Abstract: We present a robot system for in-pipe inspection of underground urban gas pipelines. The robot is configured as an articulated structure like a snake with a tether cable. Two active driving vehicles are located in front and rear of the system, and passive modules such as a control module are chained between the active vehicles. The proposed robot has outstanding mobility offered by a new steering mechanism, called double active universal joint, which makes it possible to cope with complicated configurations of underground pipelines. Characteristic features of the system are described and the construction of the system is briefly outlined.

Abstract: In this report, the authors examine the applicability of haptic displays for rear-end collision avoidance warnings. Concepts and published research studies are reviewed in the report. This is followed by three small-scale studies of mono-pulse braking and active steering displays. Two parameter setting studies are first discussed. The first examined the display parameter settings of a mono-pulse braking display, while the second examined the effects of active steering vibration amplitude frequency, and duration on display detectability and appropriateness ratings. Based on the results obtained, the authors suggest that active steering displays be reserved for future collision avoidance system integration. In the third study, the authors examined the response of drivers in a car following situation to a mono-pulse braking display under two different simulated rear-end collision avoidance warning scenarios. Results suggest that mono-pulse braking displays might be of use in rear-end collision avoidance applications.

Abstract: The paper presents control strategies for the active steering of solid axle railway vehicles using the linear quadratic Gaussian (LQG) method. The paper investigates the benefits of actively controlling and steering the wheelsets of a railway vehicle and studies what could be achieved when modern control techniques are used on the vehicles via mechatronic components. An optimal H/sub 2/ controller is developed for the active steering and is fine-tuned using genetic algorithms. A Kalman filter is developed to provide the full state feedback required by the optimal control. The Kalman filter is formulated in such a way that it not only estimates all the vehicle states, but also calculates parameters such as curve radius and cant of the railway track on which the vehicle is travelling. Computer simulations are used in the study to assess the system performance with the control scheme proposed.

Abstract: Presents coprime factors based two-degree-of freedom H/sub /spl infin// control for vehicle handling improvement. Control synthesis uses a linear vehicle model which includes the yaw motion and disturbance input. The synthesis procedure allows the separate processing of the robust stabilization problem and reference signal or disturbance rejection. The control action is applied as an additional steering angle, by combination of the driver input and feedback of the yaw rate. The synthesized controller is tested in both disturbance rejection and driver imposed yaw reference tracking maneuvers. The maneuvers are completed at different speeds and road conditions.

Abstract: This paper describes an original active steering device for endoscopes and boroscopes. Its mechanical structure is based on a tubular hyper-redundant mechanism. Distributed SMA actuators with their own local controller are integrated in this structure for producing bending forces in reaction to the interaction detected between the instrument and its environment.

Abstract: Steering of the vehicles on a slippery highway is a difficult task for most passenger car drivers. The steering vehicles on slippery roads tend to slide outward with less lateral forces than on nor mal roads. When the drivers notice that their vehicles on a slippery highway start to depart from the cornering lane, most of them make a sudden steering and/or braking, which in turn may induce spin-out and instability on their vehicles. In this paper, an active steering control method is proposed such that the vehicles in slippery roads are steered as if they are driven on the normal roads. In the proposed method, the estimated lateral forces acting on the steering tires are compared with the reference values and the difference is compensated by the active steering method. A fuzzy logic controller is designed for this purpose and evaluated on a steering Hardware-In-the-Loop Simulation (HILS) system. Steering performance results on the slippery curved and sinus roads demonstrate the effectiveness of the proposed controller. This method can be realized with the steer-by-wire concept and is promising as an active safety technology.

Abstract: With the aim of improving vehicle stability through the introduction of active steering control, the authors undertook the development of a steer-by-wire system which is more effective than the direct yaw-moment control (DYC) while avoiding interference with driver steering. The vehicle stability control begins only after a change in vehicle behavior has been detected, and therefore in the case of full braking test on a /spl mu/-split road and in other situations requiring high responsiveness, the vehicle stabilizing effect is lowered due to time lag until the control starts, and a residual yaw angle is created after the stopping of the vehicle. In order to resolve these problems, a new type of control was developed whereby the driver's steering intent is detected based on the DYC behavior and front-wheel angle deviation between front-wheel rotational speeds. It was verified by on-vehicle testing that the addition control resulted in greater vehicle stability.

Abstract: It is a universal trend that automotive engineers tend to use fast digital computers to develop advanced vehicle systems. They can design, analyze, and test their systems using computer simulation before physically manufacturing them. It is still questionable how these advanced systems would react with the human driver. One way to deal with this problem is to develop a computer model that is capable of controlling the vehicle in a way similar to human driver behavior. Fuzzy logic inference systems are known of their great ability to simulate human reasoning process as well as the possibility of being further trained to mimic specific human control process. This paper presents a new driver model using fuzzy logic controls. The model is designed to control the longitudinal as well as the lateral motions of the vehicle by performing simultaneous steering and braking commands. The model is tested on a vehicle model having an integrated active steering and direct yaw control strategy as developed by this paper's authors in [1]. The results show success of this fuzzy model in simulating driver control actions in curve following and collision avoidance maneuvers.

