【正文】 man operators control individual joints when digging in various soil conditions. Here, the soil condition must be provided to the system before digging and the material must remain relatively homogeneous for effective digging. Unexpected inclusions in the soil can be a problem for this system to deal with. Cannon implements an augmented Autodig algorithm for dig execution in their Autonomous Loading System (ALS) which pletely automates the task of loading trucks with a mass excavator. Another Autodig approach by Shull also uses actual forces measured from the hydraulic cylinders. These forces are used to determine a force vector passing through a point on the bucket that represents the resultant material forces resisting bucket motion. A target angle is also generated on the basis of accumulated energy and then bucket motion mands are generated in response to differences in the target angle and the force vector. This approach can cause the bucket to stall when high resistive forces are encountered in plex bucket rock interaction situations. Dasys et al . describe an automated bucket loading system for a LoadHaulDump (LHD) machine that also uses feedback from the pressure sensors in the bucket’s hydraulic cylinders. This system does not use a model of the muck pile to control bucket motions, but tilts or oscillates the bucket based on the “feel” of the material being loaded. The performance characteristics of this approach are not known. A positionbased impedance control approach for operator assistance during digging with a teleoperated miniexcavator was developed by Salcudean et al . at the University of British 5 Columbia. The system follows an operator specified digging path until material resistance impedes its progress, then the impedance controller tries to follow the path as closely as possible. Alternatively, Bernold proposes an impedance controller where an optimal trajectory for the bucket is generated using a planning algorithm based on soil characteristics and soiltool interaction. Singh proposes using a trajectory planner that uses a pure position based control system during the digging process. A prediction of forces that will be encountered during digging is used to reject trajectories that exceed the limitations of the hydraulic actuators. Predicting forces in soil with unknown inclusions or in blasted rock is extremely difficult if not impossible. 6 輪式挖掘裝載機(jī)自動控制 摘要 為 輪式裝載機(jī)開發(fā) 的自動挖掘控制系統(tǒng) ，采用了基于行為的模糊邏輯控制結(jié)構(gòu)。 一個有效的自動挖掘控制系統(tǒng)的使用會