The Bucket’s Trajectory Planning And Control System Design For Hydraulic Excavator

The hydraulic excavator is one of engineering machinery, which has the most typical function, complicated structure and widely applications and plays an important role in the morden construction. With the excavation site environmental deterioration and increased diversity of mining request, research on intelligent and robotic excavator is gradually becoming a hotspot at home and abroad. It is worth noting that the trajectory planning and control technology of hydraulic excavator are the key technologies to realize automatization and intelligentiztion of hydraulic excavator.According to the development actuality of motion control of the hydraulic excavator’s manipulator and tendencies of hydraulic excavators, the trajectory planning ang control system design problem of hydraulic excavator’s bucket is discussed and studied through the example of fixed piont digging. Based on the control requirements of the hydraulic excavator’s fixed digging, the motion curve of hydraulic excavator’s bucket is analyzed, and then the coordinate of the trajectory planning and the solving method is presented. The kinematics of hydraulic excavator’s working device is analyzed, the calculation method of sloving the oil cylinders’ lengths, which related with trajectory coordinates, is described in detail. At the same time, the correlation simulation experiments are carried out. The mathematic models of the hydraulic excavator’s controlling subsystem, which consists of arm, stick and bucket, are modelled and simulated. The time domain and frequency domain of the control subsystem are analyzed in detail befor and after the addition of PID controllers. According to the analysis and simulation resultes, PID controllers are designed. The hardware design schemes of hydraulic excavator’s track control system is determined based on the CAN bus. Taking CodeSys V2.3as the software development environment, some related control programs of the lower computer are programmed by using IEC61131-3language. At last, the software design of the control system is presented.The simulation results show that the control system of hydraulic excavator’s working device after joined the PID controller, is more stable, the respose is more rapidly and the tracking performance is ideal,can be to the default control value in a short time,and can meet the actual working condition requirements.