Digital Implementation via FPGA of Controllers for Active Control of Ground Vehicles

Abstract

This paper studies the implementation issues of a discrete-time super-twisting controller on a field-programmable gate array (FPGA). It is shown how it is possible to enhance this implementation using a pipelining technique. The controller is designed on the basis of a discrete-time vehicle model recently presented. The super-twisting algorithm ensures some robustness properties in the presence of unknown bounded perturbations. It is shown that the pipelined implementation of the super-twisting controller on an FPGA allows lower execution times, and hence, smaller sampling times than its naive implementation. Therefore, the pipelining technique allows the implementation of more sophisticated controllers for vehicle control. Moreover, it is shown that the power consumption of the pipelined control algorithm is lower than a conventional one, which is an important aspect for onboard automobile systems. Since the pipelined implementation of the controller requires shorter times, even if the controller performance is similar to that of the no-pipelined one, the use of pipelining techniques allows the consideration of cheaper FPGAs with less performance. Such results show that the FPGA technology, along with methodological solutions for optimal controller implementation, represents an appealing alternative to electronic control units.