Nahuel Deniz - Academia.edu (original) (raw)
Papers by Nahuel Deniz
Springer eBooks, Dec 31, 2022
arXiv (Cornell University), Jun 25, 2019
In this article we present a unified framework based on receding horizon techniques that can be u... more In this article we present a unified framework based on receding horizon techniques that can be used to design the three tasks (guidance, navigation and path-planning) which are involved in the autonomy of unmanned vehicles. This tasks are solved using model predictive control and moving horizon estimation techniques, which allows us to include physical and dynamical constraints at the design stage, thus leading to optimal and feasible results. In order to demonstrate the capabilities of the proposed framework, we have used Gazebo simulator in order to drive a Jackal unmanned ground vehicle (UGV) along a desired path computed by the pathplanning task. The results we have obtained are successful as the estimation and guidance errors are small and the Jackal UGV is able to follow the desired path satisfactorily and it is also capable to avoid the obstacles which are in its way.
arXiv (Cornell University), Jun 24, 2019
In the present work, an optimization-based algorithm for state estimation under model uncertainty... more In the present work, an optimization-based algorithm for state estimation under model uncertainty and bounded disturbances is presented. In order to avoid to solve a non-convex optimization problem, model and state estimation problems are divided into two convex formulations which are solved within a fixed-point iteration scheme with standard available solvers. Guaranty of robust global stability are given for the case of bounded disturbances and uncertainty, and convergence to the true system and vector state are given for the case of vanishing disturbances.
Skid-steer vehicles are one of the most popular configuration of autonomous ground vehicles (AGVs... more Skid-steer vehicles are one of the most popular configuration of autonomous ground vehicles (AGVs). Their mechanical simplicity provides researchers and developers with an easy to build vehicle that can perform complicated tasks either in outdoor or indoor scenarios. However, the process of building an AGV usually requires to spend a lot of time solving problems that are already solved. This work focuses on the process required to make a working AGV –the Hibachi– compatible with Robot Operating System (ROS). We mainly describe and explain the tasks of developing the required software and device drivers to implement ros_control on the existing hardware, allowing easier sensor integration and providing a standarized testbed for AGV research.
International Journal of Robust and Nonlinear Control
SummaryIn this work, we address the output–feedback control problem for nonlinear systems under b... more SummaryIn this work, we address the output–feedback control problem for nonlinear systems under bounded disturbances using a moving horizon approach. The controller is posed as an optimisation‐based problem that simultaneously estimates the state trajectory and computes future control inputs. It minimizes a criterion that involves finite backward and forward horizons with respect to the unknown initial state, measurement noises and control input variables. The main novelty of this work relies on linking the lengths of the forward and backward windows with the closed‐loop stability, assuming detectability and decoding sufficient conditions to assure system stabilizability. It leads to a formulation that does not require to be a Control Lyapunov Function for the terminal cost of the controller. Simulation examples are carried out to compare the performance of solving simultaneously and independently the estimation and control problems. Furthermore, the examples show how the controller...
Computers and Electronics in Agriculture, 2022
Springer eBooks, Nov 9, 2022
2017 XVII Workshop on Information Processing and Control (RPIC), 2017
This work provides a comparative review of three different numerical methods generally used to di... more This work provides a comparative review of three different numerical methods generally used to discretize continuous-time non-linear equations appearing in model predictive control problems: direct multiple shooting, direct collocation and successive linearizations. An overview of the characteristics of each method is given and the performance of each method is evaluated through the simulation of two test cases.
This paper introduces an adaptive polytopic estimator design for nonlinear systems under bounded ... more This paper introduces an adaptive polytopic estimator design for nonlinear systems under bounded disturbances combining moving horizon and dual estimation techniques. It extends the moving horizon estimation results for LTI systems to polytopic LPV systems. The design and necessary conditions to guarantee the robust stability and convergence to the true state and parameters for the case of bounded disturbances and convergence to the true system and state are given for the vanishing disturbances.
