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Encoding Physical Constraints in Differentiable Newton-Euler Algorithm [article]

Giovanni Sutanto, Austin S. Wang, Yixin Lin, Mustafa Mukadam, Gaurav S. Sukhatme, Akshara Rai, Franziska Meier
2020 arXiv   pre-print
The recursive Newton-Euler Algorithm (RNEA) is a popular technique for computing the dynamics of robots.  ...  However, the dynamics parameters learned in this manner can be physically implausible. In this work, we incorporate physical constraints in the learning by adding structure to the learned parameters.  ...  differentiable recursive Newton-Euler algorithm.  ... 
arXiv:2001.08861v4 fatcat:wsqwoq6tyvhffpfret3fg4ad3m

Interactive Differentiable Simulation [article]

Eric Heiden, David Millard, Hejia Zhang, Gaurav S. Sukhatme
2020 arXiv   pre-print
We introduce Interactive Differentiable Simulation (IDS), a differentiable physics engine, that allows for efficient, accurate inference of physical properties of rigid-body systems.  ...  Intelligent agents need a physical understanding of the world to predict the impact of their actions in the future.  ...  Algorithm 1 Adaptive MPC algorithm using differentiable physics.  ... 
arXiv:1905.10706v3 fatcat:3d7572kkb5fljj3mddovpe4zvu

Interactive Physically-Based Simulation of Roadheader Robot [article]

Shengzhe Hou, Xinming Lu, Wenli Gao, Shuai Jiang, Xingli Zhang
2022 arXiv   pre-print
Second, we adopt the symplectic Euler integrator instead of the conventional fourth-order Runge-Kutta (RK4) method for dynamics iteration.  ...  There are few studies that apply real-time physical simulation of computer graphics to the field of roadheader robot.  ...  This work was supported in part by the National Key Research and Development Projects of China under Grant 2017YFC0804406, and in part by the National Natural Science Foundation of China under Grant 51904173  ... 
arXiv:2206.15429v1 fatcat:housx7x6kzcxtc7ecd36fsgpbm

Identification of Robot Dynamics from Motor Currents/Torques with Unknown Signs

Marco Pennese, Claudio Gaz, Marco Capotondi, Valerio Modugno, Alessandro De Luca
2021 Zenodo  
The method consists in solving a sequence of constrained optimization problems, exploiting physical feasibility constraints.  ...  ., in the KUKA KR5 Sixx) return the user only the absolute values of the motor currents (or of the torques), thus preventing a correct dynamic estimation.  ...  using the recursive numerical Newton-Euler algorithm to implement torque-level control laws (such as feedback linearization) under hard realtime constraints.  ... 
doi:10.5281/zenodo.6367963 fatcat:xrec6tipvjgtlmrkjsrsojq5ee

A Sequential Homotopy Method for Mathematical Programming Problems [article]

Andreas Potschka, Hans Georg Bock
2019 arXiv   pre-print
We propose a sequential homotopy method for the solution of mathematical programming problems formulated in abstract Hilbert spaces under the Guignard constraint qualification.  ...  small, and can be solved by a continuation in the stepsize.  ...  [3, 1] in combination with Algorithmic Differentiation [24] , as it is implemented in the DOLFIN/FEniCS project [39, 40, 2, 38] .  ... 
arXiv:1902.06984v3 fatcat:gyjg53x6kbclffjpafzhw4drme

Discrete optimal control on lie groups and applications to robotic vehicles

Marin Kobilarov
2014 2014 IEEE International Conference on Robotics and Automation (ICRA)  
The focus is on discrete optimal control methods which operate intrinsically in the state space system manifold and do not require coordinate charts or projections.  ...  This is accomplished by defining both the dynamics and the optimal control solution as sequences of vector fields mapping to curves on the Lie group through retraction maps, and defining variations and differentiation  ...  The inequality constraint encode control bounds.  ... 
doi:10.1109/icra.2014.6907671 dblp:conf/icra/Kobilarov14 fatcat:wcov7dvai5hnjmrz2q2limbxqu

Interactive Simulation of Rigid Body Dynamics in Computer Graphics [article]

Jan Bender, Kenny Erleben, Jeff Trinkle, Erwin Coumans
2012 Eurographics State of the Art Reports  
This paper is a self contained state-of-the-art report on the physics, the models, the numerical methods and the algorithms used in interactive rigid body simulation all of which has evolved and matured  ...  In perspective several avenues for possible future work is touched upon such as more descriptive models and contact point generation problems.  ...  In rigid body simulation, one begins with the Newton-Euler (differential) equations, which describes the dynamic motion of the bodies without contact.  ... 
doi:10.2312/conf/eg2012/stars/095-134 fatcat:rv6lggg4xna3tgz3tquy7wt2bm

DiffSDFSim: Differentiable Rigid-Body Dynamics With Implicit Shapes [article]

Michael Strecke, Joerg Stueckler
2021 arXiv   pre-print
Differentiable physics is a powerful tool in computer vision and robotics for scene understanding and reasoning about interactions.  ...  In this paper, we propose a novel approach to differentiable physics with frictional contacts which represents object shapes implicitly using signed distance fields (SDFs).  ...  Constraint-based time stepping dynamics Constraint-based time stepping methods formulate the dynamics as solving the Newton-Euler equations and add equality and inequality constraints to model joints,  ... 
arXiv:2111.15318v1 fatcat:joodra37ardw3ghpnbhrwkpnbi

