In this paper, a training system that has the ability of support of human force was developed. The ability to apply programmable force in training system is important to medical application. The design of smooth curves with arbitrary shapes is useful in many application areas. The B-spline functions have become one of the most extensively used methods for the definition and representation of free from curves. The automatic load regulation based on B-spline functions was proposed and implemented to a training system. Dual disturbance observers are applied to the reactive force control. A robust control system is obtained by applying the disturbance observer loop in order to cancel any disturbance torque on the motor side. In addition, an acceleration control system attains robust reactive force control. By using step-wise disturbance observer, which considers the structure of ball screw mechanism, it is possible to obtain human force sensing with wide bandwidth. A validation experiment has been performed on a training system. From the experimental results, it generates a good realization of interaction force between human and a training system.