Research On 4-DOF Robot Motion Control System Based On STM32 And FPGA

Industrial robot is widely used in many fields for its high accuracy, high efficiency and versatility. Because of the general existence of dangerous operation in the petrochemical industry, it is necessary to use a robot. However, it is not feasible to use expensive robots in the petrochemical industry, which has the characteristic of low added-value of its product. Therefore, this paper carries out the basic research of 4-dof robot with low costing and high stability, and focuses on the robot motion control system and trajectory planning algorithm.The main content of this paper is as follows: Considering the requirement of robot motion control, low costing and high reliability, the paper proposes a structure based on STM32 + FPGA. In this structure, STM32 acts as the main processor to accomplish human-computer interaction, logic control and motion control. FPGA acts as the coprocessor to be used for signal acquisition and output control. Meanwhile, this paper also designs circuit of each module, and then completes the relevant circuit board production. On the basic of hardware structure, the software overall scheme is proposed and the relevant codes of each module on STM32 and FPGA are devolved.Taking the SCARA robot as the research object, this paper discusses the kinematic of SCARA robot and carries out the corresponding simulation on MATLAB. The simulation results show that the kinematics solution is correct. Meanwhile, based on kinematic model, this paper also analyzes the trajectory planning of the robot. In Cartesian space, space liner and arc trajectory planning method with a parabolic segment are discussed deeply; in the joint space, 4-3-4 polynomial trajectory interpolation method is presented and extended to be a general formula of extension 4-3-4 polynomial trajectory interpolation method. Simulation on MATLAB and experiments on experimental platform are taken. The results show that robot can run currently and smoothly according to the given requirements.On the basis of 4-3-4 polynomial trajectory interpolation method, combined with the given constraints, this paper proposes the specific method of time-optimal trajectory planning based on standard genetic algorithm. Because of the shortcomings of the standard genetic algorithm, an improved genetic algorithm is put forward and is used to optimize the time-optimal trajectory planning. Then, the simulation on MATLAB for trajectory optimization algorithm is taken. The simulation results show that the total time to complete the entire section of the trajectory reduces significantly, proving that the standard genetic algorithm and the improved genetic algorithm are both well performed. Furthermore, the improved algorithm performs better and faster. Meanwhile, the displacement, velocity and acceleration of each joint are all within a given range, indicating the feasibility and effectiveness of the trajectory optimization algorithm. The experiment carried out on the experiment platform revealed that the experiment results are consistent with the simulation results.