A control task’s performance heavily depends on its sampling frequency and sensing-to-actuation delay. More frequent sampling, that is, shorter period, improves the control performance. Similarly, shorter delay also has a positive effect. Moreover, schedulability is also a function of periods and deadlines. By taking into account the control performance and schedulability at the same time, this paper defines a period and deadline selection problem for fixed-priority systems. Our problem is to find the optimal periods and deadlines for given tasks that maximize the overall system performance. As our solution, this paper presents a novel heuristic algorithm that finds a high-quality suboptimal solution with very low complexity, which makes the algorithm practically applicable to large size task sets.

In this paper, we propose a performance-aware workload model for efficient implementation of control systems. When implementing a control algorithm as an embedded computer system, the control code executes periodically. For such systems, its control performance depends on not only the accuracy of the control algorithm itself but also temporal parameters such as control period and sensing to actuation delay. In this regard, this paper studies the relation between control period and delay by measuring and analyzing the control performance of LKAS (Lane Keeping Assist System) with varying period and delay combinations. Through this experimental study, this paper shows that the two timing parameters, i.e.,control period and delay, has a tradeoff relation in terms of control the Department of Computer Science at

Lumber spine range of motion has been used to measure of physical and functional impairment by various tools from a ruler to 3D kinematic devices. However, pre-existing tools have problems in either movement or accuracy and reliability limitations. Accurate devices are limited by fixed space whereas simple devices are limited in measuring complex movements with less accuracy. In order to solve the location, movement and accuracy limitations at once, we have developed a novice measurement device equipped with accelerometer sensor and gyroscope sensor for getting three-dimensional information of motion. Furthermore, Kalman filter was applied to the algorithm to improve accuracy. In addition, RF wireless communication was added for the user to conveniently check measured data in real time. Finally, the measurement method was improved by considering the movement by a reference point. An experiment was conducted to test the accuracy and reliability of the device by conducting a test-retest reliability test. Further modification will be conducted to used the device in various joints range of motion in clinical settings in the future.