Abstract: The traditional model prediction control algorithm for articulated wheel loaders cannot achieve forward and reverse switching driving and cannot predict turns in advance,which affects the control effect.To this end,a trajectory tracking algorithm based on expected path pre-sighting and model switching was proposed,and the impact of the algorithm on trajectory tracking accuracy and steering motor use was investigated.The path pre-sighting algorithm was used to control the steering motor in advance to reduce the over-tuning problem.The model switching was achieved by introducing a reversing mechanism into the control prediction model to achieve continuous control of forward and reverse driving.The experiments were carried out on a small loader test bench,and the results showed that:① the trajectory tracking control accuracy was basically stable within 0.05m by comparing suitable pre-sighting distance with the control corresponding to no pre-sighting,and the tracking accuracy was improved and the average speed of the steering motor was reduced by 6.42%;② the control with model reversing mechanism switching achieved continuous forward and reverse operation,and the trajectory tracking control accuracy was stable within 0.1 m or less.

Key words: articulated wheel loader, trajectory tracking, model predictive control, dynamics model

摘要： 铰接轮式装载机传统模型预测控制算法无法实现前进、倒车切换行驶,无法提前预测转弯,影响控制效果。为此,提出基于期望路径预瞄与模型切换的轨迹跟踪算法,研究该算法对轨迹跟踪精度与转向电机使用的影响。首先,采用路径预瞄算法对转向电机提前控制,减小过调问题。其次,通过在控制预测模型中引入倒车机制,实现模型切换,达到连续控制前进、倒车行驶的目的。在小型装载机试验台上开展实验,结果表明:合适的预瞄距离与无预瞄相对应的控制相比,轨迹跟踪控制精度基本稳定在0.05 m以内,跟踪精度得到了提高,转向电机平均转速降低6.42%;采用模型倒车机制切换的控制实现前进、倒车连续运行,轨迹跟踪控制精度稳定在0.1 m以内。

关键词: 铰接轮式装载机, 轨迹跟踪, 模型预测控制, 动力学模型