The invention relates to the technical field of
motor control, in particular to a low-speed large-torque control method and
system for an
industrial robot joint motor, and the method comprises the steps: collecting the
voltage of a
DC bus, each phase of current of a
stator, and the position and rotating speed of a rotor, and carrying out the coordinate transformation of each phase of current of the
stator according to the position of the rotor; obtaining d-axis current and q-axis current of the synchronous rotating coordinate
system; solving a
stator flux linkage estimation value and an
electromagnetic torque estimation value according to the d-axis current, the q-axis current and preset motor parameters, and generating a
torque error and a
flux linkage error; the
torque error passes through a torque
regulator to obtain a
load angle instruction, and the
flux linkage error and the rotating speed pass through a flux linkage
regulator to obtain a
voltage vector amplitude instruction and a
voltage vector angle instruction; generating a d-axis voltage instruction and a q-axis voltage instruction; constructing an
inverter nonlinear voltage disturbance
estimation model, defining d-axis
disturbance voltage and q-axis
disturbance voltage as
disturbance voltage states, and merging the disturbance voltage states into an extended Kalman filtering
state space model; executing extended Kalman filtering prediction and correction to obtain a d-axis disturbance voltage estimated value and a q-axis disturbance voltage estimated value; forming a
voltage compensation amount and superposing the
voltage compensation amount to obtain a compensation voltage instruction; driving pulses are generated through inverse coordinate transformation and
space vector modulation, and low-speed large-torque online compensation is achieved. According to the invention, the problems that the output pole voltage of the joint motor of the
industrial robot has unexpected
distortion and further shows control nonlinearity and the
distortion voltage is difficult to directly sense and measure can be solved.