ArXiv, 2019
In this article we present a unified framework based on receding horizon techniques that can be u... more In this article we present a unified framework based on receding horizon techniques that can be used to design the three tasks (guidance, navigation and path-planning) which are involved in the autonomy of unmanned vehicles. This tasks are solved using model predictive control and moving horizon estimation techniques, which allows us to include physical and dynamical constraints at the design stage, thus leading to optimal and feasible results. In order to demonstrate the capabilities of the proposed framework, we have used Gazebo simulator in order to drive a Jackal unmanned ground vehicle (UGV) along a desired path computed by the path-planning task. The results we have obtained are successful as the estimation and guidance errors are small and the Jackal UGV is able to follow the desired path satisfactorily and it is also capable to avoid the obstacles which are in its way.
Mecánica Computacional, Nov 24, 2019
In this article we propose to use receding horizon strategies, like model predictive control (MPC... more In this article we propose to use receding horizon strategies, like model predictive control (MPC) and moving horizon estimation (MHE), to design guidance, navigation and path-planning tasks, which play an essential role in autonomy of unmanned vehicles. As we propose to design these tasks using MPC and MHE, the physical and dynamical constraints can be included at the design stage, thus leading to optimal and feasible results. In order to evaluate the performance of the proposed framework, we have used Gazebo simulator in order to drive a Jackal unmanned ground vehicle (UGV) along a desired path computed by the path-planning module. The results we have obtained are successful as the estimation and guidance errors are small and the Jackal UGV is able to follow the desired path satisfactorily and it is also capable to avoid the obstacles which are in its way.
2021 XIX Workshop on Information Processing and Control (RPIC), 2021
In this paper, we propose a tuning mechanism for the arrival cost (AC) of nonlinear moving horizo... more In this paper, we propose a tuning mechanism for the arrival cost (AC) of nonlinear moving horizon estimators (NMHE) with quadratic stage cost (SC) that are robustly global asymptotically stable (RGAS). We consider general detectable nonlinear systems subject to bounded disturbances that are a priori unknown. Based on the robust stability results for NMHE, which state an optimal relation between the eigenvalues of the AC and SC weighting matrices in the sense of minimising the estimation error, we propose a mechanism that preserves the optimal conditioning number of the AC in every sampling time. The performance of the proposed mechanism is illustrated through simulation studies.
ArXiv, 2019
In the present work, an optimization-based algorithm for state estimation under model uncertainty... more In the present work, an optimization-based algorithm for state estimation under model uncertainty and bounded disturbances is presented. In order to avoid to solve a non-convex optimization problem, model and state estimation problems are divided into two convex formulations which are solved within a fixed-point iteration scheme with standard available solvers. Guaranty of robust global stability are given for the case of bounded disturbances and uncertainty, and convergence to the true system and vector state are given for the case of vanishing disturbances.
ArXiv, 2019
In this work, we address the output--feedback control problem for nonlinear systems under bounded... more In this work, we address the output--feedback control problem for nonlinear systems under bounded disturbances using a moving horizon approach. The controller is posed as an optimization-based problem that simultaneously estimates the state trajectory and computes future control inputs. It minimizes a criterion that involves finite forward and backward horizon with respect the unknown initial state, measurement noises and control input variables and it is maximized with respect the unknown future disturbances. Although simultaneous state estimation and control approaches are already available in the literature, the novelty of this work relies on linking the lengths of the forward and backward windows with the closed-loop stability, assuming detectability and decoding sufficient conditions to assure system stabilizability. Simulation examples are carried out to compare the performance of simultaneous and independent estimation and control approaches as well as to show the effects of ...
2017 XVII Workshop on Information Processing and Control (RPIC), 2017
This work focuses on the study of an agricultural articulated vehicle which carries an implement ... more This work focuses on the study of an agricultural articulated vehicle which carries an implement (such as a plow or a harvester). The derivation of a mathematical model of its kinematics is presented, and then the methodology of model predictive control is used in order to have the implement follow a predefined trajectory. The performance of the system and the corresponding controller is ilustrated through numerical simulations, which yield satisfactory results.
