Predictor-Based Motion Tracking Control for Cloud Robotic Systems with Delayed Measurements

Shen, Shaobo; Song, Aiguo; Li, Tao

doi:10.3390/electronics8040398

Cited by 9 publications

(7 citation statements)

References 40 publications

(54 reference statements)

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“…Similarly to the FCS module, approaches ranging from the more traditional techniques up to more innovative techniques based on artificial intelligence have been used in the CPD-HSD and JPD-HSD modules [39]- [43]. Thus, it can be said that θ HSD (n) is an estimate of the b(n) signal generated by the MD.…”

Section: Simulated Tactile Internet Modelmentioning

confidence: 99%

Reconfigurable Computing Applied to Latency Reduction for the Tactile Internet

Junior,

Torquato,

Mahmoodi

et al. 2020

Preprint

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Tactile internet applications allow robotic devices to be remotely controlled over a communication medium with an unnoticeable time delay. In a bilateral communication, the acceptable round trip latency is usually in the order of 1 ms up to 10 ms depending on the application requirements. It is estimated that 70% of the total latency is generated by the communication network, and the remaining 30% is produced by master and slave devices. Thus, this paper aims to propose a strategy to reduce the 30% of total latency that is produced by such devices. The strategy is to apply reconfigurable computation using FPGAs to minimize the execution time of device-associated algorithms. With this in mind, this work presents a hardware reference model for modules that implement nonlinear positioning and force calculations as well as a tactile system formed by two robotic manipulators. In addition to presenting the implementation details, simulations and experimental tests are performed in order to validate the proposed model. Results associated with the FPGA sampling rate, throughput, latency and post-synthesis occupancy area are analyzed.

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Section: Simulated Tactile Internet Modelmentioning

confidence: 99%

Reconfigurable Computing Applied to Latency Reduction for the Tactile Internet

Junior,

Torquato,

Mahmoodi

et al. 2020

Preprint

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“…In the case of systems with no time delay in the response, SMC proved to be an effective control strategy [10,25]; however, when there is a delay in the response, the control does not perform adequately. As seen in the introduction, there are several strategies to improve control in time-delay systems [29][30][31][32][33][34].…”

Section: Smc With Dynamical Correctionmentioning

confidence: 99%

“…Under those conditions, the strategies aim to adequately adjust the control signal, taking into account the system's behavior, to achieve an effective and stable response. Researchers have been successful in using predictors that model the system performance, such as smith predictors to adequately adjust the input control and achieve a better performance [30,31]. If the system is subjected to a periodic signal reference, a sliding mode control with repetitive control can optimize the system performance, but the control must be robust enough to avoid aperiodic disturbances [32].…”

Section: Introductionmentioning

confidence: 99%

Sliding Mode Control with Dynamical Correction for Time-Delay Piezoelectric Actuator Systems

et al. 2019

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In piezoelectric actuators (PEAs), which suffer from inherent nonlinearities, sliding mode control (SMC) has proven to be a successful control strategy. Nonetheless, in micropositioning systems with time delay, integral proportional control (PI), and SMC, feedback control schemes have a tendency to overcompensate and, consequently, high controller gains must be rejected. This may produce a slow and inaccurate response. This paper presents a novel control strategy that deals with time-delay micropositioning systems aimed at achieving precise positioning by combining an open-loop control with a modified SMC scheme. The proposed SMC with dynamical correction (SMC-WDC) uses the dynamical system model to adapt the SMC inputs and avoid undesirable control response caused by delays. In order to develop the SMC-WDC scheme, an exhaustive analysis on the micropositioning system was first performed. Then, a mixed control strategy, combining inverse open-loop control and SMC-WDC, was developed. The performance of the presented control scheme was analyzed and compared experimentally with other control strategies (i.e., PI and SMC with saturation and hyperbolic functions) using different reference signals. It was found that the SMC-WDC strategy presents the best performance, that is, the fastest response and highest accuracy, especially against sudden changes of reference setpoints (frequencies >10 Hz). Additionally, if the setpoint reference frequencies are higher than 10 Hz, high integral gains are counterproductive (since the control response increases the delay), although if frequencies are below 1 Hz the integral control delay does not affect the system’s accuracy. The SMC-WDC proved to be an effective strategy for micropositioning systems, dealing with time delay and other uncertainties to achieve the setpoint command fast and precisely without chattering.

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“…As for networked control systems, some significant issues are addressed: the impact of delays on network-based systems for droop-controlled AC microgrid is investigated in Reference [8]; Tracking control for cloud robotic systems with delayed measurements is considered in Reference [9]; An event-triggered fault detection approach to cyber-physical systems with sensor nonlinearities and deception attacks is presented in Reference [10]; and a non-standard discretization method is introduced to stability analysis of sampled-data systems in Reference [11].…”

Section: The Special Issuementioning

confidence: 99%