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ANALYSIS OF THE KINEMATIC AND DYNAMIC BEHAVIOR OF THE SHOULDER MECHANISM

JOURNAL OF BIOMECHANICS 1994年第5期27卷 527-550页

作者： VANDERHELM, FCT Man-Machine Systems Group Laboratory for Measurement and Control Department of Mechanical Engineering Delft University of Technology Delft The Netherlands

A finite element musculoskeletal model of the shoulder mechanism consisting of the thorax, clavicula, scapula and humerus has been used for analysis of the kinematic and dynamic behavior. The model includes 16 muscles, three joints, three extracapsular ligaments and the motion constraints of the scapulothoracic gliding plane which turns the shoulder girdle into a closed-chain mechanism. Simulations are inverse dynamic. Input variables are the positions of the shoulder girdle and humerus which have been recorded in 10 subjects during unloaded and loaded humeral abduction and anteflexion. Comparisons of muscle force predictions and EMG recordings are hampered by the unknown force-length relationship and the length dependency of EMG amplitude. It is concluded that EMG amplitude cannot be used for validation of complex musculoskeletal models. Muscle function is analyzed with help of a force and moment balance of the three joints. The moment balance includes the contributions of ligaments and the reaction forces at the scapulothoracic gliding plane. The scapulothoracic gliding plane is very important for the motions and the stabilization of the shoulder girdle. The direction and magnitude of joint reaction forces are calculated as well. It is concluded that the model provides good insight into the mechanics of the shoulder mechanism and that it enables an analysis of the function of morphological structures.

关键词： Biomechanics

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DERIVATION OF THE NON-LINEAR SCHRODINGER-EQUATION FROM STOCHASTIC OPTIMAL-control

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INTERNATIONAL JOURNAL OF control 1989年第3期49卷 841-849页

作者： OHSUMI, A Control and Systems Science Group Department of Mechanical and System Engineering Kyoto Institute of Technology Kyoto Matsugasaki Sakyo Japan

The quantum-mechanical formulation of a class of stochastic optimal control problems is investigated and two versions of non-linear Schrödinger equation are derived. First, a wave-function is introduced which connects the probability density function of a diffusion process with the minimum cost functional of the stochastic optimal control problem associated with the diffusion process. It is then demonstrated that this wave-function satisfies a kind of Schrödinger-Langevin equation in quantum physics. Finally, the probabilistic interpretation of the wave-function is discussed.

关键词： control systems, Optimal

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Heterogeneous multi-agent resource allocation through multi-bidding with applications to precision agriculture⁎

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IFAC-PapersOnLine 2018年第23期51卷 194-199页

作者： Cobbenhagen, A.T.J.R. Antunes, D.J. van de Molengraft, M.J.G. Heemels, W.P.M.H. Control Systems Technology group Dept. of Mechanical Engineering Eindhoven University of Technology Eindhoven Netherlands

In this paper we consider the problem of allocating multiple resources to a number of clients by a group of heterogeneous agents over time such that the clients can produce products while maximizing a profit function. We propose an approximate optimization framework in which every client provides multiple bids from which the agents choose such that an allocation is feasible and that the profit function is maximized over time. The proposed framework exploits decomposition techniques that can be used for large-scale multi-agent resource allocation problems in which the cost objective is additive, the dynamics of product generation is non-linear and the agents have different capabilities. Interestingly, the decomposition can be solved in a distributed fashion, enabling application to large-scale problems. We apply this decomposition to the management of resources and agents in precision agriculture as an inspirational and important application domain of the obtained results. We show that our framework can be used in order to schedule the time, location and quantity of resources that every agent must provide whilst optimizing the profit of the entire farm over the growing season. © 2018

关键词： Dynamic programming Agriculture Multi agent systems Precision agriculture Profitability Resource allocation Approximate dynamic programming Approximate optimization Decomposition technique Distributed optimization Heterogeneous agents Multi agent Optimal controls Resource allocation problem

