Integrated braking control for electric vehicles with in-wheel propulsion and fully decoupled brake-by-wire system

This paper introduces a case study on the potential of new mechatronic chassis systems for battery electric vehicles, in this case a brake-by-wire (BBW) system and in-wheel propulsion on the rear axle combined with an integrated chassis control providing common safety features like anti-lock braking system (ABS), and enhanced functionalities, like torque blending. The presented controller was intended to also show the potential of continuous control strategies with regard to active safety, vehicle stability and driving comfort. Therefore, an integral sliding mode (ISM) and proportional integral (PI) control were used for wheel slip control (WSC) and benchmarked against each other and against classical used rule-based approach. The controller was realized in MatLab/Simulink and tested under real-time conditions in IPG CarMaker simulation environment for experimentally validated models of the target vehicle and its systems. The controller also contains robust observers for estimation of non-measurable vehicle states and parameters e.g., vehicle mass or road grade, which can have a significant influence on control performance and vehicle safety

State of the art of control schemes for smart systems featuring magneto-rheological materials

This review presents various control strategies for application systems utilizing smart magneto-rheological fluid (MRF) and magneto-rheological elastomers (MRE). It is well known that both MRF and MRE are actively studied and applied to many practical systems such as vehicle dampers. The mandatory requirements for successful applications of MRF and MRE include several factors: advanced material properties, optimal mechanisms, suitable modeling, and appropriate control schemes. Among these requirements, the use of an appropriate control scheme is a crucial factor since it is the final action stage of the application systems to achieve the desired output responses. There are numerous different control strategies which have been applied to many different application systems of MRF and MRE, summarized in this review. In the literature review, advantages and disadvantages of each control scheme are discussed so that potential researchers can develop more effective strategies to achieve higher control performance of many application systems utilizing magneto-rheological materials

Smart materials and vehicle efficiency. Design and experimentation of new devices.

In this dissertation the activities carried out during the PhD are comprehensively described. The research mainly focused on the development of novel smart devices aimed at disengaging auxiliaries in internal combustion engine vehicles. In particular, the activities dealt with modeling, design, manufacturing and testing different fail-safe magnetorheological clutch prototypes, in the framework of a project funded by Regione Toscana, which involved two departments of the University of Pisa and Pierburg Pump Technology - Stabilimento di Livorno. After an extended literature review, several concepts of the clutch were proposed, which led to the design of the first magnetorheological prototype. An intensive experimental campaign was conducted, which involved several prototypes. A particular attention was focused on the measurement and analysis of the torque transmitted by the clutch in different operating conditions and new indices were proposed to objectively analyze the performances of magnetorheological clutches in general. On the basis of the results of the first experimental phase, the limits of the first design were analyzed and a novel prototype was developed, which succeeded in fulfilling all the design specifications. Further analyses were carried out in order to develop a clutch model starting from the experimental results. The effect of clutch heating was considered and a complete model of the clutch based on neural networks was proposed. The model was capable of taking into account the effect of the main parameters influencing the torque characteristic and may be used in a vehicle simulator or in a hardware-in-the-loop bench. Finally, an additional component to be connected to the clutch, which made use of shape memory alloys, was developed and tested during the visiting period at the University of Toledo (OH), USA

Robust control of brake systems with decoupled architecture

Modern brake systems have the tendency to decoupled brake system design involving electric and/or electrohydraulic brake actuators. In this thesis, a corresponding brake control architecture applicable for electric and automated vehicles is proposed and includes (i) base braking, (ii) brake blending and (iii) wheel slip control functions. Main focus has been given to the robustness of continuous wheel slip control during emergency braking in high and low road friction conditions. As the solution, several control laws were designed and experimentally validated during road tests. Results obtained for three vehicle prototypes with individual on-board and in-wheel electric motors and electrohydraulic brake-by-wire system present significant improvement in braking performance and ride quality compared to the conventional wheel slip control strategies.Moderne Bremssysteme tendieren zur entkoppelten Konstruktion mit involvierten elektrischen und/oder elektrohydraulischen Aktuatoren. In der vorliegenden Arbeit ist die entsprechende Bremsregelungsarchitektur für die elektrischen und automatisierten Fahrzeuge vorgeschlagen, die beinhaltet Funktionen zur (i) primären Bremsung, (ii) gemischten Bremsung und (iii) Radschlupfregelung. Der Schwerpunkt dieser Arbeit ist auf die Robustheit der kontinuierlichen Radschlupfregelung während einer Notbremsung bei hoher und niedriger Fahrbahnreibung gelegt. Als die Lösung sind mehrere Regelungsstrategien entwickelt und experimentell validiert. Die Ergebnisse für drei Fahrzeugprototypen mit individuellen Board- und Radnabemotoren und einem elektrohydraulischen Brake-by-Wire System demonstrieren wesentliche Verbesserung der Bremsleistung und Fahrqualität im Vergleich zu den konventionellen Strategien der Radschlupfregelung

Intelligent Sliding Mode Scheme for Regenerative Braking Control

Controller design for an Anti-Lock Braking System (ABS) of a Hybrid Electric Vehicle (HEV) or Electric Vehicle (EV) is a challenging task because of the trade-off between braking efficiency and energy recuperation efficiency. In hybrid vehicles, the brake torque demand is met by both the conventional friction braking system and an electric Regenerative Braking System (RBS). Hence, an effective ABS controller is required to achieve high braking efficiency without losing energy recuperation efficiency. This paper presents an Intelligent Sliding Mode Scheme (ISMS) to retain high energy recuperation efficiency as well as good braking efficiency of an EV with a unique braking configuration. The ISMS has a supervisory logic based motor torque limiter and slip controller. The slip controller is designed based on a two-wheeled model which has a hydraulic unit at the front producing frictional braking cooperating with a regenerative braking system with a brake-by-wire unit at the rear wheels. The slip controller is designed considering the hydraulics and motor actuator dynamics and the complete Magic Formula (MF) is used for tyre force estimation. The logic-based torque limiter not only regulates the brake torque to follow an assigned brake force distribution but also ensures that the battery is not overcharged

