The rapid expansion of the semiconductor industry and the increasing demand for high speed, high precision positioning stages necessitate exceptionally precise active control of pneumatic vibration isolation tables. This study addresses these stringent requirements by employing a novel pneumatic valve to regulate airflow to the air springs of the vibration isolator. The novel valve incorporates an internal sensor for accurate poppet position monitoring which enables inner loop feedback (FB) control of the poppet position. This effectively compensates for airflow induced disturbances acting on the poppet. Consequently, rapid and precise air spring pressure regulation is achieved which results in accurate displacement control of the vibration isolator. The effectiveness of the proposed system is validated through experiments evaluating its ability to isolate vibration caused from a movable stage mounted on the isolator.

Train localization is a crucial technology in the railway industry, with increasing demand for cost-effective methods that eliminate reliance on ground-based equipment to reduce both costs and maintenance requirements. In this study, we propose a versatile train localization method applicable across diverse environments, including high-speed railways, conventional lines, urban settings, and rural areas. By integrating a high-speed, cost-effective one-dimensional LiDAR sensor with GNSS, MEMS IMU, and a Tachometer generator, the system can effectively recognize the surrounding environment and accurately determine the train's position. The proposed method ensures low-cost and high-accuracy train localization even in areas with dense surrounding structures or open-sky environments. Experimental results conducted on operational railway lines demonstrated a high success rate of 97 % in recognizing the surrounding environment and detecting train location using this approach. Moreover, the accuracy of train localization achieved through this method was found to be comparable to that of a loosely-coupled GNSS approach.

Semiconductor vertical furnaces are used in the semiconductor manufacturing process to perform deposition and oxidation on wafers. To increase the equipment throughput, a shorter process time is one of the criteria needed. To achieve this, this paper presents a control method consists of fast mode and tracking mode. The fast mode utilizes the maximum capacity of the actuators and is implemented as time-optimal control using binary search algorithm. The tracking mode is introduced to maintain constant temperature and deal with inaccuracies in the fast mode caused by plant unmodeled dynamics and time discretization. It is implemented as a two-degree-of-freedom control. Simulation results have shown that shorter rising time and settling time can be achieved by the fast mode and tracking mode respectively, resulting in the reduction of total process time.

In this paper the Indian Railway traction network is analyzed. Indian Railways gets its traction supply from the state-owned utility grid. With the shift in policy to manufacture only 3-φ locomotives in the future, there shall be enhanced feedback of regenerative braking energy (RBE) to the grid especially in the absence of another 3-φ locomotive to absorb this RBE. This can negatively impact the utility grid (due to the harmonics in RBE) and presently there is no provision to get remunerated for this reverse flow of energy. Thus, it is essential to efficiently utilize this RBE in the railway network itself. This can be achieved by adopting bilateral co-phase traction network configuration which can enhance the utilization of RBE. However, by making the traction supplies co-phase in adjacent traction substations there is a pronounced effect of circulating currents which can offset any advantage obtained due to RBE utilization. In this paper the feasibility of adopting bilateral co-phase traction network is examined by demonstrating the impact of difference of voltage magnitudes and phase angles on effective RBE utilization. The ideal range of these parameters for saving RBE is also demonstrated. A case study is done based on realistic data from Indian Railways.

In dynamic wireless power transfer, power fluctuation occurs due to coupling variation. This paper proposes a design method of compensation network to suppress the variation based on a geometrical interpretation of power transmission characteristics. This paper also shows the theoretical limitation of suppression of power fluctuation by designing compensation circuit. The proposed design is able to suppress the power fluctuation by more than 10 percent as compared to conventional methods. The simulation and experimental results show good agreement.

Wireless power transfer (WPT) for moving electric vehicles has been widely studied. LCC topology was proposed as a novel compensation circuit for dynamic WPT (DWPT) because inverter current is suppressed automatically according to the decrease in coupling coefficient. In addition, its characteristic enables a DWPT system to connect multiple transmitter coils to a single inverter. This paper proposed an optimal load condition under a multi-parallel operation considering waiting loss. Moreover, two types of LCC topologies are approximated into a Series-Series compensation topology, and the effective range of that approximation is derived. Calculation results revealed the effective range of the approximation. The proposed method improved transmission efficiency by up to 7% in the experiment.

