Electric-powered wheelchairs have been used as a convenient transport device for elderly and disabled. Recently, a front drive type electric wheelchair that is easy for a disabled person to climb on from a bed has been focused on. However, front-drive-type wheelchairs are hard to run straight and difficult to operate because their over-steering characteristic is strong owing to free casters. If the wheelchair can be driven by an easy control stick operation, it will be a comfortable function for disabled persons. In our previous study, we proposed a front-drive-type wheelchair control method which realizes comfortable functions, i.e. driving with easy stick operation like the traditional rear-drive-type wheelchair. The proposed control system uses ideal model of electric wheelchairs. By using our proposed method, the maneuverability can be improved for realizing easy stick operation. In this paper, we evaluate the effectiveness of our proposed method by simulations and experiments on a slope with electric-powered front-drive-type wheelchair. In particular, straight-ahead stability on slope is analyzed by human driving.