Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915114
Rongxin Cui, Chenguang Yang, Y. Li, Sanjay K. Sharma
In this paper, the trajectory tracking control of the autonomous underwater vehicle (AUV) has been investigated in discrete time, for ease of digital computer calculation. A reinforcement learning scheme is employed using two neural networks, whereas the first one is to compensate for uncertainties for the controller, and the second one is to estimate the evaluation function, such that optimal tracking performance could be achieve for the AUV. Simulation results show that the errors convergence to a adjustable neighborhood around zero, and optimization has been achieved in the sense of reinforcement learning.
{"title":"Neural network based reinforcement learning control of autonomous underwater vehicles with control input saturation","authors":"Rongxin Cui, Chenguang Yang, Y. Li, Sanjay K. Sharma","doi":"10.1109/CONTROL.2014.6915114","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915114","url":null,"abstract":"In this paper, the trajectory tracking control of the autonomous underwater vehicle (AUV) has been investigated in discrete time, for ease of digital computer calculation. A reinforcement learning scheme is employed using two neural networks, whereas the first one is to compensate for uncertainties for the controller, and the second one is to estimate the evaluation function, such that optimal tracking performance could be achieve for the AUV. Simulation results show that the errors convergence to a adjustable neighborhood around zero, and optimization has been achieved in the sense of reinforcement learning.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127811848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915127
Hasan Basak, E. Prempain
This paper addresses the designs of low-order controllers for an Unmanned Aerial Vehicle (UAV) quadrotor using fixed and structured H∞ optimization techniques. Closed-loop performance, computational efficiency and tracking performance of low order controllers are compared with those of a standard full order H∞ controller.
{"title":"Low order H∞ controllers for a quadrotor UAV","authors":"Hasan Basak, E. Prempain","doi":"10.1109/CONTROL.2014.6915127","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915127","url":null,"abstract":"This paper addresses the designs of low-order controllers for an Unmanned Aerial Vehicle (UAV) quadrotor using fixed and structured H<sub>∞</sub> optimization techniques. Closed-loop performance, computational efficiency and tracking performance of low order controllers are compared with those of a standard full order H<sub>∞</sub> controller.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127967518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915112
Zhao Jun, Guoping Liu
This paper describes the design and implementation of an OMAP3530-based networked control system which has real-time image processing capability. It integrates an ARM core and a DSP core in the controller. The ARM core with Linux operating system is responsible for applying functional services and the DSP core is responsible for executing image processing algorithms. The due-core structure makes the novel controller available for advanced control and image processing so that the designed control system expands the application of the existed networked controllers to machine vision. Finally, a reliable application for vision-based mobile robot localization demonstrates the effectiveness of the designed system.
{"title":"Design and implementation of networked real-time control system with image processing capability","authors":"Zhao Jun, Guoping Liu","doi":"10.1109/CONTROL.2014.6915112","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915112","url":null,"abstract":"This paper describes the design and implementation of an OMAP3530-based networked control system which has real-time image processing capability. It integrates an ARM core and a DSP core in the controller. The ARM core with Linux operating system is responsible for applying functional services and the DSP core is responsible for executing image processing algorithms. The due-core structure makes the novel controller available for advanced control and image processing so that the designed control system expands the application of the existed networked controllers to machine vision. Finally, a reliable application for vision-based mobile robot localization demonstrates the effectiveness of the designed system.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121257049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915116
O. Elshazly, A. Abo-Ismail, H. S. Abbas, Z. Zyada
In this paper, a reduced order model of dynamic and drive models augmentation of a skid steering mobile robot is presented. Moreover, a Linear Quadratic Regulator (LQR) controller augmented with a feed-forward part is designed for controlling this reduced order model. The controller is simple in terms of design and implementation in comparison with complex nonlinear control schemes that are usually designed for this system. Moreover, it provides good performance for the plant comparable with a nonlinear controller based on the inverse dynamics which depends on the availability of an accurate model describing the system. Simulation results are included.
