The predictive functional control and the management of constraints in GUANAY II autonomous underwater vehicle actuators

Autonomous underwater vehicle control has been a topic of research in the last decades. The challenges addressed vary depending on each research group's interests. In this paper, we focus on the predictive functional control (PFC), which is a control strategy that is easy to understand, install, tune, and optimize. PFC is being developed and applied in industrial applications, such as distillation, reactors, and furnaces. This paper presents the rst application of the PFC in autonomous underwater vehicles, as well as the simulation results of PFC, fuzzy, and gain scheduling controllers. Through simulations and navigation tests at sea, which successfully validate the performance of PFC strategy in motion control of autonomous underwater vehicles, PFC performance is compared with other control techniques such as fuzzy and gain scheduling control. The experimental tests presented here offer effective results concerning control objectives in high and intermediate levels of control. In high-level point, stabilization and path following scenarios are proven. In the intermediate levels, the results show that position and speed behaviors are improved using the PFC controller, which offers the smoothest behavior. The simulation depicting predictive functional control was the most effective regarding constraints management and control rate change in the Guanay II underwater vehicle actuator. The industry has not embraced the development of control theories for industrial systems because of the high investment in experts required to implement each technique successfully. However, this paper on the functional predictive control strategy evidences its easy implementation in several applications, making it a viable option for the industry given the short time needed to learn, implement, and operate, decreasing impact on the business and increasing immediacy.Peer ReviewedPostprint (author's final draft

A survey on fractional order control techniques for unmanned aerial and ground vehicles

In recent years, numerous applications of science and engineering for modeling and control of unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) systems based on fractional calculus have been realized. The extra fractional order derivative terms allow to optimizing the performance of the systems. The review presented in this paper focuses on the control problems of the UAVs and UGVs that have been addressed by the fractional order techniques over the last decade

Multi-Objective Robust H-infinity Control of Spacecraft Rendezvous

Based on the relative motion dynamic model illustrated by C-W equations, the problem of robust Hinfin control for a class of spacecraft rendezvous systems is investigated, which contains parametric uncertainties, external disturbances and input constraints. An Hinfin state-feedback controller is designed via a Lyapunov approach, which guarantees the closed-loop system to meet the multi-objective design requirements. The existence conditions for admissible controllers are formulated in the form of linear matrix inequalities (LMIs), and the controller design is cast into a convex optimization problem subject to LMI constraints. An illustrative example is provided to show the effectiveness of the proposed control design method

Magnetic Microrobot Locomotion in Vascular System Using A Combination of Time Delay Control and Terminal Sliding Mode Approach

