## 4 Simulation of Shovel Force
### Power Matching  
While the shovel force of the 35-ton EWL is predicted by the loading model, the power is matched according to the power requirements for the shovel force. The typical operation of the EWL is broken down into two working conditions for power matching, with speed and torque curves as shown in Figures 13 and 14.  
The condition of the EWL performing linear acceleration in first gear without a load is represented in Figure 13. Figure 13a displays the simulation curve of the speed variation during the no-load acceleration. According to empirical data, when the EWL is in first gear and accelerates in a straight line without a load, the torque is the same for all four wheels. Figure 13b shows the simulation curve of the torque variation for all four wheels during no-load acceleration.  
The simulation curves of the motor torque for the front and rear wheels of the full- load EWL during first-gear linear acceleration are depicted in Figure 14. The loaded condition involves simulating materials with a 35-ton block. According to the empirical data, when the EWL is no-load and accelerates in first gear, the torque for the front two wheels is the same, and the torque for the rear two wheels is also the same. Additionally, the torque for the front two wheels is greater than that for the rear two wheels. The torque for the front wheels constitutes approximately 70-75% of the total torque for all four wheels, while  
Figure 12: Power transmission path of 35-ton EWL.  
the torque for the rear wheels constitutes approximately 25-30%. Figure 14a shows the simulation curve of the torque variation for the front axle motor. When the EWL is no-load and accelerates in first gear, all four wheel torques are the same, as illustrated in Figure 14b, which presents the simulation curve of the torque variation for all four wheels during no-load acceleration.  
In typical scenarios, when the EWL is no-load, the power distribution between the front and rear axles is usually 50% for each. When the EWL is full-load, the power distribution is approximately 70-75% for the front axle and 25-30% for the rear axle. Table 3 presents the power-matching table for the EWLs. For no-load driving, the total power is 456 kW, with the sum of the power from the two front axle motors being 228 kW and the sum of the power from the two rear axle motors also being 228 kW. This results in an equal distribution of power between the front and rear axles, meeting the power-matching requirements. For full-load driving, the total power is 576 kW. The sum of the power from the two front axle motors is 426 kW, and the sum of the power from the two rear axle motors is 142 kW. In this scenario, the torque for the front wheels constitutes approximately 74% of the total torque for all four wheels, and the torque for the rear wheels constitutes approximately 26%, meeting the power-matching requirements.  
Figure 14: (**a**) Torque variation of front axle motors; (**b**) Torque variation of rear axle motors.  
Figure 13: (**a**) Speed variation curve during no-load acceleration; (**b**) Torque variation curve during no-load acceleration.  
Accurate prediction of the shovel force of large-tonnage loaders has enabled precise matching of the electric motors. Ultimately, by combining the dimensions of the bucket, the design of the bucket capacity, and the implementation of reduction control of shovel force, a rational torque distribution has been achieved.