Design Of A Control System For Concrete Leveling Machines Based On CAN Bus

With the development of national economy,the requirments of land leveling is becoming higher and higher,in terms of modern agriculture and engineering construction.At present,laser leveling machine designed by China cannot satisfy the requirement.There are many equipment nodes in the leveling machine communication system.Hence a reliable bus is necessary for communication.The CAN bus can ensure the reliability of data transmission in the control system and the task assignment will not be interfered by complicated working environment.At present,there are few studies on the protection circuit of CAN communication for leveling machines.To ensure the reliability of the leveling machine communication system,a protection circuit needs to be designed.Previous studies mainly focus on leveling machines driven by hydraulic systems.However,this system has many problems.Because the electric push rod has a simple structure and low cost,it can be used as a driving device for a small laser leveling machine.In order to drive the electric push rod of the leveling machine drive device,a corresponding motor drive circuit needs to be designed.When the leveling machine is leveling,the road condition is uneven.In order to simulate the actual running condition,a leveling machine simulation experiment platform is necessary.The main research contents and results of this paper are as follows:(1)The traditional two-sided laser control system was replaced by the single-sided laser control system using a one-side sensor measurement system.The drawing of the leveling machine test platform was designed,and the work of construction was completed.The mimic road condition experiment has been completed to verify the effectiveness of the experiment platform.(2)The scheme of the CAN bus communication system of the leveling machine was designed.The ESD protection circuit and the surge protection circuit were designed.Using the Multisim software to verify the reliability of the surge protection circuit.A logic analyzer was used to analyze datas of the protocol multi-node CAN communication and laser receiving,which verified the reliability of CAN communication.(3)The scheme of the driving module of the laser leveling machine was designed.The motor driving circuit of the laser leveling machine was built in the Altium Designer software,and the process of debugging was completed.In order to verify the feasibility of the scheme,the simulation model of the H-bridge circuit was built.The experiment of PWM driving proved that the circuit can realize the forward,reverse and speed control of the motor.(4)The measurement datas of gyroscope were compensated by magnetometer and accelerometer.The extended kalman filter algorithm was used for attitude fusion to get the optimal estimation of attitude.In order to calculate the attitude,the quaternion method was used.The incremental PID control algorithm and fuzzy PID control algorithm were designed to realize the horizontal attitude control experiment of the shovel,based on the leveling machine simulation experiment platform.The experimental results showed that the precision of fuzzy PID control algorithm was higher than incremental PID control algorithm.