A Review of Pneumatic Actuators Used for the Design of Medical Simulators and Medical Tools

International audienc

Advanced Mobile Robotics: Volume 3

Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective

Active suspension control of electric vehicle with in-wheel motors

In-wheel motor (IWM) technology has attracted increasing research interests in recent years due to the numerous advantages it offers. However, the direct attachment of IWMs to the wheels can result in an increase in the vehicle unsprung mass and a significant drop in the suspension ride comfort performance and road holding stability. Other issues such as motor bearing wear motor vibration, air-gap eccentricity and residual unbalanced radial force can adversely influence the motor vibration, passenger comfort and vehicle rollover stability. Active suspension and optimized passive suspension are possible methods deployed to improve the ride comfort and safety of electric vehicles equipped with inwheel motor. The trade-off between ride comfort and handling stability is a major challenge in active suspension design. This thesis investigates the development of novel active suspension systems for successful implementation of IWM technology in electric cars. Towards such aim, several active suspension methods based on robust H∞ control methods are developed to achieve enhanced suspension performance by overcoming the conflicting requirement between ride comfort, suspension deflection and road holding. A novel fault-tolerant H∞ controller based on friction compensation is in the presence of system parameter uncertainties, actuator faults, as well as actuator time delay and system friction is proposed. A friction observer-based Takagi-Sugeno (T-S) fuzzy H∞ controller is developed for active suspension with sprung mass variation and system friction. This method is validated experimentally on a quarter car test rig. The experimental results demonstrate the effectiveness of proposed control methods in improving vehicle ride performance and road holding capability under different road profiles. Quarter car suspension model with suspended shaft-less direct-drive motors has the potential to improve the road holding capability and ride performance. Based on the quarter car suspension with dynamic vibration absorber (DVA) model, a multi-objective parameter optimization for active suspension of IWM mounted electric vehicle based on genetic algorithm (GA) is proposed to suppress the sprung mass vibration, motor vibration, motor bearing wear as well as improving ride comfort, suspension deflection and road holding stability. Then a fault-tolerant fuzzy H∞ control design approach for active suspension of IWM driven electric vehicles in the presence of sprung mass variation, actuator faults and control input constraints is proposed. The T-S fuzzy suspension model is used to cope with the possible sprung mass variation. The output feedback control problem for active suspension system of IWM driven electric vehicles with actuator faults and time delay is further investigated. The suspended motor parameters and vehicle suspension parameters are optimized based on the particle swarm optimization. A robust output feedback H∞ controller is designed to guarantee the system’s asymptotic stability and simultaneously satisfying the performance constraints. The proposed output feedback controller reveals much better performance than previous work when different actuator thrust losses and time delay occurs. The road surface roughness is coupled with in-wheel switched reluctance motor air-gap eccentricity and the unbalanced residual vertical force. Coupling effects between road excitation and in wheel switched reluctance motor (SRM) on electric vehicle ride comfort are also analysed in this thesis. A hybrid control method including output feedback controller and SRM controller are designed to suppress SRM vibration and to prolong the SRM lifespan, while at the same time improving vehicle ride comfort. Then a state feedback H∞ controller combined with SRM controller is designed for in-wheel SRM driven electric vehicle with DVA structure to enhance vehicle and SRM performance. Simulation results demonstrate the effectiveness of DVA structure based active suspension system with proposed control method its ability to significantly improve the road holding capability and ride performance, as well as motor performance

Development and verification of a 9-DOF armored vehicle model in the lateral and longitudinal directions

This manuscript presents the development of an armored vehicle model in lateral and longitudinal directions. A Nine Degree of Freedom (9-DOF) armored vehicle model was derived mathematically and integrated with an analytical tire dynamics known as Pacejka Magic Tire model. The armored vehicle model is developed using three main inputs of a vehicle system which are Pitman arm steering system, Powertrain system and also hydraulic assisted brake system. Several testings in lateral and longitudinal direction are performed such as double lane change, slalom, step steer and sudden acceleration and sudden braking to verify the vehicle model. The armored vehicle model is verified using validated software, CarSim, using HMMWV vehicle model as a benchmark. The verification responses show that the developed armored vehicle model can be used for both lateral and longitudinal direction analysis

Self Tuning PID Control Of Antilock Braking System Using Electronic Wedge Brake

This paper describes the design of an antilock braking system (ABS) control for a passenger vehicle that employs an electronic wedge brake (EWB). The system is based on a two-degree-of-freedom (2-DOF) vehicle dynamic traction model, with the EWB acting as the brake actuator. The developed control structure, known as the Self-Tuning PID controller, is made up of a proportional-integral-derivative (PID) controller that serves as the main feedback loop control and a fuzzy supervisory system that serves as a tuner for the PID controller gains. This control structure is generated through two structures, namely FPID and SFPID, where the difference between these two structures is based on the fuzzy input used. An ABS-based PI D controller and a fuzzy fractional PID controller developed in previous works were used as the benchmark, as well as the testing method, to evaluate the effectiveness of the controller structure. According to the results of the tests, the performance of the SFPID controller is better than that of other PID and FPID controllers, being 10% and 1% faster in terms of stopping time, 8% and 1% shorter in terms of stopping distance, 9% and 1% faster in terms of settling time, and 40% and 5% more efficient in reaching the target slip, respectively