The Experts below are selected from a list of 21609 Experts worldwide ranked by ideXlab platform
Henk Nijmeijer - One of the best experts on this subject based on the ideXlab platform.
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tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
Conference on Decision and Control, 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.
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CDC - Tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
2012 IEEE 51st IEEE Conference on Decision and Control (CDC), 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.
Jjb Benjamin Biemond - One of the best experts on this subject based on the ideXlab platform.
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tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
Conference on Decision and Control, 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.
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CDC - Tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
2012 IEEE 51st IEEE Conference on Decision and Control (CDC), 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.
Wei Shi - One of the best experts on this subject based on the ideXlab platform.
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Position Constraint loss for fashion landmark estimation
International Conference on Acoustics Speech and Signal Processing, 2020Co-Authors: Hong Liu, Meijia Song, Wei ShiAbstract:Fashion landmark estimation aims at locating functional key points of clothes, which has wide potential applications in electronic commerce. However, due to the occlusion and weak outline information, landmark estimation occurs outliers and duplicate detection problems. To alleviate these issues, we propose Position Constraint Loss (PCLoss) to constrain error landmark locations by utilizing the Position relationship of landmarks. Specifically, PCLoss adds a regularization term for each landmark to regularize their relative Positions, and it can be easily applied to both regression and heatmap based methods without extra computation during inference. Unlike existing approaches that propagate landmark information between feature layers by specific network structures, PCLoss introduces Position relations of landmarks in the label space without modifying the network structure. In addition, we leverage the skeleton-like relation of clothing to further strengthen Position Constraints between landmarks. Extensive experimental results on DeepFashion, FLD and FashionAI demonstrate that our methods can effectively increase the performance of mainstream frameworks by a large margin.
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ICASSP - Position Constraint Loss For Fashion Landmark Estimation
ICASSP 2020 - 2020 IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP), 2020Co-Authors: Hong Liu, Meijia Song, Wei ShiAbstract:Fashion landmark estimation aims at locating functional key points of clothes, which has wide potential applications in electronic commerce. However, due to the occlusion and weak outline information, landmark estimation occurs outliers and duplicate detection problems. To alleviate these issues, we propose Position Constraint Loss (PCLoss) to constrain error landmark locations by utilizing the Position relationship of landmarks. Specifically, PCLoss adds a regularization term for each landmark to regularize their relative Positions, and it can be easily applied to both regression and heatmap based methods without extra computation during inference. Unlike existing approaches that propagate landmark information between feature layers by specific network structures, PCLoss introduces Position relations of landmarks in the label space without modifying the network structure. In addition, we leverage the skeleton-like relation of clothing to further strengthen Position Constraints between landmarks. Extensive experimental results on DeepFashion, FLD and FashionAI demonstrate that our methods can effectively increase the performance of mainstream frameworks by a large margin.
N Van De Wouw - One of the best experts on this subject based on the ideXlab platform.
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tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
Conference on Decision and Control, 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.
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CDC - Tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
2012 IEEE 51st IEEE Conference on Decision and Control (CDC), 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.
W P M H Heemels - One of the best experts on this subject based on the ideXlab platform.
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tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
Conference on Decision and Control, 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.
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CDC - Tracking control of mechanical systems with a unilateral Position Constraint inducing dissipative impacts
2012 IEEE 51st IEEE Conference on Decision and Control (CDC), 2012Co-Authors: Jjb Benjamin Biemond, N Van De Wouw, W P M H Heemels, Ricardo G Sanfelice, Henk NijmeijerAbstract:In this paper, the tracking control problem is considered for mechanical systems with unilateral Constraints with dissipative impacts. In these systems, impacts are triggered at the exact moment when the Constraint becomes active. Typically, a small time mismatch is introduced between the impacts of the plant and the reference, even if this trajectory is arbitrarily close to the reference. Consequently, the Euclidean tracking error cannot behave stable in the sense of Lyapunov, such that standard tracking control approaches are unfeasible. However, desirable tracking behaviour does not imply that the Euclidean error vanishes asymptotically over time. We design continuous-time controllers that can handle the impact time mismatch and achieve accurate tracking of reference trajectories containing dissipative impacts for mechanical systems with a unilateral Constraint. The behaviour of the resulting closed-loop dynamical system is illustrated with an exemplary bouncing ball system.