The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper deals with an Optimal Iterative Learning Control approach for the anode pressure during the periodic purge processes of a fuel cell system. Due to accumulation of diffused nitrogen and water condensate inside the anode volume the chemical reaction is restrained. This adverse effect is avoided through the purge process, by which a short time opening of the exhaust valve forces the nitrogen...
This paper deals with an Iterative Learning Control (ILC) approach of the anode pressure during purge processes of a fuel cell (FC) system. The purge processes are necessary because diffused nitrogen and water condensate cumulate in the anode volume and influence the chemical reaction. The temporary opening of the exhaust valve allows the purge process, which removes the water and nitrogen. ILC is...
Sensitive systems in control approaches, such as fuel cells, require exact operating conditions for high efficiency, safety and endurance of the system. A promising method in controlling fuel cell systems is model predictive control (MPC). For those, many states have to be measured very precisely within high sampling rates, because they are used as initial values for the following calculations. However,...
In this paper, an electronic throttle valve system is considered. The mathematical model describing the motion of the valve plate is subject to uncertainties and external disturbances. The throttle plate angle is intended to track given reference profiles. A control scheme consisting of an observer and a state controller, which both are based upon the super-twisting technique, is proposed. Effectiveness...
Polymer electrolyte membrane (PEM) fuel cell systems convert chemical energy from hydrogen into electrical power via a reaction with oxygen. Fuel cells are highly efficient, nearly noiseless, and locally emission-free. However, safe and efficient operation requires special system temperatures, mass flow rates of the reaction gases, and a particular excess ratio and gas pressure on the anode and cathode...
For an efficient chemical reaction and a safe operation for both stationary and dynamic loads all values of anode and cathode gas pressures and stack temperature must fall within specific ranges. System error can result in values outside of these ranges, in turn causing serious damage to the fuel cell (FC). In addition the energy supply by the FC is at risk, because an emergency shutdown is possible...
In this paper a multi-variable control for the simultaneous control of the air temperature and the air humidity of an industrial heating ventilating and air conditioning (HVAC) system is presented. For the multi-input-multi-output (MIMO) control the model predictive control (MPC) method is applied. To model the system local linear neuro fuzzy models (LLNFM) are used and computed by the so-called Local...
This paper focuses on the controller design for heating, ventilating and air conditioning systems. The proposed model based design technique relies on the method of feedback linearization in combination with model predictive control. The design is based on a simplified model derived from thermodynamic equations. The control loop is evaluated in numerical simulation as well as on an industrial real...
In heating, ventilating and air conditioning systems, the presence of undesirable limit cycles is a common problem. This paper outlines the application of the well known describing function method to the analysis and synthesis of a temperature control system used for air-conditioning an office room. PI-controllers are most commonly used in this field of application. In the present case, an existing...
This paper focuses on the supply air temperature control in a complex heating ventilating and air conditioning system. In industrial applications it is a common practice to use standard PI-controllers for temperature control. Typically the controller parameters are either found empirically or by employing standard tuning rules. The present work proposes a systematic approach to tackle the design problem...
In this paper, the control of an electronic throttle valve based on second-order sliding-mode concepts is presented. The so-called twisting algorithm is chosen as the control law. It is shown that the tracking performance for discontinuous reference signals is significantly improved by introducing nonlinear damping by appropriately specifying the sliding surface. The control concept requires the measured...
This paper deals with the design of controllers for electronic throttle valves, which are used in combustion engines for adjusting the air-fuel-ratio. First a simplified model of the throttle valve is presented. Nonlinear phenomena like stick-slip-friction and gear-backlash are neglected. In order to cope with these uncertainties as well with the modelpsilas discontinuous right hand side, concepts...
Higher-order sliding mode concepts eliminate undesired chattering arising in classical variable structure systems. In this paper the control of electronic throttle valves based on second-order sliding mode control is outlined from a practical point of view. First two control strategies, namely the twisting algorithm and the super-twisting algorithm, are tuned by numerical simulations. Then the realtime...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.