Probabilistic Robustness Analysis of an Actively Controlled Structure that Operates in Harsh and Uncertain Environments

2018 ◽  
pp. 121-131
Author(s):  
Christopher J. D’Angelo ◽  
Daniel G. Cole ◽  
John C. Collinger
Keyword(s):  
Robustness Analysis ◽  
Uncertain Environments ◽  
Controlled Structure ◽  
Probabilistic Robustness

Novel fractional hybrid impedance control of series elastic muscle-tendon actuator

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Javad Fotuhi ◽  
Zafer Bingul
Keyword(s):  
Contact Stress ◽  
Impedance Control ◽  
Robustness Analysis ◽  
Simulation Models ◽  
Experimental Results ◽  
Uncertain Environments ◽  
Content Type ◽  
Force Tracking ◽  
Comparative Results ◽  
Series Elastic

Purpose This paper aims to develope a novel fractional hybrid impedance control (FHIC) approach for high-sensitive contact stress force tracking control of the series elastic muscle-tendon actuator (SEM-TA) in uncertain environments. Design/methodology/approach In three different cases, the fractional parameters of the FHIC were optimized with the particle swarm optimization algorithm. Its adaptability to the pressure of the sole of the foot on real environments such as grass (soft), carpet (medium) and solid floors (hard) is far superior to traditional impedance control. The main aim of this paper is to derive the dynamic simulation models of the SEM-TA, to develop a control architecture allowing for high-sensitive contact stress force control in three cases and to verify the simulation models and the proposed controller with experimental results. The performance of the optimized controllers was evaluated according to these parameters, namely, maximum overshoot, steady-state error, settling time and root mean squared errors of the positions. Moreover, the frequency robustness analysis of the controllers was made in three cases. Findings Different simulations and experimental results were conducted to verify the control performance of the controllers. According to the comparative results of the performance, the responses of the proposed controller in simulation and experimental works are very similar. Originality/value Origin approach and origin experiment.

New Algorithm for Probabilistic Robustness Analysis in Parameter Space

2009 ◽  
Vol 6 (4) ◽  
pp. 291-306 ◽  
Author(s):  
Gianfranco Morani ◽  
Federico Corraro ◽  
Antonio Vitale
Keyword(s):  
Parameter Space ◽  
Robustness Analysis ◽  
Probabilistic Robustness

scholarly journals Robustness Analysis of Floating-Point Programs by Self-Composition

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Liqian Chen ◽  
Jiahong Jiang ◽  
Banghu Yin ◽  
Wei Dong ◽  
Ji Wang
Keyword(s):  
Symbolic Execution ◽  
Robustness Analysis ◽  
Floating Point ◽  
Maximum Output ◽  
Critical Systems ◽  
Uncertain Environments ◽  
Software Model ◽  
Output Change ◽  
Interval Linear ◽  
Interval Coefficients

Robustness is a key property for critical systems that run in uncertain environments, to ensure that small input perturbations can cause only small output changes. Current critical systems often involve lots of floating-point computations which are inexact. Robustness analysis of floating-point programs needs to consider both the uncertain inputs and the inexact computation. In this paper, we propose to leverage the idea of self-composition to transform the robustness analysis problem into a reachability problem, which enables the use of standard reachability analysis techniques such as software model checking and symbolic execution for robustness analysis. To handle floating-point arithmetic, we employ an abstraction that encompasses the effect of rounding and that can encompass all rounding modes. It converts floating-point expressions into linear expressions with interval coefficients in exact real arithmetic. On this basis, we employ interval linear programming to compute the maximum output change or maximum allowed input perturbation for the abstracted programs. Preliminary experimental results of our prototype implementation are encouraging.

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