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Discusses the vibration suppression control of a piezoelectric actuated suspension dual-servo system. Modeling of the sensor and the actuator; Frequency response of the sensor and the actuator; Vibration suppression controller design.

A control scheme for emergency braking of vehicles is designed. The tire/road friction is described by a LuGre dynamic friction model. The control system output is the pressure in the master cylinder of the brake system. The controller utilizes estimated states for a feedback control law that achieves a near maximum deceleration. The state observer is designed using linear matrix inequality (LMI) techniques. The analysis shows that using the wheel angular speed information exclusively is not sufficient to rapidly estimate the velocity and relatively velocity, due to the fact that dynamic system is almost unobservable with this measurement as output. Findings are confirmed by stimulation results that show that the estimated vehicle velocity and relative velocity converge slowly to their true values, even though the internal friction state and friction parameter converge quickly. The proposed control system has two main advantages when compared with an antilock braking system (ABS); (1) it produces a source of a priori information regarding safe spacing between vehicles that can be used to increase safety levels in the highway; and (2) it achieves a near optimal braking strategy with less chattering. [ABSTRACT FROM AUTHOR]

Describes a control scheme for emergency braking maneuvers in automated highway systems and an online identification scheme to determine the tire-road friction characteristics of the vehicle. Required pressure in the master cylinder of the braking system to achieve maximum deceleration during braking; Maximum coefficient of friction.

Presents the design, fabrication and performance of an uncooled micro-optomechanical infrared imaging system. Measures the deflections of the cantilever beams in the focal-plane array; Theoretical noise-equivalent temperature difference of the system; Detection of resolution of the design.

This paper presents the design of a velocity tracking controller for safe vehicle maneuvering in Automated Highway Systems (AHS) in which traffic is organized into platoons of closely spaced vehicles. The notion of safety is related to the absence of collisions that exceed a given relative velocity threshold. In a companion paper, state dependent safety regions for the platoons are designed in such a way that, whenever the state of a platoon is inside these safety regions, it is guaranteed that platoon maneuvering will be safe and follow the behavior prescribed by the finite state machines that control vehicles maneuvers. Velocity profiles inside these safety regions are derived for all the single lane maneuvers anda nonlinear velocity tracking controller is designed to track these profiles. This controller attempts to complete the maneuvers with comfort in minimum time, whenever safety is not compromised. The control schemes presented in this paper were implemented and tested using AHS simulation software. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of designing safe controllers for vehicle manuevering in Automated Highway Systems (AHS) in which traffic is organized into platoons of closely spaced vehicles. Conditions to achieve safe platooning under normal modes of operation are investigated. The notion of safety is related with the absence of collisions that exceed a given relative velocity threshold. State dependent safety regions for the platoons are designed in such a way that, whenever the state of a platoon is inside these safety regions, it is guaranteed that platoon maneuvering will be safe and follow the behavior prescribed by the finite state machines that control vehicles manuevers. It is shown that it is possible to design control laws that keep the state of the platoons inside these safety regions. The results obtained allow one to decouple the controllers for the regulation of the manuevers and the finite state machines that determine their proper sequence in AHS architectures. The overall complexity of the design and verification of the AHS as an hybrid system is therefore greatly reduced. [ABSTRACT FROM AUTHOR]

Presents information pertaining to the microelectromechanical factors associated with the angular electrostatic microactuators for use in magnetic disk drives. Information on the attachment of the electromagnetic voice-coil motor (VCM); Description of the actuators; Reference to a simplified fabrication process flow.

• We have modified the introduction and rewritten parts of it to highlight the importance of our work and discuss how it is different from the previous work. • We have included a detailed description of our simulation study so that the reader can go over the setting of the simulation. • We have changed some of the plots of the mixed-autonomy section as there was a mistake in our previous results. • We have also changed the notation. Vehicle bypassing is known to increase delays at traffic diverges. However, due to the complexities of this phenomenon, accurate and yet simple models of such lane change maneuvers are hard to develop. In this work, we present a macroscopic model for predicting the number of vehicles that perform a bypass at a traffic diverge when taking an exit link. We interpret the bypassing maneuver of vehicles at a traffic diverge as drivers acting selfishly; every vehicle selects lanes such that its own cost of travel is minimized. We discuss how we model the costs that are incurred by the vehicles. Then, taking into account the selfish behavior of vehicles, we model the lane choice of vehicles at a traffic diverge as a Wardrop equilibrium. We state and prove the properties of the equilibrium in our model. We show that there always exists an equilibrium for our model. Moreover, although our model is an instance of nonlinear asymmetrical routing games which in general have multiple equilibria, we prove that the equilibrium of our model is unique under certain assumptions that we observed to hold in all our case studies. We discuss how our model can be calibrated by running a simple optimization problem. Then, using our calibrated model, we validate it through simulation studies and demonstrate that our model successfully predicts the aggregate lane change maneuvers that are performed by vehicles at a traffic diverge. Having shown the predictive power of our model, we discuss how our model can be employed to obtain the optimal lane choice behavior of vehicles, where the social or the overall cost of all vehicles is minimized. Finally, we demonstrate how our model can be utilized in scenarios where a central authority can dictate the lane choice and trajectory of certain vehicles, for example autonomous vehicles directed by a central authority, so as to increase the overall vehicle mobility at a traffic diverge. Examples of such scenarios include the case when both human driven and autonomous vehicles coexist in the network. [ABSTRACT FROM AUTHOR]

Macroscopic traffic models are necessary for simulation and study of traffic’s complex macro-scale dynamics, and are often used by practitioners for road network planning, integrated corridor management, and other applications. These models have two parts: a link model, which describes traffic flow behavior on individual roads, and a node model, which describes behavior at road junctions. As the road networks under study become larger and more complex — nowadays often including arterial networks — the node model becomes more important. Despite their great importance to macroscopic models, however, only recently have node models had similar levels of attention as link models in the literature. This paper focuses on the first order node model and has two main contributions. First, we formalize the multi-commodity flow distribution at a junction as an optimization problem with all the necessary constraints. Most interesting here is the formalization of input flow priorities. Then, we discuss a very common “conservation of turning fractions” or “first-in-first-out” (FIFO) constraint, and how it often produces unrealistic spillback. This spillback occurs when, at a diverge, a queue develops for a movement that only a few lanes service, but FIFO requires that all lanes experience spillback from this queue. As we show, avoiding this unrealistic spillback while retaining FIFO in the node model requires complicated network topologies. Our second contribution is a “partial FIFO” mechanism that avoids this unrealistic spillback, and a (first-order) node model and solution algorithm that incorporates this mechanism. The partial FIFO mechanism is parameterized through intervals that describe how individual movements influence each other, can be intuitively described from physical lane geometry and turning movement rules, and allows tuning to describe a link as having anything between full FIFO and no FIFO. Excepting the FIFO constraint, the present node model also fits within the well-established “general class of first-order node models” for multi-commodity flows. Several illustrative examples are presented. [ABSTRACT FROM AUTHOR]