Model-based versus model-free control designs for improving microalgae growth in a closed photobioreactor: Some preliminary comparisons

Controlling microalgae cultivation, i.e., a crucial industrial topic today, is a challenging task since the corresponding modeling is complex, highly uncertain and time-varying. A model-free control setting is therefore introduced in order to ensure a high growth of microalgae in a continuous closed photobioreactor. Computer simulations are displayed in order to compare this design to an input-output feedback linearizing control strategy, which is widely used in the academic literature on photobioreactors. They assess the superiority of the model-free standpoint both in terms of performances and implementation simplicity.Comment: The 24th Mediterranean Conference on Control and Automation (MED'16), Athens, Greece (June 21-24, 2016

Design of obstacle detection and avoidance system for GUANAY II AUV

Postprint (published version

Nonlinear control of dc/dc power converters with inherent current and power limitation

A nonlinear controller with an inherent current-limiting capability is presented in this paper for different types of dc/dc power converters (boost, buck-boost). The proposed controller is based on the idea of applying a dynamic virtual resistance in series with the inductor of the converter, which varies according to a nonlinear dynamical system. It is shown that the proposed approach acts independently from the converter parameters (inductance, capacitance) or the load and has a generic structure that can be used to achieve different regulation scenarios, e.g. voltage, current or power regulation. Based on the nonlinear model of the boost and the buck-boost converter, it is analytically proven that the inductor current remains always bounded below a given maximum value using input-to-state stability theory under a suitable choice of the controller parameters. Hence, the proposed control strategy offers an inherent protection property since the power of the converter is limited below a given value during transients or unrealistic power demands. Simulation results for both types of dc/dc converters are presented to verify the desired controller performance

Nonlinear control of a particular tilt-body MAV: The Roll&Fly

This paper details the design of a nonlinear controller for the Roll&Fly mode of a wheeled tiltbody micro air vehicle (MAV), developed at ISAE-SUPAERO, called the MAVion. The Roll&Fly mode consists in flying while rolling on walls or onto the ground to guide or increase the range of the MAV during detection or inspection missions. It therefore implies wall or ground mechanical interactions that calls for nontrivial control laws. Our approach consists in enabling a nonlinear obstacle-free attitude/height controller to adapt itself to wall interactions. The controller regulates the velocity and attitude of the drone by means of an approach based on backstepping and feedback linearization techniques. The attitude controller is parametrized by quaternion algebra to avoid orientation singularities

A novel structure design and control strategy for an aircraft active sidestick

This paper is concerned with a new design of an aircraft active sidestick based on Permanent Magnet Synchronous Machine (PMSM) and proposes an innovative robust control strategy based on an adaptive optimal sliding mode controller. Indeed, such an application requires high performance specifications which impose many constraints (torque, torques ripples, temperature). Here, a new design for the sidestick actuator is provided with a specific structure: a double airgap rotating one adapted to the considered process. Then, an optimization is performed to enhance the set of specifications of the PMSM w.r.t the aeronautical application. Also, a new adaptive optimal robust control for the designed actuator is provided based on the linear quadratic approach combined with the sliding mode control method. Then, an adaptive disturbances rejection is performed with the proposed strategy. Due to the considered design of the actuator (1/12 of a complete PMSM), a position control is achieved based on the LQRSliding mode approach to meet the required performances and to manage the plant parameter variation and load disturbances. Also, a varying parameter is used to adapt "on-line" the considered control to the varying level of disturbance that affect the system. First simulation results of the considered strategy applied to the newly designed actuator (compared to other strategies) proves the efficiency of the proposed solution for position control of the actuator and robustness considering load disturbances

Design a Robust Proportional-Derivative Gain-Scheduling Control for a Magnetic Levitation System

This study focuses on the design of a robust PD gain-scheduling controller (PD-GS-C) for an unstable SISO (single-input, single-output) magnetic levitation system with two electromagnets (MLS2EM). Magnetic levitation systems offer various advantages, including friction-free, reliable, fast, and cost-effective operations. However, due to their unstable and highly nonlinear nature, these systems require sophisticated feedback control techniques to ensure optimal performance and functionality. To address these challenges, in this study, we derive the nonlinear state-space mathematical model of the MLS2EM and linearize it around five different operating points. The PDGS-C controller aims to stabilize the system and improve steady-state control error. The strategy for obtaining the PD controller gains involves a parameter space technique, which specifies performance requirements. This technique results in ranges of proportional (KP) and derivative (KD) gains that are used by the PD-GS-C structure. To optimize the controller's performance further, we utilize the big bang-big crunch optimization technique (BB-BC) to determine the optimal PD gains within the specified ranges. The optimization process focuses on achieving optimal performance in terms of a specific performance index function. This function quantifies the system's time-domain step response criteria, which include minimizing overshoot percentage, settling time, and rising time. The index function is inversely proportional to the desired performance criteria, meaning that the goal is to maximize the index function to optimize the system's performance. To validate the effectiveness and viability of the proposed strategy, we conducts MATLAB simulations and real-time experiments. The simulations and experimental findings serve to demonstrate the controller's performance and verify its capabilities in stabilizing the MLS2EM magnetic levitation system

