Design And Power Experiment Of Dual-Motor Crawler Chassis For Combine Harvester

In order to realize the intellectualization of rice combine harvester conveniently,a dual-motor driven tracked chassis that is suitable for small and medium-sized rice combine harvester is designed.The main research contents and achievements are as follows:(1)Analysis of and maneuverability of crawler chassis.Firstly,the straight-line driving principle of track chassis is analyzed.The relationship between theoretical speed,actual speed and parameters are calculated.Secondly,the relationship between the driving force of the crawler chassis and the parameters under two conditions which are the rotating center falling in the inside and the outside of the crawler's tracks are analyzed.Finally,the performance and failure of the crawler chassis are analyzed.It can provide experimental basis for the overall structural design and simulation analysis of the crawler chassis of the dual-motor rice combine harvester.(2)The overall structural design of the dual-motor crawler chassis of the rice combine harvester.Based on the results of the maneuverability analysis of the tracked vehicle,based on the theory of agricultural machinery manual,the design principle of the tracked vehicle and the mechanical design,combined with the working conditions and working environment of the rice harvesting field,by using the software such as Solidworks and CAD.The rice harvester dual-motor crawler chassis is designed,which includes running system,power system and transmission system.The prototype was processed and manufactured.(3)Design of crawler chassis remote control system and power measurement system for dual-motor rice combine harvester.In this chapter,a remote control system and a power measurement system are designed for the dual-motor rice combine harvester crawler chassis.The design of the remote control system includes hardware of drive circuit of motor,the software and hardware design of the signal transmitting part and the signal receiving part of the remote control system.The theoretical maximum remote control distance is 1000 m.The design of the power measurement system includes the hardware design of the current measurement circuit,the hardware design of the voltage measurement circuit,and the software design of the power measurement system.Which can provide a platform for controlling tracked chassis and subsequent driving power test.(4)Simulation test of single-side crawler drive power of crawler chassis of dual-motor rice combine harvester based on MATLAB/SIMULINK.The model of the DC brushless motor drive system is established in MATLAB/SIMULINK software.As thebrushless DC motor is the driving component of the crawler chassis,according to the driving principle of the DC brushless motor,a mathematical model is established,based on the analysis of maneuverability of the crawler chassis in the second chapter.In this model,single-side track at different traveling speeds(0.6m/s,0.8m/s,1.0m/s,the whole machine mass is 600kg),different masses(680kg,760 kg,840kg,920 kg,1000kg,the whole machine traveling speed is 0.6m / s)and the average driving power in the case of in-situ steering(the whole machine mass is 600 kg.Traveling speed is 0.6m / s)are simulated.The simulation results show that the lower the motor speed and the larger the load are,the greater the fluctuation of the motor output torque will be..(5)Dual-motor rice combine harvester crawler chassis cement road and field test.The driving speed of the crawler chassis of the dual-motor rice combine harvester to PWM duty cycle test and the yaw rate test were carried out on the cement road.At the same time,the same influencing factors were tested on the cement road and the field soil.The average driving power was tested at different traveling speed(0.6m/s,0.8m/s,1.0m/s,whole machine mass 600kg),different masses(680kg,760 kg,840kg,920 kg,1000kg,whole machine traveling speed 0.6m/s)and in-situ steering(600 kg of the whole machine mass and traveling speed 0.6 m/s).The test results show that: 1)the running speed of the PWM square wave 70%,80%,90% on the cement road corresponding to traveling speed0.644m/s,0.836m/s,1.050m/s.2)the straight deviation rate on the cement road is 2.7%,which meets the national standard requirements ?6%;3)The same test is carried out on the flat cement road and on the field soil ground,the average soil solidity of field soil is1331 kPa and the average soil moisture content rate is 17.85%.The motor driving power tests at different speeds and masses are carried out.The single-factor test result shows that the speed has the most significant impact on the driving power of the motor,mass has less significant impact on the driving power of the motor.The comparison of the data of cement road test,field trial and simulation showed that the cement road,field and simulation steering load ratio are 2.14,2.26,and 2.56.Respectively,in the speed test,the ratio of cement road to field straight driving power decreases from 0.74 to 0.58.In the mass test,the ratio of cement road to field driving power has maintained at around 0.68.