FPGA-based Embedded System Designed for the Deployment in the Compliant Robotic Leg CARL

Abstract

The embedded system that is distributed within a bipedal robot is a key component of such a highly interwoven mechatronic system. Generally, it has to handle two competing main tasks – executing the embedded closed-loop control of the actuators and handling the communication with the higher-level control system. As the restrictions on physical size and energy consumption limit its computational resources, the design of the embedded nodes poses a potential bottleneck for the performance of the overall system. Hence, the following presents an approach to mitigate the conflicting requirements by deploying FPGA-based embedded nodes. It is illustrated how the additional flexibility at the logic level is used to implement the closed-loop force and impedance control of a series elastic actuator. Furthermore, it is shown how the consequent hardware/software co-design enables the deployment of a full featured robotic framework. To validate the concept, the properties of the implementation are characterized.