This paper proposes a new approach for optimal allocation of wireless power transfer system (WPTSys) from a viewpoint of optimal control problem (OCP) for autonomous driving electric vehicles (EVs). These EVs are assumed to accurately follow a pre-determined speed profile. By transformation of the nonlinear optimization problem for optimal allocation of WPTSys to an OCP, well-known methods guaranteeing the global optimality of solution for the OCP are applied, such as Pontryagin's maximum principle or dynamic programming. Therefore, the global optimal solution of the allocation problem of WPTSys can be obtained. In addition, we consider a practical situation of EV operation from a probability point of view, where many EVs are operated with different initial battery state-of-charge.

In this paper, sensorless magnetic levitation for large air gap translational motion is investigated. Most of the research in this field has been for magnetic bearings whose system characteristics and control requirements are different from a translational moving vehicle. An obvious difference is the range of operational air gap. Furthermore, the quality of magnetic materials, in terms of laminations, saturation, etc. used is also different. Therefore, well developed sensorless methods for magnetic bearings cannot be directly applied to large air gap applications. Thus, a novel method is proposed for detecting air gap by injecting high frequency signal into the magnetic coil and measuring either rising or falling current-ripple slope (single slope detection) using high speed sampler. Resistance is simultaneously estimated as well. Finally, stable levitation using the detected air gap signal as control feedback is demonstrated experimentally.

Redundant systems are of interest in engineering because they bring additional capability for a task completion, allowing the system to perform sub-tasks or to improve performances. However, this also means that an extra degree of complexity is added to its resolution. For this purpose, proposed resolution schemes are classically based on the 2-norm minimization, also called pseudo-inverse, whose popularity stems from its easy analytical resolution, but suffers from not considering physical constraints, like input bounds. To tackle this issue, the infinity-norm resolution has been proposed, which determines a minimum-effort solution, taking into consideration individual magnitudes and offering the full physically realisable outputs space. Despite its guaranteed merits, it has only been considered for a few, low-order system because of its lack of analytical resolution. This paper proposes a novel approach on the minimum infinity-norm resolution for single-degree systems, which represent a large part of the most popular redundant configurations. This approach offers a closed-form solution, thus giving an analytical resolution allowing convenient computation and a description of the solution based on parameters of the system. Implementation of this new method is simulated on single-degree kinematically redundant systems to show the superiority of infinity-norm resolution over 2-norm resolution.

Redundancy in systems is valued for its ability to add additional dexterity in task completion, but its utilization implies an added degree of complexity which must be resolved at runtime. The majority of resolution methods have focused on resolution using some variant of the 2-norm optimizing pseudo-inverse. While tractable, the pseudo-inverse fails to consider input bounds and often resolves systems with input values unrealizable given physical parameters. The Cascaded Generalized Inverse (CGI) was introduced to incorporate maximum input bounds and extend the output space of the pseudo-inverse by iteratively reallocating joint contributions to underutilized inputs. This paper discusses the discontinuities which arise in resolution of systems utilizing CGI, and proposes a constrained CGI, which overcomes this discontinuity. Proof of continuity is provided, and the constrained and unconstrained CGI systems are simulated and compared with application to kinematically-redundant robotic manipulators.

In Linear Induction Motor for rail-guided transportation, to meet the demand for reducing transverse edge-effect and correspond to the end ring of rotary induction motor, various types of the construction of secondary reaction plate have been considered. In order to demonstrate the characteristics of each model, this paper describes the fundamental mathematical formulation of the simplified field calculation as well as the simulation results through 3-dimensional numerical analysis.

There is a rising interest in bi-articular actuation for solving the known limitations of conventional robot arms. Actuator redundancy resulting from bi-articular actuation bring advantages such as increasing movement stability and efficiency in end effector force production. Actuator redundancy resolution is the first step in the control design for these robots, representing a key aspect for their performances. The Phase Different Control (PDC) resolves actuator redundancy on the basis of a linearized model derived from measured human muscle activity. Such linear model produces a non zero error in calculation between a desired output force and necessary inputs. In our previous work, the Non-Linear Phase Different Control (NLPDC) has been proposed to resolve actuator redundancy with no error under static conditions. In this work, NLPDC is implemented under dynamic conditions, and compared with PDC by simulating the dynamics a two-link planar arm. Performances such ad settling time and position error are highly improved when using NLPDC.