Stochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systems

This work proposes a new method for simultaneous probabilistic identification and control of an observable, fully-actuated mechanical system. Identification is achieved by conditioning stochastic process priors on observations of configurations and noisy estimates of configuration derivatives. In co...

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Main Authors: Calliess, J, Papachristodoulou, A, Roberts, S
Format: Journal article
Published: 2013
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author Calliess, J
Papachristodoulou, A
Roberts, S
author_facet Calliess, J
Papachristodoulou, A
Roberts, S
author_sort Calliess, J
collection OXFORD
description This work proposes a new method for simultaneous probabilistic identification and control of an observable, fully-actuated mechanical system. Identification is achieved by conditioning stochastic process priors on observations of configurations and noisy estimates of configuration derivatives. In contrast to previous work that has used stochastic processes for identification, we leverage the structural knowledge afforded by Lagrangian mechanics and learn the drift and control input matrix functions of the control-affine system separately. We utilise feedback-linearisation to reduce, in expectation, the uncertain nonlinear control problem to one that is easy to regulate in a desired manner. Thereby, our method combines the flexibility of nonparametric Bayesian learning with epistemological guarantees on the expected closed-loop trajectory. We illustrate our method in the context of torque-actuated pendula where the dynamics are learned with a combination of normal and log-normal processes.
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spelling oxford-uuid:be38e015-8c8d-49f5-9af8-d321fe7df42d2022-03-27T05:37:36ZStochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systemsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:be38e015-8c8d-49f5-9af8-d321fe7df42dSymplectic Elements at Oxford2013Calliess, JPapachristodoulou, ARoberts, SThis work proposes a new method for simultaneous probabilistic identification and control of an observable, fully-actuated mechanical system. Identification is achieved by conditioning stochastic process priors on observations of configurations and noisy estimates of configuration derivatives. In contrast to previous work that has used stochastic processes for identification, we leverage the structural knowledge afforded by Lagrangian mechanics and learn the drift and control input matrix functions of the control-affine system separately. We utilise feedback-linearisation to reduce, in expectation, the uncertain nonlinear control problem to one that is easy to regulate in a desired manner. Thereby, our method combines the flexibility of nonparametric Bayesian learning with epistemological guarantees on the expected closed-loop trajectory. We illustrate our method in the context of torque-actuated pendula where the dynamics are learned with a combination of normal and log-normal processes.
spellingShingle Calliess, J
Papachristodoulou, A
Roberts, S
Stochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systems
title Stochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systems
title_full Stochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systems
title_fullStr Stochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systems
title_full_unstemmed Stochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systems
title_short Stochastic processes and feedback-linearisation for online identification and Bayesian adaptive control of fully-actuated mechanical systems
title_sort stochastic processes and feedback linearisation for online identification and bayesian adaptive control of fully actuated mechanical systems
work_keys_str_mv AT calliessj stochasticprocessesandfeedbacklinearisationforonlineidentificationandbayesianadaptivecontroloffullyactuatedmechanicalsystems
AT papachristodouloua stochasticprocessesandfeedbacklinearisationforonlineidentificationandbayesianadaptivecontroloffullyactuatedmechanicalsystems
AT robertss stochasticprocessesandfeedbacklinearisationforonlineidentificationandbayesianadaptivecontroloffullyactuatedmechanicalsystems