Large Industrial Manipulator Mechanism Design And Motion Control Simulation

As an important member in industrial robot family, large industrial manipulator was widely used in automobile manufacturing, paper making, food, glass production industries; benefited for fast response, high precision and speed control performance, AC servo was widely used in industrial robots, but because great load and deadweight existed in the moving process, a huge gravity and coupling torque propose a high demand for the AC servo system, at the same time, difficulties are made for AC servo applicated in manipulator. On this point, this paper takes a expanded study on large-scale industrial manipulator with four degrees of freedom, by the aspects of structural design, trajectory planning, and control strategy.In manipulator structure design aspect, the structure with local closed loop was adopted; in order to increasing the flexibility in the moving process, took the maximum of working space as the optimal target; in order to releasing the impact of gravity torque, the balance mechanism for shoulder joint and counter balance mechanism for elbow joint had been designed; and the stress analysis of main parts were also accomplished by the finite element software.In manipulator trajectory planning design aspect, in order to reduce the burden of motor drive system in large torque output condition, according to the relationship between motor back-EMF voltage equation and output torque in voltage equitation, established the optimal function by maximum power and variance objective function in the moving progress; To ensure the smooth character in the movement, using the five order interpolated curve as the curve between discrete points, and using matrix to solve the constraint equations, greatly simplifies the solving progress on interpolation curve parameters under lots of motion constrained conditions, and take advantages of genetic algorithm to complete trajectory parameters optimization; In order to verify the validity of the text in the trajectory planning, Adams virtual prototyping simulation platform was established, by comparing simulation, the results showed that compared to the ordinary planning trajectory, the drive system power amplitude of five interpolation which was obtained by the study, had a significantly reduced, reached the purposes of releasing drive system burden by trajectory planning.In manipulator control aspect, established a three-phase permanent magnet synchronous motor(PMSM) control model; take the large manipulator which working in a invariable trajectory as the study object, by look-up table method according to the position instruction, feedforward compensation was adopted to the conquer disturbance in the movement, established the current loop, velocity loop control model for feedforward control system; in order to verify the validity of feed-forward control method in the paper, adopted Adams virtual prototype model as the control object, and established Matlab-Adams combine simulation platform, carried out the comparison of simulation with ordinary PID control, the results illustrate that the control of large manipulator which working in a invariable trajectory can be done by the method in the paper, what is more, the control effect is manifest better than the normal PID control .