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Obstacle and wind field are common environmental factors for mini unmanned helicopter (MUH) flight. This paper aims to develop a trajectory planning approach guiding MUH to avoid static and dynamic obstacles and to fly in steady uniform or boundary-layer wind field.

An optimal control model including a nonlinear flight dynamics model and a cubic obstacle model is established for MUH trajectory planning. Radau pseudospectral method is used to generate the optimal trajectory.

The approach can plan reasonable obstacle-avoiding trajectories in obstacle and windy environments. The simulation results show that high-speed wind fields increase the flight time and fluctuation of control inputs. If boundary-layer wind field exists, the trajectory deforms significantly and gets closer to the ground to escape from the strong wind.

The key innovations in this paper include a cubic obstacle model which is straightforward and practical for trajectory planning and MUH trajectory planning in steady uniform wind field and boundary-layer wind field. This study provides an efficient solution to the trajectory planning for MUH in obstacle and windy environments.

Applying discrete linear optimal control to robot manipulators faces two challenging problems, namely nonlinearity and uncertainty. This paper aims to overcome nonlinearity and uncertainty to design the discrete optimal control for electrically driven robot manipulators.

Two novel discrete optimal control approaches are presented. In the first approach, a control-oriented model is applied for the discrete linear quadratic control while modeling error is estimated and compensated by a robust time-delay controller. Instead of the torque control strategy, the voltage control strategy is used for obtaining an optimal control that is free from the manipulator dynamics. In the second approach, a discrete optimal controller is designed by using a particle swarm optimization algorithm.

The first controller can overcome uncertainties, guarantee stability and provide a good tracking performance by using an online optimal algorithm whereas the second controller is an off-line optimal algorithm. The first control approach is verified by stability analysis. A comparison through simulations on a three-link electrically driven robot manipulator shows superiority of the first approach over the second approach. Another comparison shows that the first approach is superior to a bounded torque control approach in the presence of uncertainties.

The originality of this paper is to present two novel optimal control approaches for tracking control of electrically driven robot manipulators with considering the actuator dynamics. The novelty is that the proposed control approaches are free from the robot's model by using the voltage control strategy. The first approach is a novel discrete linear quadratic control design supported by a time-delay uncertainty compensator. The second approach is an off-line optimal design by using the particle swarm optimization.

The purpose of this paper is to present a separable identification algorithm for a multiple-input single-output (MISO) continuous-time (CT) system.

This paper proposes an optimal method for the identification of MISO CT systems with unknown time delays by using the Simplified Refined Instrumental Variable method.

Simulations results are presented to show the performance of the proposed approach in the presence of additive output measurement noise.

This paper presents an optimal and robust method to separable delays and parameter identification of a MISO CT system with unknown time delays from sampled input/output data.

To design effective and practical controllers that use the adaptive fuzzy approaches and are applicable to helicopters.

Based on Takagi‐Sugeno fuzzy systems, a new direct adaptive fuzzy control scheme is developed for a class of nonlinear multiple‐input‐multiple‐output systems. A simple observer is designed to generate an error signal for the adaptive law. The system states of the system are not required to be available for measurement.

The overall adaptive scheme guarantees all the signals involved being uniformly bounded in the Lyapunov sense.

The implementation of this research work needs further investigation.

The simplicity of the design algorithm facilitates the application of the design to helicopters by the use of Matlab.

Experimental results of a two degree of freedom helicopter are presented to confirm the usefulness of the proposed new control scheme.

Considers the mathematical modelling of sewing machines. The machine with a rotary hook and with a feed mechanism driven by two triangle cams is studied. The behaviour of the system is described by a set of non‐linear autonomous ordinary differential equations. It is shown that, due to the timing belt extensibility, the actual relative position of the needle and the hook is different from that expected. This difference is a result of the conflict between the almost constant speed of the hook shaft and the fluctuating speed of the crank‐shaft caused by the reciprocating motion of working elements. The vibration of the belt increases with speed. Resonance increase of vibrations takes place when the shaft speed is equal to natural frequency or its fraction 1/n for n = 1, 2, 3, 4, 5.

The purpose of the paper is to present an approach to detect and isolate the aircraft sensor and control surface/actuator failures affecting the mean of the Kalman filter innovation sequence.

The extended Kalman filter (EKF) is developed for nonlinear flight dynamic estimation of an F‐16 fighter and the effects of the sensor and control surface/actuator failures in the innovation sequence of the designed EKF are investigated. A robust Kalman filter (RKF) is very useful to isolate the control surface/actuator failures and sensor failures. The technique for control surface detection and identification is applied to an unstable multi‐input multi‐output model of a nonlinear AFTI/F‐16 fighter. The fighter is stabilized by means of a linear quadratic optimal controller. The control gain brings all the eigenvalues that are outside the unit circle, inside the unit circle. It also keeps the mechanical limits on the deflections of control surfaces. The fighter has nine state variables and six control inputs.

In the simulations, the longitudinal and lateral dynamics of an F‐16 aircraft dynamic model are considered, and the sensor and control surface/actuator failures are detected and isolated.

A real‐time detection of sensor and control surface/actuator failures affecting the mean of the innovation process applied to the linearized F‐16 fighter flight dynamic is examined and an effective approach to isolate the sensor and control surface/actuator failures is proposed. The nonlinear F‐16 model is linearized. Failures affecting the covariance of the innovation sequence is not considered in the paper.

