This study proposes the use of a series elastic actuator (SEA) in a Segway to improve the stability of the tires during linear and curved driving, thus improving the comfort of the driver and ensuring driving stability. Recently, Segway has been developed continuously for intelligent mobile vehicles and the performance of Segway is being enhanced. Therefore, safety factors during the Segway driving have been considered seriously. In most of the developments and studies on Segway, the optimization and improvement of the controller component have been tackled and there are few studies on the safety devices and the stability of driving. The impact and vibration generated from the ground due to uneven road surfaces considerably influence the force exerted on the tire, which further affects driving stability. This research focuses on the control of the SEA based on the tire model to improve the driving stability of Segway. The performance of the proposed algorithm to improve the stability of the driver has been verified by straight and curved paths driving experiments with the tire model.

In this paper, two different control methods are developed for an operator-assisted mobile robotic system for high load applications. For high load applications of mobile robots, an accurate tire model that considers wheel slip needs to be studied to achieve robustness of the system response. First, a simple operator-manipulator coordination system is developed based on explicit force control. Then, a position controller for the platform is designed to minimize the effect of wheel slip on control performance and integrated with the force controller for the operator-manipulator subsystem based on a motion coordination scheme. Then, a new type of human-robot coordination control method is developed, in which robust force control of the manipulator and impedance control of the mobile platform are integrated to achieve robust response and smooth interaction between the operator, the manipulator and the mobile platform. In simulation, the developed methods are compared for control performance on following the operator's motion intention.