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FREQUENCY-DOMAIN CURVE-FITTING WITH MAXIMUM AMPLITUDE CRITERION AND GUARANTEED STABILITY

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INTERNATIONAL JOURNAL OF control 1994年第5期60卷 809-825页

作者： HAKVOORT, RG VANDENHOF, PMJ [a]Mechanical Engineering Systems and Control Group Delft University of Technology Mekelweg 2 2628 CD Delft The Netherlands

The problem is considered of fitting a stable rational transfer function to complex frequency response data minimizing a weighted maximum amplitude criterion. A solution for this problem is provided in both discrete and continuous time and for both SISO and MIMO systems by parametrizing the transfer function and solving a smooth nonlinear constrained optimization problem. The denominator is parametrized as a product of first and second-order polynomials. By adding linear constraints on the denominator parameters to the nonlinear programming problem the poles of the curve fit model are restricted to the stability region in the complex plane. To provide an initial estimate for the nonlinear optimization problem an iterative procedure is proposed where, in each step, a linear programming problem has to be solved.

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LOADING OF SHOULDER GIRDLE MUSCLES IN CONSEQUENCE OF A GLENOHUMERAL ARTHRODESIS

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CLINICAL BIOMECHANICS 1994年第3期9卷 139-148页

作者： VANDERHELM, FCT PRONK, GM Man-Machine Systems Group Laboratory for Measurement and Control Department of Mechanical Engineering and Marine Technology Delft University of Technology Delft The Netherlands

Sometimes a glenohumeral arthrodesis operation is performed at patients with a brachial plexus lesion. In the glenohumeral arthrodesis the humerus is fused to the scapula. The fusion angles between scapula and humerus determine the restoration of function after the operation. In this study the effect of fusion angles on the hand position and maximal force exertion has been simulated using a musculoskeletal model of the shoulder girdle. Mean scapular and clavicular positions (10 subjects) are used as input variables. Mean fusion angles (18 patients with a glenohumeral arthrodesis) are used as reference position. Output variables are the maximal force which can be exerted with the hand and muscle forces of the thoracoscapular muscles. In order to achieve a mobility area in the mid-sagittal plane, the humerus should be internally rotated 60 degrees with a little abduction and forward flexion. Maximal force can be exerted when the scapula is laterally rotated and protracted beside the thorax. In that position m. serratus anterior has good moment arm to counterbalance the external moment. It is recommended to use an external fixator for the glenohumeral arthrodesis in order to be able to adjust the fusion angles outside the operation theatre.

关键词： GLENOHUMERAL ARTHRODESIS SHOULDER SHOULDER GIRDLE BIOMECHANICS MUSCULOSKELETAL MODEL

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Sparse Bayesian Identification of Polynomial NARX Models

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IFAC-PapersOnLine 2015年第28期48卷 172-177页

作者： Jacobs, William R. Baldacchino, Tara Anderson, Sean R. Department of Automatic Control and Systems Engineering University of Shefield Shefield United Kingdom Dynamics Research Group Department of Mechanical Engineering University of Shefield Dynamics Research Group Department of Mechanical Engineering University of Shefield Shefield United Kingdom

In this paper a novel sparse Bayesian structure detection algorithm is introduced for the identification of nonlinear autoregressive with exogenous inputs (NARX) dynamic systems. The main advantage of this algorithm over alternatives is that parameter uncertainty is naturally incorporated, and parameter estimation by variational inference is computationally efficient, consisting of a sequence of closed form updates. The proposed framework is demonstrated through a commonly used simulated benchmark problem. © 2015

关键词： Inference engines Identification (control systems) Automatic relevance determination Bench mark problems Computationally efficient NARX models Non linear autoregressive with exogenous Parameter uncertainty Variational bayes Variational inference

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Self-triggered and event-driven control for linear systems with stochastic delays

Self-triggered and event-driven control for linear systems w...

