Here, we propose a novel nonfragile predictive control method for an omnidirectional rehabilitative training walker. The aim of the study was to design a tracking controller that includes simultaneous constraints on the tracking errors in the position and velocity in order to guarantee safe system states for the omnidirectional walker. The nonfragile controller uses incremental control to solve the optimal quadratic program problem. The exponential stability of the system is guaranteed by constructing constraints on the trajectory‐tracking error and the velocity‐tracking error. Simulation and experimental testing were conducted to confirm the effectiveness of the proposed method and verify that it can provide safe positions and velocities when applied to control the motion of an omnidirectional walker.