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In recent years, owing to the rapidly increasing labor costs, the demand for robots in daily services and industrial operations has been increased significantly. For further applications and human–robot interaction in an unstructured open environment, fast and accurate tracking and strong disturbance rejection ability are required. However, utilizing a conventional controller can make it difficult for the robot to meet these demands, and when a robot is required to perform at a high-speed and large range of motion, conventional controllers may not perform effectively or even lead to the instability.

The main idea is to develop the control law by combining the SMC feedback with the ADRC control architecture to improve the robustness and control quality of a conventional SMC controller. The problem is formulated and solved in the framework of ADRC. For better estimation and control performance, a generalized proportional integral observer (GPIO) technique is employed to estimate and compensate for unmodeled dynamics and other unknown time-varying disturbances. And benefiting from the usage of GPIO, a new SMC law can be designed by synthesizing the estimation and its history.

The employed methodology introduced a significant improvement in handling the uncertainties of the system parameters without compromising the nominal system control quality and intuitiveness of the conventional ADRC design. First, the proposed method combines the advantages of the ADRC and SMC method, which achieved the best tracking performance among these controllers. Second, the proposed controller is sufficiently robust to various disturbances and results in smaller tracking errors. Third, the proposed control method is insensitive to control parameters which indicates a good application potential.

High-performance robot tracking control is the basis for further robot applications in open environments and human–robot interfaces, which require high tracking accuracy and strong disturbance rejection. However, both the varied dynamics of the system and rapidly changing nonlinear coupling characteristic significantly increase the control difficulty. The proposed method gives a new replacement of PID controller in robot systems, which does not require an accurate dynamic system model, is insensitive to control parameters and can perform promisingly for response rapidity and steady-state accuracy, as well as in the presence of strong unknown disturbances.

Steer-by-wire (SBW) system mainly relies on sensors, controllers and motors to replace the traditionally mechanical transmission mechanism to realize steering functions. However, the sensors in the SBW system are particularly vulnerable to external influences, which can cause systemic faults, leading to poor steering performance and even system instability. Therefore, this paper aims to adopt a fault-tolerant control method to solve the safety problem of the SBW system caused by sensors failure.

This paper proposes an active fault-tolerant control framework to deal with sensors failure in the SBW system by hierarchically introducing fault observer, fault estimator, fault reconstructor. Firstly, the fault observer is used to obtain the observation output of the SBW system and then obtain the residual between the observation output and the SBW system output. And then judge whether the SBW system fails according to the residual. Secondly, dependent on the residual obtained by the fault observer, a fault estimator is designed using bounded real lemma and regional pole configuration to estimate the amplitude and time-varying characteristics of the faulty sensor. Eventually, a fault reconstructor is designed based on the estimation value of sensors fault obtained by the fault estimator and SBW system output to tolerate the faulty sensor.

The numerical analysis shows that the fault observer can be rapidly activated to detect the fault while the sensors fault occurs. Moreover, the estimation accuracy of the fault estimator can reach to 98%, and the fault reconstructor can make the faulty SBW system to retain the steering characteristics, comparing to those of the fault-free SBW system. In addition, it was verified for the feasibility and effectiveness of the proposed control framework.

As the SBW fault diagnosis and fault-tolerant control in this paper only carry out numerical simulation research on sensors faults in matrix and laboratory/Simulink, the subsequent hardware in the loop test is needed for further verification.

Aiming at the SBW system with parameter perturbation and sensors failure, this paper proposes an active fault-tolerant control framework, which integrates fault observer, fault estimator and fault reconstructor so that the steering performance of SBW system with sensors faults is basically consistent with that of the fault-free SBW system.

The flexibility of batch process enables its wide application in fine-chemical, pharmaceutical and semi-conductor industries, whilst its complexity necessitates control performance monitoring to ensure high operation efficiency. This paper proposes a data-driven approach to carry out controller performance monitoring within batch based on linear quadratic Gaussian (LQG) method.

A linear time-varying LQG method is proposed to obtain the joint covariance benchmark for the stochastic part of batch process input/output. From historical golden operation batch, linear time-varying (LTV) system and noise models are identified based on generalized observer Markov parameters realization.

Open/closed loop input and output data are applied to identify the process model as well as the disturbance model, both in Markov parameter form. Then the optimal covariance of joint input and output can be obtained by the LQG method. The Hotelling's Tˆ2 control chart can be established to monitor the controller.

(1) An observer Markov parameter approach to identify the time-varying process and noise models from both open and closed loop data, (2) a linear time-varying LQG optimal control law to obtain the optimal benchmark covariance of joint input and output and (3) a joint input and output multivariate control chart based on Hotelling's T² statistic for controller performance monitoring.

As the strategy of 5G new infrastructure is deployed and advanced, 5G-R becomes the primary technical system for future mobile communication of China’s railway. V2V communication is also an important application scenario of 5G communication systems on high-speed railways, so time synchronization between vehicles is critical for train control systems to be real-time and safe. How to improve the time synchronization performance in V2V communication is crucial to ensure the operational safety and efficiency of high-speed railways.