{"title":"Skid steering mobile robot modeling and control","authors":"O. Elshazly, A. Abo-Ismail, H. S. Abbas, Z. Zyada","doi":"10.1109/CONTROL.2014.6915116","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915116","url":null,"abstract":"In this paper, a reduced order model of dynamic and drive models augmentation of a skid steering mobile robot is presented. Moreover, a Linear Quadratic Regulator (LQR) controller augmented with a feed-forward part is designed for controlling this reduced order model. The controller is simple in terms of design and implementation in comparison with complex nonlinear control schemes that are usually designed for this system. Moreover, it provides good performance for the plant comparable with a nonlinear controller based on the inverse dynamics which depends on the availability of an accurate model describing the system. Simulation results are included.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115767898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915126
M. Z. Shah, M. Ozgoren, R. Samar
This paper presents a sliding mode based longitudinal guidance scheme for Unmanned Aerial Vehicles (UAVs). A nonlinear sliding surface is proposed here for altitude control of UAVs. Longitudinal guidance law based on traditional linear sliding surface cannot provide good performance for both large and small errors in altitude, hence a non-linear surface is proposed here. The proposed sliding surface gives good performance in level cruising as well as during climb/decent phase. The Proposed guidance scheme is implemented on a 6-degrees-of-freedom (6-dof) nonlinear simulation of a UAV, and different scenarios of climb, decent and level cruise phase is simulated.
{"title":"Sliding mode based longitudinal guidance of UAVs","authors":"M. Z. Shah, M. Ozgoren, R. Samar","doi":"10.1109/CONTROL.2014.6915126","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915126","url":null,"abstract":"This paper presents a sliding mode based longitudinal guidance scheme for Unmanned Aerial Vehicles (UAVs). A nonlinear sliding surface is proposed here for altitude control of UAVs. Longitudinal guidance law based on traditional linear sliding surface cannot provide good performance for both large and small errors in altitude, hence a non-linear surface is proposed here. The proposed sliding surface gives good performance in level cruising as well as during climb/decent phase. The Proposed guidance scheme is implemented on a 6-degrees-of-freedom (6-dof) nonlinear simulation of a UAV, and different scenarios of climb, decent and level cruise phase is simulated.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130292333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915196
Abdullah T. Elgammal, A. A. Abouelsouda, Samy F. M. Assal
This paper presents an Exact FeedForward Linearization controller combined with fuzzy-based gain scheduling for single DOF magnetic ball levitation system. The proposed method improves the previously reported techniques in terms of transient response behavior and tracking error. A Luenberger State estimator for the nonlinear/uncertain plant is implemented. Finally, the control law and the estimator are combined and applied experimentally to the magnetic ball levitation system. The results show the effectiveness and the robustness of this scheme regarding the increase of the dynamic range of the tracked signals and the presence of payload variation.
{"title":"Fuzzy logic-based gain scheduling of Exact Feedforward Linearization controller for magnetic ball levitation system","authors":"Abdullah T. Elgammal, A. A. Abouelsouda, Samy F. M. Assal","doi":"10.1109/CONTROL.2014.6915196","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915196","url":null,"abstract":"This paper presents an Exact FeedForward Linearization controller combined with fuzzy-based gain scheduling for single DOF magnetic ball levitation system. The proposed method improves the previously reported techniques in terms of transient response behavior and tracking error. A Luenberger State estimator for the nonlinear/uncertain plant is implemented. Finally, the control law and the estimator are combined and applied experimentally to the magnetic ball levitation system. The results show the effectiveness and the robustness of this scheme regarding the increase of the dynamic range of the tracked signals and the presence of payload variation.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131101238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915211
M. Coombes, William Eaton, O. McAree, Wen‐Hua Chen
This paper describes the development of a system for autonomous vehicle testing, utilising conventional network infrastructure for communication and control; allowing simultaneous control of multiple vehicles of differing vehicle types. A basic level of autonomy is achieved through the use of an Arduino based commercial autopilot (ArduPilot), which also allows for remote vehicle control via MAVLink protocol commands given through serial communication. Traditionally messages are sent using point-to-point wireless serial modems. As these are restricted in terms of bandwidth and flexibility, an improved set-up is suggested, where an embedded computer system is attached to each vehicle. A custom written Node.js program (MAVNode) is then used to encode and decode MAVLink messages onboard allowing communication over a Local Area Network via Wi-Fi, A selection of hardware configurations are discussed, including the use of conventional Wi-Fi and long range Ubiquiti airMAX wireless routers. Both software and hardware in the loop testing is discussed, in addition to the ability to to perform control from Matlab/Simulink. With all the infrastructure in place, algorithms can be rapidly prototyped. As an example use of the system, a quad-rotor visually tracks a robot while using a remote Matlab installation for image processing and control.
