of a pseudo bond graph model of thermal transfers inside the refrigeration cavity. The simulation results were compared to those of the pseudo bond graph model for a classical thermostatic control. The used control strategies allowed an average energy saving of about 70% compared with the conventional on/off controller. The predictive control was more efficient than the PI controller of 23.33 %.
The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simula... more The paper presents the LabVIEW simulation of water temperature inside a plastic tank. This simulation is done in order to make a comparison in an open loop with a pseudo bond graph model, which is designed on 20sim software, and it allows varying the temperature, inside the tank, by acting on the temperatures and the mass flows of the hot and cold water, as well as on the output flow. The experimental results show the effectiveness of the bond graph model. However, it can't act against an abrupt disturbance which can exist during the real-time simulation.
The paper presents a pseudo bond graph model of a thermo-hydraulic system which is composed by tw... more The paper presents a pseudo bond graph model of a thermo-hydraulic system which is composed by two warm and cold water pipes, a plastic tank and an evacuation pipe. This model is designed on 20sim software and it allows varying the temperature, inside the tank, by acting on the mass flows of the warm and cold water, as well as on the evacuation pipe. A simulation is done for constant and variable water mass flows to show the efficiency of this bond graph model.
In this paper, we propose an implementation of a synthesizable VHDL program of generalized predic... more In this paper, we propose an implementation of a synthesizable VHDL program of generalized predictive control (GPC) without constraints on a map XC3S700A Xilinx Starter Kit using the Xilinx ISE 10.1 software. The control strategy was applied to a second order state system. The VHDL language was used as a programming tool. Real variables were described with the fixed-point representation to overcome the overflow problems during the computations in the VHDL program. The use of FPGA circuits presents a good choice regarding to the problem of computation time encountered in predictive algorithms. A GPC Matlab program was also implemented in order to make a performance comparison. The simulation results show a good set-point tracking.