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This paper explores the potential of the Series Active Variable Geometry Suspension (SAVGS) for comfort and road holding enhancement. The SAVGS concept introduces significant nonlinearities associated with the rotation of the mechanical link that connects the chassis to the spring-damper unit. Although conventional linearization procedures implemented in multi-body software packages can deal with this configuration, they produce linear models of reduced applicability. To overcome this limitation, an alternative linearization approach based on energy conservation principles is proposed and successfully applied to one corner of the car, thus enabling the use of linear robust control techniques. An H ∞ controller is synthesized for this simplified quarter-car linear model and tuned based on the singular value decomposition of the system's transfer matrix. The proposed control is thoroughly tested with one-corner and full-vehicle nonlinear multi-body models. In the SAVGS setup, the actuator appears in series with the passive spring-damper and therefore it would typically be categorized as a low bandwidth or slow active suspension. However, results presented in this paper for an SAVGS-retrofitted Grand Tourer show that this technology has the potential to also improve the high frequency suspension functions such as comfort and road holding. [ABSTRACT FROM AUTHOR]

With the demand for energy efficiency in electro-hydraulic servo system (EHSS) increasing, the separate meter in and separate meter out (SMISMO) control system draws massive attention. In this paper, the SMISMO control system was decoupled completely into two subsystems by the proposed indirect adaptive robust dynamic surface control (IARDSC) method. Besides, a fast parameter estimation scheme was proposed to adapt to the parameter change for a better estimation performance. Also, a supply pressure controller with a disturbance observer and a supply flow rate controller with a grey model predictor were investigated and employed to save the power consumption. Finally, experimental results showed that the proposed IARDSC could achieve a good trajectory tracking performance with the fast parameter estimation. Meanwhile, the two energy saving techniques were validated. [ABSTRACT FROM AUTHOR]

Off-highway vehicles have not received the same level of scrutiny that their on-highway counterparts did relative to safety, comfort, fuel economy, and automation. Over the past few decades, various active chassis safety control systems, architectures, and schemes have been researched and developed to improve the stability and handling of on-highway vehicles, including articulated vehicles such as tractor–trailer applications. In this paper, the authors investigate a yaw stability control system for articulated frame steering off-highway vehicles via novel steer-by-wire technology that they have recently developed. A high-fidelity vehicle dynamics model is derived while keeping the yaw rate decoupled from the lateral acceleration, in order to separate the primary path-following task (driver) from the secondary disturbance–attenuation task (controller). The control algorithm is then designed such that the two tasks do not hamper one another, and that the automatic controller is quickly activated for a short period of time to counteract instabilities, and then smoothly relinquishes control back to the human operator. Simulation and experimental testing results are obtained to validate the vehicle dynamics model, the control algorithm design, and the new system's efficacy in counteracting yaw instabilities on low-friction surfaces using standard vehicle dynamic maneuvers. [ABSTRACT FROM AUTHOR]

In the presence of stiction, the control valves may present an oscillatory behaviour that affects the regulatory control performance, thereby causing a loss of product quality and increasing energy consumption. Detection of stiction in the early phase is a crucial key for process control to avoid major disruptions to the plant operations. In this paper, a novel technique based on a well-developed fuzzy clustering approach is proposed. Based on a dramatic change of the slope of the lines obtained from successive cluster centres in the presence of stiction, a new performance index to distinguish the cause of oscillation is proposed. The simulation, experimental and industrial results are provided. [ABSTRACT FROM AUTHOR]

Abstract: This paper shows the similarity between transportation networks and thermodynamic systems. In particular, by regarding the vehicles as the energy stored in the system, it is demonstrated that transportation systems can have a similar notion of entropy. This transportation entropy is the measure of disorder and it is not only a suitable notion for evaluating the system performances, but also very useful for the control issue. With this in mind, by using dissipativity approach and choosing the entropy as storage function, a traffic signal control strategy is presented by means of Linear Matrix Inequality (LMI). This generation of dissipativity decreases the disorder and consequently renders the system better organized. Finally, a four-intersection system is studied in order to illustrate the performance of the results. [Copyright &y& Elsevier]

Abstract: In this paper, the performance potential of a new hardware combination for active suspension systems is presented. It consists of a low bandwidth actuator and a continuously variable damper, a setup that is shown to be competitive to high bandwidth active suspension systems especially if energy, cost and implementability aspects are taken into account. This is achieved by an iterative optimization procedure for the damping ratio and the weights of time-invariant LQR controllers for active quarter-car models. The results of the procedure are obtained by simulations employing a road disturbance model that is validated using measurements of a real highway profile. The achievable performance of the new hardware combination is compared to passive and high bandwidth active suspension systems by means of carpet plots. Based on the comparison results, it is shown that ride comfort can be significantly increased while satisfying given constraints for ride safety (maximum tire deflections) and suspension travel. [Copyright &y& Elsevier]

Abstract: The paper focuses on investigating thermal-transients effects, associated to intermittent use of internal combustion engine (ICE), on fuel economy and hydrocarbon (HC) emissions of series hybrid solar vehicles (HSVs). An offline, non-linear constrained optimization is set-up to individuate the ICE power trajectory that simultaneously minimizes fuel consumption, suitably operates the battery and fully exploits daily solar contribution. The results highlight the importance of including thermal transients in HSV energy management. The combined effects of engine, generator and battery losses, along with cranking energy and thermal transients, produce non-trivial solutions for the engine/generator group, which should not necessarily operate at its maximum efficiency. [Copyright &y& Elsevier]