Tese: Development of a robust and fault tolerant integrated control system to improve the stability of road vehicles in critical driving scenarios
Aluno(a) : Abel Arrieta CastroOrientador(a): Hans Weber e Georg Rill
Área de Concentração: Mecânica Aplicada
Data: 06/11/2017
Link para tese/dissertação: http://doi.org/10.17771/PUCRio.acad.33168
Resumo: Nowadays, new technologies are pushing the road vehicle limits further. Promising applications, e.g., self-driving cars, require a suitable control system that can maintain the vehicle's stability under autonomous driving and critical scenarios. In most of modern cars, the control systems actuate independently, i.e. there is no coordination or data sharing between them. This approach can produce conflicts between these standalone controllers and thus, no improvements on the vehicle's stability are achieved or even a worse scenario for the driver can be produced. In order to overcome these problems, an integrated approach is developed in this dissertation. This integration, defined in this work as Integrated Control (IC), is done by a coordination of all standalone controllers inside the vehicle, i.e. the Anti-Lock Braking System (ABS), the Electronic Stability Program (ESP) and the Four-Wheel Steering System (4WS). The ABS model was built using an ON-OFF control strategy which includes the hydraulic dynamics. To design the ESP, the simple handling vehicle model was used as a reference behavior. The vehicle's tendency, calculated with the desired and actual yaw rate, is used as input of these system and then, braking a specific wheel, it is possible to retain the vehicle's stability. For the 4WS, a simple feed-forward control strategy is employed where the front steering is used as input. The IC was designed using a simple switch control strategy to coordinate all controllers, i.e., ABS, ESP and 4WS. In order to test the performance of the standalone controllers and the IC system, a fully non-linear and three-dimensional multibody vehicle model was developed. In addition, using this non-linear vehicle mathematical model a vehicle simulation package was created, it is named in this thesis as PyCar. This vehicle model is validated using PyCar and set of experimental data obtained by sensors mounted on a scaled car. Finally, in order to prove the advantages of the IC system over the non-integrated approach, simulations in run-off-road scenarios were performed.