Active Roll Control of Articulated Vehicles

This paper describes an investigation into active roll control of articulated vehicles. The objective is to minimise lateral load transfer using anti-roll bars incorporating low bandwidth hydraulic actuators. Results from handling tests performed on an articulated vehicle are used to validate a nonlinear yaw/roll model of the vehicle. The methodology used to design lateral acceleration controllers for vehicles equipped with active anti-roll bars is developed using a simplified linear articulated vehicle model. The hardware limitations and power consumption requirements of the active elements are studied. The controller is then implemented in the validated articulated vehicle model to evaluate the performance of an articulated lorry with active anti-roll bars. The simulation results demonstrate the possibility of a significant improvement in transient roll performance of the vehicle, using a relatively low power system (10 kW), with low bandwidth actuators (5 Hz).     

主动横向稳定器降低商用车侧倾的研究

将新式主动横向稳定器安装在中型货画的前轴和后轴，通过液压缸与车架连接。本文研究了该稳定器对降低车身侧倾和提高舒适性的效果。仿真分析和实车试验表明，采用前轮转角前馈控制方法，汽车转向时，稳定器产生反侧倾力矩，大幅度地降低车身侧倾。     

Human Control of Road Vehicles

This paper reviews the present state of knowledge of human control of road vehicles. Lateral and longitudinal control of motorcycles and automobiles are discussed, whenever information is available. Although knowledge has increased greatly in the last decade, the major part of this concerns lateral control and most is of an ad hoc nature. Adequate mathematical models for longitudinal motion of the vehicle are yet to be developed. Their development is a necessary step in the attainment of a complete understanding of longitudinal control.     

Human Control of Road Vehicles

SUMMARY

This paper reviews the present state of knowledge of human control of road vehicles. Lateral and longitudinal control of motorcycles and automobiles are discussed, whenever information is available. Although knowledge has increased greatly in the last decade, the major part of this concerns lateral control and most is of an ad hoc nature. Adequate mathematical models for longitudinal motion of the vehicle are yet to be developed. Their development is a necessary step in the attainment of a complete understanding of longitudinal control.     

Active Roll Control for Passenger Cars

The development of a mathematical model of a limited bandwidth hydro-pneumatic suspension that is incorporated into a vehicle handling model is described. The combined model is used to evaluate a suitable control strategy for eliminating body roll during a cornering manoeuvre. The philosophy behind the roll control strategy has been to use feedback measurements of the body motions which do not compromise the ride control. A study of the influence of the position of the body motion feedback transducer on the effectiveness of the system to reduce the body roll is presented. Non-linear modelling of the suspension components for a 0.8g cornering manoeuvre has revealed performance limitations. Conclusions are drawn as to the effectiveness of the control scheme.     

Active Roll Control for Passenger Cars

SUMMARY

The development of a mathematical model of a limited bandwidth hydro-pneumatic suspension that is incorporated into a vehicle handling model is described. The combined model is used to evaluate a suitable control strategy for eliminating body roll during a cornering manoeuvre. The philosophy behind the roll control strategy has been to use feedback measurements of the body motions which do not compromise the ride control. A study of the influence of the position of the body motion feedback transducer on the effectiveness of the system to reduce the body roll is presented. Non-linear modelling of the suspension components for a 0.8g cornering manoeuvre has revealed performance limitations. Conclusions are drawn as to the effectiveness of the control scheme.     

Lateral Control of Commercial Heavy Vehicles

Two nonlinear lateral control algorithms are designed for a tractor-semitrailer type commercial heavy vehicle. The baseline steering control algorithm is designed utilizing input-output linearization. To enhance the lateral stability and furthermore reduce tracking errors of the trailer, braking forces are independently controlled on the inner and outer wheels of the trailer. The coordinated steering and braking control algorithm is designed based on the multivariable backstepping technique. Simulations conducted using the complex model show that the trailer yaw errors under coordinated steering and independent braking force control are much smaller than those without independent braking force control.     

Lateral Control of Commercial Heavy Vehicles

Two nonlinear lateral control algorithms are designed for a tractor-semitrailer type commercial heavy vehicle. The baseline steering control algorithm is designed utilizing input-output linearization. To enhance the lateral stability and furthermore reduce tracking errors of the trailer, braking forces are independently controlled on the inner and outer wheels of the trailer. The coordinated steering and braking control algorithm is designed based on the multivariable backstepping technique. Simulations conducted using the complex model show that the trailer yaw errors under coordinated steering and independent braking force control are much smaller than those without independent braking force control.     

