Research On Control Of Trajectory Tracking Of A Robotic Hydraulic Excavator

The optimized trajectory planning and trajectory tracking control of the robotic hydraulic excavator are studied in this paper. The latest research and development in mechatronic technology of hydraulic excavators is also introduced. The research direction and task of this thesis is given in the light of the present situation of WY3.5 Hydraulic Excavator in Mechanical Design Institue of Zhejiang University. At last, according to the comprehensive strategy brought out for trajectory tracking and control of the hydraulic excavator, some relative experiments have been conducted and results from experiments have been analysed. The following items are mainly introduced:1. An comprehensive strategy of trajectory tracking control of the robotic excavator is given, in the light of the strong nonlinearity of devices and hydraulic system of the robotic excavator. In the traditional trajectory planning, an optimization model is joined. The intelligent PID control based on some rules is adopted in the joint sevocontrols. And the negative control is adopted in the pump sevocontrol.2. An optimization model of trajectory planning. In traditional strategies for trajectory planning, the performance of operation and energy saving of hydraulic systems were not considered carefully. So a good control strategy with speed and acceleration optimization is brought out, and some restrains are also joined in this strategy.3. Methods of joint servcontrol. For a traditional digital PID control can not satisfy our requirements of good precision of trajectory tracking and good performance of operation, the intelligent digital PID control based on some rules is adopted in the joint sevocontrols. At the same time, Time Delay Control (TDC), which has a good robust capability and strong applicability to nonlinearity systems, is also introduced and simulated.4. Experiments about comprehensive strategies. Some experiments have been conduced on the WY3.5 Hydraulic Excavator, including multi-joints motion, line motion and triangle motion. The relative plans and methods are proved valid via the analysis of results from experiments.