The recently developed stable inversion theory for nonminimum phase nonlinear systems is applied to output tracking for multilink exible robot manipulators. The stable inversion theory and a numerical solution to stable inverses are brie y reviewed. Forward dynamics of a two-link exible manipulator with tip position as the output is then given using the assumed modes method. From that, an inverse model is derived and a two-point boundary value condition is set up. This condition guarantees that the inverse solution for a given desired tip trajectory will be stable regardless of the fact that a exible manipulator is a nonminimum-phase system. The stable inverse is incorporated into an output tracking controller that uses only joint-angle feedback. Excellent tracking is achieved with no transient or steady-state errors and no internal vibration buildup.

Aiming at the problem of falling easily into local optimal solution of conventional particle swarm optimization algorithm, an adaptive particle swarm optimization algorithm is proposed, which adaptively adjusts the values of inertial weight and two learning factors in the iterated search process. The environment model of path planning is built for unmanned aerial vehicle (UAV) to perform reconnaissance task in mountain environment. The self-constraint conditions of UAV are analyzed. The fitness degree function of adaptive particle swarm optimization algorithm and flow chart of path planning algorithm are designed. The simulation experiments of three dimensional path planning of UAV are carried out by adopting respectively the adaptive particle swarm optimization algorithm and the conventional particle swarm optimization algorithm. The contrast of simulation result shows that the proposed adaptive particle swarm optimization algorithm has higher global search ability and search precision than the conventional particle swarm optimization algorithm.

PurposeCompetitiveness of pharmaceutical companies hugely depends on new knowledge because of ever-changing technologies and forefront of knowledge. Leadership styles appear to influence knowledge management behavior, but there has been little empirical research on employees' knowledge creation behavior as an outcome of leadership. The study examines how task-oriented leadership affects subordinates' knowledge creation behavior. Based on organismic integration theory (OIT), the study proposes that perception of competitive climate and achievement motivation can conduct as mediators.Design/methodology/approachData were collected from 877 full-time working employees in five pharmaceutical companies in China. Participants answered demographic questions and completed the task-oriented leadership, perception of competitive climate, achievement motivation, as well as knowledge creation behavior scale. Structural equation modeling was used to test the hypothesized relationships.FindingsThe results review that task-oriented leadership will significantly promote subordinates' knowledge creation behavior. Perception of competitive climate and achievement motivation play mediator roles between task-oriented leadership and subordinates knowledge creation behavior. Perception of competitive climate and achievement motivation have a serial mediating effect between task-oriented leadership and subordinates knowledge creation behavior.Practical implicationsBy adopting a task-oriented leadership style through training and development, leaders may stimulate employees more knowledge creation behaviors by transmitting the organization's vision, clarifying their work tasks and setting relatively high-performance standards. Then, organizations should establish a competition mechanism to promote competition among employees, while also preventing malicious competition. Finally, organizations should arouse employees' achievement motivation to stimulate their internal pursuit of success and needs.Originality/valueBecause of the improvement of information technology and the acceleration of knowledge dissemination, the need for new knowledge is becoming more and more urgent in organizations. Knowledge, as a resource that needs to be managed in an organizational environment, has regained researchers' attention. However, a flourishing number of studies explain the organizational knowledge management from the macro level, there is a need to explore how leaders influence their subordinates to create knowledge. From the perspective of extrinsic motivation internalization, this study’s findings contribute to the literature on task-oriented leadership and knowledge creation behavior and expand our understanding of why task-oriented leadership promotes subordinates' knowledge creation behavior.

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Existing works on control of tractor-trailers systems only consider the kinematics model without taking dynamics into account. Also, most of them treat the issue as a pure control theory problem whose solutions are difficult to implement. This paper presents a trajectory tracking control approach for a full-scale industrial tractor-trailers vehicle composed of a carlike tractor and arbitrary number of passive full trailers. To deal with dynamic effects of trailing units, a force sensor is innovatively installed at the connection between the tractor and the first trailer to measure the forces acting on the tractor. The tractor's dynamic model that explicitly accounts for the measured forces is derived. A tracking controller that compensates the pulling/pushing forces in real time and simultaneously drives the system onto desired trajectories is proposed. The propulsion map between throttle opening and the propulsion force is proposed to be modeled with a fifth-order polynomial. The parameters are estimated by fitting experimental data, in order to provide accurate driving force. Stability of the control algorithm is rigorously proved by Lyapunov methods. Experiments of full-size vehicles are conducted to validate the performance of the control approach. arXiv:1909.11897v1 [eess.SY]