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Michiel Pesgens Bas Vroemen Bart Stouten Frans Veldpaus Maarten Steinbuch 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(5):387-406
Vehicular drivelines with hierarchical powertrain control require good component controller tracking, enabling the main controller to reach the desired goals. This paper focuses on the development of a transmission ratio controller for a hydraulically actuated metal push-belt continuously variable transmission (CVT), using models for the mechanical and the hydraulic part of the CVT. The controller consists of an anti-windup PID feedback part with linearizing weighting and a setpoint feedforward. Physical constraints on the system, especially with respect to the hydraulic pressures, are accounted for using a feedforward part to eliminate their undesired effects on the ratio. The total ratio controller guarantees that one clamping pressure setpoint is minimal, avoiding belt slip, while the other is raised above the minimum level to enable shifting. This approach has potential for improving the efficiency of the CVT, compared to non-model based ratio controllers. Vehicle experiments show that adequate tracking is obtained together with good robustness against actuator saturation. The largest deviations from the ratio setpoint are caused by actuator pressure saturation. It is further revealed that all feedforward and compensator terms in the controller have a beneficial effect on minimizing the tracking error. 相似文献
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为了使机电控制无级变速器(CVT)能够可靠地传递转矩,快速地调节速比,结合某车型的结构性能参数,对机电控制CVT电控电动执行机构的设计方法进行研究。首先,对机电控制CVT电控电动执行机构的结构和工作原理进行分析,说明电控电动执行机构对CVT速比和从动带轮夹紧力的调节方法,从运动学和动力学的角度研究从金属带式无级变速器的传动机理,获得速比与主动带轮可动盘位移的关系以及保证主、从动带轮可靠传递转矩所需要的夹紧力;然后,根据整车的结构性能参数,明确汽车对机电控制CVT的功能需求和性能要求,以电控电动执行机构中直流电动机的负载转矩最小为目标,设计确定各碟形弹簧的参数和组合形式,在此基础上确定电控电动执行机构中电动机械传动系统的结构性能参数;最后,为验证所设计电控电动执行机构参数的正确性,利用所建立的机电控制CVT传动系统模型在ECE工况下对电控电动执行机构的性能进行仿真分析。结果表明:相对传统CVT液压执行机构,在ECE工况下机电控制CVT电控电动执行机构消耗的能量减少52.2%,同时设计的电控电动执行机构在ECE工况下能够实现实际夹紧力和速比对目标值的良好跟随。 相似文献
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A modified CVT ratio map is proposed to obtain the improved fuel economy for a metal belt CVT. Since the CVT system loss,
which occupies most of the drivetrain loss, depends on the engine speed, input torque, primary and secondary actuator pressure,
a modified CVT ratio map is produced to realize the highest engine-CVT overall efficiency through the consideration of CVT
system loss. The modified CVT ratio map is constructed with respect to the demanded vehicle power and present vehicle speed
based on the steady state CVT system loss. Using the modified CVT ratio map, performance simulations are carried out using
the dynamic models of the CVT powertrain. The simulation results indicate that the modified CVT ratio control provides improved
engine-CVT overall system efficiency, and improves the fuel economy of the federal urban driving schedule by 4.9 percent. 相似文献
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S. Kim K. Park H. J. Song Y. K. Hwang S. J. Moon H. S. Ahn M. Tomizuka 《International Journal of Automotive Technology》2012,13(1):87-95
Developed in this research is a control logic for the ARC (Active Roll Control) system that uses rotary-type hydraulic stabilizer
actuators at the front and rear axles. The hydraulic components of the system were modeled in detail using AMESim, and a driving
logic for the hydraulic circuit was constructed based upon the model. The performance of the driving logic was evaluated on
a test bench, and it demonstrated good pressure tracking capability. The control logic was then designed with the target of
reducing the roll motion of the vehicle during cornering. The control logic consists of two parts: a feedforward controller
that generates anti-roll moments in response to the centrifugal force, and a feedback controller that generates anti-roll
moments in order to make the roll angle to follow its target value. The developed ARC logic was evaluated on a test vehicle
under various driving conditions including a slowly accelerated circular motion and a sinusoidal steering. Through the test,
the ARC system demonstrated successful reduction of the roll motion under all conditions, and any discomfort due to the control
delay was not observed even at a fast steering maneuver. 相似文献
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Continuously Variable Transmission (CVT) is one of the most promising automotive transmission technologies because of its
continuously variable gear ratio and reduced shift shock. CVT is different from Manual Transmission and Automatic Transmission,
