Cascade PI Control with Extended Kalman Filtering for BLDC Actuators in Collaborative Robotic Arm

Abstract

In this study, we focused on collaborative robots, or cobots, which operate safely alongside humans in shared spaces. Due to the diverse requirements and challenges posed by different tasks and environments, employing various control modes is crucial for cobots. For instance, tasks may necessitate high accuracy, smooth motion, or force interaction. To address this need, we adopted the cascade control technique, leveraging multiple controllers to enhance performance and flexibility. The proposed control logic enables simultaneous and independent regulation of the position, velocity, and current of the actuator. This approach facilitates seamless switching between control modes based on task demands, allowing precise regulation of position, velocity, and current to desired levels. Both the design of the actuator and the control logic were rigorously simulated and evaluated using MATLAB software. To enhance realism, the simulations integrated noise in speed control mode, and the resultant data underwent filtration utilizing an Extended Kalman Filter. The simulation outcomes demonstrate that the actuator's response time meets the required specifications within the targeted timeframe. Overall, our study highlights the effectiveness of cascade control in enabling cobots to adapt to various task requirements and environments, ensuring precise and efficient operation in shared spaces alongside humans.