Paolo Mercorelli

Bio: Paolo Mercorelli is an academic researcher from Lüneburg University. The author has contributed to research in topics: Actuator & Control theory. The author has an hindex of 23, co-authored 304 publications receiving 2063 citations. Previous affiliations of Paolo Mercorelli include ABB Ltd & Autonomous University of Baja California.

A Two-Stage Augmented Extended Kalman Filter as an Observer for Sensorless Valve Control in Camless Internal Combustion Engines

Abstract: Camless internal combustion engines offer improvements over traditional engines in terms of improved torque performance and fuel economy, lower emissions, and pumping losses. Theoretically, their control flexibility provides electromagnetic valve actuators with the highest potential for improving efficiency. Sensorless control is one of the most important issues when implementing this new technology. The main contribution of this paper is a proposed observer comprising an augmented extended Kalman filter (EKF) and another EKF, which results in a sensorless control. The observer estimates the inductance of the actuator, which may vary. The proposed combination achieves a numerically efficient estimation. The proposed state observation structure avoids bulky and complicated measurement systems, which is an important advancement for real world applications. The introduced method is general and can be applied to problems in which it is not feasible or affordable to obtain position and velocity measurements. The current is measured, the position and the velocity of the electromagnetic valve are estimated with a robust method. The effectiveness of the proposed method is demonstrated using measured data acquired from an experimental setup based on an innovative electromagnetic valve actuator. A detailed comparative analysis of the arithmetic operations of the algorithm is also reported.

A Two-Stage Sliding-Mode High-Gain Observer to Reduce Uncertainties and Disturbances Effects for Sensorless Control in Automotive Applications

Abstract: In this paper, a sensorless control of an electromagnetic valve actuator for automotive applications is presented. Based on a nonlinear model, a switching esti mator combined with a two-stage observer structure is proposed. The presented structure is basically a high-gain observer (HGO) to reduce the effects of the uncertainties on the electromagnetic valve actuator model and unmeasurable external disturbances coming from the burning phase of the engine and acting against the actuator movement. The proposed sliding-mode observer has the capability of guaranteeing zero average estimation error in finite time, even in the presence of model uncertainties and bounded disturbances. Considerations on constructive aspects concerning observability are made. Two constructive propositions are proven in this paper to realize the observer. A general comparative analysis is proposed, considering other contributions which use Kalman filters, in which aspects of optimality, robustness, and chattering problems are discussed. In particular, an analysis of the computational effort is also reported. Laboratory experiments of the controlled system, which demonstrate promising behavior, are presented and discussed for exhaust valves of an engine.

A Hysteresis Hybrid Extended Kalman Filter as an Observer for Sensorless Valve Control in Camless Internal Combustion Engines

Abstract: Camless internal combustion engines offer improvements over traditional engines in terms of increased torque performance and fuel economy and of decreased emissions and pumping losses. The main goal of this project is to replace the camshaft system with electromagnetic actuators to control the intake and exhaust valves of internal combustion engines. Theoretically, electromagnetic valve actuators provide, with their control flexibility, the highest potential for improved efficiency. Sensorless control is one of the most important issues in implementations of this new technology. The main contribution of this paper is the proposal of a hysteresis hybrid observer to be applied for achieving a sensorless control. This observer consists of a combination of an extended Kalman filter with a hybrid automation. The proposed state-observation structure avoids bulky and complicated measurement systems, which is an important advancement for real-world applications. The introduced method is quite general and could be applied to other problems in which it is not feasible or affordable to obtain position and velocity measurements. In fact, in application with synchronous machines, such kind of an observer can represent a general approach to obtain a sensorless control. The proposed hysteresis strategy not only avoids chattering problems when the velocity is close to zero but also allows the use of unobservable sets and sets in which the observability level is too low to guarantee sufficient variation in the Kalman gains. The proposed structure consists of two models, each model containing two embedded switching conditions. The current is measured, and the position and the velocity of the electromagnetic valve are estimated. The effectiveness of the proposed method is demonstrated using measured data acquired from an experimental setup based on an innovative electromagnetic valve actuator.