Integrated Control Methodologies for Road Vehicles

Summary This paper considers the scope, methodologies and architectures for the design and development of interacting control systems in road vehicles. The increasing use of electronic controls leads inevitably to an increase in overall system complexity. Given the time and economic constraints of the modern automotive industry, it is not feasible to synthesise and validate the full set of vehicle controls in the form of a unified and centralized controller. On the other hand a fully decentralized approach to control system development and operation will induce performance limitations from un-modelled or unexpected interactions; at worst, such interactions can cause instability and loss of function. There is now increasing pressure to achieve control coordination whilst maintaining a modular approach to the overall system design. With this in mind, the paper provides a framework to review current practice in integrated vehicle control, assesses recent developments in control integration methodologies that are most relevant to the vehicle application, and formulates an enhanced multi-layer architecture that includes explicit coordination functionality. Overall emphasis is placed on the role of control system architecture, the resulting flow of control information and the implications for control system design. An example from handling dynamics is presented, demonstrating the viability of new and flexible approaches. In conclusion a number of outstanding research problems are highlighted.     

Integrated Control Methodologies for Road Vehicles

Summary This paper considers the scope, methodologies and architectures for the design and development of interacting control systems in road vehicles. The increasing use of electronic controls leads inevitably to an increase in overall system complexity. Given the time and economic constraints of the modern automotive industry, it is not feasible to synthesise and validate the full set of vehicle controls in the form of a unified and centralized controller. On the other hand a fully decentralized approach to control system development and operation will induce performance limitations from un-modelled or unexpected interactions; at worst, such interactions can cause instability and loss of function. There is now increasing pressure to achieve control coordination whilst maintaining a modular approach to the overall system design. With this in mind, the paper provides a framework to review current practice in integrated vehicle control, assesses recent developments in control integration methodologies that are most relevant to the vehicle application, and formulates an enhanced multi-layer architecture that includes explicit coordination functionality. Overall emphasis is placed on the role of control system architecture, the resulting flow of control information and the implications for control system design. An example from handling dynamics is presented, demonstrating the viability of new and flexible approaches. In conclusion a number of outstanding research problems are highlighted.     

Fundamental Issues in Suspension Design for Heavy Road Vehicles

Heavy road vehicles play an important role in the economy of many countries by providing an efficient means of transporting freight. Such vehicles can also have a significant impact on safety, the infrastructure and the environment. The design of the suspension affects the performance of the vehicle in terms of ride, infrastructure damage, suspension working space, energy consumption, rollover stability, yaw stability, braking and traction. The published literature on suspension design for heavy road vehicles is reviewed. It is found that extensive knowledge exists, but that there are areas where improved understanding is needed. Areas identified as fundamental issues requiring attention include ride discomfort criteria, secondary suspensions, and controllable suspensions. Two issues in particular are examined in detail: suspension tuning and suspension configuration. In the tuning of suspension parameter values for vibration performance, numerical optimisation techniques have been used extensively, but generic tuning strategies have not been widely developed. Modal analysis is proposed as a technique for gaining the insight into vehicle vibration behaviour necessary to enable tuning strategies to be devised. As an example, the technique is applied to the pitch-plane vibration of a tractor-semitrailer. In analyses of new suspension configurations or concepts, comparison with alternative concepts is not always made. Lack of such comparisons makes the selection of an optimum concept difficult. Analysis of alternative concepts using simple mathematical models, and comparison of their performance using common criteria, is advocated for enabling informed selection of an optimum. An example involving two alternative roll control systems is used to demonstrate the issue.     

Fundamental Issues in Suspension Design for Heavy Road Vehicles

Heavy road vehicles play an important role in the economy of many countries by providing an efficient means of transporting freight. Such vehicles can also have a significant impact on safety, the infrastructure and the environment. The design of the suspension affects the performance of the vehicle in terms of ride, infrastructure damage, suspension working space, energy consumption, rollover stability, yaw stability, braking and traction. The published literature on suspension design for heavy road vehicles is reviewed. It is found that extensive knowledge exists, but that there are areas where improved understanding is needed. Areas identified as fundamental issues requiring attention include ride discomfort criteria, secondary suspensions, and controllable suspensions. Two issues in particular are examined in detail: suspension tuning and suspension configuration. In the tuning of suspension parameter values for vibration performance, numerical optimisation techniques have been used extensively, but generic tuning strategies have not been widely developed. Modal analysis is proposed as a technique for gaining the insight into vehicle vibration behaviour necessary to enable tuning strategies to be devised. As an example, the technique is applied to the pitch-plane vibration of a tractor-semitrailer. In analyses of new suspension configurations or concepts, comparison with alternative concepts is not always made. Lack of such comparisons makes the selection of an optimum concept difficult. Analysis of alternative concepts using simple mathematical models, and comparison of their performance using common criteria, is advocated for enabling informed selection of an optimum. An example involving two alternative roll control systems is used to demonstrate the issue.     