An approach has been proposed to detect and isolate the aircraft sensor and control surface/actuator failures occurred in the aircraft control system. An extended Kalman filter has been developed for the nonlinear flight dynamic estimation of an F‐16 fighter. Failures in the sensors and control surfaces/actuators affect the characteristics of the innovation sequence of the EKF. The failures that affect the mean of the innovation sequence have been considered. When the EKF is used, the decision statistics changes regardless the fault is in the sensors or in the control surfaces/actuators, while a RKF is used, it is easy to distinguish the sensor and control surface/actuator faults.

The purpose of this paper is to propose an adaptive robust controller for coupled attitude and orbit control of rigid spacecraft based on dual quaternion in the presence of external disturbances and model uncertainties.

First, based on dual quaternion, a theoretical model of the relative motion for rigid spacecraft is introduced. Then, an adaptive robust controller which can realize coordinated control of attitude and orbit is designed in the existence of external disturbances and model uncertainties.

This paper takes advantage of the Lyapunov function which can guarantee the asymptotic stabilization of the whole system in the existence of parameters uncertainties. Simulation results show that the proposed controller is feasible and effective.

This paper proposes a coupled attitude and orbit adaptive robust controller based on dual quaternion. Simulation results demonstrate that the proposed controller can achieve higher control performance in the presence of parameters uncertainties.

The paper aims to achieve translational shaking tests on a 6-DOF hydraulic parallel manipulator. Shaking tests are commonly performed on shaking tables, which are generally used for small motion ranges and are usually financially costly. The research is required to generate shaking motions in three translational directions for a specimen for shaking tests, but it also needs to produce 6-degree of freedom (DOF) motions with large motion ranges.

A hydraulic 6-DOF (degree of freedom) parallel manipulator is applied to achieve this goal. The link-space control is adopted for the manipulator, and PID controller and feed-forward controller are used for each loop of the system. A hybrid reference signal generator is proposed by using a shaking controller, which is developed to convert the shaking motion into position signal. The converted result is directly added to the pose signal. The whole real-time control system is realized by using MATLAB xPC Target.

The developed method is verified on the hydraulic 6-DOF parallel manipulator with specimen. Experiments show very promising results that the proposed technology is really applicable to perform translational shaking tests on the hydraulic parallel manipulator.

A simple yet efficient solution is proposed that allows shaking tests in three translational directions performed on the hydraulic 6-DOF parallel manipulator with wide motion ranges. The paper presents a state-of-the-art related to the applications of parallel robots in several fields of technology.

Though social trends are driving consumers toward solo consumption of various services, many are reluctant to do so. There is little guidance for service providers as to how to effectively induce solo consumption. This study aims to examine the joint effect of self-esteem and an incidental similarity cue (e.g. a person’s initials) on anticipated satisfaction with with a solo consumption experience to fill this gap.

This study used a two-factor (incidental similarity cue and self-esteem) quasi-experimental design to test the hypotheses. The respondents read a scenario depicting a solo service consumption experience and completed scales that measured perceived fit with the service context and anticipated satisfaction with the experience.

Results indicate that, in the absence of an incidental similarity cue, self-esteem has a positive effect on solo consumers’ perceived fit. In the presence of such a cue, however, self-esteem has a minimal impact on perceived fit. Furthermore, perceived fit mediates the effect of self-esteem on anticipated satisfaction when the cue is absent.

The authors’ findings suggest that promoting incidental similarities with consumers may not be an efficient strategy to attract solo consumers. Conversely, service providers wishing to induce solo consumption may benefit from situationally increasing self-esteem among potential solo consumers. The current research advances the authors’ understanding of the effect of an incidental similarity cue and self-esteem in the context of a growing social trend of solo consumption.

The purpose of this paper is to develop a general mathematical model for the evaluation of the bending and vibration responses of the skew sandwich composite plate using higher-order shear deformation theory. The sandwich structural components are highly preferable in modern engineering application because of their desirable structural advantages despite the manufacturing and analysis complexities. The present model is developed to solve the bending and vibration problem of the skew sandwich composite plate with adequate accuracy numerically in the absence of the experimental analysis.

The skew sandwich composite plate structure is modelled in the present analysis by considering laminated face sheet in conjunction with isotropic and/or orthotropic core numerically with the help of the higher-order mathematical model. Further, the responses are computed numerically with the help of in-house computer code developed in matrix laboratory (MATLAB) environment in conjunction with finite element (FE) steps. The system governing equations are derived via variational technique for the computation of the static and the frequency responses.

The skew sandwich composite plate is investigated using the higher-order kinematic model where the transverse displacement through the thickness is considered to be linear. The convergence and the validation study of the bending and the frequency values of the sandwich structure indicate the necessary accuracy. Further, the current model has been used to highlight the applicability of the higher-order kinematics for the evaluation of the sandwich structural responses (frequency and static deflections) for different design parameters.

In the present paper, the bending and the vibration responses of the skew sandwich composite plate are analysed numerically using the equivalent single-layer higher-order kinematic theory for the isotropic and the orthotropic core numerically with the help of isoparametric FE steps. Finally, it is understood that the present model is capable of solving the sandwich structural responses with less computation cost and adequate accuracy.