A highly parallelized control system platform architecture using multicore CPU and FPGA for multi-DoF robots

TitleA highly parallelized control system platform architecture using multicore CPU and FPGA for multi-DoF robots
Publication TypeConference Paper
Year of Publication2014
AuthorsSeok, S., D. Jin Hyun, SI. Park, D.. Otten, and S. Kim
Conference NameRobotics and Automation (ICRA), 2014 IEEE International Conference on
Date PublishedMay
Keywordsbandwidth 120 Hz, bandwidth 400 Hz, control bandwidth, Control systems, distributed local processors, fast locomotive capability, field programmable gate array, field programmable gate arrays, FPGA, frequency 4 kHz, high-force proprioceptive impedance control, highly dynamic robot, highly parallelized control system platform architecture, leg actuation system, locomotion efficiency, MapReduce model, mechanical impedance, MIT Cheetah, multicore CPU, Multicore processing, multidegrees of freedom robots, multiDoF robots, multilayered architecture, multiprocessing systems, parallel processing, parallel real-time computing technologies, pipeline processing, pipelining method, Program processors, robot dynamics, Robot sensing systems

This paper presents a control system platform architecture developed for multi-degrees of freedom (DoFs) robots capable of highly dynamic movements. In robotic applications that require rapid physical interactions with the environment, it is critical for the robot to achieve a high frequency synchronization of data processing from a large number of high-bandwidth actuators and sensors. To address this important problem in robotics, we developed a control system architecture that effectively utilizes the advantages of modern parallel real-time computing technologies: multicore CPU, the Field Programmable Gate Array (FPGA), and distributed local processors. This approach was implemented in the fast running experiments of the MIT Cheetah. In such a highly dynamic robot, the required control bandwidth is particularly high since the MIT Cheetah's leg actuation system is designed to generate high force (output torque up to 100Nm) with high bandwidth (400Hz electrical, 120Hz mechanical) with minimal mechanical impedance for fast locomotive capability. On the integrated control system, a multi-layered architecture is programmed. Inspired by the MapReduce model and the pipelining method, more than 50 processes are operated in parallel, and major processes among them are optimized to achieve the maximum throughput. The proposed architecture enables the control update frequency 4 kHz. With this control system platform, we achieved a high-force proprioceptive impedance control [1], and a trot-running up to 6 m/s with a locomotion efficiency rivaling animals [2]. This control system architecture is well suited for the future trend towards real-time computing system and, thus can be a candidate for a future standard robot control platform.