| As an important equipment in the mining process,the disc brake system applies the brake to hoist by clamping the brake disc with the brake shoe.The disc brake has fast response speed,large braking force and stable performance.This paper presents an electromechanical disc brake system applied in the field of mine hoist braking.The brake improves the problems of traditional brake oil leakage,inaccurate brake force control,and difficult brake gap adjustment.In this paper,the structure of the brake system is designed,the dynamics is analyzed,the controller is designed,the test platform is built,and the working performance of the brake is tested through a series of tests.First of all,this paper has fully investigated the research status of hoist brake at home and abroad,and summarized the advantages and disadvantages of brakes with different structures.Combined with the characteristics of electromechanical brake in other fields,the electromechanical disc brake system of mine hoist is proposed.The braking system consists of actuator and controller.The actuator uses the motor as the power source.The brake adopts the motor,ball screw,disc spring and brake shoe mechanism,realizing the easy control and normally closed working characteristics of the actuator.According to the braking requirements of a certain type of mine hoist,this paper has completed the structural design and model selection of the main parts of the actuator from the motor to the brake shoe.Secondly,the dynamics analysis of the brake system actuator is carried out in this paper.The driving model and friction model of torque motor are deduced.Based on the Lagrange equation,the 8 degrees of freedom dynamic model of planetary gear reducer is analyzed.The theoretical derivation of the dynamic equations for the sun gear,planet gear and planet carrier is carried out respectively.The high order deceleration and torsion model of the reducer is obtained.The stress state of the load model is analyzed.The dynamic equations of screw and brake shoe are established.Then,three closed-loop control strategies are designed for braking force and brake gap in this paper.The advantages and disadvantages of classical PID are discussed.The design processes of fuzzy PID and genetic algorithm PID(GA-PID)are sorted out.The simulation calculation of brake under the control of three algorithms is established in Simulink,and the simulation study is carried out for the control effects of braking force and brake gap.The control effects of different controllers are compared and analyzed.The closed-loop brake control transient process is simulated,and the key parameters of the controller are rectified in the program simulation.The simulation results show that the control effect of GA-PID is better,and the performance of brake control system meets the design requirements.Finally,the brake system test platform is designed.Parts processing and hardware selection are completed.The hardware in the loop test system based on c SPACE is established.The torque motor characteristic test and brake system closed-loop control test are carried out.The advantages and disadvantages of control effects under different controllers are analyzed and discussed.Figure [68] Table [21] Reference [83]... |
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