Revista Tecnología y Ciencia, 2019
El presente trabajo lleva adelante un análisis de un tractor articulado con dirección delantera a... more El presente trabajo lleva adelante un análisis de un tractor articulado con dirección delantera acoplado a un implemento agrícola (como ser una fumigadora o una sembradora). Se desarrolla aquí el modelo de este sistema, en primer lugar en términos cinemáticos y luego en términos dinámicos. Utilizando la técnica de control predictivo, se calculan las acciones de control que permiten al implemento recorrer una trayectoria de referencia. Se emplean simulaciones numéricas para ilustrar el comportamiento del sistema y del controlador implementado.
Computers and Electronics in Agriculture, 2017
Estimating forage intake and monitoring behavior of grazing livestock are difficult tasks. Real-t... more Estimating forage intake and monitoring behavior of grazing livestock are difficult tasks. Real-time detection and classification of events like chew, bite and chew-bite are necessary to estimate that information. It is well-known that acoustic monitoring is one of the best ways to characterize feeding behavior in ruminants. Although several methods have been developed to detect and classify events, their implementation is restricted to desktop computers, fact that confines their application to off-line analysis of a reduced number of animals. In this work, we present the design and implementation of an electronic system specifically developed for real-time monitoring of feeding patterns in dairy cows. The system is based on an embedded circuit to process the sound produced by the animal in order to detect, classify and quantify events of ruminant feeding behavior. The system implements an algorithm recently developed, which was adapted to be executed on a microcontroller-based electronic system. Only the results of sound analysis are stored in flash memory units. In addition to sound information, data from a GPS receiver is also stored, thus building a package of information. A microcontroller with power management technology, combined with a high-efficiency harvesting power supply and power management firmware, enables long operational time (more than five days of continuous operation). The system was evaluated using audio signals derived from the feeding activity of dairy cows that were acquired under normal operational conditions. The system correctly detected 92% of the events (i.e. considering them as possible events without making a classification). When the three types of events (i.e. chew, bite and chew-bite) were considered for classification, the recognition rate was about 78%. These results were obtained using reference labels provided by experts in ruminant ingestive behavior. The technology presented within this publication is protected under the international patent application PCT/IB2015/053721.
Springer eBooks, Dec 31, 2022
arXiv (Cornell University), Jun 25, 2019
In this article we present a unified framework based on receding horizon techniques that can be u... more In this article we present a unified framework based on receding horizon techniques that can be used to design the three tasks (guidance, navigation and path-planning) which are involved in the autonomy of unmanned vehicles. This tasks are solved using model predictive control and moving horizon estimation techniques, which allows us to include physical and dynamical constraints at the design stage, thus leading to optimal and feasible results. In order to demonstrate the capabilities of the proposed framework, we have used Gazebo simulator in order to drive a Jackal unmanned ground vehicle (UGV) along a desired path computed by the pathplanning task. The results we have obtained are successful as the estimation and guidance errors are small and the Jackal UGV is able to follow the desired path satisfactorily and it is also capable to avoid the obstacles which are in its way.
arXiv (Cornell University), Jun 24, 2019
In the present work, an optimization-based algorithm for state estimation under model uncertainty... more In the present work, an optimization-based algorithm for state estimation under model uncertainty and bounded disturbances is presented. In order to avoid to solve a non-convex optimization problem, model and state estimation problems are divided into two convex formulations which are solved within a fixed-point iteration scheme with standard available solvers. Guaranty of robust global stability are given for the case of bounded disturbances and uncertainty, and convergence to the true system and vector state are given for the case of vanishing disturbances.
Skid-steer vehicles are one of the most popular configuration of autonomous ground vehicles (AGVs... more Skid-steer vehicles are one of the most popular configuration of autonomous ground vehicles (AGVs). Their mechanical simplicity provides researchers and developers with an easy to build vehicle that can perform complicated tasks either in outdoor or indoor scenarios. However, the process of building an AGV usually requires to spend a lot of time solving problems that are already solved. This work focuses on the process required to make a working AGV –the Hibachi– compatible with Robot Operating System (ROS). We mainly describe and explain the tasks of developing the required software and device drivers to implement ros_control on the existing hardware, allowing easier sensor integration and providing a standarized testbed for AGV research.