and it is possible to operate the power source in its high efficiency region with CVT in the drive train. Several types of
CVT exist that can be categorized based on the mechanism of power transmission, such as the belt pulley, traction drive, and
hydrostatic types. This paper investigates the belt pulley CVT, which consists of a thrust actuator, driver pulley, belt,
driven pulley, and preload spring of the output shaft. A complete CVT is constructed, and based on that a simulation program
that analyzes the static performance of a CVT is implemented in Matlab/Simulink. From these simulation results, methods for
improving the efficiency of the CVT are discussed. The coefficient of the torque capacity factor is proposed as affecting
the matching between a power source and a CVT, and methods for improving the matching effect are also investigated. 相似文献
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B. Supriyo K. B. Tawi H. Jamaluddin 《International Journal of Automotive Technology》2013,14(2):313-323
This paper introduces an electro-mechanical, dual acting pulley, continuously variable transmission (EMDAPCVT) and presents its real time ratio controller using a proportional-derivative-plus-conditional-integral (PDPCI) controller. The ratio controller system is developed based on primary (input) and secondary (output) pulley position controllers. Each position controller has two PID parameters, releasing and clamping, which are determined experimentally using a relay feedback method. A PC-based ratio controller system is implemented using Matlab/Simulink® software and a Keithley DAS-1602 data acquisition system card. The experimental results show that the PDPCI controller system can control the CVT ratio adequately. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(9):1247-1268
This paper presents a lateral driver model for vehicle–driver closed-loop simulation at the limits of handling. An appropriate driver model can be used to evaluate the performance of vehicle chassis control systems via computer simulations before vehicle tests which incurs expenses especially at the limits of handling. The driver model consists of two parts. The first part is an upper-level controller employing force-based approach to reduce the number of unknown vehicle parameters. The feedforward part of the upper controller has been designed by using the centre of percussion. The feedback part aims to minimise ‘tangential error’, defined as the sum of body slip angle and yaw error, to match vehicle direction and road heading angle. The part is designed to regenerate an appropriate skid motion similar to that of a professional driver at the limits. The second part is a lower-level controller which converts the desired front lateral force to steering wheel angle. The lower-level controller also consists of feedforward and feedback parts. A two-degree-of-freedom bicycle model-based feedforward part provides nominal steering wheel angle, and the feedback part aims to eliminate unmodelled error. The performance of the lateral driver model has been investigated via computer simulations. It has been shown that the steering behaviours of the proposed driver model are quite close to those of a professional driver at the limits. Compared with the previously developed lateral driver models, the proposed lateral driver model shows good tracking performance at the limits of handling. 相似文献
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This paper presents the road simulator control technology for reproducing a road input signal to implement real road data.
The simulator consists of a hydraulic pump, a servo valve, a hydraulic actuator and its control equipment. QFT (Quantitative
Control Theory) is utilized to control the simulator effectively. The control system illustrates a tracking performance of
the closed-loop controller with a low order transfer function G(s) and a pre-filter F(s) for a parametric uncertainty model. A force controller is designed to communicate the control signal between the simulator
and digital controller. Tracking specification is satisfied with upper and lower bound tolerances on the steep response of
the system to the reference signal. The efficacy of the QFT force controller is verified through the numerical simulation
in which combined dynamics and actuation of the hydraulic servo system are tested. The simulation results show that the proposed
control technique works well under an uncertain hydraulic plant system. The conventional software (Labview) is used to make
up for the real controller on a real-time basis, and the experimental works show that the proposed algorithm works well for
