Development of a New Concept of Electrically Powered Hydraulic Steering

Badawy, Aly; Fehlings, Dieter; Wiertz, Alexander; Gessat, Jochen

doi:10.4271/2004-01-2070

Cited by 12 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, electro-hydraulic power steering systems (EHPSSs) are wildly used in multi-axle vehicles, combining hydraulic power steering and electronic control systems. 4–7…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, electro-hydraulic power steering systems (EHPSSs) are wildly used in multi-axle vehicles, combining hydraulic power steering and electronic control systems. [4][5][6][7] It is difficult to establish an accurate EHPSS model because of its complex structure, including steering mechanisms, valve controlled dual hydraulic actuators, and heavy duty tires. The coupling relationships among these three parts further increase the difficulty of accurate modeling.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling, simulation, and experimental validation of electro-hydraulic power steering system in multi-axle vehicles

Zhang

Chen

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

An accurate electro-hydraulic power steering system (EHPSS) model is essential to analyze dynamic steering performance and advanced nonlinear control. The main obstacle to establish an accurate model is the complex structure, including steering mechanism, valve controlled dual hydraulic-actuator, and heavy duty tires. This paper constructs a suitable model incorporating these parts, based on a Lagrange equation describing the steering trapezoid mechanism and dual cylinder hydraulic dynamics, regarding steering resisting moment as an external load. A simplified tire model is used to represent the tire basic steering load characteristics. Due to the complexity of the kinematic relationship in the model, several expressions are fitted using back propagation neural networks to significantly reduce calculation difficulty. Experimental measurements and simulation using Matlab/Simulink and experiment are realized for the case of in situ steering, and the results validate the proposed model accuracy. Thus, the proposed model is suitable to analyze the system and design advanced controllers.

show abstract

“…Therefore, electro-hydraulic power steering systems (EHPSSs) are wildly used in multi-axle vehicles, combining hydraulic power steering and electronic control systems. 4–7…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modeling, simulation, and experimental validation of electro-hydraulic power steering system in multi-axle vehicles

Zhang

Chen

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

show abstract

“…From the block diagram in Fig. 6, the open loop and closed loop of the pressure response with the servo valves can be derived and are shown in (15) and (16), respectively.…”

Section: B Closed-centre Systemmentioning

confidence: 99%

“…During non-steering, the motor speed is very low since no assistance is needed. A certain degree of motor speed is, however, necessary in many cases to provide assistance without significant lag, [15]. Other advantages of the system include improved packaging and the possibility to vary the level of assistance for different scenarios and in that way to some extent tune the steering feel.…”

Section: Introductionmentioning

confidence: 99%

Modeling, Simulation, and Experimental Investigation of an Electrohydraulic Closed-Center Power Steering System

Dell’Amico

Krus

2015

IEEE/ASME Trans. Mechatron.

View full text Add to dashboard Cite

Abstract-In steering-related active safety systems, active steering is a key component. Active steering refers to the possibility to control the road wheel angle or the required torque to turn the wheels by means of an electronic signal. Due to the high axle loads in heavy vehicles, hydraulic power is needed to assist the driver in turning the wheels. One solution to realise active steering is then to use electronically controlled valves that are of closed-centre type. This means that the assistance pressure, or force, can be set to any feasible value and still benefit from the high power density of fluid power systems. A closed-centre solution also implies that a significant reduction in fuel consumption is possible. This paper investigates such an electrohydraulic power steering system and a comparison with the original system is also made. The findings have shown that while a high response of the pressure control loop is desired for a good steering feel, instability might occur at higher steering wheel torque levels. This has effectively been shown and explained by simulation and hardware-in-the-loop simulation, together with linear analysis. For any desired boost curve, the response of the pressure control loop must be designed to preserve stability over the entire working range.

show abstract

“…If one or the other can be altered by an electric signal, the pressure could be actively controlled. The Electrohydraulic Power Assisted Steering system, EHPAS, which is presented by for example Forbes, Baird, and Weisgerber (1987), Gessat (2007) and Badawy, Fehlings, et al (2004), was primarly designed to overcome the poor energy efficiency of the HPAS system. Intead of driving the pump from the combustion engine directly, an electric motor is used to drive the pump.…”

Section: On Electrohydraulic Pressure Control For Power Steering Applmentioning

confidence: 99%

On Electrohydraulic Pressure Control for Power Steering Applications : Active Steering for Road Vehicles

Dell’Amico¹

2016

View full text Add to dashboard Cite

This thesis deals with the Electrohydraulic Power Steering system for road vehicles, using electronic pressure control valves. With an ever increasing demand for safer vehicles and fewer traffic accidents, steering-related active safety functions are becoming more common in modern vehicles. These are functions that aim at assisting the driver in more or less critical situations and could be anything from applying a guiding steering torque to taking over the steering completely. Future road vehicles will also evolve towards autonomous vehicles, with several safety, environmental and financial benefits. A key component in realising such solutions is active steering. This refers to the possibility to control the steering angle or steering torque with an electronic signal.The power steering system was initially developed to ease the driver's workload by assisting in turning the wheels. This is traditionally done through an open-centre hydraulic system and heavy trucks must still rely on fluid power, due to the heavy work forces. The system provides a robust solution but suffers from poor energy efficiency and lacks the possibility of active control. Since the purpose of the original system is to control the assistive pressure, one way would be to use proportional pressure control valves. Since these are electronically controlled, active steering is possible and with closed-centre, energy efficiency can be significantly improved on.In this work, such a system is analysed in detail with the purpose of investigating the possible use of the system for Boost curve control, the most common control strategy in power steering systems, and position control for autonomous driving. Commercially available valves are investigated since they provide an attractive solution. A model-based approach is adopted, where simulation of the system is an important tool. Detailed models at both a component level and a system level are developed and form the basis of the analysis and control design. Another important tool is hardware-in-the-loop simulation. A test rig of the system, that also includes the original system, is developed. The rig supports the modelling and validation process, as it also makes it possible to verify control concepts on a real system. This work has shown how proportional pressure control valves can be used for Boost curve control and position control and what implications this has i on a system level. As it turns out, the valves add a great deal of phase shift and with the high gain from the Boost curve, this creates a control challenge. The problem can be handled by tuning the Boost gain, pressure response and damping and has been effectively shown through simulation and experiments. For position control, there is greater freedom to design the controller to fit the system. The pressure response can be made fast enough for this case and the phase shift is much less critical.Keywords: Electrohydraulic power steering, pressure control, closed-centre steering, Boost curve control, autonomous driving, hardware-...

show abstract

Development of a New Concept of Electrically Powered Hydraulic Steering

Cited by 12 publications

References 0 publications

Modeling, simulation, and experimental validation of electro-hydraulic power steering system in multi-axle vehicles

Modeling, simulation, and experimental validation of electro-hydraulic power steering system in multi-axle vehicles

Modeling, Simulation, and Experimental Investigation of an Electrohydraulic Closed-Center Power Steering System

On Electrohydraulic Pressure Control for Power Steering Applications : Active Steering for Road Vehicles

Contact Info

Product

Resources

About