{"title":"Development of a generic network enabled autonomous vehicle system","authors":"M. Coombes, William Eaton, O. McAree, Wen‐Hua Chen","doi":"10.1109/CONTROL.2014.6915211","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915211","url":null,"abstract":"This paper describes the development of a system for autonomous vehicle testing, utilising conventional network infrastructure for communication and control; allowing simultaneous control of multiple vehicles of differing vehicle types. A basic level of autonomy is achieved through the use of an Arduino based commercial autopilot (ArduPilot), which also allows for remote vehicle control via MAVLink protocol commands given through serial communication. Traditionally messages are sent using point-to-point wireless serial modems. As these are restricted in terms of bandwidth and flexibility, an improved set-up is suggested, where an embedded computer system is attached to each vehicle. A custom written Node.js program (MAVNode) is then used to encode and decode MAVLink messages onboard allowing communication over a Local Area Network via Wi-Fi, A selection of hardware configurations are discussed, including the use of conventional Wi-Fi and long range Ubiquiti airMAX wireless routers. Both software and hardware in the loop testing is discussed, in addition to the ability to to perform control from Matlab/Simulink. With all the infrastructure in place, algorithms can be rapidly prototyped. As an example use of the system, a quad-rotor visually tracks a robot while using a remote Matlab installation for image processing and control.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122473597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915210
M. Nohr, T. Utz, K. Graichen
Semi-batch processes are gaining further importance in the chemical industry, due to the trend to produce more speciality products with higher margins. Besides a constantly high product quality, a maximum space-time-yield is a principal goal of process control for semi-batch processes. This requires to drive the process along its limits, which often is impossible with standard PID control schemes. More sophisticated control methodologies potentially allow for a maximisation of the space-time-yield while keeping the product quality high. However the scientific development and test of such methodologies is often conducted using very simplified reactor models, which may allow for a demonstration of the basic feasibility but neglect additional effects, which hamper the transfer to industrial processes. Therefore a more detailed model of a semi-batch process, suitable for the development and test of control schemes is presented in this contribution. Using this model, a simulation study elucidates the limitations of classical temperature control concepts when aiming for a maximisation of the space-time-yield.
{"title":"Kinetic modelling of an industrial semi-batch alkoxylation reactor for control studies","authors":"M. Nohr, T. Utz, K. Graichen","doi":"10.1109/CONTROL.2014.6915210","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915210","url":null,"abstract":"Semi-batch processes are gaining further importance in the chemical industry, due to the trend to produce more speciality products with higher margins. Besides a constantly high product quality, a maximum space-time-yield is a principal goal of process control for semi-batch processes. This requires to drive the process along its limits, which often is impossible with standard PID control schemes. More sophisticated control methodologies potentially allow for a maximisation of the space-time-yield while keeping the product quality high. However the scientific development and test of such methodologies is often conducted using very simplified reactor models, which may allow for a demonstration of the basic feasibility but neglect additional effects, which hamper the transfer to industrial processes. Therefore a more detailed model of a semi-batch process, suitable for the development and test of control schemes is presented in this contribution. Using this model, a simulation study elucidates the limitations of classical temperature control concepts when aiming for a maximisation of the space-time-yield.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125025123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915148
I. Vitanov, N. Aouf
In order to ensure safe operation and meet reliability standards at a safety-critical level, instrument failures have to be robustly handled through effective fault diagnosis. A popular approach to fault detection for non-linear systems is the extended Kalman filter (EKF). It has, however, been shown to lack robustness in the face of non-Gaussian noise disturbances and modelling errors. An alternative to the EKF, the extended H∞ (EHF) filter is capable of robust estimation even in the presence of coloured noise; though, modelled on the EKF, it does inherit certain of its shortcomings. A recent addition to the H∞ family of filters, the unscented H∞ filter (UHF) promises both robustness and excellent estimation performance in non-linear, non-Gaussian settings. This paper presents arguably the first application of the UHF to an FDI task: sensor fault detection and isolation (FDI) in a strap-down inertial navigation system (INS) of the type commonly mounted on smaller unmanned aircraft. We apply the UHF in a bank of dedicated observers within an analytical redundancy framework. Results are comparable to the EKF under a Gaussianity assumption.
