A tip-over and slippage stability criterion for stair-climbing of a wheelchair robot with Variable Geometry Single Tracked Mechanism

Abstract

This paper introduces an originally designed wheelchair robot equipped with a novel type of Variable Geometry Single Tracked Mechanism (VGSTM) that can actively control the robot shape and the track tension. So it becomes possible to improve the obstacle clearing capability of the robot by adapting the robot shape for the obstacle. Tip-over and slippage for track typed mobile robots are intractable problems especially in stair-climbing, which is the most fundamental obstacle clearing performance of the wheelchair robot, because of the complex track-stair interaction. In this paper, a tip-over and slippage stability criterion is derived based on the geometric model, the static model, and the track-stair interaction analysis. The stability state of the wheelchair robot during stair-climbing is obtained by simulation.

Original Design of a Wheelchair Robot Equipped With Variable Geometry Single Tracked Mechanisms

“…However, when facing obstacles such as stairs, the locomotion of the wheelchair will be limited seriously, and this shortcoming brings great discommodity to the user. In order to improve the obstacle clearing ability especially the ability of stairclimbing, many researchers have tried to equip the * State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, China; e-mail: yu_suyang@163.com, {wangting, ycwang, cyao, xfli}@ sia.cn * * Department of Advanced Robotics, Chiba Institute of Technology, Chiba, Japan; e-mail: zhidong.wang@it-chiba.ac.jp * * * School of Mechanical Engineering, Shenyang Aerospace University, Shenyang, China 1 This paper is an extension of the paper "A tip-over and slippage stability criterion for stair-climbing of a wheelchair robot with variable geometry single tracked mechanismin in Proceeding of 2012 IEEE International Conference on Information and Automation [1]. traditional wheelchair with locomotion mechanisms of mobile robots to construct a wheelchair robot.…”

“…Therefore, in this paper, an optimal solution method of driving moments is presented based on the Lagrange dynamic model of the robot [16], and then the necessary driving moment which the driving component must supply during stair-climbing can be obtained. As to the stability analysis, different from most of existing stability criteria which focus only on the tip-over situation [17]- [20], a criterion with consideration of both the tip-over and slippage situations for the original robot is established [21], and then the stability state of the robot during stair-climbing can be evaluated.…”

Electric-powered wheelchair with stair-climbing ability

“…4 Yu et al proposed a tip over and slippage stability criterion for a variable geometry single-tracked EPW-SC based on the geometric model, the static model, and the track-stair interaction analysis, for partial tracked-based EPW-SCs. 5,79 Once tip over has occurred during the process of stair climbing, it can be very dangerous and cause personal injury to the rider. Therefore, analysis on stair-climbing stability is very important.…”

“…3,4 In addition, prevention of potential tip over and ensuring the rider's safety during stair-climbing are also necessary for EPW-SCs. 4,5 The affordability and convenience of use is important for the EPW-SCs to be widely adopted by users. In summary, the four characteristics of an ideal EPW-SC are a suitable stair-climbing mechanism maintaining low cost and lightweight, 6 a smart motion control system with high stability, a reliable tip over preventing strategy, and a convenient operation interface.…”

The synthesis of a segmented stair-climbing wheel

“…2 A very interesting principle with reconfigurable belt's outer circumference between wheel and track was introduced in Xueshan et al 3 Some of these belt undercarriages are completed with auxiliary mechanisms to raise the undercarriage up to the first stair. To this group belong also the undercarriages with belts on swinging arms.…”