This report presents the results of a key comparison of liquid volume measurement conducted between ten participating institutes during the period July 2006 to August 2008 within the framework of the Asia Pacifica Metrology Program (APMP). The transfer standards comprised one 20 L volume measure and two 100 mL glass pycnometers. These transfer standards had been used in a similar CIPM key comparison CCM.FF-K4 in 2003 to 2005. The pilot institute was the National Measurement Institute, Australia (NMIA), which together with CENAM act as link laboratories to the CCM.FF-K4 comparison.Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

This paper presents the design method a proportional integral derivative (PID) controller with time-varying parameters for trajectory tracking of a mecanum-wheeled robot with a minor error. First, a nonlinear kinematic error model of the robot is established and linearized around the working point. Then a PID controller with time-varying parameters is designed based on this linear model. The coefficients of KP, KI, and KD control parameters are determined by trial and error technique to ensure that the robot moves along the desired trajectory with minimal error. A platform mecanum-wheeled mobile robot has been designed and manufactured to demonstrate the proposed controller. Simulation and experimental results are presented to verify the effective and accuracy of the proposed controller. It shows that can apply this research to control of a four mecanum-wheeled mobile robot in logistics services in practice.

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Relative sliding between two profiles in the contact point causes wearing out of the tooth profile. Aiming to evaluate influence of the geometrical dimension parameters of the pump rotor profile on the wear, in this paper, the authors established equation for determining slip coefficient from geometrical dimensions. Furthermore, the authors have investigated and evaluated the phenomenon of the profile slipping in order to find out the geometrical dimensional parameters for avoiding unequal wearing of the inner and outer rotors of the hypogerotor pump

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