单轴并联式混合动力总成的设计

设计完成了驱动电机与电控共轨柴油机结合而成的混合动力汽车动力总成,该总成用于单轴并联式混合动力汽车。驱动电机既是电驱动装置,又是起动、发电一体化系统(ISG),基于MC 68H9S12DP256B单片机,研制了该总成的控制系统,通过CAN总线实现了联合控制,以电池充放电平衡和发动机燃油经济性为基础,应用了一种模糊逻辑控制策略,实现了混合动力系统的扭矩分配与不同工作模式以及模式间的切换,该总成能够在所要求的工作模式下运转。     

汽车侧倾稳定主动控制系统的仿真研究

在ADAMS/Car下建立了前、后悬架都装有主动横向稳定杆的95自由度虚拟整车模型.采用模糊PID控制策略,在MATLAB/Simulink环境中对车辆抗侧倾性能进行了联合仿真,实现了PID控制过程中参数的在线整定.仿真结果表明,模糊PID控制具有较强的自适应能力和抗干扰能力,可有效减小车身侧倾角,在保证乘坐舒适性的同时提高了车辆的行驶稳定性.     

Roll Dynamics of Commercial Vehicles

An analytical model is developed here for studying the roll dynamics of commercial vehicles. Large displacements and rotations are accounted for in this nonlinear model so that it can be used for the study of roll dynamics well beyond the limits of wheel lift-off. The model is used to illustrate some of the dynamic phenomena in vehicle rollover, especially the interactive coupling between the roll and the vertical modes of motion. The influence of suspension backlash on rollover resistance is demonstrated, and the phenomenon of roll motion resonance is illustrated to suggest new means for evaluating vehicle rollover sensitivity.     

4轮转向车辆主动鲁棒抗侧倾操纵研究

基于4轮转向车辆，提出了一种新的主动抗侧倾方法。这种方法通过主动操纵车辆前后轮转角，就可以实现车辆侧倾控制。设计了鲁棒H∞操纵控制器。仿真表明，通过合理选择加权函数，车辆状态能精确地跟随理想车辆模型，且能有效地抑制侧倾角速度。     

重载运输车侧向调平控制系统研究

结合虚拟样机技术和控制系统仿真技术对自行式重载运输车的自动调平系统进行了设计研究,建立了运输车横向半车多刚体动力学模型,并针对该模型设计了模糊控制器。联合仿真研究结果表明,模糊控制策略能对车架横向倾斜有很好的控制效果。调平精度达到0.17°,调节时间约为1.6s,能够满足调平系统高精度和快速度的要求。     

电动轮汽车主动控制技术

电动轮驱动车辆的驱动主动控制技术是电动车领域一项富有特色的关键技术,文章在综合了大量文献的基础上,分析了电动轮驱动技术的特点,重点对电动轮驱动的主动控制技术中的电子差速技术、驱动防滑技术、动力学控制及参数估算的研究现状和存在的问题进行了分析,最后结合问题提出了未来的研究方向.     

Active Roll Mode Control Implementation on a Narrow Tilting Vehicle

This paper describes work carried out on the development of a narrow tilting vehicle at the University of Minnesota. The project had two objectives. One objective was to better understand the dynamics of two-passenger leaning vehicles. The other was to use this understanding to design and implement leaning control on such a vehicle. The desire was to make a tilting vehicle as easy, in some sense, to drive as a non-leaning vehicle. The scope of this work was fourfold. First, a model of such a system was developed and linearized to obtain a fourth-order linear model. Second, a tilt controller was designed to stabilize a tilting vehicle's unstable rolling mode. Third, the system and controller were simulated using both Simulink and a real time simulator written with Visual Basic. Fourth, and most importantly, an experimental vehicle was built and used for implementation. Comparisons were made between the simulated system and the experimental vehicle. This illustrated the limitations encountered in the simulations but also showed similarities that validated the model. Also, experimental results showed that the vehicle was stabilized well by the controller within the limitations of our hardware.     

Active Dual Mode Tilt Control for Narrow Ground Vehicles

Small, narrow commuter vehicles have attracted considerable interest in recent years as a means to increase the utilization of existing freeways and parking facilities. However, conventional narrow track vehicles are likely to have reduced stability against overturning during hard cornering. A possible solution to this problem lies in vehicles which tilt toward the inside of a turn. Two different ways to achieve this tilt will be analyzed. For direct tilt control (DTC) an actuator forces the upper part of the vehicle to tilt. Steering tilt control (STC) uses steering to control the tilt as is done by motorcycle or bicycle riders. At low speeds, only the DTC system is effective while at high speeds the STC offers less lateral acceleration for the passenger during transient cornering and may seem more natural. The two methods of control will be studied separately and it will be shown that even though the same steady state tilt can be achieved with either system, the transient behavior of the systems is very different. It also will be shown that it is possible to switch from one system to the other at an arbitrarily chosen speed with virtually no transient effects even when the vehicle is not in a steady state. Regardless of which control system is active, the driver simply communicates his desire to follow the road by moving the steering wheel and the control systems take care of the tilting either by using the tilt actuator or by actively steering the road wheels. Thus the driver does not need to leam how to stabilize the tilt mode of the vehicle.