Design and experiment of electromechanical and hydraulic coupling brake system for underground hybrid trackless rubber tired vehicles

The trackless rubber tired vehicle (TRTV) is a kind of auxiliary transportation vehicle used for underground mining environment. It is pretty difficult to achieve stable braking performance for a hybrid TRTV with a single braking method and control strategy. Firstly, the structure of electromechanical and hydraulic coupling brake system was designed by taking the hybrid TRTV as research object. Then, the control circuit of its hydraulic brake system was determined, and the control strategy was designed according to the braking regulations of the Economic Commission for Europe (ECE). Next, a simulation comparison test was conducted, in which the battery initial SOC values was 0.7 and 0.85 respectively. And the brake system established in this paper was compared with the one in the ADVISOR under the working condition of CYC-WCQ1. Finally, the feasibility of the coupling brake system designed in this paper was verified by bench testing. The error difference between the simulation test and the bench test results was within the allowable range. The fuel consumption of the bench test is 12.38% and 13.33% higher than that of the simulation test, the HC emissions are 11.48% and 13.55% higher, the CO emissions are 10.24% and 10.75% higher, and the NOx emissions are 9.01% and 9.74% higher respectively. It is believed that this research may be valuable for both the development of reliable brake system for hybrid TRTVs used in mining industry.