International Journal of Robust and Nonlinear Control
SummaryIn this work, we address the output–feedback control problem for nonlinear systems under b... more SummaryIn this work, we address the output–feedback control problem for nonlinear systems under bounded disturbances using a moving horizon approach. The controller is posed as an optimisation‐based problem that simultaneously estimates the state trajectory and computes future control inputs. It minimizes a criterion that involves finite backward and forward horizons with respect to the unknown initial state, measurement noises and control input variables. The main novelty of this work relies on linking the lengths of the forward and backward windows with the closed‐loop stability, assuming detectability and decoding sufficient conditions to assure system stabilizability. It leads to a formulation that does not require to be a Control Lyapunov Function for the terminal cost of the controller. Simulation examples are carried out to compare the performance of solving simultaneously and independently the estimation and control problems. Furthermore, the examples show how the controller...
Computers and Electronics in Agriculture, 2022
Springer eBooks, Nov 9, 2022
2017 XVII Workshop on Information Processing and Control (RPIC), 2017
This work provides a comparative review of three different numerical methods generally used to di... more This work provides a comparative review of three different numerical methods generally used to discretize continuous-time non-linear equations appearing in model predictive control problems: direct multiple shooting, direct collocation and successive linearizations. An overview of the characteristics of each method is given and the performance of each method is evaluated through the simulation of two test cases.
This paper introduces an adaptive polytopic estimator design for nonlinear systems under bounded ... more This paper introduces an adaptive polytopic estimator design for nonlinear systems under bounded disturbances combining moving horizon and dual estimation techniques. It extends the moving horizon estimation results for LTI systems to polytopic LPV systems. The design and necessary conditions to guarantee the robust stability and convergence to the true state and parameters for the case of bounded disturbances and convergence to the true system and state are given for the vanishing disturbances.
ArXiv, 2019
In this article we present a unified framework based on receding horizon techniques that can be u... more In this article we present a unified framework based on receding horizon techniques that can be used to design the three tasks (guidance, navigation and path-planning) which are involved in the autonomy of unmanned vehicles. This tasks are solved using model predictive control and moving horizon estimation techniques, which allows us to include physical and dynamical constraints at the design stage, thus leading to optimal and feasible results. In order to demonstrate the capabilities of the proposed framework, we have used Gazebo simulator in order to drive a Jackal unmanned ground vehicle (UGV) along a desired path computed by the path-planning task. The results we have obtained are successful as the estimation and guidance errors are small and the Jackal UGV is able to follow the desired path satisfactorily and it is also capable to avoid the obstacles which are in its way.
Mecánica Computacional, Nov 24, 2019
In this article we propose to use receding horizon strategies, like model predictive control (MPC... more In this article we propose to use receding horizon strategies, like model predictive control (MPC) and moving horizon estimation (MHE), to design guidance, navigation and path-planning tasks, which play an essential role in autonomy of unmanned vehicles. As we propose to design these tasks using MPC and MHE, the physical and dynamical constraints can be included at the design stage, thus leading to optimal and feasible results. In order to evaluate the performance of the proposed framework, we have used Gazebo simulator in order to drive a Jackal unmanned ground vehicle (UGV) along a desired path computed by the path-planning module. The results we have obtained are successful as the estimation and guidance errors are small and the Jackal UGV is able to follow the desired path satisfactorily and it is also capable to avoid the obstacles which are in its way.
2021 XIX Workshop on Information Processing and Control (RPIC), 2021
In this paper, we propose a tuning mechanism for the arrival cost (AC) of nonlinear moving horizo... more In this paper, we propose a tuning mechanism for the arrival cost (AC) of nonlinear moving horizon estimators (NMHE) with quadratic stage cost (SC) that are robustly global asymptotically stable (RGAS). We consider general detectable nonlinear systems subject to bounded disturbances that are a priori unknown. Based on the robust stability results for NMHE, which state an optimal relation between the eigenvalues of the AC and SC weighting matrices in the sense of minimising the estimation error, we propose a mechanism that preserves the optimal conditioning number of the AC in every sampling time. The performance of the proposed mechanism is illustrated through simulation studies.