{"title":"Fault detection and isolation in an inertial navigation system using a bank of unscented H∞ filters","authors":"I. Vitanov, N. Aouf","doi":"10.1109/CONTROL.2014.6915148","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915148","url":null,"abstract":"In order to ensure safe operation and meet reliability standards at a safety-critical level, instrument failures have to be robustly handled through effective fault diagnosis. A popular approach to fault detection for non-linear systems is the extended Kalman filter (EKF). It has, however, been shown to lack robustness in the face of non-Gaussian noise disturbances and modelling errors. An alternative to the EKF, the extended H∞ (EHF) filter is capable of robust estimation even in the presence of coloured noise; though, modelled on the EKF, it does inherit certain of its shortcomings. A recent addition to the H∞ family of filters, the unscented H∞ filter (UHF) promises both robustness and excellent estimation performance in non-linear, non-Gaussian settings. This paper presents arguably the first application of the UHF to an FDI task: sensor fault detection and isolation (FDI) in a strap-down inertial navigation system (INS) of the type commonly mounted on smaller unmanned aircraft. We apply the UHF in a bank of dedicated observers within an analytical redundancy framework. Results are comparable to the EKF under a Gaussianity assumption.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124228960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-07-09DOI: 10.1109/CONTROL.2014.6915215
J. Dunthorne, Wen‐Hua Chen, S. Dunnett
This paper proposes a method for estimating the amount of time until the point of closest approach (TPCA) between two aircraft. A range of simple methods which use derivatives to estimate the time to collision are analysed. These methods are only accurate when the angle subtended between the direction of the relative velocity vector, and the bearing of the intruder aircraft is small. An extended method is developed which calculates the exact TPCA from relative distance and bearing measurements. Representative levels of Gaussian white noise are introduced to the core equation variables for both the derivative and extended methods. It is found that as we increase the value of θ, the extended method's accuracy increases beyond that of the derivative method. A fusion algorithm is developed to switch between methods and is shown to perform well for a range of conflicts. When the relative velocity between the two aircraft is small, the signal to noise ratio on the relative velocity variable reduces causing large errors to the TPCA estimation. It is therefore concluded that at a certain relative velocity threshold, Vk (dependant on sensor and filter performance) both the derivative and extended TPCA estimation methods would become undesirable as risk estimators. It is suggested that in these situations distance could be better to use since it can be measured directly.
{"title":"Estimation of time to point of closest approach for collision avoidance and separation systems","authors":"J. Dunthorne, Wen‐Hua Chen, S. Dunnett","doi":"10.1109/CONTROL.2014.6915215","DOIUrl":"https://doi.org/10.1109/CONTROL.2014.6915215","url":null,"abstract":"This paper proposes a method for estimating the amount of time until the point of closest approach (TPCA) between two aircraft. A range of simple methods which use derivatives to estimate the time to collision are analysed. These methods are only accurate when the angle subtended between the direction of the relative velocity vector, and the bearing of the intruder aircraft is small. An extended method is developed which calculates the exact TPCA from relative distance and bearing measurements. Representative levels of Gaussian white noise are introduced to the core equation variables for both the derivative and extended methods. It is found that as we increase the value of θ, the extended method's accuracy increases beyond that of the derivative method. A fusion algorithm is developed to switch between methods and is shown to perform well for a range of conflicts. When the relative velocity between the two aircraft is small, the signal to noise ratio on the relative velocity variable reduces causing large errors to the TPCA estimation. It is therefore concluded that at a certain relative velocity threshold, Vk (dependant on sensor and filter performance) both the derivative and extended TPCA estimation methods would become undesirable as risk estimators. It is suggested that in these situations distance could be better to use since it can be measured directly.","PeriodicalId":269044,"journal":{"name":"2014 UKACC International Conference on Control (CONTROL)","volume":"17 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120981914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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