The parameters of the wheel-rail contact product in Desk two were employed
The components of the pneumatic brake unit for the HILS is ready employing a professional product discover more herefrom the concentrate on motor vehicle apart from for the electronic controller. The digital controller of the HILS method is accomplished using the MATLAB/Simulink application, the xPC goal board, and a desktop Pc to employ the control logic described in the previous section. The motor vehicle product, as nicely as the wheel-rail get in touch with product, is simulated in real-time making use of a .1 ms sampling time by implies of a high-overall performance dSPACE unit. Moreover, the sign conditioners are prepared to interface the control indicators with the actuator signals. Fig 7 displays a photo of the brake HILS technique developed in our laboratory.To run the brake HILS program, a braking circumstance was well prepared as follows. One intercity motor vehicle that runs at a support speed of one hundred fifty km/h on a straight rail with no irregularities was utilised, and the rail was operated in soaked circumstances. The parameters of the wheel-rail get in touch with model in Table 2 were utilised. The EB command was ordered by the driver at the support speed of a hundred and fifty km/h. The deceleration value of the emergency braking was set to 5 km/h/s. All the other parameters have values of the focus on railway vehicle, as revealed in Table 3.Fig 8 displays the experimental outcomes for the four wheel speeds and the four axle hundreds throughout unexpected emergency braking of the HILS system. These HILS benefits display that it normally takes approximately 30 s to end the teach completely when the EB command is given at a prepare pace of 150 km/h. The deceleration and braking forces in Fig 8 that have been produced by the HILS technique are satisfactory in look at of the specified braking functionality of the concentrate on train. There are particular braking behaviors at roughly four seconds, at which time wheel slide takes place in the second and fourth wheelsets and the WSP valves begin to operate. The cause wheel slides ended up observed in only the next and fourth wheelsets is that the required adhesion coefficient limit of the wheel was enhanced at the 2nd and fourth wheelsets since the axle load lowered owing to the bodyweight transfer throughout braking. In this HILS test, we utilized the variable friction coefficient μd amongst the disc and the pad instead of the constant friction coefficient μd0. The variable friction coefficient among the disc and the pad employed for unexpected emergency braking of the HILS method is revealed as a solid line in Fig 9. This curve indicates that the friction coefficient is higher at the preliminary phase of braking because of to the minimal temperature of the brake resources, and that it is substantial at the last phase of braking because of to the low friction pace compared with the friction coefficient of the intermediate stage of braking. As predicted by Eq , the variable friction coefficient μd was better than the continuous friction coefficient μd0, which was .38 for the current situation. Even although the experimental benefits of the dynamometer in Fig 2 can not be in comparison right with the predicted values in the reliable line of Fig 9 since of different abscissa, the lessen of the friction coefficient at the original stage of braking and the improve of the friction coefficient at the ultimate stage of braking in Fig nine demonstrate partly the validity of the proposed Eq .