In response to the problems of excessive greenhouse-gas and particulate emissions and the low traction efficiency of conventional diesel tractors in the field,a purely electric wheel-side drive tractor was studied,inc...In response to the problems of excessive greenhouse-gas and particulate emissions and the low traction efficiency of conventional diesel tractors in the field,a purely electric wheel-side drive tractor was studied,including an electric motor drive system,a battery ballast system,and an electro–hydraulic suspension system.This paper develops a dynamics model of an electric tractor-ploughing unit under complex soil conditions,leading to the proposal of an active control method for drive wheel torque and a joint control method for the traction force of the suspension system and the front-and rear-axle loads of a tractor.Finally,the tractor is prototyped and assembled,and ploughing tests are carried out.The ploughing results show that the active torque-distribution control method proposed in this study reduces the tractor slip by 14.83%and increases the traction efficiency by 10.28%compared with the average torquedistribution mode.Compared with the conventional traction control mode,the joint control method for traction and ballast proposed in this paper results in a 3.7%increase in traction efficiency,a 15.05%decrease in slip,and a 4.9%reduction in total drive motor energy consumption.This study will help to improve the operation quality and traction efficiency of electric tractors in complex soil conditions.展开更多
We present a scheme for dissipatively preparing bipartite Knill–Laflamme–Milburn(KLM)entangled state in a neutral atom system,where the spontaneous emission of excited Rydberg states,combined with the coherent popul...We present a scheme for dissipatively preparing bipartite Knill–Laflamme–Milburn(KLM)entangled state in a neutral atom system,where the spontaneous emission of excited Rydberg states,combined with the coherent population trapping,is actively exploited to engineer a steady KLM state from an arbitrary initial state.Instead of commonly used antiblockade dynamics of two Rydberg atoms,we particularly utilize the Rydberg–Rydberg interaction as the pumping source to drive the undesired states so that it is unnecessary to satisfy a certain relation with laser detuning.The numerical simulation of the master equation signifies that both the fidelity and the purity above 98%is available with the current feasible parameters,and the corresponding steady-state fidelity is robust to the variations of the dynamical parameters.展开更多
基金supported by the National Key Research and Development Plan of China(2022YFD2001201)the Beijing Postdoctoral Research Foundation(2023-ZZ-112)+1 种基金the National Natural Science Foundation of China(52272444)the Natural Science Foundation of Jiangsu Province(BK20230548).
文摘In response to the problems of excessive greenhouse-gas and particulate emissions and the low traction efficiency of conventional diesel tractors in the field,a purely electric wheel-side drive tractor was studied,including an electric motor drive system,a battery ballast system,and an electro–hydraulic suspension system.This paper develops a dynamics model of an electric tractor-ploughing unit under complex soil conditions,leading to the proposal of an active control method for drive wheel torque and a joint control method for the traction force of the suspension system and the front-and rear-axle loads of a tractor.Finally,the tractor is prototyped and assembled,and ploughing tests are carried out.The ploughing results show that the active torque-distribution control method proposed in this study reduces the tractor slip by 14.83%and increases the traction efficiency by 10.28%compared with the average torquedistribution mode.Compared with the conventional traction control mode,the joint control method for traction and ballast proposed in this paper results in a 3.7%increase in traction efficiency,a 15.05%decrease in slip,and a 4.9%reduction in total drive motor energy consumption.This study will help to improve the operation quality and traction efficiency of electric tractors in complex soil conditions.
基金the LiaoNing Revitalization Talents Program(Grant No.XLYC1907033)the Natural Science Foundation of Liaoning Province(Grant No.2023-MS-072)+1 种基金the National Natural Science Foundation of China(Grant No.11905027)the Fundamental Research Funds for the Central Universities(Grant Nos.N2209005 and N2205015)。
文摘We present a scheme for dissipatively preparing bipartite Knill–Laflamme–Milburn(KLM)entangled state in a neutral atom system,where the spontaneous emission of excited Rydberg states,combined with the coherent population trapping,is actively exploited to engineer a steady KLM state from an arbitrary initial state.Instead of commonly used antiblockade dynamics of two Rydberg atoms,we particularly utilize the Rydberg–Rydberg interaction as the pumping source to drive the undesired states so that it is unnecessary to satisfy a certain relation with laser detuning.The numerical simulation of the master equation signifies that both the fidelity and the purity above 98%is available with the current feasible parameters,and the corresponding steady-state fidelity is robust to the variations of the dynamical parameters.
