Track gauge dynamic measurement based on 2d laser displacement sensor
Track irregularities can cause deterioation of riding comfort and derailment. Track gauge variation is one of the basic track irregularities. Track Recording Car is an automated track inspection vehicle on a rail transport system used to test several geometric parameters of the track. Track geomeotry parameters generally measured include position, speed, gauge, alignment, crosslevel, curvature and so on. This paper presents a novel technique for the measurement of track gauge variation, a new measurement system was introduced and been in assembled on a new type underground track recording car.
Research on the Gauge Sensor Laser Spot
Based on the quadrant photodiode detector and triangulation method,a novel laser displacement sensor wis proposed for the gauge measurement.The laser sensor adopts the infrared laser and the quadrant photodiode to avoid the disturb.To adjust the infrared laser to the optimal place,we analyze and calculate the relation between the laser spot and the laser place.
Recalculation of Mass Defects
THE well-known mass defect curve of the old nuclear scheme calculated with regard to α-particles and protons presented a difficulty with its minimum of binding energy for tin and an increasing portion between tin and lead. On the other hand, the mass defect values against protons give a rather smoothly decreasing curve.1 As has already been pointed out,2 the number of α-particles must be considerably reduced from the point of view of the new scheme, which does not admit any electrons in nuclei, but only neutrons and protons (presumably joined as α-particles). The curve of mass defect against protons and neutrons (perhaps with a single ‘central’ α-particle) is very similar to the old curve against protons, but decreases less rapidly. Clearly the new mass defect values relatively to α-particles, neutrons and protons must lie somewhere between the old values computed relative to protons and α-particles respectively (because the number of α-particles is decreased). We may emphasise that this new mass defect curve shows no increasing portion between tin and lead. For illustration we give two typical values: Old: 50Sn124 = 31α + 12&#38;epsiv;; mass defect = 0.158 (in mass units); 82Pb208 = 52α + 22&#38;epsiv;; mass defect = 0.035. New: 50Sn124= 25α + 24ω (ω = neutron); mass defect = 0.304; 82Pb208 = 41α + 44ω; mass defect = 0.366.