Study Of Auto-dig Working Trajectory Controller Of Loader’s Work Tools

As the loader is one of the main types of the engineering machines, it is applied widely among the engineering operation. However, the work of shoveling material is manipulated by operator’s controlling the handle of the arms or the bucket at present in domestic loader field. And during the process of the manual controlling, there is random at the position of unloading and shoveling. Meanwhile, due to the bucket can not flat automatically, the operator has to adjust the shoveling angle. Moreover, because of the objects of the work are complicated and changing from time to time, the loader has to vary its position too. So the efficiency of the shoveling is mostly determined by the experiences, skills and desires of the manipulators. And because of the mode of wheel-loader’s work:shovel, transfer, unload and changing direction frequently tires the operator easily, leads to low work efficiency.In order to make loader easily to operate and improve the work efficiency of the loader, and to find a trajectory with smaller energy consumption, the article do the researches that focus on the auto-dig control of the loader. The detailed elaborations as following:First, On the basis of the mechanism character of the loader, analyze the kinematics of work tools, and then set up the kinematics model. Established coordinates by using the theory of D-H. Obtained the transformation matrix of bucket relative to the frame. Achieve conversion from Cartesian coordinates to joint coordinates of the loader’s track. Then gained conversion from joint coordinates to drive space. Analyzing the manual dig mode working trajectory, and analyzing the auto-dig mode working trajectory in theory and designed the working trajectory combined with the working productivity and energy-saved. Finally gained drive equation of the lift and tilt cylinders.Second, setup an electro-hydraulic proportional control system which uses proportional reducing valve valve as pilot valve and the system realize the position control to the lift and tilt cylinder. According to characteristic of lift and tilt cylinder’s positiong control, adopt fuzzy-PID method to control the movement of the cylingders to obtain the goal work trajectory.In order to meet the requirement of the working productivity and bucket’s full-load, introduces the principle of auto-dig control strategy based on the intelligent resistance-reduce, which ensures the working efficiency of the loader.Third, the hardware of the auto-dig working trajectory controller of the work tools is designed to adapt to the hard working condition, which is based on the Infineon’s micro-computer XC167with high reliability for industrial application. The article analyzed and designed the power circuit for micro-computer system, system reset and watch-dog monitor reset circuit, CPU external clock circuit, external EEPROM circuit, input and output(I/O) circuit, CAN communication circuit, PWM control and drive power amplifier circuit, analogue signal sampling and processing circuit, speed frequency signal sampling and processing circuit, and introduce the hardware anti-interfere technique which used in the circuit designing. To meet the demand of micro-computer control system, decide the pressure transmitter and angular sensor for industrial application. And using Multisim10to simulate and analyze the analogue signal sampling and processing circuit, speed frequency signal sampling and processing circuit, to find out whether those circuits meet the requirments or not.Fourth, according to the principle of auto-dig control strategy and hardware, designed the flow charts of main control program, system initial program, inserting piles and shovelling material control sub-program, Fuzzy-PID control sub-program, read A/D data converted in XC167sub-program, read from and write into EEPROM control sub-program. Write the source program of system initial and read A/D data converted in XC167sub-program in C language. adopt the software way to add chopper frequency to the signal which control the coil of proportional reducing valve, and write the C language source program. Introduce the software anti-interfere technique which used in the program designing.