Research motivation

The Full Authority Vehicle Control (FAVeC) Project will deliver the control system layer providing full separation of the driver (or, alternatively, an autonomous driving algorithm) from the car in tasks dealing with vehicle dynamics. Such setup is heavily inspired from aerospace, both military and civil applications, where human pilot capabilities are not sufficient in terms of response times, sensorics, and forces needed for actuation. The existing commercial drive by wire systems are commonly limited to mechanical parts substitution by non-intelligent mechatronic sub-systems. This half way solution inherits all disadvantages of fully active actuation (lack of natural force feedback) and drops all desirable benefits (augmentation of driver sensorics, higher bandwidth and precision, possibility to exploit over-actuated vehicle's full potential). Here the proposed FAVeC layer will provide this functionality: the human driver will take the role of mission planner, and the execution will be assured by the smart drive-by-wire system. This solution will serve as a technology enabler for new car concepts, and also for safe and predictable autonomous driving solutions. The functionality of "autopilot" providing autonomous operation is just a tip of iceberg from the control system point of view. Such functionality should be based on a robust control system, with an approved structure, dedicated to stabilization, damping, attitude control and, on top of that, path tracking. Yet current development in autonomous technologies for automotive applications is mainly focused directly and only on this tip of ice berg, omitting these important underlying loops. FAVeC project aims at proper and systematic investigation of such complex vehicle control laws, and at research of model-based robust multi-variable methodologies for their design.

Technology transfer from aerospace

The autopilot term, so often used by autonomous driving community, is well established at the aerospace community, as is the role and importance of flight controls experts and their advanced methodologies for control laws design. The autopilot functionality is functionally supported and relies on complex lower control system layers of Stability and Control Augmentation Systems (SAS, CAS) to provide aircraft or missile stabilization, damping, angular velocities tracking, attitude holds, and finally navigation and path tracking. This methodology is a result of costly and lengthy development process driven by the space-race in the 1950s, moon race in the 1960s, and military air-force technological boom during cold war. This need for advance control solutions gave rise to inherently unstable vehicle configurations, the fly by wire concept, over-actuated systems and advanced multivariable control theory methodologies like H2 optimal control and filtering (e.g. LQR and Kalman filter), robust control system design (Hinf) and more. All this knowledge is nowadays out there, publically available, and tempting to be used in related contexts; advanced full-authority vehicle control is a clear candidate for such research.

Second motivation for aerospace technology transfer are almost shocking similarities and analogies found by comparison of non-linear mathematical models of flight mechanics and vehicle dynamics, types of nonlinearities and characteristics of governing forces and torques acting upon the aerospace vessels and automotive vehicles. For instance, the single-track vehicle lateral dynamics and the aircraft short period approximation models are structurally identical, with the pitching moment curve displaying nearly suspicious similarities to the tire slip curve.

Full-time Full Authority control layer

The most important outcome of the project will be the full authority vehicle control system layer in the form of a proof-of-concept, providing necessary functionality for systematic, reliable and robust transition to the 21st century automotive era, age of autonomous technologies and vehicle platforms enabling the driver to fully exploit super-sport cars with unprecedented manoeuvrability and ride stability combined, e-mobility over-actuated platforms, transportation and utility vehicles with ride-envelope feedback control and safety margins protection systems. Such concept is of a high-risk nature, as automotive industry is quite reluctant to abandon fundamental and glorified principle of driver full authority, partially due to preference of commercial short-term sales-driven development, and potential certification issues. The high gain nature is defined by necessity for such technology in order to fill the gap between autonomous technologies and the low-level vehicle control functionality.

New unorthodox vehicle platforms concepts

A by-product of the full authority vehicle control system layer will be the relaxation of constraints for the vehicle mechanical layout. The traditional concept is dictated by necessary mechanical elements and subsystems defining the driver-centric platform. The full authority vehicle control system layer will however give rise to new concepts where this requirement would no longer be a limiting factor, and in conjunction with advancements in e-motors, battery systems and mechatronics system new unorthodox vehicle systems will be finally possible. Where concepts like modular chassis independent of car body, multi-directional and 360º independent wheel steering system, vehicle platform without driver position definition and relaxed cargo and passenger space optimization. This would serve as technology boom in automotive enabling highly modular solutions, unification and thus the manufacturing cost reduction.

Industrial friendly research results deployment

Standard university level of understanding in the fields of system and control theory and flight controls is typically several years, if not decades, in front of the automotive industry vehicle control expertise. The gap is so significant, that industry often doubles the work in order to "reinvent" the technology and algorithms, which necessarily leads to “reinvention” of dead ends and repetition of costly mistakes. One of the project ambition is to disseminate and establish the role of control system engineer (inspired and motivated by aerospace role of the “flight control system engineer”) in order to prevent such costly attempts.

Page updated

Report abuse