Delay Compensation for Real Time Disturbance Estimation at Extremely Large Telescopes

Böhm, Michael; Pott, Jörg-Uwe; Kürster, M.; Sawodny, Oliver; Defrère, Denis; Hinz, Philip M.

doi:10.1109/tcst.2016.2601627

Cited by 26 publications

(25 citation statements)

References 24 publications

(41 reference statements)

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“…where ǫ 0 ∈ R + , the boundary scalars m o , c O , d O and h O are respectively defined in (10), (11), (15) and (21), and I n is the n-dimensional identity matrix, then e 1 (t) and e 2 (t) converge to the zero equilibria as in (22a) and (22b) respectively in finite time t 1 and t 2 , where t 1 , t 2 < +∞ are bounded by…”

Section: Stability Analysismentioning

confidence: 99%

“…For example, in human-robot interaction (HRI), it is important to detect and classify collisions and contacts to guarantee safety in collaborative tasks [10], [11], such that robots and humans are allowed to share the same workspace and physical injuries are avoided [12]- [14]. More generally, disturbance estimation is also popularly studied for feed-forward disturbance compensation control [8], [15], robust control [16], [17] or fault-tolerant control [18], [19] strategies for various mechatronic systems.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Integral Sliding-Mode Observer-Based Disturbance Estimation for Euler–Lagrangian Systems

Zhang

Leibold

Wollherr

2020

IEEE Trans. Contr. Syst. Technol.

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In this paper, a novel integral sliding mode observer is proposed to estimate the external disturbance and velocity of Euler-Lagrangian systems. This method provides high bandwidth and precise estimation with only commanded input and position measurement. A system velocity measurement is not required to construct the sliding mode manifold. The convergence of the estimation error to zero is theoretically in finite time, which is proved by a direct Lyapunov method utilizing the passivity property of Euler-Lagrangian systems. An integral sliding manifold is designed to reduce the reaching phase, such that the robustness of the estimation is enhanced. The method has been applied to a robot manipulator to estimate the joint velocity and external contact forces in a physical human-robot task. Simulations and experiments reveal that this novel method provides fast, precise and robust estimation results and can be used to replace the measurement of an external force sensor. The successful application of this observer to a force-sensorless admittance controller for a manipulator contributes to the implementation of a sensor-free safety framework for humanrobot collaboration.

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Section: Stability Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Integral Sliding-Mode Observer-Based Disturbance Estimation for Euler–Lagrangian Systems

Zhang

Leibold

Wollherr

2020

IEEE Trans. Contr. Syst. Technol.

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“…according to Reference [30]. The nominal plant of acceleration open-loop object, which is acquired by identifying the result of the DSA, is depicted in Equation (19). The controller of the acceleration feedback control loop is designed as Equation (20).…”

Section: Experimental Verificationmentioning

confidence: 99%

“…To improve the performance of the TCS, the feedforward method based on direct measurement is also introduced as it can suppress most of the theoretical external disturbances [19,20]. However, it involves additional cost for another sensor and specific environments with low measurable noise.…”

Section: Introductionmentioning

confidence: 99%

A Modified Disturbance Observer Structure Based on Acceleration Measurement for Disturbance Suppression in Tracking Control System

et al. 2018

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The micro-electro-mechanical system (MEMS) accelerometer is widely adopted in many engineering control systems due to its extraordinary performance with high bandwidth, small size and low weight. However, massive drift caused by its insensitively at low frequency is the main factor which limits its performance. It leads to integral saturation when the feedforward method is used and hinders the improvement of disturbance suppression ability at low frequency, which is a significant factor for evaluating the closed-loop performance of a high-precision tracking system. To solve this problem, a modified disturbance observer structure and its corresponding new controller, which can improve disturbance suppression performance at low frequency by effectively rejecting more drift and weakening the occurrence possibility of integral saturation when drift exists, are proposed. Detailed analyses and a series of comparative experimental results verify that the proposed method can effectively enhance disturbance suppression performance at low frequency.

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“…However, an additional position sensor was required, which was only suitable for the condition with low measurement noise. Similarly, in order to detect the disturbances, additional sensors should be equipped on the pedestal [19,20]; the wind disturbance and cogging force cannot be reflected from the pedestal. Hence, the feedforward control based on direct measurement could not be easily implemented, especially for the space and cost limited occasions.…”

Section: Introductionmentioning

confidence: 99%

Feedforward Control Based on Error and Disturbance Observation for the CCD and Fiber-Optic Gyroscope-Based Mobile Optoelectronic Tracking System

et al. 2018

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In the mobile optoelectronic tracking system (MOTS) based on charge-coupled device (CCD) and fiber-optic gyroscope (FOG), the tracking performance (TP) and anti-disturbance ability (ADA) characterized by boresight error are of equal importance. Generally, the position tracking loop, limited by the image integration time of CCD, would be subject to a non-negligible delay and low-sampling rate, which could not minimize the boresight error. Although the FOG-based velocity loop could enhance the ADA of the system, it is still insufficient in the case of some uncertain disturbances. In this paper, a feedforward control method based on the results of error and disturbance observation was proposed. The error observer (EOB) based on the CCD data and model output essentially combined the low-frequency tracking feedforward and closed-loop disturbance observer (DOB), which could simultaneously enhance the low-frequency TP and ADA. In addition, in view of the poor low-frequency performance of the FOG due to drift and noise that may result in the inaccuracy of the observed low-frequency disturbance, the FOG-based DOB was used to improve the relatively high-frequency ADA. The proposed method could make EOB and DOB complementary and help to obtain a high-precision MOTS, for in practical engineering, we give more attention to the low-frequency TP and full-band ADA. Simulations and experiments demonstrated that the proposed method was valid and had a much better performance than the traditional velocity and position double-loop control (VPDC).

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Delay Compensation for Real Time Disturbance Estimation at Extremely Large Telescopes

Cited by 26 publications

References 24 publications

Integral Sliding-Mode Observer-Based Disturbance Estimation for Euler–Lagrangian Systems

Integral Sliding-Mode Observer-Based Disturbance Estimation for Euler–Lagrangian Systems

A Modified Disturbance Observer Structure Based on Acceleration Measurement for Disturbance Suppression in Tracking Control System

Feedforward Control Based on Error and Disturbance Observation for the CCD and Fiber-Optic Gyroscope-Based Mobile Optoelectronic Tracking System

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