It can be seen from the left panels of Figure 7 that the servomotor torque fluctuates for each data sample. During the last 34 days before maintenance, some impulses appear in the last half of the ball screw travel. As shown in the right panels of Figure 7, the spectrum plot of each data sample shows that the same dominating spectrum peaks appear at the servomotor’s rotary frequency and the first, second and third harmonics of the reducer meshing frequency, with very slight changes in the peaks’ value. At the same time, a resonance appears at the frequencies band between 330�C370 Hz, during the last 62 days before maintenance. Similar results occur in the spectrum of almost every data sample. Thus, it is not easy to describe the degradation progress by directly using the change of the characteristic frequencies.

Figure 7.Servomotor torque of X-axis at different number of the days before maintenance.To describe the degradation progress, the proposed BRWB is used to detect the quadratic nonlinear phase coupling frequencies band of the torque signature. Here, the bandwidth from 0�C500 Hz is selected for the bicoherence calculation. Figure 8a�Cd showS the BRWB of the torque data samples at 192 days, 62 days, 34 days and 2 days before maintenance, respectively. As shown in Figure 8a, it is found that the dominant phase coupling peaks appear at the bifrequency (32 Hz, 64�C350 Hz), which illustrates that, at the beginning of the service life progress, the quadratic nonlinear interaction only occurs between the 1th, 2th and 3the harmonics of the reducer’s meshing frequency.

As the service life progresses, new phase coupling presents at the bifrequency (64 Hz, 270 Hz) and (140 Hz, 230 Hz) as shown in Figure 8c,d, which illustrates that quadratic nonlinear interaction between the reducer’s meshing frequency and the resonance frequency band results from the degradation of the X-axis. In addition, the peaks value at the new bifrequency (64 Hz, 270 Hz) and (140 Hz, 230 Hz) are increasing as the degradation progresses.Figure 8.BRWB of X-axis servomotor torque data: (a) 192 days before maintenance; (b) 62 days before maintenance; (c) 34 days before maintenance; (d) 2 days before maintenance.To further investigate the interactions, the phase coupling distribution Carfilzomib of each data sample is estimated by using the SBRWB feature, as shown in Figure 9a, and the global phase coupling of each data sample is estimated by the MEBRWB feature as shown in Figure 9b. The differences among the BRWB of each data sample can be directly revealed by the SBRWB feature. The SBRWB features of the resonance frequency band, servomotor rotary frequency harmonics and the second harmonic of reducer meshing frequency are increasing significantly during the service cycle.

In this work, we have used the output power of an EFA fiber sensor made up a PCS fiber bundle. Then we have used a canonical variable incorporating the sensor’s and absorbing dye’s parameters to predict the response of the sensor by the aim of ANN because it can produce proper outputs for given inputs without any necessity to mathematical formulations between input and output data.2.?EFA Sensor MeasurementsThe sensing process based on EFA has been performed by using the arrangement in Figure 1 [23]. The sensor is adopted from a spectrophotometer, WPA S105, in which white light is created by a pre-focusing incandescent lamp and reaches a diffraction grating by reflecting off a mirror.

The diffraction grating is attached to a rotating rod and acts as a monochromator to set the wavelength required.

Thus, a wavelength selectable sensor is obtained.Figure 1.The arrangement for evanescent field absorption sensor [23].The sensing element was a bundle that consists of five plastic cladding silica (PCS) fibers as shown in Figure 2. The PCS fibers are especially suitable for evanescent field applications in chemical sensing because plastic claddings can easily be removed by mechanically or chemically and replaced by a suitable medium. The use of the bundle for sensing purposes doesn’t affect the sensitivity because the input and output power of the sensor will increase a factor of the fiber number in the bundle.

However, the bundle not only improves the coupling of the light into the fibers, but also increases the interaction surface, and makes the detection of the light at the bundle output better.

The fibers in the bundle are separated at the sensing region to allow Anacetrapib the whole of the evanescent field of each fiber in the bundle is accessed by the external solution. In this work, claddings of the PCS fibers in the bundle were mechanically removed in order to maximize the interaction between the evanescent field, which is created by the total internal reflection, and the chemical to be sensed. A fiber in the bundle, forming the sensing region, is shown in Figure 3.Figure 2.The PCS fiber in the bundle (PCS200A, Quartz&Silice, France).Figure 3.

The GSK-3 geometry of the sensing region.For absorption measurements, Bromophenol Blue (BPB) indicator dye filled into the cuvette was used for absorbing cladding material. BPB is an indicator dye whose color is blue near pH 7 and varies by changing the pH. The monochromator was adjusted at a wavelength of 590 nm since the BPB solution has an absorption peak near this wavelength.The sensor response (Pout/Pin) has been measured for different BPB concentrations by using the arrangement given in Figure 1 and results are given in Figure 4.

As shown in Figure 1, a near field telemetry device was used to measure the output torque on a propeller shaft in which a strain gauge with a 350 ohm full bridge was used as a torque sensor. Because tracked vehicles use a control method that divides the torque converter output torque into transmission and steering input torques, it is necessary to measure the speed of the final drive for calculating the torque converter output torque from the propeller shaft torque that should be calculated by dividing it into the existence of steering, transmission output torque (or ring gear torque), and steering torque (or sun gear torque). Figure 2 illustrates the installed encoder using the tool fabricated in this study.Figure 1.Torque sensor for the propeller shaft.Figure 2.Speed sensor for the final drive.

Engine rpms represent the degree of the duty applied to the engine during a vehicle��s operation and they are important data to calculate relative duties. To measure the engine rpm, a tacho-generator that generates voltages in proportion to the engine rpm in a vehicle, as shown in Figure 3, was used. In addition, the vehicle speed was measured using a VBOXII sensor with a GPS that consists of an antenna for receiving GPS signals and body and has the resolution of 20 km/h/V.Figure 3.Tacho-generator for the engine RPM measurement.The real-time transmission shifting stages during driving represent important information, not only about the duty level of the transmission on the measured road, operation distribution for each shifting stage, and shifting frequency, but also the reverse calculation of the torque converter output torque in a relative duties calculation process.

The shifting stage applied to the 000 tracked vehicle used a method that measures the shifting stages by measuring the pressure applied to a clutch solenoid for gear shifting generated in a shifting stage.2.2. ResultsIn general, it is necessary to consider a reference for the speed due to the significant change in the torque characteristics in actual powertrain systems, according to changes in vehicle velocities. In the civilian car industries, the vehicle speed that is determined by 90% of regular drivers is considered as a measurement speed for its corresponding roads.

Regarding the speed configuration for measuring the driving duty in the endurance test ground, GSK-3 this study configured the average driving speed presented in the previously performed endurance testing of tracked vehicles as a measurement speed for the subjective road.This study performed the measurement for three types of endurance test grounds and three mobility roads in army operation areas. In addition, the cross country course was configured as a loop type of road with about 3.0 km of length and 8 m of width as shown in Figure 4.