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2017 American control Conference, ACC 2017

作者： Prakash, S. Van Horssen, E.P. Antunes, D. Heemels, W.P.M.H. Control Systems Technology Group Department of Mechanical Engineering Eindhoven University of Technology Netherlands

ISBN: (纸本)9781509059928

Delays are often present in embedded and networked control loops and represent one of the main sources of performance limitations. In this paper, we propose two aperiodic control strategies to optimize closed-loop performance in the presence of stochastic delays: (i) a self-triggered strategy, in which the deadline to drop data is decided on-line based on the current state;(ii) an event-driven strategy, whereby the control input is updated immediately after the delayed data becomes available, leading in general to faster but time-varying control loops. These schemes are designed and analyzed using a standard LQG framework, which allows for assessing and comparing closed-loop performance. We establish that our self-triggered strategy always achieves a better closed-loop performance than periodic control with an optimal sampling period. Moreover, we provide examples where the event-driven strategy outperforms the self-triggered strategy and examples where the opposite is observed. © 2017 American Automatic control Council (AACC).

关键词： Linear systems

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Analysis of linear quadratic control loops with decentralized event-triggered sensing: Rate and performance guarantees 56

Analysis of linear quadratic control loops with decentralize...

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56th IEEE Annual Conference on Decision and control, CDC 2017

作者： Balaghi, I.M. Hadi Antunes, Duarte J. Control Systems Technology Group Department of Mechanical Engineering Eindhoven University of Technology Netherlands

ISBN: (纸本)9781509028733

We consider a control loop with several distributed sensor agents. Each sensor measures a subset of the states and broadcasts data to a remote controller and the other sensors according to a threshold-based event-triggered policy. This policy specifies that each sensor transmits data when the norm of the error between the actual measurement and an estimate of this measurement exceeds a threshold. The controller incorporates a state estimator relying on the data received from the sensors and enforces a linear feedback control policy. Considering an average quadratic performance index, we provide: (i) upper bounds on the performance of such a decentralized event-triggered policy with respect to the optimal policy when all the agents transmit at maximum rate;and (ii) lower bounds on the average inter-transmission time for the overall networked control system. Moreover, we discuss the conservativeness of the bounds considering some simple cases. The usefulness of the results is highlighted via a numerical example. © 2017 IEEE.

关键词： Networked control systems

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Suppression of high frequent resonances by applying tuned mass dampers 12

Suppression of high frequent resonances by applying tuned ma...

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12th International Conference of the European Society for Precision engineering and Nanotechnology, EUSPEN 2012

作者： Verbaan, C.A.M. Rosielle, P.C.J.N. Steinbuch, M. Control Systems Technology Group Department of Mechanical Engineering Eindhoven University of Technology Netherlands

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Reachability analysis for piecewise affine systems with neural network-based controllers 63

Reachability analysis for piecewise affine systems with neur...

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63rd IEEE Conference on Decision and control, CDC 2024

作者： Teichrib, Dieter Darup, Moritz Schulze Tu Dortmund University Control and Cyberphysical Systems Group Department of Mechanical Engineering Germany

ISBN: (纸本)9798350316339

Neural networks (NN) have been successfully applied to approximate various types of complex control laws, resulting in low-complexity NN -based controllers that are fast to evaluate. However, when approximating control laws using NN, performance and stability guarantees of the original controller may not be preserved. Recently, it has been shown that it is possible to provide such guarantees for linear systems with NNbased controllers by analyzing the approximation error with respect to a stabilizing base-line controller or by computing reachable sets of the closed-loop system. The latter has the advantage of not requiring a base-line controller. In this paper, we show that similar ideas can be used to analyze the closed-loop behavior of piecewise affine (PWA) systems with an NNbased controller. Our approach builds on computing overapproximations of reachable sets using mixed-integer linear programming, which allows to certify that the closed-loop system converges to a small set containing the origin while satisfying input and state constraints. We also show how to modify a given NN-based controller to ensure asymptotic stability for the controlled PWA system. © 2024 IEEE.

关键词： Mixed-integer linear programming

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