The Experts below are selected from a list of 6144 Experts worldwide ranked by ideXlab platform

Knut Graichen - One of the best experts on this subject based on the ideXlab platform.

  • Constrained online trajectory planning for nonlinear flat SISO systems using a switched State Variable Filter
    Automatica, 2019
    Co-Authors: Steffen Joos, Matthias Bitzer, Roland Karrelmeyer, Knut Graichen
    Abstract:

    Abstract The problem of constrained Online Trajectory Planning (OTP) for Flatness-based Feedforward Controllers (FFC) is discussed for online tracking problems with a-priori unknown reference signals for the system output. As plant, nonlinear minimum phase Single Input Single Output (SISO) systems with input constraints as well as polytopic constraints on the flat State are assumed. The goal is to achieve both, fast reference tracking and a prioritization-based constraint satisfaction despite avoiding an online optimization. Therefore, the OTP is set up by means of a switched State Variable Filter (SSVF). The switching results from the limitation of the Filter’s highest derivative in accordance to the above requirements and is derived with a piecewise solution of an underlying optimization problem. The paper shows the derivation of the SSVF, discusses necessary stability conditions of the proposed concept, and finally demonstrates the SSVF’s performance by means of a simulation study. A comparison to a respective optimal control problem solution and model predictive controller (MPC) is furthermore provided.

  • Online-trajectory planning for State- and input-constrained linear SISO systems using a switched State Variable Filter
    IFAC-PapersOnLine, 2017
    Co-Authors: Steffen Joos, Matthias Bitzer, Roland Karrelmeyer, Knut Graichen
    Abstract:

    Abstract The problem of online-trajectory generation for flat feedforward controllers of linear single input single output systems with polytopic State and input constraints is discussed for servo-tracking problems, i.e. for a-priori unknown command reference signals. Such problems occur for example in the context of a joystick or gas pedal operation. For the generation of smooth reference trajectories, required for the realization of a flatness-based feedforward controller, a switched State Variable Filter is designed in such a way that an optimal trajectory tracking is realized in accordance to the feasible dynamics in the case of State and input constraints. Therefore, a flatness-based relation is derived such that the highest derivative is linked with the respective constraints. In order to obtain a switching law for the selection of the actual active constraint and the adjustment of the admissible dynamics of the Filter, an optimization problem with respect to the tracking behavior is solved. The performance of the algorithm is finally discussed by means of simulation studies of example systems.

J Busshardt - One of the best experts on this subject based on the ideXlab platform.

  • Great Lakes Symposium on VLSI - A VLSI implementation of a State Variable Filter algorithm
    [1991] Proceedings. First Great Lakes Symposium on VLSI, 1991
    Co-Authors: H -j Herpel, P. Windirsch, J Fuhrer, Manfred Glesner, J Busshardt
    Abstract:

    The authors present a digital signal processor (DSP) architecture whose powerful CPU is optimized to solve a State Variable Filter algorithm, but is not limited to that application. State Variable Filters perform low pass Filtering and generate the derivatives of the Filtered signal. These signals are used in systems for real-time process identification. In order to minimize the number of components, program and data memory, timers, and peripheral control logic are integrated on the DSP chip. Software development for this DSP is supported by an assembler, simulator and high level language compiler. In addition to the presentation of the architecture, a design methodology is introduced which uses rapid prototyping techniques to verify system design and algorithms in their real-time environment. >

  • A VLSI implementation of a State Variable Filter algorithm
    VLSI 1991. Proceedings. First Great Lakes Symposium on, 1991
    Co-Authors: H -j Herpel, P. Windirsch, J Fuhrer, Manfred Glesner, J Busshardt
    Abstract:

    The authors present a digital signal processor (DSP) architecture whose powerful CPU is optimized to solve a State Variable Filter algorithm, but is not limited to that application. State Variable Filters perform low pass Filtering and generate the derivatives of the Filtered signal. These signals are used in systems for real-time process identification. In order to minimize the number of components, program and data memory, timers, and peripheral control logic are integrated on the DSP chip. Software development for this DSP is supported by an assembler, simulator and high level language compiler. In addition to the presentation of the architecture, a design methodology is introduced which uses rapid prototyping techniques to verify system design and algorithms in their real-time environment

J. Choma - One of the best experts on this subject based on the ideXlab platform.

  • Stability of a continuous-time State Variable Filter with ORA-L and current amplifier integrators
    1998 IEEE International Conference on Electronics Circuits and Systems. Surfing the Waves of Science and Technology (Cat. No.98EX196), 1998
    Co-Authors: T. Bakken, J. Choma
    Abstract:

    The stability of a continuous-time State Variable Filter is analyzed using the Routh-Hurwitz criterion. This criterion assesses stability by indicating the number of poles that lie in the right-half plane. The Filter is examined separately with integrators implemented with an ORA-L and a current amplifier. Both amplifier types are characterized by a dominant-pole frequency response, and the stability of each implementation is compared. HSPICE simulations confirm the theoretical analyses, which indicate that the bandwidth of the ORAs and current amplifiers must be much larger than the desired frequency of operation to ensure stability. Since the analyses assume a dominant-pole response, all higher-order poles of the actual amplifier must also be much greater than the unity-gain frequency to minimize excess phase.

