增程式四轮驱动电动拖拉机转矩分配策略

Torque Distribution Strategy of Extended Range Electric Tractor

针对增程式四轮驱动电动拖拉机前后轮驱动转矩分配问题,提出了一种基于模糊逻辑的转矩分配策略。通过对拖拉机犁耕机组进行受力分析,将拖拉机坡度和犁耕阻力作为模糊输入变量,拖拉机电机转矩分配因数作为模糊输出变量,设计模糊控制器。为了验证所提策略的优越性,设置了定比分配策略作为对比策略。仿真结果表明:与定比分配策略相比,本文策略将拖拉机前轮最大滑转率降低了16.5%,后轮最大滑转率仅上升了2.2%,有效地将拖拉机滑转率控制在合理范围内。

Aimed at the problem of torque distribution for the four-wheel drive extended range electric tractor front and rear wheels,torque distribution strategy based on fuzzy logic was proposed in this paper. A fuzzy controller was designed according to the force analysis for the tractor. Gradient and plowing resistance were fuzzy input variables,and the torque distribution factor of traction motor was fuzzy output variables in the controller. In order to verify the superiority of the proposed strategy,a contrast strategy named fixed ratio distribution strategy was set. Simulation results shows that the front wheel maximum slip rate under the proposed strategy is declined 16. 5% compared with the fixed ratio distribution strategy. The rear wheel maximum slip rate is only risen 2. 2%. The tractor slip rate is controlled effectively in the reasonable range.