A Model for Automatic Control of Vibratory Plate Compactor
of the most Application of automatic control into compaction eglenineering works. This isoduel to problem compared with other machines used in civil g the difficulties in getting proper feedback, consisting of a transfer to the compactor and information on the state of the soil being just under compaction. The The paper presents an approach to this difficult and practically ti p ort nt p h have been discussion contains evaluation of several different responses possibility of a1 in information on g used so far in compaction analysis. compactor without Additionally, involving mathematical model of soil is mechanical behaviour of c pacto considered.
Simulation of Soil-Compaction with Vibratory Rollers
Most frequently, vibratory rollers are used for compaction tasks during earth works and road construction. An increase in roller performance can be achieved by automatically adapting the machine's parameters which determine the compaction result and by automatically controlling the state of compaction continuously. The actual problem is, that because of the extensive variety in properties of the materials to be compacted and the conditions in job site, it is very difficult to state the criteria for the feedback control of the roller parameters. By means of modelling and simulating, the vibration behaviour and compaction effect as well as the interdependence between the state of roller-operation and the state of soil-compaction is investigated. The goal is to aquire knowledge about the interactions between vibratory rollers and soil during compaction in order to improve roller construction and automatic compaction measuring-systems.
Traceability strategy for gear-pitch-measuring instruments: development and calibration of a multiball artifact
There is a strong demand to ensure the traceability of gear-measuring instruments (GMIs). We propose a multiball artifact (MBA) for the evaluation of pitch-measuring accuracy. The aim of the MBA is to transfer the minimum uncertainty from a calibrated value at the National Metrology Institute of Japan (NMIJ) to a measured value of GMIs at a shop floor. The MBA is composed of equally spaced high-accuracy balls around an axis. The pitch-measuring accuracy of GMIs is evaluated by measuring the angular pitch deviation of the balls instead of the angular pitch deviation of a gear. We calibrated the angular pitch deviation using a coordinate measuring instrument (CMM) at the NMIJ and adapting a multiple-orientation technique. We proposed a calibration strategy of the angular pitch deviation. The calibration value of the pitch deviation for the MBA at the NMIJ was obtained with a measurement uncertainty (U95) of 0.2 µm. We evaluated the pitch-measuring accuracy of a GMI using the calibrated MBA. Each value of U95 for the cumulative and single pitch deviations for the left and right flanks was less than or equal to 0.5 µm. The small uncertainty was transferred from the NMIJ to the GMI.