  • stability of a continuous time State Variable Filter with op amp and ota c integrators
    Great Lakes Symposium on VLSI, 1998
    Co-Authors: T. Bakken, J. Choma
    Abstract:

    The stability of a continuous-time State Variable Filter is analyzed using the Routh-Hurwitz criterion. This criterion assesses stability by indicating the number of poles that lie in the right-half plane. The Filter is examined separately with integrators implemented with an op-amp and an OTA-C. Both amplifier types are characterized by a dominant-pole frequency response, and the stability of each implementation is compared. HSPICE simulations confirm the theoretical analyses, which indicate that the gain-bandwidth product of the op-amps and the bandwidth of the OTAs must be much larger than the desired frequency of operation to ensure stability. Since the analyses assume a dominant-pole response, all higher-order poles of the actual amplifier must also be much greater than the unity-gain frequency to minimize excess phase.

  • Great Lakes Symposium on VLSI - Stability of a continuous-time State Variable Filter with op-amp and OTA-C integrators
    Proceedings of the 8th Great Lakes Symposium on VLSI (Cat. No.98TB100222), 1998
    Co-Authors: T. Bakken, J. Choma
    Abstract:

    The stability of a continuous-time State Variable Filter is analyzed using the Routh-Hurwitz criterion. This criterion assesses stability by indicating the number of poles that lie in the right-half plane. The Filter is examined separately with integrators implemented with an op-amp and an OTA-C. Both amplifier types are characterized by a dominant-pole frequency response, and the stability of each implementation is compared. HSPICE simulations confirm the theoretical analyses, which indicate that the gain-bandwidth product of the op-amps and the bandwidth of the OTAs must be much larger than the desired frequency of operation to ensure stability. Since the analyses assume a dominant-pole response, all higher-order poles of the actual amplifier must also be much greater than the unity-gain frequency to minimize excess phase.

Vitor Silva - One of the best experts on this subject based on the ideXlab platform.

  • DoCEIS - SiC Multilayer Photonic Structures with Self Optical Bias Amplification
    Technological Innovation for Value Creation, 2012
    Co-Authors: Maria Manuela Almeida Carvalho Vieira, Manuel Augusto Vieira, Paula Louro, Alessandro Fantoni, M. Barata, Vitor Silva
    Abstract:

    Characteristics of tunable wavelength pi’n/pin Filters based on a-SiC:H multilayered stacked cells are studied both experimental and theoretically. Results show that the device combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal. An algorithm to decode the multiplex signal is established. A capacitive active band-pass Filter model is presented and supported by an electrical simulation of the State Variable Filter circuit. Experimental and simulated results show that the device acts as a State Variable Filter. It combines the properties of active high-pass and low-pass Filter sections into a capacitive active band-pass Filter using a changing photo capacitance to control the power delivered to the load.

  • SiC Multilayer Photonic Structures with Self Optical Bias Amplification
    2012
    Co-Authors: Manuela Vieira, Paula Louro, Alessandro Fantoni, M. Barata, Manuel Vieira, Vitor Silva
    Abstract:

    Characteristics of tunable wavelength pi’n/pin Filters based on a-SiC:H multilayered stacked cells are studied both experimental and theoretically. Results show that the device combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal. An algorithm to decode the multiplex signal is established. A capacitive active band-pass Filter model is presented and supported by an electrical simulation of the State Variable Filter circuit. Experimental and simulated results show that the device acts as a State Variable Filter. It combines the properties of active high-pass and low-pass Filter sections into a capacitive active band-pass Filter using a changing photo capacitance to control the power delivered to the load.

Steffen Joos - One of the best experts on this subject based on the ideXlab platform.

  • Constrained online trajectory planning for nonlinear flat SISO systems using a switched State Variable Filter
    Automatica, 2019
    Co-Authors: Steffen Joos, Matthias Bitzer, Roland Karrelmeyer, Knut Graichen
    Abstract:

    Abstract The problem of constrained Online Trajectory Planning (OTP) for Flatness-based Feedforward Controllers (FFC) is discussed for online tracking problems with a-priori unknown reference signals for the system output. As plant, nonlinear minimum phase Single Input Single Output (SISO) systems with input constraints as well as polytopic constraints on the flat State are assumed. The goal is to achieve both, fast reference tracking and a prioritization-based constraint satisfaction despite avoiding an online optimization. Therefore, the OTP is set up by means of a switched State Variable Filter (SSVF). The switching results from the limitation of the Filter’s highest derivative in accordance to the above requirements and is derived with a piecewise solution of an underlying optimization problem. The paper shows the derivation of the SSVF, discusses necessary stability conditions of the proposed concept, and finally demonstrates the SSVF’s performance by means of a simulation study. A comparison to a respective optimal control problem solution and model predictive controller (MPC) is furthermore provided.

  • Online-trajectory planning for State- and input-constrained linear SISO systems using a switched State Variable Filter
    IFAC-PapersOnLine, 2017
    Co-Authors: Steffen Joos, Matthias Bitzer, Roland Karrelmeyer, Knut Graichen
    Abstract:

    Abstract The problem of online-trajectory generation for flat feedforward controllers of linear single input single output systems with polytopic State and input constraints is discussed for servo-tracking problems, i.e. for a-priori unknown command reference signals. Such problems occur for example in the context of a joystick or gas pedal operation. For the generation of smooth reference trajectories, required for the realization of a flatness-based feedforward controller, a switched State Variable Filter is designed in such a way that an optimal trajectory tracking is realized in accordance to the feasible dynamics in the case of State and input constraints. Therefore, a flatness-based relation is derived such that the highest derivative is linked with the respective constraints. In order to obtain a switching law for the selection of the actual active constraint and the adjustment of the admissible dynamics of the Filter, an optimization problem with respect to the tracking behavior is solved. The performance of the algorithm is finally discussed by means of simulation studies of example systems.