Whole-Body Nonlinear Model Predictive Control Through Contacts for Quadrupeds

Michael Neunert, Markus Stauble, Markus Giftthaler, Carmine D. Bellicoso, Jan Carius, Christian Gehring, Marco Hutter, Jonas Buchli
2018 IEEE Robotics and Automation Letters  
In this work we present a whole-body Nonlinear Model Predictive Control approach for Rigid Body Systems subject to contacts.  ...  Hardware experiments in form of periodic and non-periodic tasks are applied to two quadrupeds with different actuation systems.  ...  Therefore, instead of using standard explicit integrators such as Euler or Runge-Kutta schemes, we use symplectic (or semi-implicit) integrators, which are also popular in physics engines [31] .  ... 
doi:10.1109/lra.2018.2800124 fatcat:7yfgd25tivcv3nysquhq3zrjze

Page 6847 of Mathematical Reviews Vol. , Issue 90M [page]

1990 Mathematical Reviews  
Shabana, Application of generalized Newton-Euler equations and recursive projection methods to dynamics of deformable multibody systems  ...  Proceedings of the Workshops on Solitons in Physics and Mathematics and Solitons in Nonlinear Optics and Plasma Physics held in Minneapolis, Minnesota, 1988-89. Edited by Peter J. Olver and David H.  ... 

Real-time model predictive control for keeping a quadrotor visible on the camera field-of-view of a ground robot

Wei Ding, Madan Ravi Ganesh, Robert N. Severinghaus, Jason J. Corso, Dimitra Panagou
2016 2016 American Control Conference (ACC)  
We design a model predictive controller (MPC) strategy where the visibility constraints of the camera and the control input constraints of the quadrotor are encoded into the cost function via barrier functions  ...  The applicability of the proposed algorithm is demonstrated through simulations and experimental results on real setups.  ...  an initial guess that satisfies inequality constraints, but does not need to meet the equality constraints. 2 Infeasible Start Newton Method: The infeasible start newton method is introduced in [30  ... 
doi:10.1109/acc.2016.7525254 dblp:conf/amcc/DingGSCP16 fatcat:6h75gs54hjbe5ne4bzunuqe62y

Modular Dynamic Simulation of Wheeled Mobile Robots [chapter]

Neal Seegmiller, Alonzo Kelly
2015 Springer Tracts in Advanced Robotics  
Simulation accuracy is verified in a physical experiment.  ...  Instead of directly adding contact forces, we solve for them in a novel differential algebraic equation (DAE) formulation. To make this possible we resolve issues of nonlinearity and overconstraint.  ...  We use the Recursive Newton-Euler Algorithm (RNEA) to compute the joint space bias force c, which includes the Coriolis and centripetal force terms, as shown in Algorithm 1.  ... 
doi:10.1007/978-3-319-07488-7_6 fatcat:arw7f2tx5je6lfhqfv536cqcum

Solvability of Geometric Integrators for Multi-body Systems [chapter]

Marin Kobilarov
2014 Computational Methods in Applied Sciences  
In addition to developing solvability conditions for systems described by local coordinates, this work initiates a similar discussion for Lie group integrators which are a favored choice for floating-base  ...  A convergent Newton algorithm will then perform iterations in the vicinity of the starting value v v k in the sense that all iterates v will be contained in the set B0 Bpv k d0, }d0}q, i.e. the ball at  ...  Such numerical algorithms are typically constructed by directly discretizing the differential equations that describe the trajectory of the system, resulting in an update rule to compute the next state  ... 
doi:10.1007/978-3-319-07260-9_7 fatcat:me7sitlh4jhwhg73ytniz5pfbm

Generative Graphical Models for Maneuvering Object Tracking and Dynamics Analysis

Xin Fan, Guoliang Fan
2007 2007 IEEE Conference on Computer Vision and Pattern Recognition  
This model also accommodates the physical constraints between maneuvering dynamics and object kinematics in a probabilistic form, allowing more accurate and efficient object tracking.  ...  in a graphical model.  ...  We direct an arc from v t to f t as shown in red in Fig. 2 to encode such constraint, so that object kinematics, say velocity, brings the influence to the forces.  ... 
doi:10.1109/cvpr.2007.383451 dblp:conf/cvpr/FanF07 fatcat:s2apbdpnhrf2vam64dw73vgzmu

Optimization Integrator for Large Time Steps

Theodore F. Gast, Craig Schroeder, Alexey Stomakhin, Chenfanfu Jiang, Joseph M. Teran
2015 IEEE Transactions on Visualization and Computer Graphics  
We show that recasting backward Euler as a minimization problem allows Newton's method to be stabilized by standard optimization techniques with some novel improvements of our own.  ...  Practical time steps in today's state-of-the-art simulators typically rely on Newton's method to solve large systems of nonlinear equations.  ...  As in the constraint case, we apply friction after the Newton solve.  ... 
doi:10.1109/tvcg.2015.2459687 pmid:26357249 fatcat:ztaqyrhucfcpfkxfdcrsk4eisu
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