Keywords: Adaptive control, Optimization, Mechatronic systems
Abstract: High performance demands on accuracy and system throughput are common in many industrial applications, making well-designed control laws and reference trajectories essential. Yet, while system performance depends on the joint effects of feedforward control, feedback control, and the design of the reference, these different elements of the control system are typically designed sequentially rather than simultaneously. Such a sequential design approach potentially leads to a loss in obtainable performance. In this work, we present a novel unified data-driven co-design framework for feedforward, feedback, and/or reference design. This framework aims at minimizing the duration of the transient phase in setpoint control: the time required to execute a point-to-point task and reach a desired level of accuracy. The efficacy of the proposed approach in minimizing this duration is demonstrated in a case study of an industrial wire bonder system, in which reductions of up to 54% in the duration of the transient phase were obtained compared to the current industrial state-of-practice.

Keywords: Variable structure systems, Robotics applications, PID control
Abstract: This work investigates relay-based methods to reveal the frequency domain characteristics of BlueROV2 underwater vehicle. Two relay-based approaches are examined: the Modified Relay Feedback Test (MRFT) and a two-relay (twisting-type) controller. The distinguishing feature of these relay tests is their ability to capture process frequency-response data at a desired phase angle in the Nyquist plot. Approximate equivalence of these tests is also discussed. Influence of additional dynamics on oscillations for these tests is discussed and it is argued that these relay tests have capability to excite both actuator and plant dynamics simultaneously, hence provide a mean to perform full system identification and precise controller tuning. Experiment and simulations of oscillation tests are also presented.

Keywords: Sliding mode control, Adaptive control, Control Technology
Abstract: Abstract—This paper presents an Adaptive Integral Terminal Sliding Mode Control (AITSMC) strategy for a Steer-by-Wire (SBW) system to improve robustness and steering performance under parameter variations, external disturbances, and changing road conditions. AITSMC incorporates an adaptation mechanism to estimate the self-aligning torque coefficient, allowing real-time compensation for road condition variations. To evaluate its effectiveness, Conventional Sliding Mode Control, Adaptive Sliding Mode Control, and Integral Terminal Sliding Mode Control are also designed and analyzed. A comprehensive comparative study through MATLAB/Simulink simulations demonstrates the superiority of AITSMC in robustness and tracking performance against diverse road conditions as well as parametric uncertainties, which contributes to improve vehicle handling and stability of SBW systems.

Keywords: Control Technology