In this paper, we present an alternate method for the generation and implementation of the sensor measurement variance used in an Extended Kalman Filter (EKF). Furthermore, it demonstrates the limitations of a conventional EKF implementation and postulates an alternate form for representing the sensor measurement variance by extending and improving the characterisation methodology presented in the previous work. As presented in earlier work, the use of surveying grade optical measurement instruments allows for a more effective characterisation of Ultra-Wide Band (UWB) localisation sensors; however, in cluttered environments, the sensor measurement variance will change, making this method not robust. To compensate for the noisier readings, an EKF using a model based sensor measurement variance was developed. This approach allows for a more accurate representation of the sensor measurement variance and leads to a more robust state estimation system. Simulations were run using synthetic data in order to test the effectiveness of the EKF against the originally developed EKF; next, the new EKF was compared to the original EKF using real world data. The new EKF was shown to function much more stably and consistently in less ideal environments for UWB deployment than the previous version.
A new hierarchical control strategy for active hydropneumatic suspension systems is proposed. This strategy considers the dynamic characteristics of the actuator. The top hierarchy controller uses a combined control scheme: a genetic algorithm- (GA-) based self-tuning proportional-integral-derivative controller and a fuzzy logic controller. For practical implementations of the proposed control scheme, a GA-based self-learning process is initiated only when the defined performance index of vehicle dynamics exceeds a certain debounce time threshold. The designed control algorithm is implemented on a virtual prototype and cosimulations are performed with different road disturbance inputs. Cosimulation results show that the active hydropneumatic suspension system designed in this study significantly improves riding comfort characteristics of vehicles. The robustness and adaptability of the proposed controller are also examined when the control system is subjected to extremely rough road conditions.
This case study describes in depth the actions and processes associated with implementing the Classroom Strategies Coaching (CSC) model with a 3rd-grade teacher, Sara. The CSC model uses formative assessment data to support teachers' use of evidenced-based instructional and behavior management practices. The CSC model took place across 8 weeks in a high poverty school. Findings highlight increased use of behavior praise and concept summaries by Sara (single subject effect sizes of 8.49, .56) and reduced need for practice changes in academic performance feedback and behavior praise (as measured by Classroom Strategies Assessment System discrepancy scores [i.e., Α recommended fre-quencyϪobserved frequency]; effect sizes of Ϫ1.21, Ϫ1.77). Improvements in student academic engagement (effect size of 2.55) and teacher reported instructional support were also found.
Impact and ImplicationsThis article presents the Classroom Strategies Coaching model that integrates unique scores (i.e., frequency and quality of strategy use) from multiple observations to identify teacher practice needs and goals, design support plans, and evaluate progress toward goals. Coaches model and practice the implementation of evidence-based instructional and behavior management practices and provide visual performance feedback to teachers via coaching. The application of the model is described in a case of a third-grade teacher employed in a high poverty elementary school. Independent observers rated improvements in teacher use of behavior praise, concept summaries, and academic performance feedback, as well as student academic engagement at postintervention.
This study directly addresses the problem of optimal control of a structure under the action of moving masses. The main objective of the study is to experimentally implement and validate an active control solution for a small-scale test stand. The supporting structure is modeled as an Euler-Bernoulli simply supported beam, acted upon by moving masses of different weights and velocities. The experimental implementation of the active controller poses a particular set of challenges as compared to the numerical solutions.
It is shown both numerically and experimentally that using electromagnetic actuation, a reduced order controller designed using a time-varying algorithm provides a reduction of the maximum deflection up to 18% as compared to the uncontrolled structure. The controller performance and robustness were tested against a representative set of possible moving load parameters.
In consequence of the variations in moving mass weight and speed the controller gain requires a supplementary adaptation. A simple algorithm that schedules the gain as a function of the weight and speed of the moving mass can achieve both a good performance and an adjustment of the control effort to the specific design requirements.
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