Research To Optimize The Digging Trajectory Of Cable Shovels

Digging trajectory is an important research when designing cable shovel. A good trajectory can absolutely improve the production efficiency of the cable shovel. Especially when the the state is encouraged to develop Energy-Efficient Economy at present. It is an significant idea to improve the performance of the cable shovel by finding optimized trajectories.This paper makes research on the basis of 30 samples of testing data. Firstly, restore the discrete trafectory by founding the kinematic model. The most commonly used models at present is fixed point method by considering crowd gear center as the center of dipper handle’s rotation.This paper gives a new method called unfixed point method which considers the contact point of dipper handle’s pitch line and crowd gear’s pitch circle.as the center of rotation. The unfixed point method is gives a more accurate way to solve the dipper tooth’s trajectory. It also provides a better basic condition for optimized trajectory.Log spiral trajectory is the most widely used trajectory, it is convinent and intuitive. So in this paper, the log spiral will be used to fit the discrete trafectory. And then get the cutting angle of the trajectory.The attachment of the sholve suffers fickle loads; the solid in the dipper is anisotropy also. Those two features make it hard to solve the volume inside the the dipper. This paper analysis the component of of dipper and dipper handle by applying the Alembert principle. Eliminate the the inertia force caused by rotation. Then get the volume at each sample point between finished digging time and dumping time. After a comprehensive analysis, the volume inside the dipper is given. The result can be checked by considering the energy consumption and and the volume of the solid inside the dipper are positively related.To judge the optimized trajectory this paper gives three principles:firstly, the volume of the solid inside the dipper should be close to the rated volume of the dipper; secondly, the digging time should be in a rational range; finally, the energy per unit load consumed should be lowest. In accordance with those three principles, the 30 samples were optimized to two trajectories ρ=10.810e03975φ and ρ=9.45e0.4975φ. Each EPL of the two trajectories are 0.0945kJ/kg and 0.0981kJ/kg.