Frequency Domain Analysis of Nonlinear Series Elastic Actuator via Describing Function

Nonlinear stiffness SEAs (NSEAs) inspired by biological muscles offer promise in achieving adaptable stiffness for assistive robots. While assistive robots are often designed and compared based on torque capability and control bandwidth, NSEAs have not been systematically designed in the frequency domain due to their nonlinearity. The describing function, an analytical concept for nonlinear systems, offers a means to understand their behavior in the frequency domain. This paper introduces a frequency domain analysis of nonlinear series elastic actuators using the describing function method. This framework aims to equip researchers and engineers with tools for improved design and control in assistive robotics.Comment: accepted by 2023 IEEE ROBIO conferenc

LQG/LTR Position Control of an BLDC Motor with Experimental Validation

9th International Conference on Electrical and Electronics Engineering (ELECO) (2015 : Bursa, Turkey)In this paper, position control of a BLDC motor is studied. This position control is LQG/LTR control algorithm. In addition, a system identification approach is used to obtain the nominal plant of BLDC Motor. As a consequence, proposed controller is employed for an experiment. It is done by a real-time target machine

Disturbance/Uncertainty Estimator Based Integral Sliding-Mode Control

A disturbance/uncertainty estimator based integral sliding-mode control approach is introduced. Explicit mathematical expressions for robust stability, performance, and bandwidth requirement are derived. The integral sliding-mode controller is built to satisfy certain industrial criteria. It is integrated into the robustness analysis via its quasi-linear representation. The proposed methodology is experimentally verified on a high-precision gimbal control application. It is seen that the estimator works well and significantly improves performance and robustness in the presence of disturbances and uncertainties

Design of a Flight Stabilizer for Fixed-Wing Aircrafts Using H-infinity Loop Shaping Method

9th International Conference on Electrical and Electronics Engineering (ELECO) (2015 : Bursa, Turkey)Autopilot systems for unmanned aerial vehicles (UAVs) and aircrafts provide flight missions without need of human input and make them more reliable and efficient. The first step of designing an autopilot is a stabilizer mode. Conventional autopilot systems have inner and outer loops. Stabilizer is the inner loop for an autopilot. In this paper designing an aircraft control system ensures good performance and robustness that allows control of roll, pitch and yaw angles will be declared. Aircraft dynamics are used to design the model of the control system in the MATLAB Simulink environment. Using loop shaping method to achieve stable and robust control system will be the strategy. Generated controllers to find the most effective one are embedded in the X-plane which is one of the realistic simulations