This thesis deals with designing a control law for trajectory tracking. The target is to move a microrobot in a blood vessel accurately. The microrobot is made of a ferromagnetic material and is propelled by a magnetic gradient coil. The controller combines time delay control (TDC) and terminal sliding mode (TSM) control. TDC allows deriving a control law without prior knowledge of the plant. As the system is a nonlinear function which also includes uncertainties and unexpected disturbance, TDC gives a benefit of less effort needed compared to model-based controller. Meanwhile, TSM term adds accuracy which it compensates TDC estimation error and also adds robustness against parameter variation and disturbance. In addition, anti-windup scheme acts as a support by eliminating the accumulated error due to integral term by TDC and TSM. So, the proposed controller can avoid actuator saturation problem caused by windup phenomenon. Simulations are conducted by copying a realistic situation. Accuracy and robustness evaluations are done in stages to see how each terms in a control law give an improvement and to see how an overall controller performs. ⓒ 2014 DGISTI. INTRODUCTION 1 -- 1.1. BACKGROUND 1 -- 1.2. RELATED RESEARCH 3 -- 1.3. OBJECTIVE 4 -- 1.4. SPECIFICATION 4 -- 1.5. SCOPE 5 -- 1.6. OVERVIEW 5 -- II. METHOD 6 -- 2.1. TIME DELAY CONTROL 6 -- 2.2. TERMINAL SLIDING MODE 9 -- 2.3. ANTI-WINDUP SCHEME 11 -- 2.4. PRACTICAL APPROACH 14 -- 2.4.1. FEEDBACK SIGNAL 14 -- 2.4.2. CONTROLLER GAIN SELECTION 15 -- 2.4.3. MEASUREMENT NOISE 16 -- 2.5. ADVANTAGES AND DRAWBACKS 16 -- III. RESULTS 17 -- 3.1. SIMULATION SETUP 17 -- 3.1.1. PLANT MODELING 18 -- 3.1.2. ACTUATOR AND POSITION SENSOR MODELING 20 -- 3.1.3. TRAJECTORY 21 -- 3.1.4. SIMULATION PARAMETER 21 -- 3.1.5. CONTROLLER TARGET 24 -- 3.2. ACCURACY AND ROBUSTNESS EVALUATION 24 -- 3.3. ANTI-WINDUP SCHEME EVALUATION 32 -- 3.4. SOLUTION FOR MEASUREMENT NOISE 35 -- 3.5. 2D SIMULATION 46 -- CONCLUSION AND FUTURE WORK 49 -- REFERENCES 50 -- 요 약 문(ABSTRACT IN KOREAN) 52이 논문은 경로 추적을 위한 컨트롤 법을 설계한 것이다. 목표는 혈관 내에서 정확하게 마이크로 로봇의 움직이는 것이다. 마이크로 로봇은 강자성체 물질로 만들어져 있고 자기장에 의해서 추진 된다. 컨트롤러는 시간지연제어기법(time delay control)과 terminal sliding 컨트롤을 함께 사용하였다. TDC는 플랜트에 대한 선행 지식 없이 적용할 수 있다. 시스템이 불확실함과 예상치 못한 외란을 포함하고 있는 비선형 일 때 TDC는 모델 기반의 컨트롤러에 비해 적은 노력이 드는 장정이 있다. 한편, TSM은 정확도를 더하여 TDC의 주정에러를 보상하고 또한 매개변수의 변화와 외란에 반한 견고함을 더한다. 게다가 안티 와인드 업은 TDC와 TSM의 적분 때문에 축적되는 에러를 제거하는 역할을 한다. 제안한 컨트롤러는 와인드업 현상에 의한 작동기의 포화현상을 피할 수 있다. 시뮬레이션은 실제 현상을 따라 시행되었다. 정확도와 견고함 평가는 전체적인 컨트롤러가 어떻게 수행하는가를 보는 것과 각각 컨트롤 방법이 주는 개선점을 보는 단계로 실시하였다. ⓒ 2014 DGISTMasterdCollectio

Determination of pilot and vehicle describing functions from the Gemini 10 mission

Three types of manual control maneuvers conducted during the Gemini-10 mission have been analyzed in order to measure and document the describing function of the pilot, the vehicle and the pilot-vehicle combination during an actual space mission. Measurements made from the data records of the reentry maneuver (a single axis control task) indicate that the pilot's control behavior changes during critical portions of the reentry. Measurements made of the deorbit maneuver and of a terminal phase initiation maneuver (three axis tasks) show that the pilot assigns priorities to the separate axes and controls them differently. His control technique is also influenced by the magnitude of the thrust disturbance present during the maneuvers. The results for all three types of maneuvers show that the pilot adapts to the nonlinear spacecraft control system in such a way that the combined pilot-vehicle dynamics take the form of the linear crossover model

Minimum Time Control of a Gantry Crane System with Rate Constraints

This paper focuses on the development of minimum time control profiles for point-to-point motion of a gantry crane system in the presence of uncertainties in modal parameters. Assuming that the velocity of the trolley of the crane can be commanded and is subject to limits, an optimal control problem is posed to determine the bang-off-bang control profile to transition the system from a point of rest to the terminal states with no residual vibrations. Both undamped and underdamped systems are considered and the variation of the structure of the optimal control profiles as a function of the final displacement is studied. As the magnitude of the rigid body displacement is increased, the collapse and birthing of switches in the optimal control profile are observed and explained. Robustness to uncertainties in modal parameters is accounted for by forcing the state sensitivities at the terminal time to zero. The observation that the time-optimal control profile merges with the robust time-optimal control is noted for specific terminal displacements and the migration of zeros of the time-delay filter parameterizing the optimal control profile are used to explain this counter intuitive result. A two degree of freedom gantry crane system is used to experimentally validate the observations of the numerical studies and the tradeoff of increase in maneuver time to the reduction of residual vibrations is experimentally illustrated