ArXiv, 2019
In the present work, an optimization-based algorithm for state estimation under model uncertainty... more In the present work, an optimization-based algorithm for state estimation under model uncertainty and bounded disturbances is presented. In order to avoid to solve a non-convex optimization problem, model and state estimation problems are divided into two convex formulations which are solved within a fixed-point iteration scheme with standard available solvers. Guaranty of robust global stability are given for the case of bounded disturbances and uncertainty, and convergence to the true system and vector state are given for the case of vanishing disturbances.
ArXiv, 2019
In this work, we address the output--feedback control problem for nonlinear systems under bounded... more In this work, we address the output--feedback control problem for nonlinear systems under bounded disturbances using a moving horizon approach. The controller is posed as an optimization-based problem that simultaneously estimates the state trajectory and computes future control inputs. It minimizes a criterion that involves finite forward and backward horizon with respect the unknown initial state, measurement noises and control input variables and it is maximized with respect the unknown future disturbances. Although simultaneous state estimation and control approaches are already available in the literature, the novelty of this work relies on linking the lengths of the forward and backward windows with the closed-loop stability, assuming detectability and decoding sufficient conditions to assure system stabilizability. Simulation examples are carried out to compare the performance of simultaneous and independent estimation and control approaches as well as to show the effects of ...
2017 XVII Workshop on Information Processing and Control (RPIC), 2017
This work focuses on the study of an agricultural articulated vehicle which carries an implement ... more This work focuses on the study of an agricultural articulated vehicle which carries an implement (such as a plow or a harvester). The derivation of a mathematical model of its kinematics is presented, and then the methodology of model predictive control is used in order to have the implement follow a predefined trajectory. The performance of the system and the corresponding controller is ilustrated through numerical simulations, which yield satisfactory results.
Revista Tecnología y Ciencia, 2019
El presente trabajo lleva adelante un análisis de un tractor articulado con dirección delantera a... more El presente trabajo lleva adelante un análisis de un tractor articulado con dirección delantera acoplado a un implemento agrícola (como ser una fumigadora o una sembradora). Se desarrolla aquí el modelo de este sistema, en primer lugar en términos cinemáticos y luego en términos dinámicos. Utilizando la técnica de control predictivo, se calculan las acciones de control que permiten al implemento recorrer una trayectoria de referencia. Se emplean simulaciones numéricas para ilustrar el comportamiento del sistema y del controlador implementado.
Computers and Electronics in Agriculture, 2017
Estimating forage intake and monitoring behavior of grazing livestock are difficult tasks. Real-t... more Estimating forage intake and monitoring behavior of grazing livestock are difficult tasks. Real-time detection and classification of events like chew, bite and chew-bite are necessary to estimate that information. It is well-known that acoustic monitoring is one of the best ways to characterize feeding behavior in ruminants. Although several methods have been developed to detect and classify events, their implementation is restricted to desktop computers, fact that confines their application to off-line analysis of a reduced number of animals. In this work, we present the design and implementation of an electronic system specifically developed for real-time monitoring of feeding patterns in dairy cows. The system is based on an embedded circuit to process the sound produced by the animal in order to detect, classify and quantify events of ruminant feeding behavior. The system implements an algorithm recently developed, which was adapted to be executed on a microcontroller-based electronic system. Only the results of sound analysis are stored in flash memory units. In addition to sound information, data from a GPS receiver is also stored, thus building a package of information. A microcontroller with power management technology, combined with a high-efficiency harvesting power supply and power management firmware, enables long operational time (more than five days of continuous operation). The system was evaluated using audio signals derived from the feeding activity of dairy cows that were acquired under normal operational conditions. The system correctly detected 92% of the events (i.e. considering them as possible events without making a classification). When the three types of events (i.e. chew, bite and chew-bite) were considered for classification, the recognition rate was about 78%. These results were obtained using reference labels provided by experts in ruminant ingestive behavior. The technology presented within this publication is protected under the international patent application PCT/IB2015/053721.