Abstract: In order to reduce the lateral force between wheel and rail during curve negotiation, the possibility of railway trucks with actively steered wheelset has been investigated. This paper deals with a basic study about the active steering trucks, which employs force control that is proportional to bogie angle. Three different types of steering control are compared under the condition of expected operation speeds of +45km/h over the regulation, and the control type that steers only leading axles in each truck is recognized to be appropriate. Here, tilting trains with the tilt angle of 7 degrees are premised. The wheel lateral forces are compared with those of usual tilting trains without steering mechanism running at speed of +25km/h. Simulation results show that the wheel lateral force of the leading axle in the active steering truck is smaller than that of other trucks. The active steering truck shows also its superiority over the conventional trucks on the axle lateral force under the practical curving condition with truck irregularities.

Abstract: The rotational unit(3) of the suspension is constructed as an active steering unit with at least one oscillating motor with at least one pressure chamber. By means of the motor the rotational unit and lift unit(4) are simultaneously rotatable to produce a steering moment in relation to the outer housing(2) attached to the frame of the vehicle. The rotational unit and lift unit are located one inside the other and locked against twisting in relation to each other for the simultaneous transmission of steering moment. An Independent claim is included for a vehicle, especially a land or forestry vehicle, equipped with the proposed suspension.

Abstract: This paper describes an original active steering device for endoscopes and boroscopes. Its mechanical structure is based on a tubular hyper-redundant mechanism. Distributed SMA actuators with their own local controller are integrated in this structure for producing bending forces in reaction to the interaction detected between the instrument and its environment. The SMA actuators are two thin NiTi springs in an antagonist configuration. Joint actuation relies on martensite/austenite phase transformation in NiTi alloys. The global behavior of the endoscope is controlled through a multi-agent approach.

Abstract: The authors have developed a Steer by Wire (SBW) system that has no mechanical linkage between a steering wheel and steering gear. SBW is suitable for active steering control because its steering actuator and reactive actuator providing reactive force to the steering wheel are electrically and independently controlled. A previously proposed type of control for vehicle stability with SBW active steering control not only stabilized vehicle dynamics against external disturbance but also possessed the significant advantage of reducing braking distance during sudden braking on mu-split roads. However, the active steering control of this system delayed and yaw angle of the vehicle remained after the vehicle had stopped because the control started working only after a change in vehicle behavior had been detected. In this paper, a new control method that reduces the above delay is proposed, its effectiveness confirmed, and the results of on-vehicle testing presented. For the covering abstract see ITRD E114174.

Abstract: The method involves detecting whether a situation exist whereby a demand value step of an additional steering angle (deltaM) can occur or not; detecting whether a sudden demand value change for the additional steering angle has actually occurred or not; and performing a smooth change from the old demand value to the new demand value according to a defined smoothing function. An Independent claim is also included for an active steering system for implementing the method.

Abstract: PROBLEM TO BE SOLVED: To properly restrain a steering reaction force so as to improve a steering feeling in an active steering system with a superposition transmission by increasingly or decreasingly controlling an operation torque strength according to a jumped up value of an additional steering angle by an electric servo motor when it occurs SOLUTION: A steering wheel angle δL of a steering mechanism steered by a steering wheel 31 of a vehicle 35 is detected by a steering wheel angle sensor 38, and the detection value is inputted to an open-close loop control unit 37 An additional steering angle δM by an electric servo motor 33 is superposed on the angle δL at a transmission 32, and the superposed angle δL' is fed to a steering gear box 34 At this time, when a jump occurs in a target value of the angle δM, such control is made that the steering torque strength is reduced if there is no dangerous condition in the running dynamic aspect, while it is increased if there is a dangerous condition

Abstract: Very short headway train operation is required for realizing better urban transport services in recent years. The very short train operation at a turnout enables various novel methods of train operation, such as nonstop operation of certain coaches while the rest part of the train stops after decoupling in its approach to a station, and more efficient usage of coaches by frequent coupling/decoupling vehicles at many junctions. This type of operation has been restricted by uncertainty of existing wayside turnout devices. The paper briefly explains the advantage of the on-board switching from the system's point of view. Steering through a control of independently motored wheels is one of the most feasible technical alternatives for realizing the function of the on-board turnout. The study analyzed dynamics of a single axis boggie with independently motored wheels and examined the active steering control through simulations. The controller was designed based on Kessler's canonical form. One can estimate these variables by measuring the lateral displacement and applying a Luenberger state observer to the control system. The extended observer can be used also to estimate the lateral force.

Abstract: This paper presents the development of a modal control strategy for the active steering of solid axle railway vehicles and reveals benefits of actively stabilising the wheelsets of a railway vehicle. A modal decomposition is applied to a 2-axle railway vehicle to de-couple its body lateral and yaw motions and hence to allow more detailed analysis of the vehicle behaviour and more robust design of active controllers. Independent controllers for the two motions are developed based on the two de-coupled modes. Parameter variations such as creep coefficients and wheelset conicity are taken into account in the design process to guarantee a robust design. The study shows that, compared to a passive vehicle, the vehicles with actively steered wheelsets not only perform much better on a curved track, but also improve the ride quality on straight track. Computer simulations are used in the study to verify the development of the controllers and assess the system performance with the control scheme proposed.