Abstract:
A method for controlling a vehicle semi-active suspension system comprising at least one suspension, provides for: detecting vehicle dynamic quantities (S1,S2,...,Sn) during the vehicle ride; on the basis of the detected dynamic quantities, calculating target damping force characteristics (Fam[1:4]) for the at least one suspension of the suspension system (33) suitable to substantially minimize a vehicle body acceleration at the same time substantially maximizing a force transmitted by the at least one suspension to the road surface, said calculating being based on the Sky Hook control model; controlling (34,35,36) the at least one suspension to put the respective damping force characteristics in accordance with the calculated damping force characteristics. A fuzzy calculation is performed to determine, on the basis of the detected dynamic quantities and on a prescribed set of fuzzy rules, the target damping force characteristics.
Abstract:
A method of controlling a flyback DC-DC converter, self-oscillating at steady state conditions, employing a transformer for storing and transferring energy to a load and having an auxiliary winding whose voltage, induced by the current flowing in the secondary winding of the transformer, is monitored to regulate the amount of energy being transferred by way of a primary control loop disabling and enabling the turning on of a power switch driving the primary winding of the transformer and to detect its the zero-crossing and consequently turn on the power switch for a new conduction and energy storage phase, the duration (T ON ) of which is established by a secondary control loop of the output voltage producing the turning off of the power switch for a new off phase (T OFF ), and comprising a fixed frequency oscillator of a frequency lower than the self-oscillating frequency of the converter for start-up charge transient of an output filter capacitor, wherein the power transferred from the primary circuit to the secondary circuit of the flyback transformer is controlled by introducing a delay on the turn-on instant of the power switch in respect to a turn-on command generated, during a self-oscillating functioning phase upon sensing a zero crossing event and during a fixed frequency functioning phase, upon a rising front of the signal generated by said oscillator, in function of input variables of the enabling-disabling primary control loop and of the secondary control loop, regardless of the mode of control.
Abstract:
A circuit implementing a non-integer order dynamic system includes a neural network (1 to 5) adapted to receive at least one input signal (IS) and to generate therefrom at least one output signal (OS). The input and output signals (IS, OS) are related to each by a non-integer order integro-differential relationship through the coefficients of the neural network (1 to 5). A plurality (I, II) of such circuits, implementing respective non-integer order (PI λ D µ ) controllers can be interconnected in an arrangement wherein any of the integral (200) or differential (202) blocks included in one of those circuits generates a signal which is fed to any of the integral (200) or differential (204) blocks of another circuit in the system.
Abstract:
A vehicle comprises at least one semiactive suspension (5) arranged between a vehicle body (2) and a wheel (4) and having a damping coefficient that can be varied in a controlled way by an actuator (14) governed by a control device (18). The control device comprises an accelerometric sensor (15) generating a vehicle body acceleration signal; a potentiometer (16) generating a suspension position signal; a signal conditioning unit (21) for the calculation of the vehicle body speed and the damping speed; a fuzzy control unit (23) which calculates the subsequent position of the actuator on the basis of the vehicle body speed and of the damping speed; and a driving unit (21) which generates a control signal (S1) for the actuator.
Abstract:
The method for authentication and electronic signature is of the private-key, challenge and response type between a user requesting an authorisation (for a specific transaction, or for access to particular resources), via, for example, a smart card (1) and a controller -check terminal (2)-supplying the authorisation. To increase security of the authorisation or authentication operations, the smart card (1) comprises a chaotic generator (23) generating user's acknowledgement code, which is compared with a comparison code generated by the check terminal (2) using a chaotic generator (30) which is the same.