Browsing by Author "Guvenc, Bilin Aksun"

Now showing 1 - 7 of 7

Citation Count: 0
Communication Disturbance Observer Approach to Control of Integral Plant with Time Delay
(Ieee, 2013) Emirler, Mumin Tolga; Guvenc, Bilin Aksun; Guvenc, Levent
The presence of time delay can cause stability problems in closed loop systems as it adds large negative phase angle to the system frequency response. The Smith predictor is a well-known method of dealing with fixed and known time delays in control systems. Errors in the knowledge of the time delay will cause degradation of the Smith predictor compensation performance. A solution to this problem is to use a communication disturbance observer. Time delayed integral plants are typical examples of open loop unstable systems with time delay. In this paper, the communication disturbance observer based time delay compensation method is applied to high order time delayed integral plants. A robust stability condition is derived for time delayed feedback control systems with the communication disturbance observer. The effect of the communication disturbance observer Q filter cut-off frequency selection on robust stability is investigated. Simulation results are presented for both constant and time varying delays to illustrate the effectiveness of the proposed communication disturbance observer approach.
Citation Count: 38
A control strategy for parallel hybrid electric vehicles based on extremum seeking
(Taylor & Francis Ltd, 2012) Dincmen, Erkin; Guvenc, Bilin Aksun
An energy management control strategy for a parallel hybrid electric vehicle based on the extremum-seeking method for splitting torque between the internal combustion engine and electric motor is proposed in this paper. The control strategy has two levels of operation: the upper and lower levels. The upper level decision-making controller chooses the vehicle operation mode such as the simultaneous use of the internal combustion engine and electric motor, use of only the electric motor, use of only the internal combustion engine, or regenerative braking. In the simultaneous use of the internal combustion engine and electric motor, the optimum energy distribution between these two sources of energy is determined via the extremum-seeking algorithm that searches for maximum drivetrain efficiency. A dynamic programming solution is also obtained and used to form a benchmark for performance evaluation of the proposed method based on extremum seeking. Detailed simulations using a realistic model are presented to illustrate the effectiveness of the methodology.
Citation Count: 25
Design and Evaluation of Robust Cooperative Adaptive Cruise Control Systems in Parameter Space
(Korean Soc Automotive Engineers-ksae, 2018) Emirler, Mumin Tolga; Guvenc, Levent; Guvenc, Bilin Aksun
This paper is on the design of cooperative adaptive cruise control systems for automated driving of platoons of vehicles in the longitudinal direction. Longitudinal models of vehicles with simple dynamics, an uncertain first order time constant and vehicle to vehicle communication with a communication delay are used in the vehicle modeling. A robust parameter space approach is developed and applied to the design of the cooperative adaptive cruise control system. D-stability is chosen as the robust performance goal and the feedback PD controller is designed in controller parameter space to achieve this D-stability goal for a range of possible longitudinal dynamics time constants and different values of time gap. Preceding vehicle acceleration is sent to the ego vehicle using vehicle to vehicle communication and a feedforward controller is used in this inter-vehicle loop to improve performance. Simulation results of an eight vehicle platoon of heterogeneous vehicles are presented and evaluated to demonstrate the efficiency of the proposed design method. Also, the proposed method is compared with a benchmark controller and the feedback only controller. Time gap regulation and string stability are used to assess performance and the effect of the vehicle to vehicle communication frequency on control system performance is also investigated.
Citation Count: 81
Extremum-Seeking Control of ABS Braking in Road Vehicles With Lateral Force Improvement
(Ieee-inst Electrical Electronics Engineers inc, 2014) Dincmen, Erkin; Guvenc, Bilin Aksun; Acarman, Tankut
An ABS control algorithm based on extremum seeking is presented in this brief. The optimum slip ratio between the tire patch and the road is searched online without having to estimate road friction conditions. This is achieved by adapting the extremum-seeking algorithm as a self-optimization routine that seeks the peak point of the tire force-slip curve. As an additional novelty, the proposed algorithm incorporates driver steering input into the optimization procedure to determine the operating region of the tires on the "tire force"-"slip ratio" characteristic-curve. The algorithm operates the tires near the peak point of the force-slip curve during straight line braking. When the driver demands lateral motion in addition to braking, the operating regions of the tires are modified automatically, for improving the lateral stability of the vehicle by increasing the tire lateral forces. A validated, full vehicle model is presented and used in a simulation study to demonstrate the effectiveness of the proposed approach. Simulation results show the benefits of the proposed ABS controller.
Citation Count: 3
Multi-objective parameter space approach based controller and add-on disturbance observer design
(Korean Soc Mechanical Engineers, 2017) Emirler, Mumin Tolga; Guvenc, Bilin Aksun
The parameter space approach based robust PI control design methodology for DC motor speed control is proposed in this paper. The multi-objective design requirements like D-stability, phase margin and mixed sensitivity ( frequency domain) bounds are mapped into the controller parameter space to determine PI controller coefficients which satisfies the desired user-defined specifications. Besides robust PI controller, an add-on disturbance observer is utilized to enhance the tracking performance and disturbance rejection of the control system. The proposed control scheme is validated by simulations and experiments. The results prove that the effectiveness of the proposed control system against uncertainties in the modeling and disturbances on the system response.
Citation Count: 0
Robust Control of Atomic Force Microscopy
(Iste Ltd, 2011) Guvenc, Bilin Aksun; Necipoglu, Serkan; Demirel, Burak; Guvenc, Levent
[No Abstract Available]
Citation Count: 4
Vehicle dynamics modelling and validation for hardware-in-the-loop testing of electronic stability control
(inderscience Enterprises Ltd, 2016) Emirler, Mumin Tolga; Uygan, Ismail Meric Can; Gelbal, Sukru Yaren; Gozu, Murat; Boke, Tevfik Ali; Guvenc, Bilin Aksun; Guvenc, Levent
Hardware-in-the-loop (HiL) simulation is used to test code changes in automotive control systems for component tests and for fault testing. A realistic and validated vehicle dynamic model needs to be used in the simulations. The experimental and simulated results should exhibit a close match in a validation study. The development of a validated CarSim model of a light commercial vehicle for use in HiL simulation is presented in this paper. A CarSim dynamics model has been prepared for a light commercial vehicle and validated using driving test data obtained on a test track. The HiL simulator developed for testing the electronic stability control unit of this vehicle is presented along with results of an exemplary HiL simulation.