Formal verification of bond graph modelled analogue circuits

Analogue circuits are an increasingly critical component in embedded system designs. Traditionally, simulation is used for verification, but owing to the infinite state space of analogue components, the 100% correctness of a design cannot be guaranteed. Formal methods, based around applying mathematical expressions and reasoning to prove correctness, have been developed to increase the verification confidence level. This study introduces and demonstrates a methodology for formally verifying safety properties of analogue circuits. In the proposed approach, system equations are automatically extracted from a SPICE netlist by means of energy-conservative bond graph models. Verification based on abstract model checking and constraint solving is then applied on the extracted equation models. The authors methodology avoids an exhaustive and time demanding simulation that is normally encountered during analogue circuit verification. To this end, the authors have used a set of tools to implement the proposed verification flow and applied it on tunnel diode, Chua and Colpitts oscillators as case studies

DISEÑO DE OSCILADORES CAÓTICOS DE CHUA EN MATLAB, MULTISIM Y DSP-BUILDER (DESIGN OF A CHAOTIC OSCILLATORS OF CHUA IN MATLAB, MULTISIM AND DSP-BUILDER)

ResumenEste artículo presenta la metodología de diseño del sistema caótico de Chua, en los programas de software Matlab, Multisim y DSP-Builder. La simulación del circuito caótico en Multisim va acompañada del cálculo de cada uno de los componentes electrónicos y las conexiones correspondientes. También se hace uso del software Matlab/Simulink para recrear las ecuaciones diferenciales que representan del sistema de Chua, creando un programa mediante el que se pueden obtener las salidas del sistema, visualizarlas gráficamente y comparar los resultados. De la misma manera se muestran los resultados de la implementación en DSP-FPGA específicamente en un DSP-FPGA Cyclone III Edition de Altera, visualizándose las secuencias y los enrollamientos resultantes en un osciloscopio.Palabras Clave: Caos, DSP-Builder, Matlab, Multisim, Oscilador de Chua. AbstractThis article presents the design methodology of a Chua chaotic system, using the software programs Matlab, Multisim and DSP-Builder. The simulation of the chaotic circuit on Multisim is accompanied by the calculation of each of the electronic components and the corresponding connections. Matlab/Simulink software is also used to represent the differential equations that describe the Chua system, generating a program through the outputs signals can be obtained, graphically visualized and compared the results. In the same way the results of implementation into an DSP-FPGA Cyclone III Edition, Altera, visualizing the output sequences and scrolls.Keywords: Chaos, Chua oscillator, DSP-Builder, Matlab, Multisim