a single road simulator. 相似文献
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压力钢带式无级变速器技术降低油耗的潜能分析(一) 总被引:1,自引:1,他引:0
为降低压力钢带式无级变速(CVT)车型的燃油消耗,将研究重点放在对其内部不同损耗源的分析上,并认为最有可能降低损耗的部分是压力钢带式CVT的变速机构、液压驱动回路及其控制策略。根据研究结果指出,通过采取诸如滑移控制、改进的液压回路、分离离合器或启动-停止控制等措施,压力钢带式CVT仍具有较大的降低油耗的潜力;今后的工作应着重于扩大CVT滑移控制的工作区域及将此功能应用于生产实际中。。 相似文献
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智能电动汽车的发展对制动系统的主动制动和再生制动能力提出了更高的要求。配备真空助力器的传统制动系统难以满足智能电动汽车的需求,因此逐渐被线控制动系统所取代。为提高线控制动系统的集成度与解耦能力,提出了一种新型集成式电液制动系统(Integrated Braking Control System,IBC),能够实现主动制动、再生制动、失效备份等功能。作为机-电-液耦合的高集成度系统,IBC具有复杂的非线性特性和动态摩擦特性,对制动系统压力的精确控制提出了挑战。为了提高IBC制动压力动态控制精度,提出了一种基于集成式电液制动系统的主动制动压力精确控制方法。首先,介绍了IBC的结构原理和控制架构。随后针对液压系统的迟滞特性和传动机构的摩擦特性进行建模与测试。然后基于系统的强非线性特性,提出了主动制动三层闭环级联控制器,其中压力控制层采用液压特性前馈与变增益反馈结合的控制策略,伺服层控制器设计考虑了机构惯性补偿与摩擦补偿,电机控制层采用矢量控制并进行了电压前馈解耦。最后,基于dSPACE设备搭建了硬件在环(Hardware-in-the-loop,HiL)试验台对主动压力控制方法进行验证。结果表明:所提出的压力控制方法能控制制动系统压力快速精确跟随期望压力,使动态压力跟随误差控制在0.4 MPa之内,稳态压力误差控制在0.1 MPa之内。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1687-1704
This paper presents a feedback-feedforward steering controller that simultaneously maintains vehicle stability at the limits of handling while minimising lateral path tracking deviation. The design begins by considering the performance of a baseline controller with a lookahead feedback scheme and a feedforward algorithm based on a nonlinear vehicle handling diagram. While this initial design exhibits desirable stability properties at the limits of handling, the steady-state path deviation increases significantly at highway speeds. Results from both linear and nonlinear analyses indicate that lateral path tracking deviations are minimised when vehicle sideslip is held tangent to the desired path at all times. Analytical results show that directly incorporating this sideslip tangency condition into the steering feedback dramatically improves lateral path tracking, but at the expense of poor closed-loop stability margins. However, incorporating the desired sideslip behaviour into the feedforward loop creates a robust steering controller capable of accurate path tracking and oversteer correction at the physical limits of tyre friction. Experimental data collected from an Audi TTS test vehicle driving at the handling limits on a full length race circuit demonstrates the improved performance of the final controller design. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):671-683
The aim of this research is the optimisation of full-toroidal continuously variable transmission (CVT) in conjunction with the fixed ratio (FR) mechanism, while the optimisation objective is to minimise fuel consumption (FC) of the vehicle in the new European driving cycle. After the dynamic analysis of the power train, a computer model is developed to simulate contact between CVT elements and consequently calculate its efficiency. Then an algorithm is presented to calculate FC of the vehicle in the driving cycle. Then, an optimisation using particle swarm optimisation on the CVT geometry and FR mechanism (which is embedded between CVT and final drive) is carried out to minimise FC. It is found that by utilisation of the optimised CVT; FC will be about 11% and 8% lower, compared with the application of a five-speed manual transmission and conventional CVT, respectively. Finally, effects of the roller tilt angle and oil temperature on the FC are investigated. 相似文献
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Brake systems of the future, including BBW (Brake-by-Wire), are in development in various forms. In one of the proposed hydraulic BBW systems, an electric booster system replaces the pneumatic brake booster with an electric motor and a rotational-to-linear motion mechanism. This system is able to provide improved braking performance by the design of controllers with precise target pressure tracking and control robustness for better system reliability. First, a sliding mode controller is designed using the Lyapunov function approach to secure the robustness of the system against both the model uncertainty and the disturbance caused by the master cylinder and mechanical components. Next, a simulation tool is constructed to validate the electric booster system with the proposed controller. Finally, the electric booster system is implemented into an actual brake ECU and installed in a vehicle for testing under various braking conditions. The experimental results demonstrate that the proposed controller produces faster pressure build-up performance than the conventional brake system, and its tracking performance is sufficient to ensure comfortable braking. 相似文献