This paper proposed a time synchronization method based on model predictive control (MPC) for V2V communication. Firstly, a synchronous clock for V2V communication was modeled based on the fifth generation mobile communication-railway (5G-R) system. Secondly, an observation equation was introduced according to the phase and frequency offsets between synchronous clocks of two adjacent vehicles to construct an MPC-based space model of clock states of the adjacent vehicles. Finally, the optimal clock offset was solved through multistep prediction, rolling optimization and other control methods, and time synchronization in different V2V communication scenarios based on the 5G-R system was realized through negative feedback correction.

The results of simulation tests conducted with and without a repeater, respectively, show that the proposed method can realize time synchronization of V2V communication in both scenarios. Compared with other methods, the proposed method has faster convergence speed and higher synchronization precision regardless of whether there is a repeater or not.

This paper proposed an MPC-based time synchronization method for V2V communication under 5G-R. Through the construction of MPC controllers for clocks of adjacent vehicles, time synchronization was realized for V2V communication under 5G-R by using control means such as multistep prediction, rolling optimization, and feedback correction. In view of the problems of low synchronization precision and slow convergence speed caused by packet loss with existing synchronization methods, the observer equation was introduced to estimate the clock state of the adjacent vehicles in case of packet loss, which reduces the impact of clock error caused by packet loss in the synchronization process and improves the synchronization precision of V2V communication. The research results provide some theoretical references for V2V synchronous wireless communication under 5G-R technology.

Teachers of primary education experience high levels of stress but lack rational coping strategies to reduce their work stress. The paper develops a value stream mapping for education approach and examines its use as a rational coping strategy for teams of teachers and other employees to overcome work-related stressors.

The research process consists of two phases. First, a value stream mapping approach for education is developed, based on literature research. Next, the approach is validated in an action research study to reduce work stress of teachers in educational services. The processes that have been selected by the teachers relate to coping with increased variety, long and uncertain throughput times and unclear specifications.

Value stream mapping for education (VSM4EDU) is a well-structured improvement method based on principles of visualization, participation and process thinking, which helps teachers without background in lean thinking to analyse their processes. Using this method has enabled the team to develop rational coping strategies to reduce their work-related stress.

VSM4EDU has been validated using action research at a single school, which implicates deep insight, but further testing at other schools is welcome. Moreover, VSM4EDU has not been used to develop a future state map.

Value stream mapping is useful in educational settings as long as the educational context is respected in the approach.

VSM4EDU empowers teachers and helps to develop co-operation in teams.

The validation of value stream mapping for education is well-documented and original.

The study explores the alignment of Swiss small and medium-sized enterprise (SME) managers' understanding of digital transformation, with evidence of digital tool adoption in managerial and operative work. This reveals opportunities for more fully realizing the potential of digital transformation for SMEs.

This multiple-case study, with four theoretically sampled cases, analyzes data from the qualitative answers of 1,593 respondents to a survey of Swiss SMEs about digital transformation. The study draws on a convenience sample of Swiss SME managers.

The analysis shows little understanding of digital transformation as related to managerial work. However, there are two clear digital tool adoption patterns for managerial work: (1) workflow and workforce management and (2) work-flow and team management. Understandings of digital transformation and operative work focus on the (1) organization of operational work or (2) a combination of organization and changing the way people work. The digital tool adoption in operational work additionally focuses on the digital skills of operational employees.

The study is only able to identify patters of understanding of digital transformation and digital tool adoption in managerial and operative work. More research is needed to understand why these patterns are observed.

SME managers need to think far more carefully about aligning their vision for digital transformation and the digital tools they adopt in both managerial and operational work, but especially in managerial work.

This is the first empirical study of the digital transformation of Swiss SMEs and their digital tool adoption. Significant potential for alignment is revealed, suggesting potential performance gains are possible.

Twenty-first century crises reaffirm the need of faster mobilization of resources during crises. Without interorganizational collaboration and resource mobilization, organizing efficient response is not possible. Resource mobilization is an essential aspect of response. It ensures a faster and better response. Collaboration between teams of emergency responders may include commonly known boundary spanning activities such as resource sharing, information sharing and communication. The purpose of this paper is to contribute our knowledge of how to organize a better crisis response through collaboration. More precisely, what strategies work as drivers for emergency responder teams during collaboration in crisis scenarios.

Through design of experiments, using tabletop exercises and online surveys, this study investigates the drivers of collaboration during a crisis scenario. Participants of this study are decision makers and emergency responders from various public actors in crisis management from Sweden.

Collaboration is essential to manage cross-functional services in normal times, as well as meet the growing needs during crises. In absence of collaboration, boundary spanning activities such as sharing resources or information to provide any kind of service will not be possible. For teams to survive in fast-changing environment, they must be able to adapt to the changing demands accordingly. This paper demonstrates which factors are drivers for emergency responders to mobilize resources, especially during crises. It captures the tension between individual and collective goals in crisis response and highlights the drivers that affect decision-making during crises.

The novelty of the paper lies in its methodology using tabletop exercises, design of experiments as part of Six Sigma toolbox and online surveys in combination with weightage of agreements and disagreements and free text answers. Although scientific research so far has demonstrated the need for collaboration during crises, however, which factors act as drivers for emergency responders to collaborate, is lacking scientific evidence. Incentives for collaboration have not been studied enough. These can tell us which strategies can improve collaboration during crises. This research paper is a scientific contribution in that direction.