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Yayın A gain-switched self-optimizer for braking controller(John Wiley and Sons Ltd, 2017-06) Dinçmen, ErkinAn emergency braking controller is developed with improved operation characteristics near the maximum friction zone. The methodology is based on self-seeking a-priori unknown optimum operation point to maximize a performance function representing the optimal behavior of the considered dynamic system. Sliding mode with uncertain direction of control vector approach is utilized in the algorithm. An adaptive variable gain is utilized in the algorithm to improve its performance. Via the variable gain, both fast convergence to the a-priori unknown optimum operation point and reduced magnitude of oscillations in the braking moment inputs resulting less aggressive control action are achieved.Yayın An emergency braking controller based on extremum seeking with experimental implementation(Springer Berlin Heidelberg, 2018-03-01) Dinçmen, Erkin; Altınel, TunçAn extremum seeking scheme is developed for maximizing the longitudinal tire forces of the road vehicles during emergency braking situations. If the road condition is known, then a conventional braking controller could generate required braking moment to track the slip set point which belongs to that road condition. However, estimating the road condition is not an easy task and it brings additional computation effort. Rather than that, a self optimization algorithm is presented in this paper without relying on road condition estimation. The developed controller searches optimum operation point for getting maximum friction force. Computer simulations show the effectiveness of the self optimization routine. To validate the real time applicability of the algorithm, an electromechanical braking test system is used for the experiments. Due to the limited measurements from the experimental system, force and moment observers are designed to calculate necessary control inputs for maximizing the friction potential, i.e. the braking force. Via the experimental study, it has been shown that the developed self optimizing controller is fast, accurate, and operable on a real braking system.Yayın Self optimizing ABS control algorithm with application(Institute of Electrical and Electronics Engineers Inc, 2015) Dinçmen, Erkin; Altınel, TunçA self optimizing control algorithm is applied to the ABS control problem where the algorithm accomplishes to maximize friction potential of the tires during braking in unknown road conditions. Simulation studies are conducted to show effectiveness of the controller. The algorithm is also tested in an experimental setup. In order to control a real electromechanical braking system, necessary observers are designed and integrated with the algorithm. Experimental study shows the performance of the control algorithm.Yayın Analysis and design of a resistor-less DC-bus active discharge and dynamic braking scheme using IGBTs in the active region(Institute of Electrical and Electronics Engineers Inc., 2026-04) Sezer, Mustafa Murat; Deshmukh, Akshay Vijayrao; Hava, Ahmet Masum; Akın, BilalDuring shutdowns, emergency conditions, and dynamic braking, fully discharging the dc-bus capacitor or clamping the dc-bus voltage in industrial systems is typically managed using power resistors and additional switches. This conventional approach increases system cost, size, and complexity. This article introduces a compact, cost-effective, resistor-less method for two functions: 1) active discharge and 2) dynamic braking in low-power industrial systems. The proposed technique operates IGBTs in their active region with low gate-emitter voltages ($V_{\text {GE}}$ ), creating high impedance in the discharge path to limit current. For active discharge, a constant-power strategy is implemented using pulse frequency modulation (PFM), where the on-time (t_{\text {on}}$ ) of each pulse is fixed and the pulse frequency is ramped up to accelerate energy dissipation. This approach enables complete discharge of a 600-V dc-bus within 1 s, handled entirely by a single IGBT. The method is validated across three different IGBT vendors, showing consistent results and long-term reliability with no parameter degradation after over 200000 completed discharge cycles. For dynamic braking, the PFM method with fixed pulse frequency enables continuous power dissipation between 50 and 150 W for over 30 min. It effectively replaces conventional internal braking resistors typically rated from 20 to 200 W with resistance values of 5-$120~\Omega $. The system can also tolerate brief overloads up to 50% beyond IGBT current ratings for 10-20 s, providing sufficient time to complete braking without failure, as confirmed by test results. All these benefits are achieved through a simple gate driver modification that supplies partial $V_{\text {GE}}$ levels (3-10 V), eliminating bulky resistors, reducing cost by at least 50%, and saving space-making the solution ideal for high-volume industrial applications.
