The invention discloses a mechanical arm trajectory tracking control method based on a high-order sliding-mode observer. The method comprises the following steps of 1, establishing a dynamical model of an n-degree-of-freedom rotary joint rigid mechanical arm
system; 2, acquiring measurement information of joint angles q of a mechanical arm by utilizing a photoelectric
encoder, and calculating a mechanical arm trajectory
tracking error e = q - qd according to a set expected
joint angle qd; 3, establishing a global integral fast
terminal sliding mode surface according to e; 4, determining
control torque tau of joint driving motors of the mechanical arm according to the sliding mode surface and establishing a control
gain self-adaptive rate capable of being dynamically adjusted; and 5, establishing the
output feedback high-order sliding mode observer according to the
control torque tau and the joint angles q of the mechanical arm, and estimating current
angular velocity of joints and lumped disturbance. According to the method, under the situation that nonlinear uncertain items such as
system parameter perturbation, external torque interference and damping friction exist in the mechanical arm
system, the trajectory tracking control of the mechanical arm is realized only based on the measurement information of all the joint angles, and robustness of whole control process is ensured.