Advanced Robust Control Design For High Speed Tilting Trains

Tilting is a worldwide accepted technology concept in railway transportation. The particular benefit from tilting trains use is reduction in journey times due to speed increase on track corners (while maintaining acceptable passenger comfort), a point that facilitates improved customer service. An additional benefit is cost effectiveness due to the train running on existing rail tracks. Many countries opted to using tilting trains as means of fast public transportation (UK, USA, Canada, Sweden, Norway, Switzerland, Germany, Japan). The industrial norm of tilting high speed trains is that of precedence tilt whereby preview tilt enabling signals are used to provide the required information to the vehicles (it can also use a combination of track database information or GPS but the concept is the same). Precedence tilt tends to be complex (mainly due to the signal interconnections between vehicles and the advanced signal processing required for monitoring). Research studies of earlier than precedence schemes,i.e. the so-called nulling-type schemes whereby local-per-vehicle signals are used to provide tilt (a disturbance rejection-scheme although tends to suffer from inherent delays in the control feedback), are still an important research aim due to the simple nature and most importantly due to the more straightforward fault detection compared to precedence. Use of nulling-type tilt has been supported by recent studies in this context. The research presented in this thesis highly contributes to simplified single-inputsingle-output robust tilt control using the simplest rail vehicle tilt structure, i.e. an Active Anti-Roll Bar. Proposed are both robust conventional (integer-type) control approaches and non-conventional (non-integer) schemes with a rigorous investigation of the difficult to achieve deterministic/stochastic tilt trade-off. Optimization has been used extensively for the designs. A by-product of the work is the insight provided into the relevant tilting train model Non Minimum Phase characteristics and its link to uncertainty for control design. Work has been undertaken using Matlab, including proper assessment of tilt ride quality considerations

Core power control analysis and design for triga nuclear reactor

An efficient nuclear core power control is essential in providing a safe and reliable nuclear power generation system. It is technically challenging to ensure that the core power output is always stable and operating within acceptable error bands. The core power control in TRIGA PUSPATI Reactor (RTP) Malaysia is designed based on the Feedback Control Algorithm (FCA), which includes the Proportional- Integral controller, Control Rod Selection Algorithm (CRSA), Control Rod Velocity Design (CRVD), and Power Change Rate Constraint (PCRC). However, the current setting generally produces an unsmooth transient response and a long settling time. The conventional CRSA suffers during transient and fine-tuning conditions due to the rod selection process only considers the rod position and ignores the rod worth value. The conventional PCRC has a constant gain, incapable of providing a sufficient amount of penalty and sensitivity effects on control rod velocity under all operating conditions. Thus, a new strategy for each component in the FCA is investigated to further improve overall core power tracking performance. To address the current CRSA problems, a novel CRSA called Single Control Absorbing Rod (SCAR) is designed based on the rod worth value and operational condition-based activation. The SCAR is not only reducing the complexity of the CRSA process but also reduces the time required for rod selection. In addition, a new saturation model and velocity value are studied for CRVD. On top of that, a fuzzy-based PCRC is proposed to produce a fast-tracking power response. Finally, a hybrid controller based on the integration of Model Predictive Control and Proportional controller is developed to exploit the benefits of both controllers via a switching control mechanism. In the present study, the RTP model is derived based on equations of neutronic, thermal-hydraulic, reactivity, and dynamic rod position. Both analytical and system identification models are considered. In the proposed design strategy, all of the safety design requirements based on the Final Safety Analysis Report are taken into account, ensuring that the outcome of the study is practical and reliable. The proposed strategy is designed via simulation with MATLAB Simulink and experimentation with actual hardware at the RTP. A stability analysis based on Lyapunov is derived to numerically guarantee the stability of the new power controller. An extensive comparison to the existing FCA is presented to demonstrate the compatibility and effectiveness of the proposed strategies in nuclear reactor environments. Overall, the results show that the response from hybrid Model Predictive Control-Proportional (MPC-P) offers better results than the FCA, in which reduces the rise time by up to 73 %, the settling time by up to 70 %, and the workload by up to 42 %. The hybrid MPC-P with multiple-component constraints is able to solve the unsmooth transient response and a long settling time tracking performance at the RTP and offers improvements in terms of fuel economic aspect in the long run and extending the lifetime of the plant operation

Implementation of Automatic DC Motor Braking PID Control System on (Disc Brakes)

