Maciej Rosół

Real-time controller design based on NI Compact-RIO

The paper is focused on NI Compact-RIO configured as a controller for the active magnetic levitation used here as a benchmark for time-critical systems. Three real-time configurations: soft, soft with IRQ and hard FPGA are considered. The quality of the real-time control has been tested for each configuration.

Investigation of an energy harvesting MR damper in a vibration control system

In this paper the authors investigate the performance of an energy harvesting MR damper (EH-MRD) employed in a semi-active vibration control system (SVCS) and used in a single DOF mechanical structure configuration. Main components of the newly proposed SCVS include the MR damper and an electromagnetic vibration energy harvester based on the Faradays law (EVEH) that converts vibration energy into electrical energy and delivers electrical power supplying the MR damper. The main objective of the study is to indicate that the SVCS, controlled by the specially designed embedded system, is feasible and presents good performance at the present stage of the research. The work describes investigation the unique features of the EH-MRD, i.e. its self-powering and self-sensing capabilities. Two cases were considered and the testing was done accordingly. In the case 1, only the self-powered capability was investigated. It was found out that harvested energy is sufficient to power the EH-MRD damper and to adjust it to structural vibration. The results confirmed the adequacy of the SVCS and demonstrated a significant reduction of the resonance peak. In the case 2, both the self-powering and self-sensing capabilities were investigated. Due to the self-sensing capability, the SCVS does not require any sensor. It appeared that thus harvested energy is sufficient to power the EH-MRD and enables self-sensing action since the signal of voltage induced by EVEH agrees with the relative velocity signal across the device. Similar to case 1, the resonance peak is significantly reduced.

AUTONOMOUS CONTROL SYSTEM FOR A SQUEEZE MODE MR VIBRATION ISOLATOR IN AN AUTOMOTIVE ENGINE MOUNT

Abstract The investigated autonomous control system for a squeeze mode magnetorheological (MR) vibration isolator is based on an ultra-low power microcontroller MSP430F5529. The design structure of the control system and the dedicated real-time system are briefly presented and the laboratory testing data are summarised.

Time-optimal control for reaction wheel pendulum

A control numerical algorithm solving the timeoptimal problem for the reaction wheel pendulum system, fully effective in the open loop, is examined in the real-time system. There are two control tasks. The first is to transfer the pendulum from the lower to the upper equilibrium point. The second is to transfer the pendulum from the upper to the lower equilibrium point. Both motions are accomplished in the minimal time. Simulated and realtime trajectories are compared. The time-optimal control strategy is concluded.

Velocity estimation for slow motion devices equipped with encoder

This paper addresses the problem of velocity estimation for slow motion elements equipped with encoders. The slow movement causes rare pulses generated from the encoder, rarer than the sampling frequency. In such conditions, the velocity calculation by numeric derivative or Luenbergera observer fails. For that, it is proposed a new velocity estimation algorithm that uses information specific for encoder operating mode. Simulation and real-time experiments have shown a significant reduction in velocity error estimation of the proposed algorithm in comparison to conventional algorithms.

A new current based slip controller for ABS

A laboratory Anti-Lock Brake System (ABS) is examined. The architecture of the ABS system is shown. The real-time experiments related to a control action to stabilize the slip at a certain level are taken into consideration. A new slip control algorithm differs from the previously used approaches. It is based on the measured current of the braking DC motor. The experimental results collected in the real-time for an old (relay) and new (current based) slip control are compared.

Controlled Conditioning System for the Electromagnetic Generator Supporting an MR Damper: Prototyping and Testing

The paper presents the conditioning system prototype intended for an electromagnetic generator supporting an MR damper in self-powered vibration reduction systems. The system engineered in the form of an electronic circuit comprises the following blocks: the MR damper control coil supply, self-powering, measurement and the microcontroller. The self-powering function consists in supplying the microcontroller from the generator, assuming that the voltage is larger than that required to power the microcontroller, otherwise the microcontroller will take up energy from a battery since the system has also the battery charging option. The performance of the system was verified through experiments where it acted as a component of a vibration reduction system.

Cable Vibration Control Supported by SOC Architecture

Abstract In the paper the System-On-the-Chip (SOC) based on a FPGA circuit is presented to collect input data, perform conditioning and to generate the control signals for the cable system equipped with the MR damper. The FPGA configuration and SOC programming techniques are shown. Experimental results of a semi-active vibration control system controlled by the SOC module are considered. A research is conducted how to mitigate or reduce vibrations by control algorithms.

The FPGA technology in control of Electrical Discharge Machining process

Abstract Electrical Discharge Machining (EDM) is very accurate manufacturing process able to trim any desired shapes in various materials. The proposed measurement and control system comprises a stand-alone FPGA controller, EDM machine and data acquisition system (DAQ) based on standard PC. The stand-alone FPGA controller can operate in an open loop and feedback structures. It enables the interaction with a high-speed A/D converters, differential analog D/A converters and digital, differential incremental encoders inputs. In order to demonstrate the performance of a simple controller an experiments in the closed-loop of EDM system were conducted. The real-time control algorithm runs on the autonomous FPGA system which is equipped with a Spartan II chip [7]. The experimental results are shown and discussed. The unique feature of the investigated FPGA-based controller is reaction time which can be shorter than 1 microsecond.

Radio Frequency Measurement and Control Network for a Cable Equipped with the Magnetorheological Damper

The paper is devoted to an investigation of a Radio Frequency (RF) measuring-control system equipped with sensors and actuators distributed along the cable. Displacement, acceleration and strain sensors together with an actuator and PWM type control signals can be used. This system is configured to operate with the experimental setup specially developed to study MR damper performance for vibration suppression of cables. The RF measuring-control system structure, transmission protocol and radio disturbances problem are discussed. The experimental results for the cable laboratory system are presented.