Investigation On The Influence Of Remanufacturing On Production Planning And Control – A Systematic Literature Review

Production planning and control (PPC) is one of the focal operational tasks of a company, and it is used to design logistics services in a target-orientated manner so that individual customer requirements can be fulfilled. However, existing PPC framework models are still based on the prevailing linear economic procedure (take - make - dispose). Due to customers' increasing interest in sustainability and growing regulatory pressure, the Circular Economy (CE) meets these changing conditions by closing material cycles, improving resource efficiency and extending product life cycles. However, for a company to guarantee a high logistics performance, the operational PPC must be adapted to this new economic model. To this end, it needs to be investigated whether and how the adaptation of circular strategies influences existing PPC processes. This paper focuses on the circular strategy of remanufacturing and its influence on different PPC-main tasks. The latter will be examined using a systematic literature review. Finally, the results of this analysis are compared with the Hanoverian Supply Chain Model as a PPC framework model. This comparison shows which PPC tasks are affected and which existing approaches have already been developed. Ultimately, these results provide the basis for developing a framework model for operational PPC regarding the CE

KENDALI PROSES TRANSISI HOVER TO CRUISE PADA PESAWAT TANPA AWAK VTOL FIXED WING

Hadirnya wahana tanpa awak atau Unmanned Aerial Vehicle (UAV) jenis VTOL (vertical take off and landing) fixed wing merupakan salah satu solusi untuk menerbangkan pesawat tanpa awak dengan area take off dan landing yang terbatas. Proses transisi dari hover to cruise memerlukan proses penalaan parameter yang mengatur proses itu dengan optimal untuk menghasilkan proses transisi yang optimal pula. Penelitian ini bertujuan untuk mengetahui parameter utama yang mengatur proses transisi hover to cruise yaitu duration of transition dan cruise throttle transition pada pesawat VTOL fixed wing Skywalker. Duration of transition yaitu waktu dimana proses transisi dilakukan dengan kondisi rotor quadcopter pemberi gaya lift dan rotor pusher berjalan bersama sama sehingga pesawat dapat bergerak melaju namun tetap dengan bantuan quad rotor pada saat mode tersebut untuk menghindari kondisi stall pesawat. Cruise throttle transition adalah nilai prosentase putaran motor pendorong pesawat pada saat proses transisi hover to cruise. Variabel respon yang diamati yaitu differential altitude, distance of transistion dan steady state time. Hasil pengujian menunjukkan bahwa dengan cruise throttle transition 100% menghasilkan proses transisi yang optimal dengan differential altitude minimal, distance of transition minimal dan waktu menuju steady state minimal. Dengan duration of transition 7, 8, 9 dan 10 detik dan cruise throttle transition sebesar 100% mimiliki steady state time 7 detik yang menunjukkan bahwa waktu yang dibutuhkan untuk menuju transisi optimal hanya 7 detik. Dengan duration of transition 7, 8, 9 dan 10 detik dan cruise throttle transition sebesar 75% mimiliki steady state time 7 detik pula, sama dengan kondisi cruise throttle transition sebesar 100%, namun dengan differential altitude dan distance of transition yang lebih besar

Theoretical and Experimental Collaborative Area Coverage Schemes Using Mobile Agents

This chapter is concerned with the development of collaborative control schemes for mobile ground robots for area coverage purposes. The simplest scheme assumes point omnidirectional robots with heterogeneous circular sensing patterns. Using information from their spatial neighbors, each robot (agent) computes its cell relying on the power diagram partitioning. If there is uncertainty in inferring the locations of these robots, the Additively Weighted Guaranteed Voronoi scheme is employed resulting in a rather conservative performance. The aforementioned schemes are enhanced by using a Voronoi-free coverage scheme that relies on the knowledge of any arbitrary sensing pattern employed by the agents. Experimental results are offered to highlight the efficiency of the suggested control laws

Dynamic parameters identification of a haptic interface for a helicopter flight simulator

Abstract. The haptic interface force feedback is one of the key factors for a reliable flight simulation. This paper addresses the design and control implementation of a simple joystick-like haptic interface to be used for a helicopter flight simulator. The expression of the haptic interface force is obtained by dynamic analysis of the haptic interface operation. This paper proposes a new strategy aiming at avoiding the use of an expansive and complex force/torque sensor. Accordingly, specific dynamic model is implemented by including Stribeck friction to describe the friction moment. Experimental data are processed as based on a genetic algorithm for identifying the dynamic parameters in the Stribeck friction model. This allows to obtain the friction moment parameters of the haptic interface, as well as the torque distribution due to gravity and the rotational inertia parameters of the haptic interface for the calculation of the haptic interface force. Experimental tests are carried out and results are used to validate the proposed dynamic model and dynamic parameter identification method and demonstrate the effectiveness of the proposed force feedback while using a cheap photoelectric sensor instead of an expansive force/torque sensor