The vital role of an automated braking system in ensuring the safety of motorized vehicles and their passengers cannot be overstated. It simplifies the braking process during driving, enhancing control and reducing the chances of accidents. This study is centered on the design of an automatic braking device for DC motors utilizing disc brakes. The instrument employed in this study was designed to accelerate the vehicle in two primary scenarios - before the collision with an obstacle and upon crossing the safety threshold. It achieves this by implementing the Proportional Integral Derivative (PID) control method. A significant part of this system comprises ultrasonic sensors, used for detecting the distance to obstructions, and rotary encoder sensors, which are utilized to measure the motor's rotational speed. These distance and speed readings serve as essential reference points for the braking process. The system is engineered to initiate braking when the distance value equals or falls below 60cm or when the speed surpasses 8000rpm. During such events, the disc brake is activated to reduce the motor's rotary motion. The suppression of the disc brake lever is executed pneumatically, informed by the sensor readings. Applying the PID method to the automatic braking system improved braking outcomes compared to a system without the PID method. This was proven by more effective braking results when the sensors detected specific distance and speed values. Numerous PID tuning tests achieved optimal results with K_p = 5, K_i = 1, and K_d = 3. These values can be integrated into automatic braking systems for improved performance. The PID method yielded more responsive braking outcomes when applied in distance testing. On the contrary, the braking results were largely unchanged in the absence of PID. Regarding speed testing, the PID method significantly improved the slowing down of the motor speed when it exceeded the maximum speed limit of 8000 rpm. This eliminates the possibility of sudden braking, thus maintaining the system within a safe threshold. The average time taken by the system to apply braking was 01.09 seconds, an indication of its quick responsiveness. This research is a valuable addition to control science, applying the PID control method to automatic DC motor braking. It provides valuable insights and concrete applications of PID control to complex mechatronic systems. It is also noteworthy for its development and optimization of suitable PID parameters to achieve responsive and stable braking. The study, therefore, offers a profound understanding of how PID control can be employed to manage braking systems on automatic DC motors, thereby advancing knowledge and application of control in control science and mechatronics

Optimised configuration of sensing elements for control and fault tolerance applied to an electro-magnetic suspension system

New technological advances and the requirements to increasingly abide by new safety laws in engineering design projects highly affects industrial products in areas such as automotive, aerospace and railway industries. The necessity arises to design reduced-cost hi-tech products with minimal complexity, optimal performance, effective parameter robustness properties, and high reliability with fault tolerance. In this context the control system design plays an important role and the impact is crucial relative to the level of cost efficiency of a product. Measurement of required information for the operation of the design control system in any product is a vital issue, and in such cases a number of sensors can be available to select from in order to achieve the desired system properties. However, for a complex engineering system a manual procedure to select the best sensor set subject to the desired system properties can be very complicated, time consuming or even impossible to achieve. This is more evident in the case of large number of sensors and the requirement to comply with optimum performance. The thesis describes a comprehensive study of sensor selection for control and fault tolerance with the particular application of an ElectroMagnetic Levitation system (being an unstable, nonlinear, safety-critical system with non-trivial control performance requirements). The particular aim of the presented work is to identify effective sensor selection frameworks subject to given system properties for controlling (with a level of fault tolerance) the MagLev suspension system. A particular objective of the work is to identify the minimum possible sensors that can be used to cover multiple sensor faults, while maintaining optimum performance with the remaining sensors. The tools employed combine modern control strategies and multiobjective constraint optimisation (for tuning purposes) methods. An important part of the work is the design and construction of a 25kg MagLev suspension to be used for experimental verification of the proposed sensor selection frameworks

Diseño de una estrategia de reducción de variabilidad en procesos con controladores tipo PID frente a perturbaciones oscilatorias

La calidad y el costo de los productos de las plantas industriales se ven afectados por la variabilidad inevitable en los procesos, sumado a las distintas perturbaciones que se presenten en el proceso. Desde la perspectiva del control automático de procesos, las perturbaciones oscilatorias son perjudiciales tanto porque afecta componentes mecánicos del proceso como porque su propagación conlleva a un aumento en la varianza del proceso. De igual forma, el rendimiento financiero de un proceso industrial se ve influenciado de manera negativa por lazos de control con controladores pobremente sintonizados, y que no fueron concebidos para actuar de manera óptima ante las perturbaciones mencionadas. Usualmente los controladores se han sintonizado para que la variable controlada alcance un valor fijo deseado ante un cambio abrupto en el sistema. Por todo lo anterior, en el marco de esta investigación se desarrolló una técnica de reducción de variabilidad en lazos de control en procesos con controladores tipo PID frente a perturbaciones oscilatorias mediante la re-sintonización del controlador. La metodología contemplada abarcó dos rutas, primero se realizó un desarrollo analítico y posteriormente uno experimental desde un punto de vista computacional, en donde se utilizó la función de transferencia del controlador como mecanismo para predefinir el comportamiento de la función de transferencia en lazo cerrado. A partir de estos desarrollos se obtuvo mejores resultados que al utilizar sintonías tradicionalmente implementadas