An Antisaturating Adaptive Preaction and a Slide Surface to Achieve Soft Landing Control for Electromagnetic Actuators

Abstract: Real-control applications of any nature can be affected by saturation limits that generate windup. When saturation occurs in a device its performance deteriorates. Electromagnetic actuators for industrial applications are being utilized ever more frequently for positioning and tracking control problems. One of the most important requirements in tracking trajectories is to achieve a soft landing, which guarantees reliable functionality and a longer component life. This paper presents an application of a typical electromagnetic actuator through a hardware-in-the-loop structure in which a soft landing is required in the tracking trajectory. To avoid saturation, which prevents soft landings, a specific new control law is developed. The proposed technique is based on a cyclic adaptive current preaction combined with a sliding surface. The technique consists of building a control law so that the position of the valve at which its velocity assumes its minimum is as close as possible to the landing point. At this time point, the magnetic force compensates for the elastic force and the preaction component is switched off. An experimental setup using a hardware-in-the-loop to allow a pilot investigation, model validation, and testing before implementation is considered. Real measurements of the proposed method are shown.

Unscented Kalman Filterの計測への応用に関する研究

Abstract: where xt+1 is the position and orientation of the robot (with respect to a reference frame) at time t + 1, with (ξ, η) giving the x and y coordinates and θ the angle (with respect to the x-axis) that the robot is facing. The robot has two drive wheels, of radius r on an axle of length d. During time period t the right wheel is believed to rotate at a velocity of φRt and the left at a velocity of φLt. In this example, these velocities are fixed with φRt = 0.4 and φLt = 0.1. The state update function, F , calculates where the robot should be at each time point, given its previous position. However, in reality, there is some random fluctuation in the velocity of the wheels, for example, due to slippage. Therefore the actual position of the robot and the position given by equation F will differ. The magnitude of these random fluctuations is included in the model through Σx.

Unmanned Aerial Vehicles in Agriculture: A Review of Perspective of Platform, Control, and Applications

Abstract: For agricultural applications, regularized smart-farming solutions are being considered, including the use of unmanned aerial vehicles (UAVs). The UAVs combine information and communication technologies, robots, artificial intelligence, big data, and the Internet of Things. The agricultural UAVs are highly capable, and their use has expanded across all areas of agriculture, including pesticide and fertilizer spraying, seed sowing, and growth assessment and mapping. Accordingly, the market for agricultural UAVs is expected to continue growing with the related technologies. In this study, we consider the latest trends and applications of leading technologies related to agricultural UAVs, control technologies, equipment, and development. We discuss the use of UAVs in real agricultural environments. Furthermore, the future development of the agricultural UAVs and their challenges are presented.

Path Following of a Surface Vessel With Prescribed Performance in the Presence of Input Saturation and External Disturbances

Abstract: This paper presents a path following controller of a surface vessel with a prescribed performance in the presence of input saturation and external disturbances. Based on the three degrees-of-freedom model of the surface vessel, the designed backstepping control scheme features three functional parts, namely, guidance, attitude control, and velocity control. To guarantee that the position errors are confined within the prescribed convergence rates and maximum overshoot, a performance constrained guidance law is formulated with an error transformed function. Command filters are incorporated in the control subsections to limit the magnitude of the virtual controls and simultaneously avoid arduous computations involving their time derivatives. Subsequently, auxiliary systems that are governed by smooth switching functions are developed in an unprecedented manner to compensate for the saturation constraints on actuators. Nonlinear disturbance observers are concurrently introduced to estimate the unknown external disturbances for increasing system's robustness. It is demonstrated that under the proposed control, the prescribed transient and steady tracking performance bounds are never violated, and all closed-loop signals remain uniformly ultimately bounded, despite the presence of input saturation and disturbances. Results from a comparative simulation study illustrate the effectiveness and advantages of the proposed method.

Sensorless Control of Permanent Magnet Synchronous Machine Based on Second-Order Sliding-Mode Observer With Online Resistance Estimation

Abstract: In this paper, a supertwisting algorithm based second-order sliding-mode observer (STA-SMO) with online stator resistance ( $ R_{s}$ ) estimation for sensorless control of a nonsalient permanent magnet synchronous machine is proposed. A stator current observer is designed based on an STA to estimate the back electromotive force. A discontinuous sign function in the conventional SMO is replaced by a supertwisting function. The chattering problem, unavoidable in conventional SMO, is eliminated by reducing the amplitude of switching function of an STA-SMO. Meanwhile, a parallel online $ R_{s}$ estimation scheme is presented based on a modified SMO. Because mismatch between actual and set resistance may lead to estimation error and even system instability. The Lyapunov stability theorem is used to obtain the stable conditions of the proposed online $ R_{s}$ observer at both motoring and generating mode. With the help of online $ R_{s}$ observer, resistance uncertainties caused by temperature variation can be taken into account, which means robustness and stability of an STA-SMO can be improved. At the same time, higher position and speed estimation accuracy is obtained and operation range of sensorless control is extended. Finally, the proposed method is validated and compared with a conventional method by simulations and experiments.