This work proposes and demonstrates a strategy for planning smooth path-constrained timeoptimal trajectories for manipulators. Such trajectories are obtained by limiting the actuator jerks required by the planned motion.Existing planning strategies incorporate the smoothness requirement either as smoothness of the actuator torques or as smoothness of the joint trajectories. The smoothness requirement is desirable for reducing strain on robot actuators while still requiring low cycle times. In this work, the trajectory smoothness is de ned in the phase plane and the planning observes the limits on the actuator jerks.The solution proposed for determining the optimal trajectories consists of approximating the time optimal control problem by a nonlinear parameter optimization problem which is solved using the exible tolerance method. It is shown that the approximate solution converges to the time optimal motion when the actuator jerks become very high. iii a signi cantly shorter motion time with nearly the same tracking accuracy as a quintic polynomial. Based on the results in this work, actuator jerk limits are shown to provide an improved method of achieving a compromise between high tracking accuracy, smooth joint behaviour, and optimal motion time.

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This paper presents a method for determining smooth and time-optimal path-constrained trajectories for robotic manipulators. The desired smoothness of the trajectory is imposed through limits on the actuator jerks. The third derivative of the path parameter with respect to time, the pseudo-jerk, is the controlled input. The limits on the actuator torques translate into state-dependent limits on the pseudo-acceleration. The time-optimal control objective is cast as an optimization problem by using cubic splines to parameterize the state space trajectory. The optimization problem is solved using the flexible tolerance method.

Patients with end-stage renal disease (ESRD) have an increased risk of all-cause mortality. The prognostic value of the new cardiac biomarkers, cardiotrophin 1 (CT-1) and galectin 3 (GAL-3), has not yet been defined in hemodialysis (HD) patients. The aim of this study was to determine the use of these novel biomarkers for predicting mortality in HD patients. Plasma GAL-3 and CT-1 concentrations were determined (at baseline) in 88 HD patients followed for 22.2 ± 4.7 months. During the follow-up period, 21 (23.9%) deaths were recorded. According to Cox analysis, the cutoff point for GAL-3 as a predictor of mortality was 23.73 ng/mL, while the cutoff point for CT-1 as a predictor of mortality was 36 pg/mL. In univariate analysis, only GAL-3 >23.73 ng/mL was an independent predictor of mortality (hazard ratio 2.60; 95% confidence interval, 1.09-6.18). In a multivariable Cox proportional hazards model, GAL-3 levels above the cutoff value remained an independent predictor of all-cause mortality. Our data suggest that similar to the general population, GAL-3 is an independent predictor of mortality in HD patients.