## 2 Literature Review
### Temporary Support Equipment for Roadway  
Temporary support equipment for a roadway refers to the equipment used to temporarily support the wall rock of the roadway, ensure the stability of the roadway wall rock, prevent roof collapse, and protect the safety of operators during roadway excavation. Many scholars have studied different forms of temporary support methods and their corresponding equipment  
(1) Forepoling bar temporary support  
A forepoling bar temporary support belongs to the passive support mode [8]. Generally, an I-beam for mining is used as the forepoling bar, which is suspended on the roof bolt in the support area and is probed to the newly cut, empty roof area along the direction of the roadway axis. The gap between the forepooling bar and the roof is filled with wooden wedges to ensure the contact between them. The forepoling bar support has a certain protection effect on the roadway roof, the required equipment is simple, and the cost is low. However, the disadvantages of this support method are a poor support effect, complex erection process, long manual operation time, and low support efficiency [9]. Before the permanent support is completed, the rock mass has produced plastic deformation, which cannot effectively prevent roof accidents such as a roadway roof fall, and the support effect is not ideal [10]. During the erection of the forepoling bar support, the staff carry out the operation under the empty roof area, which makes it difficult to ensure the safety of the construction personnel [11]. (2) Machine-mounted temporary support  
A machine-mounted temporary support is based on the roadheader and driven by the hydraulic cylinder, which is erected on the top of the roadheader to improve the adaptability of the temporary support to the roadway [12]. [PERSON] et al. [13] developed a new type of machine-mounted temporary support in view of the problems existing in the temporary support with a forepoline bar. This equipment was designed with an integral shield beam and could operate alternately with the roadheader. Compared with the forepoline bar temporary support, this equipment was simple to operate and could exert an initial support force on the roadway roof, improve the roadway footage speed, and reduce the labor intensity of workers. Aiming at the problem of the long auxiliary time of bolt support in fully mechanized roadway excavation, [PERSON] [14] developed a machine-mounted hydraulic temporary support composed of a guard plate, hydraulic cylinder, telescopic bar, and connecting rod. This equipment greatly improved the bolt support efficiency of the excavation head and the safety assurance system of the heading, improved the automation of the temporary support, and realized the rapid excavation of the roadway. [PERSON] et al. [15] proposed a side slide temporary support. A telescopic guideway was installed on both sides of the roadheader, which was driven by a hydraulic cylinder. The temporary support moved to the empty roof area in front of the cutting section of the roadheader under the push of the telescopic guideway. A hydraulic cylinder was supported on the roadway floor, and the main guard plate contacted the roadway roof and provided the support force for it, which solved the problem that the support force of the temporary support on the roadway roof was limited by the advance's support distance. [PERSON] [16] developed a kind of temporary support matched with the EBZ160 roadheader, which could work under low roof conditions and solved the problem of the poor adaptability of the temporary support to a low roof roadway. [PERSON] et al. [17] improved the side guard pin mounting base of a machine-mounted temporary support, reinforced it for the second time and designed a removable side guard mounting device, which